JP2023059013A - sealing device - Google Patents

Abstract

To provide a sealing device used in a wheel bearing device, which can realize low torque while keeping muddy water resistance.SOLUTION: A surface contact region 13e that is brought into surface contact with a hub wheel 4 is provided on the tip inner diameter surfaces of axial contact lips 13a, 13b, and recessed parts 13f, 13g for reducing a contact area with the hub wheel 4 with the annular surface contact region 13e left on its inner diameter side are provided in the surface contact region 13e, so that it is possible to realize low torque, and keep muddy water resistance by leaving the annular surface contact region on the inner diameter side of the recessed parts 13f, 13g.SELECTED DRAWING: Figure 3

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device used in a wheel bearing device for rotatably supporting a wheel of an automobile or the like with respect to a suspension device.

A wheel bearing device is provided with a sealing device between an outer member and an inner member to prevent foreign matter such as muddy water from entering.

The outer side sealing device provided with the wheel mounting flange of the wheel bearing device is fitted to the outer side end portion of the outer member and closes the outer side opening of the annular space formed by the outer member and the inner member. closing the ends.

The sealing device on the outer side of the bearing device for a wheel is improved in sealing performance by, for example, forming three lips in order to increase the effect of resistance to muddy water.

The sealing devices of FIGS. 8 and 9 are examples of three-lipped sealing devices.

FIG. 8 shows the state before the sealing device is attached to the wheel bearing device, and FIG. 9 shows the state after it is attached to the wheel bearing device.

This conventional sealing device includes a core metal 61 fitted to the outer member 51 and a rubber sealing member 62 joined to the core metal 61 .

The core metal 61 is formed by pressing a steel plate, for example, and consists of a cylindrical portion 61a and a bent portion 61b as shown in FIG.

The seal member 62 extends in the axial direction toward the wheel mounting flange 52a of the hub wheel 52 and extends radially inward toward the outer peripheral surface of the hub wheel 52 along with a pair of axial contact lips 62a and 62b that contact the hub wheel 52. , and a grease lip 62 c that contacts the hub wheel 52 .

A pair of axial contact lips 62a and 62b of the seal member 61 are in line contact with the hub wheel 52 at their tips to maintain sealing performance.

Such a 3-lip sealing device is highly effective against muddy water, but tends to increase rotational torque. ) are used as countermeasures (Patent Documents 1 to 3).

Japanese Patent Application Laid-Open No. 2021-36169 WO2017/038751 WO2017/061242

However, although the labyrinth (non-contact) seal lip enables low torque, the muddy water resistance performance is lowered, and there is concern that problems may occur due to muddy water intrusion.

SUMMARY OF THE INVENTION Accordingly, the present invention is intended to achieve low torque while maintaining muddy water resistance without labyrinthizing the seal lip.

In order to solve the above-mentioned problems, the present invention provides an outer member integrally formed with a double-row outer raceway surface on the inner periphery, a hub wheel having a wheel mounting flange on the outer side, and the double-row outer member on the outer periphery. An inner member having an inner raceway surface facing the outer raceway surface of the row, and double-row rolling elements rollably accommodated between the raceway surfaces of the inner member and the outer member. A sealing device used in a wheel bearing device is constructed as follows.
That is, the sealing device of the present invention includes a core bar fitted to the outer member, which closes an outer-side opening end of an annular space formed by the outer member and the inner member, and a core bar joined to the core bar. a sealing member, the sealing member extending in the axial direction toward the wheel mounting flange of the hub wheel and contacting the hub wheel or the slinger mounted on the outer diameter surface of the hub wheel; and the outer periphery of the hub wheel. and a grease lip extending radially inwardly toward the surface, and the axial contact lip has a surface contact area on the tip inner diameter surface that makes surface contact with the hub wheel or the slinger mounted on the outer diameter surface of the hub wheel. In this surface contact area, an annular surface contact area is left at least on the inner diameter side, and a recess is provided to reduce the contact area with the hub wheel or the slinger attached to the outer diameter surface of the hub wheel.

