Design and Fabrication of Hexadecagon Type Ultrasonic Motor

Abstract

Ultrasonic rotary motor which has hexadecagon shape stator was proposed. Stator of the hexadecagon ultrasonic motor was composed of an elastic ring and ceramics. The elastic ring had sixteen sides and sixteen angular points. Eight ceramics were attached on the outer surface of the eight sides of the ring. When two sinusoidal voltages which have 90 degree phase difference were applied to each four ceramics, elliptical displacements of inner surface of the ring were obtained. These elliptical displacements of the inner surface rotated the shaft rotor through the frictions. The proposed hexadecagon ultrasonic motor was designed and analyzed by using the finite element method (FEM). Based on the FEM results, the rotational speed of the fabricated motor was measured by changing the driving frequency and voltage. As FEM results, large displacements at contact points of the stator could be obtained from thinner elastic ring and also thinner ceramics. Rotational speed of 61 [rpm] was obtained from the fabricated motor by applying 10 [V] of alternating voltages.