JP2022128123A - Bearing device for wheel - Google Patents

Abstract

To provide a bearing device for a wheel which can easily drain mud water entering an interior of a labyrinth seal of a sealing device.SOLUTION: An outer side seal member 10 of a bearing device 1 for a wheel includes: a core grid 11 fitted in an outer ring 2; a seal member 12 joined to the core grid 11 and having a first side lip 12b which faces a wheel attaching flange 3b with a gap formed therebetween, and a second side lip 12c which faces a metallic ring 13 with a gap formed therebetween; and the metallic ring 13 fitting in a base part 3d of the wheel attaching flange 3b and having a circular disc part 13a which faces the second side lip, and a protruding part 13d which faces the seal member 12 with a gap formed therebetween in between the first side lip 12b and the second side lip 12c. The first side lip 12b, the second side lip 12c, and the protruding part 13d are overlapped when viewed from a radial direction. The seal member 12 includes a drain part 12A in which at least one of the first side lip 12b and the second side lip 12c is missing.SELECTED DRAWING: Figure 3

Description

The present invention relates to a wheel bearing device.

2. Description of the Related Art Conventionally, there has been known a wheel bearing device that rotatably supports a wheel in a suspension system of an automobile or the like. A wheel bearing device is provided with a sealing device that closes an open end of an annular space formed by an outer member and an inner member to prevent foreign matter such as muddy water from entering.

For example, the sealing device disclosed in Patent Document 1 includes a core bar fitted to the inner circumference of an outer ring that is an outer member, a seal member integrally joined to the core bar and having a plurality of seal lips, A disc portion fitted to the base of a wheel mounting flange formed on a hub wheel, which is an inner member, and in close contact with the side surface of the wheel mounting flange, and an axial direction from the outer diameter portion of the disc portion to the wheel mounting flange. and a metal ring having a bent portion that bends toward the spaced apart side.

A complex labyrinth seal is formed by the plurality of seal lips of the seal member and the bent portion of the metal ring positioned between the plurality of seal lips in the radial direction to suppress the intrusion of muddy water into the sealing device. ing.

JP 2017-48809 A

However, in a configuration in which a complicated labyrinth seal is formed as in the sealing device described in Patent Document 1, once muddy water enters the inside of the labyrinth seal, it is difficult to drain to the outside. If the labyrinth seal is left with muddy water intruding for a long time, the muddy water that dries up accelerates wear of the seal lip, resulting in a decrease in muddy water resistance performance.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bearing assembly for a wheel that can easily drain muddy water that has entered the inside of the labyrinth seal even when the labyrinth seal is formed in the sealing device. It is.

That is, the wheel bearing device has an outer member having a double-row outer raceway surface on the inner circumference, a wheel mounting flange for mounting a wheel on one axial end, and a small diameter stage extending axially on the outer circumference. and at least one inner ring press-fitted into the small-diameter stepped portion of the hub wheel, the inner member having double-row inner raceway surfaces facing the double-row outer raceway surfaces; One axial end side of an annular space formed by a double-row rolling element rollably accommodated between the raceway surfaces of the outer member and the inner member, and the outer member and the inner member a sealing device for closing an open end, wherein the sealing device includes a core bar fitted to the inner periphery of the outer member on one axial end side; and the core bar is integral with the core bar. and a metal ring fitted to the base of the wheel mounting flange of the inner member, wherein the sealing member extends from the core metal toward the wheel mounting flange side, and the A first seal lip that faces the wheel mounting flange with a gap therebetween, and a second seal that extends radially inward of the first seal lip from the metal core toward the wheel mounting flange side and faces the metal ring with a gap. The metal ring includes a disk portion that contacts the base portion of the wheel mounting flange and faces the second seal lip, and a radially outer end portion of the disk portion toward the core metal side. and a projecting portion facing the sealing member with a gap between the first sealing lip and the second sealing lip in the radial direction, and the first sealing lip and the second sealing lip The seal member has a drain portion in which at least one of the first seal lip and the second seal lip is missing in a predetermined region in the circumferential direction.

According to the present invention, muddy water that has entered the inside of the sealing device is easily discharged to the outside of the sealing device through the drain portion.

