PIEZOELECTRIC MOTOR

PURPOSE:To miniaturize and lighten a piezoelectric motor by generating progressive vibrations in the side surface of an annular elastic body and turning a rotor pressure-welded to the elastic body. CONSTITUTION:Sine wave voltage generated by an oscillator 9 is applied to each annular forming piece 2A, 2B, 2C, 2D, respective piezoelectric element 1A, 1B, 1C. 1D, with phase difference of four kinds. Each piezoelectric element 1A-1D is displaced respectively by the applied voltage. Progressive vibrations are generated in the outer circumferential surface and side surface of an annular elastic body 2 by the displacement, and a rotor pressure-welded to the side surface is friction-driven and rotated. Accordingly, the piezoelectric elements 1A-1D are arranged to an annular section in the elastic body 2, thus miniaturizing and lightening a motor.