To get the best performance from a rolling contact bearing, the fit between the inner ring and shaft and outer ring and housing must be correct. If the mating surfaces lack interference, the inner ring may spin on the shaft or the outer ring may move in the housing. This unwanted movement is called ‘creep’. Once mating surfaces start to creep, the bearing ring will begin to wear excessively. Bearing creep can damage the shaft and/or the housing. Debris may enter the bearing causing over heating or vibration problems.
Creep is often impossible to prevent by just fastening of the bearing rings in an axial direction. To prevent or eliminate creep, the bearing ring that supports the rotating load must have an interference fit. The bearing ring that supports the stationary load normally does not require an interference fit. In some case where vibration is present, contact corrosion may require that both the inner and outer rings have interference fits.
To select the appropriate fit, the following items must be considered:
- Direction of load
- Characteristics of load
- Magnitude of load
- Temperature conditions
- Mounting and dismounting conditions
See accompanying table for general recommendations.