JP7023681B2 - Sealing device for hub unit - Google Patents

Description

The present invention relates to a sealing device used in a hub unit (bearing device for wheels).

A hub unit (wheel bearing device) that is mounted on a vehicle such as an automobile and supports wheels rotatably has an inner shaft and an outer ring arranged concentrically, and is located between the inner shaft and the outer ring. The disposed rolling element makes the inner shaft rotatable with respect to the outer ring. A flange extending radially outward is provided at the end of the inner shaft on the vehicle outer side, and wheels and brake discs are attached to this flange.

In such a hub unit, in order to prevent muddy water or the like from entering the annular space in which the rolling elements between the inner shaft and the outer ring are arranged, sealing devices are provided at both ends in the axial direction of the annular space. It is installed.

In the hub unit, as the sealing device used on the outer side of the vehicle, for example, there is one shown in FIG. This sealing device has a seal body 130 attached to the inner peripheral surface of the outer ring 103, and a slinger 131 having a cylindrical portion 131a attached to the outer peripheral surface of the inner shaft 104 and an annular portion 131c arranged on the inner surface of the flange portion 111. The lips 134a to 134c of the seal body 130 are in contact with the slinger 131 (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2017-137973

In this type of sealing device 112, it is desired to reduce the rotational resistance of the inner shaft 104 in order to reduce the rotational torque of the hub unit. One of the factors that increase the rotational resistance of the inner shaft 104 is the contact pressure of the lips 134a to 134c with respect to the slinger 131.

In the sealing device 112 shown in FIG. 5, the two side lips 134a and 134b of the sealing body 130 are in contact with the annular portion 131c of the slinger 131. Further, these side lips 134a and 134b all have the same length and thickness. Therefore, the contact pressures of the lips 134a to 134c with respect to the slinger 131 are all in a high state, and although the sealing property of the sealing device 112 is maintained, the rotational resistance of the inner shaft 104 tends to increase.

An object of the present invention is to provide a sealing device for a hub unit capable of reducing the rotational resistance of the inner shaft while ensuring the sealing property.

(1) The present invention is a sealing device for a hub unit that seals an annular space between an inner shaft and an outer ring at an end on the outer side of a vehicle.
The seal member attached to the outer ring and
Equipped with a slinger attached to the inner shaft,
The slinger has a cylindrical portion fitted to the inner shaft and an annular portion extending radially outward from the cylindrical portion.
The annular portion includes a first annular portion and a second annular portion arranged on the vehicle inner side of the first annular portion.
The sealing member includes a first side lip that contacts the vehicle inner side side surface of the first annulus portion.
A groove along the circumferential direction is formed between the first annulus portion and the second annulus portion.

In the sealing device having the above configuration, the slinger comprises a first annulus portion to which the first side lip contacts, and a second annulus portion arranged on the vehicle inner side from the first annulus portion. A groove along the circumferential direction is formed between the first annulus portion and the second annulus portion. Therefore, first, the first side lip that comes into contact with the first annulus portion can prevent foreign matter such as muddy water from entering the sealing device. Even if muddy water or the like passes between the first annulus portion and the first side lip, the second annulus portion becomes a weir, and the first annulus portion and the second annulus are formed. Muddy water or the like can be retained in the groove between the parts. Therefore, by bringing only the first side lip into contact with the first annulus portion, the rotational resistance of the inner shaft can be reduced, the rotational torque of the hub unit can be reduced, and the second annulus portion seals the inner shaft. The sealing property of the device can be ensured.

(2) Preferably, a gap forming a labyrinth seal is provided between the radial outer end portion of the second annulus portion and the inner peripheral surface of the first side lip.
With such a configuration, it is possible to effectively prevent muddy water and the like from entering the hub unit beyond the second annulus portion.

(3) Preferably, the sealing member further includes a second side lip that contacts the side surface of the second ring portion on the vehicle inner side, and the second side lip is more than the first side lip. Is also short and thin.
According to this configuration, the second side lip in contact with the second ring portion can effectively prevent muddy water and the like from entering the inside of the hub unit. Further, by bringing the second side lip into contact with the second annulus portion, the rotational resistance of the inner shaft is slightly increased, but the second side lip is formed shorter and thinner than the first side lip. Therefore, the contact pressure with respect to the second annulus portion can be reduced, and an increase in the rotational resistance of the inner shaft can be suppressed. As a result, the rotational torque of the hub unit can be reduced as compared with the conventional sealing device shown in FIG. 5, for example.

