Unitized wheel end assembly

Abstract

A wheel-end assembly includes a wheel hub capable of being connected to a wheel and having a wheel hub bore for accommodating an axle. An inboard bearing located in the wheel hub bore includes an outer ring connected to the wheel hub, an inner ring located within the outer ring, and rolling elements. A sealing unit is connected to the inner ring of the bearing to maintain the inner ring within the outer ring when the wheel-end assembly is separated from the axle. An outboard bearing located in the wheel hub bore includes an outer ring connected to the wheel hub, an inner ring located within the outer ring, and rolling elements. A nut unit is arranged to be positioned adjacent to the outboard bearing and includes a nut capable of being engaged with the axle via threads. A retaining member holds the nut unit near the outboard bearing to limit axial displacement of the inner ring of the outboard bearing, thereby maintaining the inner ring within the outer ring when the wheel end is separated from the axle.

Description

Technical Field

[0001] The present invention relates to bearings, and more particularly to wheel end assemblies including bearings. Background Art

[0002] Wheel-end assemblies, particularly those used in truck axles, typically include a hub capable of connecting to a wheel and two bearings disposed within the hub for assembly on a stationary axle, such as a spindle tube. Seals are commonly found within oil-lubricated truck axles and wheel-ends, primarily to retain lubricant within the axle and prevent leakage. These seals typically engage a sleeve mounted on the stationary axle and have the secondary function of preventing contaminants from entering the bearings.

[0003] Furthermore, in this type of wheel end, the outboard bearing is fastened to the spindle tube via a nut assembly, thereby securing the wheel end to the spindle tube. Typically, the wheel hub, two sets of bearings, seals, and the nut assembly are provided as separate components, with the two sets of bearings being provided as four discrete parts: an inboard bearing cup, an inboard bearing cone, an outboard bearing cup, and an outboard bearing cone. These separate parts must be assembled one by one by the customer, such as the vehicle manufacturer. Summary of the Invention

[0004] In one aspect, the present invention is a wheel-end assembly for rotatably connecting a wheel to an axle. The wheel-end assembly includes a generally cylindrical hub capable of being connected to a wheel, the hub having an inboard axial end, an outboard axial end, and an inner circumferential surface defining a hub bore. An inboard bearing is disposed in the hub bore and includes an outer ring coupled to the hub, an inner ring positioned within the outer ring and capable of being positioned about an axle, and a plurality of rolling elements disposed between the inner and outer rings. A seal assembly is coupled to the inner ring of the inboard bearing and is configured to maintain the inner ring at least partially within the outer ring when the wheel-end assembly is separated from the axle. By coupling the seal to the bearing, the precise placement of the seal on the bearing prevents damage to the seal that often occurs when the hub is "blindly" installed on the axle during assembly, as is the case with prior art wheel-end assemblies. In addition, the outboard bearing is arranged in the wheel hub hole, and forms a gap with the inboard bearing in the axial direction from the outboard end side of the wheel hub. The outboard bearing includes an outer ring connected to the wheel hub, an inner ring located inside the outer ring and capable of being arranged around the axle, and a plurality of rolling elements arranged between the inner and outer rings. In addition, the nut unit is arranged to be located close to the outboard bearing, including a nut configured to be threadably engaged ( / engaged by thread / screwed) with a portion of the outer surface of the axle, so as to connect the wheel end assembly to the axle. The retainer is configured to keep the nut unit axially located near the outboard bearing, so that the nut unit limits the axial displacement of the inner ring of the outboard bearing to keep the inner ring of the outboard bearing at least partially located within its outer ring when the wheel end assembly is separated from the axle.

[0005] On the other hand, the present invention is also a wheel-end assembly for rotatably connecting a wheel to an axle. The wheel-end assembly includes a generally cylindrical hub that can be connected to a wheel, the hub having an axial end on the inner side of the cabin, an axial end on the outer side of the cabin, and an inner circumferential surface that defines a hub hole. The bearing is disposed in the hub hole and includes an outer ring connected to the hub, an inner ring located inside the outer ring and capable of being disposed around the axle, and a plurality of rolling elements disposed between the inner and outer rings. A sealing unit is provided for sealing the annular space between the inner and outer rings of the bearing, and the sealing unit is configured to keep the inner ring at least partially located within the outer ring when the wheel-end assembly is separated from the axle.

[0006] On the other hand, the present invention is still a wheel end assembly for connecting a wheel to an axle in a rotatable manner. The wheel end assembly includes a generally cylindrical hub that can be connected to a wheel, the hub having an axial end on the inner side of the cabin, an axial end on the outer side of the cabin, and an inner circumferential surface that defines a hub hole. The bearing is arranged in the hub hole, and includes an outer ring connected to the hub, an inner ring located inside the outer ring and capable of being arranged around the axle, and a plurality of rolling bodies located between the inner and outer rings. The nut unit is arranged to be located close to the bearing, and includes a nut and a washer: the nut is constructed to connect the wheel end assembly to the axle by threaded engagement with the outer surface portion of the axle, and the washer is arranged to be at least partially located between the nut and the inner ring of the bearing, and the nut is movably connected to the washer. The retaining member is connected to the wheel hub and can be contacted by the washer to keep the nut unit axially located near the bearing, so that the nut unit limits the axial displacement of the inner ring of the bearing, and keeps the inner ring of the bearing at least partially located within the outer ring of the bearing when the wheel end assembly is separated from the axle.

