JP2021131100A - Sealing device and sealing structure - Google Patents

Abstract

To provide a sealing device which is high in water discharge performance and also high in protection performance from water to a sealing object.SOLUTION: A sealing device 21 seals a gap between an inside member 6 and an outside member 8 which relatively rotate with respect to each other. The sealing device has a first seal member 30 attached to the outside member, and a second seal member 50 attached to the inside member. An annular space 60 is formed between an annular part 34 of the first seal member and a flange 52B of the second seal member. An annular first gap 61 is formed between a cylinder part 33 of the first seal member and an external end edge 51B of the flange of the second seal member. An annular second gap 62 is formed between a salient part 35 of the first seal member and the flange of the second seal member. The second gap connects the first gap and the space, and at least a part of the second gap is orthogonal to the first gap. A width of the second gap is equal to or narrower than 0.85 mm, and a length of the second gap is equal to or longer than 2 mm.SELECTED DRAWING: Figure 2

Description

The present invention relates to a sealing device and a sealing structure.

Rolling bearings, such as ball bearings, are well known and are used, for example, in automobile hubs. As a sealing device for sealing the inside of a rolling bearing, there is one described in Patent Document 1. This sealing device is a combination of a member fixed to the outer member of the rolling bearing and a member fixed to the inner member of the rolling bearing. The sealing device has a function of sealing the lubricant (grease) inside the bearing and a function of sealing so that foreign matter such as water or dust does not enter the inside of the bearing from the outside.

Japanese Unexamined Patent Publication No. 2012-22973

For this type of sealing device, when used in an environment with a lot of water (including muddy water or salt water), it is required to enhance the function of protecting water from entering the inside of the sealed object (for example, bearing). Will be done. Further, even if water enters the sealing device, it is desirable that the water can be discharged promptly.

Therefore, the present invention provides a sealing device and a sealing structure having high water discharge performance and high protection performance from water to a sealed object.

The sealing device according to an aspect of the present invention is arranged between a relatively rotating inner member and an outer member, and seals a gap between the inner member and the outer member. The sealing device is attached to the outer member and has a cylindrical portion, an annular portion, and a protruding portion, and the annular portion is arranged radially inside the cylindrical portion and spreads radially inward toward the inner member. A first sealing member, which is connected to the cylindrical portion and the annular portion, projects radially inward from the cylindrical portion, and projects from the annular portion, and is attached to the inner member and has a flange. The flange extends outward in the radial direction, and includes a second sealing member facing the annular portion of the first sealing member. An annular space is provided between the annular portion of the first sealing member and the flange of the second sealing member. An annular first gap is provided between the cylindrical portion of the first sealing member and the outer edge of the flange of the second sealing member. An annular second gap is provided between the protruding portion of the first sealing member and the flange of the second sealing member. The second gap connects the first gap and the space, and at least a part of the second gap is orthogonal to the first gap. The width of the second gap is 0.85 mm or less, and the length of the second gap is 2 mm or more.

In this aspect, with the relative rotation of the inner and outer members, the water in the space between the annular portion of the first sealing member and the flange of the second sealing member is the second gap and the first. It is quickly discharged to the outside through the gap. Further, since the width of the second gap is small and the length of the second gap is large, water enters the space between the annular portion of the first sealing member and the flange of the second sealing member from the outside. Is suppressed.

The sealing structure according to an aspect of the present invention includes an inner member having a cylindrical portion, a flange extending radially outward of the cylindrical portion, an outer member that rotates relative to the inner member, and the outer member. It has a cylindrical portion, an annular portion, and a protruding portion, and the annular portion is arranged radially inside the cylindrical portion and spreads radially inward toward the cylindrical portion of the inner member, and the projecting portion. The portion is connected to the cylindrical portion and the annular portion, and includes a sealing member that projects radially inward from the cylindrical portion and protrudes from the annular portion. An annular space is provided between the annular portion of the seal member and the flange of the inner member. An annular first gap is provided between the cylindrical portion of the sealing member and the outer edge of the flange of the inner member. An annular second gap is provided between the protruding portion of the sealing member and the flange of the inner member. The second gap connects the first gap and the space, and at least a part of the second gap is orthogonal to the first gap. The width of the second gap is 0.85 mm or less, and the length of the second gap is 2 mm or more.

