ISO 21250-3:2020

Rolling bearings — Noise testing of rolling bearing greases — Part 3: Test and evaluation method MQ

This document specifies the testing and evaluation method of rolling bearing grease noise in accordance with the method MQ.

Roulements — Essais de bruit de graisse pour roulement — Partie 3: Méthode d’essai et interpretation MQ

General Information

• Status: Published
• Publication Date: 12-Jul-2020
• ICS: 21.100.20 - Rolling bearings
• Technical Committee: ISO/TC 4 - Rolling bearings
• Drafting Committee: ISO/TC 4 - Rolling bearings
• Current Stage: 6060 - International Standard published
• Start Date: 13-Jul-2020
• Due Date: 06-Feb-2021
• Completion Date: 13-Jul-2020

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 21250-3
First edition
2020-07
Rolling bearings — Noise testing of
rolling bearing greases —
Part 3:
Test and evaluation method MQ
Roulements — Essais de bruit de graisse pour roulement —
Partie 3: Méthode d’essai et interpretation MQ
Reference number
ISO 21250-3:2020(E)
©
ISO 2020

---------------------- Page: 1 ----------------------
ISO 21250-3:2020(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: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 21250-3:2020(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols, abbreviated terms and subscripts . 1
5 Calculation method . 2
6 Test method MQ . 2
6.1 General information . 2
6.2 Measuring principle . 3
6.3 Testing procedure . 3
6.3.1 Reference measurement of preserved, ungreased bearings . 3
6.3.2 Comparison measurement of greased bearings . 4
7 Evaluation of results . 4
7.1 General information . 4
7.2 Description of results . 4
7.2.1 Preserved bearings . 4
7.2.2 Greased bearings . 4
7.3 Grease noise classes — Rating scale . 5
7.4 Accuracy of results . 5
7.5 Permissible results in specifications . 6
7.6 Plausibility of results . 6
Annex A (informative) Test machine, test setup, electronic system and test reports: examples .7
Annex B (normative) Preparation of test bearings and greasing .13
Annex C (normative) Plausibility of the results .15
Annex D (informative) Example of grease noise classes rating .18
Bibliography .19
© ISO 2020 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 21250-3:2020(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).
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 4, Rolling bearings.
This document is intended to be used in conjunction with ISO 21250-1.
A list of all parts in the ISO 21250 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 ----------------------
ISO 21250-3:2020(E)

Introduction
The rolling bearing life theory emphasizes the use of pure and homogeneous lubricants as essential for
a long bearing service life. The lubrication of rolling bearings is described in several national standards.
[11]
The GfT worksheet 3 contains theoretical and practical knowledge of rolling bearing lubrication.
Grease lubrication is the most common type of rolling bearing lubrication. The purity grade of rolling
bearing grease is influenced by thickeners, base oils, additives and solid lubricant additives as well
as the manufacturing process and is reflected in the running noise. Therefore, noise testing of rolling
bearing greases is recommended.
In addition, grease noise testing after this document allows the grease manufacturers to develop low-
noise lubricants with highest damping properties. This document can also support the rolling bearing
manufacturers and end-users in the selection of low noise grease with better damping properties.
This document covers requirements for the testing assembly and the test machine of method MQ to
determine and assess the noise characteristics of rolling bearing grease jointly with ISO 21250-1,
ISO 21250-2 and ISO 21250-4.
© ISO 2020 – All rights reserved v