[0007] In still another aspect, the present invention is a method of assembling a wheel end assembly on an axle having a central axis, a free end, and an outer circumferential surface having a threaded portion formed thereon. The method includes the following steps: providing a wheel end assembly including a hub, the hub having an inboard end, an outboard end and a hub bore; an inboard bearing disposed in the hub bore, having an inner ring and an outer ring connected to the hub; a seal configured to maintain the inner ring of the inboard bearing within the outer ring of the inboard bearing; an outboard bearing disposed in the hub bore, having an inner ring and an outer ring connected to the hub; a nut unit disposed in a position proximate to the outboard bearing, having a nut capable of threadedly engaging ( / threadedly engaging) with an axle; a retainer configured to maintain the nut unit proximate to the outboard bearing so as to maintain the inner ring of the outboard bearing within the outer ring of the outboard bearing; inserting the free end of the axle into the inboard end of the hub; moving the wheel end assembly in an axial direction ( / central axis of the axle) until the axle extends through the inboard bearing, the outboard bearing and the nut unit; and rotating the nut about a threaded portion on an outer surface of the axle to connect the wheel end assembly to the axle. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The above summary of the present invention and the detailed description of the preferred embodiments will be better understood by reading them in conjunction with the accompanying drawings. For the purpose of illustrating the present invention, the schematic diagrams show exemplary embodiments that are currently considered to be more desirable. However, it should be understood that the present invention is not limited to the specific structures and means shown in the drawings. In the following drawings:

[0009] Figure 1is an axial cross-sectional view of a wheel end assembly according to the present invention;

[0010] Figure 2 yes Figure 1 A partial magnified view of the upper middle area;

[0011] Figure 3 yes Figure 1 a greater degree of detail of a portion of the tank showing the inboard bearing and seal unit;

[0012] Figure 4 yes Figure 3 A partial enlarged view showing the sealing unit;

[0013] Figure 5 is an enlarged view of the sealing unit showing a candidate structure without a sealing cover member;

[0014] Figure 6 yes Figure 1 a greater degree of detail of a portion of the pod showing the outboard bearing and retaining members;

[0015] Figure 7 yes Figure 6 A partial enlarged view showing the retaining member and the nut unit; and

[0016] Figures 8A to 8D Together they form Figure 8, which depicts certain steps in the process of assembling the wheel end assembly to the axle. DETAILED DESCRIPTION

[0017] In the following description, certain terms are used for convenience only and are not intended to be limiting. The words "inward," "inwardly," and "outwardly" refer to directions toward or away from a designated centerline or geometric center of the components being described, respectively, and their specific meanings will be apparent from the context. Furthermore, as used herein, the words "connected" and "connected" are intended to encompass both a direct connection between two components without any intervening components and an indirect connection between two components with one or more intervening components. This terminology includes the above-mentioned specific words, their derivatives, and words of similar meaning.

[0018] Reference is now made in detail to the drawings, wherein like reference numerals are used to refer to like parts throughout. Figure 1 Figures 1 to 8 show a wheel end assembly 10 for rotatably coupling a wheel (not shown) to an axle ( / axle) 1 of a vehicle (preferably a medium-duty truck, not shown) (see Figure 8). The outer surface 2 of the axle 1 has a threaded portion 2a. The axle 1 is preferably a non-rotatable or "fixed" vehicle spindle tube. The wheel can rotate about a central axis A extending through the axle or spindle tube 1. CThe wheel-end assembly 10 basically includes a hub 12 capable of being connected to a wheel, an inboard bearing 14, a sealing unit 16 for sealing the inboard bearing 14, an outboard bearing 18, a locking nut unit 20 for retaining the outboard bearing 18 on the axle 1, and a retainer 22 for retaining the nut unit 20. More specifically, the hub 12 is generally cylindrical or tubular in shape, having an inboard axial end 12a, an outboard axial end 12b, an inner circumferential surface 13A defining a (hub) hole 15, and an outer circumferential surface 13B opposite to the inner circumferential surface 13A. In addition, the inboard bearing 14 is disposed in the hub hole 15 and includes an outer ring 30 coupled to the hub 12, an inner ring 32 located inside the outer ring 30 and capable of being disposed around the axle 1, and a plurality of rolling elements 34 disposed between the inner ring 32 and the outer ring 30. The sealing unit 16 is provided to seal the annular space SA between the outer ring 30 and the inner ring 32 of the bearing (see FIG. Figure 1 ), and is configured to keep the inner race 32 at least partially located within the outer race 30 when the wheel-end assembly 10 is separated from the axle 1. Specifically, the sealing unit 16 is coupled to the bearing inner race 32 and is configured to seal radially outward against the inner surface 13A of the wheel hub, or (preferably) to seal against the inner circumferential surface 65B of a sealing member 64 coupled to the wheel hub 15, as described below, to avoid the need to seal the axle 1 for reasons discussed below.

