ANSI/AGMA ISO 1328- 1(ISO 1328--1:1995 IDT) AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328- 1 Cylindrical Gears - ISO System of Accuracy - Part 1: Definitions and Allowable Values of Deviations Relevant to Corresponding Flanks of Gear Teeth American National Standard Cylindrical Gears - ISO System of Accuracy - Part 1: Definitions and Allowable Values of Deviations Relevant to Corresponding Flanks of Gear Teeth ANSI/AGMA ISO 1328--1 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 quoted or extracted. Credit lines should read: Extracted from ANSI/AGMA ISO 1328--1, Cylindrical Gears -- ISO System of Accuracy -- Part 1: Definitions and Allowable Values of Deviations Relevant to Corresponding Flanks of Gear Teeth, with the permission of the publisher, the American Gear Manufacturers Association, 1500 King Street, Suite 201, Alexandria, Virginia 22314.] Approved November 17, 1999 ABSTRACT This standard contains the ISO system of accuracy relevant to corresponding flanks of individual cylindrical involute gears. It provides definitions for gear tooth accuracy terms, the structure of the gear accuracy system and the allowable values of pitch, profile and helix deviations. A normative annex for tangential composite tolerances and an informative annex for allowable values of profile form, profile slope, helix form and helix slope deviations are provided. Published by American Gear Manufacturers Association 1500 King Street, Suite 201, Alexandria, Virginia 22314 Copyright ã 1999 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: 1--55589--733--9 ii AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328--1 Contents Page Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Normative reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Symbols and abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Structure of the system of accuracy for gears . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Formulae for allowable values of gear deviations of accuracy grade 5 . . . . . . 7 Allowable values of gear deviations relevant to corresponding flanks . . . . . . . iv 1 1 1 6 7 8 8 Tables 1 2 3 4 Single pitch deviation, ¦ fpt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Total cumulative pitch deviation, Fp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Total profile deviation, F= . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Total helix deviation, Fβ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Figures 1 2 3 4 Pitch deviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Profile deviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Helix deviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tangential composite deviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3 5 6 Annexes A B Tolerances for tangential composite deviations . . . . . . . . . . . . . . . . . . . . . . . . . 17 Values of profile and helix form and slope deviations . . . . . . . . . . . . . . . . . . . . 21 Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 iii Therefore. Annexes B and C are for information only.Concepts of “mean measurement trace”.Relative magnitudes of elemental tolerances for a single grade are in a different proportion.Part 1: Definitions and Allowable Values of Deviations Relevant to Corresponding Flanks of Gear Teeth. “slope deviation” and “form deviation” are defined. “design profile”. Alexandria. Annex A forms an integral part of ANSI/AGMA ISO 1328--1. This version was approved by the AGMA membership in June 1999. if any. -.Tolerances are established by geometric mean values of relevant ranges of parameters in tables. the information in this standard covers similar subjects as covered in ANSI/AGMA 2000--A88.The “profile evaluation range” and “helix evaluation range”. Gear Classification and Inspection Handbook -Tolerances and Measuring Methods for Unassembled Spur and Helical Gears. Differences include. -. 1999. such that the smallest number represents the smallest tolerance.Accuracy grade numbering system is reversed. not by formulas. 