| 摘要 |
PURPOSE:To improve contacting state between an oscillator and a mover remarkably and to suppress noise in audible region by making a recess in an elastic body constituting the mover and forming a frictional member so that it covers at least the recess. CONSTITUTION:An annular recess 4 is made in an elastic body 1 on the side contacting with a protrusion on an oscillator and a mover 3 is constituted by applying a frictional member 2 onto the elastic body so that the frictional member 2 covers at least the recess 4. Unnecessary vibration due to fluctuation of amplitude between standing waves caused by areal shift or applying position shift from the oscillator having protrusion or theoretical radial inclination of oscillatory displacement are absorbed through surface correcting effect produced when the frictional member 2 on the recess 4 deforms along the distribution of oscillatory displacement. According to the constitution, allowance of flatness is enlarged and noise in audible region caused by beat components of driving frequency and unnecessary oscillation frequency due to restriction of machining or unnecessary oscillation can be eliminated. |