The grease lip may be of a type that contacts the hub wheel or a slinger attached to the outer diameter surface of the hub wheel, or of a non-contact type.

The recessed portions may be intermittently arranged in the circumferential direction of the axial contact lip.

Further, the recessed portion may be a through hole penetrating the axial contact lip from the inner diameter side to the outer diameter side, or may be formed in the shape of an annular groove.

As described above, the sealing device according to the present invention has a surface contact area on the tip inner diameter surface of the axial contact lip that makes surface contact with the hub wheel or the slinger attached to the outer diameter surface of the hub wheel. A reduction in torque is achieved by providing the surface contact area with a recess that reduces the contact area with the hub wheel or the slinger attached to the outer diameter surface of the hub wheel, leaving at least an annular surface contact area on the inner diameter side. By leaving an annular surface contact area on the inner diameter side of the recess, the muddy water resistance can be maintained. In other words, the recessed portion reduces the contact area of the axial contact lip, reducing torque. ) is preserved.

Further, by forming the recessed portion as a through-hole, grease (oil) is collected in the through-hole, thereby enhancing the effect of preventing the oil film from running out of the sliding portion. If the recessed portion is filled with grease, the sliding portion is automatically replenished with grease through the recessed portion.

Furthermore, since the tip portion of the axial contact lip is bent and brought into surface contact, the axial contact lip can be made thin, so that the tightening force can be reduced and the torque can be reduced.

1 is a longitudinal sectional view showing an embodiment of a wheel bearing device using a sealing device of the present invention; FIG. 1 is a cross-sectional view showing an embodiment of a sealing device of the present invention before being mounted on a wheel bearing device; FIG. FIG. 3 is a partially enlarged cross-sectional view showing a state in which the sealing device of FIG. 2 is attached to a wheel bearing device; FIG. 3 is a partially enlarged view of the sealing device of FIG. 2 as seen from the inner diameter side; FIG. 4 is a cross-sectional view showing another embodiment of the sealing device of the present invention before being mounted on the wheel bearing device; 6 is a partially enlarged view of the sealing device of FIG. 5 viewed from the inner diameter side; FIG. 3 is a partially enlarged cross-sectional view showing an embodiment in which the sealing device of FIG. 2 is used in a wheel bearing device equipped with a slinger; FIG. FIG. 3 is a cross-sectional view showing a conventional sealing device before being attached to a wheel bearing device; FIG. 9 is a partially enlarged cross-sectional view showing a state in which the sealing device of FIG. 8 is attached to the wheel bearing device;

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following description, the side closer to the outside of the vehicle when assembled to the vehicle is called the outer side (left side in FIG. 1), and the side closer to the center is called the inner side (right side in FIG. 1).

The wheel bearing device shown in FIG. 1 is for a driven wheel called the third generation, and is housed between an inner member 1 and an outer member 2, and both members 1 and 2 so as to be free to roll. Double row rolling elements 3, 3 are provided.

The inner member 1 comprises a hub wheel 4 and an inner ring 5 press-fitted into the hub wheel 4 .

The hub wheel 4 integrally has a wheel mounting flange 4b for mounting a wheel on the outer end, and the wheel or the like of the wheel and the hub wheel 4 are fastened at the equidistant positions on the circumference of the wheel mounting flange 4b. A hub bolt 6 is installed.

The outer periphery of the hub wheel 4 is formed with one (outer side) inner raceway surface 4a and a cylindrical small-diameter stepped portion 4c extending from the inner raceway surface 4a toward the inner side.

An inner ring 5 having the other (inner side) inner raceway surface 5a on its outer periphery is press-fitted into the small-diameter stepped portion 4c of the hub wheel 4 . A caulking portion 4d that is plastically deformed radially outward is formed at the end of the small-diameter stepped portion 4c. It is axially fixed in the

The outer member 2 integrally has a vehicle body attachment flange 2a for attachment to a knuckle (not shown) on its outer circumference, and has double-row outer raceways on its inner circumference facing the double-row inner raceway surfaces 4a and 5a. It has faces 2b and 2b.