1500 King Street. -- Runout is not included as one of the elements with a tolerance. -- The “K Chart” is not used for the permissible tolerance values. ANSI/AGMA ISO 1328--1 is an identical adoption of ISO 1328--1:1995. footnotes and annexes. Virginia 22314. It was first published on 1995--02--15 then corrected and reprinted 1997--02--01. It was approved as an American National Standard on November 17. in this document are provided for informational purposes only and are not to be construed as a part of ANSI/AGMA ISO 1328--1. iv . where the tolerances are applied. are defined for less flank area than in ANSI/AGMA 2000--A88. Cylindrical Gears -. -. that currently exists. Suggestions for improvement of this standard will be welcome.ISO System of Accuracy -. In general. Suite 201. but are not limited to: -. The user of this American National Standard is alerted that differences exist between it and ANSI/AGMA 2000--A88.ANSI/AGMA ISO 1328--1 AMERICAN NATIONAL STANDARD Foreword [The foreword. They should be sent to the American Gear Manufacturers Association. the user of ANSI/AGMA ISO 1328--1 must be very careful when comparing tolerance values formerly specified using ANSI/AGMA 2000--A88. -.] This standard was developed by ISO Technical Committee 60 as an International Standard with ANSI/AGMA participation. . . . . . . . D. . . Arrow Gear Company Consultant The Falk Corporation ZF Industries Gear Engineers. . Hofrichter . May . . . . Lake . . . Nanlawala . . . . .R. .R. .F. . . Gregory . .S. . . Inc. J.. . -. . Koshiol . . . . ASSOCIATE MEMBERS M. . H. Inc. M. . . . W. . . . . . Wasilewski . Matzo . .J. . Storm . L. of Newcastle--Upon--Tyne Eastman Kodak Company The Gear Works -. Xtek. Univ. S. Mahr Corporation Chairman Measuring Methods Section: R. R. . D. . . Incorporated B. M. . . Inc. . . D.D. . B. Smith Company ACTIVE MEMBERS W. . R. . . C. R. . . Johnson . . Inc. . . Cowley . . D. . . . Senkfor . Cowan . . G. . Inc. D. . . Inc. Considine . W. Glasener . J. . A. . . . . Considine . S. . . . Brad Foote Gear Works. . Brown . Octrue . . . B. . Focus Tech. Price . . . . . . Smith . Harary .E. Waldie . . . . Marfice . . . . Lemanski . Cowan .L. . . Consultant Profile Engineering. Northwest Gears. .L. . . R. Liebherr Gear Technology Co. . . R. .A. . . B. . . Inc. . Inc. M. . . Fairfield Manufacturing Co. Inc. M. . . . Mahr Corporation The Horsburgh & Scott Co. . . D. Invincible Gear Company G. Pennell . . T.J. T. Inc. .S. . . . . Michaels .E. The Falk Corporation Oliver Gear. Horwell . . Hamilton . T. . . The Gear Works -. . S. . E. McCarroll . Miller . Eaton Corporation Gear Products. . . . . . Gudates . Ramberg . . . . Milam . . . . . . . . J. Corp. Kosal . . . . . . M. Sundstrand Corporation Amarillo Gear Company The Cincinnati Gear Co. . Lawson . . M. Grana . Bradley . Cox . . J. . . .Seattle. Fassler AG Lockheed Martin Energy Sys. . Zwart .J. . Klemm . . Columbia Gear Corp. .Seattle. Laskin . Precision Gear Company PMI Food Equipment Group Consultant Philadelphia Gear Corporation Arrow Gear Company Frorest City Gear Company Caterpillar. Luetkemeier J. Considine Associates Considine Associates Eaton Corporation M&M Precision Systems Corp. . Caterpillar. McVittie . H. J. . McNamara . . . . .Gear Mfg & Met. Okamoto . . . The Gleason Works Caterpillar.J.AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328--1 PERSONNEL of the AGMA Inspection and Handbook Committee Chairman Classification Section: E. D. Antosiewicz . . . . Regal--Beloit Corporation NIST Consultant Brown & Sharpe Mfg. . Barron . . . . . . . . . . D. . Rychlinski .E. Choiniere . . . Lindley . . . . . Inc. . . .H. .A. Inc. . Shariff . . . . Penn state University v . Ltd.Z. . . . . . . Henriot .S. .A. . Inc. E.A. . . Clatworthy . . T. . K. . G.K. .M. . . .A. . R. . Dick . . Inc. . P. V. . . . . . . . J. Green . .G. I. . . . Smith . . . . . . Heinrich .E. . . . Incorporated The Gleason Works Xtek.E. . Dodds . . M. Rockwell Automation/Dodge Caterpillar. National Broach & Machine Co. . . . T. F. IIT Research