JP2019094977A - Sealing device - Google Patents

Abstract

To provide a sealing device which can inhibit mud water etc. from touching an outer ring.SOLUTION: A sealing device is provided at an axial end part of a rolling bearing 10 having an outer ring 11 and an inner ring 12 and includes: a first seal member 21 having a core material 25 attached to an inner peripheral surface 11a of the outer ring 11 and having an elastic member 26 adhered to the core material 25 and including a first lip part 26a; a slinger 23 which is attached to the inner ring 12 and with which the first lip part 26a contacts; and a second seal member 22 having a core material 28 attached to an outer peripheral surface 11b of the outer ring 11 and covering an axial end surface 11d of the outer ring 11 and an elastic member 29 adhered to the core material 28. The elastic member 29 of the second seal member 22 includes a second lip part 29b which covers a border part 11e between the axial end surface 11d and the inner peripheral surface 11a of the outer ring 11.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sealing device applied to a rolling bearing such as a hub unit.

  Patent Document 1 below discloses a sealing device used for a hub unit (bearing device for an axle) of a vehicle. This sealing device includes a seal member fixed to the inner peripheral surface of the outer ring at both axial ends of the rolling bearing and a slinger fixed to the outer peripheral surface of the inner ring, and brings the lip portion of the seal member into contact with the slinger. Thus, the lubricant in the rolling bearing is prevented from leaking while preventing the entry of foreign matter such as mud from the outside. Further, Patent Document 1 discloses a second seal member attached to the outer peripheral surface of the outer ring. The second seal member is provided with a lip portion in contact with an externally attached slinger attached to the inner ring to prevent mud water or the like from being directly applied to the first seal member.

JP, 2009-197975, A

In the technique described in Patent Document 1, the infiltration of muddy water or the like into the rolling bearing can be more reliably prevented by providing not only the first seal member but also the second seal member.
However, once muddy water or the like enters the second seal member, the muddy water or the like is difficult to be discharged to the outside, and muddy water or the like easily remains in the second seal member. In the second seal member, the boundary between the inner peripheral surface of the outer ring to which the first seal member is attached and the axial end face of the outer ring to which the second seal member is attached is by the first and second seal members Since it is not covered and is exposed, mud water or the like is touched and rusting occurs, and this rust may progress along the inner circumferential surface of the outer ring and reach the inside of the rolling bearing.

  An object of this invention is to provide the sealing device which can suppress that mud water etc. touch an outer ring | wheel.

The present invention
A sealing device provided at an axial end of a rolling bearing having an outer ring and an inner ring, the sealing device comprising:
A core material attached to the inner peripheral surface of the outer ring, and a first seal member having an elastic member bonded to the core material and including a first lip portion;
A slinger attached to the inner ring and in contact with the first lip portion;
A core member attached to an outer peripheral surface of the outer ring and covering an axial end surface of the outer ring, and a second seal member having an elastic member bonded to the core member;
The elastic member of the second seal member includes a second lip that covers the boundary between the axial end surface and the inner peripheral surface of the outer ring.

  According to the sealing device of the above configuration, since the second seal member includes the second lip portion covering the boundary between the axial end surface of the outer ring and the inner circumferential surface, muddy water or the like is in contact with the boundary. It becomes difficult, and it can prevent that rust advances from the said boundary part and reaches inside of a rolling bearing.

Preferably, the second lip is in contact with the first seal member.
With such a configuration, it is possible to reliably prevent muddy water or the like from coming into contact with the boundary between the axial end surface and the inner circumferential surface of the outer ring. In addition, since the second lip and the first seal member are both fixed to the outer ring and do not rotate relative to each other, the rolling resistance of the rolling bearing increases with the contact between the two, and the second lip wears. There is almost no need to

Preferably, the second lip is in contact with the elastic member of the first seal member.
With such a configuration, the sealability can be enhanced as compared to the case where the second lip portion contacts metal.

Preferably, the elastic member of the second seal member further includes a third lip portion, and the third lip portion is disposed with a gap from a sealed surface opposite to the third lip portion. .
With such a configuration, the labyrinth seal can be formed by the third lip portion, and the increase in the rotational resistance of the rolling bearing can be suppressed.

  According to the present invention, it is possible to prevent mud water or the like from touching the outer ring.

It is a sectional view of a rolling bearing to which a sealing device concerning an embodiment is applied. It is sectional drawing which expands and shows a sealing device. It is sectional drawing which expands and shows the 2nd lip | rip part of the 2nd sealing member of a natural state.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.
FIG. 1 is a cross-sectional view of a rolling bearing to which a sealing device according to an embodiment is applied.
The rolling bearing 10 is a double-row rolling bearing applied to a hub unit, and includes a pair of races 11 and 12, a rolling element 13, and a cage 14.

The pair of races comprises an outer ring 11 and an inner ring 12 disposed radially inward of the outer ring 11.
The outer ring 11 is formed in an annular shape, and double rows of raceway surfaces 11a1 are formed on the inner circumferential surface 11a. Each raceway surface 11a1 is formed in a tapered shape in which the inner diameter increases in the axial direction. The outer peripheral surface 11b of the outer ring 11 is provided with a flange portion 11c attached to a knuckle on the vehicle body side.