In this embodiment, as the inner member and the outer member rotate relative to each other, the water in the space between the annular portion of the sealing member and the flange of the inner member promptly goes out through the second gap and the first gap. It is discharged. Further, since the width of the second gap is small and the length of the second gap is large, the intrusion of water from the outside into the space between the annular portion of the seal member and the flange of the inner member is suppressed.

It is a partial cross-sectional view of an example of a rolling bearing in which the sealing device according to each embodiment of the present invention is used. It is a partial cross-sectional view of the sealing device which concerns on 1st Embodiment of this invention. It is schematic cross-sectional view which shows the apparatus used for the test for confirming the invasion suppression effect of water with respect to the sealing apparatus which concerns on 1st Embodiment. It is a graph which shows the result of the said test. It is a partial cross-sectional view of the sealing device which concerns on the modification of 1st Embodiment of this invention. It is a partial cross-sectional view of the sealing device which concerns on other modification of 1st Embodiment of this invention. It is a partial cross-sectional view of the sealed structure which concerns on 2nd Embodiment of this invention. It is a partial cross-sectional view of the sealed structure which concerns on the modification of 2nd Embodiment of this invention.

Hereinafter, various embodiments according to the present invention will be described with reference to the accompanying drawings. Drawing scales are not always accurate and some features may be exaggerated or omitted.

FIG. 1 shows a hub bearing for an automobile, which is an example of a rolling bearing in which the sealing device according to the embodiment of the present invention is used. However, the application of the present invention is not limited to hub bearings, and the present invention can be applied to other rolling bearings. Further, in the following description, the hub bearing is a ball bearing, but the application of the present invention is not limited to the ball bearing, and other rolling bearings such as roller bearings and needle bearings having other types of rolling elements. The present invention is also applicable. The present invention is also applicable to rolling bearings used in machines other than automobiles.

The hub bearing 1 is arranged outside the hub (inner member) 4 having a hole 2 into which the spindle (not shown) is inserted, the inner ring (inner member) 6 attached to the hub 4, and the outside thereof. The outer ring (outer member) 8, the plurality of balls 10 arranged in a row between the hub 4 and the outer ring 8, and the plurality of balls 12 arranged in a row between the inner ring 6 and the outer ring 8, and these. It has a plurality of cages 14 and 15 for holding the ball in place.

While the outer ring 8 is fixed, the hub 4 and the inner ring 6 rotate as the spindle rotates.

The common central axis Ax of the spindle and the hub bearing 1 extends in the vertical direction of FIG. In FIG. 1, only the left side portion with respect to the central axis Ax is shown. Although not shown in detail, the upper side of FIG. 1 is the outside (outboard side) where the wheels of the automobile are arranged, and the lower side is the inside (inboard side) where the differential gears and the like are arranged. The outside and the inside shown in FIG. 1 mean the outside and the inside in the radial direction, respectively.

The outer ring 8 of the hub bearing 1 is fixed to the hub knuckle 16. The hub 4 has an outboard side flange 18 projecting radially outward from the outer ring 8. Wheels can be attached to the outboard side flange 18 by means of hub bolts 19.

A sealing device 20 for sealing the gap between the outer ring 8 and the hub 4 is arranged near the end of the outer ring 8 on the outboard side, and inside the end of the outer ring 8 on the inboard side. , A sealing device 21 that seals the gap between the outer ring 8 and the inner ring 6 is arranged. By the action of these sealing devices 20 and 21, the outflow of grease, that is, the lubricant from the inside of the hub bearing 1 is prevented, and foreign matter (water (including muddy water or salt water)) from the outside to the inside of the hub bearing 1 is prevented. And the inflow of dust) is prevented. In FIG. 1, the arrow F shows an example of the direction of the flow of foreign matter from the outside.

The sealing device 20 is arranged between the rotating hub 4 of the hub bearing 1 and the cylindrical end 8A of the fixed outer ring 8 on the outboard side, and seals the gap between the hub 4 and the outer ring 8. do. The sealing device 21 is arranged between the rotating inner ring 6 of the hub bearing 1 and the end portion 8B of the fixed outer ring 8 on the inboard side, and seals the gap between the inner ring 6 and the outer ring 8.

