ROLLING BEARING FOR PROTECTING MAGNETIC BEARING

PROBLEM TO BE SOLVED: To provide a rolling bearing for protecting a magnetic bearing capable of preventing increase in an internal clearance of a protected bearing when a temperature recovers its normal state by preventing a raceway ring mounted on the rotary shaft side form easily reaching the yield stress even when the load of a rolling element is increased at a touch down. SOLUTION: In a rolling bearing for protecting a magnetic bearing, attached to the magnetic bearing capable of supporting a rotary shaft in a non-contact state, and receiving the rotary shaft 2 in the touch down, a double row angular contact ball bearing where a raceway ring 3 on the side to be mounted on the rotary shaft 2 side of the inner and outer rings is integrated, is used as a protective bearing on the side for loading the thrust load Fa or the side for axial positioning. Whereby the rigidity of the raceway ring 23 is increased, and the deformation amount and the internal stress are reduced. That is, the raceway ring hardly reaches the yield stress even when the load of the rolling element is increased, and increase in the internal clearance can be prevented when a temperature recovers its normal state.