The inner ring 12 is provided in line in the axial direction. A raceway surface 12a1 facing the raceway surface 11a1 of the outer ring 11 is formed on the outer peripheral surface 12a of each inner ring 12. The raceway surface 12a1 of the inner ring 12 is formed in a tapered shape in which the outer diameter increases in the axial direction.
On both axial sides of the raceway surface 12a1 of the inner ring 12, a large rib portion 12c and a small rib portion 12d for guiding the rolling element 13 are provided. A hub ring (not shown) having a flange portion for attaching a wheel is inserted into the inner circumferential surface 12 b of the inner ring 12. The rolling bearing 10 rotatably supports the hub wheel.

  A plurality of rolling elements 13 are provided between the raceway surface 11 a 1 of the outer ring 11 and the raceway surface 12 a 1 of the inner ring 12 at intervals in the circumferential direction. The rolling element 13 of this embodiment is a tapered roller. The plurality of rolling elements 13 are circumferentially held by the cage 14.

  Sealing devices 20 are provided at both axial ends of the rolling bearing 10. Hereinafter, the sealing device 20 on one axial side (right side in FIG. 1) will be described in detail.

FIG. 2 is a cross-sectional view showing the sealing device 20 in an enlarged manner.
The sealing device 20 prevents the lubricant sealed inside the rolling bearing 10 from leaking to the outside, and prevents the entry of mud water or the like from the outside into the rolling bearing 10. The sealing device 20 includes a first seal member 21 attached to the inner circumferential surface 11 a of the outer ring 11, a slinger 23 attached to the outer circumferential surface 12 a of the inner ring 12, and a second attached to the outer circumferential surface 11 b of the outer ring 11. And the seal member 22 of FIG.

  The first seal member 21 has a core 25 and an elastic member 26. The core material 25 is metal, such as a cold-rolled steel plate or a stainless steel plate, and is formed in a substantially L-shaped cross section. Specifically, the core member 25 is bent radially inward from the end of the cylindrical portion 25a formed in a cylindrical shape and the axial direction inner side (the inner side of the rolling bearing 10; the left side in FIG. 2) of the cylindrical portion 25a. And an annular portion 25b. The first seal member 21 is fixed to the outer ring 11 by fitting the outer peripheral surface 25 a 1 of the cylindrical portion 25 a to the inner peripheral surface 11 a of the outer ring 11.

  The elastic member 26 is formed of nitrile rubber or the like, and is mainly adhered by vulcanization to the inner peripheral surface 25a2 of the cylindrical portion 25a of the core material 25 and the axial outer surface 25b1 of the annular portion 25b. The elastic member 26 has a first lip 26a. The first lip portion 26a includes a pair of radial lips 26a1 and 26a2 and an axial lip 26a3.

  The slinger 23 is made of a metal such as a cold-rolled steel plate or a stainless steel plate, and has a substantially L-shaped cross section. Specifically, the slinger 23 is bent radially outward from the end of the cylindrical portion 23a formed in a cylindrical shape and the axial outer side (the outer side of the rolling bearing 10; right side in FIG. 2) of the cylindrical portion 23a. And an annular portion 23b. The slinger 23 is fixed to the inner ring 12 by fitting the inner peripheral surface 23 a 1 of the cylindrical portion 23 a to the outer peripheral surface 12 a of the inner ring 12. The radial lips 26a1 and 26a2 of the elastic member 26 are in contact with the outer peripheral surface 23a2 of the cylindrical portion 23a of the slinger 23. Further, an axial lip 26a3 is in contact with the axially inner side surface 23b1 of the annular portion 23b of the slinger 23.

  The second seal member 22 has a core 28 and an elastic member 29. The core member 28 is made of a metal such as a cold-rolled steel plate or a stainless steel plate, and is formed in a substantially L-shaped cross section. Specifically, the core member 28 has a cylindrical portion 28a formed in a cylindrical shape, and an annular portion 28b bent inward in the radial direction from the axial outer end of the cylindrical portion 28a.

  The second seal member 22 is fixed to the outer ring 11 by fitting the inner peripheral surface 28 a 1 of the cylindrical portion 28 a to the outer peripheral surface 11 b of the outer ring 11. In the annular portion 28b, the axially inner side surface 28b1 is in contact with the axial end face 11d of the outer ring 11, and covers the end face 11d. Therefore, the annular portion 28 b of the core member 28 constitutes a “covering portion” that covers the axial end face 11 d of the outer ring 11.

  The elastic member 29 is formed of nitrile rubber or the like, and is mainly adhered to the outer peripheral surface 28a2 of the cylindrical portion 28a of the core member 28 and the side surface 28b2 on the axially outer side of the annular portion 28b by vulcanization. The elastic member 29 has a second lip 29 b and a third lip 29 c.