[0019] Furthermore, an outboard bearing 18 is also disposed within the wheel hub bore 15 and is axially spaced from the inboard bearing 14 on the outboard end 12b side of the wheel hub. Outboard bearing 18 includes an outer ring 40 connected to the wheel hub 12, an inner ring 42 positioned within outer ring 40 and capable of being disposed around the axle 1, and a plurality of rolling elements 44 disposed between outer ring 40 and inner ring 42. Furthermore, a nut unit 20 is disposed proximate to the outboard bearing 18 and includes a lock nut 21 configured to threadably engage the outer surface portion 2a of the axle 1 (see FIG. 8 ), thereby coupling the wheel-end assembly 10 to the axle 1. A retainer 22 is configured to maintain the nut unit 20 axially proximate to the outboard bearing 18, thereby restricting axial displacement of the inner ring 42 of the outboard bearing. In this manner, when the wheel-end assembly 10 is separated from the axle 1, the retainer 22 maintains the inner ring 42 at least partially within the outer ring 40 of the outboard bearing.

[0020] Thus, by providing the seal unit 16 for retaining the inner race 32 of the inboard bearing within the outer race 30, and the retaining member 22 for retaining the nut unit 20, thereby retaining the inner race 42 of the outboard bearing within the outer race 40, the wheel end assembly 10 of the present invention provides a "unitary" wheel end. That is, all components required for the wheel end 10 can be pre-assembled within the wheel hub 12 and shipped to the customer (e.g., an original equipment manufacturer (OEM)) in a state ready for direct assembly to the axle 1, as discussed in detail below. Furthermore, because the bearings 14 and 18 are preferably angular contact bearings, arranged with the cups facing outward, as discussed below, their ability to retain the inner races 32 and 42 "in place" during shipping is particularly advantageous.

[0021] Furthermore, by assembling the inboard seal unit 16 on the bearing 14 and sealing radially outward, as opposed to conventional devices that seal radially inwardly on the axle's outer surface 2, the seal 16 is fully supported and precisely assembled before the wheel-end assembly 10 is assembled onto the axle 1. In this way, potential hazards caused by impacts with the axle 1, such as might occur if the axle 1 were to pass through the inner circumference of an "unsupported," inwardly sealing conventional seal unit, are eliminated. These and other aspects of the present invention will be described in greater detail below through a discussion of the basic components and structures described above.

[0022] See also Figure 1 and 2 The wheel hub 12 preferably has an annular flange 24 in the middle, which extends radially outward from the outer surface 13B and can be connected to the wheel by a plurality of bolts 25 ( Figure 1 In this way, the hub 12 and the bearing outer rings 30 and 40 connected to the hub 12 can be rotated around the central axis A. C Rotation. Preferably, the hub 12 includes two annular shoulders 26 and 27, each extending radially inward from the inner surface 13A of the hub and spaced apart in the axial direction. Each shoulder 26, 27 positions and axially retains an independent bearing outer ring 30, 40, respectively. In addition, an annular groove 28 extends radially outward from the inner surface 13A of the hub and is configured to accommodate a preferred retaining member 22, as described below. In addition, the outboard end 12b of the hub 12 preferably has a plurality of mounting holes 29 for connecting the flange 6 of the drive shaft 5 to the hub 12 (see FIG. Figure 8D ), as described below.

[0023] Now see Figures 1 to 3Inboard bearing 14 is preferably formed as a tapered roller bearing, wherein outer ring 30 is formed as a "cup" to provide a tapered outer ring raceway 33, inner ring 32 is formed as a "cone" to provide a tapered inner ring roller 36, and rolling elements 34 are tapered rollers, each capable of rolling on both rollers 33 and 36. Specifically, outer ring 30 has a cylindrical outer circumferential surface 31B and an angled inner circumferential surface portion 31A that provides bearing outer ring raceway 33. Outer ring outer surface 31B is preferably frictionally engaged with inner surface 13A of hub 12 (e.g., by press-fitting), positioning outer ring 30 against inboard hub shoulder 26 to assemble outer ring 30 to hub 12. Preferably, the outer ring 30 is arranged relative to the hub 12 in such a way that its angled inner circumferential surface 31A and thus also angled outer ring raceway 33 are generally oriented toward the inboard axial end 12a of the hub.

[0024] Furthermore, the bearing inner ring 32 has an angled outer circumferential surface portion 35A and a cylindrical inner circumferential surface 35B. The outer circumferential surface 35A provides the inner ring raceway 36 of the bearing, and the inner circumferential surface 35B is dimensioned to engage with the outer surface 2 of the axle in a frictional engagement manner for mounting the inner ring 32 on the axle 1. Inner ring 32 preferably has an annular groove 37 (see FIG. Figure 3 An annular sealing member 66 (e.g., an O-ring) is disposed in groove 37, extending radially inward from inner surface 35B of the inner ring near its inboard end 32a. When the wheel-end assembly 10 is assembled on the axle 1, the annular sealing member 66 seals against the outer surface 2 of the axle 1, preventing fluid (e.g., oil) from leaking between the inner ring 32 and the axle 1. Furthermore, the inner ring 32 preferably includes an annular shoulder 39 extending axially from the angled main body 38 that provides the inner ring raceway 36. The shoulder 39 has a cylindrical outer surface 39a. The inner ring 32 is positioned within the wheel hub 12 such that its angled outer surface portion 35A (and the inner ring raceway 36) face generally away from the inboard axial end 12a of the hub.

