| 摘要 |
PROBLEM TO BE SOLVED: To provide a speed reducer using a sliding member for stably rotating first and second sun gears.SOLUTION: A rotary shaft 25 of a first-stage planetary gear reduction mechanism 24 is formed as a stepped shaft having a large-diameter shaft 27A and a small-diameter shaft 27B. Between a first sun gear 28 and a second sun gear 33, first and second half-split bushes 40, 41 are provided which are two half-split bodies having half-split cylinder parts 40A, 41A and flange parts 40B, 41B, respectively. In a through-hole 34 of the second sun gear 33, a small-diameter hole part 34B and a large-diameter hole part 34C are provided across a stepped part 34A. The half-split cylinder parts 40A, 41A of the respective half-split bushes 40, 41 are arranged in the small-diameter hole part 34B of the second sun gear 33, and the flange parts 40B, 41B are arranged in the large-diameter hole part 34C of the second sun gear 33. Thus, the first and second half-split bushes 40, 41 inhibited from being removed from the center of the rotary shaft 25 in the radial direction can be held in the small-diameter hole part 34B and the large-diameter hole part 34C, respectively.SELECTED DRAWING: Figure 4 |
