• Author / Uploaded
• mhmd

Citation preview

ANSI/AGMA 601 1 -J1 4

(Revi si on of AN SI /AG M A 601 1 -I 03)

American National Standard Speci fi cati on for H i g h

ANSI/AGMA 601 1 -J 1 4

Speed H el i cal G ear U n i ts

Copyright American Gear Manufacturers Association

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

American National Standard

Specification for High Speed Helical Gear Units ANSI/AGMA 601 1 -J1 4 Approval of an American National Standard requires verification by ANSI that the requirements for due process, consensus and other criteria for approval have been met by the standards developer. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution. The use of American National Standards is completely voluntary; their existence does not in any respect preclude anyone, whether he has approved the standards or not, from manufacturing, marketing, purchasing or using products, processes or procedures not conforming to the standards. The American National Standards Institute does not develop standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the American National Standards Institute. Requests for interpretation of this standard should be addressed to the American Gear Manufacturers Association. CAUTION NOTICE : AGMA technical publications are subject to constant improvement, revision or withdrawal as dictated by experience. Any person who refers to any AGMA Technical Publication should be sure that the publication is the latest available from the Association on the subject matter. [Tables or other self-supporting sections may be referenced. Citations should read: See ANSI/AGMA 601 1 -J1 4, Specification for High Speed Helical Gear Units, published by the American Gear Manufacturers Association, 1 001 N. Fairfax Street, Suite 500, Alexandria, Virginia 2231 4, http://www.agma.org.] Approved August 8, 201 4

ABSTRACT This standard includes design, lubrication, bearings, testing and rating for single and double helical external tooth, parallel shaft speed reducers or increasers. Units covered include those operating with at least one stage having a pitch line velocity equal to or greater than 35 meters per second or rotational speeds greater than 4500 rpm and other stages having pitch line velocities equal to or greater than 8 meters per second. Published by American Gear Manufacturers Association 1 001 N. Fairfax Street, Suite 500, Alexandria, Virginia 2231 4 Copyright © 201 4 by American Gear Manufacturers Association All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without prior written permission of the publisher. Printed in the United States of America ISBN: 978-1 -61 481 -088-9

©AGMA 201 4 – All rights reserved

Copyright American Gear Manufacturers Association

ii

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Contents Foreword ...................................................................................................................................................... vi 1 Scope ..................................................................................................................................................... 1 1 .1 Application ..................................................................................................................................... 1 2 Normative references ............................................................................................................................. 1 3 Symbols, terminology and definitions .................................................................................................... 2 3.1 Symbols ......................................................................................................................................... 2 3.2 Nomenclature ................................................................................................................................ 3 3.3 Definitions ...................................................................................................................................... 3 3.3.1 Ambient temperature ................................................................................................................. 3 3.3.2 Amplification factor, AF ............................................................................................................. 3 3.3.3 Checking stand .......................................................................................................................... 3 3.3.4 Critical speed ............................................................................................................................. 3 3.3.5 Damping coefficient ................................................................................................................... 3 3.3.6 Dynamic tooth contact pattern check ........................................................................................ 3 3.3.7 Functional test ........................................................................................................................... 4 3.3.8 Gear rated power ...................................................................................................................... 4 3.3.9 Half frequency whirl ................................................................................................................... 4 3.3.1 0 Helix modification .................................................................................................................. 4 3.3.1 1 Lateral vibration ..................................................................................................................... 4 3.3.1 2 Layout lacquer ....................................................................................................................... 4 3.3.1 3 Normal transmitted power ..................................................................................................... 4 3.3.1 4 Overload ................................................................................................................................ 4 3.3.1 5 Profile modification ................................................................................................................ 4 3.3.1 6 Service power........................................................................................................................ 4 3.3.1 7 Thrust collars ......................................................................................................................... 4 4 Design considerations ............................................................................................................................ 4 4.1 Gear rated power, Pr ..................................................................................................................... 5 4.2 High transient torque levels ........................................................................................................... 5 4.3 Torsional and lateral vibrations ..................................................................................................... 5 4.4 Tooth proportions and geometry ................................................................................................... 5 4.5 Recommended tooth flank tolerance classification ....................................................................... 5 4.6 Pinion proportions ......................................................................................................................... 6 4.7 Rotor construction ......................................................................................................................... 6 4.8 Gear housing ................................................................................................................................. 7 4.8.1 Special housing considerations ................................................................................................. 7 4.8.2 Shaft seals ................................................................................................................................. 7 4.9 Bearings ........................................................................................................................................ 7 4.9.1 Hydrodynamic bearings ............................................................................................................ 7 4.9.2 Radial bearing stability .............................................................................................................. 8 4.9.3 Thrust bearings ......................................................................................................................... 8 4.9.4 Thrust collars ............................................................................................................................. 8 4.9.5 Rolling element bearings ........................................................................................................... 9 4.1 0 Threaded fasteners ....................................................................................................................... 9 4.1 1 Shafting ......................................................................................................................................... 9 5 Rating of gears ....................................................................................................................................... 9 5.1 Rating criteria ................................................................................................................................ 9 5.2 Service factor, CSF and KSF ........................................................................................................... 9 5.3 Pitting resistance power rating ...................................................................................................... 9 5.3.1 Stress cycle factor, ZN ............................................................................................................. 1 0 5.3.2 Load distribution factor, KH ...................................................................................................... 1 0 5.3.3 Dynamic factor, Kv ................................................................................................................... 1 0 ©AGMA 201 4 – All rights reserved

Copyright American Gear Manufacturers Association

iii

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

5.4 Bending strength power rating .................................................................................................... 1 1 5.4.1 Stress cycle factor, YN ............................................................................................................. 1 2 5.5 Allowable stress numbers, σHP and σFP ...................................................................................... 1 2 5.6 Reverse loading .......................................................................................................................... 1 2 5.7 Scuffing resistance ...................................................................................................................... 1 2 6 Lubrication ........................................................................................................................................... 1 3 6.1 Design parameters ...................................................................................................................... 1 3 6.2 Choice of lubricant ...................................................................................................................... 1 3 6.2.1 Additives .................................................................................................................................. 1 4 6.2.2 Viscosity .................................................................................................................................. 1 4 6.2.3 Synthetic lubricants ................................................................................................................. 1 4 6.3 Lubrication considerations .......................................................................................................... 1 4 6.3.1 Ambient temperature ............................................................................................................... 1 4 6.3.2 Environment ............................................................................................................................ 1 4 6.3.3 Temperature control ................................................................................................................ 1 4 6.3.4 Gear element cooling and lubrication ..................................................................................... 1 4 6.3.5 Lubricant sump ........................................................................................................................ 1 5 6.3.6 Filtration ................................................................................................................................... 1 5 6.3.7 Drain lines ............................................................................................................................... 1 5 6.4 Lubricant maintenance ................................................................................................................ 1 6 6.4.1 Change interval ....................................................................................................................... 1 6 6.4.2 Water contamination ............................................................................................................... 1 6 7 Vibration and sound ............................................................................................................................. 1 6 7.1 Vibration analysis ........................................................................................................................ 1 6 7.2 Lateral critical speeds ................................................................................................................. 1 6 7.2.1 Rotor response analysis .......................................................................................................... 1 7 7.2.2 Mode shape ............................................................................................................................. 1 7 7.2.3 Analytical considerations ......................................................................................................... 1 7 7.2.4 Other forcing phenomena ....................................................................................................... 1 7 7.2.5 Amplification factor, AF ........................................................................................................... 1 8 7.2.6 Stability analysis ...................................................................................................................... 1 8 7.3 Torsional vibration analysis ......................................................................................................... 1 9 7.4 Balance ....................................................................................................................................... 1 9 7.5 Shaft vibration ............................................................................................................................. 1 9 7.5.1 Electrical and mechanical runout ............................................................................................ 1 9 7.5.2 Electrical/mechanical runout compensation ............................................................................ 1 9 7.6 Casing vibration........................................................................................................................... 20 7.7 Vibration measurement ............................................................................................................... 20 7.8 Sound measurement ................................................................................................................... 20 8 Inspection and testing .......................................................................................................................... 20 8.1 Static tooth contact inspection .................................................................................................... 20 8.2 Functional testing ........................................................................................................................ 20 8.2.1 No load testing ........................................................................................................................ 21 8.2.2 Full speed and partial load testing .......................................................................................... 21 8.2.3 Full speed and full load testing ................................................................................................ 21 8.2.3.2 Back-to-back locked torque testing. .................................................................................... 21 8.2.3.3 Back-to-back regenerative testing ....................................................................................... 21 8.2.4 Special testing ......................................................................................................................... 22 8.2.5 Power loss testing ................................................................................................................... 22 ©AGMA 201 4 – All rights reserved

Copyright American Gear Manufacturers Association

iv

AMERICAN NATIONAL STANDARD 8. 3 9

ANSI/AGMA 601 1 -J1 4

Post fu n cti on al i n specti on s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Ven d or an d pu rch aser d ata exch an g e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 9. 1

Rati on al e for d ata req u i rem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

9. 2

Docu m en t i d en ti fi cati on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

9. 3

Data provi d ed by pu rch aser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

9. 4

Proposal d ata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

9. 5

I tem s n eed i n g resol u ti on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

9. 6

Con tract d ata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

9. 7

I n stal l ati on man u al . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

9. 8

Operati on , mai n ten an ce an d tech n i cal m an u al s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

9. 9

Recom m en d ed spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

9. 1 0

Speci al tool s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Bi bl i og raph y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Annexes An n ex A Servi ce factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 An n ex B A si m pl i fi ed m eth od for veri fyi n g scu ffi n g resi stan ce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 An n ex C System s con si d erati on s for h i g h speed g ear d ri ves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 An n ex D I l l u strati ve exam pl e. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 An n ex E Effi ci en cy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 An n ex F M etal l u rg i cal con si d erati on s for cri ti cal appl i cati on s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 An n ex G Assem bl y d esi g n ati on s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 An n ex H Pu rch aser's d ata sh eet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 An n ex I G u i d el i n e for l u bri can t vi scosi ty g rad e sel ecti on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 An n ex J Assem bl y, fu n cti on al testi n g an d preservati on of g earboxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Tables Tabl e 1 - Sym bol s u sed i n eq u ati on s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Tabl e 2 - Recom m en d ed flan k tol eran ce cl ass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Tabl e 3 - Recom m en d ed m axi m u m l en g th -to-d i am eter ( Tabl e 4 - H yd rod yn am i c babbi tt beari n g d esi g n l i m i ts

1)

L/d) rati os . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

................................................................................ 8

Tabl e 5 - Dyn am i c factor as a fu n cti on of fl an k tol eran ce cl assi fi cati on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 Tabl e 6 - Recom m en d ed l u bri can ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3 Tabl e 7 - Casi n g vi brati on l evel s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Figures

Fi g u re 1 - Am pl i fi cati on factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 8

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

v

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Foreword [Th e foreword , footn otes an d an n exes, i f an y, i n th i s d ocu m en t are provi d ed for i n form ati on al pu rposes on l y an d are n ot to be con stru ed as a part of AN SI /AG M A 601 1 -J 1 4,

Gear Units. ]

Specification for High Speed Helical

Th e fi rst h i g h speed g ear u n i t stan d ard , AG M A 421 . 01 , was ad opted as a ten tati ve stan d ard i n October, 1 943.

I t con tai n ed form u l as for com pu ti n g th e d u rabi l i ty h orsepower rati n g of g eari n g , al l owabl e sh aft

stresses, an d i n cl u d ed a sh ort tabl e of appl i cati on factors.

AG M A 421 . 01 was revi sed an d ad opted as a

fu l l statu s stan d ard i n Septem ber, 1 947 an d i ssu ed as AG M A 421 . 02. Th e H i g h Speed G ear Com m i ttee beg an work on th e revi si on of AG M A 421 . 02 i n 1 951 , wh i ch i n cl u d ed : cl assi fi cati on of appl i cati on s n ot previ ou sl y l i sted ; ch an g i n g th e appl i cati on factors from “K” val u es to eq u i val en t

Service Factors; revi si on of th e rati n g formu l a to al l ow for th e u se of h eat treated g eari n g ; an d Th i s Uniform Selection Method Data

d evel op a u n i form sel ecti on m eth od for h i g h speed g ear u n i ts.

Sheet became AG M A 421 . 03A.

AG M A 421 . 03 was approved as a revi si on by th e AG M A m em bersh i p i n October, 1 954. Th e stan d ard was repri n ted as AG M A 421 . 04 i n J u n e, 1 957.

I t i n cl u d ed th e correcti on of typog raph i cal

errors an d th e ad d i ti on of a parag raph on pi n i on proporti on s an d beari n g span , wh i ch h ad been approved by th e com m i ttee for ad d i ti on to th e stan d ard at th e October, 1 955 m eeti n g . I n October, 1 959 th e Comm i ttee u n d ertook revi si on s to cover d evel opm en ts i n th e d esi g n , m an u factu re, an d operati on of h i g h speed u n i ts wi th speci fi c referen ces to h i g h h ard n ess m ateri al s an d sou n d l evel l i m i ts.

Th e revi si on s were i n corporated i n AG M A 421 . 05 wh i ch was approved by th e AG M A m em bersh i p

as of October 22, 1 963. Th e si g n i fi can t ch an g es of 421 . 06 from 421 . 05 were:

m i n i m u m pi tch l i n e speed was i n creased to 5000

feet per m i n u te (25 m eters per secon d ); stren g th an d d u rabi l i ty rati n g s were ch an g ed ; an d som e servi ce factors were ad d ed .

AG M A 421 . 06 was approved by th e H i g h Speed G ear Com m i ttee as of J u n e 27,

1 968, an d by th e AG M A m em bersh i p as of N ovem ber 26, 1 968. AN SI /AG M A 601 1 -G 92 was a revi si on of 421 . 06 approved by th e AG M A m em bersh i p i n October, 1 991 . Th e m ost si g n i fi can t ch an g es were th e ad aptati on of rati n g s per AN SI /AG M A 2001 -B88 an d th e ad d i ti on of n ormal d esi g n l i m i ts for babbi tted beari n g s.

AN SI /AG M A 601 1 -G 92 u sed “appl i cati on factor” an d n ot

“servi ce factor”. AN SI /AG M A 601 1 -H 98 was a fu rth er refi n em en t of AN SI /AG M A 601 1 -G 92. ch an g es was th e con versi on to an al l m etri c stan d ard .

On e of th e m ost si g n i fi can t

Th e rati n g m eth od s were ch an g ed to be per

AN SI /AG M A 21 01 -D04 wh i ch i s th e metri c versi on of AN SI /AG M A 2001 -D04.

To provi d e u n i form rati n g

practi ces, cl earl y d efi n ed rati n g factors were i n cl u d ed i n th e stan d ard (AN SI /AG M A 601 1 -H 98).

Wh i l e

som e eq u ati on s sl i g h tl y ch an g ed to con form to m etri c practi ces, n o su bstan ti al ch an g es were m ad e to th e rati n g practi ce for d u rabi l i ty an d stren g th rati n g .

I n ad d i ti on , m i n i m u m pi tch l i n e vel oci ty was rai sed from

25 m /s to 35 m /s an d m i n i m u m rotati on al speed i n creased to 4000 rpm . AG M A h ad reverted to th e term “servi ce factor” i n th ei r stan d ard s, wh i ch was refl ected i n AN SI /AG M A 601 1 -H 98.

Th e servi ce factor approach i s m ore d escri pti ve of en cl osed g ear d ri ve appl i cati on s an d can

be d efi n ed as th e com bi n ed effects of overl oad , rel i abi l i ty, d esi red l i fe, an d oth er appl i cati on rel ated factors.

Th e servi ce factor i s appl i ed on l y to th e g ear tooth rati n g , rath er th an to th e rati n g s of al l

com pon en ts.

Com pon en ts are d esi g n ed based on th e rated power an d th e g u i d el i n es g i ven i n th i s

stan d ard . I n con ti n u ed recog n i ti on of th e effects of scu ffi n g i n th e rati n g of th e g ear sets, ad d i ti on al i n form ati on on scu ffi n g resi stan ce was ad d ed to an n ex B of AN SI /AG M A 601 1 -H 98. AG M A 427. 01

was wi th d rawn .

Th e i n form ati on fou n d i n AG M A 427. 01

was i n cl u d ed i n an n ex D of

AN SI /AG M A 601 1 -H 98. AN SI /AG M A 601 1 -I 03 was a fu rth er refi n em en t to AN SI /AG M A 601 1 -H 98. possi bl e to con form wi th AN SI /AG M A 21 01 -D04 an d I SO stan d ard s.

Sym bol s were ch an g ed wh ere

Th e m i n i m u m rotati on al speed was

i n creased to 4500 rpm . H el i x an g l e l i mi ts were ch an g ed , an d a mi n i m u m axi al con tact rati o was ad d ed . Th e

L /D

l i m i ts were ch an g ed , an d u se of m od i fi ed h el i ces i s en cou rag ed based on th e u se of pred i cted

rotor d efl ecti on

an d

d i storti on .

Beari n g

l oad

d esi g n

l i m i ts al so ch an g ed .

For g ear tooth

referen ce was m ad e to AN SI /AG M A 201 5-1 -A01 rath er th an to AN SI /AG M A 2000-A88.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

Th e

Z

n

accu racy, an d

Y

n

l i fe

vi

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

factors now have a maximum rather than a minimum limit when the number of load cycles exceeds 1 0 1 0. A table of dynamic factor as a function of accuracy grade was added. References to AGMA oil grades were removed; now only ISO viscosity grades are listed. To facilitate communications between purchaser and vendor, an annex with data sheets was added. Realistic evaluation of the various rating factors of ANSI/AGMA 601 1 -I03 required specific knowledge and judgment which come from years of accumulated experience in designing, manufacturing and operating high speed gear units. This input has been provided by the AGMA High Speed Gear Committee. The first draft of ANSI/AGMA 601 1 -I03 was made in May, 2001 . It was approved by the AGMA membership in October, 2003. It was approved as an American National Standard on February 1 2, 2004. ANSI/AGMA 601 1 -J1 4 is a further refinement of ANSI/AGMA 601 1 -I03. For flank tolerance classification, previously referred to as accuracy grade or quality number, the referenced quality standard has been changed to ANSI/AGMA ISO 1 328-1 -B1 4. This revision expanded the definition section and provides detailed attention to improving quality and reliability of high speed gearing. The most notable changes are: - normative referral to material requirements in accordance with AGMA 923-B05 replacing ANSI/AGMA 21 01 -D04; - tightened controls on allowable and recommended filtration of lubricants; - clarified test requirements and test options; - eliminated the rotor dynamics annex and transferred it for adoption to the Sound and Vibration Committee; - expanded the annex on systems considerations for high speed gears; - introduced new material in gear efficiency annex eliminating a specific method for determining mesh and windage losses; - added an annex on metallurgical consideration for high speed gearing; - added an annex on lubrication considerations; - added an annex on procedures for assembly and functional testing of gearboxes. The first draft of AGMA 601 1 -J1 4 was made in May, 201 1 . It was approved by the AGMA membership in July 28, 201 4. It was approved as an American National Standard on August 8, 201 4. Suggestions for improvement of this standard will be welcome. They may be submitted to [email protected].

©AGMA 201 4 – All rights reserved

Copyright American Gear Manufacturers Association

vii

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

PERSONNEL of the AGMA Helical Enclosed Drives High Speed Unit Committee Chairman: John B. Amendola ............................. Artec Machine Systems

ACTIVE MEMBERS E. Martin ............................................................... Lufkin Industries, LLC J. Rinaldo ............................................................. Atlas Copco Comptec, LLC T. Praneis ............................................................. Cotta Transmission A. Swiglo .............................................................. Northern Illinois University W. Toner............................................................... Siemens Demag Delaval Turbomachinery, Inc.

©AGMA 201 4 – All rights reserved

Copyright American Gear Manufacturers Association

viii

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

American National Standard -

Specification for High Speed Helical Gear Units 1

Scope

This high speed helical gear units standard is provided as a basis for improved communication regarding: -

establishment of uniform criteria for rating;

-

guidance for design considerations; and,

-

identification of the unique features of high speed gear units.

1 .1

Application

Operational characteristics such as lubrication, maintenance, vibration limits and testing are discussed. This standard is applicable to enclosed high speed, external toothed, single and double helical gear units of the parallel axis type. Units in this classification are: -

single stage units with pitch line velocities equal to or greater than 35 meters per second or rotational speeds greater than 4500 rpm;

-

multi-stage units with at least one stage having a pitch line velocity equal to or greater than 35 meters per second and other stages having pitch line velocities equal to or greater than 8 meters per second.

When specific experience exists, this standard may be applied to gear units that operate below the limits specified above. Marine propulsion, aerospace and vehicle gearing are not covered by this standard.

2

Normative references

The following standards contain provisions that, through reference in this text, constitute provisions of this American National Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this American National Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below.

Inspection Practices -- Part 1: Cylindrical Gears -- Tangential Measurements AGMA 923-B05, Metallurgical Specifications for Steel Gearing AGMA 925-A03, Effect of Lubrication on Gear Surface Distress ANSI/AGMA 1 01 0, Appearance of Gear Teeth - Terminology of Wear and Failure ANSI/AGMA ISO 1 328-1 -B1 4, Cylindrical Gears - ISO System of Flank Tolerance Classification - Part 1: Definitions and Allowable Values of Deviations Relevant to Flanks of Gear Teeth ANSI/AGMA 21 01 -D04, Fundamental Rating Factors and Calculation Methods for Involute Spur and Helical Gear Teeth ANSI/AGMA 6000-B96, Specification for Measurement of Linear Vibration on Gear Units ANSI/AGMA 6001 -D97, Design and Selection of Components for Enclosed Gear Drives ANSI/AGMA 6025-D98, Sound for Enclosed Helical, Herringbone, and Spiral Bevel Gear Drives

AGMA 91 5-1 ,

Copyright American Gear Manufacturers Association ©AGMA 201 4

– All rights reserved

1

AMERICAN NATIONAL STANDARD AN SI /AG M A 9005-E02,

ANSI/AGMA 601 1 -J1 4

Industrial Gear Lubrication

I SO 4406: 1 999, H yd rau l i c fl u i d power -- Fl u i d s -- M eth od for cod i n g th e l evel of con tam i n ati on by sol i d parti cl es I SO 1 41 79-1 : 2001 , G ears -- Th ermal capaci ty -- Part 1 : Rati n g g ear d ri ves wi th th erm al eq u i l i bri u m at 95° C su mp tem peratu re I SO 1 4635-1 , Gears – FZG test procedures – Part 1: FZG test method A/8,3/90 for relative scuffing load carrying capacity of oils

3

Symbols, terminology and definitions

3.1

Symbols

Th e sym bol s u sed i n th i s stan d ard are sh own i n Tabl e 1 .

NOTE:

Th e symbol s an d term s con tai n ed i n th i s d ocu m en t m ay vary from th ose u sed i n oth er AG M A stan d ard s.

U sers of th i s stan d ard sh ou l d assu re th em sel ves th at th ey are u si n g th ese sym bol s an d term s i n th e man n er i n d i cated h erei n .

Table 1 - Symbols used in equations Symbol A A AF C CRE c c D d F F K K K K K K K K K L N N N N n P P ct

SF

Term Al l owabl e ampl i tu d e of u n fi l tered vi brati on Am pl i tu d e at

N

ct

Am pl i fi cati on factor Servi ce factor for pi tti n g resi stan ce

7. 5

mm

Fi g u re 1

- -

Cri ti cal respon se en vel ope Lu bri can t speci fi c h eat at (

p

Speci fi c h eat of l u bri can t

rpm

T

ou t

+

T

i n )/2

Where first used

mm

- -

h

J

Units

7. 2. 5 5. 2 Fi g u re 1

kJ /kg C°

6. 3. 4

kJ /kg C°

8. 2. 5

N om i n al beari n g bore d i ameter

mm

Pi n i on operati n g pi tch d i ameter

mm

Tabl e 4 4. 6

d

I n crem en tal d yn am i c l oad

N

5. 3. 3

t

Tran sm i tted tan g en ti al l oad

N

5. 3. 3

B

Ri m th i ckn ess factor

- -

5. 4

H

Load d i stri bu ti on factor

- -

5. 3. 2

He

M esh al i g n men t correcti on factor

- -

5. 3. 2

Hma

M esh al i g n men t factor

- -

5. 3. 2

Hmc

H el i x correcti on factor

- -

5. 3. 2

H pm

Pi n i on proporti on m od i fi er

- -

5. 3. 2

s

Si ze factor

- -

5. 3

SF

Servi ce factor for ben d i n g stren g th

- -

5. 2

v

Dyn am i c factor

- -

Face wi d th i n cl u d i n g g ap

cm

I n i ti al (l esser) speed at 0. 707

cp

Fi n al (g reater) speed at 0. 707

ct

mc

mm peak ampl i tu d e (cri ti cal )

5. 3. 3 4. 6

rpm

7. 2. 5

rpm

7. 2. 5

Rotor fi rst cri ti cal , cen ter freq u en cy

rpm

7. 2. 5

M axi m u m con ti n u ou s rotor speed

rpm

peak ampl i tu d e (cri ti cal )

L

N u m ber of stress cycl es

a

Al l owabl e tran sm i tted power for th e g ear set

ayu

Al l owabl e

tran sm i tted

power

- -

for

ben d i n g

stren g th

at

u n i ty

4. 1 5. 3. 1

kW

5. 1

kW

5. 1

servi ce factor

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

2

AMERICAN NATIONAL STANDARD

Symbol Pazu PL Pr QLUBE SJ SM Umax W Wcpl Wr YN Yθ ZN ZR ZW ΔT σFP σHP

Term Allowable transmitted power for pitting resistance at unity service factor Power loss Gear rated power Lubricant flow Diametral clearance Separation margin Amount of residual rotor unbalance per plane Individual journal static loading Half weight of coupling and spacer Total weight of rotor Stress cycle factor for bending strength Temperature factor Stress cycle factor for pitting resistance Surface condition factor for pitting resistance Hardness ratio factor for pitting resistance Change in lubricant temperature Allowable bending stress number Allowable contact stress number

ANSI/AGMA 601 1 -J1 4

Units kW

Where first used 5.1

kW kW kg/sec mm rpm g-mm kg kg kg -----C° N/mm 2 N/mm 2

8.2.5 4.1 8.2.5 Table 4 Figure 1 7.4 7.4 7.2.1 7.2.1 5.4.1 5.3 5.3.1 5.3 5.3 8.2.5 5.5 5.5

3.2 Nomenclature The terms used, wherever applicable, conform to the following standards: AGMA 904-C96, Metric Usage ANSI/AGMA 1 01 2-G05, Gear Nomenclature, Definitions of Terms with Symbols ISO 701 , International gear notation – Symbols for geometrical data 3.3 Definitions 3.3.1 Ambient temperature The temperature of the air in the immediate vicinity of the gear unit. 3.3.2 Amplification factor, AF The critical speed divided by the band width of the response frequencies at the half power point. 3.3.3 Checking stand A testing device that holds the pinion and gear very accurately in the correct position, axes parallel at the proper center distance, so they can be rotated and the contact pattern of the teeth checked. 3.3.4 Critical speed A rotor speed at which a peak vibration occurs in response to excitation. 3.3.5 Damping coefficient A characteristic of the bearings that is generally obtained from the bearing manufacturer or calculated with specialized bearing software. 3.3.6 Dynamic tooth contact pattern check A check of the tooth contact pattern after operation.

©AGMA 201 4 – All rights reserved

Copyright American Gear Manufacturers Association

3

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

3.3.7 Functional test A mechanical running test performed on the assembled gear unit.

3.3.8 Gear rated power The maximum power the gear is designed to transmit at a specified speed.

3.3.9 Half frequency whirl An instability in which the shaft whirls around the bearing axis at a frequency less than one-half shaft speed.

3.3.1 0 Helix modification An intentional design change to the shape of the lead, generally defined relative to a helix on a specified pitch cylinder.

NOTE:

Helix modification usually does not mean that the helix angle is modified. There are many possible helix modifications, including end relief, full crowning, or far more complex asymmetrical modifications such as those designed to compensate for thermal deformation and distortions expected under load.

3.3.1 1 Lateral vibration Dynamic motion that is primarily in a direction perpendicular to the shaft centerline, i.e. in a radial direction.

3.3.1 2 Layout lacquer A hard lacquer commonly used to make scribed lines more visible on smooth metal surfaces.

3.3.1 3 Normal transmitted power An optional power level specified by the purchaser.

3.3.1 4 Overload A load which is in excess of the torque equivalent to the gear rated power at rated speed.

3.3.1 5 Profile modification An intentional design change to the shape of the profile, generally defined relative to an involute in the transverse plane.

NOTE:

Profile modification usually does not mean that the profile angle is modified. One common profile modification is tip relief, used so that highly loaded gears transfer loads between teeth smoothly.

3.3.1 6 Service power The maximum installed continuous power capacity of the prime mover

3.3.1 7 Thrust collars A pair of flanges or collars on single helical pinions that overlap the sides of the gear wheel such that the axial position of the pinion is controlled by the gear wheel.

NOTE: Thrust collars are used so that a high speed thrust bearing is not needed; the pinion thrust forces are transmitted to the gear wheel where a low speed thrust bearing may be used.

4

Design considerations

This standard should be used in conjunction with appropriate AGMA standards. External loads shall be considered as acting in directions and rotations producing the most unfavorable stresses unless more specific information is available. Allowances shall be made for peak loads.

