| 摘要 |
<p>PROBLEM TO BE SOLVED: To form a holding groove for holding lubricating oil in a part at which the inner wheel of a bearing is play-engaged with a steering shaft with a micro clearance and to rotate the steering shaft in relation to the inner wheel by means of the lubricating oil in the holding groove when rotation supporting function of the steering shaft by the bearing is lost due to rust or others. SOLUTION: The inner wheel 11A of a lower side bearing 11 is clearance- engaged with a bearing play-engaging portion 6D of a steering shaft 6, and the outer wheel 11B is press-engaged with a bearing press-in portion of a shaft mounting cylinder 2. A holding groove 8 linking with a tooth groove of a pinion 7 is formed in the bearing play-engaging portion 6D. Grease dropping from the pinion 7 and a rack 14 intrudes into this holding groove 8. When the lower side bearing 11 loses support function due to rust or others, the steering shaft 6 is rotated in relation to the inner wheel 11A.</p> |
