WO2019221552A1

WO2019221552A1 - Wheel bearing assembly

Info

Publication number: WO2019221552A1
Application number: PCT/KR2019/005936
Authority: WO
Inventors: 송영수; 박중양
Original assignee: 주식회사 일진글로벌
Priority date: 2018-05-18
Filing date: 2019-05-17
Publication date: 2019-11-21

Abstract

The present disclosure provides a wheel bearing assembly. The wheel bearing assembly may comprise: a wheel hub having a cavity formed to penetrate same in the axial direction; an inner wheel coupled to the outer peripheral surface of the wheel hub; an outer wheel arranged to be spaced apart from the wheel hub and the inner wheel; a rolling device comprising a first power-transfer body interposed between the outer wheel and the wheel hub, and a second power-transfer body interposed between the outer wheel and the inner wheel; a constant-velocity joint comprising a coupling portion inserted into the cavity of the wheel hub, and a joint portion extending from the coupling portion; and a center bolt inserted into the cavity of the wheel hub from the axially outer end of the wheel hub and configured to couple the constant-velocity joint to the wheel hub. The wheel hub may comprise an orbital forming portion, one surface of which contacts the axially inner end surface of the inner wheel, and the other surface of which contacts the axially outer end surface of the joint portion. The inner wheel may comprise an inner-wheel protruding portion protruding toward the joint portion while being spaced apart from the joint portion.

Description

Wheel bearing assembly

The present disclosure relates to a wheel bearing assembly.

The wheel bearing assembly is a device mounted between the rotating element and the non-rotating element to facilitate the rotation of the rotating element. The wheel bearing assembly of the vehicle rotatably connects the wheel to the vehicle body, thereby providing the function of the vehicle to move. Such a wheel bearing assembly may be classified into a drive wheel wheel bearing that transmits power generated in an engine and a driven wheel wheel bearing that does not transmit a driving force.

The drive wheel wheel bearing assembly includes a rotating element and a non-rotating element. The rotating element is caused to rotate together with the drive shaft by the torque generated by the engine and passed through the transmission. In contrast, the non-rotating element is fixed to the vehicle body, and a transmission device is interposed between the rotating element and the non-rotating element. The driven wheel wheel bearing assembly includes a configuration similar to the drive wheel wheel bearing assembly, but no rotating element is connected to the drive shaft.

Various studies have been conducted to reduce the axial length of the wheel bearing assembly. Attempts have been made, for example, to reduce the axial length of the wheel hub or to reduce the axial length of the outer ring. Alternatively, attempts are being made to reduce the length of knuckles or constant velocity joints assembled to wheel hubs. However, such an attempt may cause a problem of deteriorating the durability of the wheel bearing assembly.

One embodiment of the present disclosure provides a wheel bearing assembly that includes an orbital forming portion and an inner ring that can reduce the axial length of the wheel bearing assembly.

A wheel bearing assembly according to one embodiment of the present disclosure, comprising: a wheel hub having a hollow penetrating in an axial direction; An inner ring coupled on an outer circumferential surface of the wheel hub; An outer ring spaced apart from the wheel hub and the inner ring; A rolling device including a first rolling element interposed between the outer ring and the wheel hub and a second rolling element interposed between the outer ring and the inner ring; A constant velocity joint including a coupling portion inserted into the hollow of the wheel hub and a joint portion extending from the coupling portion; And a center bolt inserted into the hollow of the wheel hub at the axially outer end of the wheel hub and configured to couple the constant velocity joint to the wheel hub, the wheel hub having one side contacting the axially inner end face of the inner ring and the other side being And an orbital forming portion in contact with the axially outer end face of the joint portion, wherein the inner ring may include an inner ring protrusion projecting toward the joint portion and spaced apart from the joint portion.

According to one embodiment, the first preload is applied by the orbital forming part when the orbital forming part is formed, and the second preload may be applied by the axial fastening force of the center bolt when the center bolt is fastened to the constant velocity joint.

According to an embodiment, the first preload may have a size of 5 μm to 20 μm, and the second preload may have a size of 5 μm to 20 μm.

According to one embodiment, the sum of the magnitudes of the first preload and the second preload may be 20 μm to 50 μm.

According to one embodiment, the wheel hub comprises a hollow cylindrical portion and a hub flange extending radially from the cylindrical portion, wherein the first axial distance between the inner flange face of the hub flange and the axial inner tip of the inner ring protrusion is And a second axial distance between the inner flange face and the axially inner end face of the inner ring.