Copyright American Gear Manufacturers Association ©AGMA 201 4

– All rights reserved

4

AMERICAN NATIONAL STANDARD

4.1

ANSI/AGMA 601 1 -J1 4

Gear rated power, Pr

U n l ess speci fi cal l y ag reed to by th e pu rch aser an d ven d or, th e rated power of th e g ear u n i t sh al l be eq u al to or g reater th an th e servi ce power. For g ear u n i ts between two i tem s of d ri ven eq u i pm en t, rated power of su ch g ear u n i ts sh ou l d n orm al l y n ot be l ess th an i tem (a) or (b) bel ow, wh i ch ever i s g reater. a.

1 1 0 percen t of th e maxi m u m power req u i red by th e eq u i pm en t d ri ven by th e g ear u n i t;

b.

m axi m u m

power

of

th e

d ri ver

prorated

between

th e

d ri ven

eq u i pmen t,

based

on

n orm al

tran sm i tted power d eman d s. I f m axi m u m torq u e occu rs at a speed oth er th an rated speed , th i s torq u e an d i ts correspon d i n g speed sh al l be speci fi ed by th e pu rch aser.

M axi m u m con ti n u ou s speed ,

N

m c,

i s n orm al l y th e speed at l east

eq u al to 1 05% of th e rated speed for vari abl e speed u n i ts an d i s th e rated speed for con stan t speed u n i ts. Al l com pon en ts sh al l be capabl e of h an d l i n g both th e m axi m u m torq u e and th e rated power.

4.2

High transient torque levels

Wh ere u n u su al torq u e vari ati on s d evel op peak l oad s wh i ch exceed 20 percen t of th e torq u e of th e rated power, th e mag n i tu d e an d freq u en cy of su ch torq u e vari ati on s sh ou l d be eval u ated wi th reg ard to th e en d u ran ce

an d

yi el d

properti es

of

th e

m ateri al s

u sed .

See

an n ex

C

of th i s

stan d ard

an d

al so

AN SI /AG M A 21 01 -D04, cl au se 1 6. 3.

4.3

Torsional and lateral vibrations

Wh en an el asti c system i s su bj ected to extern al l y appl i ed , cycl i c or h arm on i c forces, th e peri od i c m oti on th at resu l ts i s cal l ed forced vi brati on .

For th e systems i n wh i ch h i g h speed g ears are typi cal l y u sed , two

m od es of vi brati on are n orm al l y con si d ered . a.

Lateral vi brati on , wh i ch con si d ers sh aft d yn am i c moti on th at i s i n a d i recti on perpen d i cu l ar to th e

b.

Torsi on al vi brati on , wh i ch con si d ers th e am pl i tu d e m od u l ati on of torq u e measu red peak to peak

sh aft cen terl i n e; an d

referen ced to th e axi s of rotati on . I n certai n cases, axi al or l on g i tu d i n al vi brati on m i g h t al so be con si d ered . Becau se of th e wi d e vari ati on of g ear d ri ven system s, cl au se 7 of th i s stan d ard ou tl i n es areas wh ere proper assessm en t of th e system m ay be n ecessary.

I n ad d i ti on , respon si bi l i ty sh al l be cl earl y d el i n eated

between th e ven d or an d pu rch aser.

4.4

Tooth proportions and geometry

An y practi cal combi n ati on of tooth h ei g h t, pressu re an g l e an d h el i x an g l e m ay be u sed . recom m en d ed

th at th e

g ears

h ave

a

minimum

workin g

d epth

of 1 . 80

ti m es

th e

H owever, i t i s

n ormal

m od u l e,

a

m axi m u m n orm al pressu re an g l e of 25 d eg rees, a h el i x an g l e of 5 to 45 d eg rees, an d a mi n i m u m axi al con tact rati o of 1 . 1 per h el i x.

4.5

Recommended tooth flank tolerance classification

Previ ou sl y fl an k tol eran ce cl assi fi cati on was referred to as accu racy g rad e or q u al i ty n u m ber.

Tabl e 2

presen ts recom m en d ed AN SI /AG M A I SO 1 328-1 -B1 4 fl an k tol eran ce cl ass as a fu n cti on of pi tch l i n e vel oci ty.

Based on th e experi en ce an d appl i cati on , oth er fl an k tol eran ce cl asses m ay be appropri ate.

Table 2 - Recommended flank tolerance class ANSI/AGMA ISO 1 328-1 -B1 4 Pitch line velocity, m/s flank tolerance class 35 –1 00

5

1 00 – 1 50

4

Over 1 50

3

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

5

AMERICAN NATIONAL STANDARD

4.6

ANSI/AGMA 601 1 -J1 4

Pinion proportions

L/d) rati os for m ateri al h ard en i n g m eth od s i n cu rren t u se. L/d rati o m ay be acceptabl e i f th e rati n g i s based on a face wi d th correspon d i n g to th e L/d rati o i n th e tabl e. G en eral l y, h i g h er L/d rati os are perm i tted wh en an al yti cal l oad d i stri bu ti on m eth od s are em pl oyed th at yi el d l oad d i stri bu ti on val u es, K , th at are l ess th an th e val u e cal cu l ated per 5. 3. 2 at th e m axi m u m L/d rati o per Tabl e 3 an d th e proposal to th e pu rch aser i n cl u d es n oti ce an d j u sti fi cati on of th e L/d rati o to be u sed . Th e an al yti cal meth od sh ou l d i n cl u d e, bu t n ot be l i m i ted to, ben d i n g an d torsi on al

Tabl e 3 presen ts m axi m u m l en g th -to-d i am eter ( H i g h er

H

d efl ecti on an d th erm al d i storti on . No

L/d

matter wh at th e

rati o

i s,

i f th e

total

h el i x m i sm atch ,

i n cl u d i n g

com bi n ed

ben d i n g ,

torsi on al

d efl ecti on an d th erm al d i storti on of th e tooth an d rotor, based on th e g ear rated power, exceed s 25 th rou g h

h ard en ed

g ears,

or 1 5

μm

for case

or su rface

h ard en ed

g ears,

th en

an

μm

appropri ate

for

h el i x

m od i fi cati on sh ou l d be appl i ed i n ord er to red u ce th e total m i sm atch to a m ag n i tu d e bel ow th ese val u es at g ear rated power. face wi d th . d i storti on .

Th e mod i fi cati on i s i n ten d ed to provi d e a u n i form l oad d i stri bu ti on across th e en ti re

G ears wi th pi tch l i n e vel oci ti es i n excess of 1 00 m /s are parti cu l arl y su scepti bl e to th ermal Con si d erati on sh ou l d be g i ven to th e rel ati on sh i p of h el i x m od i fi cati on s to g ear tooth accu racy;

ti g h ter h el i x tol eran ces m ay be appropri ate.

I n ad d i ti on , th e profi l e of th e pi n i on or g ear wh eel sh ou l d be

m od i fi ed wh en n ecessary to com pen sate for ben d i n g d efl ecti on s an d th erm al d i storti on . Wh en operati n g con d i ti on s oth er th an g ear rated power are speci fi ed by th e pu rch aser, su ch as th e n ormal tran sm i tted power, th e ven d or sh al l con si d er i n th e an al ysi s th e l en g th of ti m e an d l oad ran g e at wh i ch th e g ear u n i t wi l l operate at each con d i ti on so th at th e correct h el i x m od i fi cati on can be d eterm i n ed . Wh en con tact ch ecks are to be fu rn i sh ed on g ears wi th h el i x or profi l e mod i fi cati on s, th e pu rch aser an d ven d or sh al l ag ree on th e acceptabl e ran g e of tooth con tact pattern s obtai n ed i n th e ch ecki n g stan d , h ou si n g , or test stan d .

4.7

Rotor construction

Several con fi g u rati on s m ay be appl i ed i n th e con stru cti on of rotors.

Th e m ost com mon l y u sed are l i sted

bel ow: -

I n teg ral sh aft an d g ear el em en t.

Th i s con fi g u rati on i s com m on l y u sed for pi n i on s, sm al l er g ears, or

rotati n g el emen ts operati n g above a pi tch l i ne vel oci ty of 1 50 meters per secon d .

Th e pi n i on or g ear,

i n teg ral wi th i ts sh aft, i s m ach i n ed from a si n g l e bl an k; -

Sol i d bl an k sh ru n k on a sh aft.

Th e sh ri n k fi t m ay be u sed ei th er wi th or wi th ou t a m ech an i cal torq u e

tran sm i tti n g d evi ce (su ch as key or spl i n e).

Wh en n o torq u e tran sm i tti n g d evi ce i s u sed , th e sh ri n k fi t

sh al l provi d e am pl e capaci ty to tran sm i t torq u e wh en con si d eri n g cen tri fu g al an d th ermal effects. Wh en a torq u e tran sm i tti n g d evi ce i s u sed , th e sh rin k fi t sh al l provi d e am pl e l ocati on su pport wh en con si d eri n g cen tri fu g al an d th erm al effects; -

Fabri cated g ear. wel d ed g ear.

A forg ed ri m i s wel d ed d i rectl y to th e fabri cated su bstru ctu re prod u ci n g a on e-pi ece

Th e sh aft m ay be a part of th e wel d m en t.

con si d er cen tri fu g al an d th erm al stresses an d fati g u e l i fe.

Fabri cated g ears sh ou l d be an al yzed to M axi m u m pi tch l i n e vel oci ty for wel d ed

g ear con stru cti on i s 1 30 meters per secon d ; -

Forg ed ri m sh ru n k on to a su bstru ctu re. sh aft m ay be a part of th e su bstru ctu re.

Th e su bstru ctu re m ay be forg ed , cast, or fabri cated .

Th e

Sh ru n k ri m s sh al l con si d er stresses an d torq u e tran sm i tti n g

capaci ty d u e to fi t, cen tri fu g al , an d th erm al effects (refer to sol i d bl an k sh ru n k on sh aft above).

Th e

n ormal d esi g n l i m i t for th i s type of con stru cti on i s 60 m eters per secon d . Com bi n ati on s of th e above are often u sed on m u l ti stag e u n i ts.

Table 3 - Recommended maximum length-to-diameter (L/d) ratios Maximum L/d ratio Hardening method Double helical Single helical Th rou g h h ard en ed

2. 2

1 .6

Case or su rface h ard en ed

2. 0

1 .6

NOTE: L = face wi d th i n cl u d i n g g ap, mm ; d = pi n i on operati n g pi tch d i am eter, mm

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

6

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Stresses an d d efl ecti on s at h i g h speed s often d i ctate l i m i ts for a speci fi c type of con stru cti on .

H igh

pi tch l i n e vel oci ty, especi al l y wh en combi n ed wi th h i g h l oad s, m ay req u i re speci al m ateri al speci fi cati on s an d /or testi n g . i n fl u en ce on

Con stru cti on

th e

stress.

featu res su ch

as h ol es i n th e g ear bod y sh ou l d

Th e i n fl u en ce of real

or vi rtu al

i n cl u si on s

be an al yzed

for th ei r

an d /or cracks m ay n eed

to be

con si d ered u si n g th e m eth od s of fractu re m ech an i cs, wi th testi n g of th e m ateri al to en su re th at th ere are n o i n cl u si on s

g reater th an

th e

assu med

m axi m u m.

Overal l ,

a

carefu l

an al ysi s

of actu al

operati n g

stresses an d d efl ecti on sh ou l d be m ad e to en su re rel i abl e operati on .

4.8

Gear housing

Th e g ear h ou si n g sh ou l d be d esi g n ed to provi d e a su ffi ci en tl y ri g i d en cl osed stru ctu re for th e rotati n g el em en ts th at en abl es th em to tran sm i t th e l oad s i m posed by th e system an d protects th em from th e en vi ron m en t i n wh i ch th ey wi l l operate.

Th e ven d or's d esi g n of th e h ou si n g sh al l provi d e for proper

al i g n m en t of th e g eari n g wh en operati n g u n d er th e u ser's speci fi ed th erm al con d i ti on s, an d th e torsi on al , rad i al an d th ru st l oad i n g s appl i ed to i ts sh aft exten si on s.

I n ad d i ti on , i t sh ou l d be d esi g n ed to faci l i tate

proper l u bri can t d rai n ag e from th e g ear m esh an d beari n g s. Th e u ser's d esi g n of th e su pporti n g stru ctu re sh al l m ai n tai n proper an d stabl e al i g n m en t of th e g eari n g . Al i g n m en t sh ou l d

con si d er al l

speci fi ed

torsi on al ,

rad i al

an d

th ru st l oad i n g s,

an d

th ermal

con d i ti on s

presen t d u ri n g operati on .

4.8.1

Special housing considerations

Certai n appl i cati on s m ay be su bj ected to operati n g con d i ti on s req u i ri n g speci al con si d erati on .

Som e of

th ese operati n g con d i ti on s are: -

tem peratu re vari ati on s i n th e vi ci n i ty of th e g ear u n i t;

-

rel ati ve th ermal g rowth between m ati n g system com pon en ts;

-

en vi ron m en tal el em en ts th at wi l l attack th e u n i t h ou si n g , rotati n g com pon en ts, beari n g s or l u bri can t;

-

i n ad eq u ate su pport for th e h ou si n g ;

-

h i g h pi tch l i n e vel oci ti es wh i ch m ay affect l u bri can t d i stri bu ti on , create excessi ve tem peratu re ri se, or cau se oth er ad verse con d i ti on s.

4.8.2 Shaft seals Wh ere sh afts pass th rou g h th e h ou si n g , th e h ou si n g s sh al l be eq u i pped wi th seal s an d d efl ectors th at sh al l effecti vel y retai n l u bri can t i n th e h ou si n g an d preven t en try of forei g n materi al i n to th e h ou si n g . Easi l y repl aceabl e l abyri n th en d seal s an d d efl ectors are preferred . m ad e of n on -sparki n g m ateri al s. speed s

to

be

a

fi re

Th e seal s an d d efl ectors sh al l be

Li p seal s h ave a very fi n i te l i fe an d can g en erate en ou g h h eat at h i g h er

h azard .

Su rface

vel oci ty

sh ou l d

be

kept

wi th i n

th e

seal

m an u factu rer's

recom m en d ati on .

4.9

Bearings

Proper d esi g n of beari n g s i s cri ti cal to th e operati on of h i g h speed en cl osed d ri ve u n i ts.

Th e beari n g

d esi g n sh al l con si d er th e g ear rated power. Rad i al beari n g s are n orm al l y of th e h yd rod yn am i c sl eeve or pad type. l an d , tapered l an d , or ti l ti n g pad type.

Th ru st beari n g s are u su al l y fl at

Rol l i n g el emen t beari n g s are occasi on al l y u sed .

Beari n g d esi g n

sh al l con si d er start-u p an d u n l oad ed con d i ti on s.

4.9.1

Hydrodynamic bearings

H yd rod yn am i c beari n g s sh al l be l i n ed wi th su i tabl e beari n g materi al , su ch as ti n an d l ead based babbi tts. Ti n al l oy i s u su al l y preferred over l ead al l oys becau se of i ts h i g h er corrosi on resi stan ce, easi er bon d i n g , an d better h i g h tem peratu re ch aracteri sti cs.

H yd rod yn am i c beari n g s sh al l h ave a ri g i d steel or oth er

su i tabl e m etal l i c backi n g , an d be properl y i n stal l ed an d secu red i n th e h ou si n g ag ai n st axi al an d rotati on al m ovem en t.

Beari n g s are g en eral l y su ppl i ed spl i t for ease of assem bl y.

Sel ecti on of th e parti cu l ar d esi g n

(sl eeve, pad type or l an d beari n g ) sh al l be based on eval u ati on of su rface vel oci ty, su rface l oad i n g , h yd rod yn am i c fi l m th i ckn ess, cal cu l ated beari n g tem peratu re, l u bri can t vi scosi ty, l u bri can t fl ow rate, an d beari n g stabi l i ty.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

7

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

H eat i s g en erated as a resu l t of l u bri can t sh ear.

Tem peratu re i s reg u l ated by con trol l i n g th e l u bri can t fl ow

th rou g h th e beari n g an d extern al cool i n g of th e l u bri can t.

Th e an ti ci pated peak babbi tt tem peratu re as

rel ated to beari n g l u bri can t d i sch arg e tem peratu res sh ou l d be kept wi th i n a ran g e th at i s compati bl e wi th th e babbi tt an d l u bri can t ch aracteri sti cs.

See Tabl e 4 for d esi g n l i mi ts.

4.9.2 Radial bearing stability H yd rod yn am i c rad i al beari n g s sh al l be d esi g n ed su ch th at d am ag i n g sel f-g en erated i n stabi l i ti es (e. g . , h al f freq u en cy wh i rl ) d o n ot occu r at an y an ti ci pated operati on al l oad or speed .

H yd rod yn ami c i n stabi l i ty

occu rs wh en a j ou rn al d oes n ot retu rn to i ts establ i sh ed eq u i l i bri u m posi ti on after bei n g m om en tari l y d i spl aced .

Di spl acemen t i n trod u ces an i n stabi l i ty i n wh i ch th e sh aft wh i rl s arou n d th e beari n g axi s at l ess

th an on e-h al f j ou rn al speed .

Kn own as “h al f freq u en cy wh i rl ”, th i s i n stabi l i ty m ay occu r i n l i g h tl y l oad ed

h i g h speed beari n g s.

4.9.3 Thrust bearings Th ru st beari n g s sh al l be fu rn i sh ed wi th al l g ear u n i ts u n l ess oth erwi se speci fi ed .

A th ru st beari n g i s

u su al l y provi d ed on l y on th e l ow speed sh aft for al l d ou bl e h el i cal g ears an d on si n g l e h el i cal g ears fi tted wi th th ru st col l ars (see 4. 9. 7).

Th ru st beari n g s are g en eral l y provi d ed on each sh aft for al l si n g l e h el i cal

g ears n ot fi tted wi th th ru st col l ars.

I f th e axi al posi ti on of an y of th e sh afts d epen d s on i tems ou tsi d e th e

g ear u n i t, th e pu rch aser an d ven d or sh al l ag ree to th e arran g em en t rel ati ve to th e th ru st beari n g s. Wh en g ear u n i ts are su ppl i ed wi th ou t th ru st beari n g s, som e type of en d fl oat l i mi tati on sh al l be provi d ed at

sh aft

cou pl i n g s

to

m ai n tai n

posi ti ve

axi al

posi ti on i n g

of th e

g ear

rotors

an d

con n ected

rotors.

Provi si on s to preven t con tact of th e rotati n g el emen ts wi th th e g ear casi n g sh al l be provi d ed u n l ess oth erwi se speci fi cal l y ag reed to by th e pu rch aser. Th e d esi g n of a h yd rod yn am i c beari n g to su stai n th ru st i s as com pl i cated as th e d esi g n of a rad i al h yd rod yn am i c beari n g .

Com pl ete an al ysi s req u i res con si d erati on

beari n g materi al , l oad capaci ty, speed an d sti ffn ess. possi bi l i ty of torq u e l ock-u p l oad s from cou pl i n g s.

of h eat g en erati on ,

l u bri can t fl ow,

Th ru st beari n g l oad capaci ty sh ou l d con si d er th e

Wh en oth er extern al th ru st forces are an ti ci pated , th e

ven d or sh al l be n oti fi ed of th ei r m ag n i tu d es.

4.9.4 Thrust collars Th ru st col l ars m ay be u sed on si n g l e h el i cal g ears to m ai n tai n al i g n m en t an d tran sfer axi al forces from th e pi n i on to th e g ear wh eel .

Th e th ru st col l ars exten d beyon d th e pi n i on ou tsi d e d i ameter an d typi cal l y

h ave a con i cal sh ape th at con tacts a si m i l arl y sh aped su rface on th e m ati n g g ear ri m at a d i am eter bel ow th e root d i ameter of th e g ear.

Type of bearing

Oth er d esi g n s al so exi st an d m ay be u sed .

Table 4 - Hydrodynamic babbitt bearing design limits1 ) Minimum lubricant Measured bearing Maximum velocity, 3) Projected unit 3) 2 2) 3) load, N/mm film thickness, mm temperature, °C m/s

Rad i al beari n g -

Fi xed g eometry

3. 8

0. 020

115

1 00

-

Ti l ti n g pad

4. 2

0. 020

115

1 25

0. 020

115

1 25

Th ru st beari n g s -

Tapered l an d

2. 5

-

Fl at face

0. 5

N /A

115

50

-

Ti l ti n g pad

3. 5

0. 01 5

115

1 25

NOTE:

Tabl e l i m i ts wi l l g en eral l y n ot occu r al l tog eth er; on e parameter al on e m ay d i ctate th e d esi g n . 1)

Li m i ts are for babbi tt on steel backi n g .

permi ssi bl e.

Wh en oth er m ateri al s are u sed , establ i sh ed l i mi ts for th ese m ateri al s are

Beari n g cl earan ces sh ou l d be ch osen to yi el d proper tem peratu re, h i g h sti ffn ess an d stabi l i ty, as wel l

as to en su re ad eq u ate cl earan ce to cope wi th th erm al g rad i en ts, wh eth er stead y, stati c, or tran si en t. rati o of d i am etral cl earan ce (

S) J

to th e n om i n al bore si ze (

D ), S /D J

J

J,

Th e averag e

for rad i al beari n g s i s approxi m atel y 0. 002

m m /m m . 2)

Beari n g tem peratu re m easu remen ts are taken i n th e m etal l i c backi n g materi al wi th i n 3 m m of th e backi n g

m ateri al /babbi tt i n terface at th e h ottest operati on al zon e of th e beari n g ci rcu m feren ce. 3)

H i g h er val u es are acceptabl e i f su pported ei th er wi th speci al en g i n eeri n g or testi n g an d fi el d experi en ce.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

8

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

4.9.5 Rolling element bearings Sel ecti on of rol l i n g el em en t beari n g s sh al l be based u pon th e appl i cati on req u i rem en ts an d th e beari n g m an u factu rer's recom m en d ati on s an d rati n g meth od s.

For n orm al appl i cati on s, an

L

10

l i fe of 50, 000

h ou rs m i n i m u m i s req u i red at g ear rated power.

4.1 0 Threaded fasteners Refer to AN SI /AG M A 6001 -E08, cl au se 9.

4.1 1 Shafting Th e pi n i on an d g ear sh afts may n orm al l y be d esi g n ed for th e m axi m u m ben d i n g an d maxi m u m torsi on al sh ear

stresses

at

th e

g ear

rated

power

by

th e

appropri ate

AN SI /AG M A 6001 -E08, cl au se 5, or oth er eq u i val en t stan d ard s.

m eth od s

an d

al l owabl e

val u es

from

To en su re th at th e sh aft i s n ot u n d er or

oversi zed , oth er avai l abl e an al ysi s m eth od s m ay be u sed for a m ore i n d epth stu d y.

5

Rating of gears

5.1

Rating criteria

Th e pi tti n g resi stan ce power rati n g an d ben d i n g stren g th power rati n g for each g ear m esh i n th e u n i t i s cal cu l ated

per AN SI -AGM A 21 01 -D04

u si n g

th e factors speci fi ed

in

th i s cl au se.

Th e l owest val u e

obtai n ed sh al l be u sed as th e al l owabl e tran sm i tted power of th e g ear set. Th e al l owabl e tran sm i tted power for th e g ear set,

P  th e l e sser of a

P C

a zu SF

an d

P K

P , i s d eterm i n ed : a

a yu SF

(1 )

wh ere

P P C K

ayu

C i s al l owabl e tran sm i tted power for ben d i n g stren g th at u n i ty servi ce factor ( K

SF

i s servi ce factor for pi tti n g resi stan ce; recom m en d ed val u es are sh own i n an n ex A;

SF

i s servi ce factor for ben d i n g stren g th ; recom men d ed val u es are sh own i n an n ex A.

azu

i s al l owabl e tran sm i tted power for pi tti n g resi stan ce at u n i ty servi ce factor (

SF

SF

= 1 . 0); = 1 . 0);

Th e g ear rated power sh al l be l ess th an , or eq u al to, th e al l owabl e tran sm i tted g earset power rati n g :

P P r

(2)

a

wh ere

P

r

i s g ear rated power, kW.

I t i s recog n i zed th at al l pri m e m overs h ave overl oad capaci ty, wh i ch sh ou l d be speci fi ed .

5.2

Service factor, CSF and KSF

Th e servi ce factor i n cl u d es th e com bi n ed effects of overl oad , rel i abi l i ty, an d oth er appl i cati on rel ated i n fl u en ces.

Th e AG M A servi ce factor u sed i n th i s stan d ard d epen d s on experi en ce acq u i red i n each

speci fi c appl i cati on . I n d eterm i n i n g th e servi ce factor, con si d erati on sh ou l d be g i ven to th e fact th at system s d evel op a peak torq u e, wh eth er from th e pri m e m over, d ri ven m ach i n ery, or tran si ti on al system vi brati on s, th at i s g reater th an th e n om i n al torq u e. Wh en an acceptabl e servi ce factor i s n ot kn own from experi en ce, th e val u es sh own i n an n ex A sh ou l d be u sed as m i n i m u m al l owabl e val u es.

5.3

Pitting resistance power rating

Th e pi tti n g resi stan ce of g ear teeth i s con si d ered to be a H ertzi an con tact fati g u e ph en omen on .

I n i ti al

pi tti n g an d d estru cti ve pi tti n g are i l l u strated an d d i scu ssed i n AN SI /AG M A 1 01 0.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

9

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Th e pu rpose of th e pi tti n g resi stan ce form u l a i s to d eterm i n e a l oad rati n g at wh i ch d estru cti ve pi tti n g of th e teeth d oes n ot occu r d u ri n g th ei r d esi g n l i fe.

Rati n g s for pi tti n g resi stan ce are based on th e form u l as

d evel oped by H ertz for con tact pressu re between two cu rved su rfaces, m od i fi ed for th e effect of l oad sh ari n g between ad j acen t teeth . Th e pi tti n g resi stan ce power rati n g for g eari n g wi th i n th e scope of th i s stan d ard sh al l be d eterm i n ed by th e rati n g m eth od s an d proced u res of AN SI /AG M A 21 01 -D04, cl au se 1 0, wh en u si n g servi ce factors, wi th th e val u es for factors as speci fi ed i n th i s cl au se an d cl au ses 5. 3. 1 th rou g h 5. 3. 3:

Z Y K Z Z K K 5.3.1

Z = 1 . 0; Y = 1 . 0;

W

i s h ard n ess rati o factor,

θ

i s tem peratu re factor,

s

i s si ze factor,

R

i s su rface con d i ti on factor,

N

i s stress cycl e factor (see 5. 3. 1 );

K

s

W

θ

= 1 . 0;

Z

R

= 1 . 0;

H

i s l oad d i stri bu ti on factor (see 5. 3. 2);

v

i s d yn am i c factor (see 5. 3. 3).

Stress cycle factor, ZN Stress cycl e factor, Z , i s cal cu l ated by th e l ower cu rve of fi g u re 1 7 of AN SI /AG M A 21 01 -D04, an d sh ou l d N

be based on a m i n i m u m of 40 000 h ou rs of servi ce at rated operati n g speed .

Z

N

 2.466 nL0.056

(3)

wh ere

n

L

i s n u m ber of stress cycl es.

Wh en th e n u m ber of stress cycl es exceed s 1 0

10

(i . e. , speed above 41 67 rpm for 40 000 h ou rs),

Z

N

sh ou l d

be l ess th an or eq u al to 0. 68. I f l ess th an 40 000 h ou rs i s u sed for rati n g , i t sh al l be wi th th e speci fi c approval of th e pu rch aser an d sh al l be so stated al on g wi th th e rati n g .

5.3.2 Load distribution factor, KH K i s th e l oad d i stri bu ti on factor. Val u es are to be per AN SI /AG M A 21 01 -D04. H

Th e fol l owi n g val u es sh al l

be u sed wi th th e em pi ri cal m eth od :

K

Hma

K

Hmc

K

H pm

K

He

i s m esh al i g n m en t factor.

U se val u es from cu rve 3, preci si on en cl osed g ear u n i ts, of fi g u re 7 an d

tabl e 2 of AN SI /AG M A 21 01 -D04; i s h el i x correcti on factor,

K

H m c=

0. 8;

i s pi n i on proporti on factor,

K

H pm =

1 . 0;

i s m esh al i g n m en t correcti on factor,

K

He

 

= 0. 8.  

Th e val u e u sed for

NOTE:

K

H

sh al l n ot be l ess th an 1 . 1 .

Th e above em pi ri cal rati n g m eth od assu m es properl y m atch ed h el i x wh eth er u n m od i fi ed or m od i fi ed ,

teeth cen tral to th e beari n g span an d tooth con tact ch ecked at assem bl y wi th con tact ad j u stmen ts as req u i red . th ese con d i ti on s are n ot met,

or for wi d e face g ears,

d eterm i n e l oad d i stri bu ti on factor.

If

i t may be d esi rabl e to u se an an al yti cal approach to

AGM A 927 provi d es on e su ch approach .

5.3.3 Dynamic factor, Kv Dyn am i c factors accou n t for i n tern al l y g en erated g ear tooth d yn am i c l oad s, wh i ch are cau sed by g ear tooth m esh i n g acti on at a n on -u n i form rel ati ve an g u l ar vel oci ty. Th e d yn am i c factor i s th e rati o of tran sm i tted tan g en ti al tooth l oad to th e total tooth l oad , wh i ch i n cl u d es th e d yn am i c effects.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

10

AMERICAN NATIONAL STANDARD

K

v



F

d

ANSI/AGMA 601 1 -J1 4

 Ft

F

t

(4)

wh ere

F

d

i s i n cremen tal d yn am i c tooth l oad d u e to th e d yn am i c respon se of th e g ear pai r to tran sm i ssi on error exci tati on , N ;

F

t

i s tran sm i tted tan g en ti al l oad , N .

