Plain bearings — Hydrodynamic plain journal bearings under steady-state conditions — Part 4: Permissible operational parameters for calculation of multi-lobed and tilting pad journal bearings

This document establishes the permissible operational parameters in terms of guide values for the calculation of selected multi-lobed and tilting-pad journal bearings. In order to attain a sufficient operational safety of multi-lobed and tilting-pad journal bearings by the calculation according to ISO/TS 31657-1, it is necessary for the operational characteristic value hmin to be significantly above the permissible operating parameter hlim,tr and for the permissible operating parameters Tlim and plim not to be exceeded by the calculated operational characteristic values Tmax and pmax. The guide values represent geometrically and technologically founded operational limiting values in the tribological system of plain bearings. They are empirical values that enable sufficient operational safety even in the event of smaller disturbing influences (see ISO/TS 31657-1). The empirical values indicated can be modified for special application areas. NOTE The explanations for the symbols and calculation examples are contained in ISO/TS 31657-1.

titre manque — Partie 4: titre manque

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Published
Publication Date
09-Jun-2020
Current Stage
6060 - International Standard published
Start Date
24-Apr-2020
Completion Date
10-Jun-2020
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TECHNICAL ISO/TS
SPECIFICATION 31657-4
First edition
2020-06
Plain bearings — Hydrodynamic plain
journal bearings under steady-state
conditions —
Part 4:
Permissible operational parameters
for calculation of multi-lobed and
tilting pad journal bearings
Reference number
ISO/TS 31657-4:2020(E)
ISO 2020
---------------------- Page: 1 ----------------------
ISO/TS 31657-4:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

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: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/TS 31657-4:2020(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Operational guide values for start-up and run-down .................................................................................................... 1

5 Operational guide values for avoiding thermal and mechanical overloading .....................................4

6 Operational guide values for the bearing clearance ....................................................................................................... 5

Bibliography ................................................................................................................................................................................................................................ 6

© ISO 2020 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/TS 31657-4:2020(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).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

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.
A list of all parts in the ISO/TS 31657 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
---------------------- Page: 4 ----------------------
TECHNICAL SPECIFICATION ISO/TS 31657-4:2020(E)
Plain bearings — Hydrodynamic plain journal bearings
under steady-state conditions —
Part 4:
Permissible operational parameters for calculation of
multi-lobed and tilting pad journal bearings
1 Scope

This document establishes the permissible operational parameters in terms of guide values for the

calculation of selected multi-lobed and tilting-pad journal bearings.

In order to attain a sufficient operational safety of multi-lobed and tilting-pad journal bearings by the

calculation according to ISO/TS 31657-1, it is necessary for the operational characteristic value h

min

to be significantly above the permissible operating parameter h and for the permissible operating

lim,tr

parameters T and p not to be exceeded by the calculated operational characteristic values T

lim lim max
and p .
max

The guide values represent geometrically and technologically founded operational limiting values in

the tribological system of plain bearings.

They are empirical values that enable sufficient operational safety even in the event of smaller

disturbing influences (see ISO/TS 31657-1). The empirical values indicated can be modified for special

application areas.

NOTE The explanations for the symbols and calculation examples are contained in ISO/TS 31657-1.

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 databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Operational guide values for start-up and run-down

The minimum lubricant film thickness, h , is calculated for the operating point. Its size primarily

min

determines the requirements for the lubricant with respect to its cleanliness and defines the fineness of

the oil filter to be used.

At the transition of a hydrodynamic plain bearing into mixed friction, the minimum lubricant film

thickness, h , at the transition sliding speed, U , attains the value h .
min tr min,tr

In the range 0 < U < U the load percentage carried by solid body contact increases significantly with

decreasing rotational frequency.
© ISO 2020 – All rights reserved 1
---------------------- Page: 5 ----------------------
ISO/TS 31657-4:2020(E)

It depends on the energy density occurring in the contact area whether a permissible fine wear occurs

on the slidi
...

TECHNICAL ISO/TS
SPECIFICATION 31657-4
First edition
Plain bearings — Hydrodynamic plain
journal bearings under steady-state
conditions —
Part 4:
Permissible operational parameters
for calculation of multi-lobed and
tilting pad journal bearings
PROOF/ÉPREUVE
Reference number
ISO/TS 31657-4:2020(E)
ISO 2020
---------------------- Page: 1 ----------------------
ISO/TS 31657-4:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

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: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii PROOF/ÉPREUVE © ISO 2020 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/TS 31657-4:2020(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Operational guide values for start-up and run-down .................................................................................................... 1

5 Operational guide values for avoiding thermal and mechanical overloading .....................................4

6 Operational guide values for the bearing clearance ....................................................................................................... 5

Bibliography ................................................................................................................................................................................................................................ 6

© ISO 2020 – All rights reserved PROOF/ÉPREUVE iii
---------------------- Page: 3 ----------------------
ISO/TS 31657-4:2020(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).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

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.
A list of all parts in the ISO/TS 31657 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 PROOF/ÉPREUVE © ISO 2020 – All rights reserved
---------------------- Page: 4 ----------------------
TECHNICAL SPECIFICATION ISO/TS 31657-4:2020(E)
Plain bearings — Hydrodynamic plain journal bearings
under steady-state conditions —
Part 4:
Permissible operational parameters for calculation of
multi-lobed and tilting pad journal bearings
1 Scope

This document establishes the permissible operational parameters in terms of guide values for the

calculation of selected multi-lobed and tilting-pad journal bearings.

In order to attain a sufficient operational safety of multi-lobed and tilting-pad journal bearings by the

calculation according to ISO/TS 31657-1, it is necessary for the operational characteristic value h

min

to be significantly above the permissible operating parameter h and for the permissible operating

lim,tr

parameters T and p not to be exceeded by the calculated operational characteristic values T

lim lim max
and p .
max

The guide values represent geometrically and technologically founded operational limiting values in

the tribological system of plain bearings.

They are empirical values that enable sufficient operational safety even in the event of smaller

disturbing influences (see ISO/TS 31657-1). The empirical values indicated can be modified for special

application areas.

NOTE The explanations for the symbols and calculation examples are contained in ISO/TS 31657-1.

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 databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Operational guide values for start-up and run-down

The minimum lubricant film thickness, h , is calculated for the operating point. Its size primarily

min

determines the requirements for the lubricant with respect to its cleanliness and defines the fineness of

the oil filter to be used.

At the transition of a hydrodynamic plain bearing into mixed friction, the minimum lubricant film

thickness, h , at the transition sliding speed, U , attains the value h .
min tr min,tr

In the range 0 < U < U the load percentage carried by solid body contact increases significantly with

decreasing rotational frequency.
© ISO 2020 – All rights reserved PROOF/ÉPREUVE 1
---------------------- Page: 5 ----------------------
ISO/TS 31657-4:2020(E)

It depends on the energy density occurring in the contact area whether a permissible fine wear occurs

on the sliding surfaces
...

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