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 21250-3:2020(E)
Rolling bearings — Noise testing of rolling bearing
greases —
Part 3:
Test and evaluation method MQ
1 Scope
This document specifies the testing and evaluation method of rolling bearing grease noise in accordance
with the method MQ.
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 5593, Rolling bearings — Vocabulary
ISO 15242-1, Rolling bearings — Measuring methods for vibration — Part 1: Fundamentals
ISO 21250-1:2020, Rolling bearings — Noise testing of rolling bearing greases — Part 1: Basic principles,
testing assembly and test machine
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5593, ISO 15242-1, ISO 21250-1
and the following apply.
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/
3.1
sampling rate
sample rate
frequency with which a continuous signal is sampled and converted into a time-
discrete signal
Note 1 to entry: The unit is hertz (Hz) or samples (readings) per second [samples per second (samples/s)].
4 Symbols, abbreviated terms and subscripts
For the application of this document, the symbols, abbreviated terms and subscripts according to
ISO 21250-1:2020, Table 1 and Table 2, the symbols and abbreviated terms contained in Table 1 and
subscripts contained in Table 2 apply.
© ISO 2020 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO 21250-3:2020(E)

Table 1 — Symbols and abbreviated terms
Symbol Unit Description
GD — Grease damping
a
H — High band, H-band (1 800 Hz to 10 000 Hz)
i — Consecutive number
b
L — Low band, L-band (50 Hz to 300 Hz)
a
M — Medium band, M-band (300 Hz to 1 800 Hz)
−1
v µm∙s Vibration velocity
−1
µm∙s Vibration velocity, twice smoothed to the counting point i
v
i
a
Can be used as subscript, too, where necessary.
b
The L-band is used in noise and vibration analysis in the ISO 15242 series. However, this document does not consider
this frequency range for grease noise testing and its analysis.
Table 2 — Subscripts
Subscript-symbol Description
MP Measuring point
MQ Method MQ according to ISO 21250-3
a
NL Noise level, average value (of vibration velocity)
a
NP Noise peak
pk Peak value
ref Reference, ungreased bearing
rms Root mean square
0-32 Starting interval 0 s to 32 s
0-64 Interval 0 s to 64 s
32-64 Operating interval 32 s to 64 s
a
SUN Start-up noise of the greased bearing
a −1 −1
Noise values with this subscript can be expressed in µm∙s or in % based on the reference value of 16,9 µm∙s .
5 Calculation method
The formulae for calculation of grease damping and peak values are shown in ISO 21250-1:2020, Table 4
and Table 5, respectively.
A sampling rate of 8 readings per second shall be used, i.e. within 32 s, 256 points are required.
6 Test method MQ
6.1 General information
The procedure of MQ requires test bearings to be greased manually. The dosed/balanced quantities
of grease shall be introduced in to the bearings by means of a manual grease dosing unit (feeder) or a
spatula. There are five pre-greased bearings to be measured for a period of 64 s (each one with a run-in
time), as shown in Figure 1.
2 © ISO 2020 – All rights reserved

---------------------- Page: 7 ----------------------
ISO 21250-3:2020(E)

NOTE Five doses of grease × 64 s = 320 s (including run-in-time) measurement: 4 096 measuring points
(MP) at 32,768 kHz ≙ 0,125 s, thus 512 MP/grease dose and in total 2 560 MP.
Figure 1 — Duration of measurement— Process MQ
The process for the manual pre-greasing is represented in B.2.
6.2 Measuring principle
For the application of this document, the measuring principle, test bearings and amount of grease, test
load, spindle speed, signal recording and display of measuring results according to ISO 21250-1:2020,
Clause 7, applies. The peak detection algorithm for processing of the input signal is shown in
ISO 21250-1:2020, Table 5).
An example of a test machine, the test set-up, electronic system and test reports is given in Annex A.
6.3 Testing procedure
6.3.1 Reference measurement of preserved, ungreased bearings
The testing procedure shall include the following steps:
1) The noise tester shall be turned on and warmed up until a spindle temperature of 30 °C is reached
on the housing.
2) The MQ-test programme shall be started.
3) For five prepared (cleaned and newly preserved) test bearings (according to B.1), the reference
state shall be measured. The noise levels and noise peaks shall be in accordance with the allowed
values (see Table 3) for the test to proceed.
4) Mark an arrow on the outer ring side face of the test bearing with a permanent marker.
5) The test bearing shall be pushed on to the mandrel in such a way that the marking (arrow head) on
the outer ring points exactly to the sensor.
6) Apply the axial test load according to Table 3 on the test bearing.
7) Lower the sensor and start to rotate the spindle.
8) After this, start the measurement procedure.
9) After the measurement shut off the noise tester, loosen the loading device and withdraw the test
bearing from the mandrel.
10) Repeat steps 4) through 9) with the other four test bearings. The test bearings shall be sorted
according to order of testing (place 1 to 5).
11) Bearings that are worse than the allowed values (Table 3) shall be rejected. The measurement shall
then be repeated with an additional bearing, until five appropriate reference bearings are found.
© ISO 2020 – All rights reserved 3

