CN116412249A

CN116412249A - Sealing device and bearing

Info

Publication number: CN116412249A
Application number: CN202210006736.4A
Authority: CN
Inventors: 刘鑫; 张岳林; 张叶舟; 宫铭
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2022-01-05
Filing date: 2022-01-05
Publication date: 2023-07-11

Abstract

The application provides a sealing device and bearing for sealing the space between the first component and the second component that can rotate relatively, sealing device includes skeleton (1) and sealing part (2) skeleton (1) or be provided with in sealing part (2) be used for making sealing device's inboard and outside ventilate but prevent the gas passage that the pollutant passed through.

Description

Sealing device and bearing

Technical Field

The application relates to a sealing device and a bearing.

Background

As shown in fig. 1 to 3, a sealing structure of a wheel bearing includes a bearing inner ring 100, a bearing outer ring 200, rolling bodies 300, an oil seal 400, and a cartridge seal 500. The oil seal 400 and the box seal 500 are both installed between the bearing inner ring 100 and the bearing outer ring 200 in an interference manner, and the oil seal 400 and the box seal 500 are respectively located at both axial ends of the bearing. The oil seal 400 may be used to seal transmission oil and the cartridge seal 500 may be used to prevent contaminants in the environment, such as muddy water, from entering the bearings.

When the bearing rotates at a high speed for a certain period of time or the temperature of the bearing increases, for example, by a brake system, air in the bearing chamber 600 expands, resulting in an increase in air pressure, and since all sealing lips of the oil seal 400 and the cartridge seal 500 extend outward from the bearing chamber, part of the air in the bearing chamber 600 can be discharged through the sealing lips. Due to the orientation of the sealing lips, when the bearing cools, ambient air is blocked by the sealing lips from entering the bearing cavity 600, which will result in the bearing cavity 600 being in a vacuum state. Such vacuum conditions may accelerate wear of the sealing lips, affecting the bearing sealing performance and life of the sealing device.

Disclosure of Invention

The application aims at providing a sealing device to solve the defects in sealing performance and service life.

The present application proposes a sealing device for sealing a space between a first member and a second member which are relatively rotatable,

the sealing device includes a skeleton and a sealing portion in which a gas passage for ventilating the inside and the outside of the sealing device but preventing the passage of contaminants is provided.

In at least one embodiment, the gas channel comprises:

a first air hole provided in the frame or the sealing portion; and

and the waterproof and breathable material is plugged into the first air hole and/or is arranged on one side or two sides of the first air hole.

In at least one embodiment, the sealing device further comprises a flinger, the sealing portion comprising a first sealing lip as a dust lip, the first sealing lip extending from the backbone toward the flinger, a face of the flinger in contact with the first sealing lip comprising a frosted surface, the gas channel further comprising a gap between a free end of the first sealing lip and the frosted surface.

In at least one embodiment, the matte surface has a roughness between Ra0.6 μm and Ra 1.6 μm.

In at least one embodiment, the seal further includes a second seal lip as a main lip, the second seal lip extending from the backbone toward the flinger or the first member supporting the flinger, a free end of the second seal lip being in contact with the flinger or the first member,

the first seal lip, the second seal lip and the flinger, or the first seal lip, the second seal lip, the flinger and the first member enclose an annular chamber,

the chamber communicates with an axially inner side of the sealing device via the first air hole, and communicates with an axially outer side of the sealing device via a gap between the first sealing lip and the frosted surface.

In at least one embodiment, the first air hole is located between the base end of the first sealing lip and the base end of the second sealing lip, the first air hole passing through the sealing portion without passing through the backbone.

In at least one embodiment, the gas channel comprises:

a second air hole provided in the slinger or the first seal lip; and

and the waterproof and breathable material is plugged into the second air hole and/or is arranged on one side or two sides of the second air hole.

In at least one embodiment, a plurality of the first air holes are provided along a circumferential direction of the sealing device; and/or

A plurality of second air holes are arranged along the circumferential direction of the sealing device.

In at least one embodiment, the waterproof breathable material is felt.

The application also proposes a bearing comprising a sealing device according to any of the above-mentioned technical solutions.

By adopting the technical scheme, the air pressures at the two axial sides of the sealing device are balanced, so that the difference of the pressure at the two sides of the sealing device can be avoided, and the sealing performance and the service life of the sealing device can be improved.

Drawings

Fig. 1 shows one half of a schematic construction of one possible bearing.

Fig. 2 shows one half of a cross-sectional view of one possible oil seal of a bearing.