Institute CETIM Nippon Gear Company. . P. . . Caterpillar.R. .C. . . . . . . . . Young . . . . ) vi .ANSI/AGMA ISO 1328--1 AMERICAN NATIONAL STANDARD (This page is intentionally left blank. For the symbols not explained in this clause. Cylindrical gears -.1. it does not cover gear pairs as such.Code of inspection practice -. and parties to agreements based on this part of ISO 1328 are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. between the actual length and the theoretical length of the relevant arc.) It is strongly recommended that any user of this part of ISO 1328 be very familiar with the methods and procedures outlined in ISO/TR 10064--1. defined on a circle concentric with the gear axis at approximately mid--depth of the tooth. constitute provisions of this part of ISO 1328. Annex A gives formulae for tolerances for tangential composite deviations which are also criterions of ISO quality. Generally. 3. If for special applications (e. it is equal to the algebraic sum of the single pitch deviations of the same k pitches.g.) In theory. allowable values of deviations Fpk apply to sectors of which the number of pitches (k) ranges from 2 to the number nearest to z/8. Annex B provides values on profile and helix form and slope deviations which sometimes serve as useful information and evaluation values but are not mandatory inspection items. At the time of publication. 3 Definitions 1 Scope This part of ISO 1328 establishes a system of accuracy relevant to corresponding flanks of individual cylindrical involute gears. the structure of the gear accuracy system and the allowable values of pitch deviations.1 Pitch deviations This part of ISO 1328 applies only to each element of a toothed wheel taken individually. Use of techniques other than those of ISO/TR 10064--1 combined with the limits described in this part of ISO 1328 may not be suitable.ISO System of Accuracy -Part 1: Definitions and Allowable Values of Deviations Relevant to Corresponding Flanks of Gear Teeth The following standard contains provisions which. Hence. NOTE 1 Unless otherwise specified. (See figure 1. 3. 1 .1..1 single pitch deviation (fpt): Algebraic difference between the actual pitch and the corresponding theoretical pitch in the transverse plane.2 cumulative pitch deviation (Fpk): Algebraic difference over any sector of k pitches. evaluation of Fpk is limited to sectors not larger than one--eighth of the circumference. the relevant value(s) of k should be specified.Part 1: Inspection of corresponding flanks of gear teeth. 3. Members of IEC and ISO maintain registers of currently valid International Standards. ISO/TR 10064--1:1992. but are not mandatory inspection items. All standards are subject to revision. It specifies appropriate definitions for gear tooth accuracy terms. the edition indicated was valid. (See figure 1. evaluation of Fpz/8 is sufficient. total profile deviations and total helix deviations.AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328--1 American National Standard -- 2 Normative reference Cylindrical Gears -. For the purposes of this part of ISO 1328. through reference in this text. the following definitions apply. or high speed gears) smaller sectors are also to be checked. see clause 4. 2. For the remaining 8% of LAE. 3. It is represented by the total amplitude of the cumulative pitch deviation curve.2. NOTE 3 For analysis of the profile form deviation.2 active length (LAE): That part of the usable length which is related to the active profile.2 Profile deviations 3. the tolerance shall be three times the tolerance specified for the evaluation range Lα.1.Pitch deviations 2 .ANSI/AGMA ISO 1328--1 AMERICAN NATIONAL STANDARD 3. Toward the root of the tooth. the design profile traces are shown as chain--dotted lines. Unless otherwise specified. Depending on the design. its length is equal to 92% of the active length LAE. NOTE 4 In a profile diagram. point E is the start of the active profile of engagement with a rack having standard basic rack tooth proportions. b) unless otherwise specified. 