Wheel bearing device

Abstract

In a wheel bearing device, it is possible to suppress the increase in rotational torque and the decrease in mud and water resistance when the slinger moves to the inner side. [Solution] A wheel bearing device 1, wherein the first elastic member 30 of the outer side seal member 10 has a base portion 31 joined to the inner diameter portion 22 of the core metal 20 and a seal lip 32 extending from the base portion 31, the slinger 40 has a disc portion 42 that contacts the base portion 3g of the hub wheel 3 via the second elastic member 40 and faces the inner diameter portion 22 of the core metal 20 and a protruding portion 44 that protrudes from the disc portion 42 toward the base portion 31 of the first elastic member 30, the second elastic member 50 has a contact portion 41 that contacts the base portion 3g of the hub wheel 3 with an overlap and an end face portion 53 joined to the inner end face of the protruding portion 44 of the slinger 40, and the axial distance between the end face portion 53 of the second elastic member 50 and the base portion 31 of the first elastic member 30 is 0.5 mm or less.

Description

Technical Field

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

Background Art

[0002] Conventionally, as for wheel bearing devices, a configuration is known that includes: an outer member having double-row outer raceway surfaces on the inner periphery; an inner member composed of a hub wheel having a wheel mounting flange for mounting a wheel on the outer side end and a small-diameter stepped portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter stepped portion of the hub wheel, the inner member having double-row inner raceway surfaces facing the double-row outer raceway surfaces; double-row rolling elements rollably accommodated between the raceway surfaces of the outer member and the inner member; and a sealing device that closes the outer-side open end of the annular space formed by the outer member and the inner member. Providing this sealing device prevents foreign matter such as muddy water from entering through the outer-side opening.

[0003] Further, Patent Document 1 describes a sealing device for a wheel bearing device, which is configured such that a core metal provided with a plurality of seal lips is fitted to the outer member, and a metal ring (slinger) is fitted to the hub wheel of the inner member so as to face the core metal. The seal lips of the sealing device are configured by those that come into contact with the slinger and those that are configured not to contact the slinger to form a labyrinth. By configuring the sealing device in this way, low torque is achieved while improving muddy water resistance. Further, in such a sealing device, the disk portion of the slinger comes into contact with the base portion of the wheel mounting flange of the hub wheel via a projection (interference) of an elastic member provided on the disk portion, thereby preventing foreign matter such as muddy water from entering from between the base portion of the wheel mounting flange of the hub wheel and the disk portion of the slinger. In addition, when the disk portion of the slinger is not provided with the projection of the elastic member, there is also a configuration that prevents foreign matter such as muddy water from entering from between the base portion of the wheel mounting flange of the hub wheel and the disk portion of the slinger by sealing a sealing paste between the hub wheel and the slinger.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Patent No. 6774278 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] However, in wheel bearing systems equipped with such sealing devices, it is conceivable that the slinger may move inward (towards the mandrel and away from the hub ring) when subjected to repeated vibrations during vehicle operation, or when the wheel bearing system is deformed under a relatively large load. At this time, the slinger moves up to approximately 0.7 mm relative to the mandrel and hub ring. When the slinger moves in the direction toward the mandrel in this way, the overlap of the seal lip in contact with the slinger may become excessive, potentially leading to an increase in rotational torque. Furthermore, this excessive overlap of the seal lip in contact with the slinger may cause damage to the seal lip or poor contact between the seal lip and the slinger, potentially reducing mud and water resistance.

[0006] Therefore, the present invention aims to provide a wheel bearing device that can suppress the increase in rotational torque and the decrease in mud and water resistance when the slinger moves to the inner side due to repeated vibrations during vehicle operation or deformation of the wheel bearing device due to a relatively large load. [Means for solving the problem]

[0007] That is, an outer member having double rows of outer raceway surfaces on its inner circumference, An inner member comprising a hub ring having a wheel mounting flange on the outer side for attaching a wheel and a small-diameter stepped portion extending axially on its outer circumference, and at least one inner ring press-fitted into the small-diameter stepped portion of the hub ring, having a double row of inner raceway surfaces facing the double row of outer raceway surfaces, A double row of rolling elements is rotatably housed between the raceway surfaces of the outer member and the inner member, A wheel bearing device comprising a sealing device that closes the outer open end of the annular space formed by the outer member and the inner member, The sealing device is A core metal fitted to the outer end of the outer member, A first elastic member integrally joined to the aforementioned core metal, A slinger fitted to the base of the wheel mounting flange on the hub wheel, The slinger comprises a second elastic member joined to the slinger, The aforementioned core metal is A core metal fitting portion that is fitted to the outer end of the outer member, It has an inner diameter portion that extends inward from the core fitting portion, The first elastic member is, A base portion joined to the inner diameter portion of the core metal, It has a seal lip extending from the base toward the wheel mounting flange side, The aforementioned slinger is The second elastic member contacts the base of the wheel mounting flange, and the disc portion faces the inner diameter portion of the core metal in the axial direction, The disc portion has a projection that extends from the outer diameter side end toward the base side of the first elastic member and overlaps with the seal lip when viewed from the radial direction, The second elastic member is A contact portion is located between the disc portion of the slinger and the base of the wheel mounting flange, and contacts the base of the wheel mounting flange with an overlap, The slinger has an end face portion that is joined to the inner side end face of the protruding portion, The axial distance between the end face of the second elastic member and the portion of the base of the first elastic member facing the end face is 0.5 mm or less.