---------------------- Page: 8 ----------------------
ISO 21250-3:2020(E)

Table 3 — Basic designation of the test bearings, axial loads, permissible noise level ν and
NL
permissible noise peaks ν
NP
Basic
Axial load
bearing Axial load Noise level Noise peak
tolerance
designation
−1 −1
N % µm · s µm · s
  ν ν ν ν
NL, M 0-64 NL, H 0-64 NP, M 0-64 NP, H 0-64
608 30 ±10 ≤8 ≤12 ≤2 ≤3
6202 60 ±10 ≤14 ≤16 ≤3,5 ≤4
6.3.2 Comparison measurement of greased bearings
Five appropriate test bearings shall be greased in the order of their reference measurements (in
accordance with B.2). Their measurement shall be carried out immediately afterwards in the same
sequence and as follows:
1) The test bearing shall be pushed on to the mandrel in such a way that the marking (arrow head) on
the outer ring points exactly to the sensor.
2) Apply the axial load according to Table 3 on the test bearing.
3) Lower the sensor and start to rotate the spindle.
4) After this, start the measurement procedure.
5) After the measurement shut off the noise tester, loosen the loading device and withdraw the test
bearing from the mandrel.
7 Evaluation of results
7.1 General information
For the use of measuring electronics equipment conforming to this document, the following applies:
1) The machine should have an automated test procedure.
2) The result shall be saved in a printable version and/or be printed on paper.
7.2 Description of results
7.2.1 Preserved bearings
For preserved bearings, the evaluation program indicates, in addition to the noise peaks from 0 s to
32 s, also the noise peaks from 32 s to 64 s and the noise level from 32 s to 64 s of all bearings in the M-
and H-bands as well as start-up noise and maximum values.
7.2.2 Greased bearings
For greased bearings, the grap
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 21250-3
ISO/TC 4
Rolling bearings — Noise testing of
Secretariat: SIS
rolling bearing greases —
Voting begins on:
2020-04-06
Part 3:
Voting terminates on:
Test and evaluation method MQ
2020-06-01
Roulements — Essais de bruit de graisse pour roulement —
Partie 3: Méthode d’essai et interpretation MQ
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 21250-3:2020(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

---------------------- Page: 1 ----------------------
ISO/FDIS 21250-3:2020(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: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/FDIS 21250-3:2020(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols, abbreviated terms and subscripts . 1
5 Calculation method . 2
6 Test method MQ . 2
6.1 General information . 2
6.2 Measuring principle . 3
6.3 Testing procedure . 3
6.3.1 Reference measurement of preserved, ungreased bearings . 3
6.3.2 Comparison measurement of greased bearings . 4
7 Evaluation of results . 4
7.1 General information . 4
7.2 Description of results . 4
7.2.1 Preserved bearings . 4
7.2.2 Greased bearings . 4
7.3 Grease noise classes — Rating scale . 5
7.4 Accuracy of results . 5
7.5 Permissible results in specifications . 6
7.6 Plausibility of results . 6
Annex A (informative) Test machine, test setup, electronic system and test reports: examples .7
Annex B (normative) Preparation of test bearings and greasing .13
Annex C (normative) Plausibility of the results .15
Annex D (informative) Example of grease noise classes rating .18
Bibliography .19
© ISO 2020 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO/FDIS 21250-3:2020(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).
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 4, Rolling bearings.
This document is intended to be used in conjunction with ISO 21250-1.
A list of all parts in the ISO 21250 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 ----------------------
ISO/FDIS 21250-3:2020(E)

