Abstract
A piezoelectric circular plate, which vibrates in non-axisymmetric or flexural vibration mode, is used for the stator vibrator of an ultrasonic motor. To design the stator vibra toradequately, the force factor of the vibrator should be estimated in advance. The theoretically calculated force factors for the two vibration modes are compared with the measured ones to obtain good agreement. In order to study how to control the force factor, the relation between the shape of the vibrator and the force factor is also con sidered.
