JP2007290683A - Power steering device with adjustment mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for adjusting an engaged state between a rack and a pinion. <P>SOLUTION: A power steering device 30 is provided with a housing 32 extending along its longitudinal axis. A rack 34 is arranged within the housing 32 and supported by a bearing 40 in such a way that the rack 34 is moved along the longitudinal axis. A pinion 36 supported by the housing 32 is engaged with and fitted to the rack 34. The bearing 40 arranged around the rack 34 has a wall enclosing the rack 34 in a peripheral direction and having a radial thickness continuously changed. An adjustment mechanism supported by the housing 32 is connected to the bearing 40 so as to adjust the bearing 40 in such a way that it can be rotated in respect to the longitudinal axis. When the bearing 40 is rotated relatively by the adjusting mechanism in respect to the pinion 36, the radial thickness of the wall that is changed continuously determines a positioning of the rack 34 in such a way that an appropriate engagement and fitting between the rack 34 and the pinion can be positively attained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  This application claims the benefit of provisional application 60/695494 filed June 30, 2005.

  The present invention relates to a power steering apparatus for turning a steerable wheel of a vehicle having an adjustment mechanism for adjusting a rack and a pinion to an appropriate meshing engagement.

  Power steering devices with racks and pinions are used in almost all vehicles today to turn at least two of the vehicle's wheels. The control wheel of a vehicle is usually connected to a pinion gear that meshes and engages with a rack. The rack and the pinion are supported by the housing, and the rack converts the rotational movement of the pinion and the control wheel into a linear movement. This linear movement of the rack is transferred to the steerable wheels of the car by tie rods that are connected to each of the normally steerable wheels. In addition, the power steering system typically includes an auxiliary force device that supplies pressure or force proportional to the rotation of the control wheels to assist in linear movement of the rack. This auxiliary force is an additional system that can be a hydraulic system that uses a hydraulic piston connected to the rack or an electric system that uses an electric motor to supply auxiliary force to the rack. In either system, it is desirable to properly support the meshing engagement between the piston and the rack during the operational life of the power steering device and allow adjustment.

  The rack can be supported within the housing by bearings to reduce the frictional resistance of linear movement within the housing. This bearing also supports the rack and is usually adjustable to place the rack in proper meshing engagement with the pinion. This bearing, such as that disclosed in US Pat. No. 6,247,375, uses a yoke having a bearing surface that is eccentric to the housing in order to support the rack and adjust for proper mating engagement with the pinion. This yoke is installed in the housing of the power steering device. After installation, the yoke is rotated, thereby adjusting the support and positioning the rack in proper mating engagement with the pinion. The yoke is then permanently crimped in place by a tool that deforms the housing to support and secure the yoke in the rotated position. Since the yoke is crimped in place, the yoke and bearing support are not adjustable after the yoke is completely installed in the assembly. Thus, the yoke cannot adjust the rack after the vehicle has been assembled, and no further adjustments can be made during operation of the power steering assembly.

Other bearing designs, such as those disclosed in US Pat. No. 6,435,050, use a two-piece bearing design that includes a composite assembly to support the rack within the housing. This rack bearing is complex with a multi-piece bearing surface and requires additional bushings to support the rack for proper mating engagement with the pinion.
Patent Provisional Application No. 60/695494 US Pat. No. 6,247,375 US Pat. No. 6,435,050

  Accordingly, there is a need to provide a power steering device that includes a bearing having fewer components to support a rack that is in proper meshing engagement with the pinion. In addition, it may be desirable for some type of adjustment mechanism to engage the bearing to adjust the bearing to support the rack in proper meshing engagement with the pinion.

