NTN - Precision Rolling Bearings

Technical Data
(6) Assembly and check of the mounted roller
outside diameter
¡Insert a spacer of widthR. Then insert the inner ring
and mounting spacer and tighten the shaft nut.
¡According to a procedure similar to that in steps (3)
Setting up the mounted internal clearance gage on
the main spindle and (4) Setup of inner ring
clearance, check the mounted roller outside diameter
and the clearance setting. Note this process is only a
re-check procedure, and may be omitted once the
clearance measurements fall in a smaller range.
Clearance correction factor and mounted
internal clearance reading
(1) Clearance correction factor
Because of the structure of the NTN mounted internal
clearance adjustment gage, the ratio of the clearance
reading on location for measurement to the reading on
dial indicator is 1:2.5 (clearance indication factor). The
clearance reading on the dial indicator is 2.5 times as
large as the remaining internal clearance. For
reference, a clearance reading conversion table is
given in Table 6.4.
NOTE: Note that the clearance correction factor of certain
bearing numbers is not 1:2.5. Correction factor is
given on the table of inspection results.
(2) Remaining internal clearance (where clearance
indication value 1:2.5)
The reading on the dial indicator is converted into a
mounted internal clearance in the
following manner:
¡CASE 1: The reading relative to the
zero point is in the clockwise
direction (CW) (Fig. 6.25). The
value of the mounted internal
clearance (+) is 1/2.5 times as large
as the reading on dial gage.
Reading on dial gage in Fig. 6.25 = 2.5
Remaining internal clearance = 2.5/2.5 = (+)1m
¡CASE 2: The reading relative to the zero point is in
the counterclockwise direction (CCW) (Fig. 6.26).
The value of the mounted internal clearance (-) is
Table 6.4 Clearance reading conversion table
Fig.6.25
1/2.5 times as large as the reading
on dial gage.
Reading on dial gage in Fig. 6.26
= 5.0
Remaining internal clearance =
5.0/2.5 = (-)2m
Setup of mounted internal clearance
When setting the mounted internal clearance to a
specific negative or positive value, the zero point on dial
indicator by a value [targeted clearance multiplied by
2.5] may be shifted prior to the setup of the clearance
adjustment gage. (In case that the mounted clearance
value is divided by the correction factor, it is not
necessary to the value [targeted clearance multiplied by
2.5])
(2.5: clearance correction factor)
Fig. 6.27 Adjustment for
negative clearance
(remaining internal
clearance: -0.8 m)
Fig. 6.28 Adjustment for
positive clearance
(remaining internal
clearance: +1.0 m)
Precautions for using and storing the mounted
internal clearance adjustment gage
When using the mounted internal clearance
adjustment gage, follow the precautions described
below:
¡When transferring the outer ring raceway diameter
measured with the cylinder gage to the mounted
internal clearance adjustment gage, use the
adjustment gage in a vertical attitude (Photo 6.8).
¡When not using the mounted internal clearance
adjustment gage, place it in a horizontal attitude
(Photo 6.9). Also, after completion of clearance
measuring operation, apply rust-preventive oil to the
internal clearance adjustment gage and store in a dry
location.
Fig.6.26
Reading on
dial gage
(m)
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Remaining internal
clearance on location
for measurement
(m)
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Reading on
dial gage
(m)
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
Remaining internal
clearance on location
for measurement
(m)
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
4.0
Photo 6.8 Vertical storage
attitude
Photo 6.9 Horizontal
storage attitude
36