(4) Preferably, the sealing member further includes a second side lip arranged with a gap constituting the labyrinth seal with respect to the side surface of the second ring portion on the vehicle inner side.
According to this configuration, since the labyrinth seal is formed between the second annulus portion and the second side lip, it is possible to effectively prevent muddy water and the like from entering the inside of the hub unit. .. Further, since the second side lip does not come into contact with the second annulus portion, the rotational resistance of the inner shaft does not increase.

(5) Preferably, the slinger has a first partition having the first annulus portion and a second partition having the second annulus portion and connected to the first annulus portion. It has a split body.
According to this configuration, a slinger having two annulus portions can be easily manufactured.

According to the present invention, it is possible to reduce the rotational resistance of the inner shaft while ensuring the sealing property.

It is sectional drawing of the hub unit provided with the sealing device which concerns on 1st Embodiment. It is sectional drawing of the sealing device. It is sectional drawing of the sealing apparatus which concerns on 2nd Embodiment. It is sectional drawing of the sealing apparatus which concerns on 3rd Embodiment. It is sectional drawing of the sealing device which concerns on the prior art.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[Hub unit configuration]
FIG. 1 is a cross-sectional explanatory view of a hub unit (wheel bearing device) provided with a sealing device according to the first embodiment. In the present specification, the left-right direction of FIG. 1 is referred to as an axial direction, the left side of FIG. 1 is referred to as the vehicle outer side, and the right side is referred to as the vehicle inner side.

The hub unit 1 rotatably supports the wheels with respect to the suspension device 2 provided on the vehicle body of the automobile, and includes an outer ring 3 and an inner shaft 4. The outer ring 3 and the inner shaft 4 are arranged concentrically. In this embodiment, the inner shaft 4 is rotatable with respect to the outer ring 3. The hub unit 1 can rotatably support the inner shaft 4 having wheels and brake discs (not shown) fixed to the flange 11 with respect to the vehicle.

The outer ring 3 is formed in a cylindrical shape. A flange 5 is formed on the outer peripheral surface 3b of the outer ring 3. The flange 5 is fixed to the suspension device 2 on the vehicle body side by bolts 6. A double-row outer ring raceway surface 3d is formed on the inner peripheral surface of the outer ring 3.

The inner shaft 4 is composed of a shaft main body portion 7 and an inner ring member 8.
A flange 11 for attaching a wheel or a brake disc (not shown) is formed at the end of the shaft body 7 on the vehicle outer side.
The inner ring member 8 is formed in an annular shape, is fitted onto the end of the shaft main body 7 on the vehicle inner side, and is caulked and fixed.

On the outer peripheral surface of the shaft main body portion 7, an inner ring raceway surface 7a facing the inner side in the radial direction of the outer ring raceway surface 3d on the vehicle outer side is formed. On the outer peripheral surface of the inner ring member 8, an inner ring raceway surface 8a facing the inner side of the outer ring raceway surface 3d on the vehicle inner side in the radial direction is formed.
A plurality of rolling elements 9 are arranged between the outer ring raceway surface 3d and the inner ring raceway surfaces 7a and 8a in each row. The rolling element 9 of this embodiment is a ball. The plurality of balls 9 in each row are held at predetermined intervals in the circumferential direction by the cage 10.

Between both ends of the outer ring 3 in the axial direction and the inner shaft 4, more specifically, between the vehicle outer side end of the outer ring 3 and the shaft body 7, and the vehicle inner side end of the outer ring 3 and the inner ring member. Sealing devices 12 and 13, respectively, are attached between the 8 and the 8th. These sealing devices 12 and 13 prevent foreign substances such as muddy water from entering the annular space R formed between the outer ring 3 and the inner shaft 4 from the radial outside of the outer ring 3, and also prevent foreign matter such as muddy water from entering the annular space R. It has a role of preventing the lubricant from leaking. Among these sealing devices 12 and 13, the sealing device 12 arranged on the vehicle outer side (left side in FIG. 1) is the sealing device according to the embodiment of the present invention.

