Hub unit bearing

Abstract

To provide a hub unit bearing for easily stabilizing the position and attitude of a seal device after being assembled for blocking an opening on the axial outside of a rolling element installed space.SOLUTION: On an outer peripheral face at an end of the axial outside, an outer ring 3 has an outer ring inclined surface part 10 which is inclined in a direction where an outer diameter gets smaller as extending to the axial outside. An outer ring side seal member 20 as part of a seal device 9 includes a core metal 21 and a seal part 22. The core metal 21 has a fitting cylindrical part 23 and an outward flange part 24. On a radial outside part, the outward flange part 24 has an inclined plate part 25 expanding in a direction of extending to the axial inside as extending toward the radial outside. The seal part 22 has a gasket part 31. The gasket part 31 is joined to an axial inside face of the inclined plate part 25, and elastically pushed against the outer ring inclined surface part 10.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a hub unit bearing for rotatably supporting a wheel of an automobile relative to a suspension system. [Background technology]

[0002] An automobile wheel is rotatably supported by a hub unit bearing relative to a suspension. The hub unit bearing comprises an outer ring having a double row outer ring raceway on its inner circumferential surface, a hub having a double row inner ring raceway on its outer circumferential surface and a rotating flange protruding radially outward at a portion axially outer than the outer ring, and a plurality of rolling elements arranged to roll freely between the double row outer ring raceway and the double row inner ring raceway. The outer ring is supported and fixed to the suspension. A wheel of the wheel and a braking rotor are joined and fixed to the rotating flange of the hub.

[0003] With respect to the hub unit bearing, the axially outer side is the outer side in the width direction of the vehicle when assembled to the vehicle, and the axially inner side is the center side in the width direction of the vehicle when assembled to the vehicle.

[0004] The hub unit bearing further includes a seal device that closes an axially outer opening of the rolling element installation space that exists between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub. The seal device prevents foreign matter such as muddy water from entering the rolling element installation space from the outside through the opening, and prevents lubricating grease from leaking from the rolling element installation space to the outside.

[0005] FIG. 8 shows an installation portion of a seal device that closes the axially outer opening of the rolling element installation space in a conventional hub unit bearing described in JP 2022-48883 A.

[0006] In the hub unit bearing 100 shown in Fig. 8, a seal device 104 that closes an opening on the axially outer side (left side in Fig. 8) of a rolling element installation space 103 that exists between the inner peripheral surface of the outer ring 101 and the outer peripheral surface of the hub 102 is composed of an outer ring side seal member 104 supported by the outer ring 101. The outer ring side seal member 104 includes a core metal 105 and a seal portion 106.

[0007] The core metal 105 is configured in an overall circular ring shape, and is supported and fixed to the end portion on the outer side in the axial direction of the outer ring 101 .

[0008] The core metal 105 includes a fitting tubular portion 107 that is tightly fitted into the axially outer end of the outer ring 101, a hollow disk-shaped outward flange portion 108 that bends radially outward at a substantially right angle from the axially outer end of the fitting tubular portion 107 and extends radially outward along the axially outer end face of the outer ring 101, and a support plate portion 109 that bends radially inward from an end of the axially inner side (the right side in FIG. 8 ) of the fitting tubular portion 107. The radially outer end of the outward flange portion 108 protrudes radially outward beyond the axially outer end of the outer ring 3.

[0009] The seal portion 106 is configured in an overall annular shape, and is joined and fixed to the core metal 105. The seal portion 106 includes three seal lips 110 to 112, a dam portion 113, an eaves lip 114, and a gasket portion 118.

[0010] The three seal lips 110-112 are provided on the radially inner portion of the seal portion 106. The tips of the three seal lips 110-112 are in sliding contact with the outer circumferential surface of the hub 102 and the axially inner surface of a rotating flange 115 provided on the hub 102 over the entire circumference.

[0011] The dam portion 113 is provided on the radially outer portion of the seal portion 106, and is located radially outward from the outer peripheral surface of the axially outer end of the outer ring 101. The dam portion 113 covers the radially outer end of the outward flange portion 108, and has a base portion 116 located axially outward from the outer ring 101, and a cylindrical portion 117 extending axially inward from the base portion 116 and fitted onto the outer peripheral surface of the axially outer end of the outer ring 101 with an interference fit.

[0012] The overhanging lip 114 is disposed axially outward of the radially outer end of the outward flange portion 108, and extends axially and radially outward. The tip of the overhanging lip 114 is in close proximity to the axially inner surface of the rotating flange 115 over the entire circumference.

[0013] The gasket portion 118 covers a radially outer portion of the axially inner surface of the outward flange portion 108. The gasket portion 118 is elastically pressed against the axially outer end surface of the outer ring 101.

[0014] While the vehicle is traveling, a rotating air current is generated around the outer ring 101 due to the rotation of the wheel and the braking rotor. Muddy water splashed up from the road surface is caught in the rotating air current and circulates in the form of water droplets around the outer ring 101. When the vehicle stops and the rotating air current subsides, the water droplets that have been circulating around the outer ring together with the rotating air current fall onto the outer peripheral surface of the outer ring 101 and the axially inner surface of the rotating flange 115 at the top of the hub unit bearing 100.

[0015] Each of the dam portion 113, the eaves lip 114, and the gasket portion 118 improves the function of preventing foreign matter such as muddy water from entering the rolling element installation space 103 from the outside through an opening on the axial outside of the rolling element installation space 103.

[0016] The dam portion 113 blocks water droplets that fall onto the outer peripheral surface of the outer ring 101 and flow axially outward along the outer peripheral surface, thereby preventing the water droplets from entering between the axially outer end face of the outer ring 101 and the axially inner surface of the rotating flange 115.

[0017] The eaves lip 114 prevents muddy water splashed up from the road surface from directly entering between the axially outer end face of the outer ring 101 and the axially inner surface of the rotating flange 115.

[0018] The gasket portion 118 prevents muddy water from entering through the gap between the axially outer end face of the outer ring 101 and the axially inner side face of the outward flange portion 108 . [Prior art documents] [Patent documents]

[0019] [Patent Document 1] Patent Publication No. 2022-48883 Summary of the Invention [Problem to be solved by the invention]

[0020] The conventional structure described in JP 2022-48883 A has room for improvement in terms of stabilizing the position and posture of the outer race side seal member 104 after assembly and making it easier to properly ensure the sealing performance of the outer race side seal member 104. This point will be described below.

[0021] In the conventional structure described in JP 2022-48883 A, the mating tube portion 107 of the core wire 105 is fitted into the inner peripheral surface of the axially outer end portion of the outer ring 101 by pressing it in from the axially outer side, and the cylindrical portion 117 of the seal portion 106 is fitted into the outer peripheral surface of the axially outer end portion of the outer ring 101 by pressing it in from the axially outer side.

