Systematic design and prototyping of a disc-typed traveling wave ultrasonic motor

A systematic way in the design of disc-typed traveling wave ultrasonic motor based on the fundamental operating mechanism of piezoelectric disc was proposed. Four disc-typed prototypes were designed and fabricated. A test rig was also constructed for the evaluation of the prototypes and basic characteristics of the actuators were investigated. The working principle of the traveling wave motor was verified during the experiment using laser vibrometer. Basically, the optimal angular velocity of the prototype is dependent on the driving frequency, the input voltage, the contact surface and the friction coefficient between the stator and rotor. An analytical study of the prototypes has been carried out by means of finite element analysis utilizing ANSYS®5.5. An equivalent circuit model is proposed for the estimation of the performance for the prototypes. Upon verification with the experimental results, we present a systematic method for the design of disc-typed ultrasonic motor according to the required specifications and application.