According to one embodiment, the wheel hub comprises a hollow cylindrical portion and a hub flange extending radially from the cylindrical portion, the first axial distance between the inner flange surface of the hub flange and the axially inner tip of the inner ring protrusion. The value subtracted from the third axial distance between the inner flange face of the hub flange and the axial outer cross section of the joint portion can be configured to have a positive value.

According to one embodiment, the axial thickness of the orbital forming portion may be 2.5mm to 3.0mm.

According to one embodiment, it may further include a sealing member disposed in the space between the inner ring protrusion and the joint portion configured to block the inflow of foreign matter.

According to one embodiment, it may further comprise a washer disposed between the center bolt and the wheel hub.

According to one embodiment, the orbital forming portion is formed by bending the forming extension extending in the axial direction of the wheel hub radially outward, and the forming extension is configured to be in close contact with the corner surface between the inner circumferential surface of the inner ring and the axially inner end surface of the inner ring It may include a forming surface.

According to one embodiment, the forming surface, the inclined surface inclined radially inward from the outer peripheral surface of the wheel hub; And a concave surface extending from the inclined surface to be concave radially inward.

According to an embodiment, the angle formed between the inclined surface and the axial direction may be 1 ° to 5 °.

According to one embodiment, the radius of curvature of the concave surface may be 20mm to 30mm.

According to one embodiment, the axial width of the concave surface may be greater than the axial width of the inner ring protrusion.

According to one embodiment, the inner ring protrusion may be located in an area formed by the axial width of the concave surface.

According to one embodiment, the axial distance between the axially inner end of the inner ring protrusion and the axially outer end face of the joint portion may be 0.5 mm to 1.0 mm.

According to an embodiment, the inner ring protrusion may include an inclined surface formed to be inclined from the axially inner end of the inner ring protrusion toward the axially inner end surface of the inner ring.

According to one embodiment, the angle formed between the inclined surface and the axial direction may have a size of 0 ° to 45 °.

According to one embodiment, the radial thickness of the inner ring protrusion may be 0.2 to 0.5 times the radial thickness of the inner ring.

According to one embodiment, the outer diameter of the radially front end of the orbital forming portion may be 0.75 to 0.9 times the outer diameter of the outer peripheral surface of the inner ring.

According to embodiments of the present disclosure, a space in which an orbital forming portion may be disposed in the radially inner side of the inner ring protrusion may be formed by forming an inner ring protrusion that is not in contact with the constant velocity joint on the inner ring. Accordingly, the axial length of the wheel bearing assembly can be reduced.

1 is a cross-sectional view showing the overall configuration of a wheel bearing assembly according to an embodiment of the present disclosure.

2 is a cross-sectional view showing a partial configuration of a wheel bearing assembly according to an embodiment of the present disclosure.

3 is a cross-sectional view illustrating a partial configuration of a wheel bearing assembly according to an embodiment of the present disclosure.

4 is a cross-sectional view illustrating a partial configuration of a wheel bearing assembly according to an embodiment of the present disclosure.

5 is a cross-sectional view showing a partial configuration of a wheel bearing assembly according to an embodiment of the present disclosure.

6 is a cross-sectional view illustrating a configuration in which a sealing member is disposed between an inner ring and a constant velocity joint of the wheel bearing assembly illustrated in FIG. 1.

7 is a cross-sectional view illustrating a shape and inner ring of a wheel hub according to an embodiment of the present disclosure.

FIG. 8 is an enlarged cross-sectional view of a portion M shown in FIG. 7.

1: wheel bearing assembly

10: wheel hub

20: inner ring

30: constant velocity joint

40: paddle

50: center bolt

60: washer

70: cloud device

80: sealing device

100: orbital forming unit

200: inner ring protrusion

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 terms and scientific terms used in the present disclosure have the meanings that are generally understood by those skilled in the art to which the present disclosure belongs unless otherwise defined. 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 intended to include open terms, including the possibility of including other embodiments unless otherwise stated in the phrase or sentence in which the expression is included. -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 the present disclosure, when a component is referred to as being "connected" to another component, the component may be directly connected to the other component, or may be connected via a new other component. It must be understood.

