1、BRITISH STANDARD AUTOMOBILE SERIES BS AU 252:1993 ISO 8123:1991 Specification for Diametral pitch starter motor pinions for road vehiclesBSAU252:1993 This British Standard, having been prepared under the directionof the Automobile Standards Policy Committee, waspublished under the authorityof the St
2、andards Boardand comes into effect on 15July1993 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference AUE/13 Draft for comment 83/73908 DC ISBN 0 580 21877 5 Committees responsible for this British Standard The preparation of this British Standard was ent
3、rusted by the Automobile Standards Policy Committee (AUE/-) to Technical Committee AUE/13, upon which the following bodies were represented: British Railways Board Bus and Coach Council Department of Health Department of Transport Department of Transport (Transport Research Laboratory) Freight Trans
4、port Association Health and Safety Executive Institute of Road Transport Engineers Lloyds Register of Shipping Ministry of Defence Road Haulage Association Ltd. Society of Motor Manufacturers and Traders Ltd. Coopted members Amendments issued since publication Amd. No. Date CommentsBSAU252:1993 BSI
5、10-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope 1 2 Dimensions 1 Figure 1 1 Table 1 2 List of references Inside back coverBSAU252:1993 ii BSI 10-1999 National foreword This British Standard has been prepared under the direction of the Automobile Standar
6、ds Policy Committee. It is identical with ISO8123:1991Road vehicles Diametral pitch starter motor pinions, which was prepared by Technical Committee ISO/TC22 of the International Organization for Standardization (ISO) and in the development of which the United Kingdom played an active part. A Britis
7、h Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-reference International Standard Correspond
8、ing British Standard ISO 701:1976 BS 2519 Glossary for gears Part 2:1976 Notation (Identical) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 and 2, an inside back cover and a back cover. This standard has been updated (see copyright date) and ma
9、y have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BSAU252:1993 BSI 10-1999 1 1 Scope This International Standard specifies the diametral pitches, pressure angles, number of teeth and other tooth characteristics which are necessary to ensure i
10、nterchangeability of starter motor pinions used for starter motors mounted on reciprocating internal combustion engines for road vehicles. 2 Dimensions Detailed tooth limit dimensions and the base tangent length as the inspection value, W 2 , are given in Table 1 for diametral pitch starter motor pi
11、nions. NOTE 1The symbols, which are in accordance with ISO701:1976, International gear notation Symbols for geometrical data, are illustrated in Figure 1. Figure 1 BS AU 252:1993 2 BSI 10-1999 Table 1 Module, m a 2,1167 2,54 3,175 4,233 Diametral pitch, P b in 1 12 10 8 6 Pressure angle, 12 20 20 20
12、 Number of teeth, z 9 10 11 12 8 9 10 11 9 10 11 12 10 11 12 Addendum modification, coefficient, x 0,75 0,42 0,5 0,5 Tip diameter, d a max. min. 25,80 25,59 27,93 27,72 30,00 29,79 32,30 32,05 27,2 27,0 29,7 29,5 32,3 32,1 34,8 34,6 37,25 37,00 40,40 40,15 43,50 43,25 46,75 46,50 53,30 53,05 57,60 5
13、7,35 61,80 61,55 Root diameter, d f max. min. 17,70 17,27 19,50 18,98 21,60 21,08 23,75 23,23 17,4 17,1 19,9 19,6 22,5 22,1 25,0 24,6 25,1 24,7 28,3 27,9 31,4 31,0 34,6 34,2 38,1 37,7 42,3 41,9 46,6 46,2 Start of active profile, d NfE max. 18,7 20,76 22,84 24,9 19,2 21,6 24,09 26,56 27,07 30,19 33,2
14、7 36,41 40,41 44,57 48,79 End of active profile, d Na min. 25,49 27,62 29,69 31,95 26,9 29,4 32 34,5 36,85 40 43,1 46,35 52,9 57,2 61,4 Base tangent length, W 2 max. min. 10,48 10,43 10,49 10,44 12,26 12,18 12,30 12,22 12,33 12,25 12,37 12,29 15,55 15,46 15,59 15,50 15,63 15,54 15,68 15,59 20,79 20,
15、69 20,85 20,75 20,91 20,81 a b P is the number of teeth per inch reference diameter, in reciprocal inches. m 25,4 P - mmin 1 in 1 - =BSAU252:1993 BSI 10-1999 List of references See national foreword.BS AU 252:1993 ISO 8123:1991 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution
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