| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress striking sound due to a gap in a peripheral direction between a rotor and a gear, and low frequency vibration which occurs at the time of low rotation of speed and low load torque. <P>SOLUTION: A plurality of groove parts 7a and 7b extending in a radial direction are arranged in the other end of the rotor 7 whose one end is brought into contact with a piezoelectric element. A plurality of engagement parts (83, 84 and 85) engaged with a plurality of the groove parts 7a and 7b are installed on an end face confronted with the rotor 7 in the gear 8. A plurality of beam parts 81A and 81B whose each end is brought into contact with an inner side wall corresponding to one of a plurality of groove parts 7a and 7b with prescribed force and which have spring property are disposed in a plurality of the engagement parts. <P>COPYRIGHT: (C)2008,JPO&INPIT |