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 present disclosure, "axial direction R" may be defined to mean a direction parallel to the rotational axis of the wheel bearing assembly, and "radial direction" is defined to mean a direction away from the axis of rotation. "Circumferential direction" may be defined to mean a direction surrounding the axial direction (R) around the axial direction (R). In the following, the direction of rotational axis of the wheel bearing assembly may simply be referred to as "axial direction R".

In the present disclosure, the arrow "OA" refers to the axial outboard where the wheel is disposed relative to the wheel hub as the direction along the axial direction R of the wheel bearing assembly, and the arrow "IA" is the opposite direction of the "OA". As axial inboard where the knuckle is disposed relative to the wheel hub. In addition, the arrow "OR" points to the outer radial direction away from the rotation axis in the radial direction with respect to the axis of rotation of the wheel bearing assembly, and the arrow "IR" points to the inner radial direction opposite to OR.

In the present disclosure, “pre-load” may mean a size in which a part of the components constituting the wheel bearing assembly are compressed and elastically deformed by a predetermined force applied in the axial direction during the assembly process. The preload can have a length unit and can be measured, for example, in size in μm.

1 is a cross-sectional view showing the overall configuration of a wheel bearing assembly 1 according to an embodiment of the present disclosure. The wheel bearing assembly 1 may be disposed between the suspension of the vehicle (not shown) and the wheel (not shown) to rotate the wheel relative to the suspension. In one embodiment, the wheel bearing assembly 1 may have a shape that is symmetrical about the axial direction R. FIG. For example, the wheel bearing assembly 1 may consist of a drive wheel wheel bearing assembly.

The wheel bearing assembly 1 may include a wheel hub 10, an inner ring 20, an outer ring 40, a rolling device 70, and a sealing device 80. The suspension can be arranged at the axially inner side IA of the wheel bearing assembly 1 and the wheel can be arranged at the axially outer side OA of the wheel bearing assembly 1. 1, the vehicle body may be located at one side of the wheel bearing assembly 1, and the wheel may be located at the other side of the wheel bearing assembly 1.

The wheel hub 10 may include a cylindrical portion 120 extending in the axial direction R and a hub flange 110 extending radially outward from the cylindrical portion 120. A hollow portion 120a penetrated in the axial direction R may be formed at the central portion of the cylindrical portion 120. Wheel bolts (not shown) may be coupled to the bolt holes 111 penetrated in the axial direction R to the hub flange 110. An orbital forming part 100 bent in the radially outer side OR may be formed at an end portion of the cylindrical portion 120 in the axially inner side IA. The first preload is applied to the wheel bearing assembly 1 in the axial direction by the orbital forming part 100. The first preload may have a size of 5 μm to 20 μm.

The inner ring 20 may be press-fitted on the outer circumferential surface of the cylindrical portion 120 and coupled to the cylindrical portion 120. Thus, the inner ring 20 can rotate with the wheel hub 10. In addition, the inner ring 20 may be made of a metal material having a stronger strength than the wheel hub 10. For example, the inner ring 20 may be press-fitted into the inner ring seating portion 120b formed at the inner side IA of the wheel hub 10.

The outer ring 40 may be spaced apart from each of the wheel hub 10 and the inner ring 20. In addition, the outer ring 40 may be coupled to one side of the suspension device (not shown). That is, the outer ring 40 may be provided as a non-rotating element, and may be configured such that the position does not move after being coupled to one side of the suspension device. The outer ring 40 may, for example, be coupled to a knuckle arm (not shown) of the suspension device and fixed in position.

The outer ring 40 includes a first cylindrical portion 41 extending in the axial direction R, an outer ring flange 43 and a first cylindrical portion 41 extending radially outward from the first cylindrical portion 41. It may include a second cylindrical portion 42 extending from the axial direction inward (IA). The outer ring flange 43 may be formed with a knuckle hole 43a for engagement with a knuckle arm (not shown). The sealing device 80 may be interposed between the inner circumferential surface of the second cylindrical portion 42 and the outer circumferential surface of the inner ring 20.

In one embodiment, the rolling device 70 includes a first rolling element 71 interposed between the outer ring 40 and the wheel hub 10 and a second rolling element interposed between the outer ring 40 and the inner ring 20. 72 may be included. The rolling device 70 may include, for example, a retainer 73 for receiving the first and second

rolling elements

71 and 72. As shown in FIG. 1, one portion of the first rolling element 71 may be rolled in contact with the outer ring 40 at the radially outer side OR, and the other portion of the first rolling element 71 may be rolled. It can be rolled in contact with the wheel hub 10 in the direction inward IR. In addition, one portion of the second rolling element 72 may be rolled in contact with the outer ring 40 at the radially outer side OR, and the other portion of the second rolling element 72 may be at the radially inner side IR. It can be rolled in contact with the inner ring 20. Accordingly, the wheel hub 10 and the inner ring 20 can be stably rotated with respect to the outer ring 40.

