| 摘要 |
PROBLEM TO BE SOLVED: To provide a structure that can effectively prevent a ball bearing 16 for rotatably supporting an intermediate part of a pinion shaft 6 from being displaced in an axial direction, and is small-sized and can be configured at low costs.SOLUTION: In a part close to an opening on the inner peripheral surface of a sub-storage portion 12c composing a casing 10c, a locking groove 28b is formed over the whole periphery. On the locking groove 28b, a part close to the outer diameter of an approximately C-shaped retaining ring 29b is locked. This allows an axial direction side face of a part close to an inner diameter of the retaining ring 29b to be pressed against an axial side face of an outer ring 18 composing a ball bearing 16 that is internally-fitted and supported on the inner peripheral surface of the sub-storage portion 12c. To an opening edge of the sub-storage portion 12c, a clip 35 having an outer diameter side arm portion 43 and an inner diameter side arm portion 44 is attached, and a diameter reduction inhibition portion 36 composed of a tip portion of the inner diameter side arm portion 44 is inserted into a discontinuous portion 34 of the retaining ring 29b. |
