Bearing device for wheel

Abstract

In a bearing device (1) for a wheel provided with an outer ring (2) (outer member), a hub ring (3), an inner ring (4) (inner member), balls (8) (rolling elements), and an outer-side seal member (10) (seal member), the outer-side seal member (10) has a core bar (11) and a seal part (12), and the seal part (12) has: a protruding part (12e) that protrudes toward the inside and comes into contact with an outer-side end surface (2g) of the outer ring (2); and a protruding section (12f) that is disposed radially outward of the protruding section (12e), protrudes toward the inside, and is in contact with the chamfered section (2h) of the outer ring (2).

Description

Technical Field

[0001] The present invention relates to a wheel bearing device. Background Art

[0002] Conventionally, there is a known wheel bearing device for automobiles. The wheel bearing device comprises: an outer ring (outer member) having an outer raceway surface formed on the inner circumference; an inner ring (inner member) having an inner raceway surface opposite to the outer raceway surface of the outer ring; a plurality of balls (rolling elements) freely sandwiched between the two raceway surfaces of the outer ring and the inner ring; and a sealing member that blocks an opening formed in the space between the outer ring and the inner ring (see Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2020 / 012953 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In a wheel bearing device, the sealing member has a protrusion that contacts the inner circumference of the outer ring (or the outer side end face of the outer ring), so that the sealing performance between the sealing member and the inner circumference of the outer ring is improved. However, due to the intrusion of muddy water and the like into the protrusion side, the protrusion deteriorates and the sealing performance between the sealing member and the inner circumference of the outer ring may not be maintained.

[0008] Therefore, an object of the present invention is to provide a wheel bearing device that can suppress muddy water and the like from entering the protrusion portion and can maintain the sealing performance of the protrusion portion for a relatively long period of time.

[0009] Means for solving problems

[0010] The camshaft is an axially parallelogram of the wheel bearing, wherein the camshaft has an inner surface that is parallel to the outer surface of the wheel bearing and an outer surface that is parallel to the outer surface of the wheel bearing. The camshaft has an inner surface that is parallel to the outer surface of the wheel bearing. The camshaft has an inner surface that is parallel to the outer surface of the wheel bearing. The camshaft has an inner surface that is parallel to the outer surface of the wheel bearing.

[0011] Effects of the Invention

[0012] The present invention has the following effects.

[0013] That is, according to the invention of the present application, muddy water and the like can be suppressed from entering the protrusion portion side, and the sealing performance of the protrusion portion can be maintained for a relatively long period of time. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a cross-sectional view showing a wheel bearing device according to one embodiment of the present invention.

[0015] Figure 2 It is an enlarged cross-sectional view showing the same wheel bearing device.

[0016] Figure 3 It is an enlarged cross-sectional view showing an outer side sealing member of the same wheel bearing device.

[0017] Figure 4 It is an enlarged cross-sectional view showing the same wheel bearing device. DETAILED DESCRIPTION

[0018] Below, use Figures 1 to 4 A wheel bearing device 1 according to one embodiment of the wheel bearing device of the present invention will be described.

[0019] like Figure 1 or Figure 2 As shown, the wheel bearing device 1 supports the wheel rotatably in the suspension device of a vehicle such as an automobile. The wheel bearing device 1 includes an outer ring 2 as an outer member, a hub ring 3 as an inner member, an inner ring 4, two inner ball rows 5 as rolling rows, an outer ball row 6, an inner side sealing member 9 as a sealing member, and an outer side sealing member 10 as a sealing member. Here, in this specification, the inner side refers to the vehicle body side of the wheel bearing device 1 when the wheel bearing device 1 is mounted on the vehicle body, and the outer side refers to the wheel side of the wheel bearing device 1 when the wheel bearing device 1 is mounted on the vehicle body. In addition, the direction parallel to the rotation axis of the wheel bearing device 1 is represented as "axial direction", the direction orthogonal to the rotation axis of the wheel bearing device 1 is represented as "radial direction", and the direction along the arc centered on the rotation axis of the wheel bearing device 1 is represented as "circumferential direction".

[0020] The outer ring 2 supports the hub ring 3 and the inner ring 4 via the inner ball row 5 and the outer ball row 6. The outer ring 2 is formed in a substantially cylindrical shape. An inner outer raceway surface 2c and an outer outer raceway surface 2d are provided on the inner diameter surface of the outer ring 2. A vehicle body mounting flange 2e for mounting on the steering knuckle of the suspension device is integrally formed on the outer peripheral surface of the outer ring 2.