[0022] In the conventional structure, when the fitting tubular portion 107 of the core bar 105 is press-fitted into the inner peripheral surface of the axially outer end of the outer ring 101 by about half of its axial length, the cylindrical portion 117 of the seal portion 106 begins to be press-fitted onto the outer peripheral surface of the axially outer end of the outer ring 101. When the cylindrical portion 117 begins to be press-fitted onto the outer peripheral surface of the axially outer end of the outer ring 101, an annular space is formed on all four sides by the axially outer end face of the outer ring 101, the axially inner side surface of the outward flange portion 108 of the core bar 105, the outer peripheral surface of the fitting tubular portion 107, and the inner peripheral surface of the cylindrical portion 117.

[0023] The volume of the annular space decreases as the press-fit amount of the fitting tubular portion 107 and the cylindrical portion 117 increases. In the conventional structure, the fitting tubular portion 107 of the core bar 105 is press-fitted into the inner circumferential surface of the axially outer end of the outer ring 101, and the cylindrical portion 117 of the seal portion 106 is press-fitted into the outer circumferential surface of the axially outer end of the outer ring 101. This means that there is no escape route for the air in the annular space, and the pressure in the annular space increases as the volume of the annular space decreases.

[0024] If the pressure in the annular space increases, the press-fitting of the fitting tube portion 107 and the cylindrical portion 117 is hindered, making it difficult to assemble the outer ring side sealing member 104 to the correct position where the gasket portion 118 abuts against the axially outer end face of the outer ring 101.

[0025] If the outer ring side seal member 104 is not assembled to the correct position and a gap exists between the part of the seal portion 106 covering the axially inner surface of the outward flange portion 108 and the axially outer end face of the outer ring 101, not only will problems such as increased sliding torque or decreased sealing performance occur for at least one of the three seal lips 110-112, but there is also the possibility of problems such as relative rotation (creep) or axial movement of the outer ring side seal member 104 with respect to the outer ring 101.

[0026] Furthermore, when the fitting tubular portion 107 is press-fitted from the axially outer side into the inner peripheral surface of the axially outer end of the outer ring 101, the fitting force acting on the fitting tubular portion 107 is greater at the axially outer portion than at the axially inner portion because the rigidity of the outward flange portion 108 is high and the folded-back portion of the core metal 105 is thinned due to the effects of press working. Therefore, the amount of elastic contraction of the fitting tubular portion 107 is greater at the axially outer portion than at the axially inner portion of the fitting tubular portion 107. As a result, there is a possibility that the outward flange portion 108 will elastically deform so as to fall axially outward with its radially inner end as a fulcrum.

[0027] Furthermore, the gasket portion 118 covers only the radially outer portion of the axially inner surface of the outward flange 108. For this reason, when the outer ring side seal member 104 is assembled to the axially outer end of the outer ring 101, if the gasket portion 118 is crushed between the axially inner surface of the outward flange 108 and the axially outer end face of the outer ring 101, the radially outer portion of the outward flange 108 is pressed axially outward by the force of the gasket portion 118 attempting to elastically restore itself. This may also cause the outward flange 108 to elastically deform so as to fall axially outward with its radially inner end portion as a fulcrum.

[0028] When the outward flange portion 108 elastically deforms so as to fall axially outward with its radially inner end portion as a fulcrum, a radially contracting force acts on the tip portion of the eaves lip 114. The tip portion of the eaves lip 114 elastically deforms so as to assume a circumferentially wavy shape in an attempt to alleviate such radially contracting force.

[0029] As a result, the opposing distance between the axial inner surface of the rotating flange 115 and the tip of the eaves lip 114 changes circumferentially in a short cycle, so that the labyrinth gap cannot be set narrow enough to avoid contact between the axial inner surface of the rotating flange 115 and the tip of the eaves lip 114, which may reduce the labyrinth seal effect.

[0030] An object of the present disclosure is to provide a hub unit bearing that makes it easy to stabilize the position and posture of a seal device that closes an axially outer opening of a rolling element installation space after installation. [Means for solving the problem]

[0031] A hub unit bearing according to one aspect of the present disclosure includes an outer ring, a hub, a plurality of rolling elements, and a seal device.

[0032] The outer ring has a double row outer ring raceway on its inner circumferential surface.

[0033] The hub has a double row inner ring raceway on its outer circumferential surface, and has a rotating flange that protrudes radially outward at a portion located axially outward from the outer ring.

[0034] The plurality of rolling elements are disposed so as to roll freely between the double row outer ring raceways and the double row inner ring raceways.

[0035] The seal device closes an axially outer opening of a rolling element installation space that exists between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub.

[0036] The outer ring has, on the outer peripheral surface of the axially outer end, an outer ring inclined surface portion that is inclined in a direction such that the outer diameter becomes smaller going axially outward.

[0037] The seal device is configured to include at least an outer ring side seal member supported by the outer ring.

[0038] The outer race side seal member includes a core metal supported on an axially outer end of the outer race, and a seal portion coupled to the core metal.

[0039] The core metal has a fitting tubular portion that is tightly fitted into the inner peripheral surface of the axially outer end of the outer ring, and an outward flange portion that extends radially outward from the axially outer end of the fitting tubular portion.

[0040] The outward flange portion has, on its radially outer portion, an inclined plate portion that extends in a direction toward the axially inner side as it extends radially outward.

[0041] The seal portion has a gasket portion, and the gasket portion is joined to the axially inner surface of the inclined plate portion and is elastically pressed against the outer ring inclined surface portion.

[0042] In the hub unit bearing according to one aspect of the present disclosure, the seal portion further includes at least one seal lip, a dam portion, and an eaves lip.

[0043] The at least one seal lip is disposed on a radially inner portion of the seal portion, and a tip portion thereof is in sliding contact with a surface of the hub or a hub-side seal member fitted and fixed to the outside of the hub.

[0044] The dam portion is disposed at a radially outer portion of the seal portion and protrudes radially outward from a portion of the outer peripheral surface of the outer ring that is adjacent to the axially inner side of the outer ring inclined surface portion.

[0045] The eaves lip is disposed on a radially outer portion of the seal portion and extends axially outward, with a tip portion thereof closely facing an axially inner surface of the rotating flange.

[0046] In a hub unit bearing according to one aspect of the present disclosure, the seal portion includes a recessed portion in a portion adjacent to the radially inner side of the eaves lip.

[0047] In a hub unit bearing according to one aspect of the present disclosure, the outer ring seal member has, at a portion located radially inward of the eaves lip, an outer ring seal side surface facing axially outward, and an outer ring seal inner peripheral surface that bends axially inward from a radially inner end of the outer ring seal side surface and faces radially inward. The hub side seal member has a hub seal outer peripheral surface that faces radially opposite the outer ring seal inner peripheral surface, a hub seal side surface that bends radially inward from an axially outer end of the hub seal outer peripheral surface and faces axially outward, and a contact lip that protrudes axially outward from a radially inner end of the hub seal side surface and has a tip that contacts an axially inner surface of the rotating flange. The hub seal side surface is located axially outward of the outer ring seal side surface.