  The present invention provides a power steering apparatus that includes a housing extending along a longitudinal axis. The housing further includes a chamber having an inner surface. A rack is disposed within the chamber and is supported within the chamber for movement along the longitudinal axis. A pinion supported by the housing extends into the chamber to engage the rack. A bearing is disposed about the rack to engage the inner surface of the chamber and support the rack within the housing. The bearing includes a continuously varying radial thickness wall that circumferentially surrounds the rack. An adjustment mechanism is supported by the housing and is coupled to a bearing that adjusts the bearing for rotation relative to the longitudinal axis. The continuously changing radial thickness of the wall thereby positions the rack with respect to the pinion and ensures proper intermeshing engagement between the rack and the pinion.

  The present invention includes a bearing and an adjustment mechanism that engages the bearing while reducing assembly complexity. This adjustment mechanism is of a clever design that can be adjusted from the beginning to the end of the operating life of the power steering device.

  Other advantages of the present invention will be readily appreciated and simultaneously better understood by reference to the following detailed description when considered with reference to the accompanying drawings.

  Referring to the figures in which like reference numerals indicate corresponding parts throughout the several views, the power steering apparatus is shown generally at 30 in FIGS. As best shown in FIGS. 1 and 2, the power steering apparatus 30 includes a housing 32 that extends along a longitudinal axis 42. The housing 32 has a chamber 44 that extends along the longitudinal axis 42 and that defines an inner surface 46, best shown in FIG. The housing 32 includes an opening 48 that extends into the chamber 44 for receiving an adjustment mechanism 38 (discussed in more detail below). The housing 32 further includes an adjacent extension 50 coupled to the chamber 44 (also discussed in more detail below) and extending to rotatably support the pinion 36. This adjacent extension 50 is generally transverse to the longitudinal axis 42 and the chamber 44. Inner surface 46 of housing 32 also includes a groove 52 that extends annularly about longitudinal axis 42 to position bearing 40, as will be discussed fully below. Referring to FIG. 3, the housing 32 may optionally include a bearing 54 and other markings 54 or other mechanisms to assist in assembly into the housing 32, this use in conjunction with the bearing 36 will be described below. To discuss further.

  As best shown in FIG. 4, the inner surface 46 defines two diameters 56, 58. The first diameter 56 is centered on the longitudinal axis 42 and the second diameter 58 is centered on the second axis 60. The inner surface of the housing further includes a shoulder 62 between the first diameter 56 and the second diameter 58. The shoulder 62 further includes chamfers and retractions to create a more gradual transition between the first diameter 56 and the shoulder 62. The first diameter 56 can be offset by an amount that will vary depending on the inner surface 46 and the design of the bearing 40 to be supported within the inner surface 46. However, as is known in the art, the inner surface 46 of the housing 32 can have different diameters and configurations with offset distances that vary between the longitudinal axis 42 and the second axis 60. It will also be appreciated that there may be no offset that will vary depending on the design of the bearing 40, the configuration of the rack 34, and the space and dimensional constraints to the power steering device 30 within a given application. Those skilled in the art will also appreciate that the inner surface 46 of the housing 32 can be configured in various shapes to support and position the bearings 40 and the rack 34 within the housing, as discussed further below. .

  Referring to FIGS. 5 and 6, the rack 34 is disposed within the chamber 44 of the housing 32 and linearly along the longitudinal axis 42 in response to the rotational movement of the pinion 36 as is known in the art. Moving. The pinion 36 is rotatably supported by the adjacent extension 50 of the housing. As is known in the art, the adjacent extension 50 typically includes a rotational support for supporting the piston 36, i.e. a region for press-fitting a rolling bearing. The rack 34 defines a plurality of teeth 64 for mating with the pinion 36, as is well known in the art. The rack 34 converts the rotational movement of the pinion 36 into a linear movement. In a typical application such as a passenger car, the pinion 36 is connected to a control wheel (not shown) and rotates in relation to the movement of the control wheel by the operator. A rack 34, which is coupled to and moved by the steerable wheels of the vehicle, typically via a tie rod that engages each of the steerable wheels, converts the rotational movement of the pinion 36 into linear movement. As is known in the art, the power steering device 30 typically includes an auxiliary force (not shown) for moving the rack 34 within the housing 32. This auxiliary force is generally created by a mechanical system such as hydraulic, electrical or various other auxiliary techniques as known in the art.