Introduction
The rolling bearing life theory emphasizes the use of pure and homogeneous lubricants as essential for
a long bearing service life. The lubrication of rolling bearings is described in several national standards.
[12]
The GfT worksheet 3 contains theoretical and practical knowledge of rolling bearing lubrication.
Grease lubrication is the most common type of rolling bearing lubrication. The purity grade of rolling
bearing grease is influenced by thickeners, base oils, additives and solid lubricant additives as well
as the manufacturing process and is reflected in the running noise. Therefore, noise testing of rolling
bearing greases is recommended.
In addition, grease noise testing after this document allows the grease manufacturers to develop low-
noise lubricants with highest damping properties. This document can also support the rolling bearing
manufacturers and end-users in the selection of low noise grease with better damping properties.
This document covers requirements for the testing assembly and the test machine of method BQ+
to determine and assess the noise characteristics of rolling bearing grease jointly with ISO 21250-1,
ISO 21250-2 and ISO 21250-4.
© ISO 2020 – All rights reserved v

---------------------- Page: 5 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 21250-3:2020(E)
Rolling bearings — Noise testing of rolling bearing
greases —
Part 3:
Test and evaluation method MQ
1 Scope
This document specifies the testing and evaluation method of rolling bearing grease noise in accordance
with the method MQ.
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 5593, Rolling bearings — Vocabulary
ISO 15242-1, Rolling bearings — Measuring methods for vibration — Part 1: Fundamentals
ISO 21250-1:—, Rolling bearings — Noise testing of rolling bearing greases — Part 1: Basic principles,
testing assembly and test machine
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5593, ISO 15242-1, ISO 21250-1
and the following apply.
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/
3.1
sampling rate
sample rate
frequency with which a continuous signal is sampled and converted into a time-
discrete signal
Note 1 to entry: The unit is hertz (Hz) or readings per second [samples per second (samples/s)].
4 Symbols, abbreviated terms and subscripts
For the application of this document, the symbols, abbreviated terms and subscripts according to
ISO 21250-1:—, Table 1 and Table 2, the symbols and abbreviated terms contained in Table 1 and
subscripts contained in Table 2 apply.
© ISO 2020 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO/FDIS 21250-3:2020(E)

Table 1 — Symbols and abbreviated terms
Symbol Unit Description
GD — Grease damping
a
H — High band, H-band (1 800 Hz to 10 000 Hz)
a
i — Consecutive number
a
L — Low band, L-band (50 Hz to 300 Hz)
a
M — Medium band, M-band (300 Hz to 1 800 Hz)
−1
v µm∙s Vibration velocity
−1
µm∙s Vibration velocity, twice smoothed to the counting point i
v
i
a
The L-band is used in noise and vibration analysis in the ISO 15242 series. However, this document does not consider
this frequency range for grease noise testing and its analysis.
Table 2 — Subscripts
Subscript-symbol Description
MP Measuring point
MQ Method MQ according to ISO 21250-3
a
NL Noise level, average value (of vibration velocity)
a
NP Noise peak
pk Peak value
ref Reference, ungreased bearing
rms Root mean square
0-32 Starting interval 0 s to 32 s
0-64 Interval 0 s to 64 s
32-64 Operating interval 32 s to 64 s
a
SUN Start-up noise of the greased bearing
a −1 −1
Noise values with this subscript can be expressed in µm∙s or in % based on the reference value of 16,9 µm∙s .
5 Calculation method
The formulae for calculation of grease damping and peak values are shown in ISO 21250-1:—, Table 4
and Table 5, respectively.
A sampling rate of 8 readings per second shall be used, i.e. within 32 s, 256 points are required.
6 Test method MQ
6.1 General information
The procedure of MQ requires test bearings to be greased manually. The dosed/balanced quantities
of grease shall be introduced in to the bearings by means of a manual grease dosing unit (feeder) or a
spatula. There are five pre-greased bearings to be measured for a period of 64 s (each one with a run-in
time), as shown in Figure 1.
2 © ISO 2020 – All rights reserved

