JP2014052070A - Bearing unit for supporting wheel - Google Patents

Abstract

A structure capable of sufficiently securing a sealing performance between a hub body and a slinger even when the tightening margin of a slinger seal member with respect to an inner surface of a rotation side flange is reduced.
A sealing member for a slinger is provided with a gasket portion fixed to an outer surface of a side plate portion of the slinger and a flange portion disposed radially outward from the gasket portion. The gasket portion 36 is elastically brought into contact with a radially inner portion of the inner surface of the rotation side flange 9a with respect to the step portion 24. Further, the front end portion of the flange portion 35 is made to face and oppose the radially outer portion of the inner surface of the rotation-side flange 9a more than the step portion 24, and the front end portion of the flange portion 35 and the step portion 24. Are superimposed in the radial direction. By adopting such a configuration, the above problem is solved.
[Selection] Figure 1

Description

  The present invention relates to an improvement of a wheel support bearing unit for rotatably supporting a vehicle wheel with respect to a suspension device. Specifically, it realizes a structure capable of reducing the weight of the hub that rotates with the wheel while ensuring the sealing performance of the sealing device that closes the axially outer end opening of the internal space where a plurality of rolling elements are installed. .

  2. Description of the Related Art Conventionally, wheel support bearing units having various structures have been used to rotatably support automobile wheels with respect to a suspension device. 9 to 10 show one described in Patent Document 1 as an example of the conventional structure of such a wheel-supporting bearing unit. This wheel support bearing unit is configured such that a hub 2 is rotatably supported on a radially inner side of an outer ring 1 via a plurality of rolling elements 3 and 3.

  Of these, the outer ring 1 has a stationary-side flange 4 for supporting and fixing to the suspension device on the outer peripheral surface, and double-row outer ring raceways 5a and 5b on the inner peripheral surface. The hub 2 is formed by coupling and fixing a hub body 6 and an inner ring 7 and has double-row inner ring raceways 8a and 8b on the outer peripheral surface. Further, a plurality of rolling elements 3, 3 are provided between the outer ring raceways 5a, 5b and the inner ring raceways 8a, 8b, respectively, so as to be freely rollable in both rows. A rotation side flange 9 for supporting and fixing a wheel is provided at a portion of the outer peripheral surface of the hub body 6 near the outer end in the axial direction and protruding from the opening in the outer end of the outer ring 1 in the axial direction. . Note that “inside” in the axial direction means the right side of FIGS. 9 to 10, which is the center side in the width direction of the vehicle in the assembled state to the vehicle. Similarly, “outside” refers to the left side of FIGS. 9 to 10, which is the outer side in the width direction of the vehicle when assembled to the vehicle.

  Further, an axial outer end opening of a cylindrical inner space 10 in which the respective rolling elements 3 and 3 are installed, which exists between the inner peripheral surface of the outer ring 1 and the outer peripheral surface of the hub 2, is sealed with a sealing device 11. It is blocked by. At the same time, the axially inner end opening of the outer ring 1 is closed by a cover 12 made of a metal plate. The sealing device 11 and the cover 12 prevent foreign matter such as dust, rainwater, and muddy water from entering the internal space 10 from entering the internal space 10, and the grease sealed in the internal space 10 is Prevents leakage into space.

Further, as shown in detail in FIG. 10, the sealing device 11 includes a slinger 13, a seal ring 14, and a slinger seal member 15.
Of these, the slinger 13 is formed in an annular shape by a corrosion-resistant metal plate such as a stainless steel plate, and is radially outward from the fitting cylinder 16 and the axial outer edge of the fitting cylinder 16. A side plate portion 17 provided in a bent state, and a flange-like cylindrical portion 18 provided in a state bent from the outer peripheral edge of the side plate portion 17 inward in the axial direction. Of these, the fitting cylinder portion 16 is externally fitted to a portion of the outer peripheral surface of the hub body 6 adjacent to the axially inner side of the rotation side flange 9, and the outer side surface of the side plate portion 17 is It is made to contact the inner surface of the rotation side flange 9. Further, in this state, the inner peripheral surface of the front half of the bowl-shaped cylindrical portion 18 is opposed to the outer peripheral surface of the outer end of the outer ring 1 in the axial direction, and the portion between the two peripheral surfaces is used as a labyrinth seal portion. Yes.

  The slinger sealing member 15 is formed in an annular shape by an elastic material such as rubber. It is fixed to the recessed part). Then, the outer surface of the slinger seal member 15 is brought into elastic contact with the inner surface of the rotation side flange 9 over the entire circumference, so that the surface between the surface of the slinger 13 and the surface of the hub body 6 is interposed. The outer end of the gap in the radial direction is sealed by the sealing member 15 for slinger.

  The seal ring 14 includes an annular core 19 fitted and fixed to the outer end in the axial direction of the outer ring 1, and an annular made of an elastic material such as rubber reinforced by the core 19. And a seal ring seal member 20. The seal ring seal member 20 has three seal lips 21a, 21b, and 21c. The tip edge of one seal lip 21a closest to the internal space 10 is connected to the fitting cylinder. The tip edges of the remaining two seal lips 21b and 21c are in sliding contact with the inner surface of the side plate portion 17 over the entire circumference on the outer peripheral surface of the portion 16.