Dyn am i c forces on g ear teeth resu l t from g ear tran sm i ssi on error.

Th e tran sm i ssi on error i s cau sed by:

-

i n h eren t vari ati on s i n g ear accu racy as m an u factu red ;

-

g ear tooth d efl ecti on s wh i ch are d epen d en t on th e vari abl e m esh sti ffn ess an d th e tran sm i tted l oad .

Th e d yn am i c respon se to tran sm i ssi on error exci tati on i s i n fl u en ced by: -

m asses of th e g ears an d con n ected rotors;

-

sh aft an d cou pl i n g sti ffn ess;

-

d ampi n g ch aracteri sti cs of th e rotor an d beari n g system .

Th e AGM A fl an k tol eran ce cl assi fi cati on per AN SI /AG M A I SO 1 328-1 -B1 4, speci fi cal l y tooth el em en t tol eran ces for pi tch an d profi l e, an d th e pi tch l i n e vel oci ty m ay be u sed as param eters to g u i d e th e sel ecti on of d yn am i c factors.

Wi th i n th e 1 . 09 to 1 . 1 5 d yn am i c factor ran g e, th e tren d i s for

K

v

to vary i n

n earl y a d i rect rel ati on sh i p wi th fl an k tol eran ce cl asses from 2 to 5 as sh own i n Tabl e 5. Th e d yn am i c factor,

K, v

d oes n ot accou n t for d yn am i c tooth l oad s wh i ch m ay occu r d u e to torsi on al or

l ateral n atu ral freq u en ci es.

System d esi g n s sh ou l d avoi d h avi n g su ch n atu ral freq u en ci es cl ose to an

exci tati on freq u en cy associ ated wi th an operati n g speed , si n ce th e resu l ti n g g ear tooth d yn am i c l oad s can be very h i g h . Refer to AN SI /AG M A 21 01 -D04 for ad d i ti on al con si d erati on s i n fl u en ci n g d yn am i c factors.

5.4

Bending strength power rating

Th e i n ten t of th e AG M A stren g th rati n g form u l a i s to d eterm i n e th e l oad wh i ch can be tran sm i tted for th e d esi g n l i fe of th e g ear d ri ve wi th ou t cau si n g root fi l l et cracki n g or fati g u e fai l u re. Th e g ear ri m th i ckn ess sh al l be su ffi ci en t for th e cal cu l ated ri m th i ckn ess factor to be 1 . 0 per AN SI /AG M A 21 01 -D04 an n ex B. Occasi on al l y, m an u factu ri n g tool m arks, wear, su rface fati g u e, or pl asti c fl ow m ay l i m i t ben d i n g stren g th d u e to stress con cen trati on arou n d l arg e, sh arp corn ered pi ts or wear steps on th e tooth su rface. Th e ben d i n g stren g th power rati n g for g eari n g wi th i n th e scope of th i s stan d ard sh al l be d eterm i n ed by th e rati n g m eth od s an d proced u res of AN SI /AG M A 21 01 -D04, cl au se 1 0, wh en u si n g servi ce factors, wi th th e val u es for factors as speci fi ed i n th i s cl au se an d cl au ses 5. 4. 1 , 5. 3. 3 an d 5. 3. 2:

Yθ K K Y K K

i s tem peratu re factor,

K

Yθ = 1 . 0;

s

i s si ze factor,

B

i s ri m th i ckn ess factor,

N

i s stress cycl e factor (see 5. 4. 1 );

v

i s d yn am i c factor (see 5. 3. 3);

H

i s l oad d i stri bu ti on factor (see 5. 3. 2).

s

= 1 . 0;

K

B

= 1 . 0;

Table 5 - Dynamic factor as a function of flank tolerance classification ANSI/AGMA ISO 1 328-1 -B1 4 Dynamic factor, Kv flank tolerance class 5

1 .1 5

4

1 .1 3

3

1 .1 1

2

1 . 09

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

11

AMERICAN NATIONAL STANDARD

5.4.1

ANSI/AGMA 601 1 -J1 4

Stress cycle factor, YN

Stress cycl e factor,

Y , i s cal cu l ated by th e l ower cu rve of fi g u re 1 8 of AN SI /AG M A 21 01 -D04, an d sh ou l d N

be based on a m i n i m u m of 40 000 h ou rs of servi ce at rated operati n g speed .

Y

N

 1 .6831 nL0.0323

(5)

wh ere

n

i s n u m ber of stress cycl es.

L

Wh en th e n u m ber of stress cycl es exceed s 1 0

10

(i . e. , speed above 41 67 rpm for 40 000 h ou rs),

Y

N

sh ou l d

be l ess th an or eq u al to 0. 80. I f l ess th an 40 000 h ou rs i s u sed for rati n g , i t sh al l be wi th th e speci fi c approval of th e pu rch aser an d sh al l be so stated al on g wi th th e rati n g .

Allowable stress numbers, σHP and σFP

5.5

Al l owabl e stress n u m bers, wh i ch are d epen d en t u pon m ateri al an d processi n g , are g i ven i n AN SI /AG M A 21 01 -D04, cl au se 1 6.

Th at cl au se al so speci fi es th e treatm en t of m om en tary overl oad con d i ti on s.

AG M A 923 ‐ B05 sh al l be u sed i n con j u n cti on wi th th i s stan d ard . I t i s to be u sed i n i ts en ti rety i n pl ace of th e m etal l u rg i cal tabl es 7, 8, 9, an d 1 0 of AN SI /AG M A 21 01 ‐ D04 (or AN SI /AG M A 2001 -D04). Fl am e h ard en ed g eari n g i s n ot approved for com pl i an ce wi th th i s stan d ard . Th ree g rad es of m ateri al h ave been establ i sh ed .

G rad e 1 m ateri al sh al l n ot be u sed for g ears rated by

th i s stan d ard . Both G rad e 2 an d G rad e 3 are h eat treated u n d er carefu l l y con trol l ed con d i ti on s. ch oi ce of m ateri al , h ard n ess an d g rad e i s l eft to th e g ear d esi g n er; h owever, val u es of

σ

HP

an d

σ

FP

Th e sh al l

be for g rad e 2 m ateri al s. Du e con si d erati on sh ou l d be g i ven to ad d i ti on al testi n g , su ch as u l trason i c or mag n eti c parti cl e i n specti on of h i g h speed g ear rotors wh i ch are su bj ect to h i g h fati g u e cycl es or h i g h stress, or both , d u ri n g operati on . Refer

to

An n ex

F

for

ad d i ti on al

m etal l u rg i cal

con si d erati on s.

For

d etai l s

on

tooth

fai l u re,

refer

to

AN SI /AG M A 1 01 0. Th e cl ean l i n ess of steel u sed for g ears con trol l ed by th i s stan d ard , speci fi cal l y n on -metal l i c i n cl u si on s i n th e raw m ateri al , sh al l be con trol l ed by AG M A 923-B05 Tabl e 2 I tem 4 Al tern ati ve A, B, or C; bu t n ot Al tern ati ve D. Th e g rai n si ze sh al l be 90% G rai n Si ze 5 an d fi n er, wi th n o g rai n coarser th an G rai n Si ze 3.

G rai n si ze

ch ecks after carbu ri zi n g may be con si d ered . Th e m i n i m u m total raw m ateri al area red u cti on rati o sh al l be ach i eved by h ot worki n g processes wh i ch en su re th rou g h -secti on worki n g .

5.6

Reverse loading

For i d l er g ears an d oth er g ears wh ere th e teeth are compl etel y reverse l oad ed on every cycl e, u se 70 percen t of th e al l owabl e ben d i n g stress n u m ber,

5.7

σ

FP ,

i n AN SI /AG M A 21 01 -D04.

Scuffing resistance

Scu ffi n g fai l u re (someti m es i n correctl y referred to as scori n g ) h as been kn own for m an y years an d i s a con cern for h i g h speed g ear u n i ts. high

sl i d i n g

vel oci ti es,

Wh en h i g h speed g ears are su bj ect to h i g h l y l oad ed con d i ti on s an d

th e l u bri can t fi l m

m ay n ot ad eq u atel y separate th e su rfaces.

d am ag e to th e tooth su rface i s referred to as “scu ffi n g ”.

Th i s l ocal i zed

Scu ffi n g wi l l exh i bi t i tsel f as a d u l l m atte or rou g h

fi n i sh u su al l y at th e extrem e en d reg i on s of th e contact path or n ear th e poi n ts of a si n g l e pai r of teeth con tact resu l ti n g i n severe ad h esi ve wear. Scu ffi n g i s n ot a fati g u e ph en om en on an d m ay occu r i n stan tan eou sl y.

Th e ri sk of scu ffi n g d am ag e vari es

wi th th e m ateri al of th e g ear, l u bri can t bei n g u sed , vi scosi ty of th e l u bri can t, su rface rou g h n ess of th e tooth fl an ks, sl i d i n g vel oci ty of th e m ati n g g ear set u n d er l oad , an d g eom etry of th e g ear teeth .

Ch an g es

i n an y or al l of th ese factors can red u ce scu ffi n g ri sk.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

12

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Further information is provided in annex B. Although annex B is not a requirement of this standard, it is recommended that this or some other method be used to check for the probability of scuffing failure. See AGMA 925-A03 for further information.

6

Lubrication

6.1

Design parameters

Proper lubrication of high speed gear units consists of: -

Selecting an appropriate lubricant;

-

Ensuring that the lubricant enters the gear mesh;

-

Providing adequate lubricant flow so that heat generated in the mesh is removed;

-

Providing adequate lubricant flow to the bearings.

There are a number of other considerations in the design of a high speed gear unit lubrication system but all are related to these three basic requirements. Failure modes that can occur due to inadequate lubrication include: scuffing, micropitting, and abrasive wear, see ANSI/AGMA 1 01 0. High speed gear units shall be designed with a pressurized lubrication supply system to provide lubrication and cooling to the gears and bearings. A normal lubricant inlet pressure of 1 to 2 bar is an industry accepted value. Special applications may require other lubricant pressures. If a gear element extends below the lubricant level in the gear casing, it is said to be dipping in the lubricant. Dipping at high speed can result in high power losses, rapid overheating, possible fire hazard, and should be avoided. The following minimum parameters should be considered to ensure that proper lubrication is provided for the gear unit: -

type of lubricant;

-

lubricant viscosity;

-

film thickness;

-

surface roughness; inlet lubricant pressure;

-

inlet lubricant temperature;

-

filtration;

-

drainage;

-

retention or settling time;

-

lubricant flow rate;

-

cooling requirements.

6.2

Choice of lubricant

The recommendations of the gear vendor should be followed, in selecting a gear lubricant, particularly when considering alternate viscosities. See Table 6 and annex I.

Table 6 - Recommended lubricants ISO viscosity grade (VG) Viscosity range mm 2/s (cSt) at 40°C Minimum viscosity index (VI)

NOTE:

32 46 68 1 00

28.8 to 35.2 41 .4 to 50.6 61 .2 to 74.8 90.0 to 1 00.0

90 90 90 90

The lubricant selected should have a pour point at least 6°C below the lowest expected ambient temperature.

Copyright American Gear Manufacturers Association ©AGMA 201 4

– All rights reserved

13

AMERICAN NATIONAL STANDARD

6.2.1

ANSI/AGMA 601 1 -J1 4

Additives

Ch an g es to th e l evel of fi l trati on sh ou l d on l y be d on e i n con su l tati on wi th both th e g ear ven d or an d l u bri can t m an u factu rers. Certai n l u bri can t ad d i ti ves, su ch as th ose i n extrem e pressu re (EP) l u bri can ts, m ay be rem oved by fi n e fi l trati on , su ch as 1 0 m i cron absol u te or fi n er; extreme pressu re l u bri can ts are n ot n orm al l y u sed i n h i g h speed u n i ts.

See 6. 3. 6.

To avoi d d epen d en cy on extrem e pressu re ad d i ti ves, u n l ess oth erwi se speci fi ed , th e g ear u n i t sh ou l d be d esi g n ed for u se wi th a l u bri can t th at fai l s I SO 1 4635-1 l oad stag e 6. Th e l u bri can t, h owever, sh al l pass I SO 1 4635-1 l oad stag e 5.

6.2.2 Viscosity Sel ecti on of an appropri ate l u bri can t vi scosi ty i s a com prom i se of factors. I n ad d i ti on , l u bri cati on system s are often ti m es i n teg rated wi th oth er d ri ve trai n eq u i pm en t wh ose vi scosi ty req u i rem en ts are d i fferen t from th e g ear u n i t. Th i s com pl i cates th e sel ecti on of th e l u bri can t. Load carryi n g capaci ty of th e l u bri can t fi l m i n creases wi th th e vi scosi ty of th e l u bri can t. Th erefore, a h i g h er vi scosi ty i s preferred at th e g ear m esh . Devel opm en t of an ad eq u ate el astoh yd rod yn am i c l u bri can t fi l m th i ckn ess an d red u cti on i n tooth rou g h n ess are of pri m ary i m portan ce to th e l i fe of th e g earset. Refer to AN SI /AG M A 925-A03 for referen ces on l u bri can t fi l m .

eval u ati n g

l u bri can t properti es for th e d evel opm en t of a

H owever, i n h i g h speed g ear u n i ts, parti cu l arl y th ose wi th h i g h beari n g l oad s an d h i g h

j ou rn al vel oci ti es,

h eat created i n th e beari n g s i s con si d erabl e. H ere,

th e vi scosi ty n eed s to be l ow

en ou g h to perm i t ad eq u ate cool i n g of th e beari n g s. An n ex I g i ves g u i d el i n es for l u bri can t sel ecti on i n th e form of tabl es based on operati n g tem peratu re an d vel oci ti es.

Refer to cl au se 4 of AN SI /AG M A 9005-E02 for l u bri can t cl assi fi cati on s an d performan ce

req u i remen ts.

6.2.3 Synthetic lubricants Syn th eti c

l u bri can ts

tem peratu re

are

m ay

i n vol ved .

be

ad van tag eou s

Th ere

are

m an y

in

som e

types

of

appl i cati on s, syn th eti c

especi al l y

l u bri can ts,

an d

wh ere some

extrem es h ave

of

d i sti n ct

d i sad van tag es. Th e g ear ven d or sh ou l d be con su l ted before u si n g an y syn th eti c l u bri can t.

6.3 Lubrication considerations 6.3.1 Ambient temperature Th e n ormal am bi en t temperatu re ran g e for h i g h speed g ear u n i t operati on i s from -1 0° C to 55° C. Th e ven d or sh ou l d be i n form ed wh at th e am bi en t tem peratu re wi l l be, or i f a l arg e rad i an t h eat sou rce i s l ocated n ear th e g ear u n i t. Fu rth erm ore, i f l ow am bi en t tem peratu re cau ses th e su m p tem peratu re to d rop bel ow 20° C at start-u p, th e g ear ven d or sh ou l d be ad vi sed . Speci al proced u res or eq u i pm en t, su ch as h eaters, m ay be req u i red to en su re ad eq u ate l u bri cati on .

6.3.2 Environment I f a g ear u n i t i s to be operated i n an extrem el y h u m i d , sal t water, ch em i cal , or d u st l ad en atm osph ere, th e g ear ven d or sh al l

be

ad vi sed .

Wh en

so

ad vi sed ,

speci al

care

sh al l

be

taken

to

preven t

l u bri can t

con tam i n ati on .

6.3.3 Temperature control Th e l u bri can t tem peratu re con trol system sh al l be d esi g n ed to m ai n tai n a l u bri can t i n l et tem peratu re wi th i n d esi g n l i m i ts at an y expected ambi en t tem peratu re or operati n g con d i ti on . Desi g n i n l et tem peratu re m ay vary, bu t 50° C i s a g en eral l y accepted val u e. Lu bri can t tem peratu re ri se th rou g h th e g ear u n i t sh ou l d be l i m i ted to 30° C. Speci al operati n g con d i ti on s, su ch as h i g h pi tch l i n e vel oci ty, h i g h i n l et l u bri can t tem peratu re, an d h i g h am bi en t tem peratu re m ay resu l t i n h i g h er operati n g tem peratu res.

6.3.4 Gear element cooling and lubrication Th e si ze an d l ocati on of th e spray n ozzl es i s cri ti cal to th e cool i n g an d proper l u bri cati on of th e g ear m esh .

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

14

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Spray n ozzl es m ay be posi ti on ed to su ppl y l u br i can t at ei th er th e i n -m esh , ou t-m esh , or both si d es of th e g ear mesh (or at oth er poi n ts) at th e d i screti on of th e ven d or. I n oi l l u bri cated systems, th e amou n t of oi l su ppl i ed to th e g ear m esh d epen d s on th e h eat g en erati on rate.

Th e am ou n t of oi l req u i red i n th e form ati on of an oi l fi l m i s m i n i scu l e com pared to th at req u i red for

cool i n g .

M ost h i g h speed g ear l u bri cati on systems are d esi g n ed to h an d l e th e h i g h est h eat l oad an d

h ave excess capaci ty at al l oth er operati n g con d i ti on s.

H eat g en erati on i n g ears an d beari n g s can be

esti m ated by vari ou s tech n i q u es su ch as AG M A I SO 1 41 79-1 .

Typi cal l y, con vecti on an d rad i ati on are

i g n ored su ch th at th e en ti re h eat l oad i s to be tran sferred to th e cool i n g oi l by con d u cti on an d th en rem oved from th e system wi th a separate oi l cool er.

Kn owi n g th e h eat l oad , th e l u bri can t ch aracteri sti cs,

an d th e al l owabl e temperatu re ri se, th e req u i red oi l fl ow rate to cool th e g ear m esh can be cal cu l ated . Th i s cal cu l ati on i s l i m i ted to th e req u i red oi l fl ow to cool th e m esh ; n o accom m od ati on s are mad e for an ci l l ary com pon en ts su ch as beari n g s, seal s, etc.

M



Hg

ch Tout  Tin

(6)



wh ere

M

i s l u bri can t fl ow rate for h eat rem oval , kg /m i n ;

Hg

i s h eat g en erated at d esi g n poi n t, kJ /m i n ;

ch

i s l u bri can t speci fi c h eat at ( Tou t

Tou t

i s averag e oi l ou t tem peratu re, ° C;

Ti n

i s averag e oi l i n tem peratu re, ° C.

+T

i n )/2,

kJ /kg C° ;

6.3.5 Lubricant sump Th e l u bri can t reservoi r may be i n th e bottom of th e g ear case (wet su mp) or i n a separate tan k (d ry su m p). I n ei th er case, th e system sh ou l d be si zed , ven ted , an d baffl ed to ad eq u atel y d e-aerate th e l u bri can t an d con trol foam i n g . I n d ry su m p appl i cati on s, th e extern al d rai n ag e system sh al l be ad eq u atel y si zed , sl oped an d ven ted to avoi d resi d u al l u bri can t bu i l d u p i n th e g ear case. Drai n vel oci ti es m ay vary, bu t 0. 3 m eters per secon d i n a h al f fu l l open i n g i s a g en eral l y accepted m axi m u m val u e.

6.3.6 Filtration I t i s very i m portan t to con ti n u ou sl y rem ove con tam i n ati on parti cl es from th e oi l system wi th an appropri ate fi l ter u pstream of th e g earbox. I t i s g ood practi ce to l ocate th e fi l ter as n ear as possi bl e to th e g ear u n i t l u bri can t i n l et.

Th e

fi l ter sh al l

be

25

m i cron

absol u te

or fi n er.

Fi l trati on

to

10

m i cron s

absol u te

is

recom m en d ed wh en l i g h t tu rbi n e l u bri can ts, e. g . I SO VG 32, are u sed , parti cu l arl y for h i g h er operati n g tem peratu res. I SO 4406 m ay be u sed as a m ore compl ete speci fi cati on of th e oi l cl ean l i n ess req u i red . An I SO 4406: 1 999 cl ean l i n ess l evel of 1 7/1 5/1 2 i s recom m en d ed i f th ere i s n o oth er recom m en d ati on from th e g ear ven d or. Lu bri cati on system s sh al l n ot be d esi g n ed wi th th e abi l i ty to bypass oi l arou n d th e fi l ter. A d u pl ex fi l ter i s recom m en d ed to faci l i tate cl ean i n g of th e fi l ter wh en th e u n i t can n ot be con ven i en tl y sh u t d own for fi l ter ch an g e.

A m ech an i sm to i n d i cate th e cl ean l i n ess of th e fi l ter i s al so recom m en d ed .

System s th at take a porti on of th e fi l tered l u bri can t an d fu rth er cl ean i t are acceptabl e.

I t h as been fou n d

th at rem ovi n g very fi n e parti cl es can g reatl y exten d l u bri can t l i fe. I n ad d i ti on to th e fi l ter, a screen on th e su cti on si d e may be u sed to protect th e pu m p. Th i s screen sh ou l d h ave a coarse m esh to avoi d fl ow restri cti on .

CAUTION: Lu bri can ts sh ou l d n ot be fi l tered th rou g h fu l l er’ s earth or oth er types of fi l ters wh i ch cou l d rem ove th e ad d i ti ves of th e ori g i n al form u l ati on .

6.3.7 Drain lines Th e d rai n l i n e con fi g u rati on sh al l be i n accord an ce wi th th e g ear ven d or's recom m en d ati on s. Drai n l i n es sh ou l d be si zed so th ey are n o more th an h al f fu l l . Th e l i n es sh ou l d sl ope d own at a m i n i m u m of 20 m i l l i m eters per m eter an d h ave a m i n i mu m n u m ber of ben d s an d el bows.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

15

AMERICAN NATIONAL STANDARD

6.4

ANSI/AGMA 601 1 -J1 4

Lubricant maintenance

Th e l u bri can t sh ou l d be fi l tered an d tested , or ch an g ed peri od i cal l y, to assu re th at ad eq u ate l u bri can t properti es are m ai n tai n ed . Pri or to i n i ti al start-u p of th e g ear u n i t, th e l u bri cati on system sh ou l d be th orou g h l y cl ean ed an d fl u sh ed . I t i s recom men d ed th at th e i n i ti al l u bri can t be ch an g ed or tested after 500 h ou rs of operati on .

6.4.1

Change interval

U n l ess th e ven d or recom men d s d i fferen t i n terval s, u n d er n orm al operati n g con d i ti on s su bseq u en t ch an g e or test i n terval s sh ou l d be 2500 operati n g h ou rs, or 6 m on th s, wh i ch ever occu rs fi rst.

Exten d ed ch an g e

peri od s may be establ i sh ed th rou g h peri od i c testi n g of l u bri can ts. Wi th peri od i c l u bri can t testi n g an d con d i ti on i n g , i t i s n ot u n com m on to operate l u bri cati on systems wi th ou t l u bri can t ch an g es for th e l i fe of th e g ear d ri ve.

6.4.2 Water contamination Wh ere operati n g con d i ti on s resu l t i n water col l ecti n g i n th e l u bri cati on system , th e l u bri can t sh ou l d be processed ,

or

ch an g ed

as

req u i red ,

to

keep

water

con ten t

bel ow

th e

l u bri can t

m an u factu rer's

recom m en d ati on . Fai l u re to con trol m oi stu re m ay resu l t i n d am ag e to th e g ear u n i t. Som e l u bri can ts are h yg roscopi c (absorb water) an d m ay n eed speci al con si d erati on to el i m i n ate or con trol th e water con ten t an d total aci d n u m ber.

7

Vibration and sound

7.1

Vibration analysis

Th e rati n g eq u ati on s u sed by th i s stan d ard assu m e sm ooth operati on of th e rotors. Vi brati on of an y com pon en t of a g ear u n i t can resu l t i n ad d i ti on al d yn am i c l oad s bei n g su peri m posed on th e n orm al operati n g

l oad s.

Vi brati on

of

su ffi ci en t

am pl i tu d e

can

resu l t

in

i m pact

l oad i n g

of

th e

g ear

teeth ,

i n terferen ce i n th e g ear mesh , or d am ag e to com pon en ts at cl ose cl earan ce l ocati on s i n th e g ear u n i t. Th e types of vi brati on th at are g en eral l y of con cern for h i g h speed g ear u n i ts are th e torsi on al , l ateral an d axi al m od es of th e rotati n g el em en ts, si n ce th ese can h ave a d i rect i n fl u en ce on th e tooth l oad . G en eral l y h owever, on l y th e l ateral an d torsi on al d eg rees of freed om are revi ewed an al yti cal l y d u ri n g d esi g n .

7.2

Lateral critical speeds

Lateral vi brati on i s th at for wh i ch rel ati ve d i spl acem en ts of th e rotor take pl ace i n pl an es tran sverse to th e axi s of rotati on . Lateral cri ti cal speed s correspon d to reson an t freq u en ci es of th e com bi n ed rotor, beari n g an d su pport system . Th e basi c i d en ti fi cati on of cri ti cal speed s i s mad e from th e n atu ral freq u en ci es of th e system an d th e forci n g ph en om en a. I f th e freq u en cy of an y h arm on i c com pon en t of a peri od i c forci n g ph en om en on i s eq u al to, or approxi m ates th e n atu ral freq uen cy of an y m od e of rotor vi brati on , a con d i ti on of reson an ce m ay exi st. I f reson an ce exi sts, th e speed at wh i ch th e peak respon se occu rs i s cal l ed a cri ti cal speed . For rotors su pported by fl u i d fi l m beari n g s, th e speed or freq u en cy at wh i ch th ese occu r wi l l vary wi th th e tran sm i tted l oad , pri m ari l y as a resu l t of th e ch an g e i n th e sti ffn ess of th e beari n g l u bri can t fi l m . Cri ti cal

speed s are n ormal l y d eterm i n ed

u si n g

a rotor respon se an al ysi s an d

are con si d ered

to be

acceptabl e i f: (a) th e separati on m arg i n i s g reater th an 20 percen t; or (b) th e vi brati on l evel s are wi th i n th e speci fi ed l i m i t an d th e am pl i fi cati on factor i s l ess th an 2. 5 (see 7. 2. 5). I t i s i m portan t to con si d er sl ow rol l , startu p, an d sh u td own of th e eq u i pmen t as th e rotati n g el em en ts pass th rou g h th ei r cri ti cal speed s. I n som e cases a si mpl e u n d am ped l ateral cri ti cal speed an al ysi s m ay be su ffi ci en t for d esi g n .

I f th i s

m eth od i s to be th e sol e cri teri on for d eterm i n i n g th e fi tn ess of a rotor wi th i ts su pport system , i t sh ou l d be based u pon si g n i fi can t experi en ce i n th e d esi g n of h i g h speed g ear d ri ves em pl oyi n g th i s m eth od . Th e resu l ts are n orm al l y presen ted

as a m ap of u n d am ped

d eterm i n ed for vari ou s con d i ti on s of tran sm i tted l oad .

n atu ral freq u en ci es versu s su pport sti ffn ess

Th e m ap i s u sed to i d en ti fy poten ti al cri ti cal speed s

by l ocati n g th e i n tersecti on of th e pri n ci pal beari n g su pport sti ffn ess val u es wi th th e freq u en cy cu rves for a g i ven m od e sh ape. I t sh ou l d be n oted th at th e response freq u en cy of th e rotor m ay be si g n i fi can tl y d i fferen t wh en d am pi n g i s con si d ered .

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

16

AMERICAN NATIONAL STANDARD

7.2.1

ANSI/AGMA 601 1 -J1 4

Rotor response analysis

A rotor u n bal an ce respon se an al ysi s i s u sed to pred i ct th e d am ped respon se of th e rotor to vari ou s com bi n ati on s

of resi d u al

u n bal an ce

to

i d en ti fy

cri ti cal

speed s.

Th e

cri ti cal

speed s

of a

g ear rotor

d eterm i n ed from th e rotor respon se an al ysi s sh ou l d al so be veri fi ed by sh op an d fi el d test d ata. Th e an al ysi s sh ou l d con si d er th e fol l owi n g param etri c vari ati on s i n ord er to en su re th at th e vi brati on l evel s wi l l be acceptabl e for al l expected operati n g con d i ti on s: -

U n bal an ce, g -m m

WN



m i d span u n bal an ce eq u al to 6350



overh u n g m ass u n bal an ce eq u al to 63 500



ou t-of-ph ase u n bal an ce eq u al to 63 500

r/

m c;

W N W N cpl /

cpl /

m c;

mc

at cou pl i n g , an d eq u al to 31 75

WN r/

mc

at th e

fu rth erm ost m ass stati on on th e g ear tooth porti on of th e g ear wh ere

N W W

mc r

cpl

-

-

-

i s m axi m u m con ti n u ou s speed of rotor, rpm ;

i s total wei g h t of th e rotor, kg ; i s h al f wei g h t of th e cou pl i n g an d spacer, kg .

G ear l oad i n g



u n l oad ed , or m i n i m u m l oad , or both ;



50 percen t l oad , i f g reater th an m i n i m u m l oad ;



75 percen t l oad ;



1 00 percen t l oad .

Beari n g cl earan ces



m i n i mu m cl earan ce an d m axi m u m prel oad , i f appl i cabl e;



m axi m u m cl earan ce an d mi n i m u m prel oad , i f appl i cabl e.

Speed ran g e from zero to 1 30 percen t of m axi m u m con ti n u ou s speed .

7.2.2 Mode shape Each reson an t freq u en cy h as an associ ated mod e sh ape. Kn owi n g th e sh ape th e rotor wi l l assu m e wh en respon d i n g to a cri ti cal speed i s i m portan t i n u n d erstan d i n g th e con seq u en ces of beari n g pl acemen t an d resi d u al u n bal an ce.