It is a side sectional view showing a bearing device for wheels. FIG. 4 is a side cross-sectional view showing an outer side seal member in a region where a drain portion is not formed; It is a figure which shows the outer side sealing member seen from the outer side in an axial direction. FIG. 4 is a side cross-sectional view showing an outer side seal member in a region where a drain portion is formed; It is a cross-sectional side view showing the drain portion in which only the first side lip is not formed and the second side lip is formed. It is a side cross-section showing the drain portion in which only the second side lip is not formed and the first side lip is formed. FIG. 10 is a view of the seal member, viewed from the outer side in the axial direction, in which the length of the drain portion in the circumferential direction is configured to decrease from the radially inner side to the radially outer side;

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments for carrying out the present invention will be described below with reference to the accompanying drawings.

[Wheel bearing device]
A wheel bearing device 1 shown in FIG. 1 is an embodiment of a wheel bearing device according to the present invention, and is for rotatably supporting a wheel in a suspension device of a vehicle such as an automobile.

The wheel bearing device 1 has a configuration called a third generation, and includes an outer ring 2 as an outer member, a hub wheel 3 and an inner ring 4 as inner members, and two rows of inner rings as rolling trains. It has a side ball row 5, an outer side ball row 6, an inner side seal member 9 and an outer side seal member 10. - 特許庁

Here, the inner side indicates the vehicle body side of the wheel bearing device 1 when attached to the vehicle body, and the outer side indicates the wheel side of the wheel bearing device 1 when attached to the vehicle body. Further, the lower side of the wheel bearing device 1 when attached to the vehicle body is referred to as the road surface side, and the upper side thereof is referred to as the anti-road surface side. Further, the axial direction means the direction along the rotation axis of the wheel bearing device 1, one axial end side is the outer side, and the other axial end side is the inner side.

An inner-side opening 2a into which an inner-side seal member 9 can be fitted is formed at the inner-side end of the outer ring 2 . An outer-side opening 2b into which an outer-side sealing member 10 can be fitted is formed at the outer-side end of the outer ring 2 . An inner raceway surface 2c on the inner side and an outer raceway surface 2d on the outer side are formed on the inner peripheral surface of the outer ring 2 .

A vehicle body mounting flange 2e for mounting the outer ring 2 to a vehicle body member is integrally formed on the outer peripheral surface of the outer ring 2 . The vehicle body attachment flange 2e is provided with a bolt hole 2g into which a fastening member (here, a bolt) for fastening the vehicle body side member and the outer ring 2 is inserted.

A small-diameter stepped portion 3a having a diameter smaller than that of the outer end portion is formed at the inner end portion of the outer peripheral surface 3j of the hub wheel 3. As shown in FIG. A shoulder portion 3e is formed at the outer end portion of the small-diameter stepped portion 3a of the hub wheel 3. As shown in FIG. A wheel mounting flange 3b for mounting a wheel is integrally formed on the outer side end of the hub wheel 3. As shown in FIG. A plurality of bolt holes 3f are formed in the wheel mounting flange 3b. A hub bolt 3i is press-fitted into the bolt hole 3f for fastening the hub wheel 3 and a wheel or brake component.

An outer-side inner raceway surface 3 c is provided on the outer peripheral surface 3 j of the hub wheel 3 so as to face the outer-side outer race surface 2 d of the outer ring 2 . That is, the inner raceway surface 3c is formed by the hub wheel 3 on the outer side of the inner member. The outer-side seal member 10 is fitted into the outer-side open end of the annular space formed by the outer ring 2 and the hub wheel 3 to block the outer-side open end. The outer side sealing member 10 is an example of a sealing device. The hub wheel 3 has an outer side end face 3g at an end on the outer side of the wheel mounting flange 3b.

An inner ring 4 is provided on the small diameter step portion 3 a of the hub wheel 3 . The inner ring 4 is fixed to the small-diameter stepped portion 3a of the hub wheel 3 by press-fitting and caulking. The inner ring 4 applies preload to the inner ball row 5 and the outer ball row 6, which are rolling rows. The inner ring 4 has an inner side end surface 4b at the inner side end portion and an outer side end surface 4c at the outer side end portion. The hub wheel 3 has an inner side end portion formed with a crimped portion 3h which is crimped to the inner side end face 4b of the inner ring 4. As shown in FIG.

An inner raceway surface 4 a is provided on the outer peripheral surface of the inner ring 4 so as to face the inner raceway surface 2 c of the outer ring 2 . That is, the inner raceway surface 4a is formed by the inner ring 4 on the inner side of the inner member.