  With reference to FIGS. 5, 6, 7, 8 and 9, the rack 34 is supported within the housing 32 by bearings 40. The bearing 40 of the present invention includes a wall 66 having a continuously varying radial thickness that circumferentially surrounds the rack 34 within the housing 32. This wall of the bearing 40 has an outer surface 68 and an inner surface 70. The bearing 40 further includes a damping mechanism 100 for damping the play movement of the rack 34 against the inner surface 46 of the housing 32 within the bearing 40. The outer surface 68 is provided for engaging a damping mechanism 100 that can have many electrical measurement materials and instrument configurations as will be appreciated by those skilled in the art. The damping mechanism 100 can be further defined as an O-ring that engages the outer surface 68 of the bearing 40. This O-ring is a polymeric material having elastic properties, thereby providing a dampening of play movement of the rack 34 relative to the pinion 36 and the housing 32. As shown in FIG. 5, the O-ring engages in a groove in the outer surface 68 and is disposed between the outer surface 68 of the bearing 40 and the inner surface 46 of the housing 32.

  Referring to FIG. 6, the wall 66 of the bearing 40 can optionally define a scallop 114 extending inwardly along the longitudinal axis 42. The scallop 114 defines a notch from the wall 66 of the bearing 40 so that the bearing 40 can be designed and positioned within the chamber 44 relatively close to the pinion 36 as shown in FIG. A bearing 40 located near the pinion 36 allows the bearing 40 to support the rack 34 against bending and torsional forces caused by intermeshing engagement with the pinion 36. FIG. 6 shows the wall 66 of the bearing 40 having a scallop 114 that removes a portion of the wall 66 so that the pinion 36 can engage and mesh with the rack 34. Thus, this scallop 114 allows a portion of the wall 66 of the bearing 40 to extend along the rack 34 on the opposite side of the pinion 36 to support the rack 34 in meshing engagement with the pinion 36. The position of the bearing 40 is important to support the counter force generated by the intermeshing engagement between the pinion 36 and the rack 34. The closer the bearing 40 is to the meshing position of the pinion 36 with respect to the rack 34, the less the lever force between the meshing engagement of the rack 34 and pinion 36 and the bearing 40. The reduced lever force thereby improves the support of the rack 36 and prevents the rack 36 from flexing and disengaging from proper engagement with the pinion 38. Further, the position of the bearing 40 near or below the pinion 36 reduces the risk of noise or vibration as a result of idle movement of the rack 34 due to high loads on the device 30.

  The bearing 40 further includes a mechanism to help position and orient the bearing 40 within the chamber 44 of the housing 32 during assembly of the device 30. As shown in FIG. 7, the bearing 40 includes an orientation extension 104, which in this embodiment is a cylinder, for positioning the bearing 40 relative to the housing 32. For example, the orientation extension 104 can be used to find the top or 12 o'clock position of the bearing 40 or optionally align with the marking 54 on the housing 32. The marking 54, discussed above, is as shown in FIG. The bearing 40 is preferably oriented relative to the housing 32 in the chamber 44 such that a 10 to 12 degree rotation from the nominal position increases the clearance and causes the rack 34 to be positioned below the longitudinal axis 42. . By initially supporting the rack 32 below its nominal position during assembly, additional clearance is created between the rack 34 and the pinion 36. This clearance is necessary so that the pinion 36 can be incorporated into the device 30 in meshing engagement with the rack 34. However, those skilled in the art will appreciate that there are numerous ways to determine the orientation of the bearing 40 using additional assembly tools. This additional clearance is removed by an adjustment mechanism 38 that rotates the bearing 40 to place the rack 34 in proper mating engagement with the pinion 36, which will be fully discussed below.

