GB/T 25769-2010 English PDF (GBT25769-2010)

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GB/T 25769-2010: Rolling bearings -- Measuring methods for radial internal clearance
GB/T 25769-2010
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 21.100.20
J 11
Rolling Bearings - Measuring Methods for
Radial Internal Clearance
ISSUED ON: DECEMBER 23, 2010
IMPLEMENTED ON: JUNE 1, 2011
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3 
1 Scope ... 4 
2 Normative References ... 4 
3 Measuring Principles of Radial Internal Clearance ... 4 
4 Preparation before Measurement ... 5 
5 General Specification for Measuring Apparatus ... 5 
6 Measurement of Radial Internal Clearance of Deep Groove Ball Bearing . 5 
7 Measurement of Radial Internal Clearance of Self-aligning Ball Bearing ... 9 
8 Measurement of Radial Internal Clearance of Cylindrical Roller and Needle
Roller Bearings ... 9 
9 Measurement of Radial Internal Clearance of Self-aligning Roller Bearing
... 10 
Rolling Bearings - Measuring Methods for
Radial Internal Clearance
1 Scope
This Standard specifies the measuring methods for the radial internal clearance of
deep groove ball bearing, self-aligning ball bearing, cylindrical roller bearing, needle
roller bearing and self-aligning roller bearing.
This Standard is applicable to the measurement of the radial internal clearance of
rolling bearing (hereinafter referred to as "bearing").
2 Normative References
The following normative documents contain the provisions which, through reference in
this text, constitute the provisions of this Standard. For dated references, the
subsequent amendments (excluding corrigendum) or revisions of these publications
do not apply. However, all parties who reach an agreement according to this Standard
are encouraged to study whether the latest edition is applicable. For undated
references, the latest edition applies.
GB/T 4199-2003 Rolling Bearings - Tolerances - Definitions (ISO 1132-1:2000,
MOD)
GB/T 4662-2003 Rolling Bearings - Static Load Ratings (ISO 76:1987, IDT)
JB/T 8788-1998 Feeler Gauge
JJF 1089-2002 Calibration Specification for Instruments for Measuring Radial
Clearance of Rolling Bearing
3 Measuring Principles of Radial Internal Clearance
3.1 The bearing radial internal clearance is measured by fixing one ring and
applying loads which are able to obtain stable measured value on the other unfixed
ring. Then do some reciprocating motion in the diameter direction.
3.2 Place the measuring head at the middle of unfixed ring and read the movement
value of the unfixed ring at every angular position (approximately uniformly distributed,
at least three) along the load direction; its arithmetic mean (subtracting the increment
of bearing radial internal clearance caused by measuring load) is the measured value
of bearing radial internal clearance.
4 Preparation before Measurement
Prior to measurement, the bearing shall be cleaned up. The grease and/or antirust
which are/is adherent to the bearing and may affect the measuring results shall be
removed and low viscosity oil lubrication shall be adopted. Certain structure of
pre-lubricated, sealing or shield bearing may affect the measuring accuracy. In order
to eliminate difference, for capped bearing, measurement shall be conducted before
closing.
Note: After measurement, bearing shall be protected against rust immediately.
5 General Specification for Measuring Apparatus
The design and application conditions of radial internal clearance measuring
apparatus shall meet the definitions related to the bearing radial internal clearance in
GB/T 4199-2003; the technical requirements and standards shall meet those
specified in JJF 1089-2002.
6 Measurement of Radial Internal Clearance of Deep
Groove Ball Bearing
When measuring this kind of bearing, the ball shall be dropped to the groove bottom.
6.1 Measuring with special measuring apparatus
6.1.1 Measuring without load apparatus (see Figure 1)
6.1.1.1 Prior to measuring, select suitable mandrel according to the dimension of
bearing; fix the inner ring of measured bearing on the end face of mandrel; adjust the
measuring load value (not greater than 5 N) and measuring head position to make
every part of apparatus be under normal condition.
6.1.1.2 During the measurement, make the measured bearing be under normal
measurement condition; rotate the inner ring for at least one complete circle and
alternately apply upper and lower measuring loads; the difference of average value of
the upper and lower positions read out from the apparatus is the measured value of
internal clearance.
different angular positions. The arithmetic mean of measured value for the several
times is the measured value of bearing radial internal clearance.
6.2.8 Because the radial internal clearance specified for bearing is the value under
the no-load state, in order to compensate the deformation that may be caused by the
effect of load in the measuring process, the measured value shall be corrected.
Note: If the pointer of indicator cannot clearly read out the maximum and minimum readings, the cause may be that
the washer is too thin.
6.2.9 When measuring large and heavy bearing, the flat washer shall be put
between the platform and the two rings of bearing.
6.3 Miscellaneous
The radial internal clearance of double row deep groove ball bearing shall be
measured in accordance with the methods specified in 6.1 and 6.2; the measuring
point shall be located at the middle of outer ring width.
7 Measurement of Radial Internal Clearance of
Self-aligning Ball Bearing
This kind of bearing shall be measured according to the methods specified in 6.1 and
6.2.
8 Measurement of Radial Internal Clearance of
Cylindrical Roller and Needle Roller Bearings
When measuring these two kinds of bearings, any one of the following three
measuring methods may be adopted; if there is a dispute, the measured value of
no-load internal clearance instrument shall prevail.
8.1 Measuring with special apparatus
The measurement shall be in accordance with the method specified in 6.1.
When measuring the needle roller bearing, the needle roller axis shall be parallel to
the raceway generatrix. When measuring the cylindrical roller bearing, the elastic
deformation caused by measuring load may not be considered.
8.2 Simple measuring method
The measurement shall be in accordance with the method specified in 6.2.