1、BSI Standards Publication PD ISO/TR 15144-1:2014 Calculation of micropitting load capacity of cylindrical spur and helical gears Part 1: Introduction and basic principlesPD ISO/TR 15144-1:2014 PUBLISHED DOCUMENT National foreword This Published Document is the UK implementation of ISO/TR 15144-1:201
2、4. It supersedes PD ISO/TR 15144-1:2010 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee MCE/5/-/15, Micropitting. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to i
3、nclude all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2014. Published by BSI Standards Limited 2014 ISBN 978 0 580 83309 0 ICS 21.200 Compliance with a British Standard cannot confer immunity from legal obligations. Th
4、is Published Document was published under the authority of the Standards Policy and Strategy Committee on 30 September 2014. Amendments issued since publication Date Text affectedPD ISO/TR 15144-1:2014 ISO 2014 Calculation of micropitting load capacity of cylindrical spur and helical gears Part 1: I
5、ntroduction and basic principles Calcul de la capacit de charge aux micropiqres des engrenages cylindriques dentures droite et hlicodale Partie 1: Introduction et principes fondamentaux TECHNICAL REPORT ISO/TR 15144-1 Second edition 2014-09-01 Reference number ISO/TR 15144-1:2014(E)PD ISO/TR 15144-1
6、:2014ISO/TR 15144-1:2014(E)ii ISO 2014 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2014 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or post
7、ing on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyr
8、ightiso.org Web www.iso.org Published in SwitzerlandPD ISO/TR 15144-1:2014ISO/TR 15144-1:2014(E) ISO 2014 All rights reserved iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 T erms, definitions, s ymbols, and units 1 3.1 Terms and definitions . 1 3.2 Symbols and u
9、nits 2 4 Definition of micr opitting . 4 5 Basic formulae 5 5.1 General . 5 5.2 Safety factor against micropitting, S 5 5.3 Local specific lubricant film thickness, GF,Y6 5.4 Permissible specific lubricant film thickness, GFP. 7 5.5 Recommendation for the minimum safety factor against micropitting,
10、S ,min. 7 6 Material parameter, G M8 6.1 Reduced modulus of elasticity, E r8 6.2 Pressure-viscosity coefficient at bulk temperature, M. 9 7 Velocity parameter, U Y.10 7.1 Sum of tangential velocities, v , Y. 10 7.2 Dynamic viscosity at bulk temperature, M11 8 Load parameter, W Y12 8.1 Local Hertzian
11、 contact stress p dyn,Y,Aaccording to Method A .12 8.2 Local Hertzian contact stress p dyn,Y,Baccording to Method B .12 9 Sliding parameter, S GF,Y.13 9.1 Pressure-viscosity coefficient at local contact temperature, B,Y14 9.2 Dynamic viscosity at local contact temperature, B,Y. 14 10 Definition of c
12、 ontact point Y on the path of c ontact .15 11 Load sharing factor, X Y.17 11.1 Spur gears with unmodified profiles 18 11.2 Spur gears with profile modification 19 11.3 Buttressing factor, X but,Y. 20 11.4 Helical gears with 1 and unmodified profiles 21 11.5 Helical gears with 1 and profile modifica
13、tion 22 11.6 Helical gears with 1 and unmodified profiles 23 11.7 Helical gears with 1 and profile modification 23 12 Contact temperature, B,Y.25 13 Flash temperature, fl,Y.26 14 Bulk temperature, M26 14.1 Mean coefficient of friction, m. 27 14.2 Load losses factor, H v. 29 14.3 Tip relief factor, X
14、 Ca. 29 14.4 Lubrication factor, X S. 32 Annex A (informative) Calculation of the permissible specific lubricant film thickness GFPfor oils with a micropitting test result according to FVA-Information Sheet 54/7 .33 Bibliography .35PD ISO/TR 15144-1:2014ISO/TR 15144-1:2014(E) Foreword ISO (the Inter
15、national Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has
16、been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical st
17、andardization. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in acco
18、rdance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Detai
19、ls of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an en
20、dorsement. For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information The committee re
