CN211778499U - Ball and socket assembly and solid axle assembly in a vehicle - Google Patents

Abstract

The utility model discloses a solid axle subassembly in ball socket assembly and vehicle. The ball and socket assembly includes a housing that is made as a unitary piece and has an internal bore. The ball and socket assembly also includes a ball stud having a hemispherical curved portion, a cylindrical portion, and a shank. The ball and socket assembly further includes a backing bearing and an outlet bearing. A third bearing is received on the cylindrical portion of the ball stud. The third bearing has a curved outer surface that mates with a curved inner surface of at least one of the outlet bearing and the backing bearing to allow the ball stud and the bearing to articulate and rotate relative to the housing. The third bearing is also in sliding contact with the cylindrical portion of the ball stud to allow the ball stud to rotate more freely about the central axis relative to the housing. The solid axle assembly in the vehicle includes an axle, a knuckle, and a pair of ball and socket assemblies.

Description

Ball and socket assembly and solid axle assembly in a vehicle

Cross Reference to Related Applications

This application claims the benefit of U.S. provisional application No. 62/670,035 filed on 2018, 5, month 11, the entire contents of which are incorporated herein by reference.

Background

1. Field of the invention

The present invention relates generally to ball and socket assemblies and, more particularly, to a ball and socket assembly for use in a solid axle suspension assembly of a vehicle.

2. Background of the invention

In a vehicle having a solid axle assembly, for each wheel, a pair of ball joints operatively attach the axle to the knuckle. The two ball joints are aligned with each other along a vertically extending axis and allow the knuckle to pivot about the axis in response to steering input from the driver, thereby turning the wheel to which the knuckle is attached. Each ball joint comprises: a housing; a ball stud having a ball portion; and at least one bearing that facilitates a low friction interface between the ball stud and the housing.

When the ball joints of the solid axle assembly are properly installed such that the center of sphere distances of the spherical portions are spaced a prescribed distance from each other along the vertically extending axis, the ball joints will generally equally share the axial load applied by the weight of the vehicle. However, if an incorrect installation occurs, one of the ball joints may be forced to bear all downward axial loads while the other ball joint is subjected to an upward load. In such a case where opposite axial loads are placed on these ball joints, an increase in rotational resistance or torque may be increased due to high contact pressure between the spherical portion of the ball stud and the bearing, thereby making steering more difficult.

SUMMERY OF THE UTILITY MODEL

One aspect of the present invention relates to a ball and socket assembly for use in a solid axle assembly. The ball and socket assembly includes a housing having an inner surface and a lower wall that are made as a unitary piece and surround an inner bore extending along a central axis. The ball and socket assembly also includes a ball stud having a hemispherical curved portion, a cylindrical portion, and a shank. The hemispherical curved portion and the cylindrical portion are disposed in the inner bore of the housing. The shank extends from the bore through an open end of the housing opposite the lower wall. The ball and socket assembly further includes a backing bearing and an outlet bearing, both received in the bore of the housing and both having respective curved inner surfaces. A third bearing is received on the cylindrical portion of the ball stud. The third bearing has a curved outer surface that mates with a curved inner surface of at least one of the outlet bearing and the backing bearing to allow the ball stud and the bearing to articulate and rotate relative to the housing. The third bearing is also in sliding contact with the cylindrical portion of the ball stud to allow the ball stud to rotate more freely about the central axis relative to the housing.

In the event that two ball studs are mis-installed in a solid axle assembly such that the vertical distance between the ball studs is not within a prescribed tolerance range, the third bearing allows relative rotation between the housing and the ball studs to continue with little or no restriction, as opposed to other known ball and socket assemblies in which the ball studs may be restricted from rotation.

According to another aspect of the present invention, a ball stud has a first planar surface extending between a hemispherical curved portion and a cylindrical portion; wherein the third bearing has a second planar surface; and wherein the first planar surface and the second planar surface are in face-to-face contact with each other.

According to yet another aspect of the invention, the third bearing is axially located between the backing bearing and the outlet bearing.

According to yet another aspect of the present invention, the third bearing is in a loose-fitting relationship with the cylindrical portion of the ball stud.

According to a further aspect of the invention, the washer spring is received in the bore of the housing and elastically deforms to exert an axial force on the outlet bearing to bias the curved inner surface of the outlet bearing against the curved outer surface of the third bearing.

In accordance with yet another aspect of the present invention, the hemispherical curved portion of the ball stud is generally hemispherical in shape.

