KR102064275B1 - Wheel bearing for vehicle - Google Patents

Abstract

According to an embodiment, a wheel bearing for a vehicle may include an outer ring coupled to a vehicle body; A wheel hub coupled to the outer end of the wheel hub, the outer race of the constant velocity joint being formed in the inner opening in the axial direction, and an orbital forming part formed in the inner end thereof; At least one inner ring coupled to rotate integrally with the wheel hub and preloaded by the orbital forming unit; And a transmission device having a rolling element interposed between the wheel hub and the outer ring to which the at least one inner ring is coupled, wherein the at least one inner ring is in contact with a portion of the rolling element to support and rotatably support the inner ring raceway. An inner inner ring having a raceway formed with a surface and an extension portion extending from the raceway and contacting the orbital forming portion, and a rubber boot coupling portion is formed on an outer circumferential surface of the extension portion.

Description

Automotive Wheel Bearings {WHEEL BEARING FOR VEHICLE}

The present disclosure relates to a wheel bearing for a vehicle having a constant velocity joint integrated structure.

Wheel bearings provided in the vehicle function to rotatably connect wheels (wheels) that are rotating elements to a non-rotating vehicle body or knuckle. Such wheel bearings are rotatably supported by a rolling element through a wheel hub that is integrally coupled to the wheel, an inner ring that is coupled to rotate integrally with the wheel hub, and the wheel hub and the inner ring in an axial direction. It includes an outer ring (outer ring).

As an example of a conventional wheel bearing for a vehicle, a wheel bearing is proposed, which is installed on a drive axle connected to a longitudinal reduction gear of a vehicle, and which is coupled with a constant velocity joint for transmitting power to a wheel. The constant velocity joint has a housing which is formed such that a stem penetrating the center of the wheel hub is elongated, and the wheel hub and the housing are engaged by screwing the threaded part at the outer end of the stem with the nut.

However, in the conventional fastening structure of the wheel bearing and the constant velocity joint, since the coupling between the wheel hub and the housing is made by the housing stem, the stem should be manufactured to a predetermined length or more to maintain the coupling strength. Therefore, there is a problem that the weight of the housing increases, the manufacturing cost increases, and the driving efficiency decreases by the increased weight. In addition, since the wheel bearing to which the constant velocity joint is fastened has a long length in the axial direction, there is a limitation in being applied to a vehicle having various structures.

In order to solve the problems of the conventional wheel bearing described above, a wheel bearing for a vehicle in which a constant velocity joint is interpolated in a wheel hub has been proposed.

However, such a wheel bearing also includes a housing (outer race) of a constant velocity joint inside the wheel hub, which limits the weight of the wheel bearing. Moreover, there is a manufacturing difficulty because the wheel hub and the housing have a toothed fastening structure. In addition, as the constant velocity joint is interpolated inside the wheel hub, the rubber boot for preventing the inflow of foreign matter into the inner end of the wheel hub is not structurally fastened.

Embodiments of the present disclosure are to solve the above-described problems of the prior art, the outer race of the constant velocity joint is integrally formed in the wheel hub, the rubber boot fastening portion is extended to the portion that the inner ring is extended to drive to rotate It provides a wheel bearing for a vehicle to be formed.

The present disclosure provides embodiments of a wheel bearing for a vehicle having a constant velocity joint integrated structure. According to an exemplary embodiment, a wheel bearing for a vehicle may include: an outer ring coupled to a vehicle body; A wheel hub coupled to the outer end of the wheel hub, the outer race of the constant velocity joint being formed in the inner opening in the axial direction, and an orbital forming part formed in the inner end thereof; At least one inner ring coupled to rotate integrally with the wheel hub and preloaded by the orbital forming unit; And a transmission device having a rolling element interposed between the wheel hub and the outer ring to which the at least one inner ring is coupled, wherein the at least one inner ring is in contact with a portion of the rolling element to support and rotatably support the inner ring raceway. An inner inner ring having a raceway formed with a surface and an extension portion extending from the raceway and contacting the orbital forming portion, and a rubber boot coupling portion is formed on an outer circumferential surface of the extension portion.

In one embodiment, the transmission includes a first transmission having a first rolling element rolling between the wheel hub and the outer ring and a second rolling element rolling between the inner inner ring and the outer ring. 2 may include a transmission device.

In one embodiment, the vehicle wheel bearing is coupled between the wheel hub and the outer ring to seal a portion that is open in the outer axial direction and coupled between the inner inner ring and the outer ring in the inner axial direction It may further comprise a second seal device for sealing the open portion.

In one embodiment, the wheel bearing for a vehicle may further include a rubber boot having a coupling end portion inserted into the rubber boot coupling portion and a clamp for pressing the coupling end to couple the rubber boot to the inner ring. .

In one embodiment, the rubber boot fastening portion may include at least one fastening groove formed in the circumferential direction on the outer circumferential surface of the extension.

In one embodiment, the coupling end of the rubber boot may have an inner circumferential surface formed with at least one protrusion fitted into the at least one fastening groove and an outer circumferential surface formed with a binding surface to which the clamp is coupled.

In one embodiment, the entire width of the at least one fastening groove may be equal to or less than the width of the clamp.

In one embodiment, the axial length of the extension may be 5mm or more and 30mm or less.

In one embodiment, the extension may be manufactured to be separated from the track and disposed at an inner axial position than the track to engage the rubber boot.

In one embodiment, the at least one inner ring may further include an outer inner ring disposed on the axial outer side of the inner inner ring.