[0048] In a hub unit bearing according to one aspect of the present disclosure, the hub-side seal member can include a sliding contact ring that is fitted and fixed to the outside of the hub, and an elastic material that is coupled to the sliding contact ring.

[0049] In one embodiment of the hub unit bearing of the present disclosure, the outer ring seal side surface and the outer ring seal inner surface are provided in the seal portion, and / or the hub seal outer surface, the hub seal side surface and the contact lip are provided in the elastic material.

[0050] In one embodiment of the hub unit bearing of the present disclosure, the rotating flange has a protrusion portion on its axially inner surface that is located radially outward from the dam portion and that is axially inward from the radially outermost portion of the dam portion.

[0051] The present disclosure can be implemented by appropriately combining the configurations of each of the above-described aspects to the extent that no contradiction occurs. Effect of the Invention

[0052] According to the hub unit bearing of one aspect of the present disclosure, it is easy to stabilize the position and posture of the seal device that closes the axially outer opening of the rolling element installation space after installation, and it is easy to properly ensure the sealing performance of the seal device. [Brief description of the drawings]

[0053] [Figure 1] FIG. 1 is a cross-sectional view of a hub unit bearing according to a first embodiment of the present disclosure. [Diagram 2] FIG. 2 is an enlarged view of part A in FIG. [Diagram 3] FIG. 3 is a diagram corresponding to FIG. 2 and relating to a second example of the embodiment of the present disclosure. [Figure 4] FIG. 4 is a diagram corresponding to FIG. 2 and relating to a third example of an embodiment of the present disclosure. [Diagram 5] FIG. 5 is a view of the third example, which corresponds to an enlarged view of part B in FIG. [Figure 6]FIG. 6 is a diagram corresponding to FIG. 2 and relating to a fourth embodiment of the present disclosure. [Figure 7] FIG. 7 is a diagram corresponding to FIG. 2 and relating to a fifth example of the embodiment of the present disclosure. [Figure 8] FIG. 8 is a cross-sectional view of an installation portion of a seal device in a conventional structure of a hub unit bearing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0054] [Example 1] A hub unit bearing according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 and 2. FIG.

[0055] The hub unit bearing of the present disclosure can be applied to hub unit bearings of various structures, but in this example, a case where it is applied to a hub unit bearing for a driving wheel will be described.

[0056] With regard to the hub unit bearing 1 of this example, the axially outer side is the left side in FIG. 1, which is the outer side in the width direction of the vehicle when assembled to the vehicle, and the axially inner side is the right side in FIG. 1, which is the center side in the width direction of the vehicle when assembled to the vehicle.

[0057] The hub unit bearing 1 of this example includes an outer ring 3, a hub 6, a plurality of rolling elements 7a, 7b, and a sealing device 9.

[0058] The outer ring 3 is made of a hard metal such as medium carbon steel and has an outer peripheral surface, an inner peripheral surface, and side surfaces on both axial sides. The outer ring 3 has double-row outer ring raceways 2a, 2b on its inner peripheral surface. Furthermore, the outer ring 3 has a stationary flange 11 at an axially intermediate portion that protrudes radially outward. The stationary flange 11 is a portion used to support and fix the outer ring 3 to a knuckle of a suspension device.

[0059] The outer ring 3 has, on the outer peripheral surface at the axially outer end, an outer ring inclined surface portion 10 that is inclined in a direction such that the outer diameter decreases toward the axially outer side. In other words, the outer ring inclined surface portion 10 has a truncated cone shape. The outer ring inclined surface portion 10 is the portion against which a part of the sealing device 9 is pressed.

[0060] The inclination angle θ of the outer ring inclined surface portion 10 with respect to the axial direction of the outer ring 3 can be preferably 30° or more and 60° or less, and more preferably 40° or more and 50° or less. In this example, the inclination angle θ is about 45°.

[0061] The hub 6 is made of a hard metal such as medium carbon steel or bearing steel, has double row inner ring raceways 4a, 4b on its outer circumferential surface, and has a rotating flange 5 that protrudes radially outward from a portion located axially outward of the outer ring 3. The rotating flange 5 is a part that connects and fixes the wheel and the braking rotor that constitute the wheel.

[0062] In this example, the rotating flange 5 is configured as a hollow disk as a whole. The rotating flange 5 has a step portion 12 facing radially outward at a radially intermediate portion of its axially inner surface. In this example, the step portion 12 has a cross-sectional shape of a concave arc. A portion of the axially inner surface of the rotating flange 5 that is located radially inward from the step portion 12 has, in order from the radially outer side, a flat portion 13 and a curved portion 14. The flat portion 13 is configured by a plane perpendicular to the central axis of the hub 6. The curved portion 14 connects the flat portion 13 and a cylindrical surface portion 15 provided on the outer circumferential surface of the hub 6 at the axially intermediate portion, and has a cross-sectional shape of a concave arc.

[0063] In this example, the hub 6 is formed by combining a hub ring 16 and an inner ring 17 .

[0064] The inner ring raceway 4a on the axially outer side is provided on the outer peripheral surface of the axially middle part of the hub ring 16. The rotating flange 5 is provided on the axially outer part of the hub ring 16. The inner ring raceway 4b on the axially inner side is provided on the outer peripheral surface of the inner ring 17. The inner ring 17 is fitted and fixed to the outside of the axially inner part of the hub ring 16. As the hub unit bearing 1 in this example is for a drive wheel, the hub ring 16 has a spline hole 18 in the radial center for spline engagement with the spline shaft part that constitutes the drive shaft member.

[0065] The hub unit bearing of the present disclosure can also be applied to hub unit bearings that have a crimping portion at the axially inner end of the hub wheel that presses down on the axially inner surface of the inner ring, hub unit bearings in which the axially outer inner ring raceway is provided on the outer peripheral surface of another inner ring that is fitted onto the hub wheel, and hub unit bearings for driven wheels that do not have a spline hole in the radial center.

[0066] The rolling elements 7a, 7b are made of an iron alloy such as bearing steel or ceramics, and are arranged freely rollable between the double-row outer ring raceways 2a, 2b and the double-row inner ring raceways 4a, 4b, with multiple rolling elements held by retainers 19a, 19b.

[0067] In this example, balls are used as the rolling elements 7a, 7b, but tapered rollers can also be used as the rolling elements. In this example, the pitch circle diameter of the rolling elements 7a in the axially outer row is the same as the pitch circle diameter of the rolling elements 7b in the axially inner row. However, the hub unit bearing of the present disclosure can also be applied to a different diameter PCD type hub unit bearing in which the pitch circle diameter of the rolling elements in the axially inner row is different from the pitch circle diameter of the rolling elements in the axially outer row.