[0008] Furthermore, the outer member has a double row of outer raceway surfaces on its inner circumference, An inner member comprising a hub ring having a wheel mounting flange on the outer side for attaching a wheel and a small-diameter stepped portion extending axially on its outer circumference, and at least one inner ring press-fitted into the small-diameter stepped portion of the hub ring, having a double row of inner raceway surfaces facing the double row of outer raceway surfaces, A double row of rolling elements is rotatably housed between the raceway surfaces of the outer member and the inner member, A wheel bearing device comprising a sealing device that closes the outer open end of the annular space formed by the outer member and the inner member, The sealing device is A core metal fitted to the outer end of the outer member, A first elastic member integrally joined to the aforementioned core metal, A slinger fitted to the base of the wheel mounting flange on the hub wheel, The slinger comprises a second elastic member joined to the slinger, The aforementioned core metal is A core metal fitting portion that is fitted to the outer end of the outer member, It has an inner diameter portion that extends inward from the core fitting portion, The first elastic member is, A base portion joined to the inner diameter portion of the core metal, It has a seal lip extending from the base toward the wheel mounting flange side, The aforementioned slinger is The disc portion that contacts the wheel mounting flange via the second elastic member and faces the inner diameter portion of the core metal in the axial direction, The disc portion has a projection that extends from the outer diameter side end toward the base side of the first elastic member and overlaps with the seal lip when viewed from the radial direction, The second elastic member is The slinger has a contact portion located between the disc portion and the base portion of the wheel mounting flange, which contacts the wheel mounting flange with an overlap, The axial distance between the inner end face of the protrusion in the slinger and the portion of the base of the first elastic member facing the end face is 0.5 mm or less.

Advantageous Effects of Invention

[0009] As the advantageous effects of the present invention, the following effects are achieved. That is, according to the invention of the present application, it is possible to suppress an increase in rotational torque and a decrease in mud water resistance when the slinger moves toward the inner side due to repeated exposure to vibration during traveling of a vehicle, or deformation of the wheel bearing device caused by a relatively large load applied to the wheel bearing device, or the like.

Brief Description of Drawings

[0010] [Figure 1] A cross-sectional view showing a wheel bearing device according to one embodiment of the present invention. [Figure 2] An enlarged cross-sectional view of the outer side opening of the same wheel bearing device. [Figure 3] An enlarged cross-sectional view of the outer side opening of the same wheel bearing device. [Figure 4] An enlarged cross-sectional view of the outer side opening of the same wheel bearing device. [Figure 5] An enlarged cross-sectional view of the outer side opening of the same wheel bearing device. [Figure 6] An enlarged cross-sectional view of the outer side opening of the same wheel bearing device.

Mode for Carrying Out the Invention

[0011] Hereinafter, modes for carrying out the present invention will be described with reference to the accompanying drawings.

[0012] [Overall Configuration of Wheel Bearing Device] The wheel bearing device 1 illustrated in FIG. 1 to FIG. 6 will be described. The wheel bearing device 1 shown in FIG. 1 is an embodiment of the wheel bearing device according to the present invention, and rotatably supports a wheel in a suspension system of a vehicle such as an automobile.

[0013] As shown in Figure 1, the wheel bearing device 1 has a configuration referred to as the third generation, and comprises an outer ring 2 which is an outer member, a hub ring 3 and an inner ring 4 which are inner members, two rows of inner ball rows 5 and outer ball rows 6 which are rolling rows, an inner sealing member 9 and an outer sealing member 10.

[0014] Here, "inner side" refers to the side of the wheel bearing device 1 that is attached to the vehicle body, and "outer side" refers to the side of the wheel bearing device 1 that is attached to the vehicle body. Furthermore, "axial direction" refers to the direction along the rotation axis X of the wheel bearing device 1. The direction perpendicular to the rotation axis of the wheel bearing device 1 is referred to as the radial direction. The direction along the arc centered on the rotation axis of the wheel bearing device 1 is referred to as the circumferential direction. In the following, "cross-section" will be explained as a cross-section that passes through the rotation axis of the wheel bearing device 1 and is parallel to the rotation axis of the wheel bearing device 1.

[0015] The outer ring 2 has an inner outer raceway surface 2c and an outer outer raceway surface 2d. The inner outer raceway surface 2c and the outer outer raceway surface 2d are formed on the inner circumference of the outer ring 2. The inner outer raceway surface 2c is located on the inner side of the outer outer raceway surface 2d. A vehicle body mounting flange 2e for attaching the outer ring 2 to a vehicle body side member is integrally formed on the outer circumference of the outer ring 2. The outer end of the outer ring 2 is configured as an outer end portion 2f.

[0016] A small-diameter stepped portion 3a is formed at the inner end of the outer circumference of the hub wheel 3, which is smaller in diameter than the outer end and extends in the axial direction. A wheel mounting flange 3b for attaching a wheel is integrally formed at the outer end of the hub wheel 3. Multiple bolt holes 3c are formed in the wheel mounting flange 3b. Hub bolts 3d are press-fitted into the bolt holes 3c from the inner side to fasten the hub wheel 3 to the wheel or brake components. Alternatively, the hub wheel 3 may be fastened to the wheel or brake components using wheel bolts.

[0017] The hub ring 3 has an inner raceway surface 3e on the outer side. The inner raceway surface 3e on the outer side is formed on the outer circumference of the hub ring 3 so as to face the outer raceway surface 2d on the outer side of the outer ring 2. In other words, the inner raceway surface 3e on the outer side of the inner member is formed by the hub ring 3. An annular space, the outer side opening 2b, is formed between the outer ring 2 and the hub ring 3. The outer side sealing member 10 is fitted into the outer side opening 2b and prevents foreign matter such as muddy water from entering through the outer side opening 2b. The outer side sealing member 10 is an example of a sealing device.