3.1.2. +fpt pt k ¢ pt +Fpk theoretical actual In this example Fpk = Fp3 Figure 1 -.2.) NOTE 2 It is the responsibility of the gear designer to assure that the profile evaluation range is adequate for the application.4 design profile: A profile consistent with the design specification.1.2. Towards the tooth tip.1 usable length (LAF): Difference between the lengths of two transverse base tangents. (See figure 2. Towards the root of the tooth.1 profile deviation: Amount by which an actual profile deviates from the design profile. the usable length is limited by the tooth tip. extending from point E. it has the same limit as the usable length (point A).1. When not otherwise qualified. 3. 3.3 profile evaluation range (Lα): That part of the usable length to which the tolerances of the specified accuracy grade shall apply. evaluations a) and b) are based on the mean profile trace defined in 3. the active length extends to the endpoint E of the effective contact with the mating gear (start of the active profile).3 total cumulative pitch deviation (Fp): Maximum cumulative pitch deviation of any sector (with k = 1 up to k = z) of the corresponding flanks of a gear.1. It is in the transverse plane and normal to the involute profile.1. for minus deviations. which is the zone near the tip expressed by the difference between LAE and Lα. the usable length is limited either by the beginning of the root fillet or by the undercut (point F). If the mating gear is unknown. the following evaluation rules apply for the total profile deviation and the profile form deviation: a) excess material (plus deviation) which increase the amount of deviation shall be taken into account. 3.5. of which one extends from the base circle to the outer limit and the other extends from the base circle to the inner limit of the usable profile. by the start of tip chamfer or tip rounding (point A). the profile trace of an unmodified involute generally appears as a straight line.2. In figure 2. it is the profile in a transverse plane. the sum of the squares of deviations of the actual profile trace from the mean profile trace is minimal.1. Thus.Profile deviations 3. within the evaluation range. 3 . NOTE 5 This profile is an aid in the determination of ffα [figure 2b) ] and fHα [figure 2c)]. This is to be so done that.2.5 mean profile of a measured flank: A trace determined by subtracting from the ordinates of the design profile trace the corresponding ordinates of a straight--line gradient.AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328--1 Key i) Design profile: Actual profile: unmodified involute with minus material deviations in the reduction zone ii) Design profile: Actual profile: modified involute (example) with minus material deviations in the reduction zone iii) Design profile: Actual profile: modified involute (example) with excess of material in the reduction zone ROOT E F + fHα LAE LAF A ffα -Lα LAE LAF A LAF E A ffα fHα + + Lα-- Lα-- -Lα LAE LAF LAE LAF LAE LAF a) Total profile deviation E F Lα LAE LAF E F + -- -Lα LAE + Fα A E F + A iii) LAE LAF fHα Fα LAE LAF E F + -Lα -Lα Lα ii) ROOT E F TIP A + ffα -- A ROOT E F TIP A + Fα TIP A i) : Mean profile : Actual profile : Design profile b) Profile form deviation E F c) Profile slope deviation Figure 2 -. the position and the gradient of the mean profile trace is found by the “least--squares method”. which are each placed with constant separation from the mean helix trace. the trace of an unmodified helix generally appears as a straight line.4 helix slope deviation (fHβ): Distance between two design helix traces which intersect the mean helix trace at the endpoints of the evaluation range Lβ.4 Tangential composite deviations 3. Thus.3 design helix: A helix consistent with the design specifications. the design helix traces are shown as chain--dotted lines.1.3.2. NOTE 8 In a helix diagram. In figure 3.] 