WO2009003000A1

WO2009003000A1 - Method and apparatus for preventing hub and bearing separation

Info

Publication number: WO2009003000A1
Application number: PCT/US2008/068109
Authority: WO
Inventors: Mircea Gradu; Mark A. Joki; Andrew W. Alley; Russell F. Folger; Steven A. Roman
Original assignee: The Timken Company
Priority date: 2007-06-26
Filing date: 2008-06-25
Publication date: 2008-12-31

Abstract

A vehicle wheel hub and bearing assembly (A) configuration which prevent axial separation of rotating hub components (4) and stationary housing components (2) in at least one axial direction via physical interference between radially inner most components of said stationary housing (2) and radially outermost components of said rotating hub (4), reducing the risk of vehicle wheel separation failures.

Description

METHOD AND APPARATUS FOR PREVENTING HUB AND BEARING SEPARATION

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is related to, and claims priority from, U.S. Provisional

Patent Application Serial No. 60/946,286 filed on June 26, 2007, and which is herein incorporated by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH Not Applicable. BACKGROUND OF THE INVENTION

The present application is related generally to vehicle wheel ends which include wheel hub and bearing assemblies, and in particular, to improvements to a vehicle wheel hub and bearing assembly configuration which prevent separation of the hub and bearing components, reducing the risk of vehicle wheel separation failures.

For some vehicle front wheel applications failures may occur in the vehicle wheel end to which the vehicle wheels are secured, which allow a wheel to separate from the vehicle. A typical wheel end has a housing that is bolted against a steering knuckle or other suspension upright, a hub provided with a flange to which a road wheel is attached and also a spindle that projects from the flange into the housing, and an antifriction bearing located between the housing and the hub spindle to enable the hub to rotate in the housing with minimal friction. Failure in the antifriction bearing can result in axial movement of the bearing cup relative to the bearing cone or inner race components. Sufficient axial movement will eventually result in a separation failure of the vehicle wheel, as the hub spindle axially separates from the hub housing.

Accordingly, it would be advantageous to provide a vehicle wheel end hub and bearing assembly which includes features which prevent separation failure of the vehicle wheel due to failure in the antifriction bearings. -?-

BRIEF SUMMARY OF THE INVENTION

Briefly stated, the present disclosure provides a vehicle wheel hub and bearing assembly configuration which prevent separation of the hub and bearing components via physical interference, reducing the risk of vehicle wheel separation failures. Axial components are provided in the assembly which incorporate end flanges having outer diameters which are greater than an inner diameters of an associated bearing cup component, whereby axial movement of the bearing cup component which may lead to separation of the hub from the housing is precluded.

In an alternate embodiment of the vehicle wheel end hub and bearing assembly of the present disclosure, an annular shield is disposed adjacent a large rib portion of the bearing inner race, the annular shield having an outer diameter which is greater than an inner diameter of an associated bearing cup component, whereby axial movement of the bearing cup component which may lead to separation of the hub from the housing is precluded. In an alternate embodiment of the vehicle wheel end hub and bearing assembly of the present disclosure, an annular snap ring is disposed at the inner diameter of the bearing cup, the annular snap ring having an inner diameter which is less than an outer diameter of an associated bearing inner race component, whereby axial movement of the bearing cup component which may lead to separation of the hub from the housing is precluded.

In an alternate embodiment of the vehicle wheel end hub and bearing assembly of the present disclosure, an inner race large rib is configured with an outer diameter which is greater than an inner diameter of an associated bearing cup component, whereby axial movement of the bearing cup component which may lead to separation of the hub from the housing is precluded.

In an alternate embodiment of the vehicle wheel end hub and bearing assembly of the present disclosure, an roll formed outer end of the hub spindle is configured with an outer diameter which is greater than an inner diameter of an associated bearing cup component, whereby axial movement of the bearing cup component which may lead to separation of the hub from the housing is precluded. In an alternate embodiment of the vehicle wheel end hub and bearing assembly of the present disclosure, the inner diameter of the bearing cup is configured to be less than an outer diameter of an associated bearing inner race component, whereby axial movement of the bearing cup component which may lead to separation of the hub from the housing is precluded.