For m ost h i g h speed g ear rotors,

th e si g n i fi can t m od es are th e tran sl ati on al or

bou n ci n g m od e, th e rocki n g or pi voti n g m od e an d th e fi rst ben d i n g m od e. l ocati on

typi cal l y en h an ces

d ampi n g .

High

am pl i tu d e

l ocati on s

i n d i cate

Di spl acem en t at th e beari n g pl aces

for effecti ve

bal an ce

correcti on s.

7.2.3 Analytical considerations For m ost cou pl i n g d esi g n s u sed for h i g h speed mach i n ery, th e cou pl i n g m om en ts an d sh ear forces tran sferred between rotors wi l l be m i n i mal . As a resu l t, each cou pl ed rotor can g en eral l y be con si d ered to be i sol ated an d th erefore an al yzed i n d epen d en tl y. Th e an al yses sh ou l d i n cl u d e th e fol l owi n g effects on th e cri ti cal speed s: -

for rotor wi th fl u i d fi l m beari n g s, oi l fi l m sti ffn ess an d d am pi n g for th e ran g e of beari n g d i men si on s an d tol eran ces, l oad an d speed ;

-

beari n g stru ctu re an d g ear casi n g su pport stru ctu re sti ffn ess;

-

cou pl i n g wei g h t to be su pported by each sh aft (th e wei g h t of th e cou pl i n g h u b pl u s 1 /2 th e wei g h t of th e cou pl i n g spacers). Th e cou pl i n g wei g h t sh ou l d be appl i ed at th e proper cen ter of g ravi ty rel ati ve to th e sh aft en d . Th e wei g h t an d cen ter of g ravi ty sh al l be speci fi ed by th e pu rch aser of th e cou pl i n g ;

-

poten ti al u n bal an ce of th e g ear rotor an d cou pl i n g .

7.2.4 Other forcing phenomena A forci n g ph en om en on or exci ti n g freq u en cy m ay be l ess th an , eq u al to, or g reater th an th e syn ch ron ou s freq u en cy of th e rotor. Poten ti al forci n g freq u en ci es i n cl u d e, bu t are n ot l i m i ted to th e fol l owi n g : -

u n bal an ce i n th e rotor system ;

-

cou pl i n g m i sal i g n m en t freq u en ci es;

-

l oose rotor-system com pon en t freq u en ci es;

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

17

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

-

i n tern al ru b freq u en ci es;

-

l u bri can t fi l m freq u en ci es;

-

asyn ch ron ou s wh i rl freq u en ci es;

-

g ear-m esh i n g an d si d e-ban d freq u en ci es, as wel l as oth er freq u en ci es prod u ced by i n accu raci es i n th e g en erati on of th e g ear teeth .

7.2.5 Amplification factor, AF Th e am pl i fi cati on factor,

AF,

i s a m easu re of th e rotor’ s sen si ti vi ty to u n bal an ce wh en operati n g i n th e

vi ci n i ty of a rotor-su pport system cri ti cal speed . I t i s d efi n ed as th e cri ti cal speed d i vi d ed by th e ban d wi d th of th e respon se freq u en ci es at th e h al f power poi n ts of th e respon se peak on a Bod é pl ot.

Nct Ncp  Ncm

AF 

(7)

wh ere

N N N

ct

i s rotor fi rst cri ti cal cen ter freq u en cy, rpm;

cm

i s i n i ti al (l esser) speed at 0. 707 peak am pl i tu d e (cri ti cal ), rpm ;

cp

i s fi n al (g reater) speed at 0. 707 peak am pl i tu d e (cri ti cal ), rpm .

NOTE:

A Bod é pl ot i s a g raph i cal d i spl ay of a rotor’ s syn ch ron ou s vi brati on am pl i tu d e an d ph ase an g l e versu s

rotati on al speed .

Th e respon se of a cri ti cal speed i s u su al l y con si d ered to be cri ti cal l y d am ped i f th e am pl i fi cati on factor i s l ess th an 2. 5 (see Fi g u re 1 ). Th e sh ape of th e cu rve i n Fi g u re 1 i s for i l l u strati on pu rposes on l y an d d oes n ot n ecessari l y represen t an y actu al rotor respon se pl ot. I n cases wh ere th e am pl i tu d e d oes n ot d ecrease to m ay be approxi m ated by cal cu l ati n g

AF 

N

cp

from th e “fl i p” of

N

N

cp

(0. 707 of peak),

AF

cm , or u se an oth er m eth od . See [4] .

Nct 2  Nct  Ncm 

(8)

7.2.6 Stability analysis A rotor can vi brate at freq u en ci es bel ow th e operati n g speed as a resu l t of cross-cou pl ed forces created by com pon en ts su ch as beari n g s an d seal s an d assem bl ed com pon en ts wi th sh ri n k fi ts.

A d am ped

stabi l i ty an al ysi s can be perform ed to pred i ct su bsyn ch ron ou s freq u en ci es an d th e rotor-beari n g system s sen si ti vi ty to a respon se. Th i s sen si ti vi ty i s n orm al l y expressed as th e n atu ral l og ari th m of th e rati o of two su ccessi ve respon se peaks i n free h arm on i c vi brati on .

Th i s i s referred to as th e l og ari th m i c d ecrem en t or

l og d ec. Th e val u e i s cal cu l ated d u ri n g a rotor stabi l i ty an al ysi s an d i s a m easu re of rotor system stabi l i ty. A n eg ati ve val u e i n d i cates th e system i s u n stabl e. A rotor sh ou l d h ave m i n i mu m l og d ec of +0. 1 at an y of th e d am ped ei g en val u es to be con si d ered stabl e.

Key

N N -N AF SM CRE A mc cp

ct

cm

i s m axi m u m con ti n u ou s rotor speed , rpm ; i s peak wi d th at th e h al f power poi n t; i s am pl i fi cati on factor; i s separati on m arg i n ; i s cri ti cal respon se en vel ope; i s am pl i tu d e at

N

ct.

Figure 1 - Amplification factor

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

18

AMERICAN NATIONAL STANDARD

7.3

ANSI/AGMA 601 1 -J1 4

Torsional vibration analysis

Torsi on al vi brati on i s th at for wh i ch th e d i spl acem en ts are rel ati ve rotati on s abou t th e axi s of rotati on . To be mean i n g fu l , th e torsi on al vi brati on an al ysi s sh al l con si d er th e compl ete system i n cl u d i n g pri m e m over, g ear u n i t, d ri ven eq u i pm en t an d cou pl i n g s. Dyn am i c l oad s i m posed on a g ear u n i t from torsi on al vi brati on s are th e resu l t of th e d yn am i c beh avi or of th e en ti re system an d n ot th e g ear u n i t al on e. G ear i m perfecti on s, su ch as ru n ou t, can be a si g n i fi can t sou rce of exci tati on for torsi on al vi brati on . Th e party wi th trai n respon si bi l i ty n ormal l y carri es th e respon si bi l i ty for th e torsi on al system . Th e oth er eq u i pmen t

m an u factu rers

are

u su al l y

respon si bl e

on l y

for

th e

accu racy

of

th e

m ass

el asti c

d ata

represen ti n g th e eq u i pm en t su ppl i ed . Tu n i n g of th e system i s often a sh ared respon si bi l i ty so th at d esi g n ch an g es n ecessary to affect th e trai n n atu ral freq u en ci es can be m ad e at th e l ocati on s wh ere th ey wi l l be m ost effecti ve.

7.4

Balance

Al l g ear rotati n g el em en ts sh ou l d be m u l ti pl an e d yn am i cal l y bal an ced after assem bl y of th e rotor. Rotors wi th si n g l e keys for cou pl i n g s sh ou l d be bal an ced wi th th ei r keyway fi tted wi th a fu l l y crown ed h al f-key so th at th e sh aft keyway i s fi l l ed for i ts en ti re l en g th . Th e bal an ci n g mach i n e sh al l be su i tabl y cal i brated , wi th d ocu m en tati on of th e cal i brati on avai l abl e. Th e rotati n g el em en ts sh ou l d be bal an ced to th e l evel of eq u ati on 9 or better:

Um ax 

6350 W

Nm c

(9)

wh ere

U W N

m ax

i s i n d i vi d u al j ou rn al stati c l oad i n g per pl an e, kg ; i s m axi m u m con ti n u ou s speed , rpm .

mc

7.5

i s m axi m u m am ou n t of resi d u al rotor u n bal an ce per pl an e, g -m m ;

Shaft vibration

Du ri n g th e fu n cti on al test of th e assembl ed g ear u n i t operati n g at i ts m axi m u m con ti n u ou s speed or at an y oth er speed wi th i n th e speci fi ed ran g e of operati n g speed s, th e peak to peak ampl i tu d e of vi brati on for each sh aft i n an y pl an e m easu red on th e sh aft ad j acen t an d rel ati ve to each rad i al beari n g sh al l n ot exceed th e val u e g i ven i n eq u ati on 1 0, or 50 µ m , wh i ch ever i s l ess:

A

2800

(1 0)

Nm c

wh ere

A

μ

i s th e al l owabl e am pl i tu d e of u n fi l tered vi brati on , m i crom eters ( m ) peak to peak.

7.5.1

Electrical and mechanical runout

Wh en provi si on s for sh aft n on -con tacti n g ed d y cu rren t vi brati on probes are su ppl i ed on th e g ear u n i t, el ectri cal an d mech an i cal ru n ou t sh al l be d eterm i n ed by rol l i n g th e rotor i n V-bl ocks at th e j ou rn al beari n g cen terl i n e,

or on cen ters tru e to th e beari n g j ou rn al s,

wh i l e m easu ri n g ru n ou t wi th a n on -con tacti n g

vi brati on probe an d a d i al i n d i cator. Th i s m easu rem en t wi l l be taken at th e cen terl i n e of th e probe l ocati on an d on e probe ti p d i am eter to ei th er si d e. Th e resu l ts sh ou l d be i n cl u d ed wi th th e test report.

7.5.2 Electrical/mechanical runout compensation I f th e g ear ven d or can d em on strate th at el ectri cal or m ech an i cal ru n ou t i s presen t, th e m easu red ru n ou t m ay be vectori al l y su btracted from th e vi brati on si g n al m easu red d u ri n g th e fu n cti on al test. H owever, i n n o case sh al l th e am ou n t su btracted exceed th e smal l est of: -

m easu red ru n ou t;

-

25 percen t of th e test l evel d eterm i n ed from 7. 5;

-

6. 4 m i crometers.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

19

AMERICAN NATIONAL STANDARD

7.6

ANSI/AGMA 601 1 -J1 4

Casing vibration

Du ri n g sh op n o-l oad test of th e assembl ed g ear d ri ve operati n g at i ts m axi m u m con ti n u ou s speed or at an y oth er speed wi th i n th e speci fi ed ran g e of operati n g speed s, casi n g vi brati on as m easu red on th e beari n g h ou si n g sh al l n ot exceed th e val u es sh own i n Tabl e 7.

7.7

Vibration measurement

Vi brati on m easu remen ts an d i n stru m en tati on sh al l be i n accord an ce wi th AN SI /AG M A 6000-B96 u n l ess oth erwi se ag reed u pon by th e pu rch aser an d ven d or.

7.8

Sound measurement

Sou n d l evel m easu rem en t an d l i m i ts sh al l be i n accord an ce wi th AN SI /AG M A 6025-D98 u n l ess oth erwi se ag reed u pon by th e pu rch aser an d ven d or

8

Inspection and testing

8.1

Static tooth contact inspection

Pri or to fu n cti on al testi n g , stati c tooth con tact ch ecks m ay be perform ed to record an d compare fi n d i n g s to th e acceptabl e l i m i ts i n accord an ce wi th AG M A 91 5-1 -A02 cl au se 1 0. G ear tooth con tact pattern s i n d i cate h ow wel l a g ear set i s al i g n ed an d h el p d eterm i n e operati on al com pati bi l i ty of a pi n i on an d g ear.

Stati c n o-l oad con tact pattern s m ay be i n spected i n a rol l stan d or i n

an u n stressed g ear h ou si n g , u si n g Pru ssi an bl u e or appropri ate m arki n g com pou n d . A rol l stan d can be u sed to obtai n n ear perfect al i g n m en t of th e g ear set axes to eval u ate d evi ati on s from d esi g n ed profi l e an d h el i x. Con tact pattern s obtai n ed i n a g ear h ou si n g i n cl u d e g ear tooth d evi ati on s, g ear h ou si n g bore d evi ati on s, an d effects of beari n g cl earan ce, see an n ex J .

NOTE:

Stati c n o-l oad tooth con tact pattern s are n ot as rel i abl e as d yn am i c n o-l oad or d yn am i c part l oad con tact

pattern s for sh owi n g g ear set al i g n m en t.

Stati c n o-l oad tests d o n ot sh ow d i storti on an d m i sal i g n m en t cau sed by

l oad , speed , tem peratu re or actu al operati n g posi ti on s of th e rotors. Th erefore, stati c n o-l oad tests are u su al l y prel i m i n ary i n specti on s th at are fol l owed by d yn am i c n o-l oad or d yn am i c part or fu l l y l oad ed tests. I f th e con tact pattern s are u n acceptabl e, i t i s u su al l y n ecessary to re-i n spect th e g ear set on a g ear tooth i n specti on mach i n e to re-veri fy actu al g ear tooth d evi ati on s before d eterm i n i n g th e correcti ve acti on to be taken . Con tact pattern s are i n spected i n th e g ear h ou si n g u si n g (pre-fu n cti on al test appl i ed ) l ayou t l acq u er. Con tact pattern s obtai n ed u n d er d yn am i c n o-l oad or d yn ami c part or fu l l l oad tests sh ow th e cu m u l ati ve effects of g ear tooth d evi ati on s, g ear h ou si n g bore d evi ati on s, beari n g cl earan ces, an d d efl ecti on s d u e to l oad , speed , an d tem peratu re.

8.2

Functional testing

Each u n i t sh al l be tested at fu l l speed . practi cal .

Spare rotati n g el em en ts sh ou l d al so be tested at fu l l speed wh en

Ad d i ti on al tests m ay al so be d on e at oth er speed s or l oad s.

Th e proced u res m ay be th e

ven d or's stan d ard or on e ag reed u pon by th e ven d or an d pu rch aser. Fu n cti on al testi n g may i n cl u d e proced u res ran g i n g from parti al speed an d n o l oad spi n testi n g to fu l l speed an d fu l l power testi n g .

Fu n cti on al testi n g presen ts an opportu n i ty to eval u ate th e operati on al

i n teg ri ty of th e d esi g n an d m an u factu re of g ear d ri ves.

Fu n cti on al test proced u res provi d e a m ean s of

eval u ati n g th e en ti re g ear system for n oi se, vi brati on , l u bri cati on , g ear tooth con tact, beari n g operati n g tem peratu res, beari n g stabi l i ty, l u bri can t seal i n g , m ech an i cal effi ci en cy, i n stru m en t cal i brati on an d oth er u n i t featu res, an d m ay provi d e d ata th at paral l el s th e expected on -l i n e operati on al ch aracteri sti cs.

Frequency range

Table 7 - Casing vibration levels Velocity 1 0 Hz - 2.5 kHz Acceleration 2.5 kHz - 1 0 kHz

U n fi l tered (peak) Fi l tered com pon en t

NOTES: 1)

 

4 m m /sec

 

4 g’s

2. 5 m m /sec

Th e above vi brati on l evel s are for h ori zon tal offset g ear u n i ts on l y. Th e al l owabl e vi brati on l evel s for verti cal

offset g ears are twi ce th ose sh own i n th e tabl e. 2)

Fi l tered com pon en t m ean s an y vi brati on peak wi th i n th e freq u en cy ran g e.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

20

AMERICAN NATIONAL STANDARD

8.2.1

ANSI/AGMA 601 1 -J1 4

No load testing

Th e u n i t u n d er test i s n orm al l y d ri ven i n th e sam e rotati on al d i recti on an d wi th th e sam e i n pu t sh aft as i n th e d esi g n appl i cati on .

Th e ou tpu t sh aft wi l l h ave n o l oad appl i ed to i t.

parti al speed to overspeed .

Test speed s m ay ran g e from

Th e test d u rati on sh ou l d be at l east two h ou rs after tem peratu re stabi l i zati on .

N ote th at l on g er test ti m es h el p i d en ti fy an y l eakag e probl em s.

8.2.2 Full speed and partial load testing Th e u n i t u n d er test i s n orm al l y d ri ven i n th e sam e rotati on al d i recti on an d wi th th e sam e i n pu t sh aft as i n th e d esi g n appl i cati on . torq u e l ess th an

Th e ou tpu t sh aft wi l l be con n ected to a l oad i n g d evi ce wh i ch appl i es a resi sti n g

th e d esi g n

fu l l

l oad

torq u e.

Th e test d u rati on

sh ou l d

be at l east two h ou rs after

tem peratu re stabi l i zati on . N ote th at l on g er test ti m es h el p i d en ti fy an y l u bri can t l eakag e probl em s.

8.2.3 Full speed and full load testing Th e u n i t u n d er test i s d ri ven i n th e sam e rotati on al d i recti on an d wi th th e sam e i n pu t sh aft as i n th e d esi g n appl i cati on . Fu l l l oad testi n g d u rati on i s u su al l y at l east fou r h ou rs after tem peratu re stabi l i zati on .

8.2.3.1 Straight through testing Wh en th ere i s su ffi ci en t power capaci ty i n th e test stan d , testi n g m ay be d on e si m pl y by con n ecti n g a m otor to on e sh aft of th e g earbox an d a l oad i n g d evi ce to th e oth er sh aft, see 8. 2. 2.

8.2.3.2 Back-to-back locked torque testing. Fu l l l oad testi n g of u n i ts wi th h i g h power rati n g s m ay req u i re back-to-back l ocked torq u e testi n g .

I n th i s

proced u re two i d en ti cal rati o u n i ts are sh aft cou pl ed tog eth er, i n pu t to i n pu t an d ou tpu t to ou tpu t.

Fu l l

operati on al torq u e i s appl i ed by d i sen g ag i n g on e of th e sh aft cou pl i n g s, rotati n g th e sh afts rel ati ve to on e an oth er u n ti l th e proper torq u e i s ach i eved , th en en g ag i n g th e sh aft cou pl i n g . th e torq u e may al so be u sed .

Speci al d evi ces to appl y

Th e u n i t sh afts are th en rotated at fu l l speed .

Wh en perform i n g back-to-back l ocked torq u e testi n g th e fol l owi n g ri sks sh ou l d be con si d ered : -

Beari n g s wi th fu l l l oad appl i ed at th e stati c con d i ti on wi l l start wi th fu l l l oad an d n o h yd rod yn am i c l u bri can t fi l m u n ti l “som e” rotati on al speed i s reach ed ;

-

G ear an d pi n i on teeth wi th fu l l l oad appl i ed at th e stati c con d i ti on wi l l start wi th fu l l l oad an d n o l u bri can t fi l m to separate th e teeth u n ti l “som e” rotati on al speed i s reach ed .

Scu ffi n g m ay occu r;

speci al proced u res su ch as coati n g of th e g ear teeth wi th an EP l u bri can t m ay be req u i red (th i s probl em m ay be avoi d ed i f th e m eth od of torq u e appl i cati on al l ows start u p at l ow torq u e); -

Sl ave u n i t beari n g l oad s are i n th e opposi te d i recti on , stu b sh afts u sed to compl ete th e torq u e path m ay h ave to be rem oved , an d i f th e g ear el em en ts of th e sl ave u n i t are n ot fl i pped en d for en d , th ey wi l l be l oad ed on th e fl an ks th at are n ot n orm al l y l oad ed .

Th erefore th e sl ave u n i t, an d often al so th e

tested u n i t, wi l l h ave to be m od i fi ed after th e test; -

For pu rposes of th i s test th e sl ave u n i t m ay req u i re a h el i x an d profi l e m od i fi cati on su i tabl e for l oad i n g i n th e testi n g m od e.

Wh en th e h el i ces are m od i fi ed speci fi cal l y for test, th en after back-to-back

testi n g th e sl ave g ears m ay req u i re fi n al m od i fi cati on su i tabl e for th e con tract appl i cati on . an d pu rch aser sh al l ag ree on th e exten t of th i s work.

Th e ven d or

At th e con cl u si on of back-to-back tests, th e

sl ave u n i t wi l l req u i re a test of i ts own , si n ce th e back-to-back con fi g u rati on can n ot be d u pl i cated for th at pu rpose.

Th e ven d or an d pu rch aser sh al l ag ree on th e test to be perform ed .

8.2.3.3 Back-to-back regenerative testing Fu l l l oad testi n g of u n i ts wi th h i g h power rati n g s m ay al so be d on e wi th back-to-back reg en erati ve testi n g . I n th i s proced u re a motor i s con n ected to th e fi rst of two i d en ti cal rati o u n i ts th at are sh aft cou pl ed tog eth er, ou tpu t to ou tpu t, an d th e secon d u n i t i s cou pl ed to a g en erator.

Th i s test i s very si m i l ar to a

back-to-back l ocked torq u e test, wi th th e sam e ri sks an d req u i remen ts, except th at th e tran sm i tted power can be easi l y vari ed an d exten d ed sh afts g en eral l y are n ot n eed ed .

Th e power from th e g en erator i s

u sed to offset th e power req u i red by th e m otor, so the n et power u sed i s si m i l ar to th at of a back-to-back l ocked torq u e test.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

21

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

8.2.4 Special testing In

th e case of very h i g h

becom e

i m practi cal .

In

rotati on al su ch

speed s or m u l ti pl e i n pu t/ou tpu t sh afts,

cases,

speci al

test proced u res

speci fi c

to

con ven ti on al th e

testi n g

appl i cati on

may

sh ou l d

be

d evel oped between th e ven d or an d pu rch aser.

8.2.5 Power loss testing Wh en testi n g for power l oss i n a h i g h speed g ear u n i t, on e m eth od i s to measu re th e h eat removed by th e l u bri can t fl owi n g th rou g h th e g ear u n i t. Lu bri can t fl ow rate

an d

Con vecti on an d rad i an t l osses are n ot i n cl u d ed i n th i s m eth od .

l u bri can t i n l et an d

ou tl et tem peratu res

are

m easu red .

Power l oss

is

th en

cal cu l ated u si n g :

P Q L

LU BE

c T

(1 1 )

p

wh ere

P Q ΔT c L

i s power l oss, kW;

LU BE

i s l u bri can t fl ow, kg /sec; i s ch an g e i n l u bri can t tem peratu re from i n l et to ou tl et, C° ; i s speci fi c h eat of th e l u bri can t, kJ /kg C° .

p

Aerati on of th e l u bri can t may resu l t i n th e i n d i cated fl ow rate bei n g h i g h er th an th e actu al mass fl ow, so th e i n d i cated fl ow m ay n eed to be ad j u sted to a l ower val u e. Accu racy of th e power l oss cal cu l ati on m ay be i m proved i f al l oth er h eat tran sfer to or from th e g ear u n i t i s properl y accou n ted for. Oth er meth od s of m easu ri n g power l oss m ay be u sed , su ch as th e d i fferen ce i n th e power i n an d ou t as m easu red wi th torq u e meters, i f ag reed to by th e pu rch aser an d ven d or.

8.3

Post functional inspections

Post

fu n cti on al

i n specti on

teard own

al l ows

i n specti on

for fi n al

i n specti on

is

n ot

req u i red

of rotors,

by

beari n g s

th i s

stan d ard ,

an d

seal s

bu t

pri or to

is

recomm en d ed .

fi n al

assembl y.

Th i s

I n tern al

com pon en ts m ay al so h ave proper preservati on appl i ed fol l owi n g th i s i n specti on i f n o fu rth er testi n g i s to be d on e. Du ri n g post fu n cti on al i n specti on , record th e resu l ts of th e d yn am i c tooth con tact pattern ch ecks, an d com pare th e fi n d i n g s to th e ven d or’ s req u i rem en ts.

9

Vendor and purchaser data exchange

9.1

Rationale for data requirements

I n ord er to prom ote con si sten cy an d red u ce errors, recom m en d ed i n formati on to be fu rn i sh ed to th e ven d or an d

d ata

provi d ed

by th e

ven d or i s

speci fi ed

in

th i s

cl au se.

A d etai l

of th e

sch ed u l e

for

tran sm i ssi on of d rawi n g s, cu rves an d d ata sh ou l d be ag reed to at th e ti m e of th e proposal or ord er. Th e pu rch aser sh ou l d prom ptl y revi ew th e ven d or's d ata wh en recei ved ; h owever, th i s revi ew d oes n ot con sti tu te perm i ssi on to d evi ate from an y req u i rem en ts i n th e pu rch ase ord er u n l ess speci fi cal l y ag reed u pon i n wri ti n g .

After th e d ata h as fi n al approval , th e ven d or sh ou l d fu rn i sh certi fi ed copi es i n th e q u an ti ty

speci fi ed . A compl ete l i st of al l ven d or d ata sh ou l d be i n cl u d ed wi th th e fi rst i ssu e of m aj or d rawi n g s.

Th i s l i st

con tai n s ti tl es, d rawi n g n u m bers, an d a sch ed u l e for tran sm i ssi on of al l d ata th e ven d or wi l l fu rn i sh . I n q u i ry d ocu m en ts sh ou l d be revi sed to refl ect an y su bseq u en t ch an g es.

Th ese ch an g es wi l l resu l t i n th e

pu rch aser's i ssu e of com pl eted , corrected d ata sh eets as part of th e ord er speci fi cati on s.

9.2

Document identification

Tran sm i ttal

(cover)

l etter

ti tl e

bl ocks

or

ti tl e

pag es

sh ou l d

con tai n

th e

fol l owi n g

i n form ati on ,

wh en

avai l abl e: -

pu rch aser/u ser's corporate n am e;

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

22

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

-

j ob/proj ect n am e or i d en ti fi cati on ;

-

eq u i pmen t i tem n u m ber;

-

i n q u i ry or pu rch ase ord er n u m ber;

-

an y oth er i d en ti fi cati on speci fi ed i n th e i n q u i ry or pu rch ase ord er;

-

ven d or's i d en ti fyi n g proposal n u m ber, sh op ord er n u m ber, seri al n u m ber, or oth er referen ce req u i red to com pl etel y i d en ti fy retu rn correspon d en ce.

9.3

Data provided by purchaser

To al l ow th e g ear u n i t to be properl y sel ected or d esi g n ed , th e ven d or n eed s ad eq u ate i n form ati on from th e pu rch aser. -

Th e fol l owi n g i s a g u i d e to d ata th at sh ou l d be sen t al on g wi th a req u est for q u otati on :

a d ata sh eet i s provi d ed i n an n ex H .

Al l of th e d ata on th e l eft h an d si d e of th at form sh ou l d be

i n cl u d ed i n th e req u est for proposal ; -

scope of su ppl y;

-

i n form ati on on th e cou pl i n g s th at wi l l be u sed ;

-

testi n g req u i rem en ts;

-

m easu rem en t u n i ts to be u sed i n d rawi n g s an d oth er com mu n i cati on s (SI or U . S. cu stom ary);

-

l i st of appl i cabl e stan d ard s an d speci fi cati on s;

-

copi es of an y appl i cabl e pu rch aser speci fi cati on s;

-

an y oth er speci al

req u i rem en ts,

su ch

as pai n ti n g ,

sh i ppi n g ,

storag e or en vi ron m en tal

protecti on

req u i remen ts.

9.4

Proposal data

Th e fol l owi n g i s a g u i d e to proposal d ata th at sh ou l d be fu rn i sh ed by th e ven d or: -

g en eral arran g em en t or ou tl i n e d rawi n g for each g ear u n i t sh owi n g overal l d i men si on s;

-

pu rch aser's d ata sh eets, wi th com pl eted ven d or's i n form ati on en tered th ereon an d l i teratu re to fu l l y d escri be d etai l s of th e offeri n g (a su g g ested d ata sh eet i s provi d ed i n an n ex H );

-

i f appl i cabl e, a l i st of req u ested excepti on s to th e speci fi cati on s;

-

sch ed u l e for sh i pmen t of th e eq u i pmen t, i n weeks after recei pt of both th e pu rch ase ord er an d al l

-

l i st of recomm en d ed start-u p spares, i n cl u d i n g an y i tem s th at th e ven d or's experi en ce i n d i cates are

approved d rawi n g s;

l i kel y to be req u i red ; -

com pl ete tabu l ati on of th e u ti l i ty req u i rem en ts, i n cl u d i n g th e req u i red fl ow rate of l u bri can t an d su ppl y pressu re, h eat l oad to be rem oved by th e l u bri can t, an d n amepl ate power rati n g (approxi m ate d ata sh al l be d efi n ed an d i d en ti fi ed as su ch );

-

d escri pti on of tests an d i n specti on proced u res, as req u i red ;

-

wh en req u ested , th e ven d or sh ou l d fu rn i sh a l i st of th e proced u res for an y speci al , or opti on al tests,

-

an y start-u p, sh u t-d own , or operati n g restri cti on s req u i red to protect th e i n teg ri ty of th e eq u i pmen t;

-

con d i ti on s an d peri od of th e ven d or's warran ty.

th at h ave been speci fi ed by th e pu rch aser or proposed by th e ven d or;

9.5

Items needing resolution

Th e fol l owi n g i tem s n orm al l y sh ou l d be resol ved after pu rch ase com m i tm en t.

