Abstract: A method and apparatus for mounting a bearing on a shaft. An intermediate member is mounted on the shaft. The inner race of the bearing is mounted onto the intermediate member. Two separable compression members are mounted on the outer diameter of the inner race. The compression members are mounted with an interference fit, thus inducing a state of compression in the inner race. The intermediate member is radially compliant and compensates for thermal growth of the shaft in excess of the thermal growth of the inner race. The state of compression in the inner race persists to about 1000° F. In one embodiment, the present invention includes an inner race fabricated from a material with low fracture toughness or for which a state of compression is desirable, such as a ceramic material.

Abstract: The present invention contemplates a combination bearing for supporting a rotating rotor within a gas turbine engine. The combination bearing including a magnetic bearing system and dry solid lubricated rolling element auxiliary bearings units for sharing the shaft load. The rotating central shaft being normally supported by the active electromagnetic bearing system. The auxiliary bearing unit being soft mounted to the shaft and engine housing and rotatable with the shaft. Soft mounting of the bearings between the housing and the shaft allows a substantially stable transition from the all magnetic bearing support to a physically contacting mechanically assisted support of the shaft.