In one embodiment, the transmission has a first transmission having a first rolling element rolling in the motion between the outer inner ring and the outer ring and a second rolling element having a rolling motion between the inner inner ring and the outer ring. 2 may include a transmission device.

In one embodiment, the vehicle wheel bearing is coupled between the outer inner ring and the outer ring to seal a portion that is opened in the outer axial direction and coupled between the inner inner ring and the outer ring in the inner axial direction It may further comprise a second seal device for sealing the open portion.

In one embodiment, the outer circumferential surface of the wheel hub includes an outer inner ring engaging surface on which the outer inner ring is disposed and an inner inner ring engaging surface on which the inner inner ring is disposed, wherein the outer inner ring engaging surface is radially than the inner inner ring engaging surface. It may have a stepped shape located on the outside.

In one embodiment, the vehicle wheel bearing further comprises an annular spacer coupled to the wheel hub to be disposed between the outer inner ring and the inner inner ring, the outer inner ring on an upper portion of the outer axial cross section of the spacer. The inner inner ring may contact the lower portion of the inner axial cross section of the spacer.

In one embodiment, a plurality of grooves may be formed on the surface of the wheel hub to form the outer race spaced apart in the circumferential direction.

In an embodiment, the vehicle wheel bearing may include an inner race of a constant velocity joint accommodated inside the outer race and having an axle coupling; A cage disposed between the outer race and the inner race; And a plurality of balls maintained at a distance from each other by the cage and disposed at each of the plurality of grooves.

In one embodiment, at least a portion of the outer race may be located axially outward than the outer surface of the inner inner ring.

In one embodiment, the center of rotation of the inner race may be located axially outward than the inner surface of the inner inner ring.

According to the embodiments of the present disclosure, since the outer race of the constant velocity joint is integrally formed on the wheel hub, the coupling structure of the wheel bearing and the constant velocity joint can be simplified and the weight of the wheel bearing can be reduced. That is, the manufacturing cost of a wheel bearing can be reduced and manufacturing productivity can be improved.

In addition, since the rubber boot fastening portion is formed on the inner ring that rotates relative to the outer ring, the rubber boot can be easily fastened without making structural changes to the wheel bearing or using an additional fastening part.

1 is a cross-sectional view of a wheel bearing for a vehicle according to an embodiment of the present disclosure.
2 is a cross-sectional view of a wheel hub according to an embodiment of the present disclosure.
3 is a cross-sectional view of the inner ring according to an embodiment of the present disclosure.
4 is a cross-sectional view of the outer ring according to an embodiment of the present disclosure.
5 is a perspective view of a wheel bearing for a vehicle according to an embodiment of the present disclosure.
FIG. 6 is a perspective view of the vehicle wheel bearing according to the exemplary embodiment of the present disclosure viewed from a direction different from that of FIG. 5.
7 is a cross-sectional view of a wheel bearing for a vehicle in which a rubber boot is fastened according to an embodiment of the present disclosure.
8 is a perspective view of a wheel bearing for a vehicle in which a rubber boot is fastened according to an embodiment of the present disclosure.
FIG. 9 is an enlarged view of a portion A shown in FIG. 7.
10 is a view showing another example of the rubber boot fastening portion shown in FIG.
11 is a diagram illustrating another example of an inner ring according to an exemplary embodiment of the present disclosure.
12 is a cross-sectional view of a wheel bearing for a vehicle according to another embodiment of the present disclosure.
13 is a cross-sectional view of a wheel bearing for a vehicle in which a rubber boot is fastened according to another embodiment of the present disclosure.
FIG. 14 is an enlarged view of a portion B shown in FIG. 12.

Embodiments of the present disclosure are illustrated for the purpose of describing the technical spirit of the present disclosure. The scope of the present disclosure is not limited to the embodiments set forth below or the detailed description of these embodiments.

All technical and scientific terms used in the present disclosure, unless defined otherwise, have the meanings that are commonly understood by one of ordinary skill in the art to which this disclosure belongs. All terms used in the present disclosure are selected for the purpose of more clearly describing the present disclosure, and are not selected to limit the scope of the rights according to the present disclosure.

As used in this disclosure, expressions such as "comprising", "including", "having", and the like, are open terms that imply the possibility of including other embodiments unless otherwise stated in the phrase or sentence in which the expression is included. It should be understood as (open-ended terms).

As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Expressions such as “first”, “second”, and the like used in the present disclosure are used to distinguish a plurality of components from each other, and do not limit the order or importance of the components.

In this disclosure, when a component is said to be "connected" or "coupled" to another component, that component can be directly connected to or coupled to another component, or a new different configuration It is to be understood that the elements may be connected or combined via media.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the accompanying drawings, the same or corresponding components are given the same reference numerals. In addition, in the following description of the embodiments, it may be omitted to duplicate the same or corresponding components. However, even if the description of the component is omitted, it is not intended that such component is not included in any embodiment.

In the accompanying drawings, arrow 'D1' points along the axis of rotation (RA) of the wheel bearings to indicate the outer axial direction (axially outward) where the wheel is engaged with respect to the wheel hub, and arrow 'D2' is the opposite direction of D1. As an inner axial direction (axial direction inner side). In the following, the direction of rotation axis RA of the wheel bearing may be simply referred to as 'axial direction'. Further, the arrow 'D3' points to the outer radial direction (radial outward) away from the rotation axis RA in the radial direction with respect to the rotation axis RA of the wheel bearing, and the arrow 'D4' is the opposite direction to D3. The inner radial direction (radial inner side) is indicated. In addition, the arrow 'D5' indicates the direction of rotation about the rotation axis RA, that is, the circumference direction.

