Page 125 - The Tribology Handbook

A22 Ro I I i n g bearing in st a llat i o n

SHAFT AND HOUSING DESIGN

R ig id i ty
1 Check the shaft slope at the bearing positions due to load deflection, unless aligning-type bearings are to be used.
2 Check that the housing gives adequate support to the bearing outer ring, and that housing distortion under load will
not cause distortion of the bearing outer ring.
3 Design the housing so that the resultant bearing slope is subtractive - see Figs. 22.l(a) and 22.l(b).

Fig. 22.1 (a). Incorrect - slopes adding Fig. 22.l(b). Correct - slopes subtracting

Alignment
1 For rigid-type bearings, calculate the shaft and housing slopes due to load deflection.
2 Determine the errors of housing misalignment due to tolerance build-up.
3 Ensure that the total misalignment does not exceed the values given in Table 22.1.

Table 22.1 Approximate maximum misalign-
ments for rigid bearings

Rigid bearing type Permitted misalignment
Radial ball bearings 1 .O mrad

Angular contact ball bearings 0.4 mrad
Radial roller bearings 0.4 mrad
Needle roller bearings 0.1 mrad

A22.1