  The groove 52 in the inner surface 46 of the housing 32 provides a positive and reference position for the bearing 40 within the chamber 44 of the housing 32. The wall 66 of the bearing 40 includes a leading end 106 and a trailing end 108 that define a bearing width. The rear end 108 of the bearing 40 includes fingers 110 that are biased outwardly from the bearing 40 for engagement within the groove 52, providing a secure position of the bearing 40 within the chamber 44. The finger 110 removably secures the bearing 40 that engages the groove 52 of the chamber 44 and allows removal of the bearing 40 if necessary without damaging the housing 32 and / or the bearing 40. Optionally, the rear end 108 may include a series of alternating fingers 110 and notches 112 around the circumference of the bearing 40 for engaging the groove 52 and positioning the bearing 40 as shown in FIG. This removable aspect of the bearing 40 is an expensive component to the product, and damage to the inner surface 46 can lead to additional machining costs for scrap parts or refinishing of the inner surface 46 of the housing 32. Advantageously, the bearing 40 can be removed from the housing 32 without damaging the inner surface 46 of some housing 32.

  Further, the rear end 108 of the bearing 40 may further include a stop that engages the rack 34. This stop may simply include an inner surface 70 having a chamfer at a diameter smaller than the end diameter of the rack 34. There are a number of ways for the bearing 40 to prevent the rack 34 from passing completely through the bearing 40, and thus one is to create a stop in the housing 32 for linear movement of the rack 34. Using the bearing 40 as a stop limits the movement of the rack 34 within the housing 32 when the dimensions of the housing 32 are critical and additional components or additional complexity relative to the inner surface 46. It is particularly advantageous to eliminate the need to design in the mechanism for

  The wall 66 of the bearing 40 further includes a mechanism that improves the manufacturability of the bearing 40. The wall 66 may define a cavity 116 or a series of cavities 116 that extend from the tip 106 of the bearing 40 along the longitudinal axis 42 toward the rear end 108. This cavity 116 allows for a uniform curing of the polymer material of the bearing 40 during manufacture of the bearing 40. FIG. 8 shows a wall 66 having a series of cavities 116. This cavity 116 increases the likelihood that the polymeric material of the bearing 40 will cure uniformly with little or no unevenness on the inner surface 46 of the bearing 40. This is important because the inner surface 46 supports the rack 34 and unevenness or imperfections in the inner surface 46 can increase the wear of the bearing 40 and increase the frictional resistance to linear movement of the rack 34. is there.

  With reference to FIG. 7, the wall 66 of the bearing 40 includes an outer surface 68 and an inner surface 70. The outer surface 68 is defined by an outer radius 72. The outer surface 68 is generally circular and defines an outer circumference having a first center point 74. Wall 66 is further defined by an inner surface 70 having an inner radius 76. Inner surface 70 is generally circular and defines an inner circumference having a second center point 78. This second center point 78 thereby defines an amount of eccentricity between the outer circumference and the inner circumference that defines a change in the radial thickness of the wall 66. A certain distance interval is open. This varying radial thickness is gradual and, as will be discussed below, adjustment mechanism 38 allows gradual and smooth adjustment of bearing 40.

  As shown in FIGS. 4 and 7, the outer surface 68 of the bearing 40 contacts and engages the inner surface 46, where the inner surface 46 defines a second diameter 58. The outer surface 68 is slightly smaller than the second diameter 58 of the inner surface 46 so that the bearing 40 can be rotated by the adjustment mechanism 38 (as discussed below). As noted above, the first diameter 56 is centered on the longitudinal axis 42 and the second diameter 58 is centered on the second axis 60. This second axis 60 is offset from the longitudinal axis 42 and this offset can vary. However, as shown, this offset is approximately equal to the amount of eccentricity between the first and second center points 74, 78 of the wall 66 of the bearing 40 in the opposite direction. In other words, this offset is equal to and opposite the changing radial thickness of the wall 66. The first diameter 56 of the inner surface 46 is such that, as discussed below, when the bearing 40 is rotated by the adjustment mechanism 38 to move the rack 34 into proper mating engagement with the pinion 36, the rack 34 and housing Allow clearance between 32. The second axis 60 and thereby the second diameter 56 offset from the longitudinal axis 42 are important for applications where the size of the housing 32 is limited due to space issues and constraints within the application of the device 30. It is. The offset second shaft 60 combined with the varying radial thickness of the wall 66 of the bearing 40 still has sufficient clearance to adjust the position of the rack 34 by the adjustment mechanism 38, as discussed below. A smaller radial cross section of the housing 32 is considered.

