Sealing device

Abstract

The present invention provides a sealing device for sealing a radial gap between a first component and a second component which are sleeved on each other. The sealing device comprises an inner sealing component (20), a dust cover (10) and a sweeping lip (40) which are all annular. The inner sealing component (20) is assembled with the second component in a radial interference fit, the dust cover (10) is assembled with the first component in a radial interference fit, a skeleton (21) of the inner sealing component (20) and the dust cover (10) have a radial gap, the sweeping lip (40) is fixed to the dust cover (10), and the sweeping lip comprises a hollow portion (41) which can at least allow a fluid to pass axially, the hollow portion extends radially toward the second component and is close to the end face of the skeleton (21) located on the axial outer side and / or the end face of the second component located on the axial outer side. The sealing device according to the present invention can improve the sealing effect without excessively increasing the friction between the components of the sealing device or between the sealing device and, for example, a bearing.

Description

Technical Field

[0001] The present invention relates to the field of sealing, in particular to a sealing device for a bearing, and particularly to a sealing device for a hub bearing. Background Art

[0002] Figure 1 A known cassette seal device for a hub bearing (also referred to as a bearing seal device, or simply a seal device) is shown, which includes a dust cover 10 and an inner seal assembly 20. The dust cover 10 is fixed to the inner ring 31 of the bearing in an interference fit manner. The inner seal assembly 20 is installed on the axial inner side of the dust cover 10, and the inner seal assembly 20 includes a skeleton 21 and a sealing component 22 fixed to the skeleton 21, and the skeleton 21 is fixed to the outer ring 32 of the bearing in an interference fit manner. The main lip 221, the dust lip 222 and the centrifugal lip 223 of the sealing component 22 all extend toward the dust cover 10 and contact the dust cover 10 with a deformation amount. It should be understood that the sealing component 22 and the dust cover 10 shown in the figure have overlapping parts, which does not mean that the sealing component 22 enters the inside of the dust cover 10, but only means that the sealing component 22 contacts / abuts with the dust cover 10 in an interference fit.

[0003] When the inner ring 31 of the bearing rotates relative to the outer ring 32, the dust cover 10 and the inner seal assembly 20 of the sealing device can rotate relative to each other. Since the main lip 221, the dust lip 222 and the centrifugal lip 223 are in contact with the dust cover 10 with deformation, three sealing barriers are formed, so that the sealing device can prevent pollutants (such as sewage) in the external environment from entering the interior of the bearing.

[0004] However, in the case where the bearing may be in a harsh environment for a long time (for example, the wheel hub bearing may often come into contact with sewage), the sealing effect of the above sealing device needs to be further improved. Summary of the invention

[0005] The purpose of the present invention is to overcome or at least alleviate the deficiencies of the above-mentioned prior art and to provide a sealing device with better sealing effect.

[0006] The present invention provides a sealing device, which is used to seal the radial gap between a first component and a second component which are sleeved on each other, so as to prevent foreign matter from entering the axial inner side of the sealing device from the axial outer side of the sealing device.

[0007] The sealing device comprises an inner sealing component, a dust cover and a sweeping lip, all of which are annular. The inner sealing component is assembled with the second component in a radial interference fit, the dust cover is assembled with the first component in a radial interference fit, and a gap is provided between the skeleton of the inner sealing component and the dust cover in a radial direction.

[0008] The sweeping lip is fixed to the dust cover, and the sweeping lip includes a hollow portion that allows at least fluid to pass axially, the hollow portion extends radially toward the second component and is close to the end surface of the skeleton located on the axial outside and / or the end surface of the second component located on the axial outside.

[0009] In at least one embodiment, the hollow portion is composed of a plurality of strip-shaped fingers arranged along a circumferential direction, and there is a gap between adjacent fingers.

[0010] In at least one embodiment, each of the fingers extends in a radial direction.

[0011] In at least one embodiment, the sweeping lip is fixed to a first end surface of the dust cover located on the axial outer side.

