Clearance reduction caused by interference fits

Performance and operating conditionsBearing type and arrangementBearing sizeLubricationOperating temperature and speedBearing interfacesBearing executionSealing, mounting and dismounting

An interference fit causes clearance reduction because inner rings are expanded and outer rings are compressed. The reduction equals the effective interference fit multiplied by a reduction factor using

Δrfit = Δ1 f1 + Δ2 f2

where
Δrfit clearance reduction caused by the fit [mm]
f1
reduction factor for the inner ring
f2 reduction factor for the outer ring
Δ1 effective interference between the inner ring and shaft [mm]
Δ2 effective interference between the outer ring and housing [mm]
Reduction factors valid for a solid steel shaft and a thick-walled cast iron or steel housing can be obtained from diagram 1 as a function of the ratio of the bearing bore diameter d to the outside diameter D. For the effective interference value, use the maximum probable interference value listed in the appropriate tables in Tolerances and resultant fits.
For a more detailed analysis, refer to SKF calculation tools, such as SKF Bearing Calculator, SKF SimPro Quick or SKF SimPro Expert, or contact the SKF application engineering service.
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