Design and experimental investigations of high power piezoelectric transducers for a novel squeeze film journal bearing

A novel active squeeze film journal air bearing actuated by high power piezoelectric transducers is presented. The proposed bearing uses in-air squeeze film levitation to suspend the rotating spindle without contact. Unlike conventional journal bearings, the presented bearing journal is formed by multiple independently vibrating surfaces driven individually by piezoelectric transducers. Langevin type piezoelectric transducers with a special radiation surface are developed. Detailed design procedures to develop the ultrasonic transducers are presented. A complete spindle-bearing system is constructed to test the proposed squeeze film bearing. Load carrying forces are measured at different vibration amplitude and compared with the calculated results. The proposed squeeze film journal bearing is operated in ultrasonic frequency range. The achieved load capacity is about 50N, which is five times of the load capacity achieved by the previous squeeze film bearings reported in the literatures.