WO2007134157A2

WO2007134157A2 - Driving wheel assembly

Info

Publication number: WO2007134157A2
Application number: PCT/US2007/068649
Authority: WO
Inventors: Mark A. Joki
Original assignee: The Timken Company
Priority date: 2006-05-10
Filing date: 2007-05-10
Publication date: 2007-11-22
Also published as: WO2007134157A3

Abstract

A coupling arrangement for transferring drive torque between a constant velocity joint (3) and a vehicle drive wheel hub (2). The coupling arrangement includes a retaining clip (15) having a U-shaped cross-section, and a free-state diameter which is less than a diameter of the retaining clip (15) when assembled to retain vehicle drive wheel hub (2) to a constant velocity joint (3). The retaining clip (15) is retained within an open axial bore of the constant velocity joint (3), axially inboard of a set of inward splines (12), which are configured to engage a matching set of outward splines (8) associated with a coupling ring (14) secured to the vehicle drive wheel hub (2). The retaining clip (15) leading edge is configured to engage a retaining groove (G) in the coupling ring (14), thereby coupling the constant velocity joint (3) to the vehicle drive wheel hub (2).

Description

DRIVING WHEEL ASSEMBLY

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to and claims priority from U.S. Provisional Patent Application No. 60/799,131 filed on May 10, 2006, which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

This invention relates in general to a coupling arrangement for transferring drive torque between a constant velocity joint and a vehicle drive wheel hub, and more particularly to a coupling arrangement which utilizes an expanding annular retaining ring to removably couple a constant velocity joint to a vehicle drive wheel hub.

The conventional arrangement to transfer drive torque to a drive wheel from a drive shaft through a constant velocity joint is for the constant velocity joint to have a solid splined shaft extending axially outward from the constant velocity joint which is configured to engage a splined member within the wheel hub. With a solid splined shaft, there is a substantial amount of material close to the rotational axis having a small radius of gyration. As such, there is substantially more weight in the combined assembly than is necessary when utilizing such a conventional coupling. Alternative connections, which seek to eliminate material near the axis of rotation, have been attempted, but have been shown to have deficiencies in serviceability, bearing clamping, and/or sealing of the connection.

Accordingly, it would be advantageous to provide a coupling arrangement for transferring drive torque between a constant velocity joint and a vehicle drive wheel hub which does not require the use of a solid splined shaft. It would be further advantageous to provide such a coupling which provides a secure coupling between the constant velocity joint and the vehiclθ drive wheel hub, maintains an adequate seal against contaminants, and which may be readily disassembled during service procedures.

BRIEF SUMMARY OF THE INVENTION

Briefly stated, an embodiment of the present disclosure provides a coupling arrangement for transferring drive torque between a constant velocity joint and a vehicle drive wheel hub. The coupling arrangement includes a retaining clip having a U-shaped cross-section, a discontinuous or split outer diameter, and a free-state diameter which is less than a diameter of the retaining clip when assembled to retain vehicle drive wheel hub to a constant velocity joint. The retaining clip is retained within an open axial bore of the constant velocity joint, axially inboard of a set of inward splines, which are configured to engage a matching set of outward splines associated with a coupling ring secured to the vehicle drive wheel hub. As the constant velocity joint and the vehicle drive wheel hub are pressed into engagement at the splines, the retaining clip leading edge slides along an expanding surface of the coupling ring, expanding the outer diameter of the ring to fit over and engage with a retaining groove in the coupling ring, thereby coupling the constant velocity joint to the vehicle drive wheel hub. The retaining clip includes a set of tabs or ears adjacent a split or break in the outer diameter, which are configured to receive an associated expanding tool, facilitating expansion of the retaining clip outer diameter for release from the retaining groove to enable removable of the vehicle drive wheel hub from the constant velocity joint during servicing or replacement.

