Cryogenic temperature performance of traveling wave ultrasonic motor

Through testing investigation and theoretical analysis, the performance change of a traveling wave ultrasonic motor is studied at cryogenic temperature. An experimental system was built up, and the motor's characteristics were tested at cryogenic conditions. The influence of temperature on the friction interface was studied by comparing the material's surface appearances. This paper provides some guidance for the design and research on ultrasonic motor for operating in extraordinary conditions.