ISO 10300-1:2014

INTERNATIONAL ISO
STANDARD 10300-1
Second edition
2014-04-01
Calculation of load capacity of bevel
gears —
Part 1:
Introduction and general influence
factors
Calcul de la capacité de charge des engrenages coniques —
Partie 1: Introduction et facteurs généraux d’influence
Reference number
©
ISO 2014
© 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 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
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2014 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and units . 2
5 Application . 8
5.1 Calculation methods . 8
5.2 Safety factors . 9
5.3 Rating factors . 9
5.4 Further factors to be considered .10
5.5 Further influence factors in the basic formulae .11
6 External force and application factor, K .12
A
6.1 Nominal tangential force, torque, power.12
6.2 Variable load conditions .12
6.3 Application factor, K .
A 13
7 Dynamic factor, K .13
v
7.1 General .13
7.2 Design .14
7.3 Manufacturing .14
7.4 Transmission error .14
7.5 Dynamic response .15
7.6 Resonance .15
7.7 Calculation methods for K .
v 15
8 Face load factors, K , K .25
Hβ Fβ
8.1 General documents.25
8.2 Method A .25
8.3 Method B .25
8.4 Method C .26
9 Transverse load factors, K , K .27
Hα Fα
9.1 General comments .27
9.2 Method A .28
9.3 Method B .28
9.4 Method C .30
9.5 Running-in allowance, y .
α 31
Annex A (normative) Calculation of virtual cylindrical gears — Method B1 .35
Annex B (normative) Calculation of virtual cylindrical gears — Method B2 .47
Annex C (informative) Values for application factor, K .53
A
Annex D (informative) Contact patterns .54
Bibliography .58
Foreword
ISO (the International 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 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 standardization.
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 accordance with the
editorial rules of the ISO/IEC Directives, Part 2. 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. Details 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. www.iso.org/patents
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 60, Gears, Subcommittee SC 2, Gear capacity
calculation.
This second edition cancels and replaces the first edition (ISO 10300-1:2001), which has been technically
revised.
ISO 10300 consists of the following parts, under the general title Calculation of load capacity of bevel
gears:
— Part 1: Introduction and general influence factors
— Part 2: Calculation of surface durability (pitting)
— Part 3: Calculation of tooth root strength
iv © ISO 2014 – All rights reserved

Introduction
When ISO 10300:2001 (all parts, withdrawn) became due for (its first) revision, the opportunity was
taken to include hypoid gears, since previously the series only allowed for calculating the load capacity
of bevel gears without offset axes. The former structure is retained, i.e. three parts of the ISO 10300
series, together with ISO 6336-5, and it is intended to establish general principles and procedures for
rating of bevel gears. Moreover, ISO 10300 (all parts) is designed to facilitate the application of future
knowledge and developments, as well as the exchange of information gained from experience.
Several calculation methods, i.e. A, B and C, are specified, which stand for decreasing accuracy and
reliability from A to C because of simplifications implemented in formulae and factors. The approximate
methods in ISO 10300 (all parts) are used for preliminary estimates of gear capacity where the final
details of the gear design are not yet known. More detailed methods are intended for the recalculation
of the load capacity limits when all important gear data are given.
ISO 10300 (all parts) does not provide an upgraded calculation procedure as a method A, although it
would be available, such as finite element or boundary element methods combined with sophisticated
tooth contact analyses. The majority of Working Group 13 decided that neither is it sufficient for an
International Standard to simply refer to such a complex computer program, nor does it make sense to
explain it step by step in an International Standard.
On the other hand, by means of such a computer program, a new calculation procedure for bevel and
hypoid gears on the level of method B was developed and checked. It is part of the ISO 10300 series as
submethod B1. Besides, if the hypoid offset, a, is zero, method B1 becomes identical to the set of proven
formulae of the former version of ISO 10300 (all parts):2001.
In view of the decision for ISO 10300 (all parts) to cover hypoid gears also, an annex, called: “Calculation
of virtual cylindrical gears — Method B2”, is included in this part of ISO 10300. Additionally, ISO 10300-2
is supplemented by a separate clause: “Gear flank rating formulae — Method B2”; regarding ISO 10300-3,
it was agreed that the former method B2, which uses the Lewis parabola to determine the critical section
in the root and not the 30° tangent at the tooth fillet as method B1 does, now be extended by the AGMA
methods for rating the strength of bevel gears and hypoid gears. It was necessary to present a new,
clearer structure of the three parts, which is illustrated in Figure 1 (of this part of ISO 10300). Note,
ISO 10300 (all parts) gives no preferences in terms of when to use method B1 and when method B2.
The procedures covered by ISO 10300 (all parts) are based on both testing and theoretical studies, but
it is possible that the results obtained from its rating calculations might not be in good agreement with
certain, previously accepted, gear calculation methods.
ISO 10300 (all parts) provides calculation procedures by which different gear designs can be compared.
It is neither meant to ensure the performance of assembled gear drive systems nor intended for use by
the average engineer. Rather, it is aimed at the
...