Another aspect of the present invention relates to a solid axle assembly in a vehicle. The solid axle assembly includes an axle as described above, a steering knuckle, and a pair of ball and socket assemblies.

Yet another aspect of the present invention discloses a method of repairing a solid axle assembly. The method includes the step of removing a previously used ball and socket assembly from the opening of the axle or knuckle. The method continues with the step of inserting the socket into the opening. Particularly, the utility model discloses a method of repairing solid axle subassembly, this method includes following step: removing the previously used ball and socket assembly from the opening of the axle or knuckle; inserting a ball and socket assembly into the opening, the ball and socket assembly comprising: a housing having an inner surface and a lower wall fabricated as a unitary piece and surrounding an inner bore extending along a central axis; a ball stud having a hemispherical curved portion, a cylindrical portion, and a shank, the hemispherical curved portion and the cylindrical portion being disposed in the inner bore of the housing, and the shank protruding from the inner bore through an open end of the housing opposite the lower wall; a backing bearing and an outlet bearing received in the bore of the housing, both the backing bearing and the outlet bearing having respective curved inner surfaces; a third bearing received on the cylindrical portion of the ball stud and having a curved outer surface that mates with the curved inner surface of at least one of the outlet bearing and the backing bearing to allow the ball stud and the third bearing to articulate and rotate relative to the housing; and, the third bearing is in sliding contact with the cylindrical portion of the ball stud to allow the ball stud to rotate more freely about the central axis relative to the housing. According to an embodiment, in the method, the ball stud has a first planar surface extending between the hemispherical curved portion and the cylindrical portion, wherein the third bearing has a second planar surface, and wherein the first and second planar surfaces are in face-to-face contact with each other.

Drawings

These and other features and advantages of the present invention will become more readily appreciated when considered in connection with the following description of the presently preferred embodiments, the appended claims and the accompanying drawings in which:

FIG. 1 is a perspective view and partially exploded view of a solid axle suspension assembly including a pair of ball joints constructed in accordance with one aspect of the present invention;

FIG. 2 is a front elevational view of one of the ball joints of FIG. 1;

FIG. 3 is an exploded and partial cross-sectional view of the ball joint of FIG. 2;

FIG. 4 is a cross-sectional view of a housing of the ball joint of FIG. 2;

FIG. 5 is a cross-sectional view of the ball joint of FIG. 2;

FIG. 6 is an enlarged view of a portion of the ball joint of FIG. 5;

FIG. 7 is another enlarged view of a different portion of the ball joint of FIG. 5; and is

Fig. 8 is a cross-sectional and fragmentary view of the ball joint of fig. 5 and illustrating a lubrication flow path.

Detailed Description

Referring to the drawings, wherein like numerals indicate corresponding parts throughout the several views, FIG. 1 generally shows a solid axle assembly 20 for a vehicle. As shown, the solid axle assembly 20 includes a steering knuckle 24 that extends transversely through an axle 22 and a support hub (not shown) of the vehicle. A pair of ball and socket assemblies (hereinafter referred to as ball joints 26) operatively attach the steering knuckle 24 to the axle 22. The ball joints 26 have respective ball studs 28 that are aligned with one another along a common vertical axis to allow the steering knuckle 24 to pivot about the vertical axis relative to the axle 22 in response to steering inputs from the vehicle operator. The ball joints 26 preferably have the same or similar configuration to reduce errors in installing the ball joints 26 in the solid axle assembly 20. Each ball joint 26 has a housing 30 fixedly attached to either the knuckle 24 or the axle 22 and a ball stud 28 fixedly attached to the other of the knuckle or the axle.

Referring now to fig. 3, for each of the ball joints 26, the housing 30 has an inner surface that surrounds an inner bore extending along the central axis a from a lower wall 32 at a closed first end of the housing 30 to an open second end of the housing 30. The lower wall 32 has a lubricant opening that receives a grease fitting 34 (also referred to as a nipple fitting) for delivering lubricant, such as grease, into the internal bore to initially lubricate the components of the ball joint 26 and to re-lubricate the ball joint 26 as part of routine maintenance. The housing 30 is preferably made as a unitary piece of metal, such as steel or alloy steel, and may be formed by any suitable process or by a combination of processes including, for example, forging, casting, machining, and the like. In the exemplary embodiment, housing 30 has a barrel configuration that is configured for press-fitting into an opening in axle 22 (shown in FIG. 1) or knuckle 24 (also shown in FIG. 1).

