1、AGIA 2002-8 88 W 0687575 0003747 745 m ANSVAGMA 2002-888 ERRATA January, 1995 The following editorial corrections should be made to ANWAGMA 2002-888, Tooth Thickness Specification andMeasurement, (originally printed October 1988). These changes, discovered after publication, have not been made in th
2、e printing of this document. The changes are shown below. Users of ANWAGMA 2002-888 are encouraged to cut out these stickers and insert them in the standard. The equations can be placed over the existing equations. Page 29 L where J 8 I I I Pd =transverse standard diametral pitch; ; tl = maximum tra
3、nsverse tooth thick- ; t2 = transverse tooth thickness of the ; N1 I I I ness of the test gear at os, in (mm); 8 I l I master gear at $Isl in (mm); I I I I I I I = number of teeth in the test gear I N2 = number of teeth in the master gear. I -1- Copyright American Gear Manufacturers Association Prov
4、ided by IHS under license with AGMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ANSYAGMA lO(n-BS8 ERRATA July, 1992 The foilowing editorial corrections should be made to ANSYAGMA 2002-BS8, Tooth Thickness Specca- tion andMeaswement, (originally printed October 1
5、988). “hese changes, discovered after publication, wiil be made in the next printing, as shown below: PAGE ITEM CHANGE 10 Fig 3-1 The position of minimum and maximum backlash is shown on the specified circle, also 1/2 specified tolerance and 1/2 specification bands labeled correctly. 26 Fig 7-3 The
6、angle W,and the assumed form diameter, Do - 4a, indicated correctly. 29 Eq 8.2 The right hand bracket should be at ihe end, with the full equation reading, pnd (t1+f2)-“ Nl+N2 +inv#, , W8.2) 32 Table A-1 The last value in the table , for 64 inch center, should read 0.058. . -1- I Table A-1 I Pitch G
7、ean (inch vaiues) I Minimum Backiash,B min, for Coarse I I Minimum Center Distance, C, in I I pnd 2 4 8 16 32 64 I - - -1 I 18 0.005 0.006 - I 12 0.006 0.007 0.009 - - - I 8 0.007 0.008 0.010 0.014 - - I I 5 0.010 0.012 0.016 - - 0.014 0.016 0.020 0.028 - I 3 - - 0.021 0.025 0.033 - I I 2 i 1 1/4 -
8、- - 0.034 0.042 0.058 I l I - Copyright American Gear Manufacturers Association Provided by IHS under license with AGMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AGHA 2002-8 = 0687575 OOOL269 TL7 MAXIMUM CONDITION (MATING GEAR) i Il GREATEST BACKLASH li FOR TI
9、GHTEST CENTERS* i J -3 MAXIMUM EFFECTIVE SPECIFIED MAXIMUM TOOTH THICKNESS MINIMUM EFTEC“Ii% MlNiMUM MATERIAL CONDITION SPECIFIED MINIMUM 1/2 SPECIFIED TOLERANCE BAND, ELEMENTAL MEASUREMENT 112 SPECIFICATION BAND, COMPOSITE ACTION TEST * THIS FIGURE IS DRAWN AT THE POSITION OF TIGHTEST CENTER DISTAN
10、CE; IF CENTER DISTANCE IS INCREASED BACKLASH WILL INCREASE. I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I -2- Copyright American Gear Manufacturers Association Provided by IHS under license with AGMANot for ResaleNo reproduction
11、 or networking permitted without license from IHS-,-,-I t i I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I l I I I I +L max =2Jmj D SECTION A-A I I. Lmin I I I I I I I I I I ! I I I I I DIAMETER I 1 - D*- 4 Pnd TRANSVERSEPLANE i D, -4a y“/“ Do t I ASSUMD FORM DWTER -3- C
12、opyright American Gear Manufacturers Association Provided by IHS under license with AGMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AGMA 2002-8 D Ob87575 OOOL27L 675 D ANSIJAGMA 2002-B88 October 1988 I AMERICAN NATIONAL STANDARD I l l Tooth Thickness Specificat
13、ion and Measurement P B I I AGMA STANDARD Copyright American Gear Manufacturers Association Provided by IHS under license with AGMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AGMA 2002-8 Ob87575 0003272 501 Tooth Thickness Specification and Measurement (Revisio
14、n of AGMA 231.52-1975) AGMA 2002-BS8 Tables or other self-supporting sections may be quoted or extracted in their entirety. Credit lines should read: Extracted from AGMA 2002-B88 Standard, Tooth Thickness Specification and Measurement, with the permission of the publisher, the American Gear Manufact
15、urers Association, 1500 King Street, Suite 201, Alexandria, Virginia 22314.1 AGMA Standards are subject to constant improvement, revision or withdrawal as dictated by experience. Any person who refers to AGMA Technical Publications should be sure that the publication is the latest available from the
16、 Association on the subject matter. ABSTRACT This Standard establishes the procedures for determining tooth thickness measurements of external and internal cylindrical involute gearing. It includes equations and calculation procedures for the commonly used measuring methods. A specific tooth thickne
17、ss measurement limit can be established from the design thickness or from another tooth thickness measurement. The procedures can be entered with an established design tooth thickness, or with actual tooth thickness measurements. The effect of tooth geometric quality variations on tooth thickness me