1st Embodiment As shown in FIG. 2, the sealing device 21 is arranged in a gap between an end portion 8B of the outer ring 8 of the hub bearing 1 on the inboard side and an inner ring 6 of the hub bearing 1. Although the sealing device 21 is annular, only the left side portion thereof is shown in FIG.

The sealing device 21 has a composite structure including a first sealing member 30 and a second sealing member 50.

The first seal member 30 is a fixed seal member that is attached to the outer ring 8 and does not rotate. The first sealing member 30 has a composite structure having an elastic ring 31 and a rigid ring 32. The elastic ring 31 is made of an elastic material, for example, an elastomer. The rigid ring 32 is made of a rigid material, for example metal, to reinforce the elastic ring 31. The rigid ring 32 has a substantially L-shaped cross section. A part of the rigid ring 32 is embedded in the elastic ring 31 and is in close contact with the elastic ring 31.

The first sealing member 30 has a cylindrical portion 33, an annular portion 34, a protruding portion 35, and lips 36, 37, 38.

The cylindrical portion 33 constitutes a mounting portion to be attached to the outer ring 8. Specifically, the cylindrical portion 33 is fitted (that is, press-fitted) into the end portion 8B of the outer ring 8 by a tightening method.

The annular portion 34 is an annular shape, is arranged radially inward of the cylindrical portion 33, and extends radially inward from the cylindrical portion 33 toward the inner ring 6. The cylindrical portion 33 and the annular portion 34 are composed of a rigid ring 32 and an elastic ring 31.

The projecting portion 35 is connected to the cylindrical portion 33 and the annular portion 34, projects radially inward from the cylindrical portion 33, and projects from the annular portion 34 toward the inboard side. The protruding portion 35 is composed of an elastic ring 31. In this embodiment, the protrusion 35 is an annulus having a rectangular cross section.

The lips 36, 37, 38 extend from the inner end of the annular portion 34 toward the second sealing member 50. The lips 36, 37, 38 are composed of an elastic ring 31.

The second seal member 50 can also be referred to as a slinger, that is, a rotary seal member. The second seal member 50 is attached to the inner ring 6, and when the inner ring 6 rotates, the second seal member 50 rotates together with the inner ring 6 to repel foreign matter arriving from the outside.

In this embodiment, the second sealing member 50 also has a composite structure having an elastic ring 51 and a rigid ring 52. The rigid ring 52 is made of a rigid material, for example metal.

The rigid ring 52 has a substantially L-shaped cross section. Specifically, the elastic ring 51 includes a cylindrical sleeve 52A and an annular flange 52B extending radially outward from the sleeve 52A. The sleeve 52A constitutes a mounting portion to be mounted on the inner ring 6. Specifically, the end portion of the inner ring 6 is fitted (that is, press-fitted) into the sleeve 52A by a tightening method.

The flange 52B is arranged radially outward of the sleeve 52A, extends radially outward, and faces the annular portion 34 of the first seal member 30. In this embodiment, the flange 52B is a flat plate and is in a plane perpendicular to the axis of the sleeve 52A. In this embodiment, the flange 52B of the second seal member 50 is parallel to the annular portion 34 of the first seal member 30.

The elastic ring 51 is in close contact with the flange 52B of the rigid ring 52. In this embodiment, the elastic ring 51 is provided to measure the rotational speed of the inner ring 6. Specifically, the elastic ring 51 is formed of an elastomer material containing magnetic metal powder and ceramic powder, and has a large number of S poles and N poles depending on the magnetic metal powder. In the thick plate portion 51A of the elastic ring 51, a large number of S poles and N poles are alternately arranged at equiangular intervals in the circumferential direction. The rotation angle of the elastic ring 51 can be measured by a magnetic rotary encoder (not shown). Since the material of the elastic ring 51 contains metal powder, it has a higher hardness than a normal elastomer material and is not easily damaged by foreign matter.

The elastic ring 51 has a thick plate portion 51A, an outer peripheral edge portion 51B, and a thin plate portion 51C. The thick plate portion 51A is joined to the inboard side surface of the flange 52B of the rigid ring 52. The outer peripheral edge 51B is joined to the outer edge of the flange 52B. The thin plate portion 51C is joined to the outboard side surface of the flange 52B.