As shown in fig. 4, the inner bore of the housing 30 has a gradually increasing diameter from the lower wall 32 to the open second end. Specifically, the inner bore has, in series, a first portion 36 having a generally constant first diameter D1 adjacent the lower wall 32, a second portion 38 having a gradually increasing diameter, and a third portion 40 having a generally constant second diameter D2 adjacent the open second end. As shown, the second diameter D2 of the third portion 40 is greater than the first diameter D1 of the first portion 36. In the second portion 38, the inner surface of the housing 30 is curved to increase the diameter of the second portion 38 in the axial direction toward the open second end. Between the second and third portions 38, 40 of the bore, the housing 30 presents a shoulder 42 facing the open second end.

Referring back to fig. 3, the ball joint 26 includes a backing bearing 44 and an outlet bearing 46 disposed in the inner bore of the housing 30. The backing bearing 44 and the outlet bearing 46 have respective hemispherical curved bearing surfaces 48, 50 that are shaped to provide a low friction interface between the housing 30 and the ball stud 28, allowing the housing 30 and the ball stud 28 to rotate and articulate relative to each other during operation of the vehicle.

The backing bearing 44 is received in the first portion 36 of the bore and has a hemispherical curved first bearing surface 48 facing axially toward the open second end of the housing 30. The backing bearing 44 also has an outer surface with an outer diameter that is less than the first diameter D1 (also shown in fig. 4) of the first portion 36 (shown in fig. 4) such that a gap (exaggerated in fig. 6) exists between the outer surface of the backing bearing 44 and the inner surface of the housing 30. Thus, the backing bearing 44 is allowed to float in a radial direction within the first portion 36 of the bore within the confines established by the gap. The backing bearing 44 also includes a lubricant opening that is aligned with the lubricant opening of the lower wall 32 of the housing 30. The first bearing surface 48 of the exemplary embodiment is provided with a plurality of first grooves formed thereon for distributing lubricant from the lubricant openings into the second portion 38 of the bore.

A thrust washer 52 is positioned in the first portion 36 of the bore between the backing bearing 44 and the lower wall 32 of the housing 30 to provide a low friction interface between the backing bearing 44 and the lower wall 32, allowing the backing bearing 44 to move more freely within the bore of the housing 30. In the exemplary embodiment, a lower surface of backing bearing 44 opposite curved first bearing surface 48 presents a plurality of lubricant channels for transporting lubricant between backing bearing 44 and thrust washer 52 to further reduce friction between backing bearing 44 and thrust washer 52. The thrust washer 52 is preferably made of a metal or polymer material and may be formed by any suitable process.

The ball stud 28 has a cylindrical portion 54, a shank portion 56 and a hemispherical curved portion 58. In the exemplary embodiment, the hemispherical curved portion is generally hemispherical in shape (i.e., approximately half a sphere), and is therefore referred to hereinafter as "hemispherical portion 58". The hemispherical portion 58 and the cylindrical portion 54 are disposed entirely within the internal bore of the housing 30, and the stem 56 projects from the internal bore through the open second end of the housing 30. The ball stud 28 also has a first planar surface 60 that is annular in shape and extends approximately between the equator of the hemispherical portion 58 and the cylindrical portion 54. When the ball stud 28 is in the vertical orientation shown in fig. 5, the first planar surface 60 is in a plane perpendicular to the central axis a. In the axial direction, the cylindrical portion 54 has a constant diameter from the first planar surface 60 to the shank 56. The shank 56 extends to a distal end that is threaded for receiving a nut to fixedly attach the ball stud 28 to the axle 22 (shown in FIG. 1) or the knuckle 24 (also shown in FIG. 1).

A third bearing 62 extends annularly around the cylindrical portion 54 of the ball stud 28, which is made as a separate piece from the ball stud 28. In the axial direction, the third bearing 62 is located between the backing bearing 44 and the outlet bearing 46. The third bearing 62 has a curved outer surface with a radius of curvature similar to the hemispherical portion 58 of the ball stud 28. Thus, the third bearing 62 and the hemispherical portion 58 of the ball stud 28 together define a spherical or substantially hemispherical shape. The third bearing 62 has a second planar surface 64 that is annular in shape and in face-to-face and sliding contact with the first planar surface 60 of the ball stud 28. The third bearing 62 is in a clearance or loose fit relationship with the ball stud 28 such that it can freely rotate about the ball stud 28 about the central axis a. The third bearing 62 is preferably fabricated as a unitary piece of metal (such as steel or alloy steel) and may be formed by any suitable operation.

