| 摘要 |
PURPOSE:To increase the degree of freedom of a plurality of reduction gear ratio and smooth change-over operation by providing in each ring gear a non- engaging region without any engaging projection having a gap between engaging projections wider than the width of a lock pin. CONSTITUTION:Engaging projections 33, 34 are formed on the outer peripheral surfaces of ring gears 31, 32 at equal circumferential intervals. An engaging projection 33 is formed on one other axial end side of ring gear 31, an engaging projection 34 is formed on the other axial end side of ring gear 32 and a non- engaging region 35 is provided between both engaging projections 33, 34. Thus, a multiple state planet gear mechanism is selectively operate so that a plurality of different reduction gear ratios can be obtained. Also, in change-over between respective reduction gear ratios, the whole ring gears 31, 32 are set to the free condition on the way of change-over, so that the degree of freedom of reduction gear ratio setting can be increased and the change-over operation smoothed.
|