Fig. 3 shows one half of a cross-sectional view of a possible bearing cartridge seal.

FIG. 4 shows half of a schematic structural view of a bearing according to an embodiment of the present application

Fig. 5 shows half of a cross-sectional view of a cartridge sealing device of a bearing according to an embodiment of the present application.

Description of the reference numerals

100 bearing inner ring 200 bearing outer ring 300 rolling element 400 oil seal device 500 box type seal device 600 bearing cavity

1 skeleton 11 skeleton axial portion 12 skeleton radial portion

2 the waterproof and breathable material for the air holes 25 of the first sealing lip 22, the second sealing lip 23, the third sealing lip 24 of the sealing part 21

3 flinger 31 flinger axial portion 32 flinger radial portion

C chamber G opening

Aaxial R radial.

Detailed Description

To more clearly illustrate the above objects, features and advantages of the present application, specific embodiments of the present application are described in detail in this section in conjunction with the accompanying drawings. The present application can be embodied in other different forms besides the embodiments described in this section, and those skilled in the art may make corresponding modifications, variations, and substitutions without departing from the spirit of the application, so that the application is not limited to the specific examples disclosed in this section. The protection scope of the present application shall be subject to the claims.

As shown in fig. 4 and 5, the present application proposes a bearing, which may be a wheel bearing for a vehicle, for example a wheel bearing for a truck wheel. The bearing includes a bearing inner ring 100 (an example of a first member), a bearing outer ring 200 (an example of a second member), rolling elements 300, an oil seal 400, and a box seal 500, the rolling elements 300 being located between the bearing inner ring 100 and the bearing outer ring 200. The rolling elements 300 may be provided in two rows, with a bearing cavity 600 formed between the two rows of rolling elements 300, which bearing may be, for example, a double row tapered roller bearing.

The oil seal 400 and the box seal 500 are both interference-fitted between the bearing inner ring 100 and the bearing outer ring 200, the oil seal 400 being located axially outside (right end of fig. 4) of one row of rolling elements 300, and the box seal 500 being located axially outside (left end of fig. 4) of the other row of rolling elements 300. The oil seal 400 may be used to seal transmission oil and the cartridge seal 500 may be used to prevent contaminants in the environment, such as muddy water, from entering the bearings.

The axially outer side of the cartridge seal means, which is the side facing the external environment, and the axially inner side of the cartridge seal means, which is the side facing the bearing cavity 600, are opposite.

The cartridge sealing device 500 has an annular shape as a whole. The cartridge type sealing device includes a slinger 3 for fixing to the bearing inner race 100 and a seal ring for fixing to the bearing outer race 200. The seal ring includes a frame 1 and a seal portion 2, and the seal portion 2 may be attached to the frame 1. The slinger 3 and the skeleton 1 may be made of hard materials such as metal, and the seal 2 may be made of elastic materials such as rubber.

The cage 1 includes a cage axial portion 11 and a cage radial portion 12, the cage axial portion 11 extending in the axial direction a and the circumferential direction of the bearing, and the cage radial portion 12 extending in the radial direction R and the circumferential direction of the bearing. In the present embodiment, the cage axial portion 11 may be fixed to the bearing outer race 200.

Alternatively, the skeleton axial portion 11 may be connected with a skeleton stopper 13, and the skeleton stopper 13 may extend radially outward from the skeleton axial portion 11. In the present embodiment, the skeleton stopper 13 may abut against an axial end portion of the bearing outer ring 200, so that the cartridge type sealing device may be axially positioned and mounted to the bearing outer ring 200. The seal 2 may be attached to the carcass axial portion 11 and/or the carcass radial portion 12.

The slinger 3 includes a slinger axial portion 31 and a slinger radial portion 32, the slinger axial portion 31 extending in the axial direction A and the circumferential direction, and the slinger radial portion 32 extending in the radial direction R and the circumferential direction. In the present embodiment, the slinger axial portion 31 may be fixed to the bearing inner race 100.

Between the flinger radial portion 32 and the seal ring, particularly between the flinger radial portion 32 and the armature axial portion 11, on the radially outer side of the first seal lip 21 described later of the seal portion 2, there may be an opening G through which the radially outer side of the first seal lip 21 can be brought into contact with the outside.

The sealing part 2 may include a first sealing lip 21, a second sealing lip 22, and a third sealing lip 23.

