| 摘要 |
PURPOSE:To maintain a high torque and a high rotation to be stable by providing a vibration receiving piezoelectric element at a part of a driving piezoelectric element, and bringing it into contact with a resonator. CONSTITUTION:A driving piezoelectric element 3 of an ultrasonic motor is brought into contact with a resonator 1, and a vibration receiving piezoelectric element 9 is provided at a part of the element 3. Further, a receiving positive electrode plate 10 of the same shape as that of the element 9 is provided at the part of a driving positive electrode plate 4 of the positive electrode side of the element 9, and insulating members 5 are respectively interposed between the elements 3 and 9 and between the plates 4 and 10. When the element 3 is vibrated, the element 9 detects a composite vibration of the vibration from the element 3 and a reflected wave from the resonator 1, and externally outputs from the plats 10. As a result, a driving frequency can be always set to an optimum frequency, and a rotor can stably be rotated. |