  Referring to FIG. 8, the bearing 40 is operatively coupled to an adjustment mechanism 38 that rotates the bearing 40 relative to the longitudinal axis 42. Thus, the varying radial thickness of the wall 66 of the bearing 40 causes the rack 34 to move toward the pinion 36 and the radius of the supporting wall 66 as the radial thickness of the wall 66 supporting the rack 34 increases. Move away from pinion 36 when directional thickness decreases. The rack 34 rotates the bearing 40, thereby changing the radial thickness of the wall 66 that supports the rack 34, and the pinion 36 by an adjustment mechanism 38 that positions the rack 34 in proper mating engagement with the pinion 36. And moved relative to the housing 32. Thus, the bearing 40 adjusts the rack 34 by gradually moving relative to the longitudinal axis 42 as the bearing 40 is rotated by the adjustment mechanism 38. The changing radial thickness of the wall 66 is minimized at the radial position where the inner circumference is closest to the outer circumference.

  The wall 66 of the bearing 40 defines a hole 80 extending toward the distal end, which further defines a seat 82. The adjustment mechanism 38 is coupled to the seat 82 so that the bearing 40 can be push-pull rotated with respect to the movement of the adjustment mechanism 38, as indicated by a directional arrow 84. The hole 80 has an elliptical shape with a tapered diameter so as to enter a seat 82 that is generally conically bulging into a bulbous shape. The elliptical and geometrical conical shape of the hole 80 allows the adjustment mechanism 38 to pivot the seat 82. The geometry of the bore 80 is particularly important to allow the adjustment mechanism 38 to pivot as the bearing 40 rotates about the longitudinal axis 42 during adjustment of the bearing 40.

  The adjustment mechanism 38 preferably includes a fastener 86 or set screw for coupling with the seat 82 of the bearing 40. The fastener 86 includes a first end 88 that defines a bulged portion 90 and a shaft 92 that extends from the first end 88 to the second end 94. This swollen portion 90 of fastener 86 engages seat 82 of bearing 40. The fastener 86 pivots within the seat 82 of the bearing 40 as the bearing 40 rotates about the longitudinal axis 42 during adjustment of the bearing 40. The seat 82 of the bearing 40 can optionally include an annular protrusion 96 such that the bulged portion 90 of the fastener 86 creates and engages a coupling engagement between the fastener 86 and the bearing 40. This annular protrusion 96 helps provide a positive engagement so that the bearing 40 can rotate in two directions without the fastener 86 becoming disengaged from the seat 82 of the bearing 40. Thus, the bearing 40 is rotated in one direction with a pushing force when the fastener 86 is driven into the seat 82 and in the opposite direction with a pulling force when the fastener 86 is moved away from the seat 82. The second end 94 of the fastener 86 engages with the opening 48 in the housing 32 so that the fastener 86 can be tightened to push the bearing 40 and the fastener 86 can be loosened to pull the bearing 40. A threaded portion 98 is defined for mating. The bearing 40 rotates relative to the longitudinal axis 42 as the fastener 86 pivots at a seat 82 in the hole 80. FIG. 9 shows a cross-sectional view of housing 32 and bearing 40 with adjustment mechanism 38 including fasteners 86 to illustrate engagement between components of device 30. It should be understood that the adjustment mechanism 38 can be any suitable design.