The foregoing features, and advantages set forth in the present disclosure as well as presently preferred embodiments will become more apparent from the reading of the following description in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS In the accompanying drawings which form part of the specification:

Figure 1 is a section view of a prior art wheel end hub and bearing assembly;

Figure 2 is a sectional view of a first embodiment of a hub and bearing assembly of the present disclosure, incorporating an axial stub shaft;

Figure 3 is a sectional view of an alternate embodiment of the hub and bearing assembly of the present disclosure, incorporating an axial roll formed sleeve;

Figure 4 is a sectional view of an alternate embodiment of the hub and bearing assembly of the present disclosure, incorporating an annular roll formed shield; Figure 5 is a sectional view of an alternate embodiment of the hub and bearing assembly of the present disclosure, incorporating a snap ring mounted to the cup inner diameter;

Figure 6 is a sectional view of an alternate embodiment of the hub and bearing assembly of the present disclosure, illustrating an increased large rib outer diameter;

Figure 7 is a sectional view of an alternate embodiment of the hub and bearing assembly of the present disclosure, illustrating an increased roll-form outer diameter; and Figure 8 is a sectional view of an alternate embodiment of the hub and bearing assembly of the present disclosure, illustrating a cup inner diameter flat modification.

Corresponding reference numerals indicate corresponding parts throughout the several figures of the drawings. It is to be understood that the drawings are for illustrating the concepts set forth in the present disclosure and are not to scale. DESCRIPTION OF THE PREFERRED EMBODIMENT

The following detailed description illustrates the invention by way of example and not by way of limitation. The description enables one skilled in the art to make and use the present disclosure, and describes several embodiments, adaptations, variations, alternatives, and uses of the present disclosure, including what is presently believed to be the best mode of carrying out the present disclosure.

Referring to the drawings, a conventional wheel end A is shown in Figure 1 . The wheel end A is in essence a bearing assembly which couples a road wheel R to a suspension system component S of an automotive vehicle, and enables the road wheel R to rotate about an axis X and to transfer radial loads, and thrust loads in both axial directions, between the wheel R and suspension system component S. If the road wheel R steers the vehicle, the suspension system component S takes the form of a steering knuckle. If it does not steer, the suspension system component S may be a simple suspension upright. The wheel end A includes a housing 2 that is bolted to the suspension system component S, a hub 4 to which the road wheel R is attached, and a bearing 6 located between the housing 2 and hub 4 to enable the latter to rotate with respect to the former about the axis X with minimal friction.

The housing 2, which is a fixed member, includes a generally cylindrical body 10, which is tubular, and a plurality of lugs or ears 12 that project radially from the body 10, generally midway between the ends of the cup or tubular body 10. The inboard segment of the cup or tubular body 10 is received in the suspension system component S such that the ears 12 come against the component S, to which they secured with cap screws 14 that pass through the component S and thread into bores 16 in the ears 12. Thus, the wheel end A is attached to the suspension system component S at the ears 12 of its housing 2.

The hub 4, which is a rotatable member, includes a spindle 20, which extends through the tubular body 10 of the housing 2, and a flange 22 that is formed integral with the spindle 20 at the outboard end of the spindle 20. The flange 22 is fitted with lug bolts 24 over which lug nuts 26 thread to secure a brake disk 28 and the road wheel R to the hub 4.

The spindle 20 merges with the flange 22 at an enlarged region 30 that leads out to a cylindrical bearing seat 34 that in turn leads out to a formed end 36. The formed end 36 is directed outwardly away from the axis X and provides an inside face 38 that is squared off with respect to the axis X and is presented toward the enlarged region 30.

The bearing 6 lies between the spindle 20 of the hub 4 and the housing 2 and enables the hub 4 to rotate relative to the housing 2 about the axis X. It includes (FIG. 1 ) two outer raceways 40 and 42 formed on the interior surface of the cup or tubular body 10 for the housing 2, the former being outboard and the latter being inboard. The two raceways 40 and 42 taper downwardly toward each other so that they have their least diameters where they are closest, generally midway between the ends of the housing 2. Apart from the two outer raceways 40 and 42, the bearing 6 also includes an inner raceway 44 and thrust rib 46 that are on the enlarged region 30 of the spindle 20. The raceway 44 lies at the outboard position and faces the outboard outer raceway 40, tapering in the same direction downwardly toward the center of the housing 2. The thrust rib 46 extends along the large end of the raceway 44. Beyond the opposite small end of the raceway 44, the bearing 6 has a shoulder 48 that faces away from the flange 22 and toward the inside face 38 of the formed end 36.

