Page 197 - needle bearings

Clearance-adjustable needle roller bearings
NTN

How to adjust radial clearance
The ratio of outer ring axial shrinkage to shrinkage of
roller inscribed circle diameter (Fw) is nearly 3:1. In other 2
words, the outer ring must be tightened by 3 mm in axial 1
direction to make the radial clearance smaller by 1 mm.
For adjustment of the radial clearance, the outer ring
must be tightened uniformly in parallel to the shaft center.
In the case of adjustment by the method illustrated in
Fig.1, a specific axial tightening value can be obtained by
changing the thickness of a spacer, which was inserted
between the housing and the lid, by lapping the spacer or
replacing it with another spacer. In the case of
adjustment by the method illustrated in Fig.2, the fixed
ring 2 is fitted in the housing and, thereafter, the threaded
lid 1 is screwed in until it comes in contact with the outer
ring for zero setting. Then, the threaded lid 1 is further
screwed in by the required value, after the fixed ring was Fig. 2
loosened, and thereafter the fixed ring 2 is retightened.
Further, it is recommended to use a saw-toothed
tightening screw as illustrated in Fig. 3 because
accuracy-down can be minimized by use of such a screw.

4ʙ7˚

Fig. 3

Fig. 1

B-135