AGMA-6001-D97-1997-R-2003.pdf

S T D - A G M A bOüL-D97-ENGL 1997 üb87575 0005424 28T R ANSIIAGMA 6001 -097 (Revision of ANWAGMA 6001 -C88) AMERICAN NATIONAL STANDARD Design und Selection of Components for Enclosed Gear Drives I I AGMA STANDARD STD-AGMA b001-D77-ENGL 1997 Ob87575 0005425 L L b W their existence does not in any respect preciude 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 interpre- tation 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. Fables and other self-supporting sections may be quoted or extracted in their entirety. Credit lines should read: Extracted from AGMA 6001 -D97, Design and selection of Com- ponents for Enclosed G e a r Drives, with permission of the publisher, American Gear Manu- facturers Association, 1500 King Street, Suite 201, Alexandria, Virginia, 22314.1 Approved August 7,1997 ABSTRACT This standard outlines the basic practices for the design and selection of components, other than gearing, for use in commercial and industrial enclosed gear drives. Published by American Gear Manufacturers Association 1500 King Street, Suite 201, Alexandria, Virginia 22314 Copyright O 1997 by American Gear Manufacturers Association All rights resewed. No part of this publication may be reproduced in any form, in an electronic retnevai system or otherwise, withoui prior written permission of the publisher. Printed in the United States of America ISBN: 1-55589-683-9 ii -,-,- AMERICAN NATIONAL STANDARD ANSIIAGMA 6M)l-D97 Contents Page Foreword . iv 1 scope 1 2 Definitions and symbols . 1 3 Designconditions 1 4 Shafts 4 5 Keys 19 6 Bearings . 20 7 Housings 21 8 Threaded fasteners 22 9 Miscellaneous components . 22 Tables 1 2 Symbols used in equations 2 Modifying factor for stress concentration. 4 - typical values for keyways in solid round steel shafts 14 Figures 1 Designcriteria . 5 2 Cyclicloading . 7 3 Stress convention showing orbiting element 7 4 Surface finish factor. k, . 10 5 Sizefactor. . 11 6 ReliabMyfactor. 11 7 Notch sensitiwty - steel. q 12 8 Theoretical stress concentration factor in bending for a circular shaft with a 9 Theoretical stress concentration factor in bending for a circular shaít with 1 O Theoretical stress concentration factor in bending for a circular shaft with a 11 Torsional deformation 15 12 square shoulder. k; (nominal stress is calculated at diameter Q) . 13 a u-notch. k; (nominal stress is calculated at diameter Q) radial hole. k; (based on full section without considering hole) . 14 Bending deflection intermediate concentrated load . 16 13 Bending deflection overhung concentrated load . 17 14 Bending deflection intermediate concentrated moment . 17 Bending deflection overhung concentrated moment 18 17 Average shaft and hub radius . 19 18 Variation of coefficient of friction versus the bearing parameter . 21 13 15 16 Axial deformation . 18 Annexes A Allowable stresses for typical key and keyway materials 25 B Allowable stresses for typical threaded fasteners 27 C Interference fit torque capacity 29 D E Sample problems . transmission shaft design . 33 F G References . 41 Previous method . shaft design . 31 Sample problems . deflection . 37 iii S T D - A G M A bOOL-D77-ENGL 1997 W Ob87575 000542b 052 -,-,- ANWAGMA 6001497 AMERICAN wnowL STANDARD Foreword r h e foreword, footnotes, and annexes, if any, in this document are provided for informational purposes only and are not to be construed as a part of ANSVAGMA Standard 6001-D97, Design and Selection of Components for Enclosed Gear Drives. AGMA 260.02 was approved by the AGMA membership on February 1,1973, and issued in January of 1974. It consolidated with minor revision, information contained in the following superseded AGMA Standards: AGMA 255.02 (November 1964), Bolting (Allowable Tensile Stress) for Gear Drives; AGMA 260.01 (March 1953), Shaföng -Allowable Torsional and Bending Stresses; AGMA 260.02 also incorporated allowable stresses for keys; AGMA 265.01 Bearings -Allowable Loads and Speeds. , The purpose of AGMA 6001 -C88, as a replacement for AGMA 260.02, was to establish a common base for the design and selection of components for the different types of commercial and industrial gear drives. AGMA 6001-C88 was expanded to include a generalized shaft stress equation which included hollow shafting, miscellaneous components, housings, and keyway stress calculations. All design considerations were revised to allow for 200 percent peak load for helical, spiral bevel, spur and herringbone gearing, and 300 percent peak load for wormgearing. The bearing section was Lipdated to include consideration of life adjustment factors, bearing lives other than 