ISO INTERNATIONAL STANDARD 8667 Second edition 1992-10-01 Commercial vehicles and buses -.-- Cross-tooth gearbox flanges, type T Vehicules utilitaires et autobus - Brides de boites de vitesses a dents croisees, type T Referencenumber ISO 8667:1992(E) ISO 8667:1992(E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (lsO member bodies). The work of preparing International Standards is normally carried out through iso technical cornmittees. 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, aiso take part in the work. iso collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical 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. Internationai Standard iso 8667 was prepared by Technical Committee ISo/TC 22, Road vehicles, Sub-Committee SC 15, Interchangeability of components of commercial vehicles and buses. This second edition cancels..andreplaces the first edition (IsO 8667:1986), of which it constitutes a technical revision. IsO 1992 All rights reserved. No part of this publication may be reproduced or utilized in any fortn or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case Postale 56CH-1211 Geneve 20·Switzerland Printed in Switzerland ISO 8667:1992(E) Introduction 0.1 Gearbox flanges of types A and s. as specified in Iso 7646:1986. Commercial vehicles and buses -- Gearbox flanges -. Type A and Is0 7647:1986. Commercial vehicles and buses -- Gearhox flanges - Typc respectively. are designed for forcc-locking (friction) torque size of the flange and the bolts. As static or dynamic torque loads in- crease, however. a point is reached when these are inadequate, and there is a need forform-locking components. Increasing problems are being encountered with the flange joint in the assembly of drive shafts for heavy lorries. as power tools cannot be used because of space limitations, and because the large bolts, M16 type, have to be tightened steadily to a torque loading of about 30o N-m forexample. With special vehicles it may also be necessary to replace the engine. transmission units or axles in the shortest possible time, but this can be impracticable with a conventional flange joint which has, for exam- ple.ten M16 bolts. 0.2 This form-locking flange joint has been developed to avoid the need to increase the size of the flange or bolts while achieving the re- quired performance or to simplify assembly. Initially, a flange joint with spiral bevel-type teeth was developed but this is expensive to manufacture. The flange joint specified in this Inter- national Standard overcomes the problems described above. It requires only four holts which are smaller than comparable flanges of conven- tional construction, and the alignment of the drive shaft is not dependent on them. The drive shaft flange and the transmission flange centre themselves through the groups of teeth which intersect at 7o°; this im- proves alignment. and play, which occurs in conventional joints. is eliminated. As the drive is transmitted through the teeth, the axial force arising uncler torque loading. which must be carried by the bolts, is relatively low. A further feature is that jamming between flanges during dismantling is prevented. 0.3 The teeth can be produced on a universal milling machine with special cutters for short production runs. while for mass production the use of a surface broaching machine is envisaged. The simple tooth fo