21、sponsible for this document is ISO/TC 60, Gears, Subcommittee SC 2, Gear capacity calculation. This second edition cancels and replaces the first edition (ISO/TR 15144-1:2010), which has been technically revised. ISO/TR 15144 consists of the following parts, under the general title Calculation of mi
22、cropitting load capacity of cylindrical spur and helical gears: Part 1: Introduction and basic principles Part 2: Examples of calculation for micropittingiv ISO 2014 All rights reservedPD ISO/TR 15144-1:2014ISO/TR 15144-1:2014(E) Introduction This part of ISO/TR 15144 provides principles for the cal
23、culation of the micropitting load capacity of cylindrical involute spur and helical gears with external teeth. The basis for the calculation of the micropitting load capacity of a gear set is the model of the minimum operating specific lubricant film thickness in the contact zone. There are many inf
24、luence parameters such as surface topology, contact stress level, and lubricant chemistry. While these parameters are known to affect the performance of micropitting for a gear set, the subject area remains a topic of research and, as such, the science has not yet developed to allow these specific p
25、arameters to be included directly in the calculation methods. Furthermore, the correct application of tip and root relief (involute modification) has been found to greatly influence micropitting; the suitable values should therefore be applied. Surface finish is another crucial parameter. At present
26、, Ra is used but other aspects such as Rz or skewness have been observed to have significant effects which could be reflected in the finishing process applied. Although the calculation of specific lubricant film thickness does not provide a direct method for assessing micropitting load capacity, it
27、can serve as an evaluation criterion when applied as part of a suitable comparative procedure based on known gear performance. ISO 2014 All rights reserved vPD ISO/TR 15144-1:2014PD ISO/TR 15144-1:2014Calculation of micropitting load capacity of cylindrical spur and helical gears Part 1: Introductio
28、n and basic principles 1 Scope This part of ISO/TR 15144 describes a procedure for the calculation of the micropitting load capacity of cylindrical gears with external teeth. It has been developed on the basis of testing and observation of oil-lubricated gear transmissions with modules between 3 mm
29、and 11 mm and pitch line velocities of 8 m/s to 60 m/s. However, the procedure is applicable to any gear pair where suitable reference data are available, provided the criteria specified below are satisfied. The formulae specified are applicable for driving, as well as for driven cylindrical gears w
30、ith tooth profiles in accordance with the basic rack specified in ISO 53. They are also applicable for teeth conjugate to other basic racks where the virtual contact ratio is less than n= 2,5. The results are in good agreement with other methods for normal working pressure angles up to 25, reference
31、 helix angles up to 25, and in cases where pitch line velocity is higher than 2 m/s. This part of ISO/TR 15144 is not applicable for the assessment of types of gear tooth surface damage other than micropitting. 2 Normative references The following documents, in whole or in part, are normatively refe
32、renced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 53, Cylindrical gears for general and heavy engineering Standard basi
33、c rack tooth profile ISO 1122-1, Vocabulary of gear terms Part 1: Definitions related to geometry ISO 1328-1, Cylindrical gears ISO system of flank tolerance classification Part 1: Definitions and allowable values of deviations relevant to flanks of gear teeth ISO 6336-1, Calculation of load capacit
34、y of spur and helical gears Part 1: Basic principles, introduction and general influence factors ISO 6336-2, Calculation of load capacity of spur and helical gears Part 2: Calculation of surface durability (pitting) 3 T erms, d efinitions , s ymbols, and units 3.1 T erms and definiti ons For the pur
35、poses of this document, the terms and definitions given in ISO 1122-1, ISO 6336-1, and ISO 6336-2 apply. TECHNICAL REPORT ISO/TR 15144-1:2014(E) ISO 2014 All rights reserved 1PD ISO/TR 15144-1:2014ISO/TR 15144-1:2014(E) 3.2 Symbols and units The symbols used in ISO/TR 15144 are given in Table 1. The