3. the position and the gradient of the mean helix is found by the “least--squares method”.1. shortened at each end by the smaller of the following two values: --5% of the facewidth.3. which are each placed with constant separation from the mean profile trace.4. excluding the tooth end chamfers or roundings.3 Helix deviations 3.1. evaluations a) and b) are based on the mean helix trace defined in 3. within the evaluation range.1. [See figure 2b). NOTE 7 For the analysis of helix form deviation. the “length of trace”.3.3.] 3. 4 AMERICAN NATIONAL STANDARD 3.1.2 total profile deviation (Fα): Distance between two design profile traces which enclose the actual profile trace over the evaluation range Lα. measured in the direction of the transverse base tangent. 3.3 helix form deviation (ffβ): Distance between two facsimiles of the mean helix trace. [See figure 2c). 3. subject to the provisions of 3. the following evaluation rules apply for the total helix deviation and the helix form deviation: a) excess material (plus material deviation) which increases the amount of deviation shall be taken into account. the sum of the squares of the deviations of the actual helix trace from the mean helix trace is minimal. b) unless otherwise specified. determined by subtracting from the ordinates of the design helix trace the corresponding ordinates of a straight--line gradient.3. the tolerance shall be three times the tolerance specified for the evaluation range Lβ. In the relevant end zones.2. This is to be so done that.2 helix evaluation range (Lβ): Unless otherwise specified.) .1.3.2. the tested product gear being turned through one complete revolution. [See figure 3b).2.1 length of trace: Length proportional to the facewidth of the gear.4 mean helix of a measured flank: A trace.3. 3. for minus material deviations.2. NOTE 6 It is the responsibility of the gear designer to assure that the helix evaluation range is adequate for application. [See figure 3c). NOTE 9 This helix is an aid in the determination of the deviations ffβ [figure 3b)] and fHβ [figure 3c)].1 total tangential composite deviation (F¢¢i): Maximum difference between the effective and theoretical circumferential displacements at the reference circle of the gear under inspection.3. NOTE 10 During the inspection process.3. subject to the provisions of 3. so as to enclose the actual profile trace over the evaluation range Lα.] 3.2.3.4.3.2 tooth--to--tooth tangential composite deviation (f¢¢i): Value of the tangential composite deviation over a displacement of one pitch. [See figure 2a).1. so as to enclose the actual helix trace over the evaluation range Lβ.3. 3. [See figure 3a).ANSI/AGMA ISO 1328--1 3.1. when meshing with a master gear.] 3. subject to the provisions of 3.1 helix deviation: Amount.3 profile form deviation (ffα): Distance between two facsimiles of the mean profile trace.2. contact takes place on only one set of corresponding flanks (figure 4). (See figure 4.] 3.3. 3.2 total helix deviation (Fβ): Distance between two design helix traces which enclose the actual helix trace over the evaluation range Lβ. subject to the provisions of 3.4 profile slope deviation (fHα): Distance between two design profile traces which intersect the mean profile trace at the endpoints of the evaluation range Lα. by which an actual helix deviates from the design helix.] 3.4.1. or the length equal to one module. Helix deviations 5 .AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328--1 Key i) Design helix: Actual helix: unmodified helix with minus material deviations in the reduction zone ii) Design helix: Actual helix: modified helix (example) with minus material deviations in the reduction zone iii) Design helix: Actual helix: modified helix (example) with excess of material in the reduction zone I II fHβ -Lβ b b b I II I II + II fHβ + -- ffβ -- -- Lβ Lβ Lβ b b b I I II + -- -- Lβ b a) Total helix deviation I II + ffβ Fβ + Fβ + -Lβ I iii) II -Lβ i) ii) I II + ffβ Fβ + Lβ II + fHβ I : Mean helix : Actual helix : Design helix -Lβ b b b) Helix form deviation c) Helix slope deviation Figure 3 -. 