For radial bearings, the inner ring is usually a tight fit with the shaft, and run together with the shaft, and the bearing outer ring is usually mechanical or transition fit into the housing bore, play supporting role. However, in some cases, also the outer ring functioning, role play supporting fixed inner or the inner and outer rings are operated simultaneously.

For thrust bearings, tight fit with the shaft axis of said ring and move together with the bearing housing bore into mechanical or transition fit and play a supporting role in said seat. Rolling element (ball, roller or needle) held in the bearing means generally uniformly arranged between two carrier rings in rolling motion on its shape, size and number directly affects performance and load capacity of the bearing. In addition to the cage evenly spaced can start rolling the outside, but also from the guide rolling element bearing internal rotation and improve lubrication and so on.