A wheel bearing for a vehicle according to embodiments of the present disclosure (hereinafter, simply referred to as 'wheel bearing') has a structure in which at least one inner ring is coupled to a wheel hub. That is, the wheel bearing has a structure in which a hub raceway surface is formed in the wheel hub so that one inner ring is coupled or a pair of inner races in which the inner raceway surfaces are formed, respectively. Such wheel bearings may be referred to as so-called third-generation wheel bearings and fourth-generation wheel bearings depending on the number of combined inner rings.

1 is a cross-sectional view of a wheel bearing 1000 according to one embodiment of the present disclosure.

Referring to FIG. 1, the wheel bearing 1000 of one embodiment includes a wheel hub 100 coupled to a wheel at an outer end thereof, an inner ring 200 coupled to the wheel hub 100, and an inner ring 200 coupled thereto. It includes an outer ring 300 for rotatably supporting the rolling elements 410A, 410B by inserting the combined wheel hub 100 in the axial direction.

The wheel hub 100 has a hub flange 101 formed on the outer circumferential surface 110 so as to extend radially outwardly D3. The hub flange 101 is formed with a bolt fastener 102 to which a hub or wheel type bolt (not shown) can be fastened, and the wheel hub 100 can be coupled with a wheel through the hub flange 101. have. The centering portion 103 may protrude from the outer axial end of the wheel hub 100 to easily fit the center of the wheel on the rotation shaft RA.

The wheel hub 100 may be rotatably supported by directly contacting a part of the rolling element 410A. One inner ring 200 is coupled to the wheel hub 100, and a portion of the first seal apparatus 500A is coupled to the wheel hub 100.

At the inner end of the wheel hub 100 is formed an orbital forming unit 120 that can appropriately apply a pre-load to the inner ring 200 is coupled. The orbital forming part 120 is a plastic deformation of the inner axial end of the wheel hub 100 to extend in the outer radial direction D3. The orbital forming part 120 applies a preload to the inner ring 200 in contact with the inner ring. It can function to prevent the axial movement of the (200).

The outer race 130 of the constant velocity joint is integrally formed inside the wheel hub 100 toward the axially inner side D2. That is, the wheel hub 100 may itself function as the outer race 130 of the constant velocity joint.

The outer race 130 may be formed in a size larger than the hemisphere and smaller than the sphere. A plurality of grooves 132 are formed on the surface 131 forming the outer race 130 of the wheel hub 100. The surface 131 forming the outer race 160 may be referred to as a raceway, and may be heat treated to improve strength.

The wheel bearing 1000 is an inner race 140 accommodated inside the outer race 130 to have an integral velocity joint-integrated structure, and a cage disposed between the outer race 130 and the inner race 140. , 150) and a plurality of transmission balls 160 that are spaced apart from each other in the circumferential direction D by the cage 150 and disposed in each of the plurality of grooves 132. An inner race 140 is formed with an axle coupler 141, and the axle 10 (see FIG. 7) may be coupled to transmit power to the wheels. The wheel bearing 1000 in which the constant velocity joint is integrally formed may transmit power even at a large angle without causing a change in rotational speed or torque between the driving shaft and the driven shaft.

The wheel bearing 1000 has a structure in which the inner race 140 is located inside the wheel hub 100 so as to have an improved joint angle. That is, when the wheel bearing 1000 is viewed from a cross section taken along the rotation axis RA, at least a part of the outer race 130 is axially outward from the cross section 201 facing the outer axial direction D1 of the inner ring 200. It is located at (D1). In addition, the center of rotation RC of the inner race 140 is located in the axial direction D1 than the end face 202 facing the inner axial direction D2 of the inner ring 200. The rotation center RC of the inner race 140 may be determined as a position where an imaginary line connecting the rotation centers of the balls 160 disposed in the radial direction meets the rotation axis RA.

The inner ring 200 rotatably supporting the rolling element 410B located in the axially inner side D2 of the rolling elements 410A and 410B provided in a double row in the wheel bearing 1000 is an inner inner ring (inboard side inner ring). Can be referred to. In one embodiment, the inner ring 200 has an orbital portion 210 that contacts and supports a portion of the rolling element 410 so as to be rotatably supported, and extends from the orbital portion 210 to the axially inner side D2 and the orbital forming portion 120. ) Includes an extension 220. In the assembly structure of the wheel bearing 1000, the track portion 210 is located inside the outer ring 300 and the extension portion 220 is located outside the outer ring 300. A rubber boot fastening part 250 is formed on the outer circumferential surface of the extension part 220 of the outer circumferential surface 230 of the inner ring 200, which will be described in detail later.

The outer ring 300 is a cylindrical body in which the wheel hub 100 and the inner ring 200 can be fitted. The outer ring 300 includes an outer ring flange 330 protruding from the outer circumferential surface 310 in the outer radial direction D3. A bolt fastener 331 is formed on the outer ring flange 330, and the outer ring 300 may be fastened to a knuckle that is a non-rotating body through a bolt (not shown) fastened to the bolt fastener 331.