36、 units of length metre, millimetre, and micrometre are chosen in accordance with common practice. The conversions of the units are already included in the given equations. Table 1 Symbols and units Symbol Description Unit a centre distance mm B M1 thermal contact coefficient of pinion N/(ms 0,5 K) B
37、 M2 thermal contact coefficient of wheel N/(ms 0,5 K) b face width mm C a1 tip relief of pinion m C a2 tip relief of wheel m C eff effective tip relief m c M1 specific heat per unit mass of pinion J/(kgK) c M2 specific heat per unit mass of wheel J/(kgK) c maximum tooth stiffness per unit face width
38、 (single stiffness) of a tooth pair N/(mmm) c mean value of mesh stiffness per unit face width N/(mmm) d a1 tip diameter of pinion mm d a2 tip diameter of wheel mm d b1 base diameter of pinion mm d b2 base diameter of wheel mm d w1 pitch diameter of pinion mm d w2 pitch diameter of wheel mm d Y1 Y-c
39、ircle diameter of pinion mm d Y2 Y-circle diameter of wheel mm E r reduced modulus of elasticity N/mm 2 E 1 modulus of elasticity of pinion N/mm 2 E 2 modulus of elasticity of wheel N/mm 2 F bt nominal transverse load in plane of action (base tangent plane) N F t (nominal) transverse tangential load
40、 at reference cylinder per mesh N G M material parameter g Y parameter on the path of contact (distance of point Y from point A) mm g length of path of contact mm H v load losses factor h Y local lubricant film thickness m K A application factor K H transverse load factor K H face load factor K v dy
41、namic factor n 1 rotation speed of pinion min 1 P transmitted power kW p et transverse base pitch on the path of contact mm2 ISO 2014 All rights reservedPD ISO/TR 15144-1:2014ISO/TR 15144-1:2014(E) Symbol Description Unit p dyn,Y local Hertzian contact stress including the load factors K N/mm 2 p H,
42、Y local nominal Hertzian contact stress N/mm 2 Ra effective arithmetic mean roughness value m Ra 1 arithmetic mean roughness value of pinion m Ra 2 arithmetic mean roughness value of wheel m S GF,Y local sliding parameter S safety factor against micropitting S ,min minimum required safety factor aga
43、inst micropitting T 1 nominal torque at the pinion Nm U Y local velocity parameter u gear ratio v g,Y local sliding velocity m/s VI viscosity improver v r1,Y local tangential velocity on pinion m/s v r2,Y local tangential velocity on wheel m/s v ,C sum of tangential velocities at pitch point m/s v ,
44、Y sum of tangential velocities at point Y m/s W W material factor W Y local load parameter X but,Y local buttressing factor X Ca tip relief factor X L lubricant factor X R roughness factor X S lubrication factor X Y local load sharing factor Z E elasticity factor (N/mm 2 ) 0,5 z 1 number of teeth of
45、 pinion z 2 number of teeth of wheel t transverse pressure angle wt pressure angle at the pitch cylinder B,Y pressure-viscosity coefficient at local contact temperature m 2 /N M pressure-viscosity coefficient at bulk temperature m 2 /N 38 pressure-viscosity coefficient at 38 C m 2 /N b base helix an
46、gle max maximum addendum contact ratio transverse contact ratio n virtual contact ratio, transverse contact ratio of a virtual spur gear overlap ratio total contact ratio 1 addendum contact ratio of the pinion 2 addendum contact ratio of the wheel Table 1 (continued) ISO 2014 All rights reserved 3PD
47、 ISO/TR 15144-1:2014ISO/TR 15144-1:2014(E) Symbol Description Unit B,Y dynamic viscosity at local contact temperature Ns/m 2 M dynamic viscosity at bulk temperature Ns/m 2 oil dynamic viscosity at oil inlet/sump temperature Ns/m 2 38 dynamic viscosity at 38 C Ns/m 2 B,Y local contact temperature C f
48、l,Y local flash temperature C M bulk temperature C oil oil inlet/sump temperature C GF,min minimum specific lubricant film thickness in the contact area GF,Y local specific lubricant film thickness GFP permissible specific lubricant film thickness GFT limiting specific lubricant film thickness of the test gears M1 specific heat conductivity of pinion W/(mK) M2 specific heat conductivity of wheel W/(mK) m mean coefficient of friction B,Y kinematic viscosity at local contact temperature mm 2 /s M kinematic viscosity at bulk temperature mm 2 /s 1 Poissons ratio of pinion 2 Poisso
