ISO/TR 6281:1990

SLOVENSKI STANDARD
01-marec-2002
'UVQLOHåDML3UHVNXãDQMHOHåDMHYQDSUHVNXãHYDOLãþXSULKLGURGLQDPLþQHP
PD]DQMXLQPHãDQHPWUHQMX6PHUQLFH
Plain bearings -- Testing under conditions of hydrodynamic and mixed lubrication in test
rigs -- Guidelines
Paliers lisses -- Essai des paliers lisses dans les conditions de lubrification
hydrodynamique et mixte dans des machines d'essai pour paliers -- Principes directeurs
Ta slovenski standard je istoveten z: ISO/TR 6281:1990
ICS:
21.100.10 Drsni ležaji Plain bearings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL
ISO
REPORT
TR 6281
First edition
1990-04-15
Plain bearings - Testing under conditions of
hydrodynamic and mixed lubrication in test
rigs - Guidelines
Essai des paliers lisses dans /es conditions de lubrification
Paliers lisses -
hydrodynamique et mixte dans des machines d’essai pour paliers - Principes
directeurs
Reference number
ISO/TR 6281 : 1990 (E)
ISO/TR 6281: 1990 (El
Contents
Page
. . .
Ill
Foreword. .
iv
Introduction .
1 Scope .
................................................. 1
2 Normative references
......................................................
3 Testobjectives
...................................................
4 Test requirements.
5 Testprocedures .
6 Testcriteria. .
Annexes
..........................................
A Summary of the test criteria
B Testrigs .
......................... 10
C Conditions for obtaining comparable test results
D Bibliography .
0 ISO 1990
All rights reserved. No part of this publication may be reproduced or utilized in any form or by any
means, electronie or mechanical, including photocopying and microfilm, without Permission in
writing from the publisher.
International Organization for Standardization
Case postale 56 l CH-121 1 Geneve 20 l Switzerland
Printed in Switzerland
ii
ISO/TR 6281: 1990 (E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of
national Standards bodies (ISO member bedies). The work of preparing International
Standards is normally carried out through ISO technical committees. Esch 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, govern-
mental and non-governmental, in liaison with ISO, also take patt in the work. ISO
collaborates closely with the International Electrotechnical Commission (IEC) on all
matters of electrotechnical standardization.
The main task of ISO technical committees is to prepare International Standards. In
exceptional circumstances a technical committee may propose the publication of a
technical report of one of the following types :
when the necessary support within the technical committee cannot be
1,
- tYPe
obtained for the publication of an International Standard, despite repeated efforts;
is still under technical development requiring wider
- type 2, when the subject
exposure ;
-
type 3, when a technical committee has collected data of a different kind from
that which is normally published as an International Standard (“state of the art”, for
example).
Technical reports are accepted for publication directly by ISO Council. Technical
reports types 1 and 2 are subject to review within three years of publication, to decide
whether they tan be transformed into International Standards. Technical reports
type 3 do not necessarily have to be reviewed until the data they provide are
considered to be no longer valid or useful.
ISO/TR 6281, which is a technical report of type 2, was prepared by Technical
Committee ISO/TC 123, P/ain bearings.
the decision to publish this document in the form of a
The reasons which led to
technical report type 2 are explained in the introduction.
Annexes A, B, C and D of this Technical Report are given for information only.
. . .
Ill
ISO/TR6281:199O(E)
Introduction
Test rigs for plain bearings, using different test Systems, are used all over the world.
The wide range of practical applications with different requirements led to the design
of numerous test rigs for plain bearings. Unfortunately, since the conditions of lubri-
cation in these test rigs are usually not well defined, the test results obtained with one
rig cannot generally be directly compared with results obtained on another test rig, nor
tan the results be related to practical applications. Different test rigs may even produce
different rankings.
This Technical Report aims to improve the comparability and the transferability of the
results by a better definition of the operating conditions, in particular with regard to
I
conditions of lubrication.
The following Parameters tan be used to describe the lubrication adequately :
the minimum lubricant film thickness, its distribution as a fu
a) nction of time and
of location in the bearing under dynamic loading;
b) the maximum lubricant film pressure;
c) the distribution of pressure in the peripheral and the lateral directions as a func-
tion of time under dynamic loading conditions and the resulting (alternating)
Stresses in the bearing material;
the maximum and the mean lubricant film temperature, the coefficient of fric-
d)
as a function of
tion and the Variation of these Parameters time.