[0025] With this type and arrangement of inboard bearing 14, whenever the inboard end 12a of the hub tilts downward relative to the outboard end 12b, the bearing inner race 32 could shift axially toward the inboard end 12a of the hub without being blocked by the current seal unit 16. This displacement of the inner race 32 could potentially lead to separation between the inner race 32 and the rolling elements 34, and the outer race 30 subsequently falling outward from the inboard end 12a of the hub. However, because the seal unit 16 (in addition to its sealing function) provides a secondary function of retaining the bearing inner race 32 within the outer race 30, as described in more detail below, these potential adverse consequences are eliminated.

[0026] See also Figures 1 to 5 The sealing unit 16 is axially located between the bearing outer ring 30 and the inner end 12a of the hub, preferably connected to the bearing inner ring 32, and connected to the hub 12 (see Figure 5 ) or a sealing member 64 connected to the hub 12 (see Figures 1 to 4 ) sealingly engageable. This sealing engagement is sufficient to prevent axial displacement of the inner race 32 when the wheel-end assembly 10 is separated from the axle 1. Alternatively, the sealing unit 16 may be connected to the wheel hub 12, thereby sealingly engaging the inner race 32 to prevent any displacement of the inner race (this structure is not shown). In either case, the sealing unit 16 provides sufficient frictional engagement with the seal 50, as described below, to maintain the bearing inner race 32 in a specific axial position (i.e., inside the outer race 30).

[0027] See also Figures 3-5 The sealing unit 16 preferably includes an annular seal 50 disposed around the outer surface 39a of the inner ring shoulder 39 and having an outer circumferential sealing lip 52. In this manner, the seal 50 is positioned relative to the central axis A. C The inner circumferential surface 65B of the sealing member 64 is non-rotatable or fixedly disposed, sealing radially outward against rotation, as described below. The seal 50 preferably includes an annular, rigid base component 54 coupled to the inner race 32 and an annular, elastomeric sealing component 56 coupled to the base component 54 to provide the sealing lip 52. More specifically, the base component 54 has an axial portion 58 disposed about the shoulder 39 of the bearing inner race 32 and a radial portion 59 extending outward from the axial portion 58, thereby giving the base component 54 a generally L-shaped axial cross-section. The axial portion 58 of the base component 54 has an inner circumferential surface 58a, which is preferably provided with an elastomeric layer 61 for sealing between the seal 50 and the inner race shoulder 39.

[0028] In addition, the sealing assembly 56 further includes a main cantilever portion 60 extending generally axially from the radial portion 59 of the base assembly 54 and having an outer circumferential wedge portion 62 for providing the sealing lip 52. The sealing assembly 56 also preferably includes an outer circumferential second sealing lip 53 axially spaced from the first sealing lip 52. In a preferred embodiment, the sealing unit 16 further includes an annular biasing member ( / biasing member / pressure member) 63, preferably a garter spring, which is configured to press ( / bias) the cantilever portion 60 of the elastomeric sealing assembly 56 radially outward to maintain sufficient sealing pressure at the primary sealing interface SI (see Figure 4 ).

[0029] Now see Figure 3 and 4 Seal unit 16 preferably further includes an annular cover member 64 that at least partially surrounds and encloses seal 50. Cover member 64 has an outer circumferential surface 65A and an inner circumferential surface 65B opposite outer circumferential surface 65A. Outer circumferential surface 65A frictionally engages inner surface 13A of the hub, allowing cover member 64 to be assembled onto hub 12. Sealing lip 52 sealingly engages inner surface 65B of cover member 65, thereby eliminating the need for machined surfaces for sealing engagement. Cover member 64 preferably has a generally L-shaped axial cross-section, including an axial portion 65 providing inner and outer circumferential surfaces 65A and 65B, and a radial portion 67 extending inwardly from axial portion 65. Radial portion 67 of cover member is axially spaced from outer ring 30 of the inboard bearing, such that seal 50 is axially disposed between outer ring 30 and radial portion 67 of cover member. Furthermore, the elastomeric component 56 of the seal 50 preferably further includes a sealing lip 68 extending generally axially, which can be engaged with the radial portion 67 of the cover member in a sealing manner, thereby reducing the amount of contaminants (especially solid particles) reaching the main sealing interface SI.

[0030] Therefore, the seal unit 16 described above is preferably formed as a "box-type" seal with all of its components enclosed within the inner and outer members (in this case, between the shoulder 39 of the bearing race and the wheel hub 12) so that it can be installed integrally. This eliminates the need for the end user to machine the outer surface 2 of the axle to provide a smooth, continuous running surface for the inboard seal. However, the seal unit 16 can also be configured without the cover member 64. In this case, the sealing lip 52 seals directly against the inner surface 13A of the wheel hub, or even against the outer surface 39a of the shoulder (i.e., using a base member of appropriate form connected to the wheel hub 12). The scope of the present invention includes various variations of the seal unit 16 that can retain the inner race 32 of the inboard bearing within the outer race 30 of the bearing when the wheel-end assembly 10 is separated from the axle 1.

