| 摘要 |
PURPOSE:To provide a speed reduction gear which gives no shock to rotating operation of an input shaft by bringing a pair of planetary gears into pressure contact with opposite tooth surfaces of a sun gear and an internal gear, respectively when the input shaft is not driven. CONSTITUTION:A ring-shaped base 9a of a support arm 9 is rotatably fitted to an output shaft 7 between a support arm 6 integral with an output shaft 7 and an inner race of a bearing 23, and both bending portions 10a, 10b of a U- shaped bending spring 10 engaging with the outside of the circular base 9a are respectively engaged with neck portions of planetary gear shafts 11, 12 inserted through the forward portions of the support arms 6, 9, so that both support arms 6, 9 are urged to turn in the opposite direction to each other by substantially equal turning torque P. Accordingly, at least dring non-driving of an input shaft 1, a pair of planetary gears 5, 8 are respectively brought into pressure contact with opposite tooth surfaces of a sun gear 2 and an internal gear 4 not to give any shock to rotating operation of the input shaft. |
