超音波モータの原理と特徴

摘要

超音波モータは圧電素子で励振された超音波振動によrnってロータやスライダを擦って動かす摩擦駆動のモータrnである．従来の電磁型モータとは利用している物理現rn象が異なるので，その特性にも大きな差異がある．一般rnに，超音波モータは，電磁型に比べて低速·高トルクでrnあり，減速機構なしの直接駆動アクチュエータとして利rn用可能である．%Ultrasonic motor is a unique motor driven by piezoelectrically excited ultrasonic vibrations and friction force instead of electromagnetic force in conventional electric motors. Ultrasonic motors show high-torque and low-speed characteristics, quick responses, low emission of electromagnetic noise and self-braking function without energy consumption. This article reviews the operation principle, several types of configurations for both rotary and linear motions, and the performances as actuators. The concepts of traveling wave type and hybrid standing waves are presented in the first part, then the practical designs are explained. Motor characteristics are discussed in comparison with the conventional motors.