The wheel bearing assembly 1 may comprise a constant velocity joint 30 which is engaged at the axially inner side IA of the wheel hub 10. The constant velocity joint 30 may include a coupling part 31 inserted into the hollow 120a of the cylindrical part 120 and a joint part 34 extending from the coupling part 31 and in contact with the orbital forming part 100. Can be. The joint part 34 may constitute, for example, an outer race of the constant velocity joint, and a hollow 32 for coupling an inner race to the inner part of the joint part 34 may be formed. Can be. A groove 35 for coupling a rubber boot (not shown) may be formed at the axially inward (IA) position of the outer circumferential surface of the joint part 34.

The wheel bearing assembly 1 may include a center bolt 50 for coupling the constant velocity joint 30 to the wheel hub 10. The center bolt 50 may include a head part 51 and a threaded bolt part 52. The coupling portion 31 of the constant velocity joint 30 may be formed with a hollow 31a for inserting the tip of the bolt portion 52 of the center bolt. The thread of the bolt portion 52 of the center bolt can be engaged with the thread of the inner circumferential surface 31b of the constant velocity joint engaging portion 31. As such, when the center bolt 50 is fastened to the constant velocity joint 30, the second preload is applied to the wheel bearing assembly 1 by the axial fastening force of the center bolt 50. In addition, the second preload may have a size of 5 μm to 20 μm.

According to the embodiment described above, the sum of the magnitudes of the second preload by the axial fastening force of the center bolt 50 coupled with the first preload and the constant velocity joint 30 by the orbital forming unit 100 is 20 μm. To 50 μm. This sum of the first preload and the second preload can be the final preload applied to the wheel bearing assembly.

The wheel bearing assembly 1 may comprise a washer 60. The radius of the washer 60 may be larger than the radius of the head portion 51 of the center bolt 50. The radius of the axial outer (OA) inlet of the hollow 120a of the cylindrical portion 120 of the wheel hub 10 is greater than the radius of the head portion 51 of the center bolt 50 and smaller than the radius of the washer 60. Can be. Therefore, the axial outer side (OA) front end surface 120c of the cylindrical part 120 and the axial inner side (IA) front end surface 64 of the washer 60 can contact. In addition, the axially outer side (OA) front end surface 62 of the washer 60 may contact the axially inner side (IA) front end surface 53 of the head portion 51. Accordingly, the washer 60 may support the head portion 51 so as not to be inserted into the hollow 120a of the cylindrical portion 120. In addition, since the washer 60 distributes the load applied to the wheel hub 10 when the center bolt 50 and the constant velocity joint 30 are coupled, deformation of the wheel hub 10 may be prevented.

2 is a cross-sectional view showing a partial configuration of a wheel bearing assembly 1 according to an embodiment of the present disclosure. The sealing device 80 may include a first sealing device portion 80a coupled to the outer ring 40 and a second sealing device portion 80b coupled to the inner ring 20. The first sealing device portion 80a may include a first frame 81 pressed into the inner circumferential surface 42a of the second cylindrical portion 42 and a first sealing portion 82 coupled to the first frame 81. Can be. The second sealing device portion 80b is coupled to the second frame 83 pressed into the outer circumferential surface 22 of the inner ring 20 and the axial end inner side IA of the second frame 83. It may include. The first sealing portion 82 may include a plurality of lips 82a in contact or non-contact with the axially outer side (OA) front end surface of the second frame 83. In addition, a sealing portion 85 extending from the encoder 84 to the axial outer side OA may be formed at the radial tip of the encoder 84.

The encoder 84 has a ring shape, and different magnetic poles may be alternately arranged along the circumferential direction. For example, in the encoder 84, the north pole and the south pole are alternately arranged, and a plurality of pole pairs consisting of the north pole and the south pole may be arranged in a plurality of pairs. When the encoder 84 rotates once with the inner ring 20, the magnetic field generated from the encoder 84 changes with a period. A wheel sensor (not shown) located outside of the wheel bearing assembly 1 generates a pulse-shaped signal according to this period, and the ECU of the vehicle is based on the signal, and the rotation angle, rotation speed, or It can be configured to generate information about the direction of rotation.