Th i s m ay be d on e at a

coord i n ati on m eeti n g , preferabl y at th e ven d or's pl an t or by oth er su i tabl e m ean s of com mu n i cati on . -

pu rch ase ord er, ven d or's i n tern al ord er d etai l s an d su b-ven d or i tem s;

-

an y req u i red d ata sh eets;

-

appl i cabl e speci fi cati on s, stan d ard s, cl ari fi cati on s an d previ ou sl y ag reed u pon excepti on s;

-

Th at th e system an d al l i ts com pon en ts are i n accord an ce wi th speci fi ed stan d ard s;

-

sch ed u l es for tran sm i ttal of d ata, prod u cti on an d testi n g ;

-

q u al i ty assu ran ce prog ram , proced u res an d acceptan ce cri teri a;

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

23

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

-

i n specti on , exped i ti n g an d testi n g ;

-

sch em ati cs an d bi l l s of m ateri al (B/M s) of au xi l i ary systems;

-

ph ysi cal ori en tati on of eq u i pm en t, sh aft rotati on , pi pi n g an d au xi l i ary system s;

-

fi n al cou pl i n g sel ecti on .

9.6

Contract data

Th e fol l owi n g l i sts con tract d ata n orm al l y su ppl i ed by th e ven d or: a.

Certi fi ed d i men si on al ou tl i n e d rawi n g an d parts l i st, i n cl u d i n g th e fol l owi n g : -

si ze, rati n g an d l ocati on of al l pu rch aser's con n ecti on s;

-

approxi m ate overal l an d h an d l i n g wei g h ts;

-

overal l d i men si on s;

-

d i m en si on ed sh aft en d (s) for cou pl i n g mou n ti n g (s);

-

h ei g h t of sh aft cen terl i n e;

-

d i m en si on s of basepl ates or sol epl ates (i f fu rn i sh ed ), com pl ete wi th th e d i am eter, n u m ber an d l ocati on of bol t h ol es an d th i ckn ess of th e m etal th rou g h wh i ch bol ts pass;

-

sh aft posi ti on d i ag ram , i n cl u d i n g recom m en d ed l i m i ts d u ri n g operati on , wi th al l ch an g es i n sh aft en d posi ti on an d su pport g rowth s from an am bi en t referen ce or 1 5° C n oted ;

b.

c.

-

j ou rn al beari n g cl earan ces an d tol eran ces;

-

axi al rotor fl oat or th ru st beari n g cl earan ce, as appl i cabl e;

-

n u m ber of teeth on each g ear.

El ectri cal an d i n stru men tati on sch emati cs an d bi l l s of m ateri al s, i n cl u d i n g th e fol l owi n g : -

vi brati on warn i n g an d sh u td own l i m i ts;

-

beari n g tem peratu re warn i n g an d sh u td own l i m i ts;

-

l u bri can t temperatu re warn i n g an d sh u td own l i m i ts.

Lateral cri ti cal speed an al ysi s, wh i ch m ay i n cl u d e an y or al l of th e fol l owi n g : -

m eth od u sed ;

-

d i ag ram of beari n g an d su pport sti ffn ess an d th ei r effects on cri ti cal speed s (u n d amped l ateral cri ti cal speed m ap);

d.

-

d i ag ram of th e rotor respon se to u n bal an ce, i n cl u d i n g d am pi n g (rotor respon se an al ysi s);

-

j ou rn al beari n g sti ffn ess an d d am pi n g coeffi ci en ts;

-

d am ped stabi l i ty an al ysi s, i n cl u d i n g i d en ti fi ed ei g en val u es an d associ ated l og ari th m i c d ecremen t.

Torsi on al d ata for th e g ear u n i t an d an y sh aft cou pl i n g s su ppl i ed by th e ven d or, su ffi ci en t for a th i rd party to perform a system torsi on al an al ysi s.

e.

N am epl ates sh al l be of Seri es 300 stai n l ess steel or of n i ckel -copper al l oy (M on el or i ts eq u i val en t) attach ed by pi n s of si m i l ar m ateri al an d l ocated for easy vi si bi l i ty.

As a m i n i mu m , th e fol l owi n g d ata

sh ou l d be cl earl y stam ped on th e n am epl ate: -

ven d or's n am e;

-

si ze an d type of g ear u n i t;

-

g ear rati o;

-

seri al n u mber;

-

g ear rated power,

-

rated i n pu t speed , i n revol u ti on s per m i n u te;

P; r

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

24

AMERICAN NATIONAL STANDARD

f.

ANSI/AGMA 601 1 -J1 4

-

rated ou tpu t speed , i n revol u ti on s per m i n u te;

-

g ear servi ce factor, as d efi n ed i n th i s stan d ard ;

-

pu rch aser's i tem n u m ber;

-

n u m ber of g ear teeth ;

-

n u m ber of pi n i on teeth ;

-

d ate of m an u factu re:

m on th an d year u n i t was su ccessfu l l y tested .

Wh en th e g earbox i s n ot bi -d i recti on al , rotati on d i recti on sh al l be perm an en tl y i d en ti fi ed , su ch as wi th cast-i n or stai n l ess steel rotati on arrows.

g.

Statem en t of an y speci al protecti on req u i red for start-u p, operati on , an d peri od s of i d l en ess u n d er th e si te con d i ti on s speci fi ed

on

th e d ata sh eets.

Th e l i st sh al l

cl earl y i d en ti fy th e protecti on

to be

fu rn i sh ed by th e pu rch aser, as wel l as th at i n cl u d ed i n th e ven d or's scope of su ppl y. h.

Wh en a l u bri can t system i s su ppl i ed , a sch em ati c, certi fi ed d i m en si on al ou tl i n e d rawi n g , an d parts l i st i n cl u d i n g th e fol l owi n g :

i.

j.

9.7

-

con trol , al arm an d tri p setti n g s (pressu res an d recomm en d ed tem peratu res);

-

u ti l i ty req u i rem en ts, i n cl u d i n g el ectri cal , water an d ai r;

-

pi pe an d val ve si zes;

-

i n stru m en tati on , safety d evi ces an d con trol sch em es;

-

si ze, rati n g an d l ocati on of al l pu rch aser's con n ecti on s;

-

i n stru cti on an d operati on man u al s;

-

m axi m u m , m i n i m u m an d n orm al l i q u i d l evel s i n th e reservoi r;

-

q u an ti ty of l u bri can t req u i red to fi l l reservoi r to th e n orm al l evel .

Wh en m ech an i cal ru n n i n g test i s su ppl i ed , test reports, i n cl u d i n g th e fol l owi n g (see cl au se 8): -

vi brati on ;

-

l u bri can t fl ow an d i n l et an d ou tl et tem peratu res;

-

beari n g tem peratu res.

M an u al s wh en req u i red .

Installation manual

I n stal l ati on man u al s sh al l be provi d ed wh en speci fi ed by th e pu rch aser, an d an y speci al i n form ati on req u i red for proper i n stal l ati on d esi g n th at i s n ot on th e d rawi n g s sh al l be com pi l ed i n th i s m an u al . m an u al sh al l be forward ed at a ti m e th at i s mu tu al l y ag reed u pon i n th e ord er.

Th i s

Th e man u al sh al l con tai n

i n form ati on su ch as speci al al i g n m en t an d g rou ti n g proced u res, u ti l i ty speci fi cati on s (i n cl u d i n g q u an ti ti es), an d al l oth er n ecessary i n stal l ati on d esi g n d ata,

i n cl u d i n g d rawi n g s an d d ata speci fi ed i n 9. 6.

Th e

m an u al sh al l al so i n cl u d e sketch es th at sh ow th e l ocati on of th e cen ter of g ravi ty an d ri g g i n g provi si on s, to perm i t rem oval of th e top h al f of th e casi n g , rotors, an d su bassem bl i es th at h ave a m ass (wei g h t) g reater th an 1 40 ki l og rams.

9.8

Operation, maintenance and technical manuals

Th e ven d or sh al l provi d e su ffi ci en t wri tten i n stru cti on s an d a cross-referen ced l i st of al l d rawi n g s to en abl e th e pu rch aser to correctl y operate an d m ai n tai n al l th e eq u i pmen t ord ered .

Th i s i n form ati on

sh ou l d be com pi l ed i n a m an u al or m an u al s wi th a cover sh eet con tai n i n g al l referen ce-i d en ti fyi n g d ata speci fi ed i n 9. 2, an i n d ex sh eet con tai n i n g secti on ti tl es, an d a com pl ete l i st of referen ced an d en cl osed d rawi n g s by ti tl e an d d rawi n g n u m ber. g en eri c m an u al i s n ot acceptabl e. i n th e ord er.

Th e m an u al sh al l be prepared for th e speci fi ed i n stal l ati on ; a

Th i s m an u al sh al l be forward ed at a ti m e th at i s m u tu al l y ag reed u pon

Th i s m an u al sh al l con tai n a secti on th at provi d es speci al i n stru cti on s for operati on at

speci fi ed extrem e en vi ron m en tal con d i ti on s, su ch as tem peratu res.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

25

AMERICAN NATIONAL STANDARD

9.9

ANSI/AGMA 601 1 -J1 4

Recommended spares

When the vendor submits a complete list of spare parts, the list should include spare parts for all equipment and accessories supplied. The vendor should forward the list to the purchaser promptly after receipt of the reviewed drawings and in time to permit order and delivery of the parts before field start-up.

9.1 0 Special tools A list of special tools required for maintenance shall be furnished.

Copyright American Gear Manufacturers Association ©AGMA 201 4

– All rights reserved

26

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Annex A Service factors [Th e foreword ,

footn otes an d

an n exes,

i f an y,

con stru ed as a part of AN SI /AG M A 601 1 -J 1 4,

A. 1

are provi d ed

for i n form ati on al

pu rposes on l y an d

Specification for High Speed Helical Gear Units. ]

sh ou l d

n ot be

Purpose

Th i s an n ex provi d es d etai l ed i n stru cti on s for th e d eterm i n ati on an d u se of servi ce factors for en cl osed h i g h speed h el i cal g ear u n i ts as d escri bed i n AN SI /AG M A 601 1 -J 1 4. A. 2

Determination of service factors

Th e d eterm i n ati on of servi ce factor i s based on th e eq u i pmen t ch aracteri sti c overl oad of th e g ear u n i t as a resu l t of operati on , d esi red rel i abi l i ty of th e g ear u n i t d u ri n g i ts d esi g n l i fe, an d l en g th of ti m e th at i s con si d ered th e d esi g n l i fe.

I t rel i es h eavi l y on experi en ce acq u i red i n each speci fi c appl i cati on .

A broad

expl an ati on of th e factors i n vol ved are: -

Th e cau ses of servi ce overl oad s are broken i n to th ree broad categ ori es:

th ose prod u ced by th e

pri m e

resu l ti n g

m over,

th ose

prod u ced

by

th e

d ri ven

eq u i pm en t,

an d

th ose

from

system

con si d erati on s u n i q u e to th e eq u i pm en t trai n ; -

Th e rel i abi l i ty of a g eared system d epen d s on m an y factors both i n tern al to th e g ear u n i t i tsel f an d extern al to th e u n i t.

I n creases i n servi ce factor to i n fl u en ce rel i abi l i ty n orm al l y take i n to con si d erati on

extern al sou rces of fai l u re su ch as abu se an d u n expected operati n g con d i ti on s; -

Th e servi ce factors l i sted i n th e tabl e are for u n i ts wh ere th ere i s proper m ai n ten an ce of th e l u bri can t an d l u bri cati n g operati n g tem peratu res are kept wi th i n th e d esi g n l i m i ts.

I n stal l ati on con d i ti on s su ch

as n u m ber of startu ps an d th e startu p proced u res wi l l affect g ear l i fe, an d i n some cases m ay warran t a h i g h er servi ce factor th an l i sted i n th e tabl e; -

Th e d esi red l i fe of m ost h i g h speed en cl osed d ri ves i s u su al l y l on g er th an oth er types of en cl osed d ri ves.

At h i g h operati n g speed s th i s can tran sl ate i n to a very l arg e n u m ber of stress cycl es on th e

com pon en ts.

A.2.1 Prime mover characteristics Som e d i fferen t types of pri m e m overs are: i n tern al com bu sti on en g i n es.

el ectri c or h yd rau l i c m otors, steam or g as tu rbi n es, an d

Each of th ese pri m e movers i s d esi g n ed to prod u ce som e n om i n al power,

bu t each wi l l prod u ce th i s power wi th som e vari ati on over ti m e.

Th e vari ati on of power ou tpu t wi th ti m e

m ay be l ower or h i g h er d epen d i n g on th e pri m e m over an d al so th e way th e pri m e m over i s appl i ed i n a parti cu l ar m ach i n ery trai n , bu t an y vari ati on over n om i n al power i s an overl oad an d sh al l be con si d ered .

A.2.2 Driven equipment characteristics Dri ven eq u i pm en t can g en eral l y be d i vi d ed i n to rotary an d reci procati n g types of m ach i n es.

Rotary

m ach i n es g en eral l y h ave sm ooth er power req u i remen ts th an reci procati n g m ach i n es. I n tern al com bu sti on en g i n es m ay affect beari n g perform an ce an d l u bri cati on fi l m stabi l i ty.

Each type i s u n i q u e an d th e

eq u i pm en t ch aracteri sti cs of each n eed s to be kn own to be properl y eval u ated .

A.2.3 System conditions Th e g ear u n i t i s a part of a system wh i ch can h ave a d yn am i c respon se to varyi n g tran sm i tted power th at m ay overl oad th e g ear u n i t.

Th i s i s m ost com m on l y fou n d as torsi on al vi brati on i n th e rotati n g sh afts, bu t

can be an y vi bratory respon se to d yn am i c exci ti n g forces. tran sm i tted wi th n o am pl i fi cati on th rou g h th e g ear.

G en eral l y, overl oad s are assu m ed to be

H owever, wh en th ere i s a reson an t respon se to a

d yn am i c power overl oad , a m u ch h i g h er l oad m ay occu r at th e g ear u n i t. Th u s, th e d yn am i c overl oad s th at are cau sed by pri m e m overs an d d ri ven m ach i n es m ay be am pl i fi ed i n su ch a way as to g reatl y i n crease th ei r m ag n i tu d e at th e g ear u n i t, an d pri m ari l y at th e g ear tooth m esh . Th e n orm al (reson an ces)

rati n g of g ear u n i ts an d do

n ot

appreci abl y

th e n ormal

affect

th e

g ear

servi ce factors u sed unit

l oad .

assu m e th at th ese respon ses

Th erefore,

carefu l

system

an al ysi s

is

recom m en d ed to en su re th at n o u n expected overl oad s d u e to reson an ces are presen t.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

27

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

A.2.4 Reliability and life requirements There is a reliability factor in the power rating equations, but it deals only with the statistical nature of material testing and probability of failure for materials at a given stress level. In a gear unit there are many separate components that may fail, many modes of failure, and many factors that can contribute to those modes of failure. For this reason, quantifying factors associated with reliability and life to account for these external issues can be extremely difficult. A.3

Service factor table

Service factors have served the industry well when they have been identified by knowledgeable and experienced gear design engineers. The service factors shown in Table A.1 have been used with success in the past. These values may be used as general guidelines, but they do not eliminate the responsibility of defining any unusual system requirements that would alter the listed values.

A.3.1 General selection guidelines There is no way to list all the possible considerations that may affect selection of service factors, but the following are some guidelines. -

Induction electric motors can produce high torques on start-up. Therefore, on an application with many starts, higher service factors may be warranted;

-

Electric motors that have electric power interrupted and then re-applied before induced magnetic fields have dissipated can produce very high torques;

-

Synchronous electric motors can produce very high torsional forcing functions during start-up. This can cause very high transient torsional torques on the gear unit;

-

Generators have extremely high loads when they are out of phase with the main system, and acrossthe-line electrical shorts can produce very high torque loads. For this reason torque limiting devices or higher service factors are advisable;

-

Brakes or other decelerating devices can produce loads on the gear unit larger than the transmitted power.

The list could be much longer, but the intent here is to give a general idea of items to consider when selecting service factors.

Copyright American Gear Manufacturers Association ©AGMA 201 4

– All rights reserved

28

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Table A.1 - Service factors, CSF and KSF

Service factor, with prime mover Internal Synchronous Induction Gas or 1 steam combustion ) motors motors turbine engine

Application Bl owers Cen tri fu g al

1 .7

1 .4

1 .6

1 .7

Lobe

2. 0

1 .7

1 .7

2. 0

Com pressors Cen tri fu g al process g as, except ai r con d i ti on i n g

1 .6

1 .4

1 .6

1 .6

ai r con d i ti on i n g servi ce

1 .6

1 .2

1 .4

1 .6

ai r or pi pe l i n e servi ce

1 .7

1 .4

1 .6

1 .7

Rotary axi al fl ow - al l types

1 .7

1 .7

1 .7

1 .7

l i q u i d pi ston (N ash )

2. 0

1 .7

1 .7

2. 0

l obe - rad i al fl ow

2. 0

1 .7

1 .7

2. 0

3 or m ore cyl i n d ers

2. 0

2. 0

2. 0

2. 0

2 cyl i n d ers

2. 3

2. 0

2. 0

2. 3

1 .3

1 .1

1 .1

1 .3

Cen tri fu g al

1 .7

1 .4

1 .6

1 .7

Forced d raft

1 .7

1 .4

1 .6

1 .7

I n d u ced d raft

2. 2

1 .7

2. 0

2. 2

2. 2

1 .7

2. 0

2. 2

Base l oad or con ti n u ou s

1 .4

1 .3

1 .3

1 .4

Peak d u ty cycl e

1 .7

1 .4

1 .4

1 .7

J ord an or refi n er

--

--

1 .5

--

Paper m ach i n e - l i n e sh aft

--

--

1 .3

--

1 .7

1 .3

1 .5

1 .7

Reci procati n g

Dyn am om eter - test stan d Fan s

I n d u stri al

an d

mine

(l arg e

wi th

freq u en t starts) G en erators an d exci ters

Paper i n d u stry

Pu m ps Cen tri fu g al (al l servi ce except as l i sted bel ow) boi l er feed

--

1 .7

2. 0

--

d escal i n g (wi th su rg e tan k)

--

2. 0

2. 0

--

h ot oi l

--

1 .7

2. 0

--

pi pe l i n e

2. 0

1 .5

1 .7

2. 0

water works

2. 0

1 .5

1 .7

2. 0

3 or m ore cyl i n d ers

2. 0

2. 0

1 .7

2. 0

2 cyl i n d ers

2. 0

2. 0

2. 0

2. 0

Reci procati n g

Rotary axi al fl ow - al l types

1 .8

1 .5

1 .5

1 .8

g ear type

1 .8

1 .5

1 .5

1 .8

l i q u i d pi ston

2. 0

1 .7

1 .7

2. 0

l obe

2. 0

1 .7

1 .7

2. 0

sl i d i n g van e

1 .8

1 .5

1 .5

1 .8

Su g ar i n d u stry Can e kn i ves

1 .8

--

1 .5

1 .8

Cru sh ers

2. 0

--

1 .7

2. 0

Mills

2. 3

--

1 .7

2. 3

NOTES: 1)

G as tu rbi n es sel d om operate at fu l l d esi g n power wh i l e steam tu rbi n es often operate at or above rated power.

d esi g n con si d erati on s sh ou l d be m ad e to assu re ad eq u ate torq u e capaci ty.

Appropri ate

To accou n t for l oad vari ati on s i n excess of th e rated

l oad , h i g h er servi ce factors for steam tu rbi n e g en erator d ri ves u si n g carbu ri zed g eari n g m ay be con si d ered . 2)

Som e cen tri fu g al com pressors operate at very h i g h speed s accu m u l ati n g 1 0

10

l oad cycl es i n a sh ort peri od of ti m e.

wi th an exten d ed l i fe expectan cy, th e servi ce factor sel ecti on m ay n eed to be h i g h er th an th e val u es l i sted . en cou rag ed .

Al so fl an k tol eran ce i s an i m portan t factor.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

For u n i ts

Atten ti on to A. 2 i s

Larg er tol eran ces d i m i n i sh th e effecti ven ess of th e servi ce factor.

29

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Annex B A simplified method for verifying scuffing resistance [Th e foreword ,

footn otes an d

an n exes,

i f an y,

con stru ed as a part of AN SI /AG M A 601 1 -J 1 4,

are provi d ed

for i n form ati on al

pu rposes on l y an d

Specification for High Speed Helical Gear Units. ]

sh ou l d

n ot be

Purpose

B. 1

Th i s an n ex provi d es i n form ati on con cern i n g th e scu ffi n g (scori n g ) of h i g h speed g ear u n i ts.

Scuffing considerations

B. 2

AN SI /AG M A 601 1 -J 1 4 i s con cern ed wi th two fai l u re m od es i n g ear teeth .

Th ey are su rface pi tti n g an d

root ben d i n g fati g u e fai l u re of th e tooth m ateri al for a g i ven n u m ber of stress cycl es. kn own fai l u re type:

Th ere i s an oth er

scu ffi n g (som eti m es referred to as scori n g ).

Th e cal cu l ati on of th e scu ffi n g l oad capaci ty i s a very com pl ex probl em .

Wh i l e th i s type fai l u re h as been

kn own for m an y years an d m ath em ati cal m eth od s h ave been d evi sed to assess rel ati ve ri sk (see AG M A 925-A03), a si m pl i fi ed scu ffi n g cri teri on i s su g g ested th at i s su i tabl e for g en eral h i g h speed d esi g n work. From th e val u es of tooth l oad i n g , pi tch l i n e vel oci ty, an d vi scosi ty of th e l u bri can t, a con d en sed l oad

F (l oad ),

fu n cti on ,

i s formed , wh i ch , to assu re scu ffi n g resi stan ce, sh al l be l ess th an (or eq u al to) th e

g eom etri c fu n cti on ,

F

(g eom etri c).

Th e g eom etri c fu n cti on i s based on g ear ch aracteri sti cs su ch as

n u m ber of teeth of th e pi n i on an d g ear, cen ter d i stan ce an d g earset rati o.

F (l oad ),

l oad fu n cti on ,

d oes n ot exceed th at of th e g eom etri c fu n cti on ,

As l on g as th e val u e of th e

F (g eom etri c),

th ere i s ad eq u ate

safety ag ai n st scu ffi n g . Th erefore:

F

l oad

  F geom etric 

Load fu n cti on ,

F

 l oad 

  

(B. 1 )

F (l oad ):

w  v 0.25  46    v  C   40 

0.22

w

(B. 2)

wh ere

w v





ν40

i s speci fi c tooth l oad on th e operati n g pi tch ci rcl e, N /mm ; i s pi tch l i n e vel oci ty, m /s; 2

i s vi scosi ty of l u bri can t at 40° C, m m /s (cSt);

C = 1 . 1 0 (con servati ve val u e); C = 1 . 1 5 (n om i n al val u e); C = 1 . 20 (maxi m u m val u e). NOTE: C w w w

w

d ata.

val u es are su g g ested val u es.

Val u e of

C

w

Ven d or's own experi en ce m ay ch an g e th ese val u es wi th su pporti n g

= 1 . 20 sh ou l d on l y be u sed i f total h el i x d evi ati on m eets AN SI /AG M A I SO 1 328-1 -B1 4 fl an k

tol eran ce cl ass 3.

NOTE:

For h i g h speed g earset appl i cati on s, l u bri can t vi scosi ty m ean s l i g h t tu rbi n e oi l wi th l i ttl e or n o ad d i ti ves

based on a vi scosi ty ran g e of:

32



 40 

68.

th e l u bri can t wi th respect to scu ffi n g ten d en cy.

Th e stan d ard FZG oi l test, I SO 1 4635-1 , g i ves approxi m ati on s for See Tabl e B. 1 .

Table B.1 - Lubricant viscosities ISO viscosity grade VG Nominal viscosity at 40 ° C, mm 2/sec (cSt) VG - 22

22

VG - 32

32

VG - 46

46

VG - 68

68

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

30

AMERICAN NATIONAL STANDARD G eom etri c fu n cti on ,

F g eom etri c  

ANSI/AGMA 601 1 -J1 4

F (g eom etri c):

 50  z1  z2   a  0.5 A

Cu  

(B. 3)

wh ere

z z a A C 1

i s n u m ber of teeth of th e pi n i on ;

2

i s n u m ber of teeth of th e g ear; i s cen ter d i stan ce, m m ; i s taken from Tabl e B. 2; i s taken from Tabl e B. 2.

u

Field of application

B. 3

Th e above scu ffi n g cri teri on i s appl i cabl e to: a.

High

speed

g ears wi th

a m od i fi ed

ad d en d u m

(rack sh i ft or

x

factor) resu l ti n g

in

reason abl y

bal an ced sl i d i n g an d rol l i n g con d i ti on s between th e tooth fl an ks at th e ti p of th e pi n i on an d m ati n g g ear; b.

G ear tooth fl an k tol eran ce cl ass, per AN SI /AG M A I SO 1 328-1 -B1 4, sh ou l d be eq u al to or better th an : 5 for si n g l e pi tch d evi ati on ,

f

pt

5 for total cu m u l ati ve pi tch d evi ati on , 4 for total profi l e d evi ati on , 4 for total h el i x d evi ati on ,

Fβ

F

p



c.

Su rface rou g h n ess of tooth fl an ks after g ri n d i n g ,

d.

Basi c rack profi l e wi th : pressu re an g l e, ad d en d u m ,

Th e

Fα

worki n g

fl an ks

h

ap

α=

Ra ≤ 0. 5 μm

(20 rm s);

20 d eg

= 1 m od u l e.

of th e

pi n i on

or g ear sh ou l d

be

provi d ed

wi th

profi l e m od i fi cati on s

to

obtai n

a

trapezoi d al tooth l oad d i stri bu ti on al on g th e path of con tact. Th e worki n g fl an ks of th e pi n i on or g ear sh ou l d be provi d ed wi th h el i x (l on g i tu d i n al ) mod i fi cati on to com pen sate for ben d i n g an d torsi on al d efl ecti on s an d th erm al d eform ati on s of th e g ear rotors i n ord er to obtai n a u n i form tooth l oad d i stri bu ti on over th e en ti re rated face wi d th . Th e l u bri can t u sed sh ou l d pass I SO 1 4635-1 l oad stag e 6. B. 4

Scuffing design criteria

As stated , th ere are n o fi rm cri teri a for d esi g n i n g to preven t scu ffi n g at th i s ti m e.

H owever, i t i s h oped th at

th e u se of m eth od s su ch as th ose i n th i s an n ex an d th ose i n AGM A 925-A03 can l ead to a set of d esi g n cri teri a.

Th ere are oth er m eth od s for pred i cti n g scu ffin g an d th ere i s n o i n ten t to d en y th e val i d i ty of an y

m eth od at th i s ti m e.

α 15

Table B.2 - Values A and Cu for calculating F (geometric) A Cu at 1 ≤ u < 3 Cu at 3 ≤ u ≤ 1 0

1 7. 5

300

20

300

22. 5

250

25

250

NOTE:

u) 90 + 30 (3 - u ) 1 00 + 33. 3 (3 - u ) 95 + 28. 5 (3 - u ) 1 05 + 31 . 4 (3 - u )

350

a i s n orm al pressu re an g l e, u i s g ear rati o ( z /z ). 2

95 + 28. 6 (3 -

1 30 - 1 0 [1 1 2. 5 - (1 3 -

u)

2 0. 5

]

u) ] 1 30 - 1 0 [1 09 - (1 3 - u ) ] 1 30 - 1 0 [1 1 2. 5 - (1 3 - u ) ] 1 40 - 1 0 [1 33. 5 - (1 4 - u ) ] 1 20 - 1 0 [90 - (1 2 -

2 0. 5 2 0. 5 2 0. 5 2 0. 5

d eg rees;

1

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

31

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Annex C Systems considerations for high speed gear drives [The foreword, footnotes and annexes, if any, are provided for informational purposes only and should not be construed as a part of ANSI/AGMA 601 1 -J1 4, Specification for High Speed Helical Gear Units. ]

C.1

Purpose

The need for high mechanical reliability in geared drives can best be satisfied by a “systems approach” to the entire train of machinery including foundations, lubrication, vibration, the forces and moments associated with piping, couplings, etc. The purpose of this annex is to point out common problems that may occur, an explanation of these problems, and the possible effects. It is not the intent of this annex to present detailed methods of analyzing or solving the problem; it does not set design criteria or limits. C.2

Responsibility

A gear unit is susceptible to a variety of problems when it becomes a part of a rotating machinery system, the severity of which generally increases with speed. Even though these problems are generally beyond the gear vendor's control, they adversely affect system reliability and/or performance and may cause damage to the gear unit. The party having contractual responsibility for system performance should investigate and resolve these problems in the design stage and thereby avoid the conflicts that may develop between the component manufacturers and users. It is recommended that the party having contractual responsibility for the system analysis involving a critical service gear drive be clearly identified in the specifications, contract or purchase order. Because of the substantial cost involved in a system analysis, and in some cases the system performance, it should be emphasized that all parties supplying components to the system have a responsibility to furnish correct and accurate data so that the analysis will be meaningful. C.3

Introduction

It is not uncommon to find daily process system operating costs many times the cost of the gear unit. This downtime cost makes it desirable to avoid failure of any part in the system -- be it prime mover, coupling, gear, driven equipment, or any other component. The demands for system “mechanical reliability” can best be satisfied by a coordinated technical exchange between designer, equipment supplier, erecting engineers, and user. The various system analyses, in at least preliminary form, should precede detailed equipment purchase specifications. This sequence will permit the design to be based on more nearly correct load and operating conditions. This coordinated effort can be properly called “system engineering” and is normally performed by the design agent or his technical representative. Gear vendors may not have the expertise nor the detailed information to adequately analyze system overload. This function shall be performed by specialists under the responsibility of the systems engineer. There is no set format for communicating this data. The required information is the magnitude of overload and a description of the operational conditions under which it occurs, such as when, how long, and nature. Gear units and couplings can be adversely affected by one or more system generated problems. Failures that result from these system induced causes can be categorized under three main headings: -

those resulting from overstressing component parts, which are grouped under “overload”;

-

alignment related, such as distorted foundations or poor alignment with connected machinery;

-

those resulting primarily from a lubrication related failure.