  Optionally, the adjustment mechanism 38 can further include a coil spring 102 as shown in FIG. The coil spring 102 is disposed about the shaft 92 of the fastener 86 for biasing between the bearing 40 and the housing 32. This biasing by the coil spring 102 provides additional damping for play movement of the rack 34 relative to the pinion 36. In addition, the coil spring 102 provides a force that can further rotate the bearing 40 to maintain proper intermeshing engagement between the rack 34 and the pinion 36. The rotation of the bearing 40 by the coil spring 102 effectively provides motion adjustment to the bearing 40 when it is necessary to compensate for the additional clearance caused by the wear of the bearing 40 over time associated with the operation of the power steering device 30. .

  The damping mechanism 100 and the outer surface 68 of the bearing 40 provide a frictional force against the inner surface 46 that secures the bearing 40 in place. This frictional force provides a virtual fixation of the bearing 40 in place and does not rotate the bearing 40 even under high applied forces that compress the coil spring 102 and thereby rotate the bearing 40. Thus, adjustment of the bearing 40 by the coil spring 102 is effective to rotate the bearing 40 during operation of the device 30 and the friction caused by the contact surface between the outer surface 68 and the damping mechanism 100 having the inner surface 46. The force maintains the bearing 40 in place to prevent compression of the coil spring 102. However, the coil spring 102 can be removed, while providing an operative and continuous adjustment to the bearing 40 to compensate for the additional clearance caused by wear of the bearing 40 due to the operation of the device 30. One skilled in the art will appreciate that only additional optional devices can be provided to provide a way to further dampen play movement.

  Still referring to FIG. 10, the fastener 86 may further include a seal 103 for holding the fastener 86 against the housing 32. In alternative embodiments of the present invention, a lock tight or similar method known in the art can optionally be disposed on the screw, or the fastener 86 is held against the housing 32. Tolerance stacking can be used to achieve this.

  There are several embodiments of the bearing 40 shown in FIGS. Each of these embodiments is flexible to the wall 66 of the bearing 40 to create a variety of bearings 40 that are unique for certain applications, each having a different width of the wall 66, a scallop 114 design, and a cavity 116 arrangement. And design alternatives. The alternative embodiment of bearing 40 of FIG. 10 does not include scallop 114, however, fastener 86 uses a seal on fastener 86. This fastener 86 will engage an opening 48 in the housing 32 (not shown) to secure the fastener 86 to the device 30.

  Referring to FIG. 11, a third embodiment of the bearing 40 includes an increasing bearing 40 width that spans and supports a longer portion of the rack 34. The additional bearing 40 width thereby increases the load carrying capacity of the bearing 40 for supporting the rack 34 in meshing engagement with the pinion 36. An additional damping mechanism 100, in this embodiment an O-ring, is used to provide additional damping of play movement relative to the pinion 36 of the rack 34.

  FIG. 12 shows a fourth embodiment of the bearing 40 and includes an adapter 118 that rotatably engages the inner surface 70 of the bearing 40. The adapter 118 defines an orifice 120 having a configuration that is complementary to the configuration of the rack 34. Adapter 118 is typically used to support rack 34 having a Y-shaped rack configuration. The bearing 40 of this fourth embodiment is also a simpler tube without the additional machining of the offset second diameter 58 in which the inner surface 46 of the housing 32 is known in the art and discussed above. be able to. Adapter 118 is an additional component normally required for various power steering devices 30 using a Y-shaped rack configuration. As will also be appreciated by those skilled in the art, the orifice 120 of the adapter 118 can be optionally complementary to any rack configuration.

  13-16 illustrate a fifth embodiment of the bearing 40 that incorporates a cavity 116 that extends from the tip 106 of the bearing 40. However, this fifth embodiment does not include the scallop 114. Therefore, the bearing 40 is disposed in the chamber 44 next to the pinion 36.