The foregoing and other objects, features, and advantages of the invention as well as presently preferred embodiments thereof will become more apparent from the reading of the following description in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a sectional view of a portion of a vehicle drive wheel hub and constant velocity joint assembly coupled together according to the present disclosure;

Figure 2 is an isometric view of the constant velocity joint retaining clip of the present disclosure;

Figure 3 is a axial view into the hub bore of an assembled showing the "ears" of the constant velocity joint retaining clip;

Figure 4 is an alternative embodiment of a portion of a vehicle drive wheel hub and constant velocity joint coupled together according to the present disclosure wherein the hub assembly is detachable from the supporting suspension knuckle;

Figure 5 is a sectional view of the constant velocity joint retaining clip of Fig. 2, in the Z-plane; and

Figure 6 is an enlarged portion of Figure 1 , illustrating the retaining clip engagement between the hub and constant velocity joint.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to Figure 1 , a vehicle wheel drive hub assembly includes suspension knuckle 1 and a rotatable hub 2. The rotatable hub 2 includes a wheel mounting face 4, wheel pilot surface 5, wheel retention features, bearing inner race surfaces 7 for rolling elements 10, and an external spline 8 which is capable of receiving driving torque. The suspension knuckle supports bearing outer race surfaces 6 which function cooperatively with the inner race surfaces 7 and rolling elements 10 to support the rotatable hub 2 for driven rotation about an axis X. - A -

As shown in Figure 1 , two rows of rolling elements 10 separate the inner races 7 from the outer races 6, and are circumferentially and rotationally spaced by cages (not shown) as is conventional in the art. The bearing outer races 6 may be press fitted into an axial bore in the suspension knuckle 1 , and axially located by a snap ring 1 1 . Those of ordinary skill in the art will recognize that a variety of configurations and assembly methods for the inner races 7, outer races 6, and rolling elements 10 may be utilized without departing from the scope of the present disclosure. For example, in the embodiment shown in Figure 1 , the hub assembly comprises one integral bearing inner race 7 and one initially separate inner race 13. During assembly, these components are measured, and an assembled bearing preload is predicted and dimensionally adjusted by grinding the locating surface (small end) of the inner race 13 prior to pressing it onto the hub 2. Alternative methods of attaching the bearing outer races to the knuckle are well known in the prior art. One such method is shown in figure 4 where a double outer race 21 , is attached to the knuckle by cap screws 22.

Driving torque is provided to the vehicle wheel drive hub assembly through the external spline 8 from a matching internal spline 12 extending radially inward from an inner surface of an axial bore on the driving member. As shown in Figure 1 , the driving member is a constant velocity joint 3, but is not limited to such. The external spline 8 may be integrally formed into the rotatable hub 2, or may consist of a spline ring coupler 14 engaged with the rotatable hub 2, and axially trapped between the inner race 7 and a formed abutment shoulder on the rotatable hub 2, such as shown and described in U.S. Patent No. 6,299,360 and U.S. Patent No. 6,443,622 both of which are incorporated herein by reference.

The driving member or constant velocity joint 3 is coupled to, and prevented from separating from, the vehicle wheel drive hub assembly by a retaining clip 15 which is axially trapped loosely within an axial bore of the constant velocity joint 3 between an inside shoulder of the internal splines 12 and a grease dam 17. Referring to Figures 2 and 5, the retaining clip 15 has a U-shaped cross section, and has a discontinuous outer diameter which is broken by an expansion break 25.

In a free state, the ends of the retaining clip 15 at the expansion break

25 are spaced apart, such that the outer diameter of the retaining clip 15 is greater than the inner diameter of the internal splines 12 of the constant velocity joint 3, but less than the inner diameter of the axial bore of the constant velocity joint. An inner diameter of at least one branch of the U- shaped retaining clip is less than the inner diameter of the internal splines 12, such that at portion of the retaining clip 15 extends radially inward past the internal splines 12. Movement of the retaining clip 15 through the axial bore of the constant velocity joint 3 is prevented by abutment with the internal splines 12.

The outer diameter of the retaining clip 15 may be reduced to a size smaller than the inner diameter of the internal splines 12 by compressing the ends of the retaining clip together, closing the expansion break 25, and thereby enabling the retaining clip 15 to be withdrawn from the axial bore of the constant velocity joint 3 past the internal splines 12.

Conversely, by expanding the distance between the ends of the retaining clip, the size of the expansion break, and correspondingly, the outer diameter of the retaining clip 15 may be expanded to a maximum diameter which is limited by the inner diameter of the axial bore of the constant velocity joint 3 within which is it loosely fitted.

To facilitate expansion and contraction of the outer diameter of the retaining clip 15 by opening or closing the spacing between the ends at the expansion break 25, a pair of radially inward tabs or "ears" 16 are formed into one side of the U-shaped cross section, adjacent the expansion break 25. Preferably, the tabs 16 extend radially inward into the axial bore of the constant velocity joint 3 as shown in Figure 3, and include suitable means to be engaged by tools to effect the expansion or contraction of the retaining clip 15 during assembly or removal of the constant velocity joint 3.