The first seal lip 21 may extend from the skeleton radial portion 12 toward the slinger radial portion 32, the first seal lip 21 being inclined. The first seal lip 21 extends from the radially inner side to the radially outer side while extending from one axial side (right side in fig. 5, inner side of the seal device) to the other axial side (left side in fig. 5, outer side of the seal device). The free end of the first seal lip 21 may be in contact with the flinger radial portion 32. The first sealing lip 21 may be referred to as a dust lip.

The second seal lip 22 extends from the skeleton radial portion 12 toward the slinger axial portion 31, the second seal lip 22 is inclined toward the axially outer side and the radially inner side of the cartridge type seal, and the second seal lip 22 extends from the radially outer side toward the radially inner side while extending from one axial side (right side in fig. 5) toward the other axial side (left side in fig. 5). The free end of the second seal lip 22 may be in contact with the flinger axial portion 31. The second sealing lip 22 may be referred to as a primary lip.

A spring may be provided to press the second seal lip 22 radially inward. It is understood that the second seal lip 22 is not limited to contact with the slinger axial portion 31, and the second seal lip 22 may also contact the bearing inner race 100.

The third seal lip 23 extends from the carcass radial portion 12 toward the bearing inner ring 100, the third seal lip 23 is inclined toward the axially outer side and the radially inner side of the cartridge type sealing device, and the third seal lip 23 extends from the radially outer side toward the radially inner side while extending from the axial one side (right side in fig. 5) toward the axial other side (left side in fig. 5). The free end of the third seal lip 23 may be in contact with the bearing inner race 100. The third sealing lip 23 may be referred to as a secondary lip.

The first seal lip 21, the second seal lip 22, the flinger axial portion 31 and the flinger radial portion 32 may enclose an annular chamber C. The chamber C may communicate with the outside via a gap between the first seal lip 21 and the flinger radial part 32.

The sealing portion 2 is provided with an air hole 24 (an example of a first air hole), the air hole 24 is a through hole, one end of the air hole 24 may be communicated to the bearing chamber 600, the other end of the air hole 24 may be communicated to the chamber C, and the bearing chamber 600 is communicated with the chamber C through the air hole 24. A plurality of air holes 24 may be provided along the circumferential direction of the seal ring. Alternatively, the portion of the sealing portion 2 where the air holes 24 are formed has no skeleton 1 inside, and the air holes 24 can be made easier to process. Here, the air holes 24 may be formed in the rubber material of the sealing portion 2, in which case the air holes 24 may be formed simultaneously with vulcanization molding of the rubber material.

Alternatively, the air hole 24 may be located between the base end of the first seal lip 21 and the base end of the second seal lip 22. The air holes 24 may extend in the axial direction a. The air holes 24 may be covered with a waterproof, breathable material 25, such as felt. The waterproof and breathable material 25 allows air to freely permeate through the air holes 24, and prevents outside water, contaminants, etc. from penetrating through the air holes 24 and entering the bearing chamber 600. The waterproof and breathable material 25 may be provided with a plurality of layers, for example, the waterproof and breathable material 25 may be provided with two layers, and the two layers of waterproof and breathable material 25 are respectively covered on the surfaces of the sealing portions on both sides of the air hole 24. It will be appreciated that a waterproof and breathable material may also be inserted into the air holes 24.

The axially inner side of the slinger 3, i.e., the surface of the slinger 3 facing the first seal lip 21, and particularly the portion of the slinger 3 contacting the first seal lip 21, may be a frosted surface which may be formed by a sand blasting process, the frosted surface having a relatively high surface roughness, for example, a roughness of the frosted surface of between Ra0.6 μm and Ra 1.6 μm.

Because of the rough surface, the contact area of the first sealing lip 21 with the frosted surface has a small clearance to allow air to pass freely in both directions and also to prevent the passage of environmental contaminants such as muddy water. This prevents the waterproof breathable material 25 from being clogged with contaminants and losing or detracting from the breathable properties.

Referring to fig. 5, the right side of the cartridge type sealing device 500 is the side where the bearing chamber 600 is located, and the left side of the cartridge type sealing device 500 is the external environment. When the bearing rotates at a high speed for a certain time or the bearing encounters a high temperature transmitted from the brake system, air in the bearing chamber 600 expands, resulting in an increase in air pressure. As shown by the arrow direction in fig. 5, air in the bearing chamber 600 can enter the chamber C through the air hole 24 and be discharged to the outside through the gap between the first seal lip 21 and the flinger radial part 32. When the bearing temperature is reduced, the pressure in the bearing cavity 600 is reduced, and air outside the bearing cavity 600 can freely pass through the gap between the first sealing lip 21 and the sandblasted surface, enter the cavity C, and then enter the bearing cavity 600 from the air hole 24, so that the balance between the bearing cavity 600 and the external environment air pressure is maintained, the bearing cavity 600 is prevented from forming a vacuum state, and the sealing performance and the service life of the box-type sealing device 500 can be improved.