The inner ball row 5 and the outer ball row 6, which are rolling rows, are formed by holding a plurality of balls 7, which are rolling elements, by a retainer 8. As shown in FIG. The inner ball row 5 is rotatably sandwiched between the inner raceway surface 4a of the inner ring 4 and the outer raceway surface 2c of the outer ring 2 on the inner side. The outer-side ball row 6 is rollably sandwiched between the inner raceway surface 3c of the hub wheel 3 and the outer-side raceway surface 2d of the outer ring 2 . That is, the inner ball row 5 and the outer ball row 6 are housed so as to roll freely between the raceway surfaces of the outer member and the inner member.

In the wheel bearing device 1, the outer ring 2, the hub ring 3, the inner ring 4, the inner ball train 5, and the outer ball train 6 constitute a double row angular contact ball bearing. Note that the wheel bearing device 1 may constitute a double-row tapered roller bearing instead of the double-row angular contact ball bearing.

[Outer side seal member]
As shown in FIG. 2, the outer side seal member 10 includes a core metal 11 fitted to the inner periphery of the outer ring 2 on the outer side, a seal member 12 integrally joined to the core metal 11, and a hub wheel 3. and a metal ring 13 fitted to the base portion 3d of the wheel mounting flange 3b.

The core bar 11 is made of, for example, a steel plate, and has a cylindrical fitting portion 11a fitted to the inner periphery of the outer opening 2b of the outer ring 2, and a fitting portion 11a extending from the inner side end of the fitting portion 11a to the inner diameter side. and an outer portion 11c extending radially outward from the outer end of the fitting portion 11a. The outer portion 11 c extends radially outward from the fitting portion 11 a and then bends toward the inner side along the outer peripheral surface of the outer ring 2 .

The seal member 12 is made of an elastic member such as synthetic rubber, and is joined to the core metal 11 by vulcanization adhesion. The seal member 12 has a base portion 12a, a first side lip 12b, a second side lip 12c, a third side lip 12d, and a radial lip 12e. The base portion 12a is joined to a range from the inner portion 11b of the metal core 11 to the outer portion 11c via the fitting portion 11a.

The first side lip 12b extends from the outer portion 11c of the core metal 11 toward the wheel mounting flange 3b, which is the outer side, and faces the inner side surface of the base portion 3d of the wheel mounting flange 3b with a gap in the axial direction. ing. A tip surface of the first side lip 12b facing the base portion 3d of the wheel mounting flange 3b is formed into a flat surface facing in the axial direction. The first side lip 12b is an example of a first seal lip.

The second side lip 12c extends radially inward of the first side lip 12b from the metal core 11 toward the wheel mounting flange 3b on the outer side. Specifically, the second side lip 12c extends from the inner portion 11b of the core bar 11 toward the wheel mounting flange 3b side and radially outward. Also, the second side lip 12c faces the metal ring 13 with a gap therebetween. The second side lip 12c is an example of a second seal lip.

The third side lip 12d extends radially inward of the second side lip 12c from the metal core 11 toward the wheel mounting flange 3b on the outer side. Specifically, the third side lip 12d extends from the inner portion 11b of the core metal 11 toward the wheel mounting flange 3b and radially outward. Also, the third side lip 12 d is in sliding contact with the metal ring 13 .

The radial lip 12e extends radially inward from the metal core 11 radially inward of the third side lip 12d. Specifically, the radial lip 12e extends radially inward and toward the inner side from the inner portion 11b of the cored bar 11 . Also, the radial lip 12 e is in sliding contact with the metal ring 13 .

The metal ring 13 is made of, for example, a steel plate, and has a disc portion 13a, a cylindrical portion 13b, a connecting portion 13c, and a projecting portion 13d. The disk portion 13a is formed in a disk shape and contacts the inner side surface of the base portion 3d of the wheel mounting flange 3b. The disk portion 13a faces the second side lip 12c with a gap in the axial direction.

The cylindrical portion 13b is formed in a cylindrical shape, and is fitted to the outer peripheral surface 3j of the hub wheel 3 on the inner side of the wheel mounting flange 3b. The cylindrical portion 13b faces the radial lip 12e in the radial direction, and the cylindrical portion 13b and the radial lip 12e are in sliding contact. The connecting portion 13c connects the disk portion 13a and the cylindrical portion 13b. The connecting portion 13c faces the third side lip 12d in the axial direction, and the connecting portion 13c and the third side lip 12d are in sliding contact.