  In the case of the conventional structure having the above-described configuration, the sealing device 11 uses the surface of the slinger 13 made of a metal plate having corrosion resistance as a mating surface for slidingly contacting the tip edges of the seal lips 21a, 21b, 21c. Adopted. For this reason, compared with the case where the surface of the hub body 6 made of carbon steel, which is relatively susceptible to rust, is adopted as the mating surface, the deterioration of the properties of the mating surface (deterioration of the surface roughness) can be suppressed. Accordingly, the life of the sealing performance by the seal lips 21a, 21b, 21c can be extended by that much. A flange-shaped cylindrical portion 18 constituting the slinger 13 is disposed at a position that closes a radially outer end opening at a portion between the axial outer end surface of the outer ring 1 and the inner side surface of the rotating flange 9. Moreover, a portion between the inner circumferential surface of the front half of the bowl-shaped cylinder portion 18 and the outer circumferential surface of the outer ring 1 in the axial direction is a labyrinth seal portion. For this reason, rainwater and muddy water splashed from the road surface can be prevented from directly hitting the seal ring 14 and can hardly enter the installation portion of the seal ring 14. Therefore, the sealing performance by the sealing device 11 can be increased by that much.

  Further, the radially outer end of the gap existing between the surface of the slinger 13 and the surface of the hub body 6 is sealed by the slinger seal member 15. For this reason, the foreign matter existing in the external space can be prevented from entering the internal space 10 through the gap, and the grease sealed in the internal space 10 can be prevented from leaking to the external space. Furthermore, since it is possible to prevent water from entering the gap, even when the slinger 13 is made of a stainless steel plate, the material of the slinger 13 (stainless steel) and the material of the hub body 6 (carbon steel) It is possible to prevent the occurrence of electrolytic corrosion due to the standard electrode potential difference between them (corrosion of the surface of the hub body 6 made of carbon steel having a low potential).

  However, the above-described conventional structure still has room for improvement. That is, in the case of the conventional structure described above, a road surface reaction force acts on the rotation-side flange 9 through wheels when the vehicle is traveling. As a result, the rotation-side flange 9 may be elastically inclined with respect to a virtual plane orthogonal to the central axis of the hub body 6 starting from its inner diameter side end. When such an inclination occurs, the contact pressure between the inner surface of the rotating flange 9 and the slinger seal member 15 is reduced in a part in the circumferential direction, and the sealing performance of the part is reduced. Therefore, even in such a case, it is necessary to increase the tightening margin of the slinger seal member 15 with respect to the inner surface of the rotation side flange 9 in order to prevent the sealing performance of the portion from being insufficient. . However, when the tightening margin is increased, the elastic portion of the slinger seal member 15 causes the portion closer to the outer diameter of the side plate portion 17 constituting the slinger 13 to be strongly pressed toward the inner side in the axial direction. As a result, the inner side surface of the side plate portion 17 is elastically distorted, and it may be difficult to sufficiently secure the sealing performance by the seal lips 21b and 21c having the tip edge slidingly contacted with the inner side surface. There is sex. Alternatively, the slinger 13 may move inward in the axial direction against the frictional force acting on the fitting portion between the slinger 13 and the hub body 6 due to the elasticity. When moved, the sliding contact pressure of the tip edges of the two seal lips 21b and 21c with respect to the inner surface of the side plate portion 17 increases, and the dynamic torque of the wheel supporting bearing unit increases accordingly. .

JP 2005-291485 A

  In view of the circumstances as described above, the present invention can ensure the sealing performance between the hub and the slinger even when the tightening margin of the slinger seal member with respect to the inner surface of the rotation side flange is reduced in a properly assembled state. It was invented to realize the structure.

The wheel support bearing unit of the present invention includes an outer ring, a hub, a plurality of rolling elements, and a sealing device.
Of these, the outer ring has an outer ring raceway on the inner peripheral surface, and does not rotate while being supported and fixed to the suspension device during use.
The hub is disposed concentrically with the outer ring on the inner diameter side of the outer ring, and an inner ring raceway is formed on a portion of the outer peripheral surface facing the outer ring raceway, and a part protruding from the axial outer end opening of the outer ring. The rotating side flanges are respectively provided, and in use, the wheels are coupled and fixed to the rotating side flanges and rotate together with the wheels.
Each rolling element is provided between the outer ring raceway and the inner ring raceway so as to be freely rollable.
The sealing device is for closing an axially outer end opening of an internal space existing between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub, and includes a slinger, a seal ring, and a slinger seal A member.
Of these, the slinger is formed in an annular shape by a metal plate having corrosion resistance, and a fitting cylinder portion fitted on a portion of the outer peripheral surface of the hub adjacent to the axially inner side of the rotation side flange; The side plate portion provided in a state bent radially outward from the axial outer end edge of the fitting cylinder portion, and provided in a state bent inward in the axial direction from the outer peripheral edge of the side plate portion, And a flange-shaped tube portion having an inner peripheral surface of the tip portion closely opposed to an outer peripheral surface of the outer end in the axial direction of the outer ring.
The seal ring includes an annular cored bar fixed to the outer end in the axial direction of the outer ring, and a seal ring sealing member made of an elastic material reinforced by the cored bar. This seal ring seal member has a plurality of seal lips, of which the tip edge of a part of the seal lip is the outer peripheral surface of the fitting cylinder part and the tip edge of the remaining seal lip is the side plate. The inner surface of each part is in sliding contact with the entire circumference.
The slinger sealing member is made of an elastic material, and seals a portion between the slinger and the inner surface of the rotation side flange while being fixed to a part of the slinger.

  In particular, in the wheel support bearing unit of the present invention, the rotation-side flange has a stepped portion formed on the inner surface with a thick portion provided on the inner diameter side and a thin portion provided on the outer diameter side. The diameter dimension of the inner end edge in the axial direction of the step portion is made smaller than the outer diameter dimension of the outer end portion in the axial direction of the outer ring. The slinger sealing member has a gasket portion fixed to the outer surface of the side plate portion, and a flange portion provided radially outward from the gasket portion. Of these, the gasket portion is elastically brought into contact with the entire inner periphery of the inner surface of the rotation-side flange to the radially inner portion of the stepped portion. Further, the front end portion of the flange portion is made to face and oppose the entire outer periphery of the inner side surface of the rotation-side flange to the radially outer portion of the step portion, and the front end portion of the flange portion and the step portion Are superimposed in the radial direction.