[0012] The first end surface is axially flush with the end surface of the second component located on the axial outer side, the hollow portion is in contact with the end surface of the second component located on the axial outer side, and / or

[0013] The first end surface is flush with the end surface of the skeleton located on the axial outer side in the axial direction, and the hollow portion is in contact with the end surface of the skeleton located on the axial outer side.

[0014] In at least one embodiment, the sweeping lip is made of felt, and the sweeping lip is fixed to the dust cover by bonding, or

[0015] The sweeping lip is made of rubber, and is fixed to the dust cover by a vulcanization process.

[0016] In at least one embodiment, the first component is an inner ring of a bearing, and the second component is an outer ring of the bearing. When the bearing is in operation, the inner ring rotates circumferentially.

[0017] In at least one embodiment, the sweeping lip further includes an annular connecting portion, the connecting portion is fixed to the dust cover, and the hollow portion is connected to the outer periphery of the connecting portion.

[0018] In at least one embodiment, the bearing is a wheel hub bearing.

[0019] In at least one embodiment, the first component is an outer ring of a bearing, and the second component is an inner ring of a bearing. When the bearing is in operation, the outer ring rotates circumferentially.

[0020] In at least one embodiment, the sweeping lip further includes an annular connecting portion, the connecting portion is fixed to the dust cover, and the hollow portion is connected to an inner circumference of the connecting portion.

[0021] According to the sealing device of the present invention, the sealing effect can be improved without excessively increasing the friction between the components of the sealing device or between the sealing device and, for example, a bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a known cassette seal device for a wheel hub bearing is shown in an axial section.

[0023] Figure 2 A schematic diagram of an axially sectioned sealing device according to the present invention is shown.

[0024] Description of Reference Numerals

[0025] 10 dust cover; 11 cover axial portion; 12 cover radial portion; 121 first end surface;

[0026] 20 inner sealing assembly; 21 frame; 211 frame axial portion; 212 frame radial portion; 22 sealing component; 221 main lip; 222 dust lip; 223 centrifugal lip;

[0027] 31 inner ring; 32 outer ring;

[0028] 40 sweeping lip; 41 hollow portion; 411 finger; 42 connecting portion;

[0029] A is axial; R is radial; W is axially outward. DETAILED DESCRIPTION

[0030] The exemplary embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present invention, and are not intended to exhaust all possible modes of the present invention, nor to limit the scope of the present invention.

[0031] (First Embodiment)

[0032] Reference Figure 2 The specific structure of the sealing device according to the first embodiment of the present invention is introduced. In the figure, A represents the axial direction of the sealing device, and the axial direction A is consistent with the axial direction of the bearing; R represents the radial direction of the sealing device, and the radial direction R is consistent with the radial direction of the bearing; the arrow W points to the axial outside, and the direction opposite to the arrow W is the axial inside. The axial outside here refers to the outer side (environmental side) of the bearing, and the axial inside refers to the inner side of the bearing. In addition, the circumferential direction referred to in the present invention is consistent with the circumferential direction of the bearing.

[0033] The sealing device comprises a dust cover 10, an inner seal assembly 20 and a sweeping lip 40. When the bearing is working, its outer ring 32 (also called the second component) is stationary and the inner ring 31 (also called the first component) is rotating.

[0034] The inner sealing assembly 20 includes a frame 21 and a sealing component 22 fixed to the frame 21 .

[0035] The skeleton 21 is annular and includes an axial portion 211 extending along the axial direction A and a radial portion 212 extending along the radial direction R, so that the cross section of the skeleton 21 along the axial direction A is two symmetrical L-shaped ( Figure 2 Half of a cross section of the skeleton 21 along the axial direction A is shown).

[0036] The skeleton axial portion 211 and the outer ring 32 are assembled together in an interference fit connection manner in the radial direction R.

