| 摘要 |
PURPOSE:To enhance the efficiency of an ultrasonic motor by employing a block having a diameter larger at the adhered side with a vibrator than at the contact side with a rotor as a stator. CONSTITUTION:When a voltage is applied to a vertical piezoelectric element 13 and a torsional piezoelectric element 14, phase difference of voltages is suitably regulated, and vertical resonance frequency is brought into coincidence with torsional resonance frequency at the time of high power excitation, the resonances are combined by vertical and torsional amplitudes in a boundary between a stator 18 and a rotor 19 to cause a strong elliptical vibrational. Since the protrusion of a lower part of a head mass 11 having a diameter large at the contact side with the element 13 than at the contact side with the rotor 19 does not have so high stiffness, it does not contribute to variation in the resonance frequency of the vertical vibration, but act as large inertial mass with respect to the torsional vibration. Accordingly, the resonance frequency of the torsional vibration is remarkably lowered. |