[0068] The sealing device 9 closes the opening on the axial outer side of the rolling element installation space 8 that exists between the inner peripheral surface of the outer ring 3 and the outer peripheral surface of the hub 6. This prevents foreign matter such as muddy water from entering the rolling element installation space 8 from the outside through the opening on the axial outer side of the rolling element installation space 8 and prevents the lubricating grease sealed in the rolling element installation space 8 from leaking to the outside.

[0069] The seal device 9 is configured to include at least an outer ring side seal member 20 supported by the outer ring 3.

[0070] In this example, the seal device 9 is composed only of an outer ring side seal member 20. However, when implementing the hub unit bearing of the present disclosure, the seal device can also be composed to include a hub side seal member supported by the hub, in addition to the outer ring side seal member.

[0071] The outer race side seal member 20 comprises a core metal 21 supported on the axially outer end of the outer race 3 , and a seal portion 22 joined to the core metal 21 .

[0072] The core metal 21 is formed into an annular shape by bending a metal plate such as a mild steel plate. The core metal 21 includes a fitting tubular portion 23 that is tightly fitted into the inner peripheral surface of the axially outer end of the outer ring 3, and an outward flange portion 24 that extends radially outward from the axially outer end of the fitting tubular portion 23. The outward flange portion 24 has an inclined plate portion 25 on the radially outer portion that extends axially inward as it moves radially outward.

[0073] In this example, the radially inner portion of the outward flange portion 24 is configured with a hollow, disk-shaped flat plate portion 26 that bends radially outward from the axially outer end portion of the fitting cylindrical portion 23 and extends radially outward along the axially outer end face of the outer ring 3. In this example, the axially inner surface of the flat plate portion 26 contacts the axially outer end face of the outer ring 3. However, when implementing the hub unit bearing of the present disclosure, the axially inner surface of the flat plate portion 26 and the axially outer end face of the outer ring 3 can also be opposed with an axial gap therebetween.

[0074] In this example, the inclined plate portion 25 has a truncated cone shape that inclines radially outward from the radial outer end of the flat plate portion 26 toward the axially inner side. The axially inner surface of the inclined plate portion 25 is disposed approximately parallel to the outer ring inclined surface portion 10.

[0075] In this example, the radially outer end of the inclined plate portion 25 protrudes radially outward from a portion of the outer peripheral surface of the outer ring 3 that is adjacent to the axially inner side of the outer ring inclined surface portion 10. However, it is also possible to make the radially outer end of the inclined plate portion not protrude radially outward from a portion of the outer peripheral surface of the outer ring that is adjacent to the axially inner side of the outer ring inclined surface portion.

[0076] In this example, the core metal 21 further includes a support plate portion 27 bent radially inward from an axially inner end portion of the fitting cylindrical portion 23. In this example, the support plate portion 27 is folded back radially inward in a U-shape from an axially inner end portion of the fitting cylindrical portion 23, and is further bent radially inward at a substantially right angle.

[0077] In this example, the seal portion 22 is made of an elastic material containing an elastomer such as rubber, has an overall circular shape, and is bonded to the surface of the core metal 21 by vulcanization adhesion.

[0078] The seal portion 22 has a gasket portion 31. In this example, the seal portion 22 further has at least one seal lip, a dam portion 29, and an overhanging lip 30.

[0079] In this example, the seal portion 22 has, as an optional component, a seal base 51 that covers the surface of the core metal 21. In this example, the base end of at least one seal lip and the base end of the eaves lip 30 are connected to the seal base 51, and the dam portion 29 and the gasket portion 31 are formed by a part of the seal base 51. The seal base 51 covers the radially outer portion, the outer peripheral surface, and the axially outer side surface of the axially inner surface of the outward flange portion 24, the inner peripheral surface of the fitting cylindrical portion 23, and the radially inner end portion of the axially outer side surface, the inner peripheral surface, and the axially inner side surface of the support plate portion 27.

[0080] When implementing the present disclosure, the seal base can be omitted, and the base end portion of at least one seal lip and the base end portion of the eaves lip can be directly bonded to the surface of the core metal.

[0081] At least one seal lip is disposed on the radially inner portion of the seal portion 22 , and its tip portion is in sliding contact with the surface of the hub 6 or a hub-side seal member fitted and fixed to the outside of the hub 6 .

[0082] In this embodiment, the at least one seal lip is composed of three seal lips 28a, 28b, and 28c. The tips of the three seal lips 28a, 28b, and 28c are in sliding contact with the surface of the hub 6.

[0083] The three seal lips 28a, 28b, 28c are arranged in the order of the first seal lip 28a, the second seal lip 28b, and the third seal lip 28c from the side closer to the rolling element installation space 8. The first seal lip 28a extends from a portion of the seal base 51 that covers the radially inner end of the support plate portion 27 toward the radially inner side and the axially inner side, and its tip portion is in sliding contact with the cylindrical surface portion 15 over the entire circumference. The second seal lip 28b extends from a portion of the seal base 51 that covers the radially inner end of the support plate portion 27 toward the axially outer side and the radially outer side, and its tip portion is in sliding contact with the curved surface portion 14 over the entire circumference. The third seal lip 28c extends from a portion of the seal base 51 that covers the axially inner side surface of the support plate portion 27 toward the axially outer side and the radially outer side, and its tip portion is in sliding contact with the flat surface portion 13 over the entire circumference.

[0084] The dam portion 29 is disposed at a radially outer portion of the seal portion 22 and protrudes radially outward from a portion of the outer peripheral surface of the outer ring 3 that is adjacent to the axially inner side of the outer ring inclined surface portion 10 .

[0085] The dam portion 29 has the function of blocking water droplets that fall onto the outer peripheral surface of the outer ring 3 and flow axially outward along said outer peripheral surface, thereby preventing the water droplets from entering between the axially outer end face of the outer ring 3 and the axially inner surface of the rotating flange 5.

[0086] In this example, the dam portion 29 has a substantially conical cylindrical shape and is configured by a portion of the seal base 51 that covers the radial outer end of the inclined plate portion 25 of the outward flange portion 24. In other words, the dam portion 29 is reinforced by the radial outer end of the inclined plate portion 25.

[0087] In this example, the dam portion 29 is formed by covering the radially outer end of the inclined plate portion 25, which protrudes radially outward from the portion of the outer peripheral surface of the outer ring 3 that is adjacent to the axially inner side of the outer ring inclined surface portion 10, with the seal portion 22. However, when implementing the hub unit bearing of the present disclosure, so long as the dam portion protrudes radially outward from the portion that is adjacent to the axially inner side of the outer ring inclined surface portion, the outer diameter of the radially outer end of the inclined plate portion can be the same as or smaller than the portion that is adjacent to the axially inner side of the outer ring inclined surface portion.