The wheel bearing 1000 includes a transmission device to allow relative rotation of the wheel hub 100 and the inner ring 200 with respect to the outer ring 300. In one embodiment, the transmission comprises a first transmission 400A and a second transmission 400B arranged in a double row. The first transmission device 400A includes a plurality of first rolling elements 410A rolling in the rolling motion between the wheel hub 100 and the outer ring 300 and a plurality of first rolling elements 410A arranged in the circumferential direction D5. It includes a first cage (420A) for keeping the spaced apart from each other. In addition, the second transmission apparatus 200B includes a plurality of second rolling bodies 410B which perform a rolling motion between the inner ring 200 and the outer ring 300 and a plurality of second rolling elements arranged in the circumferential direction D5 ( And a second cage 420B for keeping 410B apart from each other. In the wheel bearing 1000 of the exemplary embodiment, the first and second rolling bodies 410A and 410B may be formed in a ball type. However, the types of the first and second rolling elements 410A and 410B are not limited thereto.

First and second portions between the inner circumferential surface 320 of the outer ring 300 and the outer circumferential surface 110 of the wheel hub 100 spaced apart from the inner circumferential surface 320 of the outer ring 300 and the outer circumferential surface 230 of the inner ring 200. A bearing space 401 is formed through which the transmissions 400A, 400B can be interposed. The wheel bearing 1000 blocks the foreign matter from entering the bearing space 401 and prevents leakage of grease injected into the bearing space 401 from the first seal device 500A and the second seal. Device 500B. The first seal device 500A may be coupled between the wheel hub 100 and the outer ring 300 to seal the portion 402 that is open in the outer axial direction D1 of the bearing space 401. The second seal device 500B may be coupled between the inner ring 200 and the outer ring 300 to seal a portion 403 that is opened in the inner axial direction D2 of the bearing space 401. These first and second seal devices 500A and 500B may form a labyrinth sealing structure.

2 is a cross-sectional view of the wheel hub 100 according to an embodiment of the present disclosure. 2 shows the wheel hub 100 before the orbital forming unit 120 is formed.

Referring to FIG. 2, the wheel hub 100 is rotatably supported by contacting a portion of the first rolling element 410A on the outer circumferential surface 110 positioned at the axially inner side D2 of the hub flange 101. The raceway surface 111 is provided. In addition, the wheel hub 100 has a hub raceway surface of the inner ring engaging surface 112 to which the inner ring 200 is fitted to the outer circumferential surface 110 and the seal engaging surface 113 to which a part of the first seal device 500 is coupled. It is provided in the both sides of 111. When viewed from the cross section taken along the axial direction RA, the hub raceway surface 111 has an arc shape, and the outer circumferential surface 110 of the wheel hub 100 has a stepped shape. That is, the seal engaging surface 113 is located radially outward (D3) than the hub raceway surface 111, the hub raceway surface 111 is located radially outward (D3) than the inner ring engaging surface (112). The wheel hub 100 may be in contact with a cross section 201 toward the outer axial direction D1 of the inner ring 200 coupled to the stepped portion between the hub raceway 111 and the inner ring engaging surface 112. The hub raceway 111 may be heat treated to improve strength.

The inner axial end 104 of the wheel hub 100 is formed to have an outer circumferential surface extending from the inner ring engaging surface 112 in the inner axial direction D2, so that the inner ring 200 is formed before the orbital forming unit 120. The wheel hub 100 may be coupled to be axially fitted.

A plurality of grooves 132 are formed on the surface 131 forming the outer race 130 inside the wheel hub 100, and the plurality of grooves 132 may be spaced apart from each other in the circumferential direction D5. .

3 is a cross-sectional view of the inner ring 200 according to an embodiment of the present disclosure.

Referring to FIG. 3, the inner ring 200 has a cylindrical or similar shape. A portion of the wheel hub 100 is inserted into the hole 200H penetrating in the axial direction of the inner ring 200 to contact the inner ring engaging surface 112 of the wheel hub 100 with the inner circumferential surface 240 of the inner ring 200.

The inner ring 200 has an inner ring raceway surface 231 that rotatably supports a portion of the second rolling element 410B on the outer circumferential surface 230. In addition, the inner ring 200 has an outer circumferential surface 233 of the seal coupling surface 232 to which a portion of the second seal device 500B is coupled to the outer circumferential surface 230 and the extension portion 220 where the rubber boot coupling portion 250 is formed. ). The inner ring raceway surface 231 and the seal coupling surface 232 may constitute an outer circumferential surface of the raceway 210. When the inner ring 200 is viewed from a cross section taken along the axial direction RA, the inner ring raceway surface 231 has an arc shape, and the seal engagement surface 232 is formed of the inner raceway surface 231 and the extension portion 220. It is located in the radially outer side D3 than the outer peripheral surface 233. The inner ring raceway surface 231 of the outer circumferential surface 230 of the inner ring 200 may be heat-treated to improve strength.

The inner ring 200 is moved in the axial direction until the end surface 201 facing the outer axial direction D1 contacts the stepped portion between the hub raceway 111 and the inner ring engaging surface 112 of the wheel hub 100. The orbital forming part 120 formed on the wheel hub 100 is in contact with the end face 202 facing the inner axial direction D2.

4 is a cross-sectional view of the outer ring 300 according to an embodiment of the present disclosure.

