Patent ID: 8002251

Claim:
A vibration reduction system for use in conjunction with a rotational device that includes a stationary body, a rotating body, and a first bearing assembly disposed between the stationary body and the rotating body, the vibration reduction system comprising: a first plurality of piezoelectric actuators residing between the stationary body and the first bearing assembly and configured to adjust the radial position of the first bearing assembly; a plurality of flexures positioned between the first plurality of piezoelectric actuators and the rotating body and deflecting in an axial direction in response to axial movement of the rotating body during operation of the rotational device to reduce shear forces transmitted to the first plurality of piezoelectric actuators, each of the plurality of flexures maintaining a different one of the first plurality of piezoelectric actuators under a predetermined compressive preload; a vibration sensor coupled to the stationary body; and a controller coupled to the vibration sensor and to the first plurality of piezoelectric actuators, the controller configured to reduce vibrations sensed by the vibration sensor by selectively adjusting the radial position of the first bearing assembly utilizing the first plurality of piezoelectric actuators.