| 摘要 |
<p>PURPOSE:To improve durability by forming an energy accumulation device out of a soft elastic member and a relatively hard elastic member, and by first deflecting the soft elastic member and then the hard elastic member at the time of energy accumulation. CONSTITUTION:An energy accumulation device is placed on a rotation transmitting route between a reducing gear 15 for transmitting the rotation of a motor 13 to an input gear 21, and a pinion gear 17, and is formed also out of a spring 16 and a rubber 30. At the initial stage of accumulational operation, the spring 16 is deflected by a gap 15g by the rotational power transmitted from the side end of a protruded part 15c of the gear 15 to a load receiving part 16a of the spring 16. The spring is then compressed along a rubber 30 of a soft elastic member, and while the amount of deflection of the spring 16 is regulated in a certain range, the transmission of the impact force is prevented by the deflection power of the rubber 30. Durability can thus be improved, and breaking of the gear can be prevented.</p> |