The inner ring protrusion 200 may extend in the axially inner side IA to be in contact with the joint portion 34 of the constant velocity joint 30. The inner ring protrusion 200 may include a front end surface 206 connected to the outer circumferential surface 22 of the inner ring 20 and having a curved shape. In addition, the inner ring protrusion 200 may include an inclined surface 205 formed to be inclined from the front end surface 206 toward the axially inward (IA) end face 21 of the inner ring 20.

The axially outer side (OA) end face 102 of the orbital forming part 100 of the wheel hub 10 may contact the axially inner side (IA) end face 21 of the inner ring 20. In addition, the axially inward (IA) end face 101 of the orbital forming part 100 may contact the axially outward (OA) end face 301 of the joint part 34.

According to an embodiment, the angle α formed between the inclined surface 205 of the inner ring protrusion 200 and the axial direction R may be, for example, 0 ° to 45 °. The orbital forming part 100 is disposed below the inclined surface 205 so as not to contact the inner ring protrusion 200. Therefore, since the material required for the portion below the inclined surface 205 in the inner ring 20 can be saved, the weight of the inner ring 20 can be reduced.

According to one embodiment, the axial distance G ₁ between the front end face 206 of the inner ring protrusion 200 and the axially outer (OA) end face 301 of the joint part 34 is between 0.5 mm and 1.0 mm. Can be. That is, the distance G ₁ may mean a gap between the inner ring protrusion 200 and the joint part 34, and may have a corresponding size of Equation 1 below.

Equation 1: 0.5≤G ₁ ≤1.0 (Unit: mm)

When the distance G ₁ has a size satisfying Equation 1, foreign matter flowing between the inner ring protrusion 200 and the joint part 34 may be blocked, and the inner ring is driven by an external force during the operation of the wheel bearing assembly 1. Contact between the protrusion 200 and the joint 34 may be prevented from occurring.

According to one embodiment, the radial thickness T ₂ of the inner ring protrusion 200 may be 0.2 to 0.5 times the radial thickness T ₁ of the inner ring 20.

Equation 2: 0.2ХT ₁ ≤T ₂ ≤0.5ХT ₁

When the relationship between the thickness T ₂ and the thickness T ₁ is set as in Equation 2, the thickness T ₂ of the inner ring protrusion 200 occupies less than half of the thickness T ₁ of the inner ring 20. Can be. Accordingly, the radial distance between the inner ring protrusion 200 and the orbital forming portion 100 can be maintained at an appropriate level that satisfies the required rigidity of the inner ring 20. In addition, a sufficient contact area between the orbital forming part 100 and the joint part 34 can be ensured.

3 is a cross-sectional view showing a partial configuration of a wheel bearing assembly 1 according to an embodiment of the present disclosure. According to an embodiment, the outer diameter D _J of the radially distal end 103 of the orbital forming unit 100 may be 0.75 to 0.9 times the outer diameter D _I of the outer circumferential surface 22 of the inner ring 20.

Equation 3: 0.75ХD _I ≤D _J ≤0.9ХD _I

According to Equation 2 described above, the range of the radial thickness of the inner ring protrusion 200 may be determined, and the radial front end position of the orbital forming part 100 may be determined by Equation 3. According to Equations 2 and 3, the tip 103 of the orbital forming part 100 and the inclined surface 205 do not come into contact with each other. Therefore, the axially outer side (OA) end face 102 of the orbital forming part 100 may be in close contact with the axially inner side (IA) end face 21 of the inner ring 20.

According to one embodiment, the front end surface 206 of the inner ring protrusion 200 may be configured as a curved surface convex toward the axial inner side (IA). The radius R _A from the center M ₁ of the curved surface may be smaller than the radial thickness T ₂ of the inner ring protrusion 200 shown in FIG. ₂ . Since the front end surface 206 is formed as a curved surface, the sealing device 80 may be interposed between the inner ring 20 and the outer ring 40 without being caught by the edge of the inner ring 20.

4 is a cross-sectional view showing a partial configuration of a wheel bearing assembly 1 according to an embodiment of the present disclosure. According to one embodiment, the first axial distance between the inner flange surface 112 of the hub flange 110 of the wheel hub 10 and the axial inner (IA) tip surface 206 of the inner ring protrusion 200 ( D ₁ ) may be configured to be greater than the second axial distance D ₂ between the inner flange face 112 and the axially inner IA end face 21 of the inner ring 20. That is, the relationship of Equation 4 below may be established between the first axial distance D ₁ and the second axial distance D ₂ .