Between the outer raceway surfaces 2b, 2b of the outer member 2 and the double-row inner raceway surfaces 4a, 5a opposed to the outer raceway surfaces 2b, 2b, double-row rolling elements 3, 3 are accommodated, respectively. It is rotatably held by retainers 7.7.

Furthermore, a bottomed cylindrical bearing cap 8 made of synthetic resin is attached to the inner opening end of the outer member 2 . The bearing cap 8 closes the inner opening of the outer member 2 to prevent rainwater, dust, or the like from entering the wheel bearing from the outside.

A pulsar ring 9 is fitted on the outer diameter of the inner ring 5 . The pulsar ring 9 is composed of an annular support ring 9a and a magnetic encoder 9b vulcanized and bonded to the side surface of the support ring 9a. The bearing cap 8 has a mounting portion 8b to which the sensor unit 10 is mounted. The sensor unit 10 includes a magnetic encoder 9b of the pulsar ring 9 and a rotational speed sensor arranged opposite to each other with a predetermined air gap therebetween.

As shown in FIGS. 2 and 3, a sealing device 11 is attached to the outer open end of the annular space formed by the outer member 2 and the inner member 1 .

The sealing device 11 includes a cored bar 12 and a seal member 13 joined to the cored bar 12 .

The cored bar 12 is formed by pressing a steel plate, for example. As shown in FIG. 2, the cored bar 12 consists of a cylindrical portion 12a and a bent portion 12b.

The cylindrical portion 12 a is fitted to the inner peripheral surface of the outer side opening of the outer member 2 . The bent portion 12b extends radially inward while bending from the outer end portion of the cylindrical portion 12a.

A seal member 13 made of, for example, synthetic rubber is joined (here, by vulcanization adhesion) to the core metal 12 .

The seal member 13 extends in the axial direction toward the wheel mounting flange 4b of the hub wheel 4 and extends radially inward toward the outer peripheral surface of the hub wheel 4 along with a pair of axial contact lips 13a and 13b that contact the hub wheel 4. , and a grease lip 13 c that contacts the outer diameter surface of the hub wheel 4 .

The grease lip 13c prevents the grease inside the wheel bearing from leaking to the outside. The pair of axial contact lips 13a and 13b are provided radially outside the grease lip 13c.

As shown in FIG. 3, the distal end portions of the pair of axial contact lips 13a and 13b are formed thin such that the inner diameter surfaces are in surface contact with the hub wheel 4, and this thin portion bends to form a surface contact region 13e. is formed. In FIG. 3, the surface on the side of the hub wheel 4 with which the surface contact regions 13e of the tip inner diameter surfaces of the pair of axial contact lips 13a and 13b come into contact is schematically shown by dark hatching. 4 and 6 are partial side views of the sealing member 13 viewed from the inner diameter side, and the surface contact region 13e is indicated by thin ink.

An annular surface contact area 13e is left on the inner diameter side of the pair of axial contact lips 13a and 13b, and depressions 13f and 13g are provided to reduce the contact area with the hub wheel 4. ing.

In this way, by providing the recessed portions 13f and 13g for reducing the contact area with the hub wheel 4 in the surface contact area 13e located on the inner diameter surface at the tip of the pair of axial contact lips 13a and 13b, low torque is realized. By leaving the annular surface contact region 13e on the inner diameter side of the recessed portions 13f and 13g, it is possible to maintain muddy water resistance.

The recessed portions 13f and 13g penetrate the axial contact lips 13a and 13b from the inner diameter side to the outer diameter side, and as shown in FIG.

By forming the recesses 13f and 13g as through-holes, grease (oil content) accumulates in the through-holes, thereby preventing the oil film from running out of the sliding portion.

Alternatively, as shown in FIGS. 5 and 6, the recessed portions 13f and 13g may be formed in an annular groove shape that does not penetrate from the inner diameter side to the outer diameter side, and the annular grooves that do not penetrate may be arranged intermittently in the circumferential direction. good.

Next, FIG. 7 shows an embodiment in which a slinger 14 having axial contact lips 13a and 13b and a grease lip 13c in sliding contact is attached to the outer diameter surface of the hub wheel 4. As shown in FIG. The grease lip 13c may be non-contact with the slinger 14.