Referring to FIG. 4, the outer ring 300 has a hole 300H into which the wheel hub 100 and a portion of the inner ring 200 may be fitted. The outer ring 300 is rotatable in contact with a portion of the first outer ring raceway surface 321 and the second rolling element 410B that rotatably contacts and contacts a portion of the first rolling element 410A on the inner circumferential surface 320. It has a second outer ring raceway surface 322 to be supported. The first outer ring raceway surface 321 faces the hub raceway surface 111, and the second outer raceway raceway surface 322 faces the inner raceway raceway surface 232. In addition, the outer ring 300 has a second seal coupling surface to which a portion of the first seal coupling surface 323 and a portion of the second seal apparatus 500B are coupled to the inner circumferential surface 320. 324. The first seal coupling surface 323 is opposed to the seal coupling surface 113 of the wheel hub 100, and the second seal coupling surface 324 is opposite to the seal coupling surface 232 of the inner ring 200. When viewed from the cross section taken along the axial direction RA, the first outer ring 321 and the second outer ring raceway surface 322 have an arc shape, and the first seal engaging surface 323 and the second ring. The seal engagement surface 324 is located radially outward D3 than the first outer raceway surface 321 and the second outer raceway surface 322.

A knuckle may slide on the outer circumferential surface 310 of the outer ring 300 and may be coupled to a bolt fastened to the bolt fastener 331 of the outer ring flange 330.

5 is a perspective view of a wheel bearing 1000 according to an embodiment of the present disclosure.

Referring to FIG. 5, in the wheel bearing 1000, the wheel hub 100 has one hub flange 101 extending in the outer radial direction D2, and the outer ring 300 has the outer radial direction D2. It has a plurality of outer ring flange 330 protruding into the.

A plurality of bolt fasteners 102 are formed in the hub flange 101 formed in one shape along the circumferential direction D5, and the plurality of bolt fasteners 102 are spaced apart from each other in the circumferential direction D5. do. The hub flange 101 may further include a bolt fastener 105 to fasten the bolt coupled to the disk (or drum) provided in the wheel. The centering portion 103 may be formed in a cylindrical shape at the outer axial end of the wheel hub 100.

The outer ring 300 has a plurality of outer ring flange 330 is formed to face different outer radial direction (D3), the bolt fastener 331 is formed in each of the plurality of outer ring flange 330.

6 is a perspective view of the wheel bearing 1000 according to the exemplary embodiment of the present disclosure, viewed from a direction different from that of FIG. 5.

Referring to FIG. 6, the outer race 130 of the constant velocity joint is formed inside the wheel hub 100, and the inner race 140 is formed inside the outer race 130 that is open toward the inner axial direction D2. The cage 150 and the plurality of balls 160 are disposed and coupled. An axle may be inserted into and coupled to the axle coupler 141 of the inner race 140. The wheel bearing 1000 having the constant velocity joint integrated structure may be easily applied to a vehicle having various structures due to a short axial length.

The rubber boot coupling part 250 is formed at the extension part 220 of the inner ring 200 which is located in the axially outer side of the outer ring 300 and the orbital forming part 120 contacts. When the rubber boot is fastened to the wheel bearing 1000, at least a part of the extension part 220 is wrapped by the rubber boot, and the rubber boot fastening part 250 is an extension part 220 so that a part of the rubber boot can be fitted. It may be formed in the form of a groove concave in the circumferential direction (D5) on the outer circumferential surface of.

7 is a cross-sectional view of the wheel bearing 1000 to which the rubber boot 20 is fastened according to an embodiment of the present disclosure.

Referring to FIG. 7, the wheel bearing 1000 according to an embodiment may include a rubber boot 20 having a coupling end inserted into a rubber boot coupling part 250 formed at the extension part 220 of the inner ring 200. It may further include a clamp 30 for pressing the coupling end of the rubber boot 20 to couple the rubber boot 20 to the inner ring 200.

The rubber boot 20 has a corrugated pipe shape in which both ends are open, and a coupling end positioned in the outer axial direction D1 is coupled to the inner ring 200. In FIG. 7, the inner axial end opposite the engaging end of the rubber boot 20 is shown spaced apart from the axle 10, but the inner axial end of the rubber boot 20 engages the axle 10. Can be.

Clamp 30 may be of a band type having a predetermined width that is bound to the coupling end of the rubber boot 20, the clamp to securely secure the coupling end of the rubber boot 20 to the inner ring 200 It may include a tightening device that can adjust the length of (30).

8 is a perspective view of a wheel bearing 1000 to which the rubber boot 20 is fastened according to an embodiment of the present disclosure.

Referring to FIG. 8, the outer ring 300 is coupled to a vehicle body or knuckle that does not rotate through the outer ring flange 330, and a hub flange 101 in the wheel hub 100 that is driven to rotate relative to the outer ring 300. The wheel is coupled through In the inner ring 200 which is driven to rotate relative to the outer ring 300 integrally with the wheel hub 100, the rubber boot coupling part 250 is provided in the extension part 220, which is a portion extending in the inner axial direction D2. It is formed, the coupling end of the rubber boot 20 toward the outer axial direction (D2) is coupled to the rubber boot fastening portion 250 by the clamp 30 (see Fig. 7). The rubber boot 20 has a corrugated pipe shape in which both ends thereof are opened so that the axle 10 may be disposed inside, and the constant velocity joint and the axle 10 are integrally formed with the wheel hub 100 as shown in FIG. 8. The sealing portion of the can be sealed from the outside to prevent foreign substances from entering.

An end opening toward the inner axial direction D2 opposite to the engaging end of the rubber boot 20 may be coupled to the axle 10, in which case the rubber boot 20 is the inner ring 200 and the axle 10. It can be rotated integrally with.

FIG. 9 is an enlarged view of a portion A shown in FIG. 7.

