ULTRASONIC MOTOR AND METHOD FOR DRIVING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an ultrasonic motor which can move two components to be driven independently of each other.SOLUTION: A first group of frictional components brought into frictional contact with a first element positioned with a first angular distance is arranged on one end surface of an actuator 1 consisting of piezoelectric material. A second group of frictional components brought into frictional contact with a second driving element positioned with a second angular distance is arranged on the other end surface of the actuator 1. A reference electrode 17 is arranged on the inner peripheral surface of the actuator 1 and an exciting electrode 19 is arranged on the outer peripheral surface of the actuator 1. The exciting electrode 19 forms an oscillator of an ultrasonic standing wave with the reference electrode 17 and the piezoelectric material arranged between the exciting electrode 19 and the reference electrode 17. Voltage is applied to the oscillator in order to generate the ultrasonic standing wave. The first group of frictional components is arranged with a third angular distance with respect to the second group of frictional components, and the third angular distance is shorter than the first and second angular distances.