The slinger 14 is formed by pressing a steel plate, for example. The slinger 14 is composed of a cylindrical portion 14a, a bent portion 14b, and a disk portion 14c.

The cylindrical portion 14a is fitted to the shoulder portion 4f of the hub wheel 4 (the portion adjacent to the inner raceway surface 4a on the outer side). A grease lip 13c is in sliding contact with the cylindrical portion 14a via a grease oil film. The bent portion 14b expands radially outward from the outer end portion of the cylindrical portion 14a toward the outer side. An inner axial contact lip 13b is in sliding contact with the bent portion 14b via a grease film. The disc portion 14c extends radially outward from the distal end portion of the bent portion 14b. An outer axial contact lip 13a is in sliding contact with the disc portion 14c via a grease film.

7 also has a surface contact region 13e that makes surface contact with the slinger 14 on the inner diameter surfaces at the tips of the pair of axial contact lips 13a and 13b. Recessed portions 13f and 13g are provided to reduce the contact area with the slinger 14 while leaving the surface contact region 13e. The recessed portions 13d and 13e in the embodiment of FIG. 7 are through holes that pass through the axial contact lips 13a and 13b from the inner diameter side to the outer diameter side and are intermittently arranged in the circumferential direction.

In the embodiment of FIG. 7, a low torque is realized by providing recessed portions 13d and 13e for reducing the contact area with the slinger 14 in the surface contact area 13e of the tip inner diameter surfaces of the pair of axial contact lips 13a and 13b. By leaving the annular surface contact region 13e on the inner diameter side of the recessed portions 13f and 13g, it is possible to maintain muddy water resistance.

The present invention is by no means limited to the above-described embodiments, and can of course be embodied in various forms without departing from the gist of the present invention. and includes equivalents and all changes within the scope of the claims. Moreover, as the rolling elements 3, 3, not only balls but also rollers can be adopted.

Reference Signs List 1: Inner member 2: Outer member 2a: Car body mounting flange 2b: Outer raceway surface 3: Rolling elements
4: hub ring 4a: inner raceway surface 4b: wheel mounting flange 5: inner ring 5a: inner raceway surface 7: retainer
11: Sealing device 12: Metal core
12a: Cylindrical portion 12b: Bent portion 13: Seal members 13a and 13b: Axial contact lip 13c: Grease lip 13e: Surface contact areas 13f and 13g: Recessed portion 14: Slinger

Claims (5)

An outer member having a double-row outer raceway surface integrally formed on the inner circumference, a hub wheel having a wheel mounting flange on the outer side, and an inner raceway surface facing the double-row outer raceway surface. 1. A sealing device used in a wheel bearing device comprising a square member and double-row rolling elements rotatably accommodated between the raceway surfaces of the inner member and the outer member, the sealing device comprising: The device includes a metal core fitted to the outer member and a sealing member joined to the metal core, which closes an outer-side open end of an annular space formed by the outer member and the inner member, The sealing member includes an axial contact lip that extends in the axial direction toward the wheel mounting flange of the hub wheel and contacts the hub wheel or a slinger mounted on the outer diameter surface of the hub wheel, and an inner diameter side toward the outer peripheral surface of the hub wheel. The axial contact lip has a surface contact area on the tip inner diameter surface that makes surface contact with the hub wheel or the slinger mounted on the outer diameter surface of the hub wheel. 1. A sealing device, comprising: a recessed portion for reducing a contact area with a hub wheel or a slinger attached to an outer diameter surface of a hub wheel, leaving an annular surface contact area on an inner diameter side. 2. The sealing device according to claim 1, wherein the recesses are arranged intermittently in the circumferential direction of the axial contact lip. 3. A sealing device according to claim 1, wherein said recessed portion is a through hole penetrating said axial contact lip from the inner diameter side to the outer diameter side. The sealing device according to claim 1 or 2, wherein the recessed portion is formed in an annular groove shape. A wheel bearing device equipped with the sealing device according to any one of claims 1 to 4.

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