ISO 3548-1:2022

INTERNATIONAL ISO
STANDARD 3548-1
Second edition
2022-08
Plain bearings — Thin-walled half
bearings with or without flange —
Part 1:
Tolerances, design features and
methods of test
Paliers lisses — Demi-coussinets minces à ou sans collerette —
Partie 1: Tolérances, caractéristiques de conception et méthodes
d'essai
Reference number
© ISO 2022
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Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 1
5 Dimensions and tolerances .4
5.1 Housing diameter, half bearing outside diameter and crush height . 4
5.2 Half bearing wall thickness and bearing bore . 4
5.3 Width of half bearing, distance between flanges, outside diameter of flange and
flange thickness . 6
5.4 Free spread . 7
6 Design features .10
6.1 General . 10
6.2 Locating nick and recess . 10
6.3 Reliefs and chamfers . 11
6.4 Transition between radial part and flange .12
6.5 Assembled flange scalloped toes. 14
6.6 Oil grooves and holes . 14
7 Test data for determining the peripheral length .17
7.1 Calculation of test force F. 17
7.2 Checking method A . 18
7.3 Checking method B . 19
8 Test data for determining axial width, B , of flange bearings .19
8.1 General . 19
8.2 Go between two parallel plates . 19
8.3 Axial width B checked under force . 20
9 Function and characteristics of assembled flange bearings .20
9.1 General . 20
9.2 Characteristics. 21
9.3 Classification . 22
9.4 Checklist of items for ensuring the function of assembled flange bearings.22
Bibliography .23
iii
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
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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 3,
Dimensions, tolerances and constructions details.
This second edition cancels and replaces the first edition (ISO 3548:2014), which has been technically
revised.
The main changes are as follows:
— normative references have been revised in Clause 2;
— symbols and terms with units have been added to Table 1;
— symbols in Figure 2 have been modified;
— symbols and measures in Figure 7 have been modified;
— Figures 3, 10 and 11 have been modified;
— symbols in 7.2 and 7.3 have been modified.
A list of all parts in the ISO 3548 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
INTERNATIONAL STANDARD ISO 3548-1:2022(E)
Plain bearings — Thin-walled half bearings with or
without flange —
Part 1:
Tolerances, design features and methods of test
1 Scope
This document specifies tolerances, design features and test methods for thin-walled half bearings with
integral flange up to an outside diameter of D = 250 mm and without flange up to an outside diameter
o
of D = 500 mm. Due to the variety of design, it is, however, not possible to standardize the dimensions
o
of the half bearings.
Half bearings according to this document are predominantly used in reciprocating machinery and
consist of a steel backing and one or more bearing metal layers on the inside.
In reciprocating machinery, flanged half bearings can be used in connection with half bearings without
flange.
Alternatively, to serve as a flanged half bearing, it is possible to use a half bearing without flange
together with two separate half thrust washers according to ISO 6526, or a half bearing with assembled
flanges.
NOTE All dimensions and tolerances are given in millimetres.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3548-3, Plain bearings — Thin-walled half bearings with or without flange — Part 3: Measurement of
peripheral length
ISO 6526, Plain bearings — Pressed bimetallic half thrust washers — Features and tolerances
ISO 21920-3, Geometrical product specifications (GPS) — Surface texture: Profile — Part 3: Specification
operators
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Symbols
Symbols and units are shown in Figures 1 and 2 and Table 1.
Key
1 joint face
2 sliding surface
3 bearing metal
4 bearing back
5 steel bearing backing
Figure 1 — Half bearing without flange with positive free spread
Figure 2 — Flange half bearing, integral or assembled, excluding free spread
Table 1 — Symbols and units
Symbol Description Unit
a Crush height mm
a Crush height in checking method A mm
A
a Crush height in checking method B mm
B
a Crush height on first joint face side in checking method B mm
B1
a Crush height on second joint face side in checking method B mm
B2
a Measuring point perpendicular to plane of joint face mm
a Circumferential length of locating nick mm
a Locating nick protrusion mm
a Locating recess depth mm
a Bearing bore relief length mm
a Sliding relief length mm
a Sliding relief length under 10° inclination mm
a Bending transition length mm
a Undercut length mm
a Groove centre distance mm
A Reduced area of cross section (calculated value) of half bearing mm
cal
A Face area of flange mm
f
b Distance to locating nick mm
b Locating nick width mm
b Distance recess centre to locating nick mm
b Distance locating nick groove to lubrication hole mm
b Locating recess width mm
b Clearance mm
b Oil groove width mm
G
b Housing width mm
H
B Half bearing width (without flange) mm
B Flange half bearing width mm
B Distance between flanges mm
c Inside chamfer mm
i
c Outside chamfer mm
o
d Diameter of the checking block bore mm
cb
d Housing diameter mm
H
D Outside diameter of flange mm
D Nominal inside diameter of the half bearing (bearing bore) mm
i
D Nominal outside diameter of the half bearing mm
o
D Outside diameter of the half bearing in the free state (with free spread) mm
o,E
e Amount of eccentricity mm
B
F Test force N
F Axial test force for assembled flange bearings N
ax
i Bearing bore relief height mm
i Flange bearing, sliding relief length mm
i Flange bearing, sliding relief length under 10° inclination mm
L Bottom limit of u —
Bu
L Upper limit of u —
Uu
Table 1 (continued)
Symbol Description Unit
P Amount of free spread mm
Ra Arithmetic average surface roughness µm
s Wall thickness (general) mm
s Steel backing thickness mm
s Bearing metal thickness mm
s Half bearing wall thickness mm
s Actual value of s —
3, act 3
s Wall thickness at the base of the groove mm
s Contact width assembled flange with hal
...