ISO/TS TECHNICAL SPECIFICATION 6336-4 First edition 2019-01 Calculation of load capacity of spur and helical gears - Part 4: Calculation of tooth flank fracture load capacity Calcul de la capacité de charge des engrenages cylindriques d dentures droiteethelicoidale Partie 4: Calcul de la capacite de charge de la rupture en flanc de dent Reference number ISO/TS 6336-4:2019(E) ISO @ IS0 2019 IS0/TS 6336-4:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ ISO 2019 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IsO at the address below or Iso's member body in the country of the requester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +4122 749 0111 Fax: +41 22 749 09 47 Email: copyright@iso.org Website: www.iso.org Published in Switzerland ii @ IS0 2019 - All rights reserved IS0/TS 6336-4:2019(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. ..1 2 Normative references ..1 3 Terms, definitions, symbols and abbreviated terms. 3.1 Terms and definitions. .1 3.2 Symbols and abbreviated terms. 3.3 Definition of local contact point, CP, and material depth, y ..3 4 Definition of tooth flank fracture ..4 5 Basic formulae .5 5.1 .5 General 5.2 Maximum material exposure, AFF,max ..5 5.3 Local material exposure, AFF,cp(y) .6 Local occurring equivalent stress, Teff,cp(y) .7 6 6.1 General .7 6.2 Local equivalent stress without consideration of residual stresses, Teff,L,cp(y) .1 6.2.1 General. .7 6.2.2 Local normal radius of relative curvature, Pred,cP .8 6.2.3 Reduced modulus of elasticity, Er .8 6.2.4 Local Hertzian contact stress, pdyn,CP .9 6.3 Quasi-stationary residual stress, Teff,Rs(y) 20 6.3.1 General 20 6.3.2 Method A. 21 6.3.3 Method B 21 6.4 Influence of the residual stresses on the local equivalent stress, △teff,L,RS,cp(y) .21 Local material strength, Tpercp(y) .22 7 7.1 General 22 7.2 23 7.3 Material factor Kmaterial 23 7.4 Hardness depth profile, HV(y) .24 7.4.1 General 24 7.4.2 Method A. .24 7.4.3 Method B. .24 7.4.4 Method C1 .25 7.4.5 Method C2 ..25 Annex A (informative) Calculation of local equivalent stress without consideration of residual stresses, Teff,L,cp(y) ..27 Bibliography .28 @ IS0 2019 - All rights reserved iii