  When carrying out the present invention, preferably, as in the invention described in claim 2, as the slinger sealing member, a side surface covering portion that covers at least the outer diameter side portion of the outer surface of the side plate portion; A peripheral surface covering portion that covers an outer peripheral surface of the bowl-shaped cylindrical portion, and an inner diameter side portion of the side surface covering portion is used as the gasket portion, and the axially outer end portion of the peripheral surface covering portion is Further, a flange portion is provided, and the peripheral surface covering portion and the outer peripheral surface of the flange portion are configured to have an inclined surface inclined in a direction in which the diameter dimension increases toward the inner side in the axial direction.

  In carrying out the present invention, preferably, as in the third aspect of the present invention, a portion of the outer surface of the gasket portion that is elastically brought into contact with the inner surface of the rotating side flange, Convex portions are formed over the entire circumference, and relief grooves are formed over the entire circumference in portions of the outer surface adjacent to both sides in the radial direction of the convex portions.

Moreover, when implementing this invention, the structure for preventing the movement of the said slinger to the axial direction inner side with respect to the said hub can also be added.
Specifically, as such a structure, for example, a concave groove extending over the entire circumference is formed in a part in the axial direction of a portion of the outer peripheral surface of the hub where the fitting cylindrical portion constituting the slinger is externally fitted. In addition, it is possible to employ a structure in which an engaging portion provided in a part of the fitting cylinder portion is engaged with the concave groove.
Alternatively, on the outer peripheral surface of the hub, the locking protrusions are formed on the entire circumference or one or more circumferential directions of the portion adjacent to the inner side in the axial direction with respect to the portion that fits the fitting cylindrical portion constituting the slinger. In addition, it is possible to employ a structure in which the inner end edge of the fitting cylinder portion is engaged with the locking projection.
Alternatively, a portion of the outer peripheral surface of the hub that externally fits the fitting cylinder portion that constitutes the slinger is a male serration portion that has been subjected to a hardening treatment such as induction hardening, and the male serration portion As the fitting cylinder part is press-fitted, the male serration part is cut or plastically deformed by the male serration part so that the male serration part is inserted into the inner circumference of the fitting cylinder part. It is also possible to adopt a structure that mechanically bites into the surface (engagement like serration engagement with tightening allowance). When this structure is adopted, not only can the effect of preventing the slinger to move inward in the axial direction with respect to the hub, but also the effect of preventing the rotation of the slinger with respect to the hub can be sufficiently enhanced.

  As described above, in the case of the wheel support bearing unit of the present invention, the slinger seal member is formed on the outer diameter side of the contact portion between the gasket portion constituting the slinger seal member and the inner surface of the rotation side flange. The buttocks to be placed are arranged. For this reason, it is possible to prevent rainwater or muddy water splashed from the road surface from directly hitting the contact portion between the gasket portion and the inner surface of the rotation side flange. Furthermore, the front-end | tip part of the said collar part and the inner surface of the said rotation side flange are facing and adjoining over the perimeter. For this reason, it becomes difficult for the rainwater and muddy water to reach the contact portion between the inner surface of the rotating side flange and the gasket portion through the portion between the tip of the flange portion and the inner surface of the rotating side flange. Yes. Therefore, even when the tightening margin of the gasket portion with respect to the inner surface of the rotation side flange is reduced in a properly assembled state, the sealing performance between the hub surface and the slinger surface can be ensured. In other words, even when this sealing performance is ensured, the fastening allowance can be reduced. For this reason, the elastic force applied to the inner side in the axial direction from the gasket portion to the side plate portion of the slinger can be kept small. As a result, due to this elasticity, the inner side surface of the side plate portion is elastically distorted, and it becomes impossible to sufficiently secure the sealing performance by the seal lip whose sliding edge is in sliding contact with the inner side surface. It can be avoided that the slinger moves axially inward with respect to the hub and the sliding contact pressure between the inner surface of the side plate portion and the tip edge of the seal lip increases.

  Further, in the case of the present invention, it is the outer diameter dimension of the thick portion constituting the inner diameter side portion of the rotation side flange, and the diameter dimension of the axial inner end edge of the step portion provided on the inner surface of the rotation side flange. Is made smaller than the outer diameter of the outer end of the outer ring in the axial direction. For this reason, the ratio of the thin part which comprises the outer diameter side part of the said rotation side flange can be increased, and the weight reduction of the said hub can be aimed at by that much. Furthermore, since the gasket portion is in contact with the inner diameter side portion of the inner surface of the rotation side flange with respect to the stepped portion, the diameter of the contact portion can be reduced. Therefore, at the time of manufacturing the hub, the contact portion and the inner ring raceway can be easily ground at the same time.

Moreover, if the structure of the invention described in claim 2 is adopted, when water such as rain water or muddy water adheres to the outer peripheral surface of the peripheral surface covering portion and the heel portion constituting the slinger seal member, the centrifugal force is reduced. By the action, the adhered moisture can be swung away to the outer diameter side while flowing inward in the axial direction along the outer peripheral surface. For this reason, it can prevent that the water | moisture content adhering to the said outer peripheral surface is guide | induced to the part between the front-end | tip part of the said collar part, and the inner surface of a rotation side flange. Therefore, the sealing performance between the surface of the hub and the surface of the slinger can be improved accordingly.
Further, in the case of the invention described in claim 2, the outer side surface of the side plate portion constituting the slinger has a side surface covering that constitutes a slinger seal member, the portion radially outside the portion to which the gasket portion is fixed. It is covered by the part. For this reason, when water such as rain water or muddy water enters the space sandwiched between the flange portion and the gasket portion through the portion between the inner surface of the rotation side flange and the distal end portion of the flange portion. However, this moisture does not reach the state between the inner side surface of the rotation side flange and the outer side surface of the side plate portion. Therefore, this moisture does not cause electrolytic corrosion on the inner surface of the rotating flange.