Referring to FIG. 9, the rubber boot coupling part 250 includes a coupling groove 251 formed in the circumferential direction on the outer circumferential surface 233 of the extension part 220 of the inner ring 200. Corresponding to the rubber boot fastening part 250, the rubber boot 20 has a coupling end part of which is inserted into the rubber boot fastening part 250. In one embodiment, the coupling end of the rubber boot 20 has an inner circumferential surface 21 having at least one protrusion 22 fitted into the fastening groove 251 and a binding surface 24 to which the clamp 30 is coupled. It has an outer circumferential surface 23. The protrusion 22 may be formed along the circumferential direction D5 at the inner circumferential surface 21 of the engaging end. The fastening groove 251 and the at least one protrusion 22 fitted into the fastening groove 251 form a labyrinth sealing structure to prevent foreign matter from penetrating between the inner ring 200 and the rubber boot 20. have.

At least one slit 25 may be formed on the binding surface 24 to which the clamp 30 of the rubber boot 20 is bound, and the protrusion 22 is fastened by the clamp 30. The engagement end of the rubber boot 20 may be deformed so as to be firmly fitted in the 251.

In one embodiment, the fastening groove 251 is formed to have a width W ₁ that is less than or equal to the width W ₂ of the clamp 30. When the width W _{1 of the} fastening groove 251 exceeds the width W _{2 of the} clamp 30, the influence of the clamping force of the clamp 30 may be affected only on a part of the protrusion 22 fitted in the fastening groove 251. Since the rubber boot 20 is greatly extended, the rubber boot 20 may not be firmly fastened to the rubber boot fastening part 250 and may move in the axial direction.

In addition, in one embodiment, the extension 220 of the inner ring 200 has an axial length L of 5 mm or more and 30 mm or less. That is, the extension part 220 has an axial length L of at least 5 mm or more for firm and stable fastening of the rubber boot 20, and exceeds 30 mm in consideration of weight reduction and the position of the orbital forming part 120. It does not have a length to

In the inner ring 200, at least one concave groove 234 may be further provided on the outer circumferential surface 233 of the extension part 220 to improve sealing performance of the rubber boot 20. In this case, the clamp 30 preferably has a width W ₂ that can cover up to a part of the engaging end of the rubber boot 20 in contact with the at least one concave groove 234.

10 is a view showing another example of the rubber boot fastening portion shown in FIG.

Referring to FIG. 10, the rubber boot fastening part 250 according to another embodiment includes a plurality of fastening grooves 251 and 252 to improve sealing performance through a labyrinth structure. Corresponding to the rubber boot fastening part 250, the rubber boot 20 may have a protrusion 22 fitted on at least one of the plurality of fastening grooves 251 and 252 on one end side inner circumferential surface 21.

11 is a diagram illustrating another example of an inner ring according to an exemplary embodiment of the present disclosure.

Referring to FIG. 11, the track part 210 and the extension part 220 of the inner ring 200 may be manufactured in a separate shape. That is, the extension part 220 is manufactured to be separated from the track part 210 and is disposed at a position in the inner axial direction D2 than the track part 210 and is configured to engage with the rubber boot 20.

The track part 210 may perform the function of an independent inner ring, and the extension part 220 fitted between the track part 210 and the orbital forming part 120 may form a rubber boot fastening part 250. Can perform the function of.

In the following, an embodiment of a wheel bearing having a structure in which a rolling element is not rotatably supported by a wheel hub directly and a pair of inner rings are coupled is described. With respect to such a wheel bearing, the components having the shape and structural differences from the above-described wheel bearing 1000 will be mainly described, and the same or similar components will be briefly described or omitted.

12 is a cross-sectional view of a wheel bearing 1000A according to another embodiment of the present disclosure.

Referring to FIG. 12, the wheel bearing 1000A according to another embodiment includes a pair of inner rings 200A and 200B coupled to the wheel hub 100A. Among the pair of inner rings 200A and 200B, the inner ring 200A disposed at the relatively axially outer side D1 is called an outer inner ring (outboard side inner ring), and the inner ring is disposed at the axial inner side D2 of the outer inner ring. 200B is called an inner outer ring (inboard side inner ring).

The wheel hub 100A has an inner inner ring engaging surface contacting the outer inner ring engaging surface 111A contacting the inner circumferential surface 220A of the outer inner ring 200A and the inner inner surface 220B of the inner inner ring 200B on the outer circumferential surface 110A. 112A). In one embodiment, the outer inner ring 200A and the inner inner ring 200B are formed to have different inner diameters, so that the outer circumferential surface 110A of the wheel hub 100A has a stepped shape. Specifically, the outer circumferential surface 110A of the wheel hub 100A has a stepped shape in which the outer inner ring engaging surface 111A is located at a radially outer side D3 than the inner inner ring engaging surface 112A.

An outer circumferential surface 210A of the outer inner ring 200A is provided with a raceway surface that contacts and partially rotates the first rolling element 410A, and a second rolling element is formed on the outer circumferential surface 210B of the inner inner ring 200B. And a raceway surface that is rotatably supported in contact with a portion of 410B. In addition, the outer circumferential surface 210A of the outer inner ring 200A is provided with a seal engaging surface to which a part of the first seal device 500A is coupled, and the second seal device 500B is provided on the outer circumferential surface 210B of the inner inner ring 200B. It is provided with a seal coupling surface to which a portion of the coupling.

The inner inner ring 200B in which the rubber boot coupling part 250 is formed may have the same configuration as the inner ring 200 of one embodiment.

