ISO-8123-1991.pdf
INTERNATIONAL STANDARD IS0 8123 First edition 1991-04-15 Road vehicles - Diametral pitch starter motor pinions Vdhicules routiers - Pignons de demarreurs B diametral pitch - - - Reference number IS0 8123:1991(E) IS0 8123:1991(E) Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing international Standards is normally carried out through IS0 technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with ISO, also take part in the work. IS0 collaborates closely with the International Eiectrotechnical Commission (IEC) on ail matters of eiectrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an Inter- national Standard requires approval by at least 75% of the member bodies casting a vote. International Standard IS0 8123 was prepared by Technical Committee iSO/TC 22, Road vehicles. 0 IS0 1991 All rights reserved. No part of this publlcatlon may be reproduced or utilized in any form or by any means, electronic or mechanical, lncludlng photocopylng and mlcrofllm, wlthout permission In writing from the publlsher. lnternatlonal Organlzatlon for Standardlzatlon Case Postale 56 l CH-1211 Geneve 20 l Switzerland Prlnted In Switzerland ii INTERNATIONAL STANDARD IS0 8123:1991(E) Road vehicles - Diametral pitch starter motor pinions 1 Scope 2 Dlmensions This international Standard specifies the diametral pitches, pressure angles, number of teeth and other tooth characteristics which are necessary to ensure interchangeability of starter motor pinions used for starter motors mounted on reciprocating internal Detailed tooth limit dimensions and the base tangent length as the inspection value, TV, are given in table 1 for dlametral pitch starter motor pinions. NOTE 1 The symbols, which are in accordance with IS0 701:1976, international gear notation - Symbols for combustion engines for road vehicles. geometrical data, are illustrated in figure 1. -,-,- Module, m 1) 2,1167 254 3,175 4,233 I / Diametrai pitch, P 2) in-1 12 10 8 6 1 Pressure angle, CL I I I I 0 12 20 20 20 1 I I , Number of teeth, z 9 10 11 12 8 9 10 11 9 IO 11 12 IO 11 12 0,75 Addendum modification, coef- ficient, x Tip diameter, d, max. 25,80 27,93 30,OO 32.30 27,2 29,7 32,3 34,8 37,25 40,40 43,50 46,75 53,30 57,60 61,80 min. 25,59 27,72 29,79 32.05 27,0 29,5 32,l 34,6 ,37,00 40,15 43,25 46,50 53,05 57.35 61,55 -I ! I Root diameter, df max. 17,70 19,50 21,60 23,75 17,4 19,9 22.5 25,O 25,l 28,3 31,4 34,6 38,l 42,3 46,6 & min. 17,27 18,98 21,08 23.23 17,l 19,6 22,l 24,6 24,7 27,9 31,0 34,2 37,7 41,9 46,2 Q -5 Start of active profile, dNfE max. 18,7 20,76 22,84 24,9 19,2 21,6 24,09 26,56 27,07 30,19 33,27 36,41 40,41 44,57 48,79 End of actrve profile, dNa min. 2549 27.62 29,69 31,95 26,9 29,4 32 34.5 36,85 40 43,l 46,35 52,9 57,2 61,4 Base tangent length, W, max. IO,48 10.49 12,26 12,30 12,33 12,37 15,55 15.59 15,63 15,68 20,79 20,85 20,91 min. 10,43 10,44 12.18 1222 1225 12,29 1546 15.50 1554 45.59 20,69 20,75 20.81 1) m= 2) P is the number of teeth per inch reference diameter, in reciprocal inches. -,-,- IS0 8123:1991(E) w2 - c Figure 1 3 IS0 8123:1991 (E) UDC 621.833.12:621.316.717:621.431.73 Descriptors: road vehicles, Internal combustion englnes, englne starters, plnlons, speclflcatlons, dlmenslons, tooth modulus, number of teeth. Price based on 3 pages -,-,-