The bearing 6 also includes an initially separate inner race in the form of a cone 50 that fits over the bearing seat 34 of the spindle 20 with an interference fit. It includes a raceway 52 that is presented outwardly toward the inboard outer raceway 42 on the housing 2 and tapers in the same direction, downwardly toward the middle of the housing 2. At the large end of its raceway 52 the cone 50 has a thrust rib 54 that leads out to a back face 56 that is squared off with respect to the axis X. At the small end of its raceway 52 the cone 50 has a retaining rib 58 and an integral extension 60 that leads toward the shoulder 48 on the enlarged region 30. Completing the bearing 6 are rolling elements in the form of tapered rollers 62 organized in two rows, one located between and contacting the outboard raceways 40 and 44 and the other located between and contacting the inboard raceways 42 and 52. The rollers 62 of each row are on apex. Thus, the conical envelopes in which the outboard raceways 42 and 46 and outboard rollers 62 lie have their apices at a common point along the axis, and likewise the conical envelopes in which the inboard raceways 42 and 52 and the inboard rollers 62 lie have their apices at another common point along the axis X. The rollers 62 of each row are separated by a cage 64 that maintains the proper spacing between the rollers 62 and further retains them in place around their respective inner raceways 44 and 52 in the absence of the housing 2.

The cone 50 fits over the bearing seat 34 of the spindle 20 with an interference fit and there lies captured between the enlarged region 30 of the spindle 20 and the formed end 36 of the spindle 20. Indeed, its back face 56 bears against the inside face 38 of the formed end 36, while the front end of its extension 60 bears against the shoulder 48 at the end of the enlarged region 30 of the spindle 20. The length of the cone extension 60 determines the setting for the bearing 6, and that is one of light preload. Thus, the bearing 6 contains no internal clearances.

The housing 2 at its ends contains seals 68 which close the ends of the bearing 6 and prevent contaminants from entering the bearing 6, while retaining a lubricant in the bearing 6.

Initially, the hub 4 does not have the formed end 36 at the inboard end of its spindle 2. Instead, it is manufactured with a deformable end that forms an extension of the bearing seat 34. It is deformed outwardly once the inboard cone 50 is fitted over it. U.S. Patent Nos. 6,443,622 and 6,532,666, which are incorporated herein by reference, disclose procedures for providing the formed end 36. Turning to Figures 2 and 3, in first and second embodiments of the vehicle wheel end hub and bearing assembly configurations of the present disclosure, axial components are provided which incorporate end flanges having outer diameters which are greater than an inner diameters of the bearing cup component, whereby axial movement of the bearing cup component which may lead to separation of the hub from the housing is precluded. Specifically, as shown in Figure 2, a stub shaft 100 is secured within the axis of the hub 4. The stub shaft 100 includes an annular flange 102 at an inboard end 104 which has a radial dimension (indicated as SS) which exceeds the radial distance from the axis X to the innermost surface of the cup or tubular body 10. Similarly, in Figure 3, the axially disposed stub shaft 100 is replaced with an axially disposed sleeve member 200 having an annular flange 202 at an inboard end 204 which has a radial dimension SS which exceeds the radial distance from the axis to the innermost surface of the cup or tubular body 10. The outboard end 206 of the sleeve 200 is roll formed over the peripheral edges of the hub bore, securing the sleeve 300 in place about the hub axis X.

With both the axial stub shaft 100 shown in Figure 2, and the axial sleeve 200 shown in Figure 3, the annular flanges 102, 202 disposed at the inboard ends provide a positive interference with the bearing cup component 50 in the event of axial movement between the bearing cup 10 and the hub spindle 20. This positive interference prevents the hub spindle 20 from separating from the bearing cup 10 and housing 2, thereby preventing wheel separation failure due to a failure of components within the bearing assembly.

As shown in Figure 4, in a third embodiment of the vehicle wheel end hub and bearing assembly of the present disclosure, an annular shield 300 is disposed adjacent the back face of the inner race or cone 50, the annular shield having an outer diameter which is greater than an inner diameter of the bearing cup component 10, whereby axial movement of the bearing cup component 10 which may lead to separation of the hub 20 from the housing 2 is precluded. The annular shield 300 is preferably retained between the back face 56 of the inner race or cone and the inside face 38 of the formed end 36. In a fourth embodiment of the vehicle wheel end hub and bearing assembly of the present disclosure, shown in Figure 5, an annular snap ring 400 is disposed at the inner diameter of the bearing cup 10, the annular snap ring 400 having an inner diameter which is less than an outer diameter of an associated inner race or cone 50, whereby axial movement of the bearing cup component 10 which may lead to separation of the hub 20 from the housing 2 is precluded by physical interference with the annular snap ring 400.

Turning to Figure 6, a fifth embodiment of the vehicle wheel end hub and bearing assembly of the present disclosure includes an enlarged inner race large rib end 500 which is configured with an outer diameter which is greater than an inner diameter of an associated bearing cup component 10, whereby axial movement of the bearing cup component 10 which may lead to separation of the hub 20 from the housing 2 is precluded by physical interference between the components.