Copyright American Gear Manufacturers Association ©AGMA 201 4

– All rights reserved

32

AMERICAN NATIONAL STANDARD C. 4

ANSI/AGMA 601 1 -J1 4

Overloads

Overl oad can be of mom en tary d u rati on , peri od i c, q u asi -stead y state, or vi bratory i n n atu re.

Depen d i n g

on i ts m ag n i tu d e an d th e n u m ber of stress cycl es accu m u l ated at overl oad , i t can be a fati g u e or a yi el d stress con si d erati on . Overl oad on a g ear d ri ve can resu l t from i n tern al or extern al cau ses.

I n tern al cau se of overl oad -- su ch

as fau l ty m an u factu ri n g (fau l ts of m an u factu re) are u su al l y fou n d by rou ti n e i n specti on s before th e g ear d ri ve i s pu t i n to servi ce.

Extern al sou rces of overl oad resu l t from th e operati on al ch aracteri sti cs of th e

system i n to wh i ch th e g ear d ri ve i s pl aced , an d are m ore com pl ex an d d i ffi cu l t to i d en ti fy. Th e g ear ven d or h as l i ttl e i f an y con trol over th e extern al i n fl u en ces th at prod u ce overl oad . en g i n eer wh o h as overal l respon si bi l i ty for perform an ce sh ou l d i n cl u d e,

Th e system

al on g wi th ou tpu t, u n i t cost,

effi ci en cy, etc. , th e i n vesti g ati on of overl oad s as th ey rel ate to poten ti al fai l u re, d own ti m e, an d system rel i abi l i ty. Th e

fol l owi n g

m ateri al

is

i n ten d ed

to

assi st

th e

system

an al yst

by

h i g h l i g h ti n g

su bj ects

for

his

con si d erati on , an d to establ i sh better com m u n i cati on between th e system an al yst an d th e g ear ven d or.

C.4.1 Estimated maximum continuous power Operati on al overl oad ch aracteri sti cs of vari ou s d ri ven eq u i pm en t vary wi th th e type of m ach i n e an d sh ou l d be con si d ered on an i n d i vi d u al basi s. Pu m p or compressor d esi g n ers, for exam pl e, can pred i ct th e power req u i rem en ts at th e d esi g n poi n t wi th fai rl y g ood accu racy.

H owever, power d u ri n g operati on resu l ts from a com bi n ati on of:

-

speci fi c g ravi ty or d en si ty of th e m ed i a bei n g pu m ped , wh i ch m ay ch an g e over ti m e;

-

carry ou t;

-

overspeed ;

-

vari ati on s i n pressu re rati o across a com pressor d u e to operati n g con d i ti on s.

Ch an g es i n speci fi c g ravi ty of th e fl u i d m ed i u m h an d l ed by a pu m p, or ch an g e i n d en si ty of th e g as h an d l ed by a com pressor, affect th e power tran sm i tted i n d i rect proporti on .

On boi l er feed pu m ps, for

exam pl e, th i s occu rren ce can be en cou n tered d u ri n g startu p, u pon m al fu n cti on of pre-h eati n g eq u i pm en t, or d u ri n g boi l er cool -d own fol l owi n g a fai l u re. In

th e case of ai r h an d l i n g

cen tri fu g al

m axi m u m am bi en t tem peratu re. d en si ty

of

ai r

vari es

wi th

com pressors,

d esi g n

power i s

u su al l y based

on

th e

n orm al

Con si d erati on sh ou l d be g i ven to col d weath er operati on si n ce th e

absol u te

tem peratu re.

Com pressors

h an d l i n g

oth er

g ases

are

en cou n tered i n process systems u n d er g reater con trol wh ere tem peratu re vari ati on s are l ess. oth er vari abl es may becom e seri ou s.

u su al l y

H owever,

I n refi n ery practi ce, for exam pl e, th e com posi ti on of th e g as can

vary wi d el y, an d i n som e process work th e i n l et pressu re m ay n ot be a fi xed val u e. Fi g u re C. 1

i l l u strates a typi cal com pressor perform an ce cu rve.

I t wi l l be n oted at 1 00% speed as th e

h ead d rops off an d fl ow i s i n creased , power i n creases to a l evel as h i g h as 1 1 5% l oad .

Th i s i n creased

power com es abou t th rou g h su ch th i n g s as i m proper esti m ati on of system perform an ce d u ri n g d esi g n stag es, al tered system req u i remen ts of exi sti n g processes, g rad u al d eteri orati on of processes, system s em pl oyi n g m u l ti pl e u n i ts wh ere sh u td own or fai l u re of on e i n creases th e req u i rem en ts on th e rem ai n i n g u n i ts, or th rou g h l eaks or fai l u res. Fi g u re C. 2 i l l u strates a si m i l ar performan ce cu rve for cen tri fu g al pu m ps. Overspeed n orm al l y on l y occu rs i n appl i cati on s wi th vari abl e speed pri m e movers.

Becau se th e power

absorpti on of th e d ri ven m ach i n e vari es approxi m atel y wi th th e th i rd power of speed , overspeed i s a l arg e con tri bu tor to overl oad .

Referri n g ag ai n to fi g u re C. 1 , th e perform an ce cu rve i n d i cates th at at 1 1 0%

speed an d 1 00% fl ow, power i s i n creased to 1 25% .

Carry ou t at th i s speed can i n crease th e power sti l l

fu rth er, to l evel s approach i n g 1 40% of d esi g n poi n t power. N orm al practi ce for a tu rbi n e d ri ven cen tri fu g al pu m p i s to set th e overspeed tri ps at 1 1 5% d esi g n speed . G overn or setti n g s are g en eral l y establ i sh ed to perm i t con ti n u ou s operati on between 1 05% an d 1 1 0% d esi g n speed .

I t sh ou l d be born e i n m i n d th at operators can an d d o reset g overn ors to avai l th em sel ves

of m axi m u m ou tpu t of th e system , reg ard l ess of th e ori g i n al setti n g s.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

33

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Figure C.1 - Typical centrifugal compressor performance curve

Figure C.2 - Typical centrifugal pump performance curve

C.4.2 Vibratory overloads An essen ti al ph ase i n th e d esi g n of a cri ti cal servi ce system of rotati n g m ach i n ery i s th e an al ysi s of th e d yn am i c (vi bratory) respon se of a system to exci tati on forces. Th e d yn am i c respon se of a system resu l ts i n ad d i ti on al l oad s i m posed u pon th e system an d rel ati ve m oti on between ad j acen t el em en ts i n th e system .

Th e vi bratory l oad s are su peri m posed u pon th e m ean

ru n n i n g l oad i n th e system an d , d epen d i n g u pon th e d yn am i c beh avi or of system , cou l d l ead to fai l u re of th e system com pon en ts.

I n a g ear u n i t th ese fai l u res cou l d occu r as tooth breakag e or pi tti n g of th e g ear

el em en ts, sh aft breakag e or beari n g fai l u re.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

34

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Vibratory motion of gear unit components can take up clearances causing interference problems between gearing elements, or between shafting and bearings or seals.

C.4.2.1 Torsional vibration analysis The vibration analysis shall consider the complete system including prime mover, gear unit, driven equipment, couplings and foundations. Dynamic loads imposed upon a gear unit are the result of the dynamic behavior of the total system and not that of the gear unit alone. The individual components of the system are usually supplied by different manufacturers. Therefore, responsibility for performing the vibration analysis shall rest with the designer of the total system or his designated agent. The vibration analysis should determine all significant system natural frequencies and evaluate the system response to all potential excitation sources. If the analysis indicates a resonant or near resonant condition, the recommended solution is to shift natural frequencies by changing stiffness or mass instead of relying on system damping to limit vibratory amplitudes. Normally, a linear vibration analysis is adequate. However, under certain conditions nonlinear responses can occur and the possibility of their existence should be recognized. It is also advantageous to perform a preliminary vibration analysis early enough in the design procedure to allow for any changes which might be required for detuning purposes.

C.4.2.2 Torsional vibration The vibratory load caused by a steady state torsional vibration of a system is due to the interaction of a periodic excitation, and a natural frequency of the system. The magnitude of the dynamic load caused by this type of vibration is dependent on three factors: magnitude of the excitation, amount of damping in the system, and proximity of the excitation frequency to resonance. Typical sources for steady state excitation include but are not limited to: -

internal combustion engines;

-

reciprocating pumps and compressors;

-

variable frequency drives;

-

pump or compressor impellers.

A torsional vibration in a system can also be caused by a transient excitation which is often called a shock or impact load. Transient conditions occur due to sudden changes in load or speed, or the accelerating or decelerating through system natural frequencies, including the oscillating component of synchronous motors during startup. Transient excitation will produce oscillations at all the natural frequencies of the system. These oscillations will decay and may eventually disappear due to damping. The peak dynamic loads occur during or directly after the disturbance; their magnitudes are not substantially reduced by the damping in the system. Due to the backlash between the geared elements of a gear unit, tooth separation will occur when the vibratory torques in the shafts exceed the average torque, resulting in tooth separation and subsequent impacts. Gear tooth loads due to these impacts can be several times the vibratory torque in the gear shafts. A vibratory torque which is synchronized to the rotation of a gear element can form a cyclic wear pattern on the gear. This wear, which varies around the circumference on the gear element, results in tooth spacing errors of the gear causing noise or even can become a self-generating excitation which reinforces the original excitation.

C.4.2.3 Lateral vibration Dynamic loads at a gear mesh can be caused by a lateral vibration of a gear element in response to an excitation source. The lateral vibration of a rotor system should consider all flexibilities and restraints which will influence the vibratory response of the rotor. In the case of a rotor system comprised of a gear element and shaft, this should include the influence of bearings, foundations, couplings, connecting adjacent rotors and the mating gear element. Lateral vibrations may also be caused by torsional vibrations, but this may not be predicted with a linear analysis.

Copyright American Gear Manufacturers Association ©AGMA 201 4

– All rights reserved

35

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

The most common sources of lateral excitation in a rotor system are unbalance and misalignment. Therefore, care should be given to minimize these factors in the design, manufacture and installation of a rotating system. The lateral response of the system should be evaluated based on the design tolerances for system unbalance and misalignment. Consideration should be given to operation in the proximity of lateral natural frequencies because large vibratory loads may result with relatively low excitation. Fluid film bearings are generally used to support rotors in critical service systems. These bearings possess stiffness and damping properties which vary with speed and load. These non-linear properties should be considered when calculating the lateral natural frequencies of the system. Under certain conditions of operation, these bearings can cause instabilities in the rotor motion which will impart dynamic loads on the gear mesh.

C.4.2.4 Axial vibration Dynamic loads on a gear mesh are sometimes caused by what appears to be an axial vibration. This axial motion is most often the response of the gear element to unbalanced thrust forces. Common sources for these forces are malfunctioning or misaligned couplings, electric armatures mounted off their magnetic center, face runout of thrust collars or compressor wheels, and assembly errors.

C.4.2.5 Vibration measurements and design considerations The results of any theoretical vibration analysis are only as accurate as the mathematical model which is developed to perform the calculations. The correctness of the model of the system is dependent on the accuracy to which the inertia, stiffness, damping and excitation can be ascertained. Since there is always the possibility of the actual system responding differently than the theoretical evaluation, consideration should be given to physically measuring the vibratory loads in the system at the time of initial startup. Obtaining test data related to operational loading on a system has the following advantages: -

establishes confidence that the rotating system will perform satisfactorily or indicate areas where corrective actions are required prior to a system failure;

-

provide a basis for evaluation of systems that may be designed or manufactured in the future; pinpoint system excitations or non-linear responses which were not considered in any theoretical evaluation.

In the design stages it is advantageous to provide design features in the system which would facilitate testing, such as ground surfaces and proper access points for pickups or strain gages. Also in the system design, if it is feasible, consideration should be given to field modifications that could be made with a minimum of operational downtime if damaging vibratory loads were encountered. An example of this would be providing both access to couplings and additional space for coupling changes for detuning purposes.

Alignment C.5.1 Drive train alignment C.5

A gear unit by the nature of its operation is always connected to at least two other pieces of equipment. The successful operation of the gear unit is largely dependent on the alignment of these components. The alignment shall consider the parallel offset, angular misalignment, and axial misalignment. Misalignment during operation not only causes vibration, but superimposes bending stress on the shear stress due to transmitted torque. These stresses cannot be readily calculated but they warrant discussion so the designer can take precautions to minimize their effect. Perfect alignment is almost impossible to obtain; therefore, flexible couplings are used to minimize the effects of the inherent misalignment. However, “flexible” couplings, whether of the gear tooth, spring elements, flexing disc, or elastomeric type, produce forces and moments on their supporting shafts when operating misaligned. The analytical determination of the magnitude of these forces and moments is not fully understood. It can be generalized that: -

the sense and direction are such that they try to bring the supporting shafts in line;

-

significant bending moments may be imposed on supporting shafts;

-

the magnitude of the forces and moments increases with larger angularity across the coupling;

Copyright American Gear Manufacturers Association ©AGMA 201 4

– All rights reserved

36

AMERICAN NATIONAL STANDARD -

ANSI/AGMA 601 1 -J1 4

n otwi th stan d i n g catal og cl ai m s for an g u l ar capaci ty, fl exi bl e cou pl i n g s sh ou l d n ot be l ooked u pon as u n i versal j oi n ts; th ey sh ou l d be g i ven th e best possi bl e al i g n m en t.

Th e system d esi g n er, i n ord er to obtai n m ech an i cal rel i abi l i ty of a cou pl ed sh afti n g system , m u st m ake a com preh en si ve assessm en t of th e operati n g al i g n men t.

Th i s i s a system stu d y an d sh al l i n cl u d e al l

el em en ts of th e system i n cl u d i n g bed pl ates an d /or fou n d ati on s.

An accu rate eval u ati on of th erm al g rowth

for al l com pon en ts from a val i d an d com m on referen ce l i n e i s req u i red .

J ou rn al d i spl acem en t wi th i n

beari n g s, th ou g h g en eral l y sm al l er i n m ag n i tu d e, sh ou l d be con si d ered , parti cu l arl y as i t affects col d or stati c al i g n men t ch ecks. col d

to d yn am i c an d

After d eterm i n i n g th e probabl e m ag n i tu d e of al i g n m en t ch an g e from stati c an d

h ot (i n cl u d i n g

an y peri od i c cycl i c ch an g es th at m ay occu r),

sel ect a cou pl i n g

arran g em en t th at provi d es en ou g h l en g th or span between fl exi bl e el em en ts to keep an g u l ari ty l ow, i n th e reg i on of 5 m i n u tes or l ower. A h ot al i g n men t ch eck i s recomm en d ed at th e ti m e th e u n i t i s pu t i n servi ce.

Th i s sh ou l d be performed

wh en al l tem peratu res h ave stabi l i zed , an d th e system i s tran sm i tti n g rated power at rated speed .

C.5.2 Foundations An oth er ki n d of al i g n m en t probl em com m on l y en cou n tered i n g eared system s i s th e m i sal i g n m en t of pi n i on an d g ear axes d u e to fou n d ati on or bed pl ate twi sti n g or d efl ecti on s. g ear

u n i ts

req u i re

fou n d ati on s

wi th

su ffi ci en t

ri g i d i ty

to

m ai n tai n

I t sh ou l d be recog n i zed th at

al i g n men t

u n d er

operati n g

l oad s.

Rei n forced con crete fou n d ati on s wi th g rou ted -i n sol epl ate are g en eral l y preferabl e to fabri cated steel bed pl ates i n term s of fou n d ati on sti ffn ess, m ass an d d am pi n g ch aracteri sti cs.

A con crete fou n d ati on of

ad eq u ate secti on , on g ood soi l or on su ffi ci en t pi l i n g , i s th e best i n su ran ce to avoi d u n eq u al settl i n g or twi sti n g from oth er cau ses. Fabri cated steel bed pl ates m ake con ven i en t sh i ppi n g an d h an d l i n g frames, bu t are g en eral l y d esi g n ed for stren g th , n ot ri g i d i ty. su m p th erm al

Th ey are freq u en tl y d esi g n ed wi th ou t con si d erati on for th e vari ou s pi pi n g an d /or oi l

expan si on .

Ou td oor i n stal l ati on s on

steel

bed pl ates are parti cu l arl y su bj ect to cycl i c

bowi n g cau sed by th e d ai l y “ri se an d fal l ” of th e su n . Wh en steel bed pl ates are u sed , th e d esi g n er sh ou l d en d eavor to ach i eve two th i n g s: -

arran g e oi l su m ps, pi pi n g , an d weath er protecti on to m i n i m i ze u n sym m etri cal th erm al expan si on ;

-

th orou g h l y i n vesti g ate el asti c d eform ati on of th e bed pl ate d u e to pi pi n g forces an d mom en ts; th en d esi g n th e bed pl ate to el i mi n ate twi sti n g at th e g ear su pports.

C.5.3 System piping Th e forces an d m om en ts i m posed on pu m ps, com pressors an d tu rbi n es by th ei r i n l et an d d i sch arg e pi pi n g are maj or factors i n d efl ecti n g th i s eq u i pm en t an d cau si n g operati n g m i sal i g n m en t. sh ou l d be m ad e to m i n i m i ze pi pi n g effects.

Al l efforts

Lu bri can t su ppl y an d d rai n pi pi n g for th e g ear u n i t sh ou l d be

g i ven si m i l ar con si d erati on .

C.5.4 Installation instructions Th e

system

d esi g n er

sh ou l d

assem bl e

an d

i n teg rate

com pl ete

an d

com preh en si ve

i n stal l ati on

i n stru cti on s coveri n g , as a m i n i m u m , su ch th i n g s as: -

sol epl ate, bed pl ate, m ach i n ery posi ti on an d l evel i n g d etai l s;

-

fou n d ati on bol ti n g an d g rou ti n g d etai l s;

-

col d al i g n m en t d ata -- i n cl u d i n g m eth od of m easu ri n g , rel ati ve posi ti on , an d seq u en ce of al i g n m en t;

-

keyi n g , pi n n i n g an d torq u i n g d etai l s as req u i red ;

-

pi pe su pport an d fl an g e m akeu p d etai l s;

-

al l oth er rel evan t d etai l s th at wou l d oth erwi se be l eft to th e j u d g m en t of th e j ob si te m ech an i c.

C. 6

Additional lubrication considerations

Th e con ti n u ed su ccessfu l operati on an d l on g l i fe of a g ear u n i t i s d epen d en t on th e con stan t su ppl y of a l u bri cati n g oi l of proper q u an ti ty, q u al i ty, an d con d i ti on .

Th e l u bri cati on system h as fi ve fu n cti on s to

perform : -

red u ce fri cti on ;

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

37

AMERICAN NATIONAL STANDARD -

tran sfer h eat;

-

m i n i m i ze wear;

-

tran sfer wear parti cl es;

-

red u ce ru sti n g an d corrosi on .

ANSI/AGMA 601 1 -J1 4

Fai l u re of th e l u bri cati on system to ad eq u atel y perform an y on e or m ore of th ese fu n cti on s m ay resu l t i n prematu re fai l u re of th e g ear d ri ve.

C.6.1 Type of lubricant Two basi c types of oi l s are u sed to l u bri cate g ear d ri ves: -

petrol eu m base;

-

syn th eti c.

Th ere can be a wi d e vari ati on i n th e l u bri cati n g q u al i ti es of oi l s wi th i n each of th ese g en eral types.

Oi l s

are com pou n d ed to m eet speci fi c req u i rem en ts for vari ou s appl i cati on s su ch as g ear oi l s, beari n g oi l s, i n tern al com bu sti on oi l s, worm g ear oi l s, etc.

Th erefore, i t i s i m portan t th at an oi l be sel ected m eeti n g th e

recom m en d ati on s su ppl i ed wi th th e g ear u n i t. Syn th eti c oi l s sh ou l d n ever be su bsti tu ted for petrol eu m base oi l s wi th ou t th e g ear ven d or's approval , si n ce th ese oi l s n ot on l y h ave d i fferen t l u bri cati n g q u al i ti es, bu t al so m ay n ot be com pati bl e wi th m ateri al s u sed i n th e g ear u n i t.

C.6.2 Lubricant selection Th e correct type an d vi scosi ty of oi l sh al l be su ppl i ed i n accord an ce wi th th e ven d or's recom m en d ati on s. Th e fri cti on , wear, fi l m stren g th an d corrosi on protecti on ch aracteri sti cs of d i fferen t types of oi l s can vary wi d el y.

Devi ati on from th e recom m en d ed oi l for th e g ear d ri ve can resu l t i n prematu re wear, fai l u re, or

both .

C.6.2.1 Lubricant quality Lu bri cati n g oi l s for h i g h speed g ear u n i ts sh ou l d be h i g h q u al i ty, refi n ed , paraffi n base petrol eu m oi l s. Th ey sh al l n ot be corrosi ve an d sh al l be free from g ri t or abrasi ves.

As th ey are often ti mes su bj ect to

l arg e fl ow rates an d h i g h operati n g tem peratu res, th ey sh al l h ave g ood an ti foam i n g properti es. Oi l s of a strai g h t m i n eral type sh ou l d be u sed .

H i g h q u al i ty ru st an d oxi d ati on resi stan ce i s d esi rabl e.

Oi l s wi th ad d i ti ves wh i ch en h an ce th ese ch aracteri sti cs sh ou l d be carefu l l y sel ected an d , i f sel ected , freq u en tl y ch an g ed to avoi d accu mu l ati ve separati on of th e ad d i ti ves d u ri n g operati on .

Wh en exposed to

h i g h operati n g tem peratu res i n excess of 90° C, rapi d d eg rad ati on wi l l occu r.

C.6.2.2 Viscosity and viscosity index Oi l s refi n ed i n to l u bri can ts are g en eral l y d eri ved from two types of cru d e oi l , eith er paraffi n base or n apth a base.

Paraffi n

based

oi l s

are

preferred

becau se

th ey

h ave

better

n atu ral

extrem e

ch aracteri sti cs an d better resi stan ce to “th i n n i n g d own ” at h i g h er operati n g temperatu res.

pressu re

N apth a based

oi l s, on th e oth er h an d , req u i re speci al ad d i ti ves i n ord er to possess th i s ben efi t. Th e oi l 's resi stan ce to “th i n n i n g ” i s m easu red by th e vi scosi ty i n d ex. th e resi stan ce to “th i n n i n g ”.

Th e h i g h er th e i n d ex val u e th e better

Oi l s wi th ou t ad d i ti ves of th e paraffi n base type u su al l y h ave vi scosi ty i n d ex

(VI ) val u es of n i n ety (90) or above, wh ereas n apth a base oi l s wi l l exh i bi t l ower val u es, often between twen ty (20) an d th i rty (30).

C.6.3 Oil film G ear el em en ts an d th e su pporti n g beari n g system req u i re a con ti n u ou s su ppl y of properl y sel ected an d con d i ti on ed oi l for su rvi val .

An oi l fi l m of ad eq u ate th i ckn ess n eed s to be establ i sh ed between th e rol l i n g

an d sl i d i n g com pon en t su rfaces to avoi d d am ag i n g wear an d scu ffi n g an d to provi d e com pon en t cool i n g . H yd rod yn am i c

an d

el astoh yd rod yn ami c

th i ckn ess i n beari n g s an d g ear teeth .

l u bri cati on

th eori es

are

com m on l y

u sed

in

an al yzi n g

fi l m

Th e oi l vi scosi ty h as th e g reatest effect on th e fi l m th i ckn ess.

Con seq u en tl y, fai l u re to u se an oi l th at h as both th e proper vi scosi ty an d vi scosi ty i n d ex can resu l t i n fai l u re to prod u ce an ad eq u ate fi l m th i ckn ess for th e g ear teeth an d beari n g s.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

38

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Improper oil film thickness may cause several operational problems. Lack of oil film or inadequate oil film thickness may cause metallurgical tempering of hardened surfaces due to frictional heat, destructive wear, scuffing or pitting of the gear teeth, and frictional melting, plastic flow or failure of the babbitted bearing surfaces. Increased oil viscosity increases frictional power losses and therefore increases the temperature rise and may produce heat energy beyond the capacity of the cooling system. The lubrication system design should successfully achieve a balance of the viscosity and the oil film thickness considerations.

C.6.4 Lubricant supply The oil supply shall meet the requirements set forth in the gear vendor's recommendations. C.6.4.1 Quantity The proper flow rate of oil shall be supplied to the gear drive to ensure adequate oil film formation on the rotor elements, and in cases where babbitted bearings are employed, in the bearing journals, to prevent metal to metal contact of the respective elements. In addition, sufficient flow shall be maintained to assure adequate cooling. Too small a quantity may cause inadequate distribution resulting in potential overheating, whereas too large a quantity may result in excessive churning of the oil which may also result in overheating. C.6.4.2 Pressurized lubrication systems When lubrication systems are self contained, the system should be designed with a flow capacity that is a minimum of 1 0% greater than that initially required to allow for pump wear, slight bearing wear with normal service, or change in oil viscosity due to temperature variations and change of viscosity with use. Where pressurized oil is furnished from a central supply, operating, alarm and shutdown pressures shall be in accordance with the gear unit vendor's specifications. Pressures lower than that recommended may result in reduced flow and overheating. Pressures too high may cause excessive churning and possible gearbox flooding, increasing power loss and also resulting in overheating. Oil pressure to the gear drive should be measured either in the oil passages of the gear unit or at a point as near to the entry of the unit as possible, thus avoiding the inclusion of pressure losses in the piping between the point of measurement and the actual gear supply. C.6.4.3 Lubricant temperature The gear supplier will normally specify the minimum allowable oil temperature for startup. If temperatures lower than this are expected, provisions shall be made to heat and, if possible, circulate the oil prior to startup. The gear drive should not be operated for extended periods at this minimum startup temperature. Oil inlet temperature shall be in accordance with the vendor's specifications. A low supply temperature may result in a change in viscosity causing higher than expected temperature rise in the gear unit and improper oil distribution to the spray jets and bearings. When the oil supply temperature is higher than specified, the oil will be subject to rapid oxidation reducing the life of the oil, and reducing the operating viscosity resulting in an inadequate oil film. This condition can result in overheating, excessive wear and even failure. C.6.4.4 Pressurized system components The system components need to be selected and installed to avoid problems. The following are some suggestions to avoid problems: - Aeration. Care needs to be taken to avoid excessive aeration of the oil. Aeration may result in pump cavitation and decrease the volume of oil to come in contact with the elements of the gear drive; - Oil reservoir. The reservoir should be large enough to allow time for the air to separate from the oil. Return lines to the oil reservoir should return below the oil level. This also includes relief valve bypass lines and any other return lines. These lines should be located as far away from the pump suction line as possible. Baffles properly located in the reservoir will ensure the aerated return oil does not find its way to the suction line until air has had time to escape from the oil; ©AGMA 201 4 – All rights reserved

Copyright American Gear Manufacturers Association

39

AMERICAN NATIONAL STANDARD -

Drai n

l i n es.

Th e

l ocati on

ANSI/AGMA 601 1 -J1 4 of

th e

recom m en d ati on s sh ou l d be fol l owed . of oi l .

Ven ts.

from

th e

g ear

d ri ve

is

cri ti cal ,

an d

th e

ven d or's

Drai n l i n es sh ou l d be si zed so th ey ru n n o more th an h al f fu l l

Th e l i n e sh ou l d sl ope d own at a m i n i m u m of (20 m m /m , 2%) an d h ave a m i n i m u m n u m ber of

ben d s an d el bows. -

d rai n

;

Ven ts sh ou l d be carefu l l y l ocated an d of ampl e si ze to avoi d pressu re bu i l d u p an d al l ow read y

escape of ai r from th e system wi th ou t th e l oss of oi l . con tam i n an ts from th e en vi ron m en t i n to th e oi l .

Ven ts sh ou l d be h i g h en ou g h to avoi d en try of

Often ti m es i t i s d esi rabl e to pl ace th e ven t i n th e

d rai n l i n e n ear th e exi t from th e g ear d ri ve to en su re proper d rai n ag e. retu rn i n g to th e g ear d ri ve as wel l . atm osph ere ou tsi d e i s avoi d ed .

Th e oi l i s fi l tered pri or to

I n th i s m ann er d i rect con tami n ati on of th e g ear d ri ve from th e

Powered oi l m i st el i m i n ators m ay be u sed on ven ts to m i n i m i ze

ven ti n g of oi l m i st from th e system ; th ese u su al l y keep th e i n teri or of th e g ear u n i t an d reservoi r sl i g h tl y bel ow atm osph eri c pressu re an d so al so m i n i mi ze oi l l eakag e probl ems; -

Fi l teri n g .

Proper fi l trati on of th e l u bri can t i s very i m portan t.

-

Su cti on l i n es.

See C. 6. 4. 5 an d C. 6. 5

Th ese l i n es sh ou l d be g en erou sl y si zed to m i n i m i ze pressu re l oss.

Su cti on pressu re

(n et posi ti ve su cti on h ead ) sh ou l d n ot be l ess th an th at recom m en d ed by th e pu m p ven d or.