The protruding portion 13d protrudes from the radially outer end portion of the disk portion 13a toward the metal core 11 side, which is the inner side. The projecting portion 13d is located between the first side lip 12b and the second side lip 12c in the radial direction. The projecting portion 13d faces the base portion 12a of the sealing member 12 with a gap between the first side lip 12b and the second side lip 12c in the radial direction. An elastic member 14 is integrally joined to the outer peripheral surface of the projecting portion 13d. The elastic member 14 is made of synthetic rubber, for example.

In the outer side seal member 10 configured as described above, the first side lip 12b and the second side lip 12c of the seal member 12 and the projecting portion 13d of the metal ring 13 overlap each other when viewed from the radial direction. The first side lip 12b, the second side lip 12c, and the projecting portion 13d constitute a labyrinth seal.

The first side lip 12b, the second side lip 12c, and the projecting portion 13d are positioned on the outer peripheral portion of the outer side seal member 10, and the first side lip 12b, the second side lip 12c, and the projecting portion 13d form a labyrinth. Intrusion of muddy water into the outer side seal member 10 is suppressed by configuring the seal.

In this way, when the labyrinth seal is formed in the outer-side seal member 10 to suppress the intrusion of muddy water, once muddy water enters the labyrinth seal, it tends to be difficult to drain. Therefore, in the outer side seal member 10, the seal member 12 is formed with a drain portion 12A so that even if muddy water enters the labyrinth seal, the muddy water can be easily drained.

[Drain part]
As shown in FIG. 3, the drain portion 12A is formed in a predetermined region in the circumferential direction on the road surface side of the seal member 12. As shown in FIG. In the case of this embodiment, the drain portion 12A is positioned at the lowest portion of the seal member 12 and is formed in an area of about 1/4 of the length of the seal member 12 in the circumferential direction. The length of the drain portion 12</b>A in the circumferential direction increases from the radially inner side to the radially outer side of the seal member 12 .

As shown in FIGS. 3 and 4, the first side lip 12b and the second side lip 12c are not formed in the region where the drain portion 12A of the seal member 12 is formed. That is, in the drain portion 12A of the seal member 12, the first side lip 12b and the second side lip 12c are missing, and the projecting portion 13d and the seal member 12 are located outside the third side lip 12. On the radial side, they do not overlap when viewed from the radial direction.

By configuring the drain portion 12A in the seal member 12 in this manner, even if muddy water enters the outer side seal member 10, the centrifugal force generated when the hub wheel 3 rotates with respect to the outer ring 2 causes the infiltration. The resulting muddy water is easily discharged to the outside of the outer side seal member 10 through the drain portion 12A. Muddy water discharged to the outside through the drain portion 12A passes between the projecting portion 13d of the metal ring 13 and the base portion 12a of the sealing member 12 without being blocked by the second side lip 12c and the first side lip 12b. It is easily discharged to the outside of member 12 .

As a result, the muddy water that has entered the outer side seal member 10 does not dry out while remaining in the inside, and the dry mud causes the seal lips such as the first side lip 12b and the second side lip 12c to become damaged. Abrasion can be suppressed, and the muddy water resistance of the outer side seal member 10 can be maintained for a long period of time.

In the present embodiment, the drain portion 12A is located in the lower half portion of the outer side seal member 10, which is the portion on the side of the road surface. It can also be configured. Even when the drain portion 12A is configured on the side opposite to the road surface of the outer side seal member 10, the centrifugal force generated when the hub wheel 3 rotates with respect to the outer ring 2 drains muddy water that has entered the outer side seal member 10 to the outside. can be discharged to

However, when the drain portion 12A is configured on the road surface side of the outer side seal member 10, in addition to the centrifugal force when the hub wheel 3 rotates with respect to the outer ring 2, gravitational force also causes muddy water that has entered the inside to flow outside. It is preferable to form the drain portion 12A on the road surface side of the outer side seal member 10 because the discharge of the water is facilitated.

The drain portion 12A of the outer side seal member 10 shown in FIG. 4 has a configuration in which the first side lip 12b and the second side lip 12c are not formed.