[0021] The wheel hub 3 supports the wheel of the vehicle so that it can rotate freely. The wheel hub 3 is formed in a cylindrical shape. A small-diameter step portion 3a with a reduced diameter of the outer circumferential surface is formed at the inner side end of the wheel hub 3. A wheel mounting flange 3b for mounting the wheel is integrally formed at the outer side end of the wheel hub 3. Hub bolts 3d are inserted through the circumferentially equally divided positions of the wheel mounting flange 3b. In addition, the wheel hub 3 is configured so that the inner track surface 3c on the outer side is opposite to the outer track surface 2d on the outer side of the outer ring 2. The inner ring 4 is embedded in the small-diameter step portion 3a of the wheel hub 3.

[0022] An annular space is formed between the inner diameter surface of the outer ring 2 and the outer diameter surface of the hub ring 3. An inner opening 2a is formed at the inner side end of the annular space formed between the outer ring 2 and the hub ring 3, into which the inner side sealing member 9 can fit. An outer opening 2b is formed at the outer side end of the annular space formed between the outer ring 2 and the hub ring 3, into which the outer side sealing member 10 can fit. The boundary portion between the outer diameter outer surface 2f of the outer ring 2 and the outer side end surface 2g is formed by C chamfering. The chamfered portion of the outer ring 2 is formed as a chamfered portion 2h. The chamfered portion 2h of the outer ring 2 is chamfered, so that the cross is relatively small.

[0023] The inner ring 4 applies preload to the inner ball row 5 and the outer ball row 6. An annular inner raceway surface 4a is formed along the circumferential direction on the outer peripheral surface of the inner ring 4. The inner ring 4 is fixed to the inner side end of the hub ring 3 by riveting. That is, the inner raceway surface 4a is formed by the inner ring 4 on the inner side of the hub ring 3. The inner ring 4 is arranged in such a way that its inner raceway surface 4a is opposed to the outer raceway surface 2c on the inner side of the outer ring 2.

[0024] The inner ball row 5 and the outer ball row 6 hold a plurality of balls 8 as rolling elements in an annular shape by a resin retainer 7. The inner ball row 5 is freely rollably sandwiched between the inner raceway surface 4a of the inner ring 4 and the outer raceway surface 2c on the inner side of the outer ring 2. The outer ball row 6 is freely rollably sandwiched between the inner raceway surface 3c of the hub ring 3 and the outer raceway surface 2d on the outer side of the outer ring 2.

[0025] The cage 7 holds the balls 8. The cage 7 is made of a synthetic resin having excellent oil resistance, wear resistance, and lubricity, such as polyamide 46 (PA46), polyamide 66 (PA66), polyamide 9T (PA9T), polyetheretherketone (PEEK), polyphenylene sulfide (PPS), etc. In addition, the resin may contain glass fiber or carbon fiber as a reinforcing material.

[0026] The balls 8 are made of steel balls made of high-carbon chromium bearing steel SUJ2, etc. The plurality of balls 8 are rotatably held in the pockets Pt of the cage 7 .

[0027] The inner sealing member 9 closes an inner opening 2 a of an annular space formed between the outer ring 2 and the hub ring 3 .

[0028] like Figure 2 As shown, the outer side sealing member 10 blocks the opening 2b on the outer side of the annular space formed between the outer ring 2 and the hub ring 3. The outer side sealing member 10 includes: a core metal 11, which is formed into a substantially cylindrical shape by forming a steel plate of the same material as the sealing plate; and a sealing portion 12, which is fixed to the core metal 11 and is integrally formed with the core metal 11.

[0029] The core metal 11 of the outer sealing member 10 is formed in an annular shape and has a cylindrical portion 11 a , an inner diameter portion 11 b , and a circular plate portion 11 c .

[0030] The cylindrical portion 11a is pressed into the inner circumference of the end portion on the outer side of the outer ring 2 with a predetermined interference. The inner diameter portion 11b is bent and extended radially inward from the cylindrical portion 11a. The circular plate portion 11c extends radially outward from the cylindrical portion 11a and is in close contact with the outer end face 2g of the outer ring 2. By making the circular plate portion 11c in close contact with the outer end face 2g of the outer ring 2, the outer side sealing member 10 can be positioned with high precision in the state of being arranged at the opening portion 2b on the outer side, and the sealing performance of the outer side sealing member 10 to the opening portion 2b on the outer side can be improved.

