Improving the Performance of Ultrasonic Motors in Low-Pressure, Variable-Temperature Environments

Abstract Ultrasonic motor (USM) performance is dependent on the tribological characteristics of the interface between a stator and rotor, which are sensitive to ambient environments and driving parameters. Thus, the effects of vacuum and temperature on the mechanical output performance and energy conversion efficiency of a traveling wave rotary ultrasonic motor 60 (TRUM-60) with a novel micro-dimpled PI-based friction material and optimized input parameters were systematically investigated for the first time. The degree of vacuum had a negligible effect on the performance of the TRUM-60, whereas temperature influenced its mechanical output torque, rotational speed, and output power. The results can aid in the design of USM devices for aerospace applications.