In a sixth embodiment of the vehicle wheel end hub and bearing assembly of the present disclosure, shown in Figure 7, the roll formed outer end 36 of the hub spindle is configured with an extended portion 600 extending radially outward past the cone 50, and which has an outer diameter exceeding an innermost inner diameter of an associated bearing cup component 10, whereby axial movement of the bearing cup component 10 which may lead to separation of the hub 20 from the housing 2 is precluded by physical interference between the components.

Turning to Figure 8, a seventh embodiment of the vehicle wheel end hub and bearing assembly of the present disclosure is shown in which the inner diameter of the bearing cup 10 is configured to be less than an outer diameter of the bearing inner race component 50, whereby axial movement of the bearing cup component 10 which may lead to separation of the hub 20 from the housing 2 is precluded by physical interference between the components.

As various changes could be made in the above constructions without departing from the scope of the disclosure, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. Those of ordinary skill in the art will recognize that a variety of different configurations of the present invention may be utilized, each of which commonly utilizes a physical interference between the inner diameter of the bearing cup component 20 and an outer diameter associated with the bearing hub 20 to prevent axial separation of the hub 20 from the bearing housing 2.

Claims

CLAIMS:

1 . A vehicle wheel end assembly for coupling a rotating wheel to a suspension system component of an automotive vehicle, including a stationary housing, a rotating hub, and a bearing assembly disposed between the housing and the hub to enable rotation of the hub about an axis relative to the housing, wherein said rotating hub is prevented from separating axially from said housing by an interference between an outer diameter of at least one hub component and an inner diameter of at least one housing component.

2. The vehicle wheel end assembly of Claim 1 wherein said at least one hub component is an axial stub shaft coupled to the hub, said stub shaft having an annular flange on at least one end, and wherein said at least one housing component is a bearing outer cup having a portion with an inner diameter which is less than an outer diameter of said annular flange.

3. The vehicle wheel end assembly of Claim 1 wherein said at least one hub component is an axial sleeve having an annular flange on at least one end, and wherein said at least one housing component is a bearing outer cup having a portion with an inner diameter which is less than an outer diameter of said annular flange.

4. The vehicle wheel end assembly of Claim 1 wherein said at least one hub component is an annular shield member coupled to said hub adjacent a bearing cone back face, and wherein said at least one housing component is a bearing outer cup having a portion with an inner diameter which is less than an outer diameter of said annular shield.

5. The vehicle wheel end assembly of Claim 1 wherein said at least one hub component is a bearing cone large rib and wherein said at least one housing component is an annular snap ring seated at an inner diameter of a bearing outer cup, an inner diameter of said annular snap ring being less than an outer diameter of said bearing cone large rib.

6. The vehicle wheel end assembly of Claim 1 wherein said at least one hub component is a bearing cone large rib and wherein said at least one housing component is an inner diameter surface of a bearing cup, said bearing cone large rib having an outer diameter which exceeds an inner diameter of said inner diameter surface of said bearing cup.

7. The vehicle wheel end assembly of Claim 1 wherein said at least one hub component is an extended annular flange disposed at an axial end of said hub and wherein said at least one housing component is an inner diameter surface of a bearing cup, said extended annular flange having an outer diameter which exceeds an inner diameter of said inner diameter surface of said bearing cup.

8. A bearing assembly for coupling a rotating component having an axis of rotation to a stationary component, including a stationary housing, a rotating hub disposed coaxially within said stationary housing, and a bearing assembly disposed between the housing and the hub to enable rotation of the hub about the axis of rotation relative to the housing, wherein axial separation of said rotating hub relative to said stationary housing in at least one axial direction is prevented, upon a selected amount of axial displacement there between, by an axially interfering engagement between a portion of at least one rotating hub component having an outermost diameter and a portion of at least one stationary housing component having an innermost diameter

9. A method for preventing axial separation of a rotating hub assembly and stationary housing assembly in a bearing arrangement for coupling a rotating component having an axis of rotation to a stationary component via rotating bearing elements disposed between the housing and the hub, comprising positioning said rotating hub assembly coaxially within said stationary housing assembly to contain said rotating bearings there between to enable rotation of the hub assembly about the axis of rotation relative to the housing assembly; upon a predetermined axial displacement of said rotating hub assembly in at least a first axial direction, axially abutting at least one component of said rotating hub assembly having a greatest outer diameter against at least one component of said stationary housing assembly having smallest inner diameter, said smallest inner diameter being less than said greatest outer diameter, whereby an axial interference is established and further axial displacement in said first direction is prevented by said axial interference.