| 摘要 |
PURPOSE:To perform fine control of rotary displacement or speed through variation of source voltage or frequency by providing a first longitudinal vibration element for contacting/separating a laminated torsional actuator with/from a fixed member through expansion/contraction and a second longitudinal vibration element which performs expanding/contracting vibration with reverse phase from that of the first longitudinal vibration element. CONSTITUTION:When alternating voltages having same frequency as that of a laminated torsional actuator A and phases matched to and shifted by 180 deg. from the actuator A are applied onto longitudinal vibration piezoelectric elements 8a, 8b, end boards 2a, 2b are clamped alternately to a cylindrical body 9. In stage I, upper end board 2 is clamped, and the lower end board 2 and an output shaft 10 rotate. In stage II, the lower end board 2 is clamped and only the upper end board 2 rotate. The output shaft 10 always rotates in a predetermined direction and the amount of rotation is proportional to the pulse being fed to the laminated torsional actuator A and the longitudinal vibration piezoelectric elements 8a, 8b. Consequently, function as a stepping motor can be achieved. |