[0031] The seal portion 12 of the outer seal member 10 is made of synthetic rubber such as NBR (acrylonitrile butadiene rubber), and includes a grease lip 12a, a first side lip 12b, a second side lip 12c, a weir portion 12d, a protrusion 12e, and a projection 12f.

[0032] The grease lip 12a of the sealing portion 12 extends from the radially inner end of the core metal 11 toward the radially inner and inner sides. The front end of the grease lip 12a contacts the outer peripheral surface 3e of the hub ring 3. The first side lip 12b is arranged at a position radially outward from the grease lip 12a and extends radially outward and outward. The front end of the first side lip 12b contacts the outer peripheral surface 3e of the hub ring 3 at a position radially outward from the front end of the grease lip 12a. The second side lip 12c is arranged at a position radially outward from the first side lip 12b and extends radially outward and outward. The front end of the second side lip 12c contacts the outer peripheral surface 3e of the hub ring 3. The weir portion 12d is formed to cover the circular plate portion 11c of the core metal 11 and protrude radially outward from the core metal 11. The weir portion 12d is formed to protrude radially outward from the outer side end surface 2g of the outer ring 2.

[0033] The portion of the disc portion 11 c of the core metal 11 from the radially intermediate portion to the radially outer end portion is configured such that the inner surface is cut away and the portion is slightly thinner than other portions. The thin-walled portion of the disc portion 11 c is covered by the sealing portion 12 .

[0034] The protrusion 12e of the sealing portion 12 is configured to protrude from the thin-walled portion of the sealing portion 12 disposed on the circular plate portion 11c of the core metal 11 toward the inner side (the outer side end face 2g side of the outer ring 2 in the axial direction). The protrusion 12e is configured to have a protruding length to the inner side of about 0.2mm to 0.3mm. The protrusion 12e is configured to be annular. The protrusion 12e is formed to be approximately triangular in cross-section such that the radial width becomes narrower as it approaches the inner side. The protrusion 12e is elastically deformed and contacts the outer side end face 2g of the outer ring 2 when the outer side sealing member 10 is disposed in the opening portion 2b on the outer side.

[0035] Thus, the protrusion 12e of the sealing portion 12 protrudes toward the inner side (the outer side end face 2g side of the outer ring 2) and contacts the outer side end face 2g of the outer ring 2, thereby improving the sealing performance between the outer side sealing member 10 and the outer side end face 2g of the outer ring 2 (outer member).

[0036] The metal core 11 is not disposed in the protrusion 12e of the sealing portion 12. With this configuration, the protrusion 12e is relatively easy to elastically deform, and the operation of pressing the outer sealing member 10 into the outer opening 2b can be relatively easy.

[0037] The protrusion 12f of the sealing portion 12 is arranged at a position radially outward from the protrusion 12e. The protrusion 12f is configured to protrude from the sealing portion 12 disposed at the thin-walled portion of the disc portion 11c of the core metal 11 toward the inner side (the outer side end surface 2g side of the outer ring 2 in the axial direction). The protrusion 12f is configured in an annular shape. The protrusion 12f is configured to be longer than the protrusion 12e in the inner side. The radial outer surface of the protrusion 12f is composed of a surface substantially parallel to the axial direction, the radial inner surface of the protrusion 12f is composed of a surface inclined relative to the axial direction, and the inner side surface of the protrusion 12f (the inner side end surface) is composed of a surface substantially orthogonal to the axial direction. That is, the protrusion 12f is formed in a substantially trapezoidal shape. In a state where the outer side sealing member 10 is arranged at the opening 2b on the outer side, the protrusion 12f (the radial inner side inclined surface of the protrusion 12f) elastically deforms and contacts the chamfered portion 2h of the outer ring 2.

[0038] In this way, the sealing portion 12 has a protrusion 12f which is arranged at a position radially outward from the protrusion 12e and protrudes toward the inner side (the outer side end face 2g side of the outer ring 2 in the axial direction) and contacts the chamfered portion 2h of the outer ring 2. This can prevent muddy water and the like from entering the protrusion 12e side (radially inner side) from the protrusion 12f, and can maintain the sealing performance of the protrusion 12e to the outer side sealing member 10 and the outer side end face 2g of the outer ring 2 (outer member) for a relatively long time.

