TRIAL CONSTRUCTION OF A NONCONTACT ULTRASONIC MOTOR WITH AN ULTRASONICALLY LEVITATED ROTOR

We propose a new ultrasonic motor, in which the rotor is levitated and driven to rotate at very high speed by the ultrasonic field radiated from the stator into the air gap between the rotor and the stator. The noncontact bearing-less structure of this motor makes it possible to exceed the revolution speed limit of conventional contact ultrasonic m otors, and develop a new application of ultrasonic motors. Two motors with different resonance frequencies are fabricated, and their charact eristics are investigated experimentally.