The second lip portion 29 b covers a boundary portion 11 e between the inner peripheral surface 11 a of the outer ring 11 and the axial end surface 11 d. The boundary portion 11 e is formed in a tapered surface.
The second lip portion 29b extends obliquely inward in the axial direction and inward in the radial direction, as also shown in FIG. The tip of the second lip 29 b is in contact with the first seal member 21.

  Specifically, one axial end surface 25a3 of the cylindrical portion 25a of the core 25 of the first seal member 21 is covered by the portion 26b of the elastic member 26, and the second lip 29b is one of the elastic members 26. It is in contact with the portion 26b. Therefore, the contact between the second lip portion 29b and the part 26b of the elastic member 26 is the contact between the elastic members. Further, as shown by a two-dot chain line in FIG. 3, the second lip portion 29 b is elastically deformed outward in the axial direction by contacting a portion 26 b of the elastic member 26.

The third lip portion 29 c obliquely extends axially outward and radially outward from the vicinity of the boundary between the cylindrical portion 28 a and the annular portion 28 b in the core member 28.
The third lip portion 29 c is disposed, for example, with a clearance s from a sealed surface 30 formed of a flange portion of a hub wheel inserted into the inner ring 12 or a slinger fixed to the inner ring 12. And forms a labyrinth seal between them.

  As shown in FIG. 1, the sealing device 20 disposed on the other axial side (left side in FIG. 1) includes the first seal member 21 and the slinger 23 described above. Not equipped. However, the second sealing member 22 may be provided also in the sealing device 20.

  The sealing device 20 of the present embodiment described above includes the second seal member 22 attached to the outer ring 11, as shown in FIG. 2, and the second seal member 22 includes the second lip portion 29b. ing. The second lip portion 29b covers the boundary portion 11e between the axial end surface 11d of the outer ring 11 and the inner circumferential surface 11a, and therefore, it is possible to suppress mud water or the like from coming into contact with the boundary portion 11e. .

  Further, since the second lip portion 29b is in contact with the first seal member 21, it is possible to reliably prevent the entry of muddy water or the like into the boundary portion 11e of the outer ring 11. Further, since the second seal member 22 and the first seal member 21 are both attached to the outer ring 11, they do not rotate relative to each other. Therefore, the second lip portion 29 b is not worn by the contact with the first seal member 21, and the second lip portion 29 b does not increase the rotational resistance of the inner ring 12.

The second lip portion 29 b is in contact with a portion 26 b of the elastic member 26 in the first seal member 21, so, for example, the axial direction one end face 25 a 3 of the metal core 25 in the first seal member 21 is The sealing performance can be enhanced as compared with the case where the second lip portion 29 b directly contacts the axial end surface 25 a 3 of the core member 25 without being covered by the portion 26 b of the elastic member 26.
In addition, the third lip 29c of the second seal member 22 does not contact the sealed surface 30, and forms a labyrinth seal with the sealed surface 30, so the third lip 29c is It does not increase the rotational resistance of the inner ring 12.

The present invention is not limited to the above embodiment, but can be modified within the scope of the invention described in the claims.
For example, the rolling bearing 10 is not limited to those provided with tapered rollers as rolling elements, and may be provided with balls, cylindrical rollers, and the like.
The second lip portion 29 b of the second seal member 22 may be disposed with a slight gap between itself and the first seal member 21. In this case, a labyrinth seal can be formed, and the contact of water with the boundary portion 11 e can be suppressed.

  In addition, the second lip portion 29 b of the second seal member 22 may be in contact with the core 25 of the first seal member 21. For example, the axial end face 25a3 of the cylindrical portion 25a of the core 25 may be exposed without being covered by the elastic member 26, and the second lip 29b may be in contact with the axial end face 25a3 of the cylindrical portion 25a.

The third lip 29 c of the second seal member 22 may be in contact with the sealed surface 30.
The number, the shape, and the like of the radial lip and the axial lip in the first lip portion 26 a of the first seal member 21 are not limited.

10: rolling bearing 11: outer ring 11a: inner circumferential surface 11b: outer circumferential surface 11d: axial end face 11e: boundary portion 12: inner ring 20: sealing device 21: first sealing member 22: second sealing member 23: slinger 26 : Elastic member 26a: First lip portion 29: Elastic member 29b: Second lip portion 29c: Third lip portion 30: Sealed surface

Claims (4)

A sealing device provided at an axial end of a rolling bearing having an outer ring and an inner ring, the sealing device comprising:
A core material attached to the inner peripheral surface of the outer ring, and a first seal member having an elastic member bonded to the core material and including a first lip portion;
A slinger attached to the inner ring and in contact with the first lip portion;
A core member attached to an outer peripheral surface of the outer ring and covering an axial end surface of the outer ring, and a second seal member having an elastic member bonded to the core member;
The elastic member of the second seal member includes a second lip that covers a boundary between an axial end surface and an inner circumferential surface of the outer ring.   The sealing device according to claim 1, wherein the second lip is in contact with the first seal member.   The sealing device according to claim 2, wherein the second lip is in contact with the elastic member of the first seal member.   The elastic member of the second seal member further includes a third lip portion, and the third lip portion is disposed with a gap from a sealed surface opposite to the third lip portion. The sealing device of any one of 1-3.

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