5000 hours and reliability levels other than L1 O. During the preparation of AGMA 6001 -C88, a considerable amount of time was spent on the shaít design section in an effort to include the most recent theories on shaft stresses and material characteristics. The standard included the existing practice for shaft design, and for reference purposes, appendix C included a description of, and excerpts from, ANSVASME 81 06.1 M, Design of Emsmission Shafang, published in 1985. AGMA 6001 -C88 was approved by the membership in May 1988 and approved as an American National Standard on June 24, 1988. This revision, AGMA 6001 -D97, has been expanded to include more recent theories on shaft design and analysis. Also, equations for shaít deformation were added. AGMA 6001 4 9 7 was approved by the membership in October 1996 and approved as an American National Standard on August 7, 1997. Suggestions for improvement of this standard will be welcome. They should be sent to the American Gear Manufacturers Association, 1500 King Street, Suite 201, Alexandria, Virginia 22314. iv S T D - A G M A bOOL-D97-ENLL I 9 9 7 Ob87575 0005427 T99 = - -,-,- AMERICAN NATIONAL STANDARD ANSI/AGMA 6001-097 PERSONNEL of the AGMA Component Design Committee Chairman: D. McCarthy . Dorris Company Vice Chairman: D. Cressman Philadelphia Mixers Corporation ACTNE MEMBERS R. Errichello . GEARTECH J.B. Hagaman Cone Drive Operations, Inc. R. Holzrnan Milwaukee Gear Company, Inc. J. Lisiecki The Falk Corporation D.R. McVie . Gear Engineers, Inc. K. Newton . Rockwell AutomationDodge W.F. Schierenbeck Xtek, Inc. R.G. Smith . Philadelphia Gear Corporation R. Tarneja . Peerless-Winsmith, Inc. F.C. Uherek Fiender Corporation J.J. Vielhauer The Cincinnati Gear Company ASSOCIATE MEMBERS D. Behike Twin Disc, Inc. R.E. Brown Caterpillar, inc. R . Z . Johnston University of Maine S. Miller . The Cincinnati Gear Company C. Mischke Iowa State University A.E. Phillips Rockwell AutomationDodge A. Williston . Dorris Company V -,-,- ANSUAGMA 6001497 AMERICAN NATIONAL STANDARD (This page is intentionally blank) vi -,-,- - AMERICAN NATIONAL STANDARD ANSIIAGMA 6001 -D97 American National Standard - Design and Selection of Components for Enclosed 1 Scope Gear Drives This standard provides an acceptable practice for the design and selection of components for enclosed gear drives. Fundamental equations provide for the proper sizing of shafts, keys, and fasteners based on stated allowable stresses. Other components are discussed in a manner to provide an awareness of their function or specific requirements. This stan- dard applies to the following types of commercial and industrial enclosed gear drives, individually or in combination: spur, helical, herringbone, bevel and worm. 1.1 Exceptions The equations in this standard are not applicable when gear drives are subjected to vibratory condi- tions where there may be unpredictable fatigue failure. The procedure for design or selection of the specific gear components is varied and complex and is beyond the scope of this standard. Designers must refer to the specific rating or enclosed drive standards for this aspect of drive design. 1.2 Intended use The equations and values presented provide a general approach to design. Deviations from the methods and values stated in this standard may be made when justified by experience, testing, or more specific analysis. It is intended for use by experienced gear designers capable of selecting reasonable values based on their knowledge of the performance of similar designs and the effect of such items as lubrication, deflection, manufacturing toler- ances, metallurgy, residual stresses, and system dynamics. It is not intended for use by the engineering public at large. 2 Definitions and symbols The symbols and definitions used in this standard may differ from those i n other AGMA standards. The user should not assume that familiar symbols can be used without a careful study of the applicable section( and equation). 2.1 Definitions The terms used, wherever applicable, conform tothe following standards: AGMA 904496, Metric Usage A N S I Y10.3-1968, Letter Symbols for Quantities Used in Mechanits o f Solids ANSI/AGMA 1012-F90, Gear Nomenclature, ùefìnitions of Terms with Symbols 2.2 Symbols The symbols used in this standard are shown in table 1. SI units of measure are shown in parentheses in table 1 and in the text. Where equations require a different format or constant for use with SI units, a second expression is shown after the first, indented, in smaller type, and with ' M “ included in the equation number. Example: Wf FP , - 2 Sie = 0.785 (D - y) , . (70) .