The elastic ring 51 and the flange 52B are joined to each other and can be regarded as forming one flange 53. That is, the thick plate portion 51A, the outer peripheral edge portion 51B, and the thin plate portion 51C can be regarded as the portions of the flange 53. In particular, the outer peripheral edge portion 51B can be regarded as the outer edge of the flange 53.

The flange 53 faces the annular portion 34 of the first sealing member 30, and an annular space 60 is provided between the annular portion 34 and the flange 53.

The lip 36 of the first sealing member 30 is a radial lip (grease lip) extending radially inward from the inner end of the annular portion 34. The lip 36 extends toward the sleeve 52A of the second sealing member 50, and the tip of the lip 36 comes into contact with the sleeve 52A. The lip 36 extends radially inward and toward the outboard side, and mainly serves to prevent the outflow of the lubricant from the inside of the hub bearing 1.

The lip 37 is a radial lip (dust strip) extending radially inward from the inner end of the annular portion 34. The lip 37 extends toward the sleeve 52A of the second sealing member 50, and the tip of the lip 37 contacts the sleeve 52A. The lip 36 extends inward in the radial direction and toward the inboard side, and mainly serves to prevent the inflow of foreign matter from the outside into the inside of the hub bearing 1.

The lip 38 is an axial lip (side lip) extending laterally from the annular portion 34. The tip of the lip 38 extends radially outward and toward the inboard side and comes into contact with the flange 52B of the rigid ring 52 of the second sealing member 50. The lip 38 mainly plays a role of preventing the inflow of foreign matter from the outside into the inside of the hub bearing 1.

Since the inner ring 6 and the second seal member 50 rotate while the first seal member 30 is attached to the fixed outer ring 8, each of the lips 36, 37, 38 is attached to the second seal member 50. It slides against it.

However, the lips 37 and 38 are not absolutely indispensable and can be omitted. When the lips 37 and 38 are omitted, the torque applied by the first sealing member 30 to the second sealing member 50 is reduced. When the lip 37 is provided, the lip 37 does not have to come into contact with the sleeve 52A in order to reduce torque. When the lip 38 is provided, the lip 38 does not have to come into contact with the flange 52B in order to reduce torque.

Although not shown, the second sealing member 50 may be provided with a plurality of water discharge protrusions (fins) instead of the lip 38 or in addition to the lip 38. The plurality of water discharge protrusions project from the flange 52B of the rigid ring 52 toward the annular portion 34 of the first seal member 30, and the water in the space 60 is discharged to the outside as the second seal member 50 rotates. do.

An annular first gap 61 is provided between the cylindrical portion 33 of the first sealing member 30 and the outer edge of the flange 53 of the second sealing member 50 (in this embodiment, the outer peripheral edge portion 51B of the elastic ring 51). Is provided.

Further, an annular second gap 62 is provided between the protruding portion 35 of the first sealing member 30 and the flange 53 of the second sealing member 50 (in this embodiment, the thin plate portion 51C of the elastic ring 51). ing. That is, the protruding portion 35 does not come into contact with the second seal member 50, does not give a sliding resistance force to the second seal member 50, and does not contribute to the increase in torque. The second gap 62 connects the first gap 61 and the space 60.

In this embodiment, the first gap 61 is a short columnar shape, and the second gap 62 is a disk shape on a plane orthogonal to the central axis Ax of the hub bearing 1. Therefore, the second gap 62 is orthogonal to the first gap 61.

With the relative rotation of the inner ring 6 and the outer ring 8, the water in the space 60 between the annular portion 34 of the first sealing member 30 and the flange 53 of the second sealing member 50 becomes the second gap 62 and the first. It is promptly discharged to the outside through the gap 61 of. Further, if the width A of the second gap 62 is small and the length B of the second gap 62 is large, the intrusion of water from the outside into the space 60 is suppressed.

The inventor conducted a test for confirming the effect of suppressing water intrusion with respect to this embodiment. FIG. 3 shows the test equipment used for this test. This test apparatus has a rotating shaft 70, a housing 72, a first sealing member 74, and a second sealing member 50.