  If the configuration of the invention described in claim 3 is adopted, the outer side surface of the gasket portion is elastically brought into contact with the inner side surface of the rotation side flange over the entire circumference. The tightening margin can be locally increased at a portion corresponding to the convex portion provided on the outer surface. For this reason, the sealing performance of the gasket portion can be enhanced at the portion corresponding to the convex portion. In addition, in this state, the meat (elastic material) of the portion corresponding to the convex portion crushed by the inner surface of the rotation-side flange is on both sides in the radial direction of the convex portion of the outer surface of the gasket portion. It moves to a pair of escape groove portions provided in adjacent portions. For this reason, the elastic reaction force in the axial direction (axial elasticity applied from the gasket portion to the side plate portion of the slinger) generated when the convex portion is crushed can be appropriately suppressed.

The figure similar to FIG. 10 which shows the 1st example of embodiment of this invention. The A section enlarged view of FIG. 1 which abbreviate | omits and shows a rotation side flange. The figure similar to FIG. 1 which shows the 2nd example. The principal part sectional view showing the 3rd example. The principal part sectional view showing the 4th example. The principal part sectional view showing the 5th example. The principal part sectional view showing the 6th example. The principal part sectional view showing the 7th example. The half part sectional view showing an example of conventional structure. The B section enlarged view of FIG. 9 showing the specific structure.

[First example of embodiment]
1 and 2 show a first example of an embodiment of the present invention. The features of this example are the structure of the slinger 13a and the slinger seal member 15a in the sealing device 11a that closes the axially outer end opening of the internal space 10, and the structure of the rotating side flange 9a that constitutes the hub body 6a. It is in. Since the structure and operation of other parts are the same as those of the conventional structure shown in FIGS. 9 to 10 described above, the same parts are denoted by the same reference numerals, and overlapping illustrations and descriptions are omitted or simplified. Hereinafter, the characteristic part of this example and the part that has not been described in the above-described conventional structure will be mainly described.

In the case of this example, the rotation side flange 9a is formed by continuously connecting a thick portion 22 provided on the inner diameter side and a thin portion 23 provided on the outer diameter side by a step portion 24 formed on the inner surface. The cross-sectional shape of the stepped portion 24 is a concave arc shape that is inclined in a direction in which the diameter dimension decreases toward the inner side in the axial direction. In particular, in the case of this example, the diameter dimension d ₂₄ of the inner end edge in the axial direction of the stepped portion 24 is smaller than the outer diameter dimension D _1a of the outer end portion in the axial direction of the outer ring 1a (d ₂₄ <D _1a ). Note that the inner side surface and the outer peripheral surface of the hub main body 6a are provided at the inner end portion in the radial direction of the inner surface of the rotating flange 9a (the radial intermediate portion and inner end portion of the inner surface of the thick portion 22). Among them, a corner R portion 26 having a concave arcuate cross section is provided to smoothly connect the cylindrical surface portion 25 existing in a portion adjacent to the inner side in the axial direction of the rotation side flange 9a.

  The slinger 13a is made of a stainless steel plate, which is a metal plate having corrosion resistance, and is formed in an annular shape. The fitting cylinder 16a and the outer edge in the axial direction of the fitting cylinder 16a are radially outward. A side plate portion 17a provided in a bent state, and a bowl-shaped tube portion 18a provided in a state bent inward in the axial direction from the outer peripheral edge of the side plate portion 17a. Of these, the fitting cylinder portion 16a has a simple cylindrical shape. Further, the side plate portion 17a includes a curved plate portion 27 having an arcuate cross section that is curved in the same direction as the corner R portion 26 and a crank portion in cross section that forms a radially outer half portion. And an annular portion 28. Of these, the curvature radius of the outer surface (inner peripheral surface) of the curved plate portion 27 is made slightly larger than the curvature radius of the corner R portion 26. The annular portion 28 includes an outer peripheral edge of the inner diameter side annular portion 29 and an outer diameter side annular portion 30 disposed at a position slightly shifted inward in the axial direction with respect to the inner diameter side annular portion 29. The inner peripheral edge is made continuous by the inclined plate portion 31. The flange-shaped cylindrical portion 18a has a cylindrical shape concentric with the fitting cylindrical portion 16a, and is provided with a flange 32 bent radially outward at an axially inner end portion.

  Then, in the assembled state shown in the drawing, the fitting cylinder portion 16a is externally fitted to the cylindrical surface portion 25 of the hub body 6a with an interference fit. At the same time, the outer surface of the side plate portion 17a is not brought into direct contact with the inner surface of the rotating side flange 9a, but only through the gasket portion 36 of the slinger seal member 15a described later, The slinger 13a is positioned in the axial direction. Further, in this state, the inner peripheral surface of the front half of the flange-shaped cylindrical portion 18a is brought close to and opposed to the outer peripheral surface of the outer end in the axial direction of the outer ring 1a, and the portion between these peripheral surfaces is used as the labyrinth seal portion Yes. In this state, of the three seal lips 21a, 21b and 21c constituting the seal ring seal member 20 of the seal ring 14 (shown in a free state in FIG. 1), the tip of the seal lip 21a called a grease lip The edge is on the outer peripheral surface of the fitting cylinder portion 16a, the front edge of the seal lip 21b called main lip is on the inner surface (outer peripheral surface) of the curved plate portion 27, and the front edge of the seal lip 21c called side lip is The inner side surface of the inner diameter side annular portion 29 is in sliding contact with the entire circumference.

