| 摘要 |
PROBLEM TO BE SOLVED: To facilitate the management of the tightening torque of a supersonic motor and obtain its desired rotational characteristic, by generating a longitudinal vibration in its stator, and by providing in its rotor a vibration converting means for converting the longitudinal vibration into a torsional vibration. SOLUTION: A supersonic motor includes a stator 1 which has first and second blocks 3, 4, first and second piezoelectric elements 5, 6, and first and second electrode plates 7, 8, and a rotor 2 with a plurality of slits 12 formed as a vibration converting means. The first electrode plate 7 of the stator 1 is connected electrically with the second block 4 via the first block 3 and through a bolt 9. Therefore, using the second electrode plate 8 as a common electrode plate, high-frequency AC voltages are applied to the first and the second piezoelectric elements 5, 6 in the upside-down polarity of the element 6. As a result, when the first piezoelectric element 5 expands and contracts, the second piezoelectric element 6 also contracts and expands. Then, transferring a longitudinal vibration generated in the stator 1 to the rotor 2, a torsional vibration is so generated in the rotor 2 by the slits 12 formed in it that the longitudinal and torsional vibrations give respectively a buoyancy and torque to the rotor 2. |