1) 6 1 25 .1 Gear data and gear terms (lengths in millimetres) Q Accuracy grade ελ Total contact ratio I Reference face II Non--reference face 4.Tangential composite deviations _____________ These deviations can be plus or minus.ANSI/AGMA ISO 1328--1 AMERICAN NATIONAL STANDARD 4 Symbols and abbreviations 4. 1 Figure 4 -.2 Gear deviations (in micrometres) b Facewidth d Reference diameter k Number of successive pitches m Module pt Transverse pitch z Number of teeth A Beginning point of chamfer or tip rounding E Start of active profile F LAE Profile form deviation ffα Helix form deviation ffβ fHα 1) Profile slope deviation fHβ1) Helix slope deviation f ¢i fpt1) Tooth--to--tooth tangential composite deviation Single pitch deviation Start of usable profile F¢i Total tangential composite deviation Active length (of base tangent) Fp Total cumulative pitch deviation 1) LAF Usable length (of base tangent) Fpk Lα Profile evaluation range Fα Cumulative pitch deviation Total profile deviation Lβ Helix evaluation range Fβ Total helix deviation F′i f ′i One revolution of test specimen 1 25 23 21 19 17 15 13 11 9 7 5 3 Tooth No. 2 to 5. they are rounded to the nearest integer number. 5. When a statement concerning required accuracy is made in documents. particularly when less than 5 mm.4 Rounding rules Values given in tables 1 to 4 are rounded versions of values calculated using the formulae in clause 6. 5. Unless otherwise specified. m 0. without taking into account tooth tip and tooth end chamfers. d 5/20/50/125/280/560/1 000/1 600/2 500/ 4 000/6 000/8 000/10 000 b) for the module (normal module). If greater than 10 mm. actual gear data may be substituted in the formulae. Alternatively. understood to be nominal values. 5. 6. reference to ISO 1328--1 or ISO 1328--2. module m and facewidth b are. The required value for any accuracy grade can be determined by multiplying the unrounded calculated value for accuracy grade 5 by 20. i. as appropriate.. shall be included. as appropriate. These values are calculated with the formulae given in clause 6.5).4. the parameters. If less than 10 mm. The step factor between two consecutive grades is equal to 2. they are rounded to the nearest 0.5 Validity When in procurement documents the required gear accuracy grade corresponding ISO 1328--1 is stated without other indication. the actual module is 7. measurements are carried out at approximately mid--tooth depth and/or mid--facewidth. if not otherwise specified. 5.1. the measuring equipment shall be of sufficient accuracy to insure that the measurements of size can be repeated with the required accuracy. where Q is the accuracy grade number of the required value.5/6/10/16/25/40/70 c) for the facewidth. Measurements of the single pitch deviation.1 and 6.746 When gear data are not within the specified ranges or when agreed between purchaser and supplier. by agreement. profile and helix deviations are to be evaluated on both flanks of a minimum of three teeth approximately equally spaced around the gear.5 (Q -. for example.1 to 6. 7 .2 Allowable values for deviations The accuracy grade of a gear is evaluated by comparing measured deviations against the numerical values given in tables 1 to 4. fpt are required on both flanks of all teeth. working and non--working flanks of different accuracy grade may be specified and/or different accuracy grade may be specified for different deviations. b 4/10/20/40/80/160/250/400/650/1 000 When applying the formulae given in clause 6. With reference to the formulae in clause 6 and tables 1 to 4. d and b are to be introduced as the ANSI/AGMA ISO 1328--1 geometrical mean values of the relevant range limits and not as the actual values. However.e. 5.1 ISO system of accuracy The ISO system of accuracy comprises 13 accuracy grades of which grade 0 is the highest and grade 12 is the lowest degree of accuracy. If.2.5/2/3. If less than 5 mm. the required accuracy grade may be specified for the working flanks only.3 Ranges of parameters The lower and upper range limits areas follows (values are in millimetres): a) for the