BUSH BEARING AND RACK-AND-PINION TYPE STEERING APPARATUS FOR AUTOMOBILE USING THE SAME

摘要

A bush bearing 7 includes a synthetic resin-made bush 17 having a circumferential groove 16 on an outer peripheral surface 15 thereof; an endless annular elastic member 18 fitted in the circumferential groove 16 of the bush 17; and a positioning means 19 for determining the position of the bush 17 in a B direction with respect to an inner peripheral surface 12 of a gear housing 6.

主权项

1. A bush bearing for allowing a rack shaft meshing with a pinion to be supported movably in an axial direction of the rack shaft, comprising: a synthetic resin-made bush having at least one circumferential groove in an outer peripheral surface thereof; and an endless annular elastic member which is fitted in the circumferential groove of said bush,
wherein said bush has an inner peripheral surface defining a through hole in which said rack shaft is inserted and fitted; at least one slit which partially severs the inner peripheral surface in a circumferential direction; a first contact portion which is formed on the inner peripheral surface so as to slidably come into contact with an outer peripheral surface of said rack shaft on a line extending in a direction perpendicular to the axial direction of said rack shaft and an axial direction of the pinion; and second and third contact portions which are formed on the inner peripheral surface in such a manner as to be respectively arranged with an interval with respect to the first contact portion in the circumferential direction with the first contact portion interposed therebetween in the circumferential direction and so as to slidably come into contact with the outer peripheral surface of said rack shaft, and wherein the inner peripheral surface at portions excluding the first to third contact portions is adapted to form a gap with respect to the outer peripheral surface of said rack shaft.