---------------------- Page: 7 ----------------------
ISO/FDIS 21250-3:2020(E)

NOTE Five doses of grease × 64 s = 320 s (including run-in-time) measurement: 4 096 measuring points
(MP) at 32,768 kHz ≙ 0,125 s, thus 512 MP/grease dose and in total 2 560 MP.
Figure 1 — Duration of measurement— Process MQ
The process for the manual pre-greasing is represented in B.2.
6.2 Measuring principle
For the application of this document, the measuring principle, test bearings and amount of grease, test
load, spindle speed, signal recording and display of measuring results according to ISO 21250-1:—
, Clause 7, applies. The peak detection algorithm for processing of the input signal is shown in
ISO 21250-1:—, Table 5 and Figure 1a).
An example of a test machine, the test set-up, electronic system and test reports is given in Annex A.
6.3 Testing procedure
6.3.1 Reference measurement of preserved, ungreased bearings
The testing procedure shall include the following steps:
1) The noise tester shall be turned on and warmed up until a spindle temperature of 30 °C is reached.
2) The MQ-test programme shall be started.
3) For five prepared (cleaned and newly preserved) test bearings (according to B.1), the reference
state shall be measured. The noise levels and noise peaks shall be in accordance with the allowed
values (see Table 3) for the test to proceed.
4) Mark an arrow on the outer ring side face of the test bearing with a permanent marker.
5) The test bearing shall be pushed on to the mandrel in such a way that the marking (arrow head) on
the outer ring points exactly to the sensor.
6) Apply the axial test load according to Table 3 on the test bearing.
7) Lower the sensor and start to rotate the spindle.
8) After this, start the measurement procedure.
9) After the measurement shut off the noise tester, loosen the loading device and withdraw the test
bearing from the mandrel.
10) Repeat steps 5) through 9) with the other four test bearings. The test bearings shall be sorted
according to order of testing (place 1 to 5).
11) Bearings that are worse than the allowed values (Table 3) shall be rejected. The measurement shall
then be repeated with an additional bearing, until five appropriate reference bearings are found.
© ISO 2020 – All rights reserved 3

---------------------- Page: 8 ----------------------
ISO/FDIS 21250-3:2020(E)

Table 3 — Basic designation of the test bearings, axial loads, permissible noise level ν and
NL
permissible noise peaks ν
NP
Basic
Axial load
bearing Axial load Noise level Noise peak
tolerance
designation
−1 −1
N % µm · s µm · s
  ν ν ν ν
NL, M 0-64 NL, H 0-64 NP, M 0-64 NP, H 0-64
608 30 ±10 ≤8 ≤12 ≤2 ≤3
6 202 60 ±10 ≤14 ≤16 ≤3,5 ≤4
6.3.2 Comparison measurement of greased bearings
Five appropriate test bearings shall be greased in the order of their reference measurements (in
accordance with B.2). Their measurement shall be carried out immediately afterwards in the same
sequence and as follows:
1) The test bearing shall be pushed on to the mandrel in such a way that the marking (arrow head) on
the outer ring points exactly to the sensor.
2) Apply the axial test load according to Table 3 on the test bearing.
3) Lower the sensor and start to rotate the spindle.
4) After this, start the measurement procedure.
5) After the measurement shut off the noise tester, loosen the loading device and withdraw the test
bearing from the mandrel.
7 Evaluation of results
7.1 General information
For the use of measuring electronics equipment conforming to this document, the following applies:
1) The machine should have an automated test procedure.
2) The result shall be saved in a printable version and/or be printed on paper.
7.2 Description of results
7.2.1 Preserved bearings
For preserved bearings, the evaluation program indicates, in addition t
...