[Structure of sealing device]
FIG. 2 is a cross-sectional view of the sealing device 12 of FIG.
As shown in FIG. 2, the sealing device 12 includes a sealing member 30 and a slinger 31.

The slinger 31 is formed in an annular shape by pressing a hard material having a rust-resistant property, for example, a metal plate such as stainless steel.
The slinger 31 has first and second cylindrical portions 31a and 31b, and first and second annular portions 31c and 31d.

The first cylindrical portion 31a is fixed to the shaft main body portion 7 by being fitted to the outer peripheral surface 7b of the shaft main body portion 7 (inner shaft 4). The first cylindrical portion 31a exhibits a double structure by being folded back at an end portion on the vehicle inner side, and has an inner peripheral portion 31a1 and an outer peripheral portion 31a2.

The first annular portion 31c extends radially outward from the end of the inner peripheral portion 31a1 of the first cylindrical portion 31a on the vehicle outer side along the side surface (flange surface 11a) of the flange 11 on the vehicle inner side. ing.
The second cylindrical portion 31b bends from the radial outer end portion of the first annular portion 31c toward the outer ring 3 side and extends toward the vehicle inner side.

The second annular portion 31d extends radially outward from the end of the outer peripheral portion 31a2 of the first cylindrical portion 31a on the vehicle outer side. The second annular portion 31d is arranged on the vehicle inner side of the first annular portion 31c. Further, the second annular portion 31d is formed shorter in the radial direction than the first annular portion 31c. A groove 31e extending along the circumferential direction is formed between the first annular portion 31c and the second annular portion 31d.

The seal member 30 has a core material 32 and an elastic member 33.
The core material 32 is formed in an annular shape by pressing a steel plate such as SPCC. The core material 32 is fixed to the outer ring 3 by being fitted to the inner peripheral surface 3a of the vehicle outer side end portion of the outer ring 3.

The core material 32 has a cylindrical portion 32a, an outer ring portion 32b, an inclined portion 32c, and an inner ring portion 32d.
The cylindrical portion 32a is fitted to the inner peripheral surface 3a of the vehicle outer side end portion of the outer ring 3.
The outer ring portion 32b extends radially outward from the end portion of the cylindrical portion 32a on the vehicle outer side, and is in contact with the vehicle outer side end surface 3c of the outer ring 3.

The inclined portion 32c extends from the end portion of the cylindrical portion 32a on the vehicle inner side while being slightly inclined inward on the vehicle outer side and in the radial direction. An elastic member is filled in the concave portion between the inclined portion 32c and the cylindrical portion 32a.
The inner ring portion 32d extends radially inward from the radial inner end portion of the inclined portion 32c. The inner ring portion 32d is arranged on the vehicle inner side with respect to the outer ring portion 32b.

The elastic member 33 is formed in an annular shape by nitrile rubber or the like. The elastic member 33 is bonded to the core material 32 by vulcanization. The elastic member 33 has a plurality of lips 34a to 34c and a deflector 37.
The plurality of lips 34a to 34c include two first and second side lips (axial lips) 34a, 34b and one radial lip 34c.

The first and second side lips 34a and 34b are arranged side by side in the radial direction. The first side lip 34a arranged on the outer side in the radial direction extends from the inner ring portion 32d of the core material 32 toward the vehicle outer side. The tip of the first side lip 34a is in contact with the side surface of the first annular portion 31c of the slinger 31 on the vehicle inner side. The first side lip 34a is arranged with a minute gap 36 between the second annular portion 31d of the slinger 31 and the radial outer end portion. The gap 36 constitutes a labyrinth seal. The gap 36 can be set, for example, in the range of 0.1 mm to 5.0 mm.

The second side lip 34b arranged radially inside extends from the inner ring portion 32d of the core material 32 toward the vehicle outer side. The tip of the second side lip 34b is in contact with the side surface of the second annular portion 31d of the slinger 31 on the vehicle inner side. The second side lip 34b is formed shorter and thinner than the first side lip 34a. Therefore, the second side lip 34b has a smaller volume and lower rigidity than the first side lip 34a. Therefore, the contact pressure of the second side lip 34b with respect to the second annular portion 31d is lower than the contact pressure of the first side lip 34a with respect to the first annular portion 31c.