Equation 4: D ₁ > D ₂

Since the inner ring protrusion 200 protrudes from the axially inner side (IA) end face 21 of the inner ring 20, a relationship as shown in Equation 4 may be derived.

According to one embodiment, the hub flange has a first axial distance D ₁ between the inner flange surface 112 of the hub flange 110 and the axial inner (IA) tip surface 206 of the inner ring protrusion 200. The value subtracted from the third axial distance D ₃ between the inner flange face 112 of the 110 and the axial outer OA cross section 301 of the joint portion 34 is configured to have a positive value. Can be. That is, the relationship of Equation 5 below may be established between the third axial distance D ₃ and the first axial distance D ₁ .

Equation 5: D ₃ -D ₁ > 0

According to Equation 5, the front end surface 206 of the inner ring protrusion 200 is not in contact with the axially outer (OA) end surface 301 of the joint portion 34. Therefore, deformation of the inner ring 20 due to the contact of the constant velocity joint 30 can be prevented.

5 is a cross-sectional view showing a partial configuration of a wheel bearing assembly 1 according to an embodiment of the present disclosure. According to one embodiment, the axial thickness T ₃ of the orbital forming part 100 may be 2.5 mm to 3.0 mm. That is, the axial thickness T ₃ may have a size corresponding to Equation 6 below.

Equation 6: 2.5≤T ₃ ≤3.0 (unit: mm)

When the thickness T ₃ is smaller than 2.5 mm, since the orbital forming part 100 is formed too thin, plastic deformation may occur in the orbital forming part 100 when an external moment load is applied. In addition, when the thickness T ₃ is greater than 3.0 mm, since the orbital forming part 100 is formed too thick, there may be a problem that processing is difficult due to a large load during orbital forming. Therefore, the orbital forming unit 100 needs to be manufactured to a size within a corresponding range of Equation 6.

6 is a cross-sectional view showing a configuration in which the sealing member 300 is disposed between the inner ring and the constant velocity joint of the wheel bearing assembly 1 shown in FIG. According to one embodiment, the wheel bearing assembly 1 may further include a sealing member 300 disposed in the space between the inner ring protrusion 200 and the joint portion 34 to block the inflow of foreign matter. The sealing member 300 may have a ring shape having a circular cross section. The sealing member 300 may be installed between the inner ring protrusion 200 and the tip 103 of the orbital forming part 100 after the orbital forming part 100 is formed on the wheel hub 10. Then, while the constant velocity joint 30 is coupled to the wheel hub 10, one side of the sealing member 300 and the joint part 34 come into contact with each other.

The sealing member 300 comes into contact with the axially outer side (OA) end face 301 of the joint part 34 at the first contact point C ₁ , and the tip 103 and the second contact point of the orbital forming part 100. (C ₂ ), the inclined surface 205 of the inner ring protrusion 200 may be in contact with the third contact point C ₃ . That is, the sealing member 300 may be sealed in contact with the joint part 34, the orbital forming part 100, and the inner ring protrusion 200 at the first to third contact points C ₁ , C ₂ , and C ₃ , respectively. Can be.

According to the above-described embodiment, since the sealing member 300 is disposed between the inner ring protrusion 200, the orbital forming part 100, and the joint part 34, foreign matter introduced between the inner ring 20 and the constant velocity joint 30. Can be completely blocked. Accordingly, corrosion of the inner ring 20, the wheel hub 10, and the constant velocity joint 30 may be prevented.

FIG. 7 is a cross-sectional view illustrating the pre-formed shape and the inner ring 20 of the wheel hub 10 according to the exemplary embodiment of the present disclosure.

The corner surface 25 may be formed between the axially inner side (IA) end face 21 of the inner ring 20 and the inner circumferential surface 23. For example, the corner surface 25 may be configured as a curved surface. As another example, the corner surface 25 may be formed of an inclined surface and a curved surface starting from the inner circumferential surface 23. In addition, a raceway surface 24 configured to roll the rolling element 72 shown in FIG. 1 may be formed in the inner ring 20. The raceway surface 24 may be connected to the outer circumferential surface 22.