However, as shown in FIG. 5, the drain portion 12A of the outer side seal member 10 may have a configuration in which only the first side lip 12b is not formed and the second side lip 12c is formed. Also in such a configuration, the projecting portion 13d of the metal ring 13 and the sealing member 12 do not overlap with each other on the outer diameter side of the projecting portion 13d when viewed from the radial direction, so that the inside of the outer side sealing member 10 is penetrated. muddy water is easily discharged to the outside.

Further, as shown in FIG. 6, the drain portion 12A of the outer side seal member 10 may have a configuration in which only the second side lip 12c is not formed and the first side lip 12b is formed. Even in such a configuration, the projecting portion 13d of the metal ring 13 and the seal member 12 do not overlap between the first side lip 12b and the third side lip 12d when viewed in the radial direction, and the outer side seal Muddy water that has entered the inside of the member 10 is easily discharged to the outside.

Also, in the drain portion 12A of the outer side seal member 10 shown in FIG. However, as shown in FIG. 7, the drain portion 12A of the outer side seal member 10 is configured such that the length of the drain portion 12A in the circumferential direction decreases from the radially inner side to the radially outer side of the seal member 12. can also

In this way, by configuring the drain portion 12A so that the length in the circumferential direction becomes smaller as it goes radially outward, the area where the labyrinth seal is not formed becomes smaller as it goes radially outward, so that muddy water can be drained. Intrusion into the outer side seal member 10 through the portion 12A can be suppressed. This makes it possible to further improve the muddy water resistance of the outer side seal member 10 .

The wheel bearing device 1 in this embodiment is configured as a wheel bearing device 1 of a third-generation structure in which the inner raceway surface 3c is directly formed on the outer circumference of the hub wheel 3, but is limited to this. Instead, a second-generation structure in which a pair of inner rings 4 are press-fitted and fixed to the hub wheel 3 may be used.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments in any way, and is merely an example. Of course, the scope of the present invention is indicated by the description of the claims, and the meaning of equivalents described in the claims and all changes within the scope include.

1 wheel bearing device 2 outer ring 2b outer side opening 2c (inner side) outer raceway surface 2d (outer side) outer raceway surface 3 hub ring 3b wheel mounting flange 3c inner raceway surface 3d base 4 inner ring 4a inner raceway surface 5 Inner side ball row 6 Outer side ball row 10 Outer side seal member 11 Core metal 12 Seal member 12A Drain portion 12b First side lip 12c Second side lip 13 Metal ring 13a Disk portion 13d Protruding portion

Claims (3)

an outer member having a double-row outer raceway surface on its inner circumference;
It consists of a hub wheel having a wheel mounting flange for mounting a wheel on one end in the axial direction, a small diameter stepped portion extending axially on the outer periphery, and at least one inner ring press-fitted into the small diameter stepped portion of the hub wheel. an inner member having a double-row inner raceway surface facing the double-row outer raceway surface;
a double-row rolling element rollably accommodated between the raceway surfaces of the outer member and the inner member;
A wheel bearing device comprising: a sealing device for closing an open end on one axial end side of an annular space formed by the outer member and the inner member,
The sealing device is
a metal core fitted to the inner periphery of the outer member on one axial end side;
a sealing member integrally joined to the core metal;
a metal ring fitted to the base of the wheel mounting flange of the inner member;
The sealing member includes a first seal lip extending from the core metal toward the wheel mounting flange side and facing the wheel mounting flange with a gap therebetween, and a first seal lip radially inside the first seal lip from the core metal to the wheel. a second seal lip extending toward the mounting flange side and facing the metal ring with a gap;
The metal ring includes a disk portion that contacts the base portion of the wheel mounting flange and faces the second seal lip, and a radially outer end portion of the disk portion that protrudes toward the core metal side. a projecting portion facing the sealing member with a gap between the first sealing lip and the second sealing lip in
The first seal lip, the second seal lip, and the projecting portion overlap each other when viewed in a radial direction,
The wheel bearing device, wherein the seal member includes a drain portion in which at least one of the first seal lip and the second seal lip is missing in a predetermined region in the circumferential direction. 2. The wheel bearing device according to claim 1, wherein the drain portion is positioned on the road surface side portion of the seal member. 3. The wheel bearing device according to claim 1, wherein the drain portion has a circumferential length that decreases from the radially inner side to the radially outer side.

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