Rack guide of synthetic resin for a rack and pinion type steering device

A synthetic resin rack guide to be housed in a steering gear box for a rack and pinion type steering device, comprising:

• a generally semi-cylindrical head having a concave semi-cylindrical surface which has an axis, and positionable in a steering gear box for slidably pushing a semi-cylindrical back surface of a rack bar;
• an outer cylinder connected at a radially outer portion of said generally semi-cylindrical head and extending away from said generally semi-cylindrical head at a right angle with respect to said axis of said generally semi-cylindrical head to define a rack guide axis coincident with an axis of said outer cylinder, said outer cylinder including a plurality of slits which extend along said axis of the rack guide, said slits dividing said outer cylinder in a circumferential direction of the rack guide;
• an inner cylinder connected at a radially inner portion of said generally semi-cylindrical head and extending away from said generally semi-cylindrical head in parallel with said outer cylinder, said inner cylinder defining, in cooperation with said outer cylinder, a circumferential extending space between said cylinders which extends over an entire circumference of said rack guide;
• and
• a taper formed in an outer surface of said outer cylinder, said taper extending, in said axial direction of said rack guide, from a position which corresponds to a bottom of said concave semi-cylindrical surface to an edge of said outer cylinder connected to said generally semi-cylindrical head, said taper being so formed that a diameter of said rack guide becomes smaller in a direction toward said edge of said outer cylinder.

As synthetic resin rack guide to be housed in a steering gear box for a rack and pinion type steering device, comprising:

• a generally semi-cylindrical head having a concave semi-cylindrical surface which has an axis, and positionable in a steering box for slidably pushing a semi-cylindrical back surface of a rack bar;
• an outer cylinder connected at a radially outer portion of said generally semi-cylindrical head and extending away from said generally semi-cylindrical head at a right angle with respect to said axis of said generally semi-cylindrical head to define a rack guide axis coincident with an axis of said outer cylinder, said outer cylinder including a plurality of slits which extend along said axis of the rack guide, said slits dividing said outer cylinder in a circumferential direction of the rack guide;
• an inner cylinder connected at a radially inner portion of said generally semi-cylindrical head and extending away from said generally semi-cylindrical head in parallel with said outer cylinder, said inner cylinder defining, in cooperation with said outer cylinder, a circumferentially extending space between said cylinders which extends over an entire circumference of said rack guide;
• and
• a plurality of protrusions formed on both of said outer cylinder and inner cylinder and protruding into said circumferentially extending space, said protrusions formed on said outer cylinder overlapping with at least one portion of the protrusions formed on said inner cylinder in the circumferential direction of said rack guide.