Th e total

su cti on l oss sh ou l d i n cl u d e th e l oss i n th e pi pi n g , val ves an d fi tti n g s, i n ad d i ti on to th e d i stan ce of th e l i ft.

I f a ch eck val ve i s u sed i n th e su cti on l i n e of posi ti ve d i spl acem en t pu m ps, a pressu re l i m i ti n g

d evi ce sh ou l d be i n stal l ed to protect ag ai n st th e effects of reverse rotati on of th e pu m p; -

Fl u sh i n g .

Before oi l i s ci rcu l ated th rou g h th e g ear d ri ve, a bri d g e secti on con tai n i n g a rem ovabl e

screen i s fi tted between th e su ppl y poi n t an d th e d rai n . n o si g n i fi can t accu mu l ati on of d i rt on th e screen . rapped to d i sl od g e forei g n parti cl es.

Th e system n eed s to be fl u sh ed u n ti l th ere i s

Du ri n g fl u sh i n g th e pi pi n g sh ou l d be h am m er

After fl u sh i n g i s com pl eted , th e su ppl y an d d rai n l i n es are

con n ected to th e g ear d ri ve.

C.6.4.5 Lubricant condition H avi n g

provi d ed

th e proper type an d

th e proper con d i ti on .

g rad e of oi l , Du st,

d i rt,

i t i s al so i m portan t th at th e oi l

g ri t an d

oth er parti cl es i n

th e oi l

be su ppl i ed

m ai n tai n ed

in

el i m i n ated .

Th ese may act as an abrasi ve i n th e beari n g s an d g ear teeth , cau si n g abrasi ve wear.

pressu ri zed oi l sh al l be su ppl i ed th rou g h a fi l ter as speci fi ed by th e g ear u n i t ven d or.

an d

su ppl y sh ou l d

be Th e

Th ese fi l ter systems

sh ou l d be servi ced reg u l arl y to avoi d ci rcu l ati on of con tam i n an ts wi th th e oi l an d to avoi d excessi ve pressu re d rops th rou g h th e fi l ters wh i ch m ay red u ce th e q u an ti ty of oi l su ppl i ed to th e g ear d ri ve. Th e oi l sh ou l d be m ai n tai n ed i n i ts correct ch em i cal con d i ti on to properl y perform . an d m oi stu re can ch an g e th e ch em i cal properti es of th e oi l . u se an d req u i re repl acem en t.

Forei g n m atter, d i rt

Ad d i ti ves u sed i n m an y oi l s are d epl eted wi th

Si n ce m an y factors i n fl u en ce th e u sefu l l i fe of th e oi l , i ts con d i ti on sh ou l d

be an al yzed on a reg u l ar basi s to en su re i ts properti es are wi th i n speci fi cati on .

C.6.5 Varnishing Varn i sh i n g sh ou l d be avoi d ed . face

wi d th s.

Th e

ch an ce

I t i s most preval en t i n g ear u n i ts th at h ave h i g h axi al vel oci ty an d l on g

of excessi ve

fl ash

oi l

tem peratu res

i n creasi n g axi al vel oci ty an d wi th i n creasi n g face wi d th . vel oci ty an d l ower h el i x an g l es. 1.

l ead i n g

to

varn i sh i n g

i n creases

wi th

Axi al vel oci ty i n creases wi th i n creasi n g pi tch l i n e

M an y h i g h speed g ears h ave an axi al m esh i n g vel oci ty exceed i n g M ach

Th e oi l an d ai r m i xtu re bei n g ej ected from th e mesh at th i s h i g h vel oci ty can becom e very h ot d u e to a

com bi n ati on of tu rbu l en ce an d fri cti on wi th th e tooth fl an ks. Varn i sh i n g occu rs wh en som e of th e oi l g ets too h ot an d oxi d i zes, bu t th e l ocati on of th e varn i sh d eposi t m ay n ot correspon d to th e l ocati on wh ere th e h i g h est tem peratu res occu r.

G en eral l y, i n creasi n g th e oi l

fl ow wi l l n ot sol ve th e probl em , si n ce th e spray can n ot d i rectl y reach th e spot wh ere th e h i g h tem peratu re occu rs as th e oi l i s bei n g sq u eezed between th e m esh i n g teeth .

I n creasi n g oi l fl ow m ay resu l t i n extra oi l

en teri n g th e m esh , wh i ch m ay i n crease th e ch u rn i n g l osses of th e oi l /ai r m i xtu re travel i n g th rou g h th e m esh , an d m ay m ake th e probl em worse. Varn i sh i n g ad versel y affects th e cool i n g of th e g ear teeth . Th i s i s mai n l y d u e to th e i n su l ati n g effect of th e varn i sh red u ci n g th e effecti ven ess of th e cool i n g l u be oi l spray. A secon d ary, an d often m i n or, effect i s th at i m m ed i atel y after th e oi l on th e con tact area h as been h eated by g oi n g th rou g h th e m esh , th e i n su l ati n g l ayer of varn i sh i n terferes wi th th e fl ow of h eat from th e very h ot oi l to th e rel ati vel y cool er g ear teeth , th u s al l owi n g th e oi l on th e tooth fl an ks to rem ai n h ot l on g er. Varn i sh i n g al so i n creases th e fri cti on between th e g ear teeth an d th e com pressed l u be oi l an d ai r as i t travel s l on g i tu d i n al l y across th e fl an k,

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

40

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

th ereby ad d i n g ad d i ti on al h eat to th e tooth fl an ks. Th e com bi n ed effects resu l t i n th e g ear teeth g etti n g h otter; th ereby en cou rag i n g an i n creasi n g rate of varn i sh bu i l d u p. Wh en th ere i s varn i sh i n g , i t h as been reported th at separate m etal l u rg i cal ph en om en a m ay al so occu r. I n som e cases wh ere th e eq u i l i bri u m temperatu re i s rel ati vel y h ot d u e to th e en vi ron men t an d g ear m esh d yn am i c acti on , th e con tact area of th e g ear tooth fl an k m ay m etal l u rg i cal l y tran sform to resu l t i n a h i g h er h ard n ess wi th som e d i m en si on al ch an g es wh i ch may al ter th e h el i x m od i fi cati on an d th ereby ad versel y affect g ear l i fe. Wi th h i g h speed g ears, th e bu l k of th e cool i n g sh ou l d be d on e at th e ou tm esh , i m m ed i atel y fol l owi n g th e g en erati on of h eat.

Sprayi n g i n to th e ou tm esh m ay be m ore effecti ve th an at an y oth er l ocati on , as th e

vacu u m created between th e separati n g teeth i s repl aced wi th th e ai r an d oi l m i xtu re sprayed i n to th e ou tm esh .

Th ere m ay be su ffi ci en t oi l for l u bri cati on from a combi n ati on of th e resi d u al oi l from th e spray

at th e ou tm esh an d from th e oi l m i st wi th i n th e g earbox.

Th erefore, si n ce m ost of th e oi l fl ow i s for

cool i n g , very l i ttl e or n o oi l sh ou l d be sprayed i n to th e i n m esh of th e g ears. en ou g h oi l en teri n g th e m esh area to l u bri cate th e tooth fl an ks.

I d eal l y, th ere sh ou l d be j u st

H owever, en d u sers are cau ti on ed n ot to

ch an g e th e oi l sprayi n g arran g emen t provi d ed by th e ven d or. Wh en varn i sh i n g occu rs, on e poten ti al sol u ti on i s to i n stal l an el ectrostati c fi l ter i n an i n d epen d en t ci rcu i t i n ten d ed on l y for fi l trati on . Ch arg ed -parti cl e separators, al so kn own as el ectrostati c fi l ters or preci pi tators, separate carbon an d oxi d i zed parti cl es by fi el d i n d u ced el ectrom ech an i cal forces (ch arg es) on pol ar carbon an d i n sol u bl e oxi d e parti cu l ates. Th e ch arg ed su spen si on s preci pi tate to th e col l ecti on m ed i a or pl ates of th e opposi te ch arg e, to wh i ch th ey ad h ere ti g h tl y. I n som e cases, su ch en h an ced fi l trati on systems

h ave

red u ced

or even

el i m i n ated

varn i sh

d eposi ts.

Th ese

system s

work best wi th

oi l s

of

rel ati vel y l ow vi scosi ty, wh ere a con si d erabl e am ou n t of th e su bm i cron resi n ou s m ateri al can be stri pped ou t of th e oi l .

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

41

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Annex D Illustrative example [Th e foreword ,

footn otes an d

an n exes,

i f an y,

con stru ed as a part of AN SI /AG M A 601 1 -J 1 4,

are provi d ed

for i n form ati on al

pu rposes on l y an d

Specification for High Speed Helical Gear Units. ]

sh ou l d

n ot be

Purpose

D. 1

Th i s an n ex provi d es exam pl es based on th e assu mpti on th at th e g ear set power rati n g i s th e m i n i m u m com pon en t rati n g .

I n practi ce al l compon en t rati n g s n eed to be cal cu l ated to d eterm i n e th e l owest rated

com pon en t.

Example #1 D.2.1 Operational parameters D. 2

Th e g earset to be rated tran sm i ts power from an i n d u cti on m otor rated at 2500 ki l owatts wi th 1 . 0 servi ce factor an d 1 480 RPM to a cen tri fu g al com pressor operati n g at 5000 RPM .

An n ex A i n d i cates th at a

servi ce factor of 1 . 4 i s appropri ate for th i s servi ce.

D.2.2 Gearset parameters Th e th rou g h h ard en ed d ou bl e h el i cal g earset to be rated h as th e fol l owi n g param eters: N u m ber of teeth , pi n i on

53

N u m ber of teeth , g ear

1 79

G ear speed

1 480 rpm

M od u l e, n ormal

3 mm

Pressu re an g l e, n orm al

20°

H el i x an g l e

29° 32’ 30”

Cen ter d i stan ce

400 m m

Ou tsi d e d i am eter, pi n i on

1 88. 75 m m

Ou tsi d e d i ameter, g ear N orm al

ci rcu l ar

623. 24 m m

tooth

th i ckn ess

at

referen ce

d i am eters,

pi n i on

4. 63 m m

(1 82. 76 m m ) an d g ear (61 7. 24 m m ) Face wi d th

255 m m

Overal l face (g ap i n cl u d ed )

300 m m

H ard n ess pi n i on

350 H BW

H ard n ess g ear

300 H BW

Pi n i on speed

5000 rpm

M ateri al g rad e

2

Fl an k tol eran ce cl ass

4

Cu tter wh ol e d epth

7. 0 m m

Cu tter 1 /2 pi tch ad d en d u m

3. 8 m m

Cu tter ti p rad i u s

1 . 28 m m

D.2.3 Rating parameters Th e

pi tti n g

resi stan ce

power rati n g

an d

ben d i n g

cal cu l ated per AN SI /AG M A 21 01 -D04 eq u ati on s.

stren g th

power

rati n g

at

u n i ty

servi ce

factor

are

Wi th th e factors th at h ave a val u e of on e (1 . 0) d el eted ,

th e eq u ati on s are:

P

azu

P

ayu

 

1 b

I

6 1 07

1 d w1 6 1 0

Z K K

7

v

H

  

d  Z Z w1

HP

N

E

bm Y  Y K K 1 t

v

J

FP

N

  

2 (see AN SI /AG M A 21 01 -D04, Eq . 28)

(see AN SI /AG M A 21 01 -D04, Eq . 29)

h

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

42

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

wh ere

ω

1

= 4998. 5 rpm

I

= 0. 22661 (see AG M A 908-B89)

w1

= 1 82. 76 m m

N

= 0. 67230 (pi n i on )

b Z d Z

= 255 m m

Z Y Y m Y

= 0. 71 973 (g ear) 2 0. 5

E

= 1 90. 20 [N /m m ]

J pi n i on

= 0. 56938 (see AG M A 908-B89)

J g ear

= 0. 58768 (see AG M A 908-B89) = 3. 4483 m m (3/cos 29° 32'30”)

t

= 0. 79531 (pi n i on )

N

= 0. 82721 (g ear)

K K C

= 1 .1 3

v

= 1 . 2648 (see AN SI /AG M A 21 01 -D04)

H

σ

SF

K

SF

= 1 . 4 (see an n ex A)

= 1 078. 7 N /m m

HP

 σ

=

= 958. 37 N /mm = 359. 22 N /m m

FP

= 324. 05 N /m m

FP

P

azu



P



P



P



azu

ayu

ayu

P

a

2 2 2 2

(pi n i on @ 350 H BW) (g ear @ 300 H BW) (see AN SI /AG M A 21 01 -D04, fi g u re 8 G rad e 2) (pi n i on ) (see AN SI /AG M A 21 01 -D04, fi g u re 9 G rad e 2) (g ear @ 300 H BW) (see AN SI /AG M A 21 01 -D04, fi g u re 9, G rad e 2)

 4998.5  255   0.22661   1 82.76 1 078.7   0.67230    

6  1 0 7 1 .1 3  1 .2648 

2

  

1 90.2

 4998.5  255   0.22661   1 82.76  958.37   0.71 973   6  1 0 7 1 .1 3   1 .2648 

 

 pi n i on 

 4648 kW

 g ear 

2

  

1 90.2

 51 38 kW

 4998.5 1 82.76  255  3.4483  0.56938  359.21  0.79531  1 .1 3 1 .2648 

6  1 07

1

 4998.5 1 82.76  255  3.4483  0.58766  324  0.8272  1 .1 3 1 .2648 

6  1 07

i s th e l esser of

1

 4787 kW  pi ni on 

 4636 kW  pi n ion 

51 38 4648 4787 463 6 1 .4

1 .4

1 .4

1 .4

D.2.4 Rating conclusions P

a

i s eq u al to th e l esser of

P

azu

or

P

ayu

d i vi d ed by th e servi ce factor, or

P

a

= 4636 ÷ 1 . 4 = 331 1 kW.

Th i s i s

g reater th an th e g ear rated power of 2500 kW, an d so i s acceptabl e.

Example #2 D.3.1 Operational parameters D. 3

Th e g earset to be rated tran sm i ts power from a g as tu rbi n e rated at 1 5 M W an d 821 5 RPM to an el ectri c g en erator operati n g at 3600 RPM on a base l oad cycl e.

Th e servi ce factor i s 1 . 3.

D.3.2 Gearset parameters Th e carbu ri zed d ou bl e h el i cal g earset to be rated h ave th e fol l owi n g param eters: N u m ber of teeth , pi n i on

39

N u m ber of teeth , g ear

89

G ear speed

3600 rpm

M od u l e, n ormal

6 mm

Pressu re an g l e, n orm al

20°

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

43

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

H el i x an g l e

23° 45’

Cen ter d i stan ce

421 . 6 m m

Ou tsi d e d i am eter, pi n i on

268. 8 m m

Ou tsi d e d i ameter, g ear

595. 1 m m

x ), pi n i on Profi l e sh i ft coeffi ci en t ( x ), g ear

Profi l e sh i ft coeffi ci en t (

1

0. 1

2

0. 0

Face wi d th

260 m m

G ap

80 m m

H ard n ess pi n i on an d g ear

58 H RC

M ateri al g rad e

2

Fl an k tol eran ce cl ass

4

Cu tter ti p rad i u s

2. 4 m m

Cu tter d epth

1 4 mm

Cu tter 1 /2 pi tch ad d en d u m

8 mm

Cu tter protu beran ce

0. 25 m m

D.3.3 Rating parameters Th e

pi tti n g

resi stan ce

power rati n g

an d

ben d i n g

cal cu l ated per AN SI /AG M A 21 01 -D04 eq u ati on s.

stren g th

power

rati n g

at

u n i ty

servi ce

factor are

Wi th th e factors th at h ave a val u e of on e (1 . 0) d el eted ,

th e eq u ati on s are:

P

azu

P

ayu

 1 b



Z K K

6  1 07

 1 d w1



6 1 0

  

I

7

v

H

d  Z Z w1

HP

N

E

  

2 (see AN SI /AG M A 21 01 -D04, Eq . 27)

bm Y  Y 1 K K t

v

J

FP

N

(see AN SI /AG M A 21 01 -D04, Eq . 28)

H

wh ere

ω

b Z d Z

= 821 5. 4 rpm

1

= 260 m m

I

= 0. 1 7295 (see AG M A 908-B89)

w1

= 256. 91 m m

N

= 0. 65385 (pi n i on )

Z Y Y m Y

= 0. 68478 (g ear) 2 0. 5

E

= 1 90. 2 [N /mm ]

J pi n i on

= 0. 4721 5 (see AG M A 908-B89)

J g ear

= 0. 4861 1 (see AG M A 908-B89) = 6. 5551 m m (6/cos 23. 75)

t

= 0. 78264 (pi n i on )

N

= 0. 80379 (g ear)

K K C

= 1 .1 3

v

= 1 . 2369 (see AN SI /AG M A 21 01 -D04)

H

σ

SF

=

K

SF

= 1 . 3 (see an n ex A)

HP

= 1 551 . 3 N /mm

FP

= 448. 1 6 N /m m



P



P



azu

azu

 821 5.4  260 

2 2

(see AN SI /AG M A 21 01 -D04, tabl e 3 G rad e 2) (pi n i on an d g ear) (see AN SI /AG M A 21 01 -D04, tabl e 4 G rad e 2)

0.1 7295

6 1 07

1 .1 3 1 .2369 

 821 5.4  260 

0.1 730

6 1 07

1 .1 3 1 .2369 

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

 256.91    256.91  

1 551 .3   0.65385   1 90.2

  

1 551 .3   0.68478   1 90.2

2

  

 25 977 kW  pi n i on 

2

 28 493 kW

 g ear 

44

AMERICAN NATIONAL STANDARD Payu  Payu 

ANSI/AGMA 601 1 -J1 4

 821 5.4  256.91  260  6.5551  0.4721 5  448.1 6  0.78264  1 .1 3 1 .2369 

6  1 07

1

 821 5.4  256.91  260  6.5551   0.4861 1  448.1 6  0.80379  1 .1 3 1 .2369 

6  1 07

Pa is the lesser of

1

 22 31 6 kW  pinion   23 597 kW  gear 

25 977 28 493 22 31 6 23 597 1 .3

1 .3

1 .3

1 .3

D.3.4 Rating conclusions The allowable transmitted power, 1 5000 kW.

Copyright American Gear Manufacturers Association ©AGMA 201 4

– All rights reserved

Pa = 2231 6/1 .3 = 1 7 1 66 kW, is greater than the gear rated power of

45

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Annex E Efficiency [Th e foreword ,

footn otes an d

an n exes,

i f an y,

con stru ed as a part of AN SI /AG M A 601 1 -J 1 4,

E. 1

are provi d ed

for i n form ati on al

pu rposes on l y an d

Specification for High Speed Helical Gear Units. ]

sh ou l d

n ot be

Gear unit efficiency

M ost con tracts for h i g h speed g ear u n i ts req u i re som e g u aran tee of m i n i m u m operati on al effi ci en cy. Wh en h i g h power i s tran sm i tted , a very sm al l i n crem en t of effi ci en cy can represen t su bstan ti al econ om i c g ai n or l oss over th e l i fe of th e g ear u n i t.

To real i ze opti m u m g ear u n i t effi ci en cy, a d etai l ed stu d y of th e

several sou rces of power l oss i s req u i red . Sou rces of power l oss for h i g h speed h el i cal g ear u n i ts i n cl u d e:

m esh , i n tern al wi n d ag e, rad i al an d th ru st

beari n g fri cti on , rol l i n g el em en t beari n g l oad d epen d en t an d i n d epen d en t l osses, seal l oss, an d sh aft d ri ven accessory power req u i remen ts. Th ermal eq u i l i bri u m i s al so an i m portan t factor to con si d er wh en eval u ati n g u n i t effi ci en cy.

I f th e power

l oss from th e g ear d ri ve exceed s th e capaci ty of th e cool i n g system , i n cl u d i n g rad i an t l osses th rou g h th e g ear u n i t casi n g , th e i n l et oi l tem peratu re wi l l n ot be m ai n tai n ed an d wi l l i n fl u en ce th e perform an ce of th e g ear u n i t.

A rou g h ru l e of th u m b i s a 2% l oss per mesh at rated power for g ears reg ard l ess of si ze i n a

paral l el sh aft si n g l e m esh con fi g u rati on ; actu al effi ci en cy m ay vary wi d el y from th i s. Th e h eat to be d i ssi pated from a g i ven power g earbox d oes n ot d epen d on th e si ze of th e g earbox. Bi g g er g ears wi l l d i ssi pate h eat better th an sm al l er on es. I f a g earbox h as n o oi l ci rcu l ati n g system an d i s d epen d i n g on th e rotors d i ppi n g an d spl ash i n g oi l for l u bri cati on , th e h eat wi l l be d i ssi pated en ti rel y th rou g h th e h ou si n g wal l s. Som eti m es fi n s are d esi g n ed on to th e h ou si n g for i n creasi n g th e su rface area to th e atm osph ere an d th ereby i n creasi n g th e th erm al rati n g . Fu rth er capaci ty to d i ssi pate h eat i s som eti m es accom pl i sh ed wi th th e ad d i ti on of a fan or bl ower.

H owever, m ost h i g h speed u n i ts h ave oi l ci rcu l ati n g system s th at

rej ect h eat th rou g h h eat exch an g ers. Fi g u re E. 1

an d Fi g u re E. 2 sh ow a sam pl e breakd own of h ow th e en erg y i s d i ssi pated i n h i g h speed

g ears.

Beari n g 45%

Tooth i n g 55%

Figure E.1 – Origin of gearbox losses Ch u rn i n g an d wi n d ag e (ai r an d oi l ) 80%

Fri cti on 20%

Figure E.2 – Origin of toothing losses Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

46

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

E.1 .1 Mesh losses M esh l osses resu l t from oi l sh eari n g an d fri cti on al l osses wh i ch are d epen d en t on th e speci fi c sl i d i n g vel oci ty an d fri cti on coeffi ci en t. reg i me.

M ost g ear mesh es u n d er th i s stan d ard wi l l operate i n th e EH D l u bri cati on

AGM A/I SO 1 41 79-1

m ay be referred to for m esh power l oss d i scu ssi on s bu t th e form u l as

presen ted th ere h ave n ot been veri fi ed for u n i ts operati n g i n th e speed ran g e or oi l vi scosi ty typi cal for h i g h speed h el i cal g ear u n i ts.

E.1 .2 Internal windage losses Wi n d ag e l osses i n a h i g h

speed

g ear system can

be th e d om i n ati n g

porti on

of th e total

u n i t l oss.

Pocketi n g power l oss d u e to sq u eezi n g of th e com pressi bl e ai r/ai r-oi l m i xtu re from th e mesh i n g zon e form s th e m ai n compon en t of wi n d ag e power l oss. I n ad d i ti on to pocketi n g l oss, wi n d ag e d rag power l oss d u e to ai r d rag al on g th e peri ph ery an d su rfaces of th e rotati n g g ears can al so be expected to con tri bu te to th e total wi n d ag e power l oss.

Becau se of th e sen si ti vi ty of g ear an d u n i t speci fi c rel ati on sh i ps, th i s

com pon en t of g ear box l osses i s very d i ffi cu l t to accu ratel y esti m ate wi th ou t experi men tal d ata from a speci fi c g ear u n i t.

Som e factors th at affect wi n d ag e l osses are:

-

pi tch l i n e vel oci ty

-

th e am ou n t of oi l en trai n ed i n th e ai r su rrou n d i n g th e g ears

-

oi l en trapm en t i n th e m esh ; pu m pi n g acti on

-

h ou si n g -to-rotor cl earan ces

-

g ear bl an k proporti on s

-

oi l vi scosi ty

-

m eth od of m esh l u bri cati on an d cool i n g

-

h ori zon tal or verti cal sh aft offset

-

i n tern al baffl i n g

See E. 2 for m ore i n form ati on .

E.1 .3 Bearing losses Beari n g l osses can be ch aracteri zed based on th e type of beari n g . are u sed i n h i g h speed h el i cal g ear u n i ts.

Typi cal l y, fl u i d fi l m j ou rn al beari n g s

Rol l i n g el em en t beari n g s m ay be u sed i n certai n cases.

E.1 .3.1 Hydrodynamic bearings H yd rod yn am i c j ou rn al beari n g l osses are g en erated th rou g h oi l sh eari n g .

Beari n g l osses are n orm al l y

provi d ed by th e beari n g ven d or, or establ i sh ed l oss cal cu l ati on m eth od s or prog rams can be u sed .

E.1 .3.2 Rolling element bearings Rol l i n g el emen t beari n g l osses are separated i n to l oad d epen d en t l osses an d l oad i n d epen d en t l osses. Eq u ati on s are establ i sh ed to pred i ct th e torq u e on a beari n g as a fu n cti on of th e appl i ed l oad . i n d epen d en t l osses are ch aracteri zed as wi n d ag e an d ch u rn i n g l osses.

Load

Refer to AG M A/I SO 1 41 79-1 for

cal cu l ati on m eth od s.

E.1 .4 Seal losses Wh ere con tact seal s are u sed , fri cti on al l osses d evel op from th e con tact between th e seal an d th e sh aft. Th ese l osses can be esti m ated by u si n g th e m eth od presen ted i n AG M A/I SO 1 41 79-1 .

E.1 .5 Accessory losses Th e power con su m ed by sh aft d ri ven accessori es can be com pu ted by cl assi c pressu re - d i spl acem en t m eth od s i n th e case of fu el

or l u be oi l

pu m ps.

Accessori es oth er th an

pu m ps req u i re appropri ate

eval u ati on . For pu m ps:

P  p

Qp

60 000 e

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

(E. 1 )

47

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

wh ere

P Q p e

p

E. 2 1.

2.

i s power l oss for pu m p (kW) i s pu m p vol u m em etri c fl ow rate (l /m i n ); i s pu m p operati n g pressu re (kPa); i s pu m p effi ci en cy (85% esti m ated ).

References

H an d sch u h , Robert F. , an d M i ch ael J . H u rrel l . Initial Experiments of High-Speed Drive System Windage Losses. Proc. of I n tern ati on al Con feren ce on G ears, G arch i n g , G erm an y. NASA/TM—2011216925. N ASA, Oct. 201 0. Web. M i zu tan i , H ach i ro, Yu u i ch i I si kawa, an d D. P. Town sen d . "Effects of Lu bri cati on on th e Perform an ce of H i g h Speed Spu r G ears. " Proc. of Con feren ce: 5. I n tern ati on al Power Tran sm i ssi on an d G eari n g

3.

Con feren ce, Ch i cag o, I L.

NASA-TM-101969. N ASA, Lewi s Research Cen ter, 1 989. Web. Proceedings of the Institution of

Dawson , P. H . , 1 984, “Wi n d ag e Loss i n Larg er H i g h -Speed G ears, ”

Mechanical Engineers, Part A: Power an d Process En g i n eeri n g , 1 98(1 ), 51 –59.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

48

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Annex F Metallurgical considerations for critical applications [Th e foreword ,

footn otes an d an n exes,

i f an y,

con stru ed as a part of AN SI /AG M A 601 1 -J 1 4,

are provi d ed

for i n form ati on al

pu rposes on l y an d sh ou l d

Specification for High Speed Helical Gear Units. ]

n ot be

For cri ti cal appl i cati on s, con si d erati on m ay be g i ven to req u i ri n g som e or al l of th e fol l owi n g . Th ese su g g esti on s sh ou l d n ot be bl i n d l y ad opted . Th ey m ay be very u sefu l i n som e si tu ati on s, bu t m ay n ot be appropri ate for oth er appl i cati on s.

A m etal l u rg i st fam i l i ar wi th g ears an d

th ei r speci fi c m ateri al s an d

processi n g sh ou l d be con su l ted before ad d i n g req u i rem en ts su ch as th ese. Th ese con si d erati on s are l i sted i n th e typi cal m an u factu ri n g seq u en ce of operati on s an d n ot i n ord er of th ei r i m portan ce. Th e i m pact

on

cost

an d

d el i very

sh ou l d

be

con si d ered

rel ati ve

to

th e

poten ti al

ben efi ts

of an y

ad d ed

req u i remen ts. See AG M A 923-B05 for d efi n i ti on s of m etal l u rg i cal req u i rem en ts an d term i n ol og y. -

G ears prod u ced from m ateri al s th at are cl ean er an d th at h ave better m i cro stru ctu res wi l l h ave i m proved perform an ce.

o o o

U se AG M A 923-B05 G rad e 3 req u i remen ts U se th e m etal l u rg i cal recom m en d ati on s of AG M A 923-B05 as req u i rem en ts. U se i n g ot cast m ateri al rath er th an con ti n u ou s cast m ateri al d u e to cal ci u m i ssu es an d i ts poten ti al n eg ati ve effect on pi tti n g fati g u e l i fe.

o -

Li m i t n on -metal l i c I n cl u si on l evel s to AG M A 923-B05 Al tern ati ves A or B.

H ot work by forg i n g g reatl y i n creases m ateri al properti es; i f properl y d on e i t wi l l ori en t th e g rai n s appropri atel y for th e g ear teeth .

Th e m ateri al total red u cti on rati o wi l l i n fl u en ce th e m ateri al q u al i ty.

H owever, th e total red u cti on rati o wi l l n ot overcom e th e d etri men tal effects of excessi ve or poorl y sh aped i n cl u si on s.

o

Req u i re, as a m i n i m u m , materi al total red u cti on rati o accord i n g to AG M A 923-B05 g rad e 3. A m i n i m u m red u cti on rati o of 7: 1 i s recomm en d ed , wh ere possi bl e.

o

U se ti g h ter u l trason i c test req u i rem en ts, su ch as u se of a referen ce bl ock wi th a sm al l er Fl at Bottom H ol e (FBH ) d i am eter th an speci fi ed i n AG M A 923-B05.