13 is a cross-sectional view of the wheel bearing 1000A to which the rubber boot 20 is fastened according to another embodiment of the present disclosure.

Referring to FIG. 13, the wheel bearing 1000A of another embodiment includes a wheel hub 100A having a wheel coupled to an outer end thereof, an outer inner ring 200A and an inner outer ring 200B coupled to rotate integrally with the wheel hub 100A. ), The outer ring (300A) for rotatably supporting the rolling elements (410A, 410B) by inserting the wheel hub (100A) coupled to the outer inner ring (200A) and the inner inner ring (200B) in the axial direction.

The wheel hub 100A has a hub flange 101 formed on the outer circumferential surface 110A so as to extend radially outwardly D3. A bolt fastener 102 is formed at the hub flange 101, and the wheel valve 100A may be coupled to the wheel through the hub flange 101. The centering part 103 may also protrude from the wheel hub 100A.

An orbital forming part 120 is formed at an inner end of the wheel hub 100A so as to properly apply preload to the outer inner ring 200A and the inner inner ring 200B.

The outer race 130 of the constant velocity joint is integrally formed inside the wheel hub 100A, which is open toward the axially inner side D2. The outer race 130 may be formed in a size larger than the hemisphere and smaller than the sphere. A plurality of grooves 132 are formed on the surface 131 forming the outer race 130 of the wheel hub 100A. The surface 131 forming the outer race 160 may be heat treated to improve strength.

The wheel bearing 1000A has an inner race 140 accommodated inside the outer race 130 so as to have a constant velocity joint integrated structure, a cage 150 and a cage disposed between the outer race 130 and the inner race 140. And a plurality of transmission balls 160 which are held apart from each other in the circumferential direction D by 150 and are disposed in each of the plurality of grooves 132. The inner race 140 has an axle coupler 141 is formed, the axle 10 may be coupled to transmit power to the wheel.

Also in the wheel bearing 1000A, the inner race 140 has a structure in which the inner race 140 is located inside the wheel hub 100A so as to have an improved cutting angle. That is, when the wheel bearing 1000A is viewed from the cross section taken along the rotation axis RA, at least a part of the outer race 130 is axially outward (D1) than the cross section facing the outer axial direction D1 of the inner inner ring 200B. ) In addition, the center of rotation RC of the inner race 140 is located in the axial direction D1 rather than the cross section facing the inner axial direction D2 of the inner inner ring 200B.

The inner inner ring 200B rotatably supporting the second rolling element 410B located in the axially inner side D2 of the first and second rolling elements 410A and 410B provided in a double row in the wheel bearing 1000A. Is an orbital portion 210 which contacts with a part of the second rolling element 410B so as to be rotatably supported, and is extended from the orbital portion 210 to the axially inner side D2 and the orbital forming portion 120 is in contact. The unit 220 is included.

The outer ring 300A is a cylindrical body in which the wheel hub 100A and the outer and inner inner rings 200A and 200B are fitted, and the outer ring flange 330 protrudes in the outer radial direction D3 from the outer circumferential surface 310. It is provided. A bolt fastener 331 is formed at the outer ring flange 330, and the outer ring 300 may be fastened to a knuckle, which is a non-rotating body, through the outer ring flange 330.

The wheel bearing 1000A includes a plurality of first rolling elements 410A rolling in a rolling motion between the outer inner ring 200A and the outer ring 300 and a plurality of first rolling elements 410A arranged in the circumferential direction D5. A first transmission device 400A having a first cage 420A spaced apart from each other, a plurality of second rolling bodies 410B and a circumferential direction in which rolling motion is performed between the inner inner ring 200B and the outer ring 300. And a second transmission device 400B having a second cage 420B for keeping the plurality of second rolling bodies 410B arranged in D5) apart from each other.

The first and the first between the inner circumferential surface 320 of the outer ring 300A and the outer circumferential surface 210A of the outer inner ring 200A and the outer circumferential surface 210B of the inner inner ring 200B spaced from the inner circumferential surface 320 of the outer ring 300A. 2 The bearing space 401 in which the transmissions 400A and 400B can be interposed is formed. The wheel bearing 1000A blocks the inflow of foreign matter into the bearing space 401 and the first seal device 500A and the second seal to prevent leakage of grease injected into the bearing space 401. Device 500B.

The wheel bearing 1000A may further include a rubber boot 20 coupled to the inner inner ring 200B, which is a rotating body, by the clamp 30.

The fastening structure of the rubber boot fastening part 250 and the rubber boot 20 formed on the inner inner ring 200B is the same as the fastening structure of the rubber boot fastening part 250 and the rubber boot 20 of the wheel bearing 1000 described above. can do.

In addition, the axial length of the extension part in which the rubber boot coupling part 250 of the inner inner ring 200B is formed may be the same as the axial length L of the extension part 220 of the wheel bearing 1000 described above.

In addition, the inner inner ring 200B may have a shape in which the track portion and the extension portion are separated like the inner ring 200 of the wheel bearing 1000 described above.

FIG. 14 is an enlarged view of a portion B shown in FIG. 12.

Referring to FIG. 14, the wheel bearing 1000A of another embodiment may further include an annular spacer 600 coupled to the wheel hub 100A to be disposed between the outer inner ring 200A and the inner inner ring 200B. .

