SKF - Rolling Bearings

Design considerations
Abutment and fillet dimensions
The dimensions of components adjacent to a
bearing (such as shaft and housing shoulders,
spacer sleeves) must be able to provide sufficient
support for the bearing rings. However,
there must not be any contact between the rotating
parts of the bearing and a stationary
adjacent component. Appropriate abutment
and fillet dimensions are listed in the product
tables.
The transition between the bearing seat and
shaft or housing shoulder can be a fillet in accordance
with the dimensions r a and r b in the
product tables, or an undercut († table 13).
As the fillet radius increases, the stress distribution
in the fillet area improves. Therefore,
heavily loaded shafts, which typically require a
larger radius, use a spacing collar between the
inner ring and shaft shoulder to provide a sufficiently
large support surface for the bearing
ring. The side of the collar that abuts the shaft
shoulder should be designed so that it does not
contact the fillet († fig. 29).
Undercut dimensions
Bearing Undercut dimensions
chamfer
dimension
r s b a h a r c
mm mm
h a
b a
r s
r c
r s
b a
1 2 0,2 1,3
1,1 2,4 0,3 1,5
1,5 3,2 0,4 2
r s
r s
Table 13
h a r c
Fig. 29
2 4 0,5 2,5
2,1 4 0,5 2,5
3 4,7 0,5 3
4 5,9 0,5 4
5 7,4 0,6 5
6 8,6 0,6 6
7,5 10 0,6 7
9,5 12 0,6 9
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