The rotating shaft 70 is a solid round bar that mimics the inner ring 6. The rotating shaft 70 is rotated around a horizontally arranged central axis by a motor (not shown).

A rotary shaft 70 is press-fitted into the sleeve 52A of the second seal member 50, and the second seal member 50 is fixed to the rotary shaft 70. Therefore, the second seal member 50 rotates together with the rotation shaft 70.

The first seal member 74 mimics the first seal member 30, but does not have an axial lip 38.

The housing 72 mimics the outer ring 8. The housing 72 has a hole 72A in which the rotating shaft 70 is arranged. The cylindrical portion 33 of the first sealing member 74 is press-fitted into the hole 72A of the housing 72, and the first sealing member 74 is fixed to the housing 72.

Although not shown, a wall is provided at the left end of the housing 72, and a storage space 76 capable of storing water is provided between the wall and the flange 53 of the second sealing member 50.

In the test, a combination (that is, a plurality of test devices) of a plurality of first sealing members 74 and a second sealing member 50 having different widths A and lengths B of the second gap 62 was prepared. The width A of the second gap 62 was changed to three values. The length B of the second gap 62 was 1.0 mm, 1.5 mm, and 2.0 mm. In each test apparatus, the width C of the first gap 61 was 0.3 mm.

Then, the rotation shaft 70 and the second seal member 50 were rotated and maintained at a rotation speed of 1000 rpm.

Water was allowed to flow into the storage space 76 in a steady state at a rotation speed of 1000 rpm, and the level of the water surface was adjusted to the height of the central axis of the rotation shaft 70.

Below the central axis of the rotating shaft 70, water flowed from the storage space 76 through the first gap 61 toward the second gap 62 and the space 60. Twenty minutes after adjusting the level of the water surface to the height of the central axis of the rotating shaft 70, the water intrusion height H was measured. The height H was the height from the lowest level of the inner peripheral surface of the cylindrical portion 33.

FIG. 4 shows the results of this test. From the test results, it was confirmed that the smaller the width A of the second gap 62, the smaller the water intrusion height H, and the larger the length B of the second gap 62, the smaller the water intrusion height H. Was done.

More specifically, when the width A of the second gap 62 is the smallest value in the test, the water penetration height H is almost the same in all the test devices having different lengths B of the second gap 62. Met.

When the width A of the second gap 62 is a larger value and the length B of the second gap 62 is 1.0 mm or 1.5 mm, the water penetration height H is the second. It was larger than the length B of the gap 62 of 2. That is, the water penetrated into the space 60 beyond the second gap 62.

However, when the length B of the second gap 62 is 2.0 mm, the water penetration height H is the second in any of the test devices having different lengths B of the second gap 62. It was smaller than the length B of the gap 62. That is, the water stayed in the second gap 62 and did not penetrate into the space 60.

In short, from the results of the test, it was found that when the width A of the second gap 62 is 0.85 mm or less, the length B of the second gap 62 is preferably 2 mm.

It is considered that the smaller the width A of the second gap 62, the more the intrusion of water is suppressed, and the larger the length B of the second gap 62, the more the invasion of water is suppressed. Therefore, it is considered that there is no lower limit in the preferable range of the width A of the second gap 62, and there is no upper limit in the preferable range of the length B of the second gap 62 of 2 mm.

From the above, it is preferable that the width A of the second gap 62 is 0.85 mm or less and the length B of the second gap 62 is 2 mm or more.

FIG. 5 shows a sealing device 21 according to a modified example of the first embodiment.

In this modification, an annular protruding wall 51D protruding toward the outboard is formed on the thin plate portion 51C of the elastic ring 51 of the second sealing member 50. In addition to the thick plate portion 51A, the outer peripheral edge portion 51B, and the thin plate portion 51C, the protruding wall 51D can be regarded as a portion of the flange 53. The radial outer surface of the protruding wall 51D is curved.

In this modification, the corner portion of the protruding portion 35 of the first sealing member 30 is curved in the same manner as the radial outer surface of the protruding wall 51D. A curved annular first portion between the corner portion of the protruding portion 35 of the first sealing member 30 and the flange 53 of the second sealing member 50 (in this modified example, the thin plate portion 51C of the elastic ring 51 and the protruding wall 51D). A gap 62 of 2 is provided. The protruding portion 35 does not come into contact with the second seal member 50, does not give a sliding resistance force to the second seal member 50, and does not contribute to an increase in torque.

