When larger models ball bearings or cylindrical roller bearings operate in pure radial load and low speed, due to the smaller centrifugal force of rolling body, so the rolling body in the load zone will impact the holder or raceway and then occure noisy. But with the increasing of the speed, the noise will disappear.

The method on control rolling body impact sound: reduce the radial clearance appropriately, use bearing that has reasonable structure and material having compliant cage.