  The slinger seal member 15a (shown in a free state in FIG. 1) is formed in an annular shape by an elastic material such as rubber, and is fixed to the slinger 13a by baking or the like. Such a slinger sealing member 15a includes a side surface covering portion 33 that covers the outer surface of the ring-shaped portion 28, a peripheral surface covering portion 34 that covers the outer peripheral surface of the bowl-shaped cylindrical portion 18a, and the peripheral surface covering portion 34. And a cylindrical flange 35 protruding outward in the axial direction from the axial outer end edge (the outer peripheral edge of the side surface covering portion 33). Further, a portion of the side surface covering portion 33 that covers the outer surface of the inner diameter side annular ring portion 29 is a gasket portion 36. In the case of this example, as shown in detail in FIG. 2, on the outer surface of the gasket portion 36, a convex portion 43 having a triangular cross section and a pointed shape is formed over the entire circumference in the central portion in the radial direction. The relief grooves 44a and 44b, each having a concave arc shape in cross section, are formed over the entire circumference at portions adjacent to both sides in the radial direction of the convex portion 43. Furthermore, in the case of this example, the outer peripheral surfaces of the peripheral surface covering portion 34 and the flange portion 35 are tapered surfaces that are inclined in a direction in which the diameter dimension decreases toward the outer side in the axial direction.

  Then, in the assembled state shown in the figure, the outer surface of the gasket portion 36 is elastic over the entire circumference to the radially outer end (annular surface) of the inner surface of the thick portion 22 constituting the rotation side flange 9a. In contact. Further, the front end portion of the flange portion 35 is closely opposed to the radially inner end portion (annular surface) of the inner surface of the thin wall portion 23 constituting the rotation side flange 9a over the entire circumference, and the flange portion 35 is also opposed. And the stepped portion 24 are superposed in the radial direction. Further, in the case of this example, the outer peripheral surfaces of the peripheral surface covering portion 34 and the flange portion 35 are tapered surfaces with the axial outer end portion having the smallest diameter portion as described above. Further, it is easy to prevent interference with the head portion 38 (see FIG. 9) of the wheel coupling stud 37 fixed to the outer peripheral portion of the rotation side flange 9a.

  Also in the case of the wheel support bearing unit of the present example having the above-described configuration, as in the case of the above-described conventional structure, the sealing device 11a is slidably contacted with the end edges of the seal lips 21a, 21b, 21c. The surface of the slinger 13a made of a metal plate having corrosion resistance is employed as the mating surface. For this reason, the life of the sealing performance by the seal lips 21a, 21b, and 21c can be extended by suppressing the deterioration of the properties of the mating surface (deterioration of the surface roughness due to rusting). Further, it is possible to prevent rainwater and muddy water splashed from the road surface from directly hitting the seal ring 14 based on the presence of the bowl-shaped cylinder portion 18a constituting the slinger 13a, and the installation portion of the seal ring 14 The sealing performance by the sealing device 11a can be improved by the amount that it is difficult to enter the device. Further, an outer end portion between the surface of the slinger 13a and the surface of the hub body 6a is sealed by the gasket portion 36 constituting the slinger seal member 15a. For this reason, it is possible to prevent the grease in the internal space 10 from leaking to the external space and the entry of foreign matter such as rainwater and muddy water from the external space into the internal space 10 through this portion. Further, since it is possible to prevent water from entering between the surface of the slinger 13a and the surface of the hub body 6a, there is a gap between the material of the slinger 13a (stainless steel) and the material of the hub body 6a (carbon steel). The occurrence of electrolytic corrosion due to the standard electrode potential difference can also be prevented.

  In particular, in the case of this example, on the outer diameter side of the contact portion between the outer surface of the gasket portion 36 and the inner surface of the rotation side flange 9a (the radially outer end of the inner surface of the thick portion 22). A flange 35 constituting the slinger sealing member 15a is disposed. For this reason, it is possible to prevent rainwater or muddy water splashed from the road surface from directly hitting the contact portion between the outer side surface of the gasket portion 36 and the inner side surface of the rotation side flange 9a. In the case of this example, the front end of the flange 35 and the inner surface of the rotation side flange 9a (the radially inner end of the inner surface of the thin portion 23) are closely opposed over the entire circumference. ing. For this reason, the rain water and muddy water contact the outer side surface of the gasket portion 36 and the inner side surface of the rotary side flange 9a through the portion between the tip of the flange 35 and the inner side surface of the rotary side flange 9a. It is difficult to reach the part. Furthermore, in the case of this example, the outer peripheral surfaces of the peripheral surface covering portion 34 and the flange portion 35 are tapered surfaces that are inclined in a direction in which the diameter dimension increases toward the inner side in the axial direction. For this reason, when moisture such as rain water or muddy water adheres to the outer peripheral surface, the water is swung toward the outer diameter side while flowing inward in the axial direction along the outer peripheral surface by the action of centrifugal force. To be skipped. That is, the moisture adhering to the outer peripheral surface is prevented from being guided to a portion between the tip end portion of the flange portion 35 and the inner side surface of the rotation side flange 9a. That is, in the case of this example, the rainwater and the muddy water are less likely to reach the contact portion between the outer side surface of the gasket portion 36 and the inner side surface of the rotation side flange 9a by such an action. .

