An apparatus for attachment to the body ( 240 ) of a vehicle ( 12 ) which has a front, rear and opposite sides and which has steerable wheels. The apparatus comprises a lower part ( 22 ) having structure ( 40, 48 ) for fixed attachment at each of the opposite sides of the vehicle. A first steering control arm ( 150 ) is pivotally connected to the lower part ( 22 ) at one side of the vehicle. A second steering control arm ( 160 ) is pivotally connected to the lower part ( 22 ) at an opposite side of the vehicle. An upper part ( 24 ) is connected with the lower part ( 22 ). A rack and pinion steering mechanism ( 10 ) includes a rack bar ( 180 ) movable axially in opposite directions to effect steering movement of the steerable wheels of the vehicle. The steering mechanism ( 10 ) includes a chamber ( 80 ) through which the rack bar ( 180 ) extends. The chamber is defined by surfaces of the upper and lower parts ( 22, 24 ).

Rack housing for steering gear

In a rack guide disposed in a casing of a rack and pinion type steering system for slidably supporting a rack bar having rack teeth which engage with a pinion rotatably supported in the casing, the area for bearing the load of the rack bar can be fixed. A slide bearing member 21 has a three-layered structure consisting of a backing metal 22 made of bronze, a sintered alloy layer 23 and a synthetic resin layer 24 , the surface of the synthetic resin layer 24 comprising sliding-contact surface portions 25, 26 formed intermittently with the center thereof at the center of curvature “O” of a circular outer peripheral surface of a rack bar 16 and with a radius of curvature equal to the radius of curvature R 0 of the same, and the remaining surface portions 27 to 29 formed in other positions than the sliding-contact surface portions 25, 26 so as to be more dented than the sliding-contact surface portions 25, 26.

Rack guide in rack and pinion type steering system

An apparatus (10) for turning steerable wheels of a vehicle upon turning of a vehicle steering wheel comprises a housing (14) having a chamber (38), a rack (16) movable in opposite directions in the chamber to effect turning of the steerable wheels in opposite directions, a pinion (18) meshed with the rack, and a yoke (20) partially disposed in the housing and supporting the rack for sliding movement relative to the yoke. The yoke (20) comprises a molded plastic body having a recess (130) and a plate spring (150) located in the recess. The plate spring (150) has a surface (154) engaging the rack (16) and biasing the rack into engagement with the pinion (18). The plate spring (150) supports the rack (16) for sliding movement relative to the plate spring.

Apparatus for turning steerable vehicle wheels

A rack shaft is supported in an inner peripheral portion of a tubular housing of a gear housing via a rack bush. An inner peripheral portion of the rack bush is formed as a peripheral surface approximately similar to a circle in which a peripheral surface constituted by a large circular arc and a peripheral surface constituted by a small circular arc are continuously provided. The rack shaft is not in contact with the peripheral surface constituted by the large circular arc, and the peripheral surface 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 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 acting as a positioning and rotation prevention for the bush is provided in an outer peripheral portion of the rack bush.

Rack and pinion type power steering apparatus

A support yoke pressed against a rack bar to preload the rack relative to a pinion has a roller for guiding the rack bar by contact therewith. A plate of synthetic resin is interposed between each end face of the roller and the roller mount portion of the support yoke opposed thereto.

Rack and pinion steering device

A rack and pinion gear assembly 10 (FIG. 1) includes a resilient bushing which urges the rack into meshing engagement with the pinion. An arcuate inside bearing surface 54 (FIG. 4) of the bushing 18 has a larger radius of curvature than the curved outside surface 52 of the rack 12 against which it bears. The rack thus makes tangent contact with the bushing 18. When one portion of the bushing 18 is worn and therefore excessive play appears in the steering gear assembly 10, the bushing may be removed from the housing 16 of the assembly and rotated 180° and then reinserted into the housing to thereby provide an unworn bearing surface which slidably engages the rack 12. The bushing 18 includes a plurality of axially extending grooves 70, 72, 74, and 76 through which lubricant is supplied to the bearing surfaces 52 and 54. In a second embodiment (FIG. 5) the aperture 50b in the bushing 18b through which the rack 12b extends has a square cross section and is in tangent contact with the rack at two locations 84 and 86. In a third embodiment (FIG. 3) the aperture 50c in the bushing through which the rack 12c extends is composed of four arcuate segments 100, 102, 104, and 106 each having the same radius of curvature, and each having a different center of curvature 110, 112, 114, and 116, respectively. This provides tangent contact between the rack 12c and the bushing 18c at two axially extending areas 120 and 122.

John Whitney

Papers

Rack and pinion gear assembly