Patent ID: 6965181

Claim:
Bearing apparatus comprising a housing for receiving a rotor for relative rotational movement there between, a magnetic bearing assembly on said housing for magnetically interacting with the rotor for bearing the rotor, said magnetic bearing assembly including at least one first control coil for regulating magnetic interaction with the rotor on a first side axially of said housing, at least one second control coil for regulating magnetic interaction with the rotor on a second side axially of said housing, at least one first sensor for sensing radial position of the rotor on said first side of said housing, at least one second sensor for sensing radial position of the rotor on said second side of said housing, circuitry responsive to input of rotor radial position from said first sensor for outputting a signal to said first control coil for regulating amount of flux on said first side of said housing, circuitry responsive to input of rotor radial position from said second sensor for outputting a signal to said second control coil for regulating amount of flux on said second side of said housing, and circuitry utilizing data from said second sensor for regulating amount of flux on said first side of said housing if said first sensor is not operating properly.