Analysis of the 0.668″ traveling-wave piezoelectric motor

Piezoelectric ceramics are used in a wide variety of acoustic devices. A relatively recent use for the material is in piezoelectric motors. These motors supply a high torque with low rotor speeds in a small package. Essentially solid-state motors, they are fundamentally different in design than standard electromagnetic motors. An analytical composite model was created to help understand the functioning characteristics of the piezoelectric motor. Combining plate mechanics, simple vector analysis, and contact mechanics, the model accurately predicts the behavior of the motor and reveals the physics of its operation. In particular, the 0.668″ piezoelectric traveling-wave disk motor, developed by researchers in Japan, provides an excellent example to analyze. The motion of the internal components and the resultant output of the 0.668″ motor is determined and is shown to be close to experimentally measured values.