[0018] The wheel mounting flange 3b of the hub wheel 3 is located on the outer side of the inner raceway surface 3e on the outer side. The flange 3b has a flange side surface 3f facing the inner side. The flange side surface 3f is composed of a flat surface parallel to the radial direction. The vicinity of the bolt holes 3c on the flange side surface 3f is configured as a seating surface when the hub bolts 3d are fastened. The flange side surface 3f and the outer end 2f of the outer ring 2 overlap when viewed from the axial direction. A predetermined space is formed between the flange side surface 3f and the outer end 2f of the outer ring 2.

[0019] The hub wheel 3 has a base portion 3g of the wheel mounting flange 3b between the wheel mounting flange 3b (flange side surface 3f) and the inner raceway surface 3e on the outer side. The base 3g of the wheel mounting flange 3b has a radial surface 3h, an axial surface 3i, and an arc-shaped surface 3j (see Figure 2). The radial surface 3h is located on the inner diameter side of the flange side surface 3f. The radial surface 3h is composed of a straight surface that is generally parallel to the radial direction. The outer diameter end of the radial surface 3h is connected to the inner diameter end of the flange side surface 3f. The axial surface 3i is a straight surface parallel to the axial direction. The axial surface 3i is located on the outer diameter side and outer side of the outer inner raceway surface 3e, and on the inner diameter side and inner side of the radial surface 3h. The axial surface 3i is configured as the fitted portion into which the slinger fitting portion 41 of the slinger 40 fits. A predetermined space is formed between the axial surface 3i and the outer end portion 2f of the outer ring 2. The inner end of the axial surface 3i is connected to the outer end of the inner raceway surface 3e. The arc-shaped surface 3j is composed of a surface that is concave toward the inner diameter. The arc-shaped surface 3j is located on the inner diameter side of the radial surface 3h and on the outer side of the axial surface 3i. The inner end of the arc-shaped surface 3j is connected to the outer end of the axial surface 3i. The outer diameter end of the arc-shaped surface 3j is connected to the inner diameter end of the flange side surface 3f.

[0020] The inner ring 4 is press-fitted into the small-diameter stepped portion 3a of the hub ring 3 and provided on the hub ring 3. Alternatively, the inner ring 4 may be press-fitted into the small-diameter stepped portion 3a via a predetermined crimping allowance, and the hub ring 3 and the inner ring 4 may be integrated by a crimped portion formed by plastic deformation caused by crimping the inner end of the small-diameter stepped portion 3a on the hub ring 3.

[0021] The inner ring 4 has an inner raceway surface 4a on the inner side. The inner raceway surface 4a on the inner side is formed on the outer circumference of the inner ring 4 so as to face the outer raceway surface 2c on the inner side of the outer ring 2. In other words, the inner raceway surface 4a is formed on the inner side of the inner member by the inner ring 4. An annular space, the inner side opening 2a, is formed between the outer ring 2 and the inner ring 4. The inner side sealing member 9 is fitted into the inner side opening 2a and prevents foreign matter such as muddy water from entering through the inner side opening 2a. The inner side sealing member 9 is an example of a sealing device.

[0022] The inner ball row 5 is composed of multiple balls 7, which are rolling elements, held by a cage 8. The outer ball row 6 is composed of multiple balls 7, which are rolling elements, held by a cage 8. The cage 8 is formed in a substantially annular shape, and the axis of rotation of the cage 8 coincides with the axis of rotation X. The inner ball row 5 is rotatably sandwiched between the inner raceway surface 4a on the inner side 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 rotatably sandwiched between the inner raceway surface 3e on the outer side of the hub ring 3 and the outer raceway surface 2d on the outer side of the outer ring 2. In other words, the inner ball row 5 and the outer ball row 6 are rotatably housed between the respective raceway surfaces of the outer and inner members. In the wheel bearing device 1, a double-row angular contact ball bearing is composed of the outer ring 2, the hub ring 3 and the inner ring 4, the inner ball row 5, and the outer ball row 6.

[0023] [Specific configuration of the outer sealing member] As shown in Figure 2, the outer sealing member 10 comprises a core metal 20, a first elastic member 30, a slinger 40, and a second elastic member 50. The core metal 20 is fitted to the outer end 2f of the outer ring 2. The first elastic member 30 is integrally joined to the core metal 20 by vulcanization bonding or the like. The slinger 40 is configured in a substantially annular shape and is fitted to the base 3g of the wheel mounting flange 3b of the hub ring 3. The second elastic member 50 is integrally joined to the slinger 40 by vulcanization bonding or the like.

[0024] The core metal 20 is positioned such that a predetermined gap is formed between it and the slinger 40, and the core metal 20 and the slinger 40 are configured to be non-contact. The core metal 20 is configured to be substantially annular with a substantially L-shaped cross-section. The core metal 20 has a core metal fitting portion 21, an inner diameter portion 22, and a pressing surface 23. The core metal fitting portion 21, the inner diameter portion 22, and the pressing surface 23 are formed from metal members made of, for example, stainless steel.

[0025] The core fitting portion 21 of the core metal 20 is cylindrical in shape and is fitted to the outer circumferential surface near the outer end 2f of the outer ring 2. The core fitting portion 21 is configured parallel to the axial direction. The core fitting portion 21 is an example of a fitting portion. The core fitting portion 21 can also be configured to be fitted to the inner circumferential surface near the outer end 2f of the outer ring 2.