[0037] The sealing component 22 is fixed to the frame 21, and the sealing component 22 includes a main lip 221, a dust lip 222, and a centrifugal lip 223. The main lip 221, the dust lip 222, and the centrifugal lip 223 all extend toward the dust cover 10 and contact the dust cover 10 with a deformation amount. In the direction pointing to the axial outer side, the positional relationship of the above three lips is the dust lip 222, the main lip 221, and the centrifugal lip 223. The main lip 221 and the dust lip 222 both extend radially inward and axially outward at the same time and contact the cover axial portion 11 to be described below, and the centrifugal lip 223 extends radially outward and axially outward at the same time and contacts the cover radial portion 12 to be described below.

[0038] The dust cover 10 is annular and includes a cover axial portion 11 extending along the axial direction A and a cover radial portion 12 extending along the radial direction R, so that the cross section of the dust cover 10 along the axial direction A is two symmetrical substantially L-shaped ( Figure 2 A half of a cross section of the dust cover 10 along the axial direction A is shown).

[0039] The cover axial portion 11 and the inner ring 31 of the bearing are assembled together in an interference fit connection in the radial direction R, and the first end face 121 of the cover radial portion 12 located on the axial outer side W is substantially flush with the end face of the outer ring 32 located on the axial outer side W in the axial direction. The cover radial portion 12 is located axially outside the framework radial portion 212. The cover radial portion 12 does not contact the framework axial portion 211, and a gap is left between the two in the radial direction.

[0040] It should be understood that the "radial gap between the skeleton 21 of the inner seal assembly 20 and the dust cover 10" mentioned in the present invention means that a radial gap is left between the axially outer portions of the skeleton 21 of the inner seal assembly 20 and the dust cover 10. More specifically, it refers to the "radial gap between the radial portion 12 of the cover and the axial portion 211 of the skeleton".

[0041] The sweeping lip 40 is annular and fixed to the dust cover 10. The sweeping lip 40 is made of a flexible material (such as rubber or felt). When the sweeping lip 40 is made of rubber, it can be fixed to the dust cover 10 by, for example, a vulcanization process; when the sweeping lip 40 is made of felt, it can be fixed to the dust cover 10 by, for example, gluing.

[0042] The sweeping lip 40 includes a connecting portion 42 located radially inwardly and a hollow portion 41 located radially outwardly.

[0043] The connecting portion 42 may be a complete ring that is continuous in the circumferential direction, and the connecting portion 42 is fixed to the first end surface 121. The outer circumference of the connecting portion 42 protrudes radially outward to form a plurality of fingers 411, each of which is in the shape of an elongated strip and extends radially along the sweeping lip 40, and adjacent fingers 411 are spaced apart. The plurality of fingers 411 arranged circumferentially form an annular hollow portion 41 that is hollowed out in the axial direction A and at least allows fluid to pass through.

[0044] Each finger 411 extends radially outward beyond the axial portion 211 of the skeleton and abuts against the end face of the outer ring 32 located on the axial outer side W. In other words, the outer peripheral portion of the hollow portion 41 abuts against the end face of the outer ring 32 located on the axial outer side W.

[0045] Preferably, the finger 411 also abuts against the end surface of the skeleton axial portion 211 located on the axial outer side W, that is, the first end surface 121 of the cover radial portion 12 located on the axial outer side W, the end surface of the skeleton axial portion 211 located on the axial outer side W, and the end surface of the outer ring 32 located on the axial outer side W are axially flush. In other embodiments, the finger 411 may also extend only to the radial region where the skeleton axial portion 211 is located without contacting the outer ring 32.

[0046] It should be understood that there may be a gap between the finger 411 and the framework axial portion 211 and / or the outer ring 32 in the axial direction A, which can still prevent or reduce foreign matter from entering the sealing device and the axial inner side of the sealing device from the axial outer side of the sealing device. Therefore, those skilled in the art can understand that the finger 411 and the framework axial portion 211 and / or the outer ring 32 only need to be close to each other in the axial direction A. Those skilled in the art can also understand that the closeness here includes abutting and having a small gap.