18、asurements is discussed. Backlash information is provided in an appendix. Copyright O, 1988 American Gear Manufacturers Association 1500 King Street, Suite 201 Alexandria, Virginia, 22314 October, 1988 ISBN: 1-55589-523-9 ANSIiAGMA ii 2002-B88 Copyright American Gear Manufacturers Association Provid
19、ed by IHS under license with AGMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AGHA 2002-B m Ob87575 0003273 948 m Tooth Thickness Specification and Measurement FOREWORD This foreword, footnotes, and appendices, if any, are provided for informational purposes onl
20、y and should not be construed as part of American Gear Manufacturers Association Standard 2002-BS8, Tooth Thickness Specification and Measurement. This Standard presents calculation procedures for determining tooth thickness measurements of external and internal cylindrical involute gearing. It supe
21、rsedes AGMA 231.52, Inspection - Pin Measurement Tables for Involute Spur Gears. This Standard has been prepared to consolidate previously published AGMA tooth thickness information, to add more information on internal and helical gears and to add details on more measurement methods. Previous AGMA p
22、ublications have presented this information in tabular form, calculated for 1 DP and standard tooth proportions, with adjustment factors for nonstandard conditions. This Standard is arranged for direct calculation of the desired results, to eliminate the intermediate calculation steps and interpolat
23、ion previously required. The study of tooth thickness and backlash problems has been a major interest of gear technicians throughout the history of the industry. In the last fifty years, many clarifications and contributions have been made by men such as Buckingham, Candee, Leming, Vogel, and Wildha
24、ber. Their work is consolidated here, without further attribution, and the work of more recent contributors is added where it improves the presentation. The appendices provide further information on reasonable allowances for backlash and tooth thickness deviation, sample calculations, and informatio
25、n on four uncommon methods of measurement specified on some gear drawings. The treatment of the effects of tooth profile, pitch, lead, and runout deviations on tooth thickness measurement is new in this Standard. The information on backlash control is new in an AGMA Standard. It is based on AGMA Pap
26、er P239.14, Assured Backlash Control - The ABC System. l The first draft of this revision was made in February 1984. This version was approved by the AGMA membership on October 9, 1988 and as an American National Standard on October 17, 1988. Suggestions for the improvement of this Standard will be
27、welcome. They should be sent to the American Gear Manufacturers Association, 1500 King Street, Suite 20 1, Alexandria, Virginia, 223 14. ANSIJAGMA 2002-B8 8 Copyright American Gear Manufacturers Association Provided by IHS under license with AGMANot for ResaleNo reproduction or networking permitted
28、without license from IHS-,-,-AGHA 2002-8 m Ob87575 0003274 384 m Tooth Thickness Specification and Measurement PERSONNEL of the AGMA Committee for Inspection And Handbook Chairman: P. M. Dean, Jr. (Honorary Member) MEASURING METHODS Chairman: Editor: W. A. Bradley (Consultant) ACTIVE MEMBERS R. E. S
29、mith (R. E. Smith IF CENTER DISTANCE IS INCREASED BACKLASH WILL INCREASE. Fig 3-1 Tooth Thickness Transverse Plane MAXIMUM (SUBJECT GEAR) SPECIFIED / ANSI/AGMA 10 2002-B88 Copyright American Gear Manufacturers Association Provided by IHS under license with AGMANot for ResaleNo reproduction or networ
30、king permitted without license from IHS-,-,-AGMA 2002-B W Ob87575 0001287 T32 W Tooth Thickness Specification and Measurement tpmax = maximum transverse tooth thickness of pinion, at operating pitch radius, in (mm) = transverse circular pitch at operating (tightest) center distance, in (mm) P P = 2“
31、( i.e., the fact that the measurement over a pin is a function of than 4, makes it easy to detect small changes in tooth thickness. This is a common method of tooth thickness inspection. 6.2 Limitations of Measurement by Pins. Meas- urements are affected by deviations in pitch and profile. The follo
32、wing should be noted: - Pins on spur gears form line contacts - Balls on spur gears form point contacts - Pins and balls form point contacts on helical Therefore, deflection, because of the limited contact, can cause variation in readings and will vary with gaging pressure. gears. Micrometers are of
33、ten used to measure the 2 Numbers in brackets refer to the bibliography. ANSIIAGMA Fig 6-1 Tooth Thickness Measurement Over Pins dimension over pins. Even though the microme- ters may be graduated to 0.0001, the variation of the measurement among several operators may exceed O. O0 1. Balls must be h