[0026] The inner diameter portion 22 of the mandrel 20 is configured in a substantially annular shape and is located on the inner diameter side of the mandrel fitting portion 21. The inner diameter portion 22 extends inward from the mandrel fitting portion 21. The outer diameter side end of the inner diameter portion 22 is connected to the outer side end of the mandrel fitting portion 21. The inner diameter portion 22 has a crank-shaped cross-section. The outer diameter side portion of the inner diameter portion 22 is configured parallel to the radial direction, the radial middle portion of the inner diameter portion 22 is configured inclined with respect to the radial direction, and the inner diameter side portion of the inner diameter portion 22 is configured parallel to the radial direction. The outer diameter side portion of the inner diameter portion 22 is located on the outer side of the inner diameter side portion of the inner diameter portion 22. The inner side surface of the outer diameter side portion of the inner diameter portion 22 is configured as a pressing surface 23. The pressing surface 23 faces the outer side end 2f of the outer ring 2. The pressing surface 23 contacts and presses against the outer end 2f of the outer ring 2. When viewed from the axial direction, the pressing surface 23 overlaps with the outer end 2f of the outer ring 2 and the flange side surface 3f of the hub ring 3.

[0027] The first elastic member 30 is made of, for example, synthetic rubber and is configured to be elastically deformable. The first elastic member 30 has a base portion 31, a seal lip 32, and a weir portion 37.

[0028] The base 31 of the first elastic member 30 is joined to the inner end face of the core fitting portion 21 of the core metal 20, the outer diameter side surface of the core fitting portion 21, the outer side surface of the inner diameter portion 22, the inner diameter end face of the inner diameter portion 22, and a part of the inner side surface of the inner diameter portion 22. The base 31 only needs to be joined to at least the outer side surface of the inner diameter portion 22 of the core metal 20.

[0029] The seal lip 32 of the first elastic member 30 prevents foreign matter such as muddy water from entering between the core metal 20 and the slinger 40. The seal lip 32 is provided on the base portion 31 and extends from the base portion 31 toward the wheel mounting flange 3b side of the hub wheel 3 or toward the core metal 20 side.

[0030] The weir portion 37 of the first elastic member 30 prevents foreign matter such as muddy water from entering between the core metal 20 and the slinger 40. The weir portion 37 is provided on the base portion 31 and extends outward from the base portion 31. The weir portion 37 protrudes outward from the outer surface of the outer end portion 2f of the outer ring 2. The weir portion 37 is positioned on the inner side of the seal lip 32. The weir portion 37 is positioned on the inner side of the hub bolts 3d of the hub ring 3. The weir portion 37 is configured to be non-contact with the hub ring 3 and is positioned so as to form a predetermined gap between it and the hub bolts 3d of the hub ring 3.

[0031] The slinger 40 has a slinger fitting portion 41, a disc portion 42, a connecting portion 43, a protruding portion 44, and an inner side end face 45, and is configured in a substantially U-shaped cross-section. The slinger fitting portion 41, the disc portion 42, the connecting portion 43, and the protruding portion 44 are formed from metal members, for example, stainless steel.

[0032] The slinger fitting portion 41 of the slinger 40 is cylindrical in shape and is fitted onto the axial surface 3i of the hub wheel 3. The slinger fitting portion 41 is configured parallel to the axial direction.

[0033] The disc portion 42 of the slinger 40 is annular in shape and is located on the outer diameter side of the slinger fitting portion 41. The disc portion 42 is configured parallel to the radial direction. The disc portion 42 faces the inner diameter portion 22 of the mandrel 20 in the axial direction.

[0034] The connecting portion 43 of the slinger 40 is positioned between the slinger fitting portion 41 and the disc portion 42. The connecting portion 43 connects the slinger fitting portion 41 and the disc portion 42 and is inclined with respect to the axial direction. The inner end of the connecting portion 43 is connected to the outer end of the slinger fitting portion 41, and the outer diameter end of the connecting portion 43 is connected to the inner diameter end of the disc portion 42.

[0035] The projection 44 of the slinger 40 is cylindrical in shape and protrudes from the outer diameter side end of the disc portion 42 toward the inner side and toward the base portion 31 of the first elastic member 30. The projection 44 is configured parallel to the axial direction. When viewed from the axial direction, the projection 44 overlaps with the inner diameter portion 22 of the mandrel 20 (the outer diameter side portion of the inner diameter portion 22), and when viewed from the radial direction, it overlaps with the seal lip 32 of the first elastic member 30. The inner side end of the projection 44 is configured as the inner side end face 45. The inner side end face 45 faces the outer side surface of the inner diameter portion 22 of the mandrel 20 (the outer side surface of the outer diameter side portion of the inner diameter portion 22).

[0036] The second elastic member 50 is made of, for example, synthetic rubber and is configured to be elastically deformable. The second elastic member 50 is integrally joined to the slinger 40 (projection 44) by vulcanization bonding or the like. The second elastic member 50 comprises a contact portion 51, an outer peripheral portion 52, and an end face portion 53. The contact portion 51 is joined to a part of the outer side surface of the disc portion 42 of the slinger 40. The outer peripheral portion 52 is joined to the outer peripheral surface of the projection 44 of the slinger 40. The end face portion 53 is joined to the inner side end face 45 of the projection 44 of the slinger 40.

[0037] The contact portion 51 of the second elastic member 50 is located between the disc portion 42 of the slinger 40 and the base portion 3g of the wheel mounting flange 3b of the hub wheel 3. The contact portion 51 has a projection 51a that protrudes outward from the outer side surface of the contact portion 51. The axial length L of the projection 51a of the contact portion 51 that protrudes outward is 0.2 mm or more and 0.3 mm or less. The axial length L of the projection 51a of the contact portion 51 is set to, for example, 0.25 mm. It is set as an overlap defined by the axial length L of the projection 51a of the contact portion 51. The contact portion 51 contacts the base portion 3g of the wheel mounting flange 3b of the hub wheel 3 with the overlap (projection 51a). That is, the disc portion 42 of the slinger 40 contacts the radial surface 3h of the hub wheel 3 (base portion 3g of the wheel mounting flange 3b) via the contact portion 51 (second elastic member 50). In this way, the disc portion 42 of the slinger 40 contacts the hub wheel 3 via the contact portion 51, preventing foreign matter such as muddy water from entering between the base portion 3g of the wheel mounting flange 3b of the hub wheel 3 and the disc portion 42 of the slinger 40.

