The torque free phenomenon of ultrasonic motors

Recently, the use of an ultrasonic motor (USM) has been improved as an in-the-car electric actuator with growth of the auto-industry. For example, it is Power window etc. It is because, the good drive in variable speed and which makes the small, lightweight, flat shape, and has a gear, brake, clutch’s functions are possible. However, there are three abnormal phenomena in this motor, and one of them is a torque free or out of phase phenomenon. In order to solve this phenomenon, in our Akiyama laboratory, it succeeded in the explication of the conventionally unknown torque free phenomenon, that by using of ATILA & GID software’s which the main subject will applied pzt-electric actuators was analyzed.