The curved annular second gap 62 is bent 90 degrees in the middle. Of the second gap 62, the portion adjacent to the first gap 61 has a disk shape on a plane orthogonal to the central axis Ax of the hub bearing 1, and this portion is a short columnar first gap. Orthogonal to 61.

With the relative rotation of the inner ring 6 and the outer ring 8, the water in the space 60 between the annular portion 34 of the first sealing member 30 and the flange 53 of the second sealing member 50 becomes the second gap 62 and the first. It is promptly discharged to the outside through the gap 61 of. Further, if the width A of the second gap 62 is small and the length B of the second gap 62 is large, the intrusion of water from the outside into the space 60 is suppressed.

Also in this modified example, it is preferable that the width A of the second gap 62 is 0.85 mm or less and the length B of the second gap 62 is 2 mm or more.

In this modification, the protruding wall 51D is part of the elastic ring 51. However, the protruding wall 51D may be formed as a member separate from the elastic ring 51 and joined to the flange 52B of the rigid ring 52. In this case, the protruding wall 51D may be formed of a material different from the elastic ring 51, for example, a resin.

FIG. 6 shows a sealing device 21 according to another modification of the first embodiment. In this modification, the elastic ring 51 of the second sealing member 50 does not have the outer peripheral edge portion 51B and the thin plate portion 51C.

An annular first edge between the cylindrical portion 33 of the first sealing member 30 and the outer edge of the flange 53 of the second sealing member 50 (in this modification, the outer edge of the flange 52B of the rigid ring 52). A gap 61 is provided.

An annular disc-shaped second gap 62 is provided between the protrusion 35 of the first sealing member 30 and the flange 53 of the second sealing member 50 (flange 52B of the rigid ring 52 in this modification). Has been done. The protruding portion 35 does not come into contact with the second seal member 50, does not give a sliding resistance force to the second seal member 50, and does not contribute to an increase in torque.

In this embodiment, the first gap 61 is a short columnar shape, and the second gap 62 is a disk shape on a plane orthogonal to the central axis Ax of the hub bearing 1. Therefore, the second gap 62 is orthogonal to the first gap 61.

With the relative rotation of the inner ring 6 and the outer ring 8, the water in the space 60 between the annular portion 34 of the first sealing member 30 and the flange 53 of the second sealing member 50 becomes the second gap 62 and the first. It is promptly discharged to the outside through the gap 61 of. Further, if the width A of the second gap 62 is small and the length B of the second gap 62 is large, the intrusion of water from the outside into the space 60 is suppressed.

Also in this modified example, it is preferable that the width A of the second gap 62 is 0.85 mm or less and the length B of the second gap 62 is 2 mm or more.

Second Embodiment The above first embodiment relates to a sealing device 21 on the inboard side of the hub bearing 1. A second embodiment of the present invention relates to a sealing structure including a sealing device 20 on the outboard side of the hub bearing 1.

As shown in FIG. 7, the sealing device (sealing member) 20 is arranged in the gap between the cylindrical end portion 8A of the outer ring 8 of the hub bearing 1 on the outboard side and the hub 4 of the hub bearing 1. NS.

In the vicinity of the outboard-side end 8A of the outer ring 8, the hub 4 has a cylindrical portion 4A, a flange portion 4B, an arc portion 4C, and a flange portion 4D. The cylindrical portion 4A is located in the vicinity of the ball 10. The flange portion 4B extends radially outward of the cylindrical portion 4A. The arc portion 4C connects the cylindrical portion 4A and the flange portion 4B. The flange portion 4D is arranged radially outside the flange portion 4B, is parallel to the flange portion 4B, and extends radially outside. The flange portion 4B and the flange portion 4D are portions of the outboard side flange 18.

Most of the sealing device 20 is arranged in a space surrounded by the end portion 8A of the outer ring 8, the outer peripheral surface of the cylindrical portion 4A of the hub 4, the flange portion 4B, and the outer peripheral surface of the arc portion 4C. Although the sealing device 20 is annular, only the left side portion thereof is shown in FIG.