The outer inner ring 200A and the inner inner ring 200B having different inner diameters coupled to the stepped outer circumferential surface 110A of the wheel hub 100A are difficult to directly contact with a large area. In this case, as the orbital forming unit 120 is formed at the wheel hub 100A, a preload applied to the inner inner ring 200B may not be transmitted to the outer inner ring 200A. In this embodiment, the outer inner ring 200A is in contact with the upper portion of the outer axial cross section 610 of the spacer 600, and the inner inner ring 200B is in the lower portion of the inner axial cross section 620 of the spacer 600. ), The preload applied to the inner inner ring 200B can be properly transmitted to the outer inner ring 200A through the spacer 600.

The outer inner ring 200A has an outer circumferential surface 110A such that the inner inner ring 200B subjected to the preload can move on the outer circumferential surface 110A of the wheel hub 100A to push the spacer 600 and the outer inner ring 200A in the axial direction. It may have a length projecting in the inner axial direction than the stepped portion of the).

While the technical spirit of the present disclosure has been described with reference to some embodiments and the examples shown in the accompanying drawings, the technical spirit and scope of the present disclosure may be understood by those skilled in the art. It will be appreciated that various substitutions, modifications, and alterations can be made in the scope. Also, such substitutions, modifications and variations are intended to be included within the scope of the appended claims.

10: axle 20: rubber boot
30: clamp 100, 100A: wheel hub
200, 200A, 200B: inner ring 210: track portion
220: extension portion 250: rubber boot fastening portion
300, 300 A: outer ring 400: transmission
500: seal device 600: spacer
1000, 1000A: wheel bearing

Claims (18)

Outer ring coupled to the vehicle body;
A wheel hub having a wheel coupled to the outer end and having an outer race of a constant velocity joint formed therein, the inner hub being open toward the inner axial direction, and having an orbital forming part plastically deformed to extend in the outer radial direction at the inner end;
At least one inner ring coupled to rotate integrally with the wheel hub and preloaded by the orbital forming unit; And
A transmission device having a rolling element interposed between the wheel hub and the outer ring to which the at least one inner ring is coupled,
The at least one inner ring is
An inner inner ring having a track portion formed with an inner ring raceway surface rotatably supporting the rolling element in contact with a portion of the rolling element, and an extension portion extending from the track portion to contact the orbital forming portion,
The rubber wheel fastening portion is formed on the outer circumferential surface of the extension portion located in the outer axial direction of the orbital forming portion from the inside of the outer ring in the axial direction. The method of claim 1,
The transmission device
A first transmission having a first rolling element rolling between the wheel hub and the outer ring; And
And a second transmission having a second rolling element rolling in rolling motion between the inner inner ring and the outer ring. The method of claim 2,
A first seal device coupled between the wheel hub and the outer ring to seal a portion that is opened in an outer axial direction; And
And a second seal device coupled between the inner inner ring and the outer ring to seal a portion opened in the inner axial direction. The method of claim 1,
A rubber boot having a coupling end part of which is inserted into the rubber boot fastening part; And
And a clamp for pressing the engaging end to couple the rubber boot to the inner ring. The method of claim 4, wherein
The rubber boot fastening part includes at least one fastening groove formed in a circumferential direction on an outer circumferential surface of the extension part. The method of claim 5,
The coupling end of the rubber boot has an inner circumferential surface formed with at least one protrusion fitted into the at least one fastening groove and an outer circumferential surface formed with a binding surface to which the clamp is coupled. The method of claim 5,
And the overall width of the at least one fastening groove is less than or equal to the width of the clamp. The method of claim 1,
The axial length of the extension is a vehicle wheel bearing, 5mm or more and 30mm or less. The method of claim 4, wherein
And the extension part is manufactured to be separated from the track part and disposed at an inner axial position than the track part and configured to engage with the rubber boot. The method of claim 1,
The at least one inner ring further comprises an outer inner ring disposed axially outward of the inner inner ring. The method of claim 10,
The transmission device
A first transmission device having a first rolling element rolling between the outer inner ring and the outer ring; And
And a second transmission having a second rolling element rolling in rolling motion between the inner inner ring and the outer ring. The method of claim 11,
A first seal device coupled between the inner inner ring and the outer ring to seal a portion axially open between the outer inner ring and the outer ring;
And a second seal device coupled between the inner inner ring and the outer ring to seal a portion axially open between the inner inner ring and the outer ring. The method of claim 10,
The outer circumferential surface of the wheel hub includes an outer inner ring engaging surface on which the outer inner ring is disposed and an inner inner ring engaging surface on which the inner inner ring is disposed, and the outer inner ring engaging surface is radially outward from the inner inner ring engaging surface. Vehicle wheel bearing having a shape. The method of claim 13,
And an annular spacer coupled to the wheel hub so as to be disposed between the outer inner ring and the inner inner ring,
And the outer inner ring contacts the upper portion of the outer axial cross section of the spacer and the inner inner ring contacts the lower portion of the inner axial cross section of the spacer. The method of claim 1,
A plurality of grooves are circumferentially spaced apart from the surface forming the outer race of the wheel hub, the vehicle wheel bearing. The method of claim 15,
An inner race of a constant velocity joint accommodated inside the outer race and having an axle coupler;
A cage disposed between the outer race and the inner race; And
And a plurality of balls that are spaced apart from each other by the cage and disposed in each of the plurality of grooves. The method of claim 16,
At least a portion of the outer race is located axially outward from an outer surface of the inner inner ring. The method of claim 16,
And a center of rotation of the inner race is located axially outward from an inner side surface of the inner inner ring.

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