Since tribochemical reactions may occur between I u bricant and material, it is also
necessary to characterize the lubricant in as detailed a way as possible.
lt was therefore decided to first specify uniform guidelines for the testing of plain
bearings.
During the ISO/TR 123/SC 2 meeting in Vienna on 12 October 1984 it was decided to
make this method known in the form of a Technical Report. Further experience will be
gathered with a view to publishing an International Standard.
iv
ISO/TR 6281: 1990 (El
TECHNICAL REPORT
Testing under conditions
Plain bearings -
of hydrodynamic and mixed lubrication in test rigs -
Guidelines
1 Scope 3 Test objectives
The test objectives with plain bearing test rigs operating under
This Technical Report establishes guidelines for the testing of
conditions of mixed or full hydrodynamic lubrication may be to
oil-lubricated plain bearings without flange in bearing test rigs,
running under conditions of full hydrodynamic lubrication and obtain ‘information on the following properties :
mixed lubrication, where the load is carried to a greater or
running-in characteristics
A:
lesser extent by mechanical contact.
B : wear resistance
This Technical Report deals with both static and dynamic
loading in solid and multi-layer bearings. c: compatibility between bearing and shaft material
(resistance to scuffing)
Annex B gives examples of four types of test rigs.
D: embeddability
E: resistance to shaft scoring (which may result from con-
tamination with solid particles)
2 Normative references
F: static-load-carrying capacity
The following Standards contain provisions which, through
reference in this text, constitute provisions of this Technical G: deformability
Report. At the time of publication, the editions indicated were
H: conformability
valid. All Standards are subject to revision, and Parties to
agreements based on this Technical Report are encouraged to
dynamic-load-carrying capacity (fatigue strength)
1:
investigate the possibility of applying the most recent editions
J: resistance to erosion kavitation erosion, fluid erosion,
of the Standards listed below. Members of IEC and ISO main-
particle erosion)
tain registers of currently valid International Standards.
resistance to corrosion
K:
ISO 3448 : 1975, Industrial liquid lubricants - ISO viscosity
classifica tion. The determination of these properties requires operating con-
ditions which may result in the immediate establishment of full
hydrodynamic lubrication conditions or in mixed lubrication
ISO 3675 : 1976, Crude Petroleum and liquid Petroleum
conditions. The operating conditions needed for some objec-
products - Laboratory determination of density or relative
tives may imply repeated, time-dependent Change between full
density - Hydrometer method.
hydrodynamic and mixed lubrication.
ISO 7146 : - 11, Plain bearings - Terms, charac teris tics and
In any case, it is necessary to give a clear description of the
Causes of changes in appearance and darnage.
operating conditions and to relate them unambiguously to the
lubrication conditions (sec clause 6).
ISO 7902-1 : - 11, Hydrodynamit plain journal bearings under
Circular c ylindrical bearings -
s teady-s ta te conditions -
NOTE - Specific test methods exist for only some of the above
properties.
Part 7 : Calculation procedure.
, 1) To be published.
ISO/TR 6281: 1990 W
5.1.2.1 Parameters describing the surface topography of
4 Test requirements
sliding Partners, for example
The operating conditions tan be defined adequately only if the
test rig and the test procedure comply with the following re-
h
min
A -
(for test objectives A and B)
quirements :
= CR,
a) a simple mechanical construction;
b) simple dismantling procedures; it should preferably
possi ble to inspect the bearing in situ;
h is the minimum lubricant film thickness;
min
c) application of special measuring techniques: if poss-
is the sum of surface roughnesses of the sliding part-
CR,
ible, continuous wear measurements should be performed
ners.
by means of radio nuclide techniques or X-ray fluorescent
analysis of the lubricant; it should be possible to measure
lubricant film thickness, lubricant film and bearing
5.1.2.2 The particle size and the hardness of contaminating
temperatures and pressure distributions in the lubricant film particles (for test objectives D, E and, possibly, J).