[0038] The end face portion 53 of the second elastic member 50 faces the outer side surface of the inner diameter portion 22 of the core metal 20 (the outer side surface of the outer diameter portion of the inner diameter portion 22). The end face portion 53 is configured to be non-contact with the base portion 31 of the first elastic member 30, for example, when the vehicle is not running, when the wheel bearing device 1 is not repeatedly subjected to vibrations during vehicle operation, or when the load on the wheel bearing device 1 is relatively low and the wheel bearing device 1 is not deformed.

[0039] The seal lip 32 of the first elastic member 30 has a first seal lip 33, a second seal lip 34, and a third seal lip 35.

[0040] The first seal lip 33 of the seal lip 32 prevents foreign matter such as muddy water from entering between the core metal 20 and the slinger 40. The first seal lip 33 is provided on the base portion 31. The first seal lip 33 extends from the base portion 31 (core metal 20) toward the axial surface 3i of the hub wheel 3 and contacts the slinger fitting portion 41 of the slinger 40. In this way, the first seal lip 33 contacts the slinger fitting portion 41 of the slinger 40, which reliably prevents foreign matter such as muddy water from entering between the slinger 40 and the core metal 20. Note that the first seal lip 33 can also be configured to not contact the slinger 40.

[0041] The second seal lip 34 of the seal lip 32 prevents foreign matter such as muddy water from entering between the core metal 20 and the slinger 40. The second seal lip 34 is provided on the base portion 31 and is located on the outer diameter side of the first seal lip 33. The second seal lip 34 extends from the base portion 31 (core metal 20) toward the arc-shaped surface 3j of the hub wheel 3 and contacts the connection portion 43 of the slinger 40. In this way, by positioning the second seal lip 34 on the outer diameter side of the first seal lip 33 and contacting the connection portion 43 of the slinger 40, the entry of foreign matter such as muddy water from between the slinger 40 and the core metal 20 can be reliably prevented. Note that the second seal lip 34 can also be configured to not contact the slinger 40.

[0042] The third seal lip 35 of the seal lip 32 prevents foreign matter such as muddy water from entering between the core metal 20 and the slinger 40. The third seal lip 35 is provided on the base 31 and is located on the outer diameter side of the first seal lip 33 and the second seal lip 34. The third seal lip 35 extends from the base 31 (core metal 20) toward the radial surface 3h of the hub wheel 3. The third seal lip 35 is positioned on the outer diameter side of the projection 44 of the slinger 40 and overlaps with the projection 44 of the slinger 40 when viewed radially. The fourth seal lip 36 is configured to be non-contact with the slinger 40.

[0043] The fourth seal lip 36 of the seal lip 32 prevents foreign matter such as muddy water from entering between the core metal 20 and the slinger 40. The fourth seal lip 36 is provided on the base 31 and is located on the outer diameter side of the first seal lip 33, the second seal lip 34, and the third seal lip 35. The fourth seal lip 36 extends from the base 31 (core metal 20) toward the radial surface 3h of the hub wheel 3. The fourth seal lip 36 is configured to be non-contact with the hub bolts 3d and the radial surface 3h of the hub wheel 3. The fourth seal lip 36 is positioned on the outer diameter side of the projection 44 of the slinger 40 and overlaps with the projection 44 of the slinger 40 when viewed from the radial direction. The fourth seal lip 36 is configured to be non-contact with the slinger 40.

[0044] The protruding portion 44 of the slinger 40 is located radially between the third seal lip 35 and the fourth seal lip 36 of the first elastic member 30. The protruding portion 44 of the slinger 40 is positioned such that, viewed radially, it overlaps with the third seal lip 35 of the first elastic member 30, and a predetermined gap is formed between it and the third seal lip 35. The protruding portion 44 of the slinger 40 is positioned such that, viewed radially, it overlaps with the fourth seal lip 36 of the first elastic member 30, and a predetermined gap is formed between it and the fourth seal lip 36. The gap between the protruding portion 44 of the slinger 40 and the third seal lip 35 of the first elastic member 30, and the gap between the protruding portion 44 of the slinger 40 and the fourth seal lip 36 of the first elastic member 30, are configured as a labyrinth. By configuring the labyrinth in this way, it is possible to reliably prevent foreign matter such as muddy water from entering between the slinger 40 and the core metal 20.