Referring to FIG. 7, the forming extension 100A is shown. The orbital forming part 100 illustrated in FIG. 2 may be formed by bending the forming extension part 100A extending in the axial direction R of the wheel hub 10 to the radially outer side OR. In this process, the forming extension 100A may be in close contact with the inner ring 20 so that a gap does not occur between the forming extension 100A and the inner ring 20.

The forming extension portion 100A may include a forming surface 104A having a shape that generally enters the radially inner side IR. The forming surface 104A may be completely in contact with the corner surface 25 after the forming extension 100A is pressed by the press. The forming surface 104A extends from the inclined surface 105A and the inclined surface 105A inclined radially inward (IR) from the outer circumferential surface 121 of the cylindrical portion 120 of the wheel hub 10 and is radially inward (IA). It may include a concave surface 106A formed to be concave.

Inclined surface (105A) may be formed between the outer peripheral surface 121, the end of the first point (P ₁₎ and the concave surface (106A), a second point at the start (P _2). The concave surface 106A may be formed to start at the second point P ₂ and end at the third point P ₃ that enters the radially inner side IR and then rises again to the radially outer side OR. From the third point P ₃ , the forming outer peripheral surface 101A is formed.

According to the embodiments described above, the outer circumferential surface 121, the inclined surface 105A, the concave surface 106A, and the forming outer circumferential surface 101A may have a shape that continues in succession without an inflection point. Referring to the arrow shown in FIG. 7, after the forming extension 100A is pressed by the press to form the orbital forming unit 100, the third point P ₃ of the forming extension 100A is a corner surface. And a fourth point P ₄ , which is a boundary between the 25 and the axially inner side IA cross section 21. As a result, the forming surface 104A may be brought into close contact with the corner surface 25.

In one embodiment, the axial width X ₁ of the concave surface 106A may be greater than the axial width X ₂ of the inner ring protrusion 200. That is, the concave axial width (X ₂₎ of a surface (106A) axial width (X ₁₎ of the inner ring and the protrusion 200 may have a relationship of the following formula 7.

Equation 7: X ₁ > X ₂

In one embodiment, the inner ring protrusion 200 may be located within an area defined by the axial width X ₁ of the concave surface 106A. That is, both the tip of the inner ring protrusion 200 and the axially inner side (IA) end face 21 of the inner ring 20 may be located in an area formed by the axial width X ₁ of the concave surface 106A.

According to the above-described embodiment, after the forming extension portion 100A is pressed by the press to form the orbital forming portion 100, there is no gap between the forming surface 104A and the corner surface 25, and completely It may be in close contact.

FIG. 8 is an enlarged cross-sectional view of a portion M shown in FIG. 7. For convenience of description, the shape of the forming surface 104A may be somewhat exaggerated than the actual shape.

In an embodiment, the angle β between the inclined surface 105A and the axial direction R may be 1 ° to 5 °. That is, the angle β may have a size corresponding to Equation 8 below.

Equation 8: 1 ° ≤β≤5 °

If the angle β is smaller than 1 °, the forming extension 100A exerts excessive pressure on the inner ring 20, and deformation may occur in the inner ring 20. In addition, when the angle β is larger than 5 °, after the orbital forming part 100 is formed, there may be a gap between the forming surface 104A and the corner surface 25, and the performance of the wheel bearing may be degraded. have. Therefore, when the angle β is formed at 1 ° to 5 °, such a problem does not occur, and the forming surface 104A can be completely in contact with the corner surface 25.

In one embodiment, the radius of curvature R _C of the concave surface 106A may be between 20 mm and 30 mm. The radius of curvature R _C may refer to a straight line distance between the origin O _C and the concave surface 106A. Concave surface 106A may consist of a single arc. That is, the radius of curvature of the concave surface 106A may have a size corresponding to Equation 9 below.

Equation 9: 20≤R _C ≤30 (Unit: mm)

When the radius of curvature of the concave surface 106A is smaller than 20 mm, the thickness of the portion of the forming extension portion 100A in which the concave surface 106A is formed becomes considerably thin, so that the durability of the orbital forming portion 100 is weakened or the forming surface is weakened. Between 104A and the corner surface 25 may not be completely in contact. In addition, when the curvature of the concave surface 106A is larger than 30 mm, the thickness of the portion of the forming extension portion 100A in which the concave surface 106A is formed becomes considerably thick, so that orbital forming may be difficult.

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.