[0039] The protrusion length of the protrusion 12f toward the inner side (the outer end surface 2g side of the outer ring 2 in the axial direction) is preferably configured to be 0.5 mm or more. By configuring in this way, muddy water and the like can be more reliably prevented from entering the protrusion 12e side (radially inner side) from the protrusion 12f.

[0040] The protruding length of the protruding portion 12f toward the inside is preferably configured to be 2.0 mm or less. With this configuration, it is possible to suppress deformation that would impair the functionality of the protruding portion 12f when the outer sealing member 10 is pressed into the outer opening 2b.

[0041] Here, Figure 2 The following describes the line A, point B, and line C shown. Line A is an imaginary line extending radially outward from the center position P of the balls of the outer ball row 6 in a manner orthogonal to the axial direction. Point B indicates the position where the outer diameter outer side surface 2f of the outer ring 21 intersects with line A. Line C is an imaginary line extending from point B to the outside in the axial direction.

[0042] The radially outer surface of the protrusion 12f of the seal portion 12 is located radially inward of the outer diameter outer surface 2f of the outer ring 2. The radially outer surface of the protrusion 12f is located radially inward of the line C.

[0043] By configuring the radial thickness of the protrusion 12f so that the radially outer surface of the protrusion 12f is located radially inward of the line C, deformation that may impair the functionality of the protrusion 12f when the outer sealing member 10 is pressed into the outer opening 2b can be suppressed.

[0044] The chamfered portion 2h of the outer ring 2 is preferably configured to have an inclination angle of 45° or less with respect to the axial direction. With such a configuration, muddy water or the like can be more reliably suppressed from entering the protrusion 12e side from the protrusion 12f.

[0045] The chamfered portion 2h of the outer ring 2 is preferably inclined at an angle of 10° or more relative to the axial direction. This configuration can prevent deformation that would impair the functionality of the protrusion 12f from occurring when the outer sealing member 10 is pressed into the outer opening 2b.

[0046] The radially inner side surface of the protrusion 12f of the sealing portion 12 (the surface in contact with the chamfered portion 2h of the outer ring 2) is preferably configured to be inclined at an angle of 20° or less (0° or more and 20° or less) on the axial side relative to the chamfered portion 2h of the outer ring 2. By configuring in this way, it is possible to suppress deformation that would impair the functionality of the protrusion 12f when the outer side sealing member 10 is pressed into the outer side opening 2b.

[0047] The metal core 11 is not disposed in the protruding portion 12f of the sealing portion 12. With this configuration, the protruding portion 12e is relatively easy to elastically deform, and the operation of pressing the outer sealing member 10 into the outer opening 2b can be relatively easy.

[0048] It should be noted that the radially inner side surface of the protrusion 12 f may be configured as a labyrinth lip so as not to contact the chamfered portion 2 h of the hub wheel 3 .

[0049] use Figure 3 Modifications of the sealing portion 12 will be described. Figure 3 In the illustrated embodiment, a part of the structure of the sealing portion 12 is different, and the same components and portions or components and portions having the same functions are denoted by the same reference numerals, and detailed description thereof is omitted.

[0050] like Figure 3 As shown, the radial inner side surface of the protrusion 12f of the sealing portion 12 (the surface in contact with the chamfered portion 2h of the outer ring 2) has a concavoconvex portion 12g. The concavoconvex portion 12g is provided at the inner side end of the radial inner side surface of the protrusion 12f. The concavoconvex portion 12g is configured in a stripe shape. By configuring in this way, the contact pressure generated by the surface of the protrusion 12f in contact with the chamfered portion 2h can be configured to be relatively high, and muddy water and the like can be more reliably suppressed from entering the protrusion 12e side (radially inner side) from the protrusion 12f. It should be noted that the concavoconvex portion 12g is not limited to being configured in a stripe shape, and can also be configured as a convex portion having a plurality of dot shapes.

[0051] use Figure 4 Modifications of the sealing portion 12 will be described. Figure 4 In the illustrated embodiment, a part of the structure of the sealing portion 12 is different, and the same components and portions or components and portions having the same functions are denoted by the same reference numerals, and detailed description thereof is omitted.