The sealing device 20 is a fixed sealing member that is attached to the outer ring 8 and does not rotate. The sealing device 20 has a composite structure having an elastic ring 80 and a rigid ring 81. The elastic ring 80 is made of an elastic material, for example, an elastomer. The rigid ring 81 is made of a rigid body material, for example metal, to reinforce the elastic ring 80. A part of the rigid ring 81 is embedded in the elastic ring 80 and is in close contact with the elastic ring 80.

The sealing device 20 has a cylindrical portion 82, an annular portion 84, an inclined annular portion 86, lips 88, 89, an outer annular portion 90, a cylindrical portion 92, and a protruding portion 94.

The cylindrical portion 82 is fitted (that is, press-fitted) to the inner peripheral surface of the end portion 8A of the outer ring 8 by a tightening method. The cylindrical portion 82 is composed of a rigid ring 81 and an elastic ring 80. Specifically, the rigid ring 81 has a bent portion, and a part of the elastic ring 80 is embedded in the bent portion.

The annular portion 84 is an annular flat plate and is in a plane perpendicular to the axis of the cylindrical portion 4A of the hub 4 and the end portion 8A of the outer ring 8. The annular portion 84 has a portion that is substantially orthogonal to the cylindrical portion 82 and is located radially inside the cylindrical portion 82 and a portion that is located radially outside the cylindrical portion 82. The portion of the annular portion 84 located radially outside the cylindrical portion 82 comes into surface contact with the end surface of the end portion 8A of the outer ring 8. The annular portion 84 is composed of a rigid ring 81 and an elastic ring 80.

The elastic portion of the annular portion 84 faces the flange portion 4B of the outboard side flange 18, and an annular space 100 is provided between the annular portion 84 and the flange portion 4B. In this embodiment, the elastic portion of the annular portion 84 is parallel to the flange portion 4B.

The inclined annular portion 86 is arranged inside the annular portion 84 in the radial direction and is continuous from the annular portion 84. The inclined annular portion 86 is composed of a rigid ring 81 and an elastic ring 80.

The lips 88 and 89 are thin plate-shaped annulus extending from the inner end of the inclined annular portion 86 toward the hub 4 of the hub bearing 1, and the tips of the lips 88 and 89 come into contact with the hub 4. The lips 88 and 89 are composed of an elastic ring 80.

The lip 88 is a radial lip, that is, a grease lip, and extends toward the cylindrical portion 4A of the hub 4, and the tip of the lip 88 contacts the outer peripheral surface 4A of the cylindrical portion. The lip 88 extends radially inward and toward the inboard side, and mainly plays a role of preventing the outflow of the lubricant from the inside of the hub bearing 1.

The lip 89 extends laterally (outboard side) and radially outward from the inclined annular portion 86. The lip 89 is an axial lip or a side lip that extends toward the flange portion 4B of the hub 4 and the tip of the lip 89 contacts the flange portion 4B or the arc portion 4C. The lip 89 mainly plays a role of preventing the inflow of foreign matter from the outside into the inside of the hub bearing 1. Since the hub 4 rotates while the sealing device 20 is attached to the fixed outer ring 8, the lips 88 and 89 slide with respect to the hub 4.

However, the lip 89 is not absolutely essential and can be omitted. When the lip 89 is omitted, the torque applied to the hub 4 by the sealing device 20 is reduced. When the lip 89 is provided, the lip 89 does not have to come into contact with the hub 4 in order to reduce the torque.

Conversely, in addition to the lip 89, additional side lips extending from the inclined annular portion 86 toward the flange portion 4B may be provided.

Although not shown, the hub 4 may be provided with a plurality of water discharge protrusions (fins) instead of the lip 89 or in addition to the lip 89. The plurality of water discharge protrusions project from the flange portion 4B toward the annular portion 84 of the sealing device 20, and the water in the space 100 is discharged to the outside as the hub 4 rotates.

The outer annular portion 90 is arranged radially outside the annular portion 84, is continuous with the annular portion 84, and extends radially outward. The outer annular portion 90 is composed of an elastic ring 80.