[0088] The eaves lip 30 is disposed on the radially outer side of the seal portion 22 and extends axially outward, with its tip portion closely facing or in sliding contact with the axially inner side surface of the rotating flange 5 .

[0089] The eaves lip 30 has the function of preventing muddy water splashed up from the road surface or water droplets falling from above from directly penetrating between the axially outer end face of the outer ring 3 and the axially inner surface of the rotating flange 5.

[0090] In this example, the base end (the axially inner end) of the eaves lip 30 is connected to a portion of the seal base 51 that covers the axially outer surface of the outward flange portion 24 of the core metal 21. More specifically, the base end of the eaves lip 30 is connected to a portion of the seal base 51 that covers the axially outer surface of the inclined plate portion 25. That is, the base end of the eaves lip 30b is arranged in a position where it overlaps with the inclined plate portion 25 in the axial direction. This ensures a larger axial distance from the core metal 21 to the tip of the eaves lip 30 compared to when the base end of the eaves lip is arranged in a position where it overlaps with the flat plate portion 26 of the outward flange portion 24 in the axial direction.

[0091] In this example, the eaves lip 30 extends radially outward as it extends axially outward. In this example, the tip end (axially outer end) of the eaves lip 30 closely faces the axially inner surface of the rotating flange 5 over the entire circumference in a state where it radially overlaps with a step portion 12 provided on the axially inner surface of the rotating flange 5.

[0092] The gasket portion 31 is joined to the axially inner surface of the inclined plate portion 25 and is elastically pressed against the outer ring inclined surface portion 10. The gasket portion 31 has a function of sealing between the axially inner surface of the inclined plate portion 25 and the outer ring inclined surface portion 10.

[0093] In this example, a portion of the seal base 51 constituting the gasket portion 31 is a portion of the seal base 51 that covers a radially intermediate portion of the axially inner surface of the inclined plate portion 25. The gasket portion 31 has, at its radially intermediate portion, an annular protrusion 32 that protrudes axially and radially inward.

[0094] The hub unit bearing 1 of this example further includes a combination seal ring 33 (see FIG. 1) that closes the axially inner opening of the rolling element installation space 8. This prevents external foreign matter from entering the rolling element installation space 8 through the axially inner opening of the rolling element installation space 8 and prevents grease from leaking from the rolling element installation space 8 to the outside.

[0095] The outer ring side seal member 20 is assembled to the axially outer end of the outer ring 3 by pressing the mating cylindrical portion 23 of the core metal 21 into the inner peripheral surface of the axially outer end of the outer ring 3 from the outside in the axial direction and elastically pressing the gasket portion 31 of the seal portion 22 against the outer ring inclined surface portion 10.

[0096] In this example, in the final stage of assembling the outer ring side seal member 20 to the axially outer end portion of the outer ring 3, the gasket portion 31 is elastically pressed against the outer ring inclined surface portion 10, and prior to that, no sealed annular space is formed between the axially outer end face of the outer ring 3, the outer peripheral surface of the fitting tubular portion 23, and the axially inner surface of the outward flange portion 24. For this reason, there is no problem that an increase in air pressure in the annular space would hinder the press-fitting operation of the fitting tubular portion 23, and the outer ring side seal member 20 can be easily assembled in the correct position.

[0097] This effectively prevents problems with the seal lips 28a, 28b, 28c, such as an increase in sliding torque or a decrease in sealing performance, and prevents the outer race side seal member 20 from rotating (creeping) relative to the outer race 3 or moving in the axial direction. That is to say, in this example, it is easy to stabilize the position and attitude of the outer race side seal member 20 after assembly, and it is easy to properly ensure the sealing performance of the outer race side seal member 20.

[0098] In this example, as in the conventional structure, when the fitting tubular portion 23 is press-fitted into the inner peripheral surface of the axially outer end of the outer ring 3 from the axially outer side, the fitting force acting on the fitting tubular portion 23 is greater in the axially outer portion than in the axially inner portion. However, in this example, the fitting force acting on the axially outer portion of the fitting tubular portion 23 is supported by the outer ring inclined surface portion 10 via the gasket portion 31, so that the amount of elastic diameter reduction of the fitting tubular portion 23 can be suppressed from being greater in the axially outer portion of the fitting tubular portion 23 than in the axially inner portion. Therefore, it is possible to suppress the elastic deformation of the outward flange portion 24 so that it falls axially outward from the radially inner end portion as a starting point. This suppresses the force in the diameter reduction direction acting on the tip portion of the eaves lip 30, and suppresses the elastic deformation of the tip portion of the eaves lip 30 into a circumferentially wavy shape.

[0099] In addition, in this example, when the outer ring side seal member 20 is assembled to the axially outer end of the outer ring 3, the gasket portion 31 is crushed between the axially inner surface of the inclined plate portion 25 provided on the radially outer portion of the outward flange portion 24 and the outer ring inclined surface portion 10. As a result, the outward flange portion 24 may elastically deform in a direction in which the inclined plate portion 25 faces axially outward and radially outward with its radially inner end as a fulcrum. However, the degree to which the outward flange portion 24 elastically deforms so as to fall axially outward with the radially inner end as a fulcrum is smaller than that of the conventional structure described in JP 2022-48883 A, so that the degree to which the tip portion of the eaves lip 30 is reduced in diameter due to this elastic deformation is smaller than that of the conventional structure. For this reason, it is possible to suppress elastic deformation of the tip portion of the eaves lip 30 so that it has a circumferentially wavy shape.

[0100] This prevents large gaps from occurring at multiple circumferential locations in the opposing portion between the axially inner surface of the rotating flange 5 and the tip end of the eaves lip 30, and makes it easier to set the labyrinth gap narrower and ensure a labyrinth seal effect between the axially inner surface of the rotating flange 5 and the tip end of the eaves lip 30. That is, in this respect as well, in this example, it is easier to stabilize the position and posture of the outer ring side seal member 20 after assembly, and it is easier to ensure appropriate sealing performance of the outer ring side seal member 20.

[0101] In this example, the base end of the eaves lip 30 is positioned so as to overlap the inclined plate portion 25 in the axial direction, thereby ensuring a large axial distance from the core metal 21 to the tip end of the eaves lip 30. This makes it possible to further suppress the elastic deformation of the tip end of the eaves lip 30 into a circumferentially wavy shape as described above.

[0102] In this example, the gasket portion 31 is pressed firmly against the outer ring inclined surface portion 10 by the fitting force of the fitting tube portion 23 of the core metal 21, thereby making it easier to ensure sealing performance between the axial inner surface of the inclined plate portion 25 and the outer ring inclined surface portion 10.