( 70M) - WfFP Ste - 2 0.785(0 - 0.9382P) lhe second expression uses SI units. 3 Design conditions This standard should be used in conjunction with appropriate current AGMA standards. When the 1 -,-,- ANWAGMA 6001 -D97 AMERICAN NATIONAL STANDARD operating conditions are known, each component of the drive shall be designed to meet those conditions. When operating conditions are not known, all load carrying components of the drive shall be designed to support the stated mechanical rating of the drive for continuous duty based on a unrty service factor (1 .O). External loads must be considered as acting in directions and rotations producing the most unfavor- able stresses unless more specific information is available. Due allowances must be made for peak loads. For enclosed drives designed to operate under specific conditions such as load, speed, duty cycle and l i , components may be selected accordingly. Table 1 - Symbols used in equations Term Coefficient Compressive area of key in keyway Shear area Cross sectional area Distance from support to concentrated load Coefficient Coefficient Fastener nominal diameter Shaít diameter adjacent to section being analyzed Shaft inside diameter Shaft outside diameter Modulus of elasticity Concentrated load Peak load factor Fatigue safety factor Peak load safety factor Allowable stress to yield strength factor Modulus of rigidity Brinell hardness number Radial step Second area moment o f cross section Second polar moment of area Second polar moment of area o f nth section of shaft Constant Theoretical stress concentration factor in bending =astener torque coefficient 'atigue strength modification factor Surface finish factor Size factor 3eliabiltty factor remperature factor -¡fe factor Wodtfyhg factor for stress concentration Miscellaneous effects factor -ength of shaft -ength o f the nth section o f shaft 3ending moment 2oefficient Uumber o f stress cycles Units in2 (mm2) in2 (mm2) in2 (mm2) in (mm) - - - in (mm) in (mm) in (mm) in (mm) Ib/ir? (N/mm2) Ib (NI - - - - lb/i$ (N/mm2) HB in (mm) in4 (mm4) in4 (mm4) in4 (mm4) - - - - - - - - - - - in (mm) in (mm) Ib in (Nm) - - First referenced Fig 4 Eq 68 Eq 69 Eq 63 Eq 46 Fig 4 Eq 37 Eq 70 Fig 8 Eq 6 Eq 6 Eq 46 Eq 46 Eq 5 Eq 1 Eq 2 Eq 5 Eq 41 Eq 30 =ig 8 E q 46 E q 41 : q 8 E q 38 fq 71 fq 44 : q 34 : q 35 : q 35 : q 35 : q 35 : q 35 1q 35 : q 35 : q 44 : q 7 E q 37 :a 37 E q 41 (contin S, is modified fatigue strength, Ib/in2 (N/mm2); a, is Von Mises mean stress, Ibfin2 (Nimm?; J; is tensile yield strength, Ib/in2 (N/mm2); Fsf is fatigue safety factor. - This equation can be rewritten to solve for the fatigue safety factor. . . . (4) L J For the design to be considered acceptable for fatigue condition, the resutting fatigue safety factor, Fs, must be equal to or greater than 1 .O. 4.3 Peak load safety factor The following peak load analysis equation i s used to solve for the peak load safety factor: . . . (5) Stress curve associated with equation 5 u v) c v) Stress curve associated Mean stress Figure 1 - Design criteria O * Numbers in brackets throughout the text, 1, refer to publications listed in annex G. 5 ANSIIAGMA 6001 4 9 7 AMERICAN NATIONAL STANDARD where FsP is peak load safety factor; FYa i s allowable stress to yield strength factor; 4 is tensile yield strength, Ibh? (N/mm?; Fp is peak load factor; ototal is Von Mises total stress, Ib/in2 (N/mm2). CAUTION: Equation 5 is based on a ductile material. For purposes ofthis standard, a material is considered dudle if the tensile elongation ofthe core material is a i least 10%. For nonductile materiais, the efFects of stress concentration should be considered. See 4.5.1. If God includes stresses which are not a function of load, such as stress resulting from the weight of components or stress resulting from shrink fit of components, FsP may be conservative. Consider- ations may be given to only applying Fp to those stresses of For the design to be considered acceptable for peak load condition, the resulting peak load safety factor, FsP, must be equal to or greater than 1 .O. The safety factors are to be chosen based on experience and engineering judgement. 4.3.1 Allowable stress to yield strength factor, The allowable stress to yield strength factor is to provide conservatism over the stress resulting from expected peak load conditions and variations in the tensile yield strength. Values between 0.66 and 0.80 have traditionally been employed for this variable. Unless otherwise agreed upon, a value of 0.75 is recommended. 4.3.2 Peak load factor, Fp The peak load factor accounts for momentary peak loads over the unity ser