| 摘要 |
PROBLEM TO BE SOLVED: To provide a planetary reduction gear easily assembled in a short time and reduced in man-hours for assembling. SOLUTION: This planetary reduction gear has a sun gear 1 and an internal gear which are coaxial each other, and a plurality of planet gears laid between both gears 1, 2. Each cog 10 of the sun gear 1 has a taper portion 11 longitudinally tapering down at a tip end portion thereof. The taper portion 11 has a pair of an inclined surface 11b wherein the width of the cog tapering down in the circumferential direction from a cog surface 10b of the cog 10, and a taper surface 11a wherein an outer peripheral surface thereof tapering down in the radial direction from a cog tip surface 10a. In a process in which the sun gear 1 is inserted between the planet gears, even if the edge of the cog in each planet gear and the sun gear 1 are abuts against each other, the sun gear 1 is inserted in partway by the action of the taper surface 11a. If only slightly rotating, the sun gear 1 is guided by the inclined surface 11b and inserted, so that assembling can be facilitated. |