A radial ring 66 is positioned in the third portion 40 of the bore and abuts the shoulder 42 of the housing 30. The radial ring 66 is a separate piece from the backing bearing 44 and is axially spaced from the backing bearing by a gap in the second portion 38 of the bore. The radial ring 66 is annular in shape and has a radially inward surface that is in sliding contact with the hemispherical portion 58 of the ball stud 28 and/or the third bearing 62 for transmitting radial forces between the ball stud 28 and the housing 30. In the exemplary embodiment, an inner surface of radial ring 66 includes a plurality of lubrication grooves that are configured to axially transport lubricant within the bore through radial ring 66. The gap between the backing bearing 44 and the radial ring 66 acts as a lubrication reservoir to hold lubricant.

The outlet bearing 46 is received in the third portion 40 of the bore and its curved second bearing surface 50 is in sliding contact with the curved outer surface of the third bearing 62 to allow the third bearing 62 and the ball stud 28 to rotate and articulate relative to the housing 30 during vehicle operation. In the exemplary embodiment, curved second bearing surface 50 of outlet bearing 46 has a plurality of lubrication grooves for distributing lubricant over the contact surface between outlet bearing 46 and third bearing 62. The outlet bearing 46 has a generally flat or planar top surface facing toward the open second end of the housing 30.

This arrangement of components inside the bore ensures that the radial ring 66 transmits all or substantially all of the radial forces between the ball stud 28 and the housing 30, while the backing bearing 44 and the outlet bearing 46 transmit all or substantially all of the axial forces between the ball stud 28 and the housing 30 during vehicle operation.

The ball joint 26 further includes a dust shield 68 that seals against the housing 30 and against the shank 56 of the ball stud 28 to maintain lubricant in the interior of the ball joint 26 and to keep contaminants outside of the ball joint 26. The dust boot 68 includes a first boot end presenting a radially outwardly extending flange having a spring 70 (best shown in fig. 7) in the form of a Belleville washer 70 (also referred to as a washer spring) that is encapsulated within the boot body at the radially outwardly extending flange. The radially outwardly extending flange is in face-to-face contact with the flat top surface of the outlet bearing 46. The boot is made of a flexible sealing material, such as a rubber or plastic material, to allow the dust boot 68 to flex as the housing 30 and ball stud 28 articulate relative to one another and maintain the seal established thereby.

The cover plates 72 are positioned at opposite sides of the radially outwardly extending flange of the dust cover 68. Housing 30 is deformed (such as by swaging) to present a radially inwardly extending lip 74 that traps cover plate 72 and the radially outwardly extending flange of dust shield 68 between radially inwardly extending lip 74 and outlet bearing 46. Deforming the housing 30 also has the effect of resiliently compressing the belleville washer 70 to exert a preload force on the outlet bearing 46 to bias the curved bearing surface of the outlet bearing 46 and thus the curved second outer surface 50 of the third bearing 62.

In the event that two ball joints 26 are mis-installed in the solid axle assembly 20 such that the vertical distance between the ball studs 28 is not within a prescribed tolerance range, one of the ball studs 28 will eventually absorb all or substantially all of the vertical load from the weight of the vehicle. If this happens, in a ball joint 26 carrying a large load, the axial load will be concentrated in only a small part of the contact surface between the third bearing 62 and the outlet bearing 46, creating a very high pressure at this location. Such pressure may limit relative rotation between the third bearing 62 and the housing 30. However, due to the relatively large surface-to-surface contact area between the first and second planar surfaces 60, 64 of the ball stud 28 and the third bearing 62, respectively, relative rotation between the ball stud 28 and the housing 30 is still possible without excessive friction. Thus, the third bearing 62 allows the ball stud 28 and the housing 30 to still rotate relative to each other. The cylindrical shape of the cylindrical portion 54 of the ball stud 28 ensures that all axial forces between the third bearing 62 and the ball stud 28 are transferred between and distributed across the first planar surface 60 and the second planar surface 64.