  FIGS. 17-19 illustrate a sixth embodiment of a bearing 40 that incorporates a cavity 116 circumferentially around the tip 106. The cavity 116 extends along the longitudinal axis 42 toward the rear end 108 and is disposed between the outer surface 68 and the inner surface 70 of the bearing 40. Further, the bearing 40 includes a scallop 114 on the wall 66 of the bearing 40.

  FIGS. 20-22 illustrate a seventh embodiment of the bearing 40 that incorporates a series of cavities 116 that extend from the tip 106 of the bearing 40 along the longitudinal axis 42 toward the rear end 108. In addition, the bearing 40 can be positioned so that the scallop 114 extends longer into the wall 66 to reduce the width of the bearing 40, thereby directly opposing a portion of the wall 66 of the bearing 40 to the pinion 36 that engages the rack 34. .

  FIG. 23 shows an eighth embodiment of the bearing 40 having a series of cavities 116 extending from the tip 106 of the bearing 40. Further, this eighth embodiment shows that the size and angle of the scallop 114 can be varied to further reduce the width of the bearing 40 at a portion of the wall 66 of the scallop 114 and bearing 40. Those skilled in the art will appreciate that the load requirements and the design of the housing 32 require that the bearing 40 be flexible in order to place the bearing 40 within the housing 32 near the intermeshing engagement between the rack 34 and the pinion 36. Will understand.

  Obviously, many modifications and variations of the present invention are possible in light of the above teachings. The invention may be practiced otherwise than as specifically described within the scope of the appended claims.

1 is an elevational view of a housing for a power steering device according to a first embodiment of the present invention having a partial cutout. FIG. FIG. 2 is a transverse sectional view taken along a section line 2-2 in FIG. FIG. 2 is a detailed view taken along a perspective arrow 3 in FIG. 1. FIG. 4 is a cross-sectional view of the housing taken along section line 4-4 of FIG. It is a fragmentary perspective view of the rack and pinion of a power steering device. It is a fragmentary perspective view of the rack supported by the bearing and meshingly engaged with the pinion. It is a side view of the bearing shown in FIG. It is a fragmentary cross-sectional view which shows engagement between an adjustment mechanism and a bearing. FIG. 6 is a partial cross-sectional view showing the engagement between the bearing in the housing and the adjustment mechanism, the bearing, and the rack. It is a perspective view of 2nd Embodiment of the bearing which supports the rack which meshes and engages with a pinion. FIG. 9 is a top view of a third embodiment of a bearing that supports a rack that meshes and engages with a pinion. FIG. 10 is a side view of a fourth embodiment of a bearing that supports a rack having a Y-shaped configuration. FIG. 10 is a perspective view of a fifth embodiment of a bearing that supports a rack that meshes and engages with a pinion. It is a cross-sectional view of the bearing of the fifth embodiment. It is a cross-sectional perspective view of the bearing of 5th Embodiment. It is another cross-sectional perspective view of the bearing of 5th Embodiment. FIG. 10 is a cross-sectional view of a sixth embodiment of a bearing that supports a rack that meshes and engages with a pinion. It is a cross-sectional perspective view of the bearing of 6th Embodiment. It is another cross-sectional perspective view of the bearing of 6th Embodiment. FIG. 10 is a cross-sectional view of a seventh embodiment of a bearing that supports a rack that meshes and engages with a pinion. It is a cross-sectional perspective view of the bearing of 7th Embodiment. It is another cross-sectional perspective view of the bearing of 7th Embodiment. It is a perspective view of 8th Embodiment of the bearing which supports the rack which meshes and engages with a pinion.