  Therefore, in the case of this example, even when the tightening margin of the outer surface of the gasket portion 36 with respect to the inner surface of the rotation side flange 9a is reduced in a regular assembly state as illustrated, the surface of the slinger 13a The sealing performance with the surface of the hub body 6a can be ensured. In other words, even when this sealing performance is ensured, the fastening allowance can be reduced. For this reason, the elastic force applied to the side plate part 17a of the slinger 13a from the gasket part 36 toward the inner side in the axial direction can be kept small. In particular, in the case of this example, the outer surface of the gasket portion 36 is elastically contacted with the inner surface of the rotation side flange 9a over the entire circumference, and the tightening margin of the outer surface with respect to the inner surface is set. The portion corresponding to the convex portion 43 provided on the outer surface can be locally increased. For this reason, the sealing performance of the gasket portion 36 can be enhanced at a portion corresponding to the convex portion 43. In addition, in this state, the meat (elastic material) of the portion corresponding to the convex portion 43 crushed by the inner surface of the rotation side flange 9 a is not in the outer surface of the gasket portion 36. It moves to a pair of escape grooves 44a and 44b provided in the portions adjacent to both sides in the radial direction. For this reason, the elastic reaction force in the axial direction (axial elasticity applied from the gasket portion 36 to the side plate portion 17a) generated when the convex portion 43 is crushed can be appropriately suppressed. As a result, due to this elasticity, the inner side surface of the side plate portion 17a is elastically distorted, and the sealing performance by the respective seal lips 21b and 21c, whose tip edges are in sliding contact with the inner side surface, cannot be ensured sufficiently. In addition, the elastic force causes the slinger 13a to move inward in the axial direction with respect to the hub 6a, and the sliding contact pressure between the inner side surface of the side plate portion 17a and the leading edge of each of the seal lips 21b and 21c increases. You can avoid things.

  In the case of this example, of the outer surface of the side plate portion 17a constituting the slinger 13a, the portion radially outside the portion to which the gasket portion 36 is fixed is formed by the outer diameter side portion of the side surface covering portion 33. Covered. For this reason, moisture such as rain water and muddy water is passed through the portion between the inner side surface of the rotation side flange 9a and the tip of the flange portion 35 into the space sandwiched between the flange portion 35 and the gasket portion 36. Even when the water enters, the moisture is not suspended between the inner side surface of the rotation-side flange 9a and the outer side surface of the side plate portion 17a. Therefore, this moisture does not cause electrolytic corrosion on the inner surface of the rotating flange 9a.

In the case of this example, it is the outer diameter of the thick portion 22 constituting the inner diameter side portion of the rotation side flange 9a, and the axially inner side of the step portion 24 provided on the inner surface of the rotation side flange 9a. The diameter d ₂₄ of the edge is made smaller than the outer diameter D _1a of the outer end in the axial direction of the outer ring 1a. For this reason, the ratio of the thin part 23 which comprises the outer diameter side part of the said rotation side flange 9a can be increased, and the weight reduction of the said hub main body 6a can be aimed at by that much. Furthermore, since the outer surface of the gasket portion 36 is brought into contact with the inner diameter side portion of the inner surface of the rotation side flange 9a rather than the step portion 24, the diameter of the contact portion can be reduced. Therefore, at the time of manufacturing the hub 6a, the contact portion, the cylindrical surface portion 25, and the inner ring raceway 8a (see FIG. 9) can be easily ground at the same time.

[Second Example of Embodiment]
FIG. 3 shows a second example of the embodiment of the present invention. In the case of this example, the shape of the flange portion 35a constituting the slinger seal member 15b is different from that of the first example shown in FIG. That is, in the first example described above, the cross-sectional shape of the inner peripheral surface of the flange portion 35 is an arc shape in which the side facing the stepped portion 24 provided on the inner side surface of the rotation side flange 9a is concave. In the case of the example, the cross-sectional shape of the inner peripheral surface of the flange portion 35a is an arc shape that is convex toward the step portion 24 provided on the inner surface of the rotation side flange 9a (along this step portion 24). Yes. As a result, the gap width between the inner surface of the rotating flange 9a and the outer surface of the slinger seal member 15b in the radially outer portion of the gasket portion 36 is entirely reduced by capillary action. It is so narrow that it does not occur. Thereby, rain water, muddy water, or the like is made less likely to enter the portion between the two.
Other configurations and operations are the same as those in the case of the first example described above, and a duplicate description is omitted.

[Third example of embodiment]
FIG. 4 shows a third example of the embodiment of the present invention. In the case of this example, a concave groove 39 extending over the entire circumference is formed on the outer peripheral surface of the hub body 6b on the inner end portion in the axial direction of the cylindrical surface portion 25 where the fitting cylinder portion 16b constituting the slinger 13b is externally fitted. Forming. At the same time, a pair of slits spaced apart in the circumferential direction is formed at one or a plurality of locations (preferably at three or more circumferentially spaced intervals) in the inner edge portion of the fitting cylinder portion 16b. Further, a claw portion 40 is formed by bending a portion between the two slits toward the inner diameter side, and the claw portion 40 is engaged with the concave groove 39. Based on the engagement between the concave groove 39 and the claw portion 40, the cylindrical portion 16 b for fitting with respect to the cylindrical surface portion 25 is prevented from coming off in the axial direction.
In the case of implementing the structure of this example, an axial gap that is unavoidable in processing is between the front end edge of the claw portion 40 that is an engaging portion and the axial inner end portion of the inner surface of the groove 39. The slinger 13b may move inward in the axial direction with respect to the hub body 6b by the axial dimension of the axial gap. For this reason, when the structure of this example is implemented, the tightening margin of the convex portion 43 (see FIGS. 1 to 3) with respect to the inner surface of the rotation-side flange 9a is set to be larger than the axial dimension of the axial gap. Even when the above movement occurs, it is preferable to prevent a gap from being formed between the inner surface of the rotation side flange 9a and the convex portion 43.
Since other configurations and operations are the same as those in the above-described first and second examples, overlapping illustration and description are omitted.