Further, the tightening allowance t2 of the second side lip 34b with respect to the second annular portion 31d is smaller than the tightening allowance t1 of the first side lip 34a with respect to the first annular portion 31c. Again, the contact pressure of the second side lip 34b with respect to the second annular portion 31d is lower than the contact pressure of the first side lip 34a with respect to the first annular portion 31c.

The radial lip 34c extends radially inward from the radial inner end portion of the inner annular portion 32d of the core material 32. The radial lip 34c is in contact with the outer peripheral surface of the outer peripheral portion 31a2 of the first cylindrical portion 31a of the slinger 31.

The deflector 37 is arranged on the outer side in the radial direction of the core material 32. The deflector 37 extends toward the vehicle inner side from the outer ring portion 32b of the core material 32 and is fitted to the outer peripheral surface 3b of the outer ring 3. A minute gap 38 is formed between the outer peripheral surface 37a of the deflector 37 and the second cylindrical portion 31b of the slinger 31, and the labyrinth seal is formed by the gap 38.

Further, in the deflector 37, the end surface 37b on the vehicle outer side is arranged with a minute gap 39 on the side surface of the first annular portion 31c of the slinger 31 on the vehicle inner side. The labyrinth seal is also formed by the gap 39. Therefore, the labyrinth seal by the gaps 38 and 39 prevents foreign matter such as muddy water from entering between the slinger 31 and the seal member 30 from the outside.

Further, in the sealing device 12, since the first side lip 34a of the sealing member 30 is in contact with the first annular portion 31c of the slinger 31, muddy water or the like has infiltrated through the gaps 38 and 39 constituting the labyrinth seal. Even so, the infiltration of muddy water or the like into the hub unit 1 is prevented. Further, even if muddy water or the like passes between the first side lip 34a and the first annulus portion 31c, the slinger 31 is provided with the second annulus portion 31d, so that the second annulus portion 31d is provided. The annulus portion 31d functions as a weir, and muddy water or the like can be retained in the groove 31e between the first annulus portion 31c and the second annulus portion 31d.

Since a gap 36 forming a labyrinth seal is formed between the radial outer end portion of the second annular portion 31d and the inner peripheral surface of the first side lip 34a, the gap 36 is filled with muddy water. Etc. can be prevented from passing through, and muddy water or the like can be effectively prevented from entering the hub unit 1. Even if muddy water or the like infiltrates through the gap 36 constituting the labyrinth seal, the seal member 30 is further provided with a second side lip 34b that comes into contact with the second annular portion 31d. It is possible to prevent the ingress of muddy water and the like.

Further, since the contact pressure of the second side lip 34b with respect to the second annular portion 31d is lower than the contact pressure of the first side lip 34a with respect to the first annular portion 31c, the contact pressure between the two. The rotational resistance of the inner shaft 4 can be made smaller than that in the case where is equivalent. Therefore, the rotational torque of the hub unit 1 can be reduced.

[Second Embodiment]
FIG. 3 is a cross-sectional view of the sealing device according to the second embodiment.
In this embodiment, the structure of the slinger 31 is different from that of the first embodiment.
The slinger 31 of the present embodiment is composed of two divided bodies 31A and 31B. Specifically, the slinger 31 is a first divided body 31A in which an inner peripheral portion 31a1 of the first cylindrical portion 31a, a first annular portion 31c, and a second cylindrical portion 31b are integrally formed. And the second divided body 31B in which the outer peripheral portion 31a2 of the first cylindrical portion 31a and the second annular portion 31d are integrally formed. Then, the outer peripheral portion 31a2 of the first cylindrical portion 31a in the second split body 31B is fitted to the outer peripheral surface of the inner peripheral portion 31a1 of the first cylindrical portion 31a in the first split body 31A. The first divided body 31A and the second divided body 31B are connected to each other.

In the first embodiment described above, since the first cylindrical portion 31a has a double structure due to folding, it may be difficult to process. However, in the present embodiment, the slinger 31 is divided into two parts. Since it is composed of 31A and 31B, the structure of each of the divided bodies 31A and 31B can be simplified, and the slinger 31 can be easily manufactured.