The waterproof and breathable material 25, such as felt, may be glued to, or vulcanized onto, the rubber material of the sealing portion 2 during the rubber vulcanization process. However, the sealing portion 2 is not limited to being made of a rubber material, but may be made of other elastic materials, or include other elastic materials. For example, at least one sealing lip of the sealing part 2 may be composed of polytetrafluoroethylene or comprise a polytetrafluoroethylene layer.

It is to be understood that the present application is not limited to the above-described embodiments.

For example, in an alternative, an air hole (an example of a first air hole) that communicates the inside and the outside of the cartridge type sealing device may be formed in the skeleton radial portion 12 radially outside the base portion of the first seal lip 21. A waterproof and breathable material such as felt may be inserted into the air holes and/or provided on one or both sides of the air holes. At this time, the gap between the first seal lip 21 and the sandblasted surface described above is not necessary.

In another alternative, an air hole (an example of a second air hole) and a waterproof and breathable material similar to the air hole 24 may be provided in the first seal lip 21 or the flinger radial portion 32 (a portion located radially inside the first seal lip 21).

In the oil seal 400 shown in fig. 2, air holes (an example of the first air holes) and a waterproof and breathable material similar to the air holes 24 may be provided in the seal portion (for example, in a rubber material) or in the skeleton.

The cartridge seal 500 described above may also be used in other devices having a first member and a second member that rotate relative to each other, for example, it may be used at the output of an electric drive.

It will be appreciated that aspects of the above embodiments or examples may be suitably substituted or combined. The gist of the present application is to provide a gas passage that allows ventilation between the inside (the sealed chamber side) and the outside (the environment side) of the sealing device, but prevents the passage of contaminants such as water and particles.

While the present application has been described in detail using the above embodiments, it will be apparent to those skilled in the art that the present application is not limited to the embodiments described in the present specification. The present application can be modified and implemented as a modified embodiment without departing from the spirit and scope of the present application as defined by the claims. Accordingly, the descriptions in this specification are for purposes of illustration and are not intended to be limiting in any way.

Claims

1. A sealing device for sealing a space between a first member and a second member capable of relative rotation,

the sealing device is characterized by comprising a framework (1) and a sealing part (2), wherein a gas channel for ventilating the inner side and the outer side of the sealing device but preventing pollutants from passing through is arranged in the framework (1) or the sealing part (2).

2. The sealing device of claim 1, wherein the gas passage comprises:

a first air hole provided in the frame (1) or the sealing portion (2); and

3. The sealing device according to claim 2, further comprising a slinger (3), the sealing portion (2) comprising a first sealing lip (21) as a dust lip, the first sealing lip (21) extending from the backbone (1) toward the slinger (3), a face of the slinger (3) in contact with the first sealing lip (21) comprising a frosted surface, the gas channel further comprising a gap between a free end of the first sealing lip (21) and the frosted surface.

4. A sealing device according to claim 3, wherein the frosted surface has a roughness between Ra0.6 μm and Ra 1.6 μm.

5. A sealing device according to claim 3, wherein,

the seal part (2) further includes a second seal lip (22) as a main lip, the second seal lip (22) extending from the skeleton (1) toward the slinger (3) or the first member supporting the slinger (3), a free end of the second seal lip (22) being in contact with the slinger (3) or the first member,

the first sealing lip (21), the second sealing lip (22) and the flinger (3), or the first sealing lip (21), the second sealing lip (22), the flinger (3) and the first component enclose an annular chamber (C),

the chamber (C) communicates with the axially inner side of the sealing device via the first air hole, and the chamber (C) communicates with the axially outer side of the sealing device via a gap between the first sealing lip (21) and the frosted surface.

6. The sealing device according to claim 5, characterized in that the first air hole is located between the base end of the first sealing lip (21) and the base end of the second sealing lip (22), the first air hole passing through the sealing portion (2) without passing through the skeleton (1).

7. A sealing device according to claim 3, wherein the gas passage comprises:

a second air hole provided in the slinger (3) or the first seal lip (21); and

8. The sealing device according to claim 2 or 7, wherein a plurality of the first air holes are provided along a circumferential direction of the sealing device; and/or

9. The sealing device of claim 2 or 7, wherein the waterproof, breathable material is felt.

10. A bearing, characterized in that it comprises a sealing device according to any one of claims 1 to 9.