[0047] Next, it will be described how the sealing device with the sweeping lip 40 can improve the sealing effect.

[0048] When the bearing is in a non-operating state, the inner ring 31, the outer ring 32, the inner seal assembly 20, the dust cover 10 and the sweeping lip 40 all remain stationary in the circumferential direction. At this time, the radial multiple fingers 411 serve as the first barrier located on the axial outer side of the sealing device to prevent large-sized foreign matter (such as particles with a diameter greater than the spacing width between adjacent fingers 411) from entering the sealing device.

[0049] When the bearing is in operation, the inner ring 31 of the bearing rotates relative to the outer ring 32, the motion state of the inner seal assembly 20 is the same as that of the outer ring 32, the motion state of the dust cover 10 and the sweeping lip 40 is the same as that of the inner ring 31, and the sweeping lip 40 rotates relative to the outer ring 32 (hereinafter referred to as the sweeping lip 40 rotation). Since the hollow portion 41 of the sweeping lip 40 covers the gap between the dust cover 10 and the outer ring 32 (or the skeleton 21) in the radial direction, when the sweeping lip 40 rotates, the gap is dynamically and frequently covered by the finger 411. Foreign matter (such as sewage or solid particles) that intends to enter the sealing device from the axial outside through the above gap at random times will most likely hit the finger 411 and be blocked.

[0050] In addition, foreign matter (especially liquid, such as sewage) accidentally entering the interior of the sealing device can also flow out of the sealing device from the spaces between adjacent fingers 411 .

[0051] Since there is a gap between adjacent fingers 411, the contact area between the entire hollow portion 41 and the outer ring 32 is small; and the fingers 411 are soft, when the fingers 411 contact the outer ring 32, the fingers 411 can be slightly deformed in the axial direction, so that the axial force between the fingers 411 and the outer ring 32 is small, so when the bearing is in working state, the friction between the hollow portion 41 and the outer ring 32 is small.

[0052] (Second Embodiment)

[0053] This embodiment is a variation of the first embodiment. In this embodiment, the working state of the bearing is that the inner ring (also called the second component) is stationary and the outer ring (also called the first component) is rotating.

[0054] Since it is desired that the sweeping lip can rotate circumferentially relative to foreign objects that may enter the gap between the dust cover and the frame to increase the probability of foreign objects hitting the sweeping lip, in contrast to the first embodiment, in this embodiment, the dust cover that fixes the sweeping lip is assembled to the outer ring of the bearing with an interference fit, and the inner seal assembly is assembled to the inner ring of the bearing with an interference fit.

[0055] The hollow portion (or finger) of the sweeping lip is located on the inner circumference of the connecting portion, and each finger extends radially inward to the end face of the finger abutting against the axially outer side of the axial portion of the skeleton, or even to the end face of the finger abutting against the axially outer side of the inner ring.

[0056] When the bearing is working, the sweeping lip rotates with the dust cover and the outer ring of the bearing, dynamically shielding the radial gap between the dust cover and the frame.

[0057] The present invention has at least one of the following advantages:

[0058] (i) The sweeping lip 40 added in the present invention can statically block large-sized foreign matter from entering the sealing device when the bearing is in a non-working state, and can dynamically prevent smaller-sized or even liquid foreign matter from entering the sealing device by circumferential sweeping when the bearing is in a working state; and the hollow portion 41 of the sweeping lip 40 allows foreign matter that enters the sealing device in an unexpected state to leave the sealing device through the gaps between adjacent fingers 411, thereby preventing these foreign matter from further entering the interior of the bearing.

[0059] (ii) The hollow portion 41 is made of a soft material and has a small contact area with the outer ring 32, so that after adding the sweeping lip 40, the sealing device does not add excessive friction (or torque) to the operation of the bearing.

[0060] (iii) The sweeping lip 40 has a simple structure and is easy to manufacture. The sweeping lip 40 and the dust cover 10 are simply fixed to each other, and the addition of the sweeping lip 40 does not require changes to the original design of other components of the sealing device.

