| 摘要 |
PROBLEM TO BE SOLVED: To improve drive efficiency by positioning an electric machine converting element for generating longitudinal vibration at a location including a longitudinal vibration node, and an electric machine converting element for generating torsional vibration at a location including a torsional vibration node so that they may be positioned roughly flush with each other. SOLUTION: A vibrator 11 is a member where a thick-wall hollow cylindrical body provided with four large-diameter parts 14A-14D and three small-diameter parts 14a-14c are slit into two pieces vertically. A two-layer piezoelectric element 12 for torsional vibration, a two-layer piezoelectric element 13 for longitudinal vibration and an electrode 15 are put between the split surfaces. The piezoelectric element 12 for torsional vibration 12 is disposed at a node of torsional vibration generated, and the piezoelectric element 13 for longitudinal vibration is disposed so as to cross a node of longitudinal vibration generated respectively. It is thus possible to reduce the number of parts used more than a conventional actuator and simplify assembly process. |
