An efficient performance evaluation method of the traveling wave rotary ultrasonic motor’s flexible rotor

For a traveling wave rotary ultrasonic motor, matching the stator with a proper flexible rotor can be challenging because of the actual contact mechanism’s complexity. Due to the lack of effective evaluation and prediction means in the rotor design process, the prototype test is usually needed to truly measure how well it performs, leading to high cost and long design cycle. In order to solve this problem, an efficient performance evaluation method of the flexible rotor based on equivalent contact pressure is proposed. By the key parameters of the flexible rotor’s contact surface (area and pressure), an equivalent pressure model of the contact surface is established, which reveals the influence law of the flexible rotor’s structural parameters on the motor’s output performance. It is doubly verified by dynamics simulation and experiments. The advantage of this method is that without dynamics computation and prototype test, only statics analysis can evaluate the matching score of flexible rotor and target stator quickly and accurately. This study is expected to provide support for the structure design and performance prediction of the traveling wave rotary ultrasonic motor’s rotor, in which significant time and cost savings can be achieved.