| 摘要 |
A ring 50 that has an annular shape, and that includes an inner peripheral surfaces 50c that surrounds an outer peripheral surface of a pinion shaft 9 provided through a pinion 10, a gear-side end surface 50e that is provided on the side of the pinion 10, a bearing-side end surface 50b that is provided on the side of the bearing 4, and an outer peripheral surface 50d that is inclined from the gear-side end surface 50e toward an outer peripheral edge 50a of the bearing-side end surface 50b is provided between the pinion 10 and an inner race 6. When the length from the outer peripheral edge of the gear-side end surface 50e to an axial line 9c of the pinion shaft 9 is represented as L10, the length from a tooth root 11a of a large gear to the axial line 9c is represented as L11, the length from an outer peripheral edge 6j of a gear-side end surface 6b of a large-diameter-side flange portion 6g to the axial line 9c is represented as L2, and the length from the outer peripheral edge 50a of the bearing-side end surface 50b to the axial line 9c is represented as L3, the outer peripheral surface 50d has a shape satisfying the relationship expressed as L10<L11 and L3‰¥L2. |