[0031] Now see Figure 1 、 2 As with inboard bearing 14, outboard bearing 18 is preferably formed as a tapered roller bearing. The outer ring 40 is formed as a cup, providing a conical outer ring raceway 43; the inner ring 42 is formed as a cone, providing a conical inner ring raceway 46; and the rolling elements 44 are tapered rollers, each rolling on both raceways 43 and 46. Specifically, outer ring 40 has an angled inner circumferential surface portion 41A, which provides the bearing's outer ring raceway 43, and a cylindrical outer circumferential surface 41B. Outer ring outer surface 41B is preferably frictionally engaged with inner surface 13A of hub 12 (e.g., press-fit). Outer ring 40 is assembled to hub 12 by seating it against outboard hub shoulder 27. Preferably, the outer ring 40 is arranged relative to the hub 12 such that its angled inner circumferential surface 41A, and thus its angled outer ring raceway 43, is generally oriented toward the outboard axial end 12b of the hub.

[0032] Furthermore, the bearing inner ring 42 has an angled outer circumferential surface portion 45A which provides the inner ring raceway 46 of the bearing and a cylindrical inner circumferential surface 45B which is sized to frictionally engage the outer surface 2 of the axle to mount the inner ring 42 on the axle 1 (see FIG. Figure 8A). The inner race 42 is arranged in the hub 12 so that its angled outer surface portion 45A (and the inner race raceway 46) are generally oriented in the opposite direction of (or away from) the hub bay outboard end 12b. For the same reasons as the inboard bearing 14, in the absence of the retainer 22, when the wheel end assembly 10 is in an unassembled state and the hub bay outboard end 12b is tilted downward relative to the inboard end 12a, the structure and arrangement of the outboard bearing 18 in the preferred case allows the inner race 42 to be displaced axially outward from the interior of the outer race 40. However, such displacement is blocked by the nut unit 20 and the retainer 22, as described below.

[0033] Now see Figure 6 and 7 The nut unit 20 is positioned axially adjacent to the outboard bearing 18, positioned between the bearing 18 and the outboard end 12b of the hub. In addition to the lock nut 21, it also includes a washer 70 and a keeper 72, as described below. The nut 21 includes a generally cylindrical body 74 having an inner circumferential surface 75, an outer circumferential surface 76 opposite the inner circumferential surface 75, and an annular groove 77 with a threaded portion 75a formed thereon. The annular groove 77 extends radially inward from the outer circumferential surface 76 and is partially defined by opposing radial surfaces 79A and 79B. The washer 70 is at least partially positioned between the nut 21 and the bearing inner ring 42, enabling it to be clamped therebetween. The nut 21 is movably coupled to the washer 70 (preferably via the keeper 72, as discussed below), enabling the nut 21 to be displaced axially relative to the washer 70. More specifically, the washer 70 includes an annular body 78 having a generally L-shaped cross-section, the body 78 having an outer axial portion 82 and an inner radial portion 80 axially interposed between the nut 21 and the bearing inner race 42. The axial portion 82 of the washer has a first end 82a integrally formed with the radial portion 80 and a free second end 82b opposite the first end 82a and capable of engaging with the retainer 22. As described below, the second end 82b extends axially in a direction away from the outboard bearing 18. In addition, the radial portion 80 of the washer 70 preferably includes a radially inwardly extending tab (not shown) that can be disposed in an axially extending groove (not shown) in the outer surface 2 of the axle to prevent the washer 70 from rotating about the central axis A. C Rotate.

[0034] Furthermore, the keeper 72 includes a generally annular body 84 having an outer axial portion 86 connected to the washer 70 and an inner radial portion 88 at least partially disposed in the nut groove 77 for coupling the washer 70 to the nut 21. Specifically, the axial portion 86 of the keeper is configured to be smaller in diameter than the axial portion 82 of the washer, and has its outer circumferential surface 87 frictionally engaged with the inner circumferential surface 83 of the axial portion 82 of the washer. Furthermore, the nut groove 77 is sized such that the axial dimension (not labeled) between its facing radial surfaces 79A and 79B is substantially greater than the axial thickness t of the keeper radial portion 88. A (See Figure 7 ), so that the nut 21 can be removably coupled to the washer 70. In this manner, to assemble the nut unit 20 on the axle 1, the washer 70 is juxtaposed with the outboard end 42a of the outboard bearing inner ring 42, and then the nut 21 is screwed around the threaded portion 2a of the axle outer surface 2 until the inboard end 72a of the nut body grips the radial portion 80 of the washer.

[0035] Still see Figure 6 and 7 Retainer 22 is axially positioned between outboard bearing 18 and outboard end 12b of the hub, accessible by washer 70 to limit axial movement of washer 70 and, consequently, nut 21. More specifically, retainer 22 preferably comprises an annular disk 90, most preferably generally formed as a conventional C-clip, having an inner radial end 92A, an outer radial end 92B, and a radial stop surface 94. Outer radial end 92B is disposed within annular groove 28 of the hub to attach retainer 22 to hub 12; inner radial end 92A is radially spaced apart from nut 21. Furthermore, retainer 22 is positioned such that its radial stop surface 94 is accessible by washer 70, specifically, by free end 82b of washer axial portion 82. This contact between the washer end 82 b and the retainer surface 94 causes the washer radial portion 80 to substantially prevent axial displacement of the outboard bearing inner race 42 , thereby maintaining the inner race 42 at least partially within the outer race 40 .

