Improvement of driving efficiency of ultrasonic motor by improvement of vibration configuration

Abstract

An ultrasonic motor is generally composed of a vibrator and a rotor, and is driven by the frictional force between the vibrator/rotor. Since the contact points on the vibrator draw elliptic trajectory, relative speed of the point against the rotor varies even when the rotor rotates with a constant speed. This may cause abrasion between the vibrator/rotor and decrease in driving efficiency. This research proposes a novel method to reduce the relative speed to improve the driving efficiency of ultrasonic motors by superimposing harmonic vibrations with driving vibration. Results of numerical calculation show that driving efficiency may be improved by 27% by the proposed method.

Design of Optoelectronic Tracking Platform Driven by Ultrasonic Motor with a Novel Limiter

“…Therefore, it is necessary to adopt a new type of motor to improve the situation. As a prime mover, a rotating traveling wave ultrasonic motor (USM) offers low velocity, friction drive, self-locking, high-power density, high-position resolution, high positioning stiffness, and excellent electromagnetic compatibility [15,[21][22][23][24][25][26][27][28]. These unique characteristics have always attracted attention in the fields of aviation, medical care, robots, and precision driving [29][30][31][32][33].…”