[Third Embodiment]
FIG. 4 is a cross-sectional view of the sealing device according to the third embodiment.
In the present embodiment, the structure of the second side lip 34b of the seal member 30 is different from that of the first embodiment.
The second side lip 34b of the present embodiment is not in contact with the second annulus portion 31d of the slinger 31, and a gap 40 constituting the labyrinth seal is opened between the second side lip 34b and the second annulus portion 31d. Have been placed. The dimension of the gap 40 can be set in the range of, for example, 0.1 mm to 1.0 mm.

Therefore, in the present embodiment, the contact pressure of the second side lip 34b with respect to the second annular portion 31d becomes substantially zero, and the rotational resistance of the inner shaft 4 can be made smaller.
Further, since the gap 40 constituting the labyrinth seal is formed between the second side lip 34b and the second annulus portion 31d, it is possible to effectively prevent the intrusion of muddy water and the like.

The present invention is not limited to the above embodiment, and the design can be appropriately modified within the scope of the invention described in the claims.
For example, in the above embodiment, the sealing member 30 includes the second side lip 34b, but this can be omitted.
Further, a labyrinth seal may not be formed between the radial outer end portion of the second annular portion 31d of the slinger 31 and the inner peripheral surface of the first side lip 34a.

Further, the deflector 37 in the seal member 30 and the second cylindrical portion 31b in the slinger 31 can be omitted or changed in shape.

1: Hub unit 3: Outer ring 4: Inner shaft 12: Sealing device 30: Sealing member 31: Slinger 31a: First cylindrical portion 31c: First annular portion 31d: Second annular portion 31e: Groove 33: Elastic member 34a: First side lip 34a: Second side lip 36: Gap 40: Gap t1: Tightening allowance t2: Tightening allowance

Claims (4)

A sealing device for a hub unit that seals the annular space between the inner shaft and the outer ring at the end on the outer side of the vehicle.
The seal member attached to the outer ring and
Equipped with a slinger attached to the inner shaft,
The slinger has a cylindrical portion fitted to the inner shaft and an annular portion extending radially outward from the cylindrical portion.
The annular portion includes a first annular portion and a second annular portion arranged on the vehicle inner side of the first annular portion.
A core material in which the sealing member has a cylindrical portion fitted to the inner peripheral surface of the outer ring and an inner ring portion provided radially inward from the cylindrical portion, and a vehicle from the inner ring portion. A first side lip that extends toward the outer side and comes into contact with the first annulus portion radially inward from the outer ring of the side surface of the first annulus portion on the vehicle inner side, and the second annulus portion. Includes a second side lip that contacts the vehicle inner side of the annulus
The second annulus portion is located between the first annulus portion and the inner annulus portion in the axial direction and is located radially inward of the first side lip, and the second annulus portion is located. A gap forming a labyrinth seal is provided between the radial outer end portion of the annulus portion and the inner peripheral surface of the first side lip.
A sealing device for a hub unit in which a groove along the circumferential direction is formed between the first annulus portion and the second annulus portion. The sealing device for a hub unit according to claim 1, wherein the second side lip is formed shorter and thinner than the first side lip. A sealing device for a hub unit that seals the annular space between the inner shaft and the outer ring at the end on the outer side of the vehicle.
The seal member attached to the outer ring and
Equipped with a slinger attached to the inner shaft,
The slinger has a cylindrical portion fitted to the inner shaft and an annular portion extending radially outward from the cylindrical portion.
The annular portion includes a first annular portion and a second annular portion arranged on the vehicle inner side of the first annular portion.
A core material in which the sealing member has a cylindrical portion fitted to the inner peripheral surface of the outer ring and an inner annulus portion provided radially inward from the cylindrical portion, and a vehicle from the inner annulus portion. The first side lip that extends toward the outer side and comes into contact with the first annulus portion radially inward from the outer ring of the side surface of the first annulus portion on the vehicle inner side, and the second annulus portion. Including a second side lip arranged with a gap constituting the labyrinth seal with respect to the side surface of the annulus on the vehicle inner side.
The second annulus portion is located between the first annulus portion and the inner annulus portion in the axial direction and is located radially inward of the first side lip.
A sealing device for a hub unit in which a groove along the circumferential direction is formed between the first annulus portion and the second annulus portion. The slinger has a first split body having the first annular portion and a second split body having the second annular portion and connected to the first split body. The sealing device for a hub unit according to any one of claims 1 to 3 .

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