[0036] See also Figures 8A to 8DThe wheel-end assembly 10 of the present invention enables an integrated wheel-end to be provided to customers for simple assembly on the axle 1 of a vehicle. That is, by providing an integrated wheel-end assembly 10 (including an inboard bearing 14, an outboard bearing 18, and a nut unit 20 held by a retainer 22, which are retained by a pre-assembled sealing unit 16), the wheel-end assembly 10 can be assembled by the following steps: inserting the axle or shaft tube 1 into the wheel-end assembly 10; tightening ( / rotating) the nut 21 to fasten the wheel-end assembly 10 to the axle 1; inserting the drive shaft 5 (commonly known as a "half shaft") through the outboard end 12b of the wheel hub 12 and into the shaft hole 3 of the axle or shaft tube 1; and then attaching the flange 6 of the drive shaft 5 to the outboard end 12b of the wheel hub 12.

[0037] More specifically, the provided wheel end assembly 10 is positioned close to the axle 1 and then moved toward the axle 1 so that the free end 1a of the axle 1 is inserted into the inner end 12a of the wheel hub 12. The wheel end assembly 10 is positioned along the central axis A of the axle. C Shift until the axle 1 passes through the inboard bearing 14, the outboard bearing 18 and the nut unit 20. Next, screw the locking nut 21 around the threaded portion 2a of the axle outer surface 2 to connect the wheel end assembly 10 to the axle 1. Preferably, the nut 21 is tightened against the washer 70 to establish a desired preload or end-play with the outboard bearing 18. Then, the free end (first end) 5a of the drive shaft 5 is inserted into the outboard end 12b of the wheel hub, through the free end 1a of the axle 1 and into the shaft hole 3. Thread the drive shaft 5 along the central axis A of the axle. C The nut 21 is then displaced until the flange 6 of the drive shaft 5 abuts the outboard end 12b of the wheel hub. Finally, the drive shaft flange 6 is connected to the outboard end 12b of the wheel hub to fully secure the wheel end assembly 10 to the axle 1. When it is desired to maintain or replace the wheel end assembly 10, the nut 21 can be loosened from the axle 1 and then retained by the retainer 22, so that the wheel end assembly 10 can then be pulled ( / extracted) from the axle 1 as a complete unit.

[0038] In addition to the simplified installation described above, the wheel-end assembly 10 of the present invention offers numerous advantages over previously known wheel-end assemblies. Because the seal unit 16 is pre-installed in the wheel hub 12 as a cartridge seal and supported on the inner bearing race 32, potential damage to the seal 50 during installation by the customer is eliminated, and no surface machining is required on the axle 1 for the seal to operate. By sealing radially outward, the seal 50 is better lubricated by centrifugal force, resulting in reduced wear, friction, lower operating temperatures, and a longer life. Furthermore, the seal efficiency is continuously improved, as lubricant tends to accumulate on the inner surface 13A of the rotating hub 12. Furthermore, the cartridge seal unit 16, with the seal 50 sealing against the outer cover member 64, allows for more accurate assembly of the seal unit 16 in the wheel hub 12 and eliminates potential damage to the seal during assembly and disassembly of the wheel end 10, thereby providing the seal unit 16 with the potential for reuse. Furthermore, the seal unit 16 can be constructed to maintain the relative position of the components of the cartridge seal during assembly of the wheel-end assembly 10 to the axle 1 without employing any buffering devices or other devices, thereby reducing friction and the resulting heat generation of the seal, and eliminating the possibility of such a buffering device or other device being partially worn or sheared off and subsequently entering the seal interface. Furthermore, by retaining the lock nut unit 20 with the retaining member 22, thereby retaining the inner bearing race 42 on the inner side of the compartment, the wheel hub 12 and its bearing units 14 and 18 can be extracted from the axle 1 as a whole.

[0039] Those skilled in the art will appreciate that the above specific embodiments may be modified without departing from the broad inventive concept of the present invention. Therefore, it should be understood that the present invention is not limited to the specific embodiments disclosed, but rather should be understood to encompass various variations within the spirit and scope of the present invention as generally defined by the appended claims.

Claims

1. A wheel end assembly for rotatably coupling a wheel to an axle, the wheel end assembly comprising: A wheel hub is generally cylindrical and can be connected to the wheel, and has an inner axial end portion on the cabin side, an outer axial end portion on the cabin side, and an inner circumferential surface defining a wheel hub hole; The inner bearing is arranged in the wheel hub hole and includes an outer ring connected to the wheel hub, an inner ring located inside the outer ring and capable of being arranged around the axle, and a plurality of rolling elements arranged between the inner and outer rings; a sealing unit connected to the inner race of the inboard bearing and configured to keep the inner race at least partially positioned within the outer race when the wheel end assembly is separated from the axle; an outboard bearing disposed in the wheel hub hole and spaced apart from the inboard bearing at an outboard end portion thereof facing the wheel hub in the axial direction, the outboard bearing comprising an outer ring coupled to the wheel hub, an inner ring disposed inside the outer ring and capable of being disposed around the axle, and a plurality of rolling elements disposed between the inner and outer rings; a nut unit disposed adjacent to the outboard bearing of the pod, comprising a nut configured to threadably engage an outer surface portion of the axle so as to couple the wheel end assembly to the axle; as well as A retaining member is configured to hold the nut unit axially adjacent to the outboard bearing so that the nut unit limits axial displacement of the inner race of the outboard bearing to keep the inner race of the outboard bearing at least partially located within the outer race of the outboard bearing when the wheel-end assembly is separated from the axle.

