Working principle and design of a linear ultrasonic motor with rectangle-type stator

A linear ultrasonic motor with rectangle-type stator is proposed in this paper. The stator of proposed motor contains four longitudinal transducers, which are located in rectangle-type. Every transducer includes two exponential shape horns located on each end. And the horns of adjacent transducers intersect at tip ends where located a driving foot. Longitudinal vibrations are superimposed in the motor and generated elliptical trajectories at the driving feet. The working principle of proposed motor is analyzed. The resonant frequencies of two working modals are degenerated by adjusting the structure parameters. The motion trajectories of nodes on the driving feet are gained by transient analysis, results indicate that the motion trajectories of nodes on the four driving feet are ellipses. The vibration amplitudes of driving feet indicate the proposed motor has potential advantage in output characteristics. The results of this paper verify the theoretical feasibility and provide instructions for the development of proposed motor.