[0045] The axial distance W1 between the end face 53 of the second elastic member 50 and the base 31 of the first elastic member 30 (the portion of the base 31 facing the end face 53 of the second elastic member 50) is 0.5 mm or less. The axial distance W1 between the end face 53 of the second elastic member 50 and the base 31 of the first elastic member 30 is, for example, 0.4 mm. In a typical sealing device, the slinger may move inward by up to approximately 0.7 mm due to repeated vibrations during vehicle operation of the wheel bearing device, or due to deformation of the wheel bearing device 1 caused by a relatively large load. As described above, the axial distance W1 between the end face 53 of the second elastic member 50 and the base 31 of the first elastic member 30 is 0.5 mm or less. In other words, the axial distance W1 is shorter than the maximum distance (approximately 0.7 mm) that the slinger moves when the wheel bearing device in a typical sealing device configuration is repeatedly subjected to vibrations while the vehicle is running. Therefore, when the wheel bearing device 1 is repeatedly subjected to vibrations while the vehicle is running, or when the wheel bearing device 1 is subjected to a relatively large load and deforms, the slinger 40 moves by the axial distance W1, causing the end face 53 of the second elastic member 50 and the base 31 of the first elastic member 30 to come into contact, thereby restricting the movement of the slinger 40 toward the inner side. By restricting the movement of the slinger 40 toward the inner side in this way, it is possible to suppress excessive tightening of the first elastic member 30 seal lip 32 that contacts the slinger 40 when the slinger 40 moves toward the inner side (towards the core metal 20). Therefore, it is possible to suppress an increase in rotational torque caused by the wheel bearing device 1 being repeatedly subjected to vibrations during vehicle operation, or by the wheel bearing device 1 being deformed due to a relatively large load. Furthermore, it is possible to prevent damage to the seal lip or poor contact of the seal lip with the slinger caused by the wheel bearing device 1 being repeatedly subjected to vibrations during vehicle operation, or by the wheel bearing device 1 being deformed due to a relatively large load, thereby suppressing a decrease in mud-water resistance.

[0046] It is conceivable that after the slinger 40 moves axially by W1 minutes and the end face 53 of the second elastic member 50 comes into contact with the base 31 of the first elastic member 30, the wheel bearing device 1 will no longer be subjected to vibrations during operation, or the wheel bearing device 1 will return to its original state from a deformed state, causing the slinger 40 to move outward and return to its original position. It is also conceivable that after the slinger 40 moves axially by W1 minutes and the end face 53 of the second elastic member 50 comes into contact with the base 31 of the first elastic member 30, the state in which the end face 53 of the second elastic member 50 and the base 31 of the first elastic member 30 are in contact will continue. As shown in Figure 3, repeated contact between the end face 53 of the second elastic member 50 and the base 31 of the first elastic member 30, and the continued contact between the end face 53 of the second elastic member 50 and the base 31 of the first elastic member 30, causes the portion of the base 31 of the first elastic member 30 that is in contact with the end face 53 of the second elastic member 50 to be worn away by the end face 53 of the second elastic member 50. The worn portion of the base 31 of the first elastic member 30 is formed as a recess 38. The recess 38 of the first elastic member 30 faces the end face 53 of the second elastic member 50 in the axial direction with a predetermined gap. The gap between the recess 38 of the first elastic member 30 and the end face 53 of the second elastic member 50 is formed as a labyrinth. By forming a labyrinth in this way, it is possible to reliably prevent foreign matter such as muddy water from entering between the slinger 40 and the core metal 20. Furthermore, a recess 38 may be formed in advance in the base portion 31 of the first elastic member 30 in the portion facing the end face portion 53 of the second elastic member 50 in the axial direction.

[0047] As shown in Figure 4, the distance between the end face 53 of the second elastic member 50 and the base 31 of the first elastic member 30 (the portion of the base 31 facing the end face 53 of the second elastic member 50) may be less than or equal to the overlap of the contact portion 51 of the second elastic member 50 (the axial length L of the projection 51a of the contact portion 51). In this case, the distance between the end face 53 of the second elastic member 50 and the base 31 of the first elastic member 30 (the portion of the base 31 facing the end face 53 of the second elastic member 50) is, for example, 0.1 mm.

[0048] As described above, the end face portion 53 of the second elastic member 50 and the base portion 31 of the first elastic member 30 (the portion of the base portion 31 facing the end face portion 53 of the second elastic member 50) are less than or equal to the interference fit of the contact portion 51 of the second elastic member 50 (the axial length L of the projection 51a of the contact portion 51). Therefore, even when the wheel bearing device 1 is repeatedly subjected to vibrations while the vehicle is running, or when the wheel bearing device 1 is subjected to a relatively large load and deforms, the slinger 40 moves axially by a distance W1, restricting the movement of the slinger 40 toward the inner side, and the contact portion 51 of the second elastic member 50 remains in contact with the base portion 3g of the wheel mounting flange 3b of the hub wheel 3 with an interference fit (projection 51a). Therefore, when the slinger 40 moves inward (away from the hub wheel 3), it is possible to prevent a decrease in the sealing performance between the base 3g of the wheel mounting flange 3b of the hub wheel 3 and the contact portion 51 of the second elastic member 50, thereby preventing a decrease in mud and water resistance between the base 3g of the wheel mounting flange 3b of the hub wheel 3 and the disc portion 42 of the slinger.

[0049] In this configuration, the thickness (axial length) of the portion of the base 31 of the first elastic member 30 that covers the outer diameter side portion of the inner diameter portion 22 of the core metal 20 is set to be larger than the overlap of the contact portion 51 of the second elastic member 50 (axial length L of the projection 51a of the contact portion 51). With this configuration, even if the base 31 of the first elastic member 30 is scraped by the end face portion 53 of the second elastic member 50, the outer side surface of the inner diameter portion 22 of the core metal 20 remains covered by the base 31 of the first elastic member 30, preventing the outer side surface of the inner diameter portion 22 of the core metal 20 from being exposed. Therefore, the inner diameter portion 22 of the core metal 20 remains covered by the base 31 of the first elastic member 30, preventing the core metal 20 from oxidizing or becoming easily damaged.

[0050] As shown in Figure 5, the second elastic member 50 may not have an end face portion 53, and the inner end face 45 of the projection portion 44 of the slinger 40 may be exposed facing inward. The inner end face 45 of the slinger 40 is configured to be non-contact with the base portion 31 of the first elastic member 30, for example, when the wheel is not rotating, or when the load on the wheel bearing device 1 is relatively low and the wheel bearing device 1 is not deformed. The axial distance W2 between the inner end face 45 of the slinger 40 and the base portion 31 of the first elastic member 30 (the portion of the base portion 31 facing the inner end face 45 of the slinger 40) is 0.5 mm or less.