-

Req u i re h eat treatm en t an d m i crostru ctu re accord i n g to AG M A 923-B05 g rad e 3.

o

N i tri d i n g i n creases su rface h ard n ess i n a very th i n l ayer, an d th erefore i n creases th e pi tti n g resi stan ce.

o

N ote th at th e ben d i n g stren g th wi l l i n crease on l y sl i g h tl y, i f at al l .

Teeth th at are carbu ri zed an d h ard en ed wi l l g eneral l y ou tperform d i m en si on al l y i d en ti cal g ear teeth prod u ced by oth er h eat treatm en t processes, bu t m ay be m ore expen si ve. Wh en g ears are

d esi g n ed

to

th ei r

rati n g

l i m i ts

(pi tti n g

or

ben d i n g ),

carbu ri zed

g ears

m ay

be

l ess

expen si ve th an g ears prod u ced by oth er processes, si n ce th ey can be sm al l er. N ote th at case h ard en i n g an d su rface h ard en i n g are materi al ch em i stry d epen d en t an d th e m ateri al ch em i stry sel ected sh ou l d be su i tabl e for th e h ard en i n g m eth od ch osen .

o

N orm al i ze, q u en ch , an d tem per pri or to tooth cu tti n g an d carbu ri zati on for d i storti on con trol an d i m proved m i crostru ctu re.

o

Con si d er th at retai n ed au sten i te for carbu ri zed an d h ard en ed g eari n g can be a con cern at certai n

l evel s.

Th e

opti m al

l evel

vari es

across

i n d u stri es

an d

appl i cati on s.

Abou t

20%

retai n ed au sten i te i s typi cal l y opti m al , m ore or l ess m ay be d etri m en tal .



Th ere

are

vari ou s

m eth od s

to

red u ce

th e

retai n ed

au sten i te

l evel s.

U se

proper

process con trol d u ri n g h eat treatm en t. Col d treati n g at approxi m atel y -75° C can be u sed to red u ce retai n ed au sten i te l evel s. An y col d treatm en t sh ou l d be fol l owed by a tem per. M u l ti pl e tem pers h ave al so been u sed to red u ce retai n ed au sten i te l evel s. N ote

th at i t i s

d i ffi cu l t to

accu ratel y d eterm i n e

metal l og raph i cal l y th e

am ou n t of

retai n ed au sten i te; for m ore i n form ati on see th e AG M A 923-B05 req u i rem en ts an d footn otes for retai n ed au sten i te. I n some cases a h ard n ess test m ay be u sed as an i n d i cati on of th e am ou n t of retai n ed au sten i te.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

49

AMERICAN NATIONAL STANDARD -

ANSI/AGMA 601 1 -J1 4

G ri n d i n g of th e tooth roots can resu l t i n a wel l -sh aped tooth root form , an d can rem ove u n d esi rabl e n ear su rface m i crostru ctu res. H owever:

o

G ri n d i n g of th e roots m ay resu l t i n l ocal i zed temperi n g th at l owers th e su rface h ard n ess an d ben d i n g stren g th .

o

Excessi ve l ocal i zed

h eat g en erated

d u ri n g

g ri n d i n g

m ay cau se cracks.

Even

very smal l

cracks i n crease th e ri sk of tooth breakag e, wh i ch often i s a catastroph i c fai l u re. -

Ti g h ten th e su rface tem per etch I n specti on req u i rem en ts per AN SI /AG M A 2007 or I SO 1 41 04.

o o o

U se Cl ass FA (n o tem peri n g ) as th e acceptan ce cri teri a. U se th e d i p tan k m eth od wh ere si ze perm i ts as opposed to th e swab or spray m eth od s. Bake wi th i n 4 h ou rs after i n i ti al su rface tem per etch I n specti on an d after an y re-i n specti on .

-

Ti g h ten th e mag n eti c parti cl e i n specti on acceptan ce cri teri a.

-

Proh i bi t th e sh ot peen i n g of g ear tooth fl an ks after fi n al fi n i sh i n g becau se sh ot peen ed fl an ks are m ore l i kel y to prod u ce m i cropi tti n g on mati n g g ear teeth .

-

Con si d er i sotropi c su per fi n i sh i n g , both on th e g ear tooth fl an ks an d i n th e g ear tooth root area. Th i s m ay i m prove g ear l i fe an d m ay al so i m prove effi ci en cy an d l ower operati n g temperatu res. I t can al so rem ove u n d esi rabl e n ear su rface m i crostru ctu res.

-

Pl ati n g wi th copper or si l ver m ay h ave ben efi ts d u ri n g i n i ti al ru n -i n , al th ou g h i m proved su rface fi n i sh m eth od s cu rren tl y avai l abl e m ay ach i eve th e sam e or better resu l ts.

o

H yd rog en

em bri ttl em en t

can

cau se

g ear

fai l u res,

an d

care

sh ou l d

be

taken

to

avoi d

i n trod u ci n g h yd rog en to th e parts. H yd rog en can be i n trod u ced to th e m i crostru ctu re vi a aci d s,

el ectropl ati n g ,

con cern ,

or

oth er

proper en g i n eeri n g

h yd rog en

ri ch

j u d g m en t sh ou l d

processes. be

u sed

I f h yd rog en

to h an d l e

em bri ttl em en t

th ese

si tu ati on s.

is

a

Care

sh ou l d be taken wh en el ectropl ati n g to avoi d probl em s wi th h yd rog en em bri ttl em en t.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

50

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Annex G Assembly designations [The foreword, footnotes and annexes, if any, are provided for informational purposes only and should not be construed as a part of ANSI/AGMA 601 1 -J1 4, Specification for High Speed Helical Gear Units. ]

L-R

L-L

R-R

R-L

L-LR

LR-L

LR-R

R-LR

Plan views

LR-LR

Plan views

NOTES: 1 . Code: L = Left; R = Right 2. Arrows indicate line of sight to determine direction of shaft extensions. 3. Letters preceding the hyphen refer to number and direction of high speed shaft extensions. 4. Letters following the hyphen refer to number and direction of low speed shaft extensions.

Figure G.1 - Parallel shaft spur, helical and herringbone gear drives, single or multiple stage

©AGMA 201 4 – All rights reserved

Copyright American Gear Manufacturers Association

51

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Annex H Purchaser's data sheet [The foreword, footnotes and annexes, if any, are provided for informational purposes only and should not be construed as a part of ANSI/AGMA 601 1 -J1 4, Specification for High Speed Helical Gear Units. ]

H.1

Purpose

Data sheets in SI and U.S. customary units are provided to facilitate communication between purchaser and vendor. The purchaser should fill in the left side of the data sheet.

Copyright American Gear Manufacturers Association ©AGMA 201 4

– All rights reserved

52

AMERICAN NATIONAL STANDARD

Copyright American Gear Manufacturers Association ©AGMA 201 4

– All rights reserved

ANSI/AGMA 601 1 -J1 4

53

AMERICAN NATIONAL STANDARD

Copyright American Gear Manufacturers Association ©AGMA 201 4

– All rights reserved

ANSI/AGMA 601 1 -J1 4

54

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Annex I Guideline for lubricant viscosity grade selection [Th e foreword ,

footn otes an d

an n exes,

i f an y,

con stru ed as a part of AN SI /AG M A 601 1 -J 1 4,

are provi d ed

for i n form ati on al

pu rposes on l y an d

Specification for High Speed Helical Gear Units. ]

sh ou l d

n ot be

Guidelines

I.1

I n th e absen ce of an el astoh yd rod yn am i c (EH D) an al ysi s, th e fol l owi n g tabl e i s offered for th e ven d or to sel ect

an

appropri ate

com pl em en ted

wi th

an

vi scosi ty

g rad e

appropri ate

for

th ei r

l u bri can t

appl i cati on .

ad d i ti ve

Th e

packag e

to

vi scosi ty

provi d e

a

sel ecti on fi n i sh ed

sh ou l d

l u bri can t

be wi th

properti es su ffi ci en t to m eet th e overal l n eed s of th e appl i cati on . Tabl e I . 1

provi d es th e esti m ated I SO vi scosi ty g rad es for a g i ven bu l k oi l tem peratu re an d pi tch l i n e

vel oci ty com bi n ati on .

I n th e case of m u l ti pl e stag e g ear u n i ts, i t i s recomm en d ed to u se th e h i g h est pi tch

l i n e vel oci ty of th e m esh es.

Con si d erati on sh ou l d be g i ven to th e vi scosi ty req u i rem en ts of th e oth er g ear

m esh es i n th ese i n stan ces.

A com pl ete an al ysi s of th e effects of th e vi scosi ty on al l g ear m esh es an d on

th e beari n g s sh ou l d be perform ed . Wh en th ere i s a sh ared l u bri cati on system , con si d erati on sh ou l d be g i ven to oth er com pon en ts i n th e g ear d ri ve su ch as beari n g s an d seal s, an d so oth er vi scosi ty l evel s m ay be req u i red .

Table I.1 – Approximate viscosity grade for oils having minimum viscosity index of 90 1 ) Pitch line velocity, m/s 3) Bulk temperature, 35 50 75 1 00 1 50 200 °C 2) I SO VG 46

I SO VG 46

I SO VG 32

I SO VG 32

I SO VG 32

50

I SO VG 46

I SO VG 46

I SO VG 46

I SO VG 46

I SO VG 32

I SO VG 32

80

I SO VG 68

I SO VG 46

I SO VG 46

I SO VG 46

I SO VG 46

I SO VG 32

95

I SO VG 68

I SO VG 46

I SO VG 46

I SO VG 46

I SO VG 46

I SO VG 32

1 05

5)

NOTES: 1)

I SO VG 68

I SO VG 68

I SO VG 46

CG V

4)

CG V

4)

CG V

4)

40

CG V

4)

Th i s tabl e assu m es th at th e l u bri can t retai n s i ts vi scosi ty ch aracteri sti cs over th e expected oi l ch an g e i n terval .

Con su l t th e l u bri can t su ppl i er i f th i s d oes n ot appl y. 2)

Bu l k tem peratu re i s th e averag e tem peratu re i n th e l u bri can t d rai n l i n e.

For sel f-con tai n ed u n i ts, i t i s th e su m p

oi l tem peratu re. 3)

Determi n e pi tch l i n e vel oci ty of al l g ear m esh es.

Sel ect th e vi scosi ty g rad e for th e cri ti cal g ear m esh taki n g i n to

accou n t col d startu p con d i ti on s. 4) 5) 6)

Con su l t g earbox ven d or (CG V) i f operati on i n th i s ran g e i s expected Syn th eti c oi l s are recomm en d ed . Sh ad i n g d el i n eates vi scosi ty g rad es.

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

55

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Annex J Assembly, functional testing and preservation of gearboxes [The foreword, footnotes and annexes, if any, are provided for informational purposes only and should not be construed as a part of ANSI/AGMA 601 1 -J1 4, Specification for High Speed Helical Gear Units. ]

J.1 Gearbox assembly procedures This procedure covers assembly of gearboxes and gives recommendations for cleaning, storage, handling, and assembly of gearbox components. Most of these recommendations are simply good practice that should always be used, but a few may only be applicable to custom applications where extreme cleanliness is required. Those few will add cost and may not improve performance or life, the benefit depends on the specific system to which they are applied. Therefore, users should evaluate the costs and benefits of each of these procedures before requesting them. Solid particulates create abrasive wear, adhesive wear, and debris dents that shorten the life of gears, bearings and seals. Therefore, gearboxes should be free of solid contaminants for maximum longevity of gearbox components. Assembly should be done in a clean area by skilled technicians using clean assembly procedures to minimize built-in contamination. Following assembly the gearbox should be thoroughly flushed by circulating clean, particulate free, oil through it. This may be done with the lubrication system that will be used for the test.

J.1 .1 Dedicated cleaning station a. Monitoring gearbox cleanliness provides a means to control assembly practices to maintain gearbox cleanliness. b. All components should be cleaned prior to assembly and delivered to the assembly room in a clean condition. c. Housing, gears and shafts should be cleaned in a parts washer system equipped with high pressure spray jets using heated aqueous-based solvents. Cleaning should include wash, rinse, and dry stages. Lubrication system components should have all internal surfaces and passages cleaned. For cast passages or welded sections, cleaning should include use of an appropriately sized wire brush. Following cleaning, all lubrication system components should be flushed with clean filtered oil and all ports should be sealed. d. Rolling element and other bearings that are received from the vendor fully cleaned should be delivered to the assembly room in their original OEM packaging. Otherwise, the bearings should be cleaned in the parts washer. J.1 .2 Storage and handling Any component requiring storage should be cleaned, packaged, wrapped, and stored such that dust, dirt, and particulates are not present on or in these components when they are delivered to the assembly room. The ends of the lubrication system pipes, tubes, and hoses should be plugged or sealed. Loose fittings should be in sealed bags or boxes. All ports in heat exchangers, radiators, manifolds, pumps, and related hardware should be plugged, or the components stored in sealed bags. J.1 .3 Dedicated assembly room Ideally, the gearbox assembly room should be isolated and physically separated from other production areas, especially those areas where the following or similar activities are performed: a. Any hot work activities such as soldering, brazing, welding. b. Removal of metal, composites, plastic, paint, coating or other materials from surfaces by any means whatsoever, including deburring. c. Cutting, shaping, or drilling of any materials. d. Additional precautions to minimize the chance of particulates include: - Doors and windows of the gearbox assembly room should not be opened for ventilation. Heating and cooling should be provided by a system that delivers filtered air to the assembly room at all times. - Floors should be sealed and coated to form a smooth non-porous surface to minimize accumulation of dirt, dust, and other particulates, and facilitate routine housekeeping. Surfaces of walls and ceiling should be fully clad with sheet stock such as drywall. To facilitate routine ©AGMA 201 4 – All rights reserved

Copyright American Gear Manufacturers Association

56

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

h ou sekeepi n g acti vi ti es, th ey sh ou l d al so be seal ed an d pai n ted so th ere i s n o m ateri al th at can l oosen an d en ter th e en vi ron m en t. -

M ateri al h an d l i n g eq u i pmen t su ch as overh ead g an try cran es sh ou l d

be rou ti n el y cl ean ed

of

accu m u l ated d i rt, d u st, an d oth er d ebri s. I n specti on of i n com i n g com pon en ts: Al l g earbox compon en ts sh ou l d be i n spected for cl ean l i n ess as th ey are recei ved i n th e assem bl y room . free cl oth .

Th i s sh ou l d i n cl u d e wi pi n g th e com pon en t wi th a cl ean , wh i te, l i n t-

An y com pon en t th at d i scol ors th e cl oth sh ou l d be rej ected an d retu rn ed to th e cl ean i n g stati on

to be re-cl ean ed .

J.1 .4 Covering work in-process: Al l g earbox com pon en ts sh ou l d m ateri al s su ch

be wrapped or com pl etel y covered wi th cl ean ,

as l i n t-free rag s,

cl oth ,

d u st free covers or

or pl asti c wh en ever g earbox assem bl y i s h al ted

d u ri n g

work

breaks, at th e en d of th e work sh i ft, wh en ever h ou sekeepi n g acti vi ti es are perform ed , an d wh en th e ai r cl ean i n g system i s bei n g servi ced or i s oth erwi se off-l i n e. J.2

Lubrication system flushing and verification of cleanliness

Th e l u bri cati n g oi l system sh ou l d be th orou g h l y cl ean ed an d fl u sh ed before con n ecti n g i t to th e g earbox. Th e fl u sh i n g m ay n ot be wi th i n th e con trol of th e g ear su ppl i er, su ch as wh en th ere i s a sh ared l u bri cati on system

fu rn i sh ed

by oth ers.

N everth el ess,

veri fi cati on

of cl ean l i n ess

for su ch

system s

sh ou l d

be

con si sten t wi th systems th at are fu rn i sh ed by th e g ear su ppl i er. Th e Lu bri cati on system fl u sh i n g an d veri fi cati on of cl ean l i n ess m ay be com bi n ed i n to a si n g l e proced u re i n th e seq u en ce sh own : 1. 2.

Rem ove fi l ters from system I n stal l screen s 1 50 m i cron (1 00 m esh 1 00 × 1 00 per i n ch ) pl ai n -weave stai n l ess steel wi re m esh wi th a wi re d i am eter of 0. 1 0 m m an d open i n g s of 0. 1 5 m m on l u bri cati on system ou tl et(s) an d tem porari l y con n ect

back

com pon en ts, reservoi r.

to

reservoi r.

i n cl u d i n g

Th ese

cool ers,

so

screen s

th at al l

oi l

sh ou l d passes

be

d own stream

th rou g h

a

of

screen

al l

l u bri cati on

before

retu rn i n g

system to

th e

N ote th at n o oi l sh ou l d g o th rou g h an y of th e beari n g s or g ear m esh d u ri n g th e fl u sh i n g

proced u re. 3.

Fi l l reservoi r wi th cl ean oi l

4.

H eat oi l to n orm al reservoi r operati n g tem peratu re

5.

Ci rcu l ate oi l th rou g h th e com pl ete system for a m i n i m u m of on e h ou r.

N ote th at i t m ay take m an y

d ays of fl u sh i n g before acceptabl e cl ean l i n ess l evel s are ach i eved . 6.

Every secti on of pi pi n g sh ou l d be fl u sh ed an d veri fi ed for cl ean l i n ess, th i s m ay req u i re m u l ti pl e setu ps.

7.

Wh en th e j ob oi l pu m p can n ot be u sed for fl u sh i n g (su ch as wh en i t i s d ri ven from th e g earbox), or wh en h i g h er oi l vel oci ti es are d esi red , a separate fl u sh i n g pu m p m ay be u sed .

I t i s ad van tag eou s to

u se a l arg er capaci ty pu m p so th e oi l vel oci ty d u ri n g fl u sh i n g i s h i g h er th an i t wi l l be d u ri n g n orm al operati on . 8.

To free parti cu l ate from oi l con tacti n g su rfaces, pi pes, cool ers, an d val ves sh ou l d be h am m ered freq u en tl y d u ri n g test.

H am m eri n g m ay be accom pl i sh ed by u si n g vari ou s m ean s, su ch as ph ysi cal

h am m eri n g , ai r i n j ecti on , or m ech an i cal vi brati n g eq u i pm en t.

Care sh ou l d be taken to avoi d d am ag e

to eq u i pm en t d u ri n g th i s process. 9.

Rem ove fi l ter screen s an d veri fy cl ean l i n ess.

Wi th “d ” bei n g th e sm al l est pi pe i n tern al d i am eter (mm )

l ead i n g to th e screen , th ere sh ou l d be n o m ore th an 1 + d * d /1 25 parti cl es fou n d on th e screen after a m i n i m u m of 1 h ou r of fl u sh i n g . 1 0. I f cl ean l i n ess l evel i s n ot ach i eved , take appropri ate acti on to i d en ti fy an d rem ove th e con tam i n ati n g featu re, an d th en repeat process of veri fi cati on . 1 1 . U pon compl eti on of an acceptabl e fl u sh , veri fi cati on d ocu men tati on sh ou l d

be com pl eted .

1 2. I n stal l j ob fi l ters i n system . J.3

Tooth contact inspection prior to pre-functional testing

G ear tooth

con tact pattern s i n d i cate h ow wel l

com pati bi l i ty of a pi n i on an d g ear.

a g earset i s al i g n ed

an d

h el p d eterm i n e

operati on al

Stati c n o-l oad con tact pattern s m ay be i n spected i n a rol l stan d or i n

an u n stressed g ear h ou si n g , u si n g Pru ssi an bl u e or appropri ate m arki n g compou n d . A rol l stan d can be u sed to al i g n th e g earset axes to eval u ate d evi ati on s from th e d esi g n profi l e an d h el i x. Con tact pattern s

Copyright American Gear Manufacturers Association ©AG M A 201 4 – Al l ri g h ts reserved

57

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

obtained in a gear housing include gear tooth deviations, gear housing bore deviations, and effects of bearing clearance.

J.3.1 Procedure for the Inspecting and recording of static tooth contact patterns: This procedure covers inspection of no-load gear tooth contact patterns using soft marking compound, with the gearset on a roll stand or in a gear housing. Results of this check are compared to the vendor’s requirements. The basic test procedure is given in AGMA 91 5-1 -A02, Clause 1 0. The following additional procedures should also be used. NOTE: The required materials and recommended application methods are detailed within ISO/TR 1 0064-4 Annex A, which describes the use of contact patterns to control proper rotor alignment.

J.3.1 .1 Recording results The representative reading results from marking compound being transferred from the wheel teeth to the pinion teeth. To record the results after transfer: 1 . Place a length of tape over the entire length of one of the representative loaded and non-loaded flanks of the pinion tooth where the contact transfer has occurred. 2. Allow tape to fold over the edges and top land to define the tooth boundaries. 3. Starting at one end, carefully peel the tape from the tooth. 4. Place one end of the tape with adhesive side down, on white paper and carefully spread the tape across the paper. 5. Annotate the tape to identify the tooth tip, root, and reference end, and whether it is a loaded or unloaded flank. 6. As necessary, repeat tape lift-offs for remaining teeth inspected in identifying letter sequence. 7. Electronically record storage of the results in color, not black and white. J.3.1 .2 Interpretation of results Tape lift-off, unless otherwise specified, should be interpreted in accordance with Clause 1 0.4 of AGMA 91 5-1 -A02. J.3.1 .3 Acceptance criteria Contact pattern- The contact pattern should be within limits specified on the engineering drawing of the vendor. NOTE: Other acceptance criteria may be required, particularly for gears with modified helices such as: referenced non-loaded side contact and static tooth mesh gap values as measured with a feeler gage.

J.3.1 .4 Static tooth contact report The report should include the following: Description of the gearset, description of roll stand or gear housing, tape lift-offs, record of verifications and calibrations. J.3.2 Pre-test lube oil requirements - Lubricant cleanliness: The ISO 4406 cleanliness should be measured with an automatic particle counter in accordance with ISO 1 1 500. - Reservoir lubricant cleanliness: The lubricant in the lubrication system reservoir should be circulated through an offline filter with β 3 > 200 µm until the ISO 4406 cleanliness code is 1 6/1 4/1 1 or better. - Gearbox lubricant cleanliness: After the lubrication system reservoir is sufficiently clean, the reservoir should be connected to the gearbox and the lubricant should be circulated through the gearbox lubrication and filtration system until the ISO 4406 cleanliness code is 1 7/1 5/1 2 or better. J.4 Procedure for the Inspecting and recording of no-load, part loaded and loaded dynamic tooth contact patterns This procedure covers dynamic inspection of gear tooth contact patterns using hard lacquer under load with the gearset in a gear housing. ©AGMA 201 4 – All rights reserved

Copyright American Gear Manufacturers Association

58

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Note that such a check usually shows area of contact at the test load, but does not reveal variations in contact pressure over the flank. Dynamic contact pattern tests should be performed on a gearset installed in gear housing.

J.4.1 Required materials - Contact pattern tests should be performed using a hard lacquer layout fluid, such as DYKEM RED Part No. 80496 or equivalent. - An appropriate thinner for the product should be used as needed. - The layout fluid should be applied with spray or a soft, fine-bristle brush. J.4.2 Procedure - Cleaning- pinion and wheel teeth should be cleaned with clean lint-free cloth soaked in fast drying solvent to remove all oil. - Applying layout fluid to brush- maximum brush load should be adjusted to prevent runs, sags or an overly thick coating. - Calibrating layout fluid thickness- operator training and application should be calibrated to maintain accuracy and repeatability of coating thickness. Proper coating thickness is achieved when gear tooth surface is clearly visible through the coating, and the coating is free of runs, sags, or thick areas. Viscosity of layout fluid should be controlled to ensure uniform and repeatable coating thickness. Viscosity may be reduced by diluting the layout fluid with an appropriate thinner, such as DYKEM Remover and Cleaner. - Applying layout fluid to pinion teeth- the loaded flanks of at least 3 adjacent teeth on both the pinion and wheel elements should be applied in at least 3 location’s spaced 1 20 degrees apart. - Verifying layout fluid adherence- after the layout fluid has dried for at least 5 minutes, the coating should be tested for adherence by wiping teeth with a clean, soft cloth using firm finger pressure. There should be no transfer of layout fluid to the cloth and no chipping of the layout fluid coating. - Verifying layout fluid cleanliness- after the layout fluid has dried for at least 5 minutes, the coating should be tested for cleanliness by wiping coated teeth with light finger pressure. Sense of touch should indicate a smooth, hard surface free of roughness or grit. - Immediately after the layout fluid coatings have been verified, all gear teeth should be sprayed with clean oil to prevent corrosion. - Predicted contact pattern - Gears sets with unmodified helices will ideally have contact across the entire flank at no load, and still have good contact at full load. Gear sets with modified helices will only produce a full load contact pattern when operating at the design load. This may not be possible to demonstrate on a test stand. For tests of gears with modified helices that will be conducted at less than full load or less than full speed, a predicted contact pattern for the test conditions should be established prior to the test. - Non-drive flank contact pattern check - Unidirectional gear sets which have the non-drive flanks ground without a helix modification may use a no load contact pattern check of the non-drive flanks in addition to, or in some cases instead of, the drive flank contact pattern check. The non-drive flank contact pattern check can verify the proper alignment of the gears, and may be used as a reference verifying the relationship with the modified drive side flanks. - Test duration - Run time at no load should be 2 hours minimum, and should be long enough to establish thermal equilibrium. Longer run times are required with high-speed gear sets and thick oil film thickness. When the test also includes multiple loads, the run time at each load should be at least 20 minutes. - Recording results - Record results with color photographs or scans of all contact patterns taken on the teeth of the pinion and wheel. The field of the photograph should show the entire tooth. Large teeth may require close-up photographs of contact patterns in additional to overall photographs. Annotate the photographs to identify pinion or wheel, tip, root, reference end and loaded or unloaded side. - Interpretation of results- The contact pattern should be interpreted for percent contact area. ©AGMA 201 4 – All rights reserved

Copyright American Gear Manufacturers Association

59

AMERICAN NATIONAL STANDARD -

J.5

ANSI/AGMA 601 1 -J1 4

Acceptance criteria- contact patterns should be within the limits specified for pinion and wheel. For unmodified helices the criteria generally is 80% contact. For modified helices the recorded contact should be reasonably close to the predicted contact for the test conditions.

Preservation and transport preparation procedures

When the gear unit or gearset is not going to be in use for an extended period of time, protection against corrosion including internal and external components is essential. Consideration of the storage environment such as indoors versus outdoors, temperature and humidity should be considered in the material selected for preservation.

J.5.1 Post test inspection and cleaning preparations After the final test run, all components should be inspected and properly preserved prior to final assembly. If required, cleaning should include wash, rinse, and dry stages. The internal surfaces and passages of all lubrication system components should be flushed with clean filtered oil and all ports should be sealed. The internal surfaces and passages of all lubrication system components should be flushed with clean filtered oil and all ports should be sealed. Bearings should be cleaned and preserved.

J.5.2 Preservation Preservative should be applied to all unpainted surfaces including gears and bearings, but not to stainless steel surfaces. The preservative should be suitable for both the storage environment and the length of time the gear unit or elements will be in storage. Oil soluble preservatives can be used for storage up to six months when the environment is not severe. With special care oil soluble preservatives may be suitable for up to 1 8 months of storage. Extended care can be supplemented by spraying preservative through access ports for internal protection and directly to the outside surfaces where applicable. When oil soluble preservatives are not sufficient, heavy duty preservatives that will require a solvent for removal prior to commissioning should be used.

J.5.3 Storage and handling All equipment should be packed for transport in accordance with the contractual agreements with the purchaser. Any component requiring storage should be cleaned, packaged, wrapped, and stored such that dust, dirt, and foreign particles are not present on or in these components. The ends of the lubrication system pipes, tubes, and hoses should be plugged. Loose fittings should be stored in sealed bags or boxes. All ports in heat exchangers, radiators, manifolds, pumps, and related hardware should be plugged, or the components stored in sealed bags. Shafts should be secured against axial movement during transportation. Suitable measures, such as clamping devices, need to be used to prevent movement of the input and output shafts, particularly for shafts without thrust bearings. Lifting locations should be clearly identified to assure the gear unit is properly supported during loading, transportation and unloading.

Copyright American Gear Manufacturers Association ©AGMA 201 4

– All rights reserved

60

AMERICAN NATIONAL STANDARD

ANSI/AGMA 601 1 -J1 4

Bibliography [The foreword, footnotes and annexes, if any, are provided for informational purposes only and should not be construed as a part of ANSI/AGMA 601 1 -J1 4, Specification for High Speed Helical Gear Units. ]

1. 2. 3. 4. 5.

Geometry Factors for Determining the Pitting Resistance and Bending Strength of Spur, Helical and Herringbone Gear Teeth AGMA 927-A01 , Load Distribution Factors - Analytical Methods for Cylindrical Gears Ehrich, Fredric F., Handbook of Rotordynamics, McGraw-Hill, Inc., 1 992 ISO 1 0064-4:1 998, Code of inspection practice -- Part 4: Recommendations relative to surface texture and tooth contact pattern checking ISO 1 1 500:2008, Hydraulic fluid power -- Determination of the particulate contamination level of a liquid sample by automatic particle counting using the light-extinction principle AGMA 908-B89,

Copyright American Gear Manufacturers Association ©AGMA 201 4

– All rights reserved

61