| 摘要 |
PURPOSE:To relieve a load on the inside part of the front of the bearing of a pinion gear by a method wherein a part on the front side of a planetary pinion gear is eliminated, and the shape in cross section in an axial direction of the pinion gear is formed longitudinally asymmetrically. CONSTITUTION:In a overdrive planetary gear unit 13, a part (a) on the front side of a planetary gear 17 is eliminated, and the shape in cross section in an axial direction of the gear 17 is formed longitudinally (laterally in a Fig) asymmetrically. Therefore, the weight of the gear 17 is decreased, and a centrifugal force exerted on the gear is reduced. Since the center of gravity of the gear 17 is moved to the rear side, a centrifugal force thereon is strongly exerted on a bearing 103 on the rear side. Thus, a load on an inner part 102a of a bearing 102 on the front side is relieved. Further, since a working point (b) of loads f4 and f5 exerted on the gear 17 of a ring gear 21 and a sun gear 19 is moved to be rear side, a load on an inside part 102a of the bearing 102 is further relieved. |