[0051] As described above, the axial distance W2 between the inner end face 45 of the slinger 40 and the base 31 of the first elastic member 30 is 0.5 mm or less. In other words, the axial distance W2 is shorter than the maximum distance the slinger moves in a typical sealing device due to repeated vibrations of the wheel bearing device while the vehicle is running. When the wheel bearing device 1 is repeatedly subjected to vibrations of the vehicle while it is running, or when the wheel bearing device 1 is subjected to a relatively large load and deforms, the inner end face 45 of the slinger 40 and the base 31 of the first elastic member 30 come into contact when the slinger 40 moves by the axial distance W2, thereby restricting the movement of the slinger 40 toward the inner side. By restricting the movement of the slinger 40 toward the inner side in this way, it is possible to suppress excessive tightening of the first elastic member 30 seal lip 32 that contacts the slinger 40 when the slinger 40 moves toward the inner side (towards the core metal 20). Therefore, it is possible to suppress an increase in rotational torque caused by the wheel bearing device 1 being repeatedly subjected to vibrations during vehicle operation, or by the wheel bearing device 1 being deformed due to a relatively large load. Furthermore, it is possible to prevent damage to the seal lip or poor contact of the seal lip with the slinger caused by the wheel bearing device 1 being repeatedly subjected to vibrations during vehicle operation, or by the wheel bearing device 1 being deformed due to a relatively large load, thereby suppressing a decrease in mud-water resistance.

[0052] As shown in Figure 6, repeated contact occurs between the inner end face 45 of the slinger 40 and the base 31 of the first elastic member 30, and the contact between the inner end face 45 of the slinger 40 and the base 31 of the first elastic member 30 continues, causing the portion of the base 31 of the first elastic member 30 that contacts the inner end face 45 of the slinger 40 to be worn away by the inner end face 45 of the slinger 40. The worn portion of the base 31 of the first elastic member 30 is formed as a recess 38. The recess 38 of the first elastic member 30 faces the inner end face 45 of the slinger 40 in the axial direction with a predetermined gap. The gap between the recess 38 of the first elastic member 30 and the inner end face 45 of the slinger 40 is formed as a labyrinth. By forming a labyrinth in this way, it is possible to reliably prevent foreign matter such as muddy water from entering between the slinger 40 and the core metal 20. Furthermore, a recess 38 may be formed in advance in the base portion 31 of the first elastic member 30 in the portion that faces the inner end face 45 of the slinger 40 in the axial direction.

[0053] Furthermore, in this configuration, the axial distance W2 between the inner end face 45 of the slinger 40 and the base 31 of the first elastic member 30 may be less than or equal to the overlap of the contact portion 51 of the second elastic member 50 (the axial length L of the projection 51a of the contact portion 51). In this case, the axial distance W2 between the inner end face 45 of the slinger 40 and the base 31 of the first elastic member 30 is set to, for example, 0.1 mm.

[0054] As described above, the axial distance W2 between the inner end face 45 of the slinger 40 and the base 31 of the first elastic member 30 is less than or equal to the interference fit (axial length L of the projection 51a of the contact portion 51) of the second elastic member 50. Therefore, even when the wheel bearing device 1 is repeatedly subjected to vibrations while the vehicle is running, or when the wheel bearing device 1 is subjected to a relatively large load and deforms, the slinger 40 moves by an axial distance W2, restricting the movement of the slinger 40 toward the inner side, and the contact portion 51 of the second elastic member 50 remains in contact with the base 3g of the wheel mounting flange 3b of the hub wheel 3 with an interference fit (projection 51a). Therefore, when the slinger 40 moves inward (away from the hub wheel 3), it is possible to prevent a decrease in the sealing performance between the base 3g of the wheel mounting flange 3b of the hub wheel 3 and the contact portion 51 of the second elastic member 50, thereby preventing a decrease in mud and water resistance between the base 3g of the wheel mounting flange 3b of the hub wheel 3 and the disc portion 42 of the slinger.

[0055] In this configuration, the thickness (axial length) of the portion of the base 31 of the first elastic member 30 that covers the outer diameter side portion of the inner diameter portion 22 of the core metal 20 is set to be larger than the overlap of the contact portion 51 of the second elastic member 50 (axial length L of the projection 51a of the contact portion 51). With this configuration, even if the base 31 of the first elastic member 30 is scraped by the inner end face 45 of the slinger 40, the outer side surface of the inner diameter portion 22 of the core metal 20 remains covered by the base 31 of the first elastic member 30, preventing the outer side surface of the inner diameter portion 22 of the core metal 20 from being exposed. Therefore, by maintaining the state in which the inner diameter portion 22 of the core metal 20 remains covered by the base 31 of the first elastic member 30, it is possible to prevent the core metal 20 from oxidizing or becoming easily damaged due to the base 31 of the first elastic member 30 being exposed.

[0056] Although a wheel bearing device referred to as the third generation has been given as an example, the wheel bearing device according to the present invention is not limited to such a structure. For example, it may be a first-generation or second-generation structure in which a pair of inner rings are press-fitted into the small-diameter stepped portion of the hub ring, or a fourth-generation structure in which inner raceway grooves are formed on the outer circumferential surfaces of the hub ring and the constant velocity universal joint, respectively, and these are used as inner members. Furthermore, although a double-row angular contact ball bearing with a row of balls as the rolling elements has been given as an example, it is not limited to this, and a double-row tapered roller bearing with tapered rollers as the rolling elements is also acceptable.

