Abstract
The characteristics and life of an ultrasonic motor are strongly related to the frictional material used on the sliding surface, because the motor is driven by frictional force and its life is limited to that of the frictional material. Hence wear evaluation of the frictional material is necessary for life prediction of the ultrasonic motor. In this experiment, the wear of carbon-fiber-reinforced plastics (CFRP) used as frictional material in ultrasonic motors is evaluated. The specific wear rate is derived from a simple wear test and is applied to estimate the wear of the CFRP used in the ultrasonic motor. The life of the ultrasonic motor, as well as that of frictional material, can be estimated using the equation derived from the experiment.