34、eld exactly in the plane of ro- tation; a difficult task. Internal helicals cannot be measured with pins and are usually measured with balls. External helical gears with odd numbers of teeth should be measured with balls or with three pins between parallel planes. Both are difficult setups. The foll
35、owing is quoted from Analytical Me- chanics of Gears, by Earle Buckingham 2 Measurements over rolls on helical gears are very difficult to make with any great de- gree of accuracy unless definite precautions are taken. In many cases, a pair of cali- brated wedges, or rack teeth, make a much more rel
36、iable measurement for tooth thick- ness than do rolls. However rolls are often available when needed, while the special calibrated rack-tooth wedges may not be at hand. The measurement over rolls should 17 - 2002-B 8 8 Copyright American Gear Manufacturers Association Provided by IHS under license w
37、ith AGMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AGMA ZOOZ-B ob875i OOOIEW 172 m Tooth Thickness Specification and Measurement be made between parallel flat surfaces and not with a micrometer alone. When the roils are held in position on the gear by two para
38、llels, the two rolls will be on opposite sides of the gear, or diametrically opposite to each other, whether the number of teeth in the gear is odd or even. With odd num- bers of teeth, one roll may make contact near one edge of the gear while the other roll makes contact near the opposite edge of t
39、he face width. If an attempt is made to measure odd numbers of teeth over the rolls directly with a micrometer, one or both rolls will be tipped away from the correct plane of measurement, and any measured values so obtained are useless for any pur- pose. Ball-point micrometers may be used, but here
40、 the two balls must be definitely aligned in respect to the face of the gear blank. For example, the gear blank may be laid fiat on a surface plate, and the two ball points may be held against this same sur- face plate. Where balls are used, when odd numbers of teeth are involved, the calcula- tion
41、of the actual chordal measurement must include the offset condition or position in exactly the same way as the calculations are made for spur gears with odd numbers of teeth. Large micrometers are required for large gears. Measurements made over two pins or balls do not show functional tooth thickne
42、ss. Multiple readings taken around the gear should be averaged to find the mean. The mean value should be used in comparison of readings. The maximum reading, as previously stated, is probably closer to the functional tooth thickness, which is best measured by double flank testing. 6.3 Measurement M
43、ethods. It is important to use a measurement over pins 1 setup for which there is a suitable calculation method relating the measurement to the tooth thickness. For all types of spur and helical gears, there are measurement setups using pins or balls for which there are cor- responding geometrically
44、 exact calculation meth- ods. For external spur gears with even numbers of teeth, the measurement is made across the high points of two properly sized pins placed in diamet- rically opposed tooth spaces. In the case of spur gears with odd numbers of teeth, the tooth spaces used are those nearest to
45、diametrically opposed. Measurement over pins can also be per- formed on medium and small external helical gears. When the gear has an even number of teeth, the measurement technique is similar to that on spur gears. Although the two pins are not parallel, it is possible to position the anvils on a c
46、onventional micrometer so as to measure at dia- metrically opposite points. For helical gears with odd numbers of teeth, there are two techniques with geometrically exact calculation methods. One method uses three pins instead of two, but is limited to gears whose face widths are greater than their
47、axial pitches. This method also requires the use of a micrometer or other measuring instrument with an anvil of size greater than the axial pitch. The third pin is placed alongside one of the others so that the pair will be diametrically opposite the single pin. The wide anvil is positioned to span
48、the axial pitch dis- tance between the two adjacent pins and the sec- ond anvil, which need not be as wide, is posi- tioned to contact the single pin at a location half- way along the axial pitch distance. When properly positioned for measurement, all three pins will be in line contact with their re
49、spective parallel anvil surfaces. The measurement is twice the calcu- lated radius over one pin. The other method uses a single pin and is suit- able for any external helical gear, whatever the face width and whether the number of teeth is odd or even. The measurement over the single pin is made relative to the gear center line or rela- tive to the bore or other concentric cylindrical ref
