| 摘要 |
PROBLEM TO BE SOLVED: To avoid or reduce the occurrence of a sticking phenomenon between a vibrating body and a contacting body, by reducing the press-contacting force between the vibrating and contacting bodies, or canceling the press-contacting state between the vibrating and contacting bodies while the vibrating and contacting bodies are in a prescribed positional relation. SOLUTION: Comb-teeth 52a are formed on the surface of an annular stator 52 and, when an electric signal is impressed upon a piezoelectric element attached to the rear surface of the stator 52, progressive waves are generated on the surface of the stator 52 and the amplitudes of the waves are expanded by means of the projections 52a. Since press-contacting coned disc springs 56 press-contact a mover 51 with the projections 52a by pressing the mover 51 when the amplitude of the progressive waves is expanded, the mover 51 rotates and generates torque. When an oscillatory wave driving device is maintained in the press- contacting state for a long period, a sticking phenomenon is generated by humidity fluctuation, principally. Therefore, projecting sections 51a-51c and a press-contact reducing spring 61, etc., are provided to the mover 51 and a casing 54 at three spots in the direction of rotation, and an elastic force is imparted to the mover 51 in the direction in which the mover 51 is separated from a casing 54 and the stator 52. Therefore, the occurrence of the sticking phenomenon can be avoided by nearly evenly reducing the press-contacting forces of the coned disc springs 56. |