[0057] Although embodiments of the present invention have been described above, the present invention is not limited in any way to these embodiments, but is merely illustrative. It can be implemented in various other forms without departing from the spirit of the invention, and the scope of the present invention is indicated by the claims, and further includes all modifications within the meaning and scope of equivalents as described in the claims. [Explanation of symbols]

[0058] 1. Wheel bearing device 2. Outer ring (outer member) 2a Inner side opening 2b Outer side opening 2c Inner outer raceway surface 2d Outer side outer raceway surface 2e Body mounting flange 2f Outer side end 3. Hub ring (inner member) 3a Small diameter stepped section 3b Wheel mounting flange 3c bolt hole 3D hub bolts 3e Inner raceway surface on the outer side 3g base 3h Radial surface 3i Axial plane 3j arc-shaped surface 4. Inner ring (inner member) 4a Inner side inner raceway surface 5. Inner ball row 6 Outer ball rows 7. Ball (rolling element) 8 Cage 9. Inner side sealing member (sealing device) 10. Outer side sealing member (sealing device) 20 Mandrel 21 Core fitting section 22 Inner diameter 23 Pressing surface 30 First elastic member 31 Base 32 Seal Lip 33 First Seal Lip 34 Second Seal Lip 35 Third Seal Lip 36. Fourth Seal Lip 37 Weir 38 recesses 40 Slinger 41 Slinger fitting section 42. Disc section 43 Connection part 44 Protrusion 45 Inner side end face 50 Second elastic member 51 Contact area 51a protrusion 52 Outer periphery 53 End face part W1 Axial distance between the end face of the second elastic member and the base of the first elastic member The axial distance between the inner end face of the protrusion of the W2 slinger and the base of the first elastic member. L The axial length of the projection on the outer side of the contact portion of the second elastic member (compression allowance of the second elastic member)

Claims

1. An outer member having double rows of outer raceway surfaces on its inner circumference, An inner member comprising a hub ring having a wheel mounting flange on the outer side for attaching a wheel and a small diameter stepped portion extending axially on its outer circumference, and at least one inner ring press-fitted into the small diameter stepped portion of the hub ring, having double rows of inner raceway surfaces facing the double rows of outer raceway surfaces, A double row of rolling elements is rotatably housed between the raceway surfaces of the outer member and the inner member, A wheel bearing device comprising a sealing device that closes the outer open end of the annular space formed by the outer member and the inner member, The sealing device is A core metal fitted to the outer end of the outer member, A first elastic member integrally joined to the aforementioned core metal, A slinger fitted to the base of the wheel mounting flange on the hub wheel, The slinger comprises a second elastic member joined to the slinger, The aforementioned core metal is A core metal fitting portion that is fitted to the outer end of the outer member, It has an inner diameter portion that extends inward from the core fitting portion, The first elastic member is, A base portion joined to the inner diameter portion of the core metal, It has a seal lip extending from the base toward the wheel mounting flange side, The aforementioned slinger is The second elastic member contacts the base of the wheel mounting flange, and the disc portion faces the inner diameter portion of the core metal in the axial direction, The disc portion has a projection that extends from the outer diameter side end toward the base side of the first elastic member and overlaps with the seal lip when viewed from the radial direction, The second elastic member is A contact portion is located between the disc portion of the slinger and the base of the wheel mounting flange, and contacts the base of the wheel mounting flange with an overlap, The slinger has an end face portion that is joined to the inner side end face of the protruding portion, A wheel bearing device in which the axial distance between the end face of the second elastic member and the portion of the base of the first elastic member facing the end face is 0.5 mm or less.

2. The wheel bearing device according to claim 1, wherein the axial distance between the end face of the second elastic member and the portion of the base of the first elastic member facing the end face is less than or equal to the interference fit defined by the axial length of the projection protruding outward from the contact portion of the second elastic member.

3. An outer member having double rows of outer raceway surfaces on its inner circumference, An inner member comprising a hub ring having a wheel mounting flange on the outer side for attaching a wheel and a small diameter stepped portion extending axially on its outer circumference, and at least one inner ring press-fitted into the small diameter stepped portion of the hub ring, having double rows of inner raceway surfaces facing the double rows of outer raceway surfaces, A double row of rolling elements is rotatably housed between the raceway surfaces of the outer member and the inner member, A wheel bearing device comprising a sealing device that closes the outer open end of the annular space formed by the outer member and the inner member, The sealing device is A core metal fitted to the outer end of the outer member, A first elastic member integrally joined to the aforementioned core metal, A slinger fitted to the base of the wheel mounting flange on the hub wheel, The slinger comprises a second elastic member joined to the slinger, The aforementioned core metal is A core metal fitting portion that is fitted to the outer end of the outer member, It has an inner diameter portion that extends inward from the core fitting portion, The first elastic member is, A base portion joined to the inner diameter portion of the core metal, It has a seal lip extending from the base toward the wheel mounting flange side, The aforementioned slinger is The disc portion that contacts the wheel mounting flange via the second elastic member and faces the inner diameter portion of the core metal in the axial direction, The disc portion has a projection that extends from the outer diameter side end toward the base side of the first elastic member and overlaps with the seal lip when viewed from the radial direction, The second elastic member is The slinger has a contact portion located between the disc portion and the base portion of the wheel mounting flange, which contacts the wheel mounting flange with an overlap, A wheel bearing device in which the axial distance between the inner end face of the protrusion in the slinger and the portion of the base of the first elastic member facing the end face is 0.5 mm or less.

4. The wheel bearing device according to claim 1 or claim 3, wherein the axial distance between the inner end face of the protrusion in the slinger and the portion of the base of the first elastic member facing the end face is less than or equal to the interference fit defined by the axial length of the projection protruding outward from the contact portion of the second elastic member.

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