and torque;
5.1.2.3 Parameters describing the surface topography and the
d) well defined dimensions of the test bearing : it should
hardness of both sliding Partners immediately before inten-
have a high dimensional stability and little shaft deflection.
tionally reducing the minimum lubricant film thickness (for test
In special cases it should be possible to vary the dimensional
stability or the shaft deflection; objective C).
adequate lubricant supply to be ensured without impair-
e)
5.1.2.4 Possible deviations in the geometry of the sliding part-
ing the oil pressure build-up;
ners (shaft deflection and local pressure marks in the plain bear-
f) hydrodynamic conditions should be well defined and
ing) (for test objectives G and 1).
experimentally verifiable;
5.1.2.5 The sliding velocity and the shear rate at minimum
a clear distinction should be made between
9)
clearance.
full hydrodynamic lubrication conditions;
the entire temperature and stress range that may occur
hl
5.1.2.6 The temperature of the lubricant film and of the bear-
in practice should be covered in the tests;
ing and, if necessary, the temperature distribution.
in case of dynamic loading, the bearing peripher-y
i)
be stressed as uniformly as possible.
5.2 Characteristic Parameters for test objectives
F, G, H and I
5 Test procedures
5.2.1 The maximum lubricant film pressure.
The actual test procedures depend on the properties to be
determined. In Order to ensure that test results obtained on
different test rigs are mutually compatible, and that results
5.2.2 The Variation in the lubricant film pressure in the
obtained on test rigs are applicable in practice, it is necessary to
peripheral and the lateral directions.
establish the Parameters describing the degree of hydro-
dynamic lubrication during the test. The test rig, the test
5.2.3 The Variation in the distribution of the lubricant film
Programme, the test conditions, the test bearing and, possibly,
pressure in the peripheral and the directions as a func-
other factors which may influence lubrication, should therefore
tion of time.
be described in detail. The characteristic Parameters which
should be known for each of the test objectives set, out in
clause 3 are given in 5.1 to 5.3.
5.2.4 The maximum static strain in the bearing material.
The characteristics which should be determined for each objec-
5.2.5 The maximum dynamic strain in the bearing material, in
tive are given in 5.4 to 5.7.
terms of mean and alternating strain, depending on the Point of
application, and as a function of 5.2.5.1 to 5.2.5.3.
5.1 Characteristic Parameters for test objectives
A, B, C, D and E
5.2.5.1 The construction of the bearing and the static
strength values of the individual layers of bearing material (for
5.1.1 The minimum lubricant film thickness determined by
test objectives F, G and H).
means of calculation of measurement.
5.1.2 5.2.5.2 The construction of the bearing and the dynamic
The Variation of the lubricant film thickness as a func-
tion of time, and the local development of small film strength values of the individual layers of bearing material in the
appropriate temperature ranges (for test objective 1; see also
thicknesses in the bearing as a function of the Parameters given
in 5.1.2.1 to 5.1.2.6. annex CL
ISO/TR 6281: 1990 (E)
The temperature of the lubricant film and of the bear- 5.7.2 Corrosive attack as a function of time.
5.2.5.3
ing and, if necessary, the temperature distribution.
5.7.3 Corrosion-free comparative tests, performed under the
same operating conditions (lubricant film thickness, shear rate,
5.3 Characteristic Parameters for test objective J
etc.) with a non-corrosive lubricant.
5.3.1 The Variation in the lubricant film thickness as a func-
tion of time and location in the bearing.
6 Test criteria
A distinction has to be made between the characteristic aspects
5.3.2 The distribution of Speed in the clearance gap,
of the test rig (6.11, the test Programme (6.21, the test con-
characterized for example by the maximum shear rate in the
ditions (6.31, the test bearing, including the journal (6.41, the
minimum clearance and its Variation as a function of time and
hydrodynamic Parameters (6.5) and the test results (6.6). The
of location in the bearing, related to the construction of the
characteristic aspects of the test rig, the test Programme, the
bearing and deviations in the geometry of the bearing as related
test conditions and the test bearing are of importante when
to the location and the degree of the wear darnage.
carrying out the test; the characteristic aspects of the
hydrodynamic Parameters and the test results are important
5.4 Characteristics for test objectives A, B, C, D when comparing and applying the results.
and E
Dur
...