The cylindrical portion 92 extends from the boundary between the annular portion 84 and the outer annular portion 90 toward the flange portion 4D of the outboard side flange 18. Therefore, the annular portion 84 is arranged radially inward of the cylindrical portion 92 and extends radially inward toward the cylindrical portion 4A of the hub 4. The cylindrical portion 92 is composed of an elastic ring 80.

The projecting portion 94 is connected to the cylindrical portion 92 and the annular portion 84, projects radially inward from the cylindrical portion 92, and projects from the annular portion 84 toward the outboard side. The cylindrical portion 92 is composed of an elastic ring 80. In this embodiment, the protrusion 94 is an annulus having a rectangular cross section.

The cylindrical portion 92 of the sealing device 20 is arranged on the radial side of the flange portion 4B of the outboard side flange 18. An annular first gap 101 is provided between the cylindrical portion 92 and the outer edge of the flange 4B of the hub 4.

Further, an annular second gap 102 is provided between the protrusion 94 of the sealing device 20 and the flange 4B of the hub 4. That is, the protruding portion 94 does not come into contact with the hub 4, does not give a sliding resistance force to the hub 4, and does not contribute to the increase in torque. The second gap 102 connects the first gap 101 and the space 100.

In this embodiment, the first gap 101 is a short columnar shape, and the second gap 102 is a disk shape on a plane orthogonal to the central axis Ax of the hub bearing 1. Therefore, the second gap 102 is orthogonal to the first gap 101.

With the relative rotation of the hub 4 and the outer ring 8, the water in the space 100 between the annular portion 84 of the sealing device 20 and the flange 4B of the hub 4 is swift to the outside through the second gap 102 and the first gap 101. Is discharged to. Further, if the width of the second gap 102 is small and the length of the second gap 102 is large, the intrusion of water from the outside into the space 100 is suppressed.

Also in this embodiment, it is preferable that the width A of the second gap 102 is 0.85 mm or less and the length B of the second gap 102 is 2 mm or more.

As shown in FIG. 8, the thin plate 103 may be joined to the flange portion 4B of the outboard side flange 18, and between the protruding portion 94 of the sealing device 20 and the thin plate 103 (which can be regarded as a part of the flange 4B). May be provided with a second gap 102. In this case, the thin plate 103 may be formed of any of metal, resin or elastomer. The shape of the thin plate 103 may be changed to provide a curved annular second gap 102 similar to the curved annular second gap 62 of FIG.

Other Modifications Although the present invention has been illustrated and described above with reference to preferred embodiments of the present invention, those skilled in the art will not deviate from the scope of the invention described in the claims and will be described in form and detail. It will be understood that changes are possible. Such changes, modifications and modifications should be within the scope of the present invention.

For example, in the above embodiment, the hub 4 and the inner ring 6 which are inner members are rotating members, and the outer ring 8 which is an outer member is a stationary member. However, the present invention is not limited to the above embodiment, and can be applied to sealing a plurality of members that rotate relative to each other. For example, the inner member may be stationary and the outer member may be rotated, or all of these members may be rotated.

The application of the present invention is not limited to sealing the hub bearing 1. For example, the differential gear mechanism or other power transmission mechanism of an automobile, the bearing or other support mechanism of a drive shaft of an automobile, the bearing of the rotating shaft of a pump or other support mechanism, etc. are also the sealing device or the sealing structure according to the present invention. Can be used.

1 Hub bearing 4 Hub (inner member)
6 Inner ring (inner member)
8 Outer ring (outer member)
18 Outboard side flange 20 Sealing device (sealing member)
21 Sealing device 30 First sealing member 50 Second sealing member 33 Cylindrical portion 34 Circular portion 35 Protruding portion 51 Elastic ring 51A Thick plate portion 51B Outer peripheral edge portion 51C Thin plate portion 52 Rigid ring 52A Sleeve 52B Flange 53 Flange 60 Space 61 First Gap 62 Second Gap 4A Cylindrical Part 4B Flange Part 84 Circular Part 92 Cylindrical Part 94 Protruding Part 100 Space 101 First Gap 102 Second Gap

Claims (2)

A sealing device that is arranged between a relatively rotating inner member and an outer member and seals a gap between the inner member and the outer member.
Attached to the