| 摘要 |
PURPOSE:To prevent an unstable movement in an ultrasonic motor, by using a given material of a first frictional contacted face, and specifying a coefficient of friction between contacted faces of a stator and a rotor. CONSTITUTION:When a coefficient of friction between a stator 3 and a rotor 2 is 0.34, a hysteresis phenomenon occurs in a resonance characteristic curve, which represents a relation of a driving output of an ultrasonic motor 1 to a frequency of a driving power supply. In this case, the ultrasonic motor can not be driven stably. On condition that the coefficient of friction between the rotor 3 and stator 2 is below 0.25, the hysteresis phenomenon doesn't occur in the ultrasonic motor 1. When the coefficient is larger than 0.34, the hysteresis phenomenon is intensified. Consequently, the material of the stator 2 is so selected that the coefficient of friction between the rotor 3 and stator 2 becomes below 0.34 adequately. Then, the hysteresis phenomenon doesn't occur in the resonance characteristic operation, and the ultrasonic motor can be driven more stably. |
