| 摘要 |
PURPOSE:To lower noises generated in case of operation by a mechanism wherein a bearing at the output shaft side of a motor is supported in a floatable shape, and planet gears are engaged with a shaft end of an output shaft. CONSTITUTION:The first-third concentric bearing holes 13a-13c are formed at the center of a cover body case 12 fixed to an end surface of a body case 11, and a motor shaft 14, to the outer circumference of nose thereof an external gear 14a is made up, is penetrated into the bearing holes 13a-13c. A fixed clearance alpha is formed between an inner circumferential surface 15a of a bearing metal 15 mounted to a second bearing hole and an outer circumferential surface of a base end of an external gear 14a of the motor shaft 14, and the motor shaft 14 is supported in a floating shape while an external gear 14a is engaged with the first three planet gears 23, which are supported by means of a first rotatory plate 22 and gear with a first fixed internal gear 19a. A first rotatory disc 22, a first planet gear and a sun gear 26 are floatably supported by means of the external gear 14a of the motor shaft 14, a first fixed internal gear 19a and a second planet gear in floating shapes. |
