ISO 12131-3:2020

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 12131-3
ISO/TC 123/SC 8
Plain bearings — Hydrodynamic plain
Secretariat: JISC
thrust pad bearings under steady-
Voting begins on:
2020-03-31 state conditions —
Voting terminates on:
Part 3:
2020-05-26
Guide values for the calculation of
thrust pad bearings
Paliers lisses — Butées hydrodynamiques à patins géométrie fixe
fonctionnant en régime stationnaire —
Partie 3: Paramètres opérationnels admissibles pour le calcul des
butées à segments
RECIPIENTS OF THIS DRAFT ARE INVITED TO
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DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 12131-3:2020(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
©
NATIONAL REGULATIONS. ISO 2020

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ISO/FDIS 12131-3:2020(E)

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ii © ISO 2020 – All rights reserved

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ISO/FDIS 12131-3:2020(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Guide values for avoiding damage caused by wear . 1
5 Guide values to avoid mechanical overloading . 2
6 Guide values to avoid thermal overloading . 3
Bibliography . 5
© ISO 2020 – All rights reserved iii

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ISO/FDIS 12131-3:2020(E)

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 (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. 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 (see www .iso .org/ patents).
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expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 123, Plain bearings, Subcommittee SC 8,
Calculation methods for plain bearings and their applications.
This second edition cancels and replaces the first edition (ISO 12131-3:2001), of which it constitutes a
minor revision. The changes compared to the previous edition are as follows:
— adjustments have been made to ISO/IEC Directives, Part 2:2018;
— typographical errors have been corrected.
A list of all parts in the ISO 12131 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved

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ISO/FDIS 12131-3:2020(E)

Introduction
In order to achieve that pad thrust, bearings calculated in accordance with ISO 12131-1 are sufficiently
reliable in operation, it is necessary that the calculated operational parameters h , T or T and p do
min B 2
not fall below or exceed the guide values h , T and p .
lim lim
lim
For limiting cases at high specific loads and/or high rotational frequencies, more accurate calculations
are necessary taking into consideration thermal, elastic, hydrodynamic and/or turbulence effects.
The guide values represent limiting values in the tribological system plain bearing unit which are
dependent on geometry and technology. These are empirical values which still give sufficient reliability
in operation even when subjected to slight disturbing influences (see ISO 12131-1:2020, Clause 5).
The empirical values given can be modified for specific fields of application.
© ISO 2020 – All rights reserved v

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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 12131-3:2020(E)
Plain bearings — Hydrodynamic plain thrust pad bearings
under steady-state conditions —
Part 3:
Guide values for the calculation of thrust pad bearings
1 Scope
This document specifies guide values for avoiding damage to thrust-pad bearings in service.
The explanation of the symbols as well as examples for calculation are given in ISO 12131-1.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databas
...