2. A wheel end assembly for rotatably coupling a wheel to an axle, the wheel end assembly comprising: A wheel hub is generally cylindrical and can be connected to the wheel, and has an inner axial end portion on the cabin side, an outer axial end portion on the cabin side, and an inner circumferential surface defining a wheel hub hole; A bearing is arranged in the wheel hub hole and includes an outer ring coupled to the wheel hub, an inner ring arranged inside the outer ring and capable of being arranged around the axle, and a plurality of rolling elements arranged between the inner and outer rings; and A sealing unit for sealing the annular space between the inner and outer rings of the bearing, wherein the sealing unit is configured to keep the inner ring at least partially located within the outer ring when the wheel-end assembly is separated from the axle; the inner ring has a shoulder, and the shoulder has an outer circumferential surface, and the sealing unit radially engages with the outer circumferential surface of the shoulder and the inner circumferential surface of the hub hole.

3. The wheel end assembly according to claim 2, wherein: The sealing unit is connected to the bearing inner ring and can be sealingly engaged with the wheel hub or a sealing component coupled to the wheel hub, so that the inner ring is substantially prevented from axial displacement when the wheel end assembly is separated from the axle.

4. The wheel end assembly according to claim 3, characterized in that: The sealing unit comprises an annular sealing member which is arranged around the outer surface of the inner ring shoulder and has an outer circumferential sealing lip.

5. The wheel end assembly according to claim 4, characterized in that: The annular seal comprises: an annular rigid base component having an axial portion disposed about the bearing inner ring shoulder and a radial portion extending radially outward from the axial portion; and An annular elastomeric seal assembly is coupled to the base assembly and includes a cantilever portion extending generally axially from a radial portion of the base assembly and having an outer circumferential wedge-shaped portion for providing the sealing lip.

6. The wheel end assembly according to claim 5, characterized in that: The sealing unit further comprises an annular cover member arranged at least partially around the seal, the cover member having an outer circumferential surface and an inner circumferential surface opposite to the outer circumferential surface, the outer circumferential surface frictionally engaging with the inner surface of the hub, the sealing lip sealingly engaging with the inner circumferential surface of the cover member.

7. The wheel end assembly according to claim 6, characterized in that: the cover member includes an axial portion providing inner and outer circumferential surfaces thereof and a radial portion extending inwardly from the axial portion, the radial portion being axially spaced from the bearing outer ring so that the seal is disposed between the bearing outer ring and the radial portion of the cover member; and The elastomeric component of the seal also includes a generally axially extending lip engageable with a radial portion of the cover member.

8. The wheel end assembly according to claim 5, characterized in that: the axial portion of the rigid base component of the seal having an inner circumferential surface and an elastomeric layer disposed on the inner circumferential surface, the elastomeric layer sealing between the rigid base component and the inner ring shoulder; and The sealing unit further includes an annular biasing member configured to bias the cantilever portion of the elastomeric assembly radially outward.

9. The wheel end assembly according to claim 2, characterized in that: The outer ring of the bearing is formed as a bearing cup having an angled inner circumferential surface portion that faces generally toward the inboard end of the hub and provides an outer ring raceway of the bearing; The inner ring of the bearing is formed as a bearing cone having an angled outer circumferential surface portion that faces generally in a direction opposite to the inboard end of the hub and provides an inner ring raceway of the bearing; Each rolling element is formed as a tapered roller and is configured to roll simultaneously on the inner and outer ring raceways of the bearing; and The sealing unit is arranged in the axial direction between the outer ring of the bearing and the inner end of the hub.

10. The wheel end assembly according to claim 2, wherein: The bearing is an inner bearing of the cabin, and the wheel end assembly further includes: an outboard bearing axially spaced from the inboard bearing such that the outboard bearing is axially disposed between the inboard bearing and an outboard axial end of the hub, the outboard bearing comprising an outer ring coupled to the hub, an inner ring disposed within the outer ring, and a plurality of rolling elements disposed between the inner and outer rings; a nut unit disposed adjacent to the outboard bearing, comprising a nut configured to threadably engage an outer surface portion of the axle so as to couple the wheel end assembly to the axle; and The retaining member is configured to keep the nut unit axially adjacent to the outboard bearing so that the nut unit limits axial displacement of the inner ring of the outboard bearing to keep the inner ring of the outboard bearing at least partially located within the outer ring of the outboard bearing when the wheel-end assembly is separated from the axle.

11. The wheel end assembly according to claim 2, wherein: An annular sealing component is also included. The sealing component is coupled to the inner race of the bearing and is configured to seal the outer surface of the axle to prevent leakage between the inner race and the axle.