reference diameter.2. the range limits are m = 6 and m = 10.1 mm value or integer number. Allowable values for the cumulative pitch deviation Fpk for which no tables with numerical values are provided are to be calculated on the basis of 3. which apply for accuracy grade 5. m. that grade applies to deviations of all elements in accordance with 6.5 mm value or integer number.5 of this part of ISO 1328. values of each next higher (lower) grade are determined by multiplying (dividing) by 2. and allowable deviations are calculated with m = 6 × 10 = 7. Unless otherwise specified.AMERICAN NATIONAL STANDARD 5 Structure of the system of accuracy for gears 5. When tolerance values are small. they are rounded to the nearest 0. 3m + 0. is calculated from F pk = f pt + 1. is calculated from F = = 3.1 Single pitch deviation. are given in annexes A and B respectively. 8 AMERICAN NATIONAL STANDARD .6 Parameters m. Fpk.6 ( k − 1 )m 6.2 Cumulative pitch deviation.2 m + 0.ANSI/AGMA ISO 1328--1 6 Formulae for allowable values of gear deviations of accuracy grade 5 NOTE 11 Symbols are as defined in clause 4.22 d + 0. Fα.4 Total profile deviation.25 d + 7 6. is calculated from F p = 0. Fp. is calculated from F β = 0.5 Total helix deviation. 7 Allowable values of gear deviations relevant to corresponding flanks See tables 1 to 4.4 d + 4 6. fpt.2 6.63 b + 4.3m + 1. and for recommended tolerances for profile and helix form and slope deviations. d and b are introduced into the formulae as geometrical mean values of relevant range limits as defined in 5. is calculated from f pt = 0.3 Total cumulative pitch deviation.4.7 6.1 d + 0.3 and 5. 6. Fβ. Formulae for tolerances for tangential composite deviations. ¦ fpt 9 .AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328--1 Table 1 -.Single pitch deviation. ANSI/AGMA ISO 1328--1 10 AMERICAN NATIONAL STANDARD . Total cumulative pitch deviation.AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328--1 Table 2 -. Fp 11 . ANSI/AGMA ISO 1328--1 12 AMERICAN NATIONAL STANDARD . Fα 13 .AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328--1 Table 3 -.Total profile deviation. ANSI/AGMA ISO 1328--1 14 AMERICAN NATIONAL STANDARD . Fβ 15 .Total helix deviation.AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328--1 Table 4 -. ANSI/AGMA ISO 1328--1 16 AMERICAN NATIONAL STANDARD . 1 by the factor K (K is as defined in A.2.3 + f pt + F = i. with a certain backlash) whilst contact is restricted to only one set of corresponding flanks. the rules stated in clause 5 shall apply for (f ¢i /K) ¢ K. the calculation of εγ is to be carried out using the smaller facewidth. Definitions of the tooth--to--tooth tangential composite deviation and of the total tangential composite deviation are given in 3.2 Formulae for tolerances of accuracy grade 5 NOTE 12 The symbols used are as defined in clause 4. can sometimes be applied to replace some of the other inspection processes.2. In these cases. the method.2 Áγ + 4 Áγ for Á γ < 4 K = 0..3m + 3.1 General Unless otherwise specified in procurement documents.e. f ′ i = K9 + 0.2. by applying the same calculation rules as those stated in clause 5.AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328--1 Annex A (normative) Tolerances for tangential composite deviations A. by applying a light but sufficient load. special agreements on test conditions and evaluation on recorded diagrams are advisable. Tolerances for these deviations are therefore not included in the main body of this part of ISO 1328. Tolerance values for tooth--to--tooth tangential composite deviations f ¢i are calculated either by multiplying the numerical values f ¢i /K given in table A.2. A.1) or with the formulae given in A. A.2 m + 0. f ¢i. the effective values of εγ and K under test conditions can be so strongly affected that these must be taken into account when assessing the results of measurement. If the profile and/or the helix of the teeth are extensively modified.34 d where K = 0. Rules for calculating the values of different accuracy