[Fourth Example of Embodiment]
FIG. 5 shows a fourth example of the embodiment of the present invention. In the case of this example, of the outer peripheral surface of the hub main body 6c, a portion closer to the inner end in the axial direction of the cylindrical surface portion 25 where the fitting cylindrical portion 16a constituting the slinger 13a is externally fitted (the fitting cylindrical portion 16a is externally fitted). A locking projection 41 extending around the entire circumference is formed on a portion adjacent to the inner side in the axial direction. Then, by engaging the inner end edge of the fitting tube portion 16a with the outer end surface of the locking projection 41, the fitting tube portion 16a is prevented from coming off in the axial direction with respect to the cylindrical surface portion 25. ing. The outer peripheral surface of the locking protrusion 41 is a partial conical inclined surface that is inclined in a direction in which the diameter dimension decreases from the outer side in the axial direction toward the inner side in the axial direction. The surface portion 25 is smoothly continuous with the inner end portion in the axial direction. In the case of this example, when the fitting cylinder portion 16 a is press-fitted into the cylindrical surface portion 25 from the inner side in the axial direction, the fitting cylinder portion 16 a extends along the outer peripheral surface of the locking projection 41. In this case, the height in the radial direction of the locking projection 41 is regulated to such an extent that the fitting cylinder portion 16 does not undergo plastic deformation.

In the case of this example, at the time of manufacturing the hub body 6c, the portion of the surface of the hub body 6c that contacts the outer surface of the gasket portion 36 (see FIGS. 1 and 3), the cylindrical surface portion 25, and the inner ring Simultaneous grinding is performed on the track 8a (see FIG. 9) by a grindstone that enters from a direction that makes an angle of about 60 degrees with respect to the central axis of the hub body 6c. However, at this time, a portion of the cylindrical surface portion 25 that is adjacent to the outside in the axial direction of the locking projection 41 enters the blind spot of the locking projection 41, and therefore cannot be ground. Therefore, in the case of this example, in order to eliminate the need for grinding of the part, a relief groove 42 extending over the entire circumference is formed in the part.
When the structure of this example is carried out, an axial gap inevitable in processing is formed between the inner end edge of the fitting cylinder portion 16a and the outer end surface of the locking projection 41, and this shaft There is a possibility that the slinger 13a moves inward in the axial direction with respect to the hub body 6c by the axial dimension of the directional gap. For this reason, when the structure of this example is implemented, the tightening margin of the convex portion 43 (see FIGS. 1 to 3) with respect to the inner surface of the rotation-side flange 9a is set to be larger than the axial dimension of the axial gap. Even when the above movement occurs, it is preferable to prevent a gap from being formed between the inner surface of the rotation side flange 9a and the convex portion 43.
Other configurations and operations are the same as those in the first and second examples described above, and thus overlapping illustrations and descriptions are omitted.
In the above-described fourth example, the locking protrusion 41 is provided over the entire circumference. However, when the present invention is carried out, such a locking protrusion is provided in one or more circumferential directions (preferably Can be provided at three or more points at equal intervals in the circumferential direction.

[Fifth Example of Embodiment]
FIG. 6 shows a fifth example of the embodiment of the present invention. In the case of this example, a concave groove 39 extending over the entire circumference is formed on the outer peripheral surface of the hub main body 6b near the inner end in the axial direction of the cylindrical surface portion 25 on which the fitting cylinder portion 16c constituting the slinger 13c is externally fitted. Forming. At the same time, a portion of the fitting cylinder portion 16c that is aligned with the concave groove 39 is plastically deformed to the inner diameter side over the entire circumference by using a rolling caulking machine, so that the entire inner circumferential surface of the portion can be obtained. Engaging convex portions 43a that engage with the concave grooves 39 without rattling are formed on the periphery. Then, based on the engagement between the engaging convex portion 43a, which is an engaging portion, and the concave groove 39, the fitting cylindrical portion 16c is prevented from slipping inward in the axial direction with respect to the cylindrical surface portion 25. Yes.
Other configurations and operations are the same as those in the first and second examples described above, and thus overlapping illustrations and descriptions are omitted.

[Sixth Example of Embodiment]
FIG. 7 shows a sixth example of the embodiment of the present invention. In the fifth example described above, the engaging convex portion 43a to be engaged with the concave groove 39 is provided over the entire circumference in a part in the axial direction of the fitting cylinder portion 16c constituting the slinger 13c. The engaging convex portion 43b to be engaged with the concave groove 39 has one or more circumferential directions (preferably three circumferentially spaced locations) in the axial direction part of the fitting cylinder portion 16d constituting the slinger 13d. Above).
Other configurations and operations are the same as those of the fifth example described above.