Explanation of symbols

DESCRIPTION OF SYMBOLS 30 Power steering apparatus 32 Housing 34 Rack 36 Pinion 38 Adjustment mechanism 40 Bearing 42 Longitudinal axis 44 Chamber 46 Inner surface 50 Extension part 52 Groove 56 1st diameter 58 2nd diameter 60 2nd axis | shaft 62 Shoulder 64 Tooth 66 Wall 68 Outer surface 70 Inner surface 72 Outer radius 74 First center point 76 Inner radius 78 Second center point 80 Hole 82 Seat 84 Arrow 86 Fastener 88 First end 90 Swelled portion 92 Shaft 100 Damping mechanism 102 Coil spring 104 Orientation extension 106 tip 108 back end 110 finger 114 scallop 116 cavity
118 Adapter 120 Orifice

Claims (19)

A housing extending along the longitudinal axis and having a chamber with an inner surface;
A rack disposed within the chamber for movement along the longitudinal axis;
A pinion supported by the housing and extending into the chamber to mate with the rack;
A bearing that engages the inner surface of the chamber and is disposed about the rack and having a radially varying wall circumferentially surrounding the rack and continuously changing;
Supported by the housing and adjusts the bearing for rotation relative to the shaft so that the rack is relative to the pinion to ensure proper mating engagement with the rack. A power steering device including an adjustment mechanism coupled to the bearing.   The apparatus of claim 1, wherein the wall of the bearing further defines a bore that defines the seat extending toward a distal end and coupling the adjustment mechanism to the seat.   The adjustment mechanism has a first end defining a bulged portion for engaging the seat and an axis extending from the first end for engaging the housing to a second end. The apparatus of claim 2, further comprising a fastener having.   The apparatus of claim 3, wherein the seat further defines the annular protrusion for engaging the bulged portion of the fastener with an annular protrusion.   The apparatus of claim 3, wherein the adjustment mechanism further comprises a coil spring disposed about the axis of the fastener for biasing between the bearing and the inner surface.   The apparatus of claim 3, wherein the housing further includes an opening extending into the chamber for receiving the fastener of the adjustment mechanism.   The apparatus of claim 6, wherein the second end of the fastener further defines a threaded portion for engaging the opening of the housing.   The apparatus of claim 1, wherein the wall extends between a leading edge and a trailing edge along the longitudinal axis, and the trailing edge defines a stop that limits movement of the rack within the chamber.   The apparatus of claim 1, wherein the inner surface of the housing further includes a groove extending annularly about the longitudinal axis for positioning the bearing.   The apparatus of claim 9, wherein the bearing further includes a finger biased outwardly from the bearing for engaging in the groove to position the bearing in the chamber.   The wall has a leading end and a trailing end, and the trailing end further defines a series of alternating fingers and notches around the circumferential direction of the bearing, the series for positioning the bearing in the chamber. The device of claim 9, wherein the fingers are biased outwardly from the bearing to engage the groove.   The wall of the bearing includes an outer surface having an outer radius and an inner surface having an inner radius spaced a distance center from the outer radius to define the varying radial thickness of the wall. The apparatus according to 1.   The apparatus of claim 12, wherein the bearing further includes an adapter that rotatably engages the inner surface, the adapter defining an orifice having a configuration complementary to the configuration of the rack.   The wall of the bearing is defined by an outer surface defining an outer circumference having a first center point and an inner surface defining an inner circumference having a second center point, the varying radius of the wall; The apparatus of claim 1, wherein the second center point is eccentric from the first center point to define a directional thickness.   The apparatus of claim 14, wherein the varying radial thickness defines a minimum radial thickness where the inner circumference is closest to the outer circumference.   The apparatus of claim 1, wherein the bearing further includes a dampening mechanism for dampening idle movement between the rack and the pinion.   The wall further defines a bearing width extending between the leading and trailing ends, the leading end being inwardly along the longitudinal axis to allow the bearing to be positioned under the pinion. The apparatus of claim 1, further defined by at least one scallop extending toward the wall of the bearing.   The wall of claim 1, further comprising a directing extension for positioning the bearing relative to the housing during assembly of the bearing into the chamber. Equipment.   The wall further defines a bearing width extending between the leading and trailing ends, and the wall extends between the outer surface and the inner surface along the longitudinal axis between the outer surface and the inner surface to improve the hardening characteristics of the bearing. The apparatus of claim 1 further defining:

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