[0061] Of course, the present invention is not limited to the above-mentioned embodiments, and those skilled in the art can make various modifications to the above-mentioned embodiments of the present invention under the guidance of the present invention without departing from the scope of the present invention. For example:

[0062] (i) Although Figure 2 In the illustrated embodiment, a plurality of spaced-apart fingers 411 extend radially to form a hollow portion 41, but the present invention is not limited thereto. For example, the fingers 411 may extend at a certain angle to the radial direction, or the fingers 411 may be arc-shaped, or the solid portion of the hollow portion 41 may form other patterns.

[0063] (ii) The sealing device according to the present invention is not limited to being used for wheel hub bearings, or even for bearings. For example, the sealing device according to the present invention can also be used to seal the radial gap between two other components (first component and second component) that rotate relative to each other and are nested with each other.

Claims

1. A sealing device, which is used to seal the radial gap between a first component and a second component which are sleeved on each other, so as to prevent foreign matter from entering the axial inner side of the sealing device from the axial outer side (W) of the sealing device, The sealing device comprises an inner sealing component (20), a dust cover (10) and a sweeping lip (40) all of which are annular; the inner sealing component (20) and the second component are assembled in a radial interference fit; the dust cover (10) and the first component are assembled in a radial interference fit; a radial gap is provided between a skeleton (21) of the inner sealing component (20) and the dust cover (10); The sweeping lip (40) is fixed to the dust cover (10), and the sweeping lip (40) includes a connecting portion (42) and a hollow portion (41), wherein the connecting portion (42) is a complete ring that is continuous in the circumferential direction, and the connecting portion (42) is fixed to a first end surface (121) of the dust cover (10) that is located on the axial outer side (W), the connecting portion (42) is located on the radial inner side, and the hollow portion (41) is located on the radial outer side, and the outer circumference of the connecting portion (42) protrudes toward the radial outer side to form a plurality of fingers (411), or The connecting portion (42) is located on the radially outer side, and the hollow portion (41) is located on the radially inner side. The inner circumference of the connecting portion (42) protrudes radially inward to form a plurality of fingers (411). The plurality of fingers (411) arranged circumferentially form the hollow portion (41) that allows at least axial passage of fluid. The hollow portion (41) extends radially toward the second component and is close to the end face of the skeleton (21) located on the axially outer side (W) and / or the end face of the second component located on the axially outer side (W).

2. The sealing device according to claim 1, characterized in that: The first end surface (121) is axially flush with the end surface of the second component located on the axial outer side (W), the hollow portion (41) is in contact with the end surface of the second component located on the axial outer side (W), and / or The first end surface (121) is axially flush with the end surface of the skeleton (21) located on the axial outer side (W), and the hollow portion (41) is in contact with the end surface of the skeleton (21) located on the axial outer side (W).

3. The sealing device according to claim 1, characterized in that: The sweeping lip (40) is made of felt, and the sweeping lip (40) is fixed to the dust cover (10) by bonding, or The sweeping lip (40) is made of rubber and is fixed to the dust cover (10) by a vulcanization process.

4. The sealing device according to any one of claims 1 to 3, characterized in that: When the connecting portion (42) is located radially inward, the hollow portion (41) is located radially outward, and the outer periphery of the connecting portion (42) protrudes radially outward to form a plurality of fingers (411), the first component is the inner ring (31) of the bearing, and the second component is the outer ring (32) of the bearing. When the bearing is working, the inner ring (31) rotates circumferentially.

5. The sealing device according to claim 4, characterized in that: The bearing is a wheel hub bearing.

6. The sealing device according to any one of claims 1 to 3, characterized in that: When the connecting portion (42) is located on the radially outer side, the hollow portion (41) is located on the radially inner side, and the inner circumference of the connecting portion (42) protrudes radially inward to form a plurality of fingers (411), the first component is the outer ring of the bearing, and the second component is the inner ring of the bearing. When the bearing is working, the outer ring rotates circumferentially.

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