摘要 |
In a rack and pinion power steering apparatus including a hydraulic cylinder housing, a pinion, a rack, a piston, a bolt for mounting the piston to the rack, etc., the rack is formed at one end thereof with a boss portion having a threaded portion which is formed with large inner diameter cylindrical cavity between the boss portion and the bolt in such a way that the female thread extends from a position radially corresponding to near the middle of the boss axial length or near the end surface of the rack to the bottom of the threaded portion. Therefore, it is possible to concentrate a load applied to the piston due to difference in pressure between two chambers to the relatively thick rack, not to the relatively thin boss portion, thus improving the mechanical strength of the steering apparatus without increasing the size or volume thereof. |