[Seventh example of embodiment]
FIG. 8 shows a seventh example of the embodiment of the invention. In the case of this example, on the outer peripheral surface of the hub main body 6d, a portion {fitting the fitting cylinder portion 16e constituting the slinger 13e {adjacent to the inner side in the axial direction of the rotation side flange 9a (see FIGS. 1 and 3). Portion} is a male serration portion 44. The male serration 44 is subjected to induction hardening (hardening) along with the inner ring raceway 8a (see FIG. 9) and the like. Then, as the fitting cylinder part 16e is press-fitted into the male serration part 44 that has been subjected to such a hardening process, the male peripheral part 44 cuts the inner peripheral surface of the fitting cylinder part 16e. Alternatively, the male serration portion 44 is mechanically bitten into the inner peripheral surface of the fitting cylinder portion 16e by being plastically deformed (engaged like serration engagement with a tightening margin). This enhances the effect of preventing the slinger 13e from rotating and moving in the axial direction with respect to the hub body 6d. Such a structure, like the slinger 13e, can be preferably used as a structure for preventing the occurrence of creep related to a component having a large outer diameter side and a short axial dimension of the fitting cylinder portion 16e. .
Other configurations and operations are the same as those in the first and second examples described above, and thus overlapping illustrations and descriptions are omitted.

  The present invention is not limited to the wheel support bearing unit as shown in FIG. 9, but may be a conventionally known wheel support bearing unit of various structures (whether it is for a driven wheel or a drive wheel). Not applicable).

DESCRIPTION OF SYMBOLS 1, 1a Outer ring 2 Hub 3 Rolling element 4 Stationary side flange 5a, 5b Outer ring raceway 6, 6a, 6b, 6c, 6d Hub body 7 Inner ring 8a, 8b Inner ring raceway 9, 9a Rotation side flange 10 Inner space 11, 11a Sealing device 12 Cover 13, 13a, 13b, 13c, 13d, 13e Slinger 14 Seal ring 15, 15a, 15b Slinger seal member 16, 16a, 16b, 16c, 16d, 16e Fitting cylinder 17, 17a Side plate 18, 18a Shaped cylinder part 19 Core 20 Seal ring sealing member 21a, 21b, 21c Seal lip 22 Thick part 23 Thin part 24 Step part 25 Cylindrical surface part 26 Corner R part 27 Curved plate part 28 Circular ring part 29 Inner diameter side annular part 30 outer diameter side annular part 31 inclined plate part 32 collar part 33 side surface covering part 34 peripheral surface covering part 35 collar part 36 Socket portion 37 the stud 38 the head 39 the groove 40 the claw portion 41 engaging projection 42 relief grooves 43a, 43b engaging projection 44 male serration portion

Claims (3)

An outer ring that has an outer ring raceway on the inner peripheral surface and that does not rotate while being supported and fixed to the suspension device when in use, and is arranged concentrically with the outer ring on the inner diameter side of the outer ring and faces the outer ring raceway on the outer peripheral surface A hub that has an inner ring raceway in the part to be rotated and a rotary flange at the part that protrudes from the axially outer end opening of the outer ring, and that rotates together with the wheel while the wheel is coupled and fixed to the rotary flange at the time of use. A plurality of rolling elements provided between the outer ring raceway and the inner ring raceway so as to be freely rollable, and an axial direction of an internal space existing between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub And a sealing device for closing the outer end opening,
The sealing device includes a slinger, a seal ring, and a slinger seal member.
Of these, the slinger is formed in an annular shape by a metal plate having corrosion resistance, and a fitting cylinder portion fitted on a portion of the outer peripheral surface of the hub adjacent to the axially inner side of the rotation side flange; The side plate portion provided in a state bent radially outward from the axial outer end edge of the fitting cylinder portion, and provided in a state bent inward in the axial direction from the outer peripheral edge of the side plate portion, A tip-shaped inner peripheral surface of the outer ring in the axial direction outer end portion of the outer peripheral surface close to and opposed to the flanged cylindrical portion,
The seal ring includes an annular cored bar fixed to the outer end portion in the axial direction of the outer ring, and a seal ring seal member made of an elastic material reinforced by the cored bar, and the seal ring seal member Has a plurality of seal lips, of which the tip edge of a part of the seal lip is on the outer peripheral surface of the fitting cylinder part, and the tip edge of the remaining seal lip is on the inner surface of the side plate part, Each is in contact with the entire circumference,
The slinger sealing member is made of an elastic material, and in a state of being fixed to a part of the slinger, is sealing a portion between the slinger and the inner surface of the rotation side flange.
In the wheel support bearing unit,
The rotation-side flange is formed by continuously connecting a thick part provided on the inner diameter side and a thin part provided on the outer diameter side by a step part formed on the inner side surface. The diameter dimension of the edge is smaller than the outer diameter dimension of the outer end in the axial direction of the outer ring,
The slinger sealing member has a gasket portion fixed to the outer side surface of the side plate portion, and a flange portion provided radially outward from the gasket portion, of which the gasket portion is Of the inner side surface of the rotation side flange, it is elastically contacted with the entire inner periphery of the step portion, and the tip end portion of the flange portion is made of the inner side surface of the rotation side flange. The wheel support bearing unit is characterized in that the front end portion of the flange portion and the step portion are overlapped in the radial direction in close proximity to the radially outer portion of the step portion over the entire circumference.   The slinger sealing member has a side surface covering portion that covers at least the outer diameter side portion of the outer surface of the side plate portion, and a peripheral surface covering portion that covers the outer peripheral surface of the bowl-shaped cylindrical portion, The inner diameter side portion of the side surface covering portion is the gasket portion, and the flange portion is provided at the axially outer end portion of the peripheral surface covering portion, and the outer peripheral surface of the peripheral surface covering portion and the flange portion is The wheel support bearing unit according to claim 1, wherein the bearing surface is an inclined surface that is inclined in a direction in which a diameter dimension increases toward an inner side in the axial direction. Convex portions are formed over the entire circumference of a portion of the outer surface of the gasket portion that is elastically brought into contact with the inner surface of the flange on the rotation side. The bearing unit for wheel support described in any one of Claims 1-2 in which the escape groove which extends over the perimeter is formed in the part adjacent to each.

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