Another aspect of the present disclosure relates to a method of repairing a solid axle assembly 20, such as the solid axle assembly 20 shown in fig. 1. The method includes the step of removing a previously worn ball joint from an opening in the axle 22 or knuckle 24. The method continues with the step of inserting a new ball joint 26, such as the ball joint 26 discussed above and shown in fig. 2-8, into the opening.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings, and may be practiced otherwise than as specifically described while within the scope of the appended claims. Furthermore, it should be understood that the claims and all features of all embodiments may be combined with each other as long as they do not contradict each other. It will be further understood that the use of directional terms such as "top," "bottom," "upper" and "lower" are used with reference to the orientation of certain features in the drawings, and are not intended to require any particular orientation.

Claims (13)

1. A ball and socket assembly, comprising:

a housing having an inner surface and a lower wall fabricated as a unitary piece and surrounding an inner bore extending along a central axis;

a ball stud having a hemispherical curved portion, a cylindrical portion, and a shank, the hemispherical curved portion and the cylindrical portion being disposed in the bore of the housing, and the shank projecting from the bore through an open end of the housing opposite the lower wall;

a backing bearing and an outlet bearing received in the bore of the housing, both the backing bearing and the outlet bearing having respective curved inner surfaces;

a third bearing received on the cylindrical portion of the ball stud and having a curved outer surface that mates with the curved inner surface of at least one of the outlet bearing and the backing bearing to allow articulation and rotation of the ball stud and the third bearing relative to the housing; and is

The third bearing is in sliding contact with the cylindrical portion of the ball stud so as to allow the ball stud to rotate more freely about the central axis relative to the housing.

2. The ball and socket assembly of claim 1, wherein the ball stud has a first planar surface extending between the hemispherical curved portion and the cylindrical portion, wherein the third bearing has a second planar surface, and wherein the first and second planar surfaces are in face-to-face contact with each other.

3. The ball and socket assembly of claim 1, wherein the third bearing is axially located between the backing bearing and the outlet bearing.

4. The ball and socket assembly of claim 1, wherein said third bearing is in a loose-fitting relationship with said cylindrical portion of said ball stud.

5. The ball and socket assembly of claim 1, further comprising a washer spring received in the bore of the housing and elastically deformed to exert an axial force on the outlet bearing to bias the curved inner surface of the outlet bearing against the curved outer surface of the third bearing.

6. The ball and socket assembly of claim 1, wherein said hemispherical curved portion of said ball stud is generally hemispherical in shape.

7. The ball and socket assembly of claim 1, wherein the third bearing is axially located between the backing bearing and the exit bearing.

8. A solid axle assembly in a vehicle, comprising:

an axle;

a knuckle;

a pair of ball and socket assemblies operatively connecting the steering knuckle to the axle and allowing the steering knuckle to rotate about a vertical axis relative to the axle; and is

Each of the ball and socket assemblies includes:

a housing having an inner surface and a lower wall fabricated as a unitary piece and surrounding an inner bore extending along a central axis;

a ball stud having a hemispherical curved portion, a cylindrical portion, and a shank, the hemispherical curved portion and the cylindrical portion being disposed in the bore of the housing, and the shank projecting from the bore through an open end of the housing opposite the lower wall;

a backing bearing and an outlet bearing received in the bore of the housing, both the backing bearing and the outlet bearing having respective curved inner surfaces;

a third bearing received on the cylindrical portion of the ball stud and having a curved outer surface that mates with the curved inner surface of at least one of the outlet bearing and the backing bearing to allow articulation and rotation of the ball stud and the third bearing relative to the housing; and is

The third bearing is in sliding contact with the cylindrical portion of the ball stud so as to allow the ball stud to rotate more freely about the central axis relative to the housing.

9. A solid axle assembly in a vehicle as defined in claim 8, wherein said ball stud has a first planar surface extending between said hemispherical curved portion and said cylindrical portion, wherein said third bearing has a second planar surface, and wherein said first and second planar surfaces are in face-to-face contact with each other.

10. The solid axle assembly in a vehicle of claim 8 wherein said third bearing is axially located between said backing bearing and said outlet bearing.

11. A solid axle assembly in a vehicle as set forth in claim 8 wherein said third bearing is in a loose-fitting relationship with said cylindrical portion of said ball stud.

12. A solid axle assembly in a vehicle as set forth in claim 8 further comprising a washer spring received in said bore of said housing and resiliently deforming to exert an axial force on said outlet bearing to bias said curved inner surface of said outlet bearing against said curved outer surface of said third bearing.

13. A solid axle assembly in a vehicle as set forth in claim 8 wherein said hemispherical curved portion of said ball stud is generally hemispherical in shape.

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