During coupling of the vehicle wheel drive hub assembly 2 to the constant velocity joint 3 on the longitudinal axis X, the hub 2 and constant velocity joint 3 are axially pressed into engagement at the external and internal splines. As can be seen in Figure 6, the hub 2 and constant velocity joint 3 are axially pressed into engagement until the leading edge of the internal splines 12 abuts against the outer end of the inner race 13, at which point the external and internal splines are fully engaged. As the spines are axially brought into engagement, the leading edge of the U-shaped retaining clip 15 encounters a conical expansion surface 9 on the leading edge of the spline ring coupler 14 or formed surfaces of the hub 2. The expansion surface 9 forces the retaining clip 15 to expand radially outward, increasing the outer diameter of the retaining clip 15 as the hub 2 and constant velocity joint 3 are axially pressed into engagement. As the external and internal splines fully engage, the expanded retaining clip is pressed passed the outermost diameter of the expansion surface 9, relaxing into, and engaging with a retaining groove G. The retaining clip 15 is trapped between the shoulder of the internal splines 12 of the constant velocity joint 3 and the retaining groove G on the hub 2, hence preventing the hub 2 and constant velocity joint 3 from separating along the axis X.

After assembly, as seen in Figure 3, the tabs or ears 16, of the retaining clip 15 extend into the axial bore of the assembled hub 2 and constant velocity joint 3. To disassembly the hub 2 from the constant velocity joint 3, the tabs 16 may be engaged with a tool and separated, expanding the outer diameter of the retaining clip 15 within the axial bore, such that the leading edge of the retaining clip 15 disengages from the retaining groove G. With the retaining clip 15 maintained in the enlarged diameter configuration, the hub 2 and constant velocity joint 3 may be axially separated for servicing or repair.

Upon assembly, those of ordinary skill in the art will recognize that a variety of seals may be provided to protect the interface between rotating and non-rotating components of the hub 2 and the constant velocity joint 3. For example, as can be seen in Figures 1 and 4, on the constant velocity joint side at least one seal lip 19 may be provided to contact the inner ring and a second seal lip 20 may be provided to contact the constant velocity joint 3. This protects the interface between the constant velocity joint 3 and the rotating hub 2 from corrosion. Also, the seal lip 20 contact diameter on the constant velocity joint 3 is greater than the contact diameter on the inner ring so that when water breaches the constant velocity joint lip 20, it flows radially outward by gravity or centrifugal force to challenge the constant velocity joint lip 20 and escape before challenging the seal lip 19 at the inner race.

A sealing plug 18 may be disposed in the axial bore of the rotatable hub 2 to protect the internal interfaces of the constant velocity joint 3 and rotatable hub 2 from corrosion.

Although not shown, a sensor may protrude through the knuckle to sense the rotation of the rotatable hub 2. It may also protrude through or be combined with the seal 20 at the constant velocity joint side of the knuckle.

Claims

CLAIMS:

1. A vehicle driving wheel hub assembly comprising a knuckle, a hub, a drive member, and a retaining clip, said hub including external splines for receiving driving torque from the drive member, a retaining groove located axially inboard from the external splines, said drive member including internal splines for engaging the external splines of the hub; and wherein the retaining clip is retained within an axial bore of the drive member axially inboard from the internal splines, the retaining clip configured to engage the retaining groove to secure said drive member to said hub; and wherein the retaining clip is expandable for release from the retaining groove to enable separation of driving member from the hub.

2. An arrangement according to Claim 1 wherein said retaining clip is expandable by a tool engaged with an inner periphery of said retaining clip.

3. An arrangement according to Claim 2 where said retaining clip has a generally U-shaped cross-section.

4. An arrangement according to Claim 1 further comprising a non-rotating seal having first and second seal lips, said first seal lip contacting a bearing inner race on the hub, said second seal lip contacting the drive member, the contacting diameter of said first lip being smaller than the contacting diameter of the second seal lip.

5. An arrangement according to Claim 1 further including an expanding surface adjacent the retaining groove,.

6. An arrangement according to Claim 5 wherein said expanding surface defines an outwardly expanding conical surface configured to engage a peripheral edge of said retaining clip to expand an outer diameter of the retaining clip during axial coupling of the hub to the drive member, wherein said retaining clip engages said retaining groove.