12. A wheel end assembly for rotatably coupling a wheel to an axle, the wheel end assembly comprising: A wheel hub, which is generally cylindrical and can be connected to the wheel, has an inner axial end portion, an outer axial end portion and an inner circumferential surface defining a wheel hub hole; A bearing is arranged in the wheel hub hole, comprising an outer ring coupled to the wheel hub, an inner ring arranged inside the outer ring and capable of being disposed around the axle, and a plurality of rolling elements located between the inner and outer rings; a nut unit disposed adjacent to the bearing, comprising a nut and a washer, the nut being configured to threadably engage an outer surface portion of the axle shaft so as to couple the wheel end assembly to the axle shaft, the washer being at least partially disposed between the nut and the inner race of the bearing, the nut being movably connected to the washer; and A retaining member is coupled to the wheel hub and can be contacted by the washer to keep the nut unit arranged adjacent to the bearing in the axial direction, so that the nut unit limits the axial displacement of the inner ring of the bearing to keep the inner ring of the bearing at least partially arranged in the outer ring of the bearing when the wheel end assembly is separated from the axle.

13. The wheel end assembly according to claim 12, wherein: The nut has an outer circumferential surface and an annular groove extending radially inward from the outer circumferential surface; The washer comprises an annular body having an inner radial portion and an outer axial portion, the inner radial portion being arranged axially between the nut and the inner ring of the bearing, the outer axial portion having a first end integral with the inner radial portion and a free second end opposite the first end and capable of engaging with a retainer; The nut unit further comprises an annular support having an outer axial portion connected to the washer and an inner radial portion at least partially arranged in the annular groove of the nut for coupling the washer and the nut.

14. The wheel end assembly according to claim 12, wherein: The hub has an annular groove extending radially outward from an inner surface thereof; and The retainer includes an annular disk disposed around the nut, having an outer radial end disposed in the annular groove of the hub, an inner radial end spaced radially outward from the nut, and a radial surface accessible by a washer.

15. The wheel end assembly according to claim 12, wherein: The outer race of the bearing is formed as a bearing cup having an angled inner circumferential surface portion that faces generally toward the outboard axial end of the hub and provides an outer race track of the bearing; The inner race of the bearing is formed as a bearing cone, has an angled outer circumferential surface portion that faces generally in a direction opposite to the outboard end of the hub compartment and provides an inner race raceway of the bearing; Each rolling element is formed as a tapered roller and is configured to roll simultaneously on the inner and outer ring raceways of the bearing; and The retainer is arranged axially between the bearing and the outboard axial end of the hub.

16. A method for assembling a wheel end assembly on an axle, the axle having a central axis, a free end, and an outer circumferential surface formed with a threaded portion, the method comprising the following steps: A wheel end assembly is provided, comprising a wheel hub, wherein the wheel hub has an inboard end portion, an outboard end portion and a wheel hub hole; the inboard bearing is disposed in the wheel hub hole and has an inner ring and an outer ring coupled to the wheel hub; a seal is configured to keep the inner ring of the inboard bearing located within the outer ring of the inboard bearing; the outboard bearing is disposed in the wheel hub hole and has an inner ring and an outer ring coupled to the wheel hub; a nut unit is disposed adjacent to the outboard bearing and has a nut capable of being engaged with an axle by a thread; a retainer is configured to keep the nut unit adjacent to the outboard bearing so as to keep the inner ring of the outboard bearing located within the outer ring of the outboard bearing; Insert the free end of the axle into the inboard end of the hub; Shifting the wheel end assembly along the axis of the axle until the axle passes through the inboard bearing, outboard bearing, and nut unit; and The nut is rotated about the threaded portion on the outer surface of the axle to couple the wheel end assembly to the axle.

17. The method according to claim 16, wherein: The steps of turning the nut include establishing the desired preload or end action with the outboard bearing.

18. The method according to claim 16, wherein The axle has an inner bore, and the method further comprises the steps of: providing a drive shaft having a first end and a second end opposite the first end having an annular flange; Insert the first end of the drive shaft through the outboard end of the hub, through the free end of the axle, and into the inner bore of the axle; displacing the drive shaft along the axis of the axle until the flange of the drive shaft abuts the outboard end of the wheel hub; and Attach the drive shaft's flange to the outboard end of the hub.

19. A wheel end assembly for rotatably coupling a wheel to an axle, the wheel end assembly comprising: A wheel hub, which is generally cylindrical and can be connected to the wheel, has an inner axial end portion, an outer axial end portion and an inner circumferential surface defining a wheel hub hole; A bearing is disposed in a wheel hub hole and includes an outer ring coupled to the wheel hub, an inner ring located inside the outer ring and capable of being disposed around the axle, and a plurality of rolling elements disposed between the inner and outer rings; as well as A sealing unit for sealing the annular space between the inner and outer rings of the bearing. The sealing unit is connected to the inner ring of the bearing and is constructed to seal the inner surface of the hub or the inner circumferential surface of a sealing component connected to the hub radially outward. The inner ring of the bearing has a shoulder, and the shoulder has an outer circumferential surface. The sealing unit is radially engaged with the outer circumferential surface of the shoulder and the inner circumferential surface of the hub hole.

20. The wheel end assembly according to claim 19, wherein: The inner ring of the bearing has a shoulder with an outer circumferential surface, and the sealing unit includes an annular elastomeric sealing component, which is connected to the shoulder of the inner ring and has an outer circumferential wedge portion for providing a sealing lip, which can be sealingly engaged with the inner surface of the wheel hub or the inner surface of the sealing member.

Images