Claims

A wheel hub in which the hollow penetrates in the axial direction;

An inner ring coupled to an outer circumferential surface of the wheel hub;

An outer ring spaced apart from the wheel hub and the inner ring;

A rolling device including a first rolling element interposed between the outer ring and the wheel hub and a second rolling element interposed between the outer ring and the inner ring;

A constant velocity joint including a coupling part inserted into the hollow of the wheel hub and a joint part extending from the coupling part; And

A center bolt inserted into the hollow of the wheel hub at an axially outer end of the wheel hub and configured to couple the constant velocity joint to the wheel hub,

The wheel hub includes an orbital forming portion having one surface in contact with an axially inner end surface of the inner ring and the other surface with an axially outer end surface of the joint portion.

The inner ring includes an inner ring protrusion projecting toward the joint part and spaced apart from the joint part.

Wheel bearing assembly.
The method of claim 1,

When the orbital forming portion is formed, a first preload is applied by the orbital forming portion,

When the center bolt is fastened to the constant velocity joint by the axial fastening force of the center bolt is applied a second preload,

Wheel bearing assembly.
The method of claim 2,

The first preload has a size of 5 ㎛ to 20 ㎛,

The second preload has a size of 5 μm to 20 μm,

Wheel bearing assembly.
The method of claim 2,

The sum of the magnitudes of the first preload and the second preload is 20 μm to 50 μm,

Wheel bearing assembly.
The method of claim 1,

The wheel hub includes a cylindrical portion in which the hollow is formed and a hub flange extending in a radial direction from the cylindrical portion,

Wherein the first axial distance between the inner flange face of the hub flange and the axially inner tip of the inner ring protrusion is greater than the second axial distance between the inner flange face and the axially inner end face of the inner ring,

Wheel bearing assembly.
The method of claim 1,

The wheel hub includes a cylindrical portion in which the hollow is formed and a hub flange extending in a radial direction from the cylindrical portion,

A value obtained by subtracting a first axial distance between the inner flange face of the hub flange and the axial inner leading end of the inner ring protrusion from the third axial distance between the inner flange face of the hub flange and the axial outer end face of the joint portion. Is configured to have a positive value,

Wheel bearing assembly.
The method of claim 1,

The axial thickness of the orbital forming portion is 2.5mm to 3.0mm,

Wheel bearing assembly.
The method of claim 1,

Further comprising a sealing member disposed in the space between the inner ring protrusion and the joint portion configured to block the inflow of foreign matter,

Wheel bearing assembly.
The method of claim 1,

And a washer disposed between the center bolt and the wheel hub,

Wheel bearing assembly.
The method of claim 1,

The orbital forming portion is formed by bending the forming extension extending in the axial direction of the wheel hub radially outward,

Wherein the forming extension includes a forming surface configured to closely contact a corner surface between an inner circumferential surface of the inner ring and an axially inner end surface of the inner ring;

Wheel bearing assembly.
The method of claim 10,

The forming surface,

An inclined surface inclined radially inward from an outer circumferential surface of the wheel hub; And

A concave surface extending from the inclined surface to be concave radially inwardly,

Wheel bearing assembly.
The method of claim 11,

The angle between the inclined surface and the axial direction is 1 ° to 5 °,

Wheel bearing assembly.
The method of claim 11,

The radius of curvature of the concave surface is 20mm to 30mm,

Wheel bearing assembly.
The method of claim 11,

The axial width of the concave surface is greater than the axial width of the inner ring protrusion,

Wheel bearing assembly.
The method of claim 14,

The inner ring protrusion is located in an area defined by an axial width of the concave surface,

Wheel bearing assembly.
The method of claim 1,

The axial distance between the axially inner leading end of the inner ring protrusion and the axially outer end face of the joint portion is 0.5mm to 1.0mm,

Wheel bearing assembly.
The method of claim 1,

The inner ring protrusion includes an inclined surface formed to be inclined from the axially inner end of the inner ring protrusion toward the axially inner end face of the inner ring.

Wheel bearing assembly.
The method of claim 17,

The angle between the inclined surface and the axial direction is 0 ° to 45 °,

Wheel bearing assembly.
The method of claim 1,

The radial thickness of the inner ring protrusion is 0.2 to 0.5 times the radial thickness of the inner ring,

Wheel bearing assembly.
The method of claim 1,

The outer diameter of the radially front end of the orbital forming portion is 0.75 to 0.9 times the outer diameter of the outer peripheral surface of the inner ring,

Wheel bearing assembly.