grades and for rounding of deviation values are the same as those stated in clause 5. When checking the tangential composite deviation accuracy grade. for any other accuracy grade.e. However. the measurement of tangential composite deviations is not mandatory.1 for accuracy grade 5 and. For rounding the deviation values. F¢i.2. A.2 Total tangential composite deviation. is calculated as follows: F′ i = F p + f ′ i 17 . Tolerance values for total tangential composite deviations F¢i for accuracy grade 5 are calculated with the formula given in A. is calculated as follows: f ′ i = K 4.1 Tooth--to--tooth tangential composite deviation. preferably accompanied by a check of tooth contact.2. the gear to be inspected shall mesh with a master gear at an appropriate centre distance (i. when agreed between the supplier and purchaser.4..4 for Á γ ≥ 4 If the facewidths of the product gear and master gear are different. 1 -.ANSI/AGMA ISO 1328--1 AMERICAN NATIONAL STANDARD Table A.Values of the quotient f ¢i/K 18 . AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328--1 19 . ANSI/AGMA ISO 1328--1 AMERICAN NATIONAL STANDARD (This page is intentionally left blank.) 20 . 17 d + 0. none are provided as normative elements in this part of ISO 1328.5 B.2. and helix slope deviation fHβ. are provided for informational purposes only and should not be construed as a part of ANSI/AGMA ISO 1328--1.1 General Since the form and slope deviations of profiles and helices are not individually subject to mandatory tolerances.1 to B. are calculated from f fβ = f Hβ = 0.3 and 3.AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328--1 Annex B (informative) Values of profile and helix form and slope deviations [The foreword.4 and in 3. is calculated from f H= = 2 m + 0.Part 1: Definitions and Allowable Values of Deviations Relevant to Corresponding Flanks of Gear Teeth. B.2.2 Profile slope deviation fH=.] B. is calculated from f f= = 2.3. Definitions of profile and helix form and slope deviations are given in 3.2. if any.2.2.5 B.1 Profile form deviation ff=.ISO System of Accuracy -. relevant values are given in tables B. footnotes and annexes.5 m + 0.07 d + 0.3. 21 . Cylindrical Gears -.45 b + 3 B.3 Helix form deviation ffβ.3 and 3.2.4 Rules for the calculation of form and slope deviation values of different accuracy grades and for rounding these values are the same as those stated in clause 5. However.2 Formulae for values of accuracy grade 5 B.14 d + 0.4.3. as form and slope deviations have a substantial influence on the performance characteristics of the gear. ff= = 22 .Profile form deviation.ANSI/AGMA ISO 1328--1 AMERICAN NATIONAL STANDARD Table B.1 -. AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328--1 23 . 2 -.ANSI/AGMA ISO 1328--1 AMERICAN NATIONAL STANDARD Table B. ¦ fH= = 24 .Profile slope deviation. AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328--1 25 . fHβ 26 . and helix slope deviation.ANSI/AGMA ISO 1328--1 AMERICAN NATIONAL STANDARD Table B.3 -.Helix form deviation. ffβ. AMERICAN NATIONAL STANDARD ANSI/AGMA ISO 1328--1 27 . 1) ISO 53: 1974. International gear notation -.Part 1: Geometrical definitions. Cylindrical gears for general and heavy engineering -.Basic rack. 2) ISO 54:1977. Cylindrical gears -. 3) ISO 701:1976. 5) ISO/TR 10064--2:1996. Cylindrical gears for general engineering and for heavy engineering -. runout.Symbols for geometrical data.ANSI/AGMA ISO 1328--1 AMERICAN NATIONAL STANDARD Bibliography The following documents are either referenced in the text of ANSI/AGMA ISO 1328--1. tooth thickness and backlash.Modules and diametral pitches. 28 .Code of inspection practice -.Part 2: Inspection related to radial composite deviations. Cylindrical Gears -.ISO System of Accuracy -.Part 1: Definitions and Allowable Values of Deviations Relevant to Corresponding Flanks of Gear Teeth or indicated for additional information. Glossary of gear terms -. 4) ISO 1122--1:1983. ALEXANDRIA.PUBLISHED BY AMERICAN GEAR MANUFACTURERS ASSOCIATION 1500 KING STREET. VIRGINIA 22314 .