[0103] In addition, since the axially inner surface of the inclined plate portion 25 and the outer ring inclined surface portion 10 are each inclined surfaces, air can circulate until the gasket portion 31 comes into close contact with the outer ring inclined surface portion 10. Therefore, unlike the conventional structure described in JP 2022-48883 A, an annular space with no escape route for air is not formed, and the gasket portion 31 can be easily brought into close contact with the outer ring inclined surface portion 10.

[0104] [Example 2] A hub unit bearing according to a second embodiment of the present disclosure will be described with reference to FIG.

[0105] In the present example, in the seal device 9a, the seal portion 22a constituting the outer race side seal member 20a has a recessed portion 34 in a portion adjacent to the radially inner side of the eaves lip 30a.

[0106] In this example, the material-removing portion 34 is formed around the entire circumference of the radially outer end of the portion of the seal base 51a that covers the axially outer surface of the flat portion 26 of the core wire 21, and is constituted by a recess having an approximately triangular cross-sectional shape.

[0107] Due to the presence of the recessed portion 34, the rigidity of the root portion of the eaves lip 30a is lower than that of the first example. Therefore, when the outward flange portion 24 elastically deforms so as to fall axially outward with the radially inner end as a fulcrum, the root portion of the eaves lip 30a is more likely to elastically deform, and the force in the radial contraction direction acting on the tip portion of the eaves lip 30a can be alleviated. Therefore, the tip portion of the eaves lip 30a is further prevented from elastically deforming into a circumferentially wavy shape, and the labyrinth gap between the axially inner surface of the rotating flange 5 and the tip portion of the eaves lip 30a can be set narrower, improving the labyrinth seal effect.

[0108] In this example, among the intrusion paths for foreign matter from the external space to the rolling element installation space 8 that exist between the rotating flange 5 and the outer ring side seal member 20a, the volume of the portion adjacent to the radially inward side of the labyrinth seal portion between the axially inner surface of the rotating flange 5 and the tip end of the eaves lip 30a is made larger due to the presence of the reduced thickness portion 34, so that the amount of foreign matter that can accumulate in the portion adjacent to the radially inner side of the labyrinth seal portion can be increased accordingly, and the force of the intrusion of foreign matter can be reduced. Therefore, in this respect as well, the labyrinth seal effect between the axially inner surface of the rotating flange 5 and the tip end of the eaves lip 30a can be improved. The other configurations and effects are the same as those of the first example.

[0109] [Example 3] A hub unit bearing according to a third embodiment of the present disclosure will be described with reference to FIGS.

[0110] In this example, the seal device 9b includes a hub side seal member 35 fitted and fixed to the outside of the hub 6, in addition to the outer race side seal member 20b.

[0111] In this example, the outer ring side seal member 20b has, at a portion located radially inward of the eaves lip 30, an outer ring seal side surface 36 facing axially outward, and an outer ring seal inner surface 37 that bends axially inward from the radially inner end of the outer ring seal side surface 36 and faces radially inward.

[0112] In this example, the hub side seal member 35 has a hub seal outer surface 38 that radially faces the outer ring seal inner surface 37, a hub seal side surface 39 that bends radially inward from the axially outer end of the hub seal outer surface 38 and faces axially outward, and a contact lip 40 that protrudes axially outward from the radially inner end of the hub seal side surface 39 and has a tip that contacts the axially inner surface of the rotating flange 5.

[0113] In this example, the hub seal side surface 39 is disposed axially outboard of the outer ring seal side surface 36 .

[0114] More specifically, in this example, in outer ring side seal member 20b, outer ring seal side surface 36 and outer ring seal inner circumferential surface 37 are defined by the surface of seal base 51b that constitutes seal portion 22b. However, when implementing the hub unit bearing of the present disclosure, the outer ring seal side surface and / or the outer ring seal inner circumferential surface can also be defined by the surface of the core metal.

[0115] In this example, in the core metal 21a, the support plate portion 27a is bent radially inward from the axially inner end of the fitting tubular portion 23 and extends radially inward. The outer ring seal side surface 36 is formed by the axially outer surface of the seal base 51b, which is a portion that covers the axially outer surface of the flat plate portion 26. The outer ring seal inner circumferential surface 37 is formed by the inner circumferential surface of the seal base 51b, which is a portion that covers the inner circumferential surface of the fitting tubular portion 23. When implementing the present disclosure, the outer ring seal side surface can be formed by the axially outer surface of the flat plate portion 26 that is not covered by the seal base, and the outer ring seal inner circumferential surface can be formed by the inner circumferential surface of the fitting tubular portion 23 that is not covered by the seal base.

[0116] In this example, the inner peripheral surface 37 of the outer ring seal is configured as a tapered surface whose diameter increases toward the outside in the axial direction.

[0117] In this example, the seal portion 22b has two seal lips 28a, 28b.

[0118] In this example, the hub side seal member 35 includes a sliding contact ring 41 that is fixedly fitted onto the outside of the hub 6, and an elastic member 42 that is connected to the sliding contact ring 41.

[0119] In this example, the hub seal outer peripheral surface 38 and the hub seal side surface 39 are formed by the surface of the elastic material 42. However, when implementing the hub unit bearing of the present disclosure, the hub seal outer peripheral surface and / or the hub seal side surface can also be formed by the surface of the sliding ring.

[0120] In this example, the sliding ring 41 is made of a metal plate having rust-resistant properties such as a stainless steel plate, and has a cylindrical inner tube portion 43 that is externally fitted by an interference fit onto the cylindrical surface portion 15 provided on the outer circumferential surface of the axial middle portion of the hub 6, a side plate portion 44 that bends radially outward from the axial outer end of the inner tube portion 43 and extends radially outward, and a cylindrical outer tube portion 45 that bends axially inward from the radial outer end of the side plate portion 44, extends axially inward, and is positioned radially inside the mating tube portion 23.

[0121] In this example, the side plate portion 44 is composed of a conical cylindrical inclined plate portion 46 that bends radially outward from the axially outer end of the inner cylindrical portion 43 and extends radially and axially outward, and a hollow, disc-shaped flat plate portion 47 that extends radially outward from the radially outer end of the inclined plate portion 46.

[0122] In this example, the tip end of the first seal lip 28a is in sliding contact with the outer circumferential surface of the inner cylindrical portion 43 over the entire circumference. The tip end of the second seal lip 28b is in sliding contact with or closely faces the axially inner surface of the inclined plate portion 46 or the flat plate portion 47 over the entire circumference.

[0123] Here, although the surface of the metal plate such as a stainless steel plate from which the sliding ring 41 is made has fine streaks formed in the longitudinal direction of the metal plate by rolling, the surface roughness of the sliding ring 41 obtained by bending the metal plate is good. In particular, the axially facing surface of the sliding ring 41 (including the axially inner surface of the inclined plate portion 46) does not have logarithmic spiral streaks that are inevitably formed when grinding is performed using a shaped grindstone. Therefore, in this example, it is possible to effectively prevent an increase in frictional resistance and the generation of abnormal noise due to the tip of the second seal lip 28b sticking to the axially inner surface of the inclined plate portion 46.

[0124] In this example, the elastic member 42 is made of an elastic material containing an elastomer such as rubber, has an overall annular shape, and is bonded to the surface of the sliding ring 41 by vulcanization adhesion. In this example, the elastic member 42 has an elastic base 52, and the base end of the contact lip 40 is connected to the elastic base 52. The elastic base 52 covers, among the surfaces of the sliding ring 41, the axially outer side surface of the flat plate portion 47, the outer peripheral surface, the axially inner end surface, and the inner peripheral surface of the outer circumferential tube portion 45.

[0125] The hub seal outer peripheral surface 38 is formed by the outer peripheral surface of the elastic base 52, that part of the elastic base 52 that covers the outer peripheral surface of the outer peripheral tubular portion 45. The hub seal outer peripheral surface 38 is formed by a tapered surface with the axially outer side being the larger diameter side. The hub seal side surface 39 is formed by the axially outer side surface of the elastic base 52, that part of the elastic base 52 that covers the axially outer side surface of the flat plate portion 47. When implementing this disclosure, the hub seal outer peripheral surface can be formed by the outer peripheral surface of the outer peripheral tubular portion 45 that is not covered by the elastic base, or the hub seal side surface can be formed by the axially outer side surface of the flat plate portion 47 that is not covered by the elastic base.

[0126] The hub side seal member 35 further has a hub seal inner peripheral surface 48 on the inner peripheral surface of the portion of the elastic base portion 52 that covers the inner peripheral surface of the outer cylindrical portion 45. The hub seal inner peripheral surface 48 is configured as a tapered surface whose axially inner side is the larger diameter side.

[0127] The contact lip 40 has a function of providing a seal between the rotating flange 5 and the sliding contact ring 41 .

[0128] In this example, the contact lip 40 is provided on the elastic material 42. A base end (an axially inner end) of the contact lip 40 is connected to a radially inner end of a portion of the elastic base 52 that covers the flat plate portion 47. The contact lip 40 extends radially outward as it moves axially outward, and its tip is in sliding contact with a flat portion 13 provided on the axially inner surface of the rotating flange 5 over its entire circumference.

[0129] A groove 49 opening radially outward is formed around the entire periphery in an area surrounded on three sides by the axially inner surface of the rotating flange 5, the hub seal side surface 39, and the outer circumferential surface of the contact lip 40.

[0130] Some of the muddy water adhering to the axial inner surface of the rotating flange 5 may enter the space between the outer ring side seal member 20b and the hub side seal member 35 in the hub unit bearing 1 from the area between the axial inner surface of the rotating flange 5 and the tip of the eaves lip 30.

[0131] When the muddy water reaches the portion adjacent to the radial outside of the second seal lip 28b, it is guided by the outer circumferential surface of the second seal lip 28b by the action of gravity and moves circumferentially to the vertically lower side. The muddy water that has moved to the vertically lower side is guided downward along the hub seal inner circumferential surface 48 and the outer ring seal inner circumferential surface 37, which are tapered surfaces, as indicated by dashed arrow α in the lower part of the hub unit bearing 1 (see FIG. 5), and is further discharged into the external space through the portion located between the axially inner surface of the rotating flange 5 and the outer ring seal side surface 36, and the portion between the axially inner surface of the rotating flange 5 and the tip of the eaves lip 30.

[0132] Furthermore, as indicated by dashed arrow β, muddy water that moves downward along the axially inner surface of the rotating flange 5 and enters the recessed groove 49 at the upper part of the hub unit bearing 1 (see FIG. 4) is guided by the outer circumferential surface of the contact lip 40 and moves circumferentially to the vertically lower side. The muddy water that has moved to the vertically lower side falls through the radially outer opening of the recessed groove 49 at the lower part of the hub unit bearing 1 (see FIG. 5) as indicated by dashed arrow γ, and is then discharged into the external space through the portion between the axially inner surface of the rotating flange 5 and the tip of the eaves lip 30.

[0133] Here, if the hub seal side surface 39 were positioned axially more inward than the outer ring seal side surface 36, some of the muddy water falling downward through the radially outer opening of the recessed groove 49, as indicated by the dashed arrow β, would adhere to the lower part of the axially outer part of the outer ring seal inner circumferential surface 37. The adhered muddy water would be collected by the action of gravity at the lower end of the outer ring seal inner circumferential surface 37, and mud could accumulate at the lower end.

[0134] If mud accumulates on the lower end of the inner circumferential surface 37 of the outer ring seal, the muddy water indicated by the dashed arrow α may not be drained smoothly. Furthermore, the muddy water accumulated on the lower end of the inner circumferential surface 37 of the outer ring seal may be stirred up by the rotating hub side seal member 35 and pass through the seal provided by the contact lip 40.

[0135] In contrast, in this example, the hub seal side surface 39 is positioned axially outboard of the outer ring seal side surface 36, so muddy water falling through the radially outer opening of the recessed groove 49 as shown by the dashed arrow γ can be prevented from adhering to the lower part of the axially outer part of the outer ring seal inner circumferential surface 37. This allows smooth drainage of muddy water as shown by the dashed arrow α. Also, mud can be effectively prevented from passing through the seal portion formed by the contact lip 40.

[0136] [Example 4] A hub unit bearing according to a fourth embodiment of the present disclosure will be described with reference to FIG.

[0137] In this example, the rotating flange 5a has a protrusion portion 50 on its axially inner surface that is located radially outward from the dam portion 29 and that is axially inward from the radially outermost portion of the dam portion 29 (hereinafter referred to as the outermost diameter portion P).

[0138] More specifically, in this example, the protruding portion 50 is provided on the radially outer portion of the axially inner surface of the rotating flange 5a, and is formed by a flat surface perpendicular to the axial direction.

[0139] In this example, the axially inner surface of the rotating flange 5a has a connecting surface portion 53 that connects the radially outer end of the flat portion 13a and the radially inner end of the protruding portion 50. The connecting surface portion 53 is configured of a conical cylindrical surface that is inclined axially inward as it extends radially outward.

[0140] In this example, the radial outer end of the planar portion 13a is positioned at approximately the same radial position as the tip of the eaves lip 30, and the tip of the eaves lip 30 is closely opposed to the radial inner end of the connection surface portion 53.

[0141] In this example, the outermost diameter portion P of the dam portion 29 is formed by a corner portion that exists at the connection portion between the axially outer side surface and the radially outer end surface of the dam portion 29.

[0142] When implementing the present disclosure, the amount of axial inward protrusion L of the protrusion portion 50 relative to the outermost diameter portion P of the dam portion 29 can be preferably 1 mm or more and 5 mm or less, and more preferably 2 mm or more and 4 mm or less.