[0052] like Figure 4 As shown, the weir portion 12d of the sealing portion 12 does not protrude radially outward from the outer diameter outer side surface 2f of the outer ring 2, but is located radially inward from the outer diameter outer side surface 2f of the outer ring 2. The radial position of the radial outer end surface of the weir portion 12d is configured to be substantially consistent with the radial position of the radial outer end surface of the protrusion 12f, and the radial outer end surface of the weir portion 12d is continuous with the radial outer end surface of the protrusion 12f.

[0053] The sealing portion 12 has a third side lip 12h and a fourth side lip 12i. The third side lip 12h is arranged at a position radially outward from the second side lip 12c, and extends radially outward and externally. The front end portion of the third side lip 12h contacts the outer peripheral surface 3e of the hub ring 3. It should be noted that the structure in which the front end portion of the third side lip 12h does not contact the outer peripheral surface 3e of the hub ring 3 can also be configured as a labyrinth lip. The fourth side lip 12i is arranged at a position radially outward from the third side lip 12h, and extends radially outward and externally. The front end portion of the fourth side lip 12i is close to the outer peripheral surface 3e of the hub ring 3, but does not contact it, and is configured as a labyrinth lip. It should be noted that the front end portion of the fourth side lip 12i can also be configured to contact the outer peripheral surface 3e of the hub ring 3. By configuring in this way, muddy water and the like can be suppressed from entering the radial inside.

[0054] The embodiments of the present invention are described above, but the present invention is not limited to such embodiments but is merely exemplified. Of course, it can be further implemented in various ways within the scope of the main purpose of the present invention. The scope of the present invention is shown by the description of the scope of the claims, and also includes the equivalent meanings recorded in the scope of the claims and all changes within the scope.

[0055] Description of Reference Numerals

[0056] 1Wheel bearing device

[0057] 2 Outer ring (outer member)

[0058] 2a Inner side opening

[0059] 2b External opening

[0060] 2c Outer surface track surface

[0061] 2d outer surface orbital surface

[0062] 2e flange

[0063] 2f outer diameter outer side

[0064] 2g External side end surface

[0065] 2h chamfering part

[0066] 3. Hub (inner member)

[0067] 3a Path Steps

[0068] 3b flange

[0069] 3c inner track surface

[0070] 3d wheel hub bolts

[0071] 3e outer surface

[0072] 4Inner ring (inner square component)

[0073] 4a Inner track surface

[0074] 5 internal side ball rows

[0075] 6 external side ball rows

[0076] 7 Retainer

[0077] 8 Balls

[0078] 9Inner side sealing member

[0079] 10 External side sealing member

[0080] 11 Core Bone

[0081] 12 Sealing part

[0082] 12a Grease lip

[0083] 12b First side lip

[0084] 12c Second side lip

[0085] 12d Weir

[0086] 12e protrusion

[0087] 12f protrusion

[0088] 12g concave and convex part

[0089] 12h third side lip

[0090] 12i fourth side lip.

Claims

1. A wheel bearing device, comprising: An outer member having an outer track surface formed on the inner periphery; An inner square member, which is formed with an inner track surface opposite to the outer track surface; A plurality of rolling elements are sandwiched between the two track surfaces of the outer member and the inner member in a manner that allows for free rolling; and a sealing member that closes an opening of an annular space formed between the outer member and the inner member, It is characterized in that The outer member has a chamfered portion formed by chamfering a boundary portion between an outer diameter outer side surface and an end surface of the outer member, The sealing member comprises a core and a sealing portion fixed to the core. The sealing portion has: a protrusion that protrudes toward the outer member side in the axial direction and contacts the end surface of the outer member; as well as The protrusion is arranged at a radially outer side than the protrusion, protrudes toward the outer member in the axial direction, and contacts the chamfered portion of the outer member.

2. The wheel bearing device according to claim 1, characterized in that: The protrusion length of the protrusion toward the outer member is configured to be greater than or equal to 0.5 mm.

3. The wheel bearing device according to claim 1, characterized in that: The chamfered portion of the outer member is inclined at an angle of 45° or less with respect to the axial direction.

4. The wheel bearing device according to claim 1, characterized in that: The surface of the protruding portion that contacts the chamfered portion is inclined at an angle of 20° or less with respect to the chamfered portion of the outer member on the axis side.

5. The wheel bearing device according to any one of claims 1 to 4, characterized in that: A surface of the protruding portion that contacts the chamfered portion has a concavo-convex portion.

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