| 摘要 |
PROBLEM TO BE SOLVED: To secure a proper engagement between a rack tooth and a pinion so as to inhibit a gear engaging sound from being generated, by creating a support for a rack shaft at a gear housing position by using a rack bush provided with a characteristic surface in inner and outer peripheries thereof. SOLUTION: The rack shaft is supported in an inner peripheral portion of a tubular housing of a gear housing via a rack bush 8. An inner peripheral portion 8b of the rack bush 8 is formed as a peripheral surface approximately similar to a circle in which a peripheral surface 8f constituted by a large circular arc and a peripheral surface 8e constituted by a small circular arc are continuously provided. The rack shaft is not in contact with the peripheral surface 8f constituted by the large circular arc, and the peripheral surface 8e constituted by the small circular arc is formed as a support portion of the rack shaft. The support of the rack shaft by the peripheral surface 8e constituted by the small circular arc is not accomplished when a load applied to the rack shaft is nothing or low, but is accomplished when the load is high. Further, an engaging convex portion 8a acting as a positioning and rotation prevention for the bush 8 is provided in an outer peripheral portion 8b of the rack bush 8. COPYRIGHT: (C)2006,JPO&NCIPI |