[0143] In this example, the overhanging portion 50 is disposed axially inward of the portion of the dam portion 29 that is located most axially inward.

[0144] In this example, the overhanging portion 50 is disposed axially inward of the outermost diameter portion P of the dam portion 29 in a portion located radially outward of the dam portion 29. This makes it possible to prevent muddy water that adheres to the overhanging portion 50 and falls from its radially inner end portion above the installation location of the sealing device 9 from adhering to a portion of the radially outer end portion of the dam portion 29 that is located axially outward of the outermost diameter portion P. This makes it possible to improve the waterproof performance of the opening on the axially outer side of the rolling element installation space 8.

[0145] In particular, in this example, since the overhanging portion 50 is positioned axially more inward than the axially most inner portion of the dam portion 29, muddy water that adheres to the overhanging portion 50 and falls from its radially inner end portion can be effectively prevented from adhering to the portion of the radially outer end portion of the dam portion 29 that is axially more outer than the outermost diameter portion P. The other configurations and effects are similar to those of the first example.

[0146] [Example 5] A hub unit bearing according to a fifth embodiment of the present disclosure will be described with reference to FIG.

[0147] This example is an example in which the structure of the axially inner surface of the rotating flange 5a of the fourth example is applied to the structure of the third example. For the same reason as the fourth example, this example also improves the waterproof performance of the opening on the axially outer side of the rolling element installation space 8.

[0148] The hub unit bearing of the present disclosure can be implemented by appropriately combining the structures of the respective embodiments described above within a range that does not cause any contradiction.

[0149] When implementing the hub unit bearing of the present disclosure, it is essential that the seal portion of the outer ring side seal member has a gasket portion, but other configurations of the seal portion can be determined arbitrarily. [Explanation of symbols]

[0150] 1 Hub unit bearing 2a, 2b Outer raceway 3 Outer ring 4a, 4b Inner raceway 5, 5a Rotating flange 6 Hub 7a, 7b rolling elements 8 Rolling element installation space 9, 9a, 9b Sealing device 10 Outer ring inclined surface section 11 Stationary flange 12, 12a Stepped section 13, 13a flat part 14 Curved section 15 Cylindrical surface part 16 Hub wheel 17 Inner Circle 18 Spline hole 19a, 19b retainer 20, 20a, 20b Outer ring side seal member 21, 21a Core metal 22, 22a, 22b Seal part 23 Fitting cylinder part 24 Outward flange 25 Inclined plate section 26 Flat plate part 27, 27a Support plate part 28a, 28b, 28c Seal lip 29 Weir 30, 30a visor lip 31 Gasket part 32 Annular protrusion 33 Combination Seal Ring 34 Meat Stealing Department 35 Hub side seal material 36 Outer ring seal side 37 Inner surface of outer ring seal 38 Hub seal outer surface 39 Hub seal side 40 Contact Lip 41 Sliding ring 42 Elastic material 43 Inner cylindrical part 44 Side plate part 45 Outer cylindrical part 46 Inclined plate section 47 Flat plate part 48 Hub seal inner surface 49 Groove 50 Overhang 51, 51a, 51b Seal base 52 Elastic base 53 Connection surface 100 Hub unit bearing 101 Outer ring 102 Hub 103 Rolling element installation space 104 Outer ring side seal member 105 Core 106 Seal part 107 Fitting cylinder part 108 Outward flange 109 Support plate part 110 Seal lip 111 Seal lip 112 Seal lip 113 Weir 114 Eaves lip 115 Rotating flange 116 Base 117 Cylindrical part 118 Gasket part

Claims

1. an outer ring having a double row outer ring raceway on an inner circumferential surface; a hub having a double row inner ring raceway on an outer peripheral surface thereof and a rotating flange protruding radially outward at a portion located axially outwardly of the outer ring; a plurality of rolling elements disposed between the double row outer ring raceways and the double row inner ring raceways so as to be freely rollable; a seal device that closes an axially outer opening of a rolling element installation space that exists between an inner peripheral surface of the outer ring and an outer peripheral surface of the hub; Equipped with the outer ring has, on an outer peripheral surface at an axially outer end portion, an outer ring inclined surface portion that is inclined in a direction such that an outer diameter becomes smaller toward the outside in the axial direction, the seal device is configured to include at least an outer ring side seal member supported by the outer ring, the outer race side seal member includes a core metal supported on an axially outer end portion of the outer race, and a seal portion coupled to the core metal, the core metal has a fitting tubular portion that is tightly fitted onto an inner circumferential surface of an axially outer end portion of the outer ring, and an outward flange portion that extends radially outward from the axially outer end portion of the fitting tubular portion, The outward flange portion has an inclined plate portion at a radially outer portion thereof, the inclined plate portion extending in a direction toward the axially inner side as it extends radially outward, The seal portion has a gasket portion, and the gasket portion is joined to an axially inner surface of the inclined plate portion and elastically pressed against the outer ring inclined surface portion. Hub unit bearing.

2. The seal portion further includes at least one seal lip, a dam portion, and an eaves lip, the at least one seal lip is disposed on a radially inner portion of the seal portion, and a tip portion thereof is in sliding contact with a surface of the hub or a hub-side seal member fitted and fixed to the outside of the hub, the dam portion is disposed at a radially outer portion of the seal portion and protrudes radially outward beyond a portion of an outer peripheral surface of the outer ring that is adjacent to an axially inner side of the outer ring inclined surface portion, the eaves lip is disposed on a radially outer portion of the seal portion, extends axially outward, and has a tip portion closely facing an axially inner surface of the rotating flange; The hub unit bearing according to claim 1 .

3. 3. The hub unit bearing according to claim 2, wherein the seal portion is provided with a recessed portion in a portion adjacent to the radially inner side of the eaves lip.

4. the outer ring side seal member has, at a portion located radially inward of the eaves lip, an outer ring seal side surface facing axially outward, and an outer ring seal inner circumferential surface bent axially inward from a radially inner end of the outer ring seal side surface and facing radially inward, the hub-side seal member has a hub seal outer peripheral surface radially opposed to the outer ring seal inner peripheral surface, a hub seal side surface that bends radially inward from an axially outer end portion of the hub seal outer peripheral surface and faces axially outward, and a contact lip that protrudes axially outward from a radially inner end portion of the hub seal side surface, the tip portion of which comes into contact with the axially inner surface of the rotating flange, The hub seal side surface is disposed axially outwardly of the outer ring seal side surface. The hub unit bearing according to claim 2 .

5. 3. The hub unit bearing according to claim 2, wherein the rotating flange has an axially inner surface, at a portion thereof that is radially outer than the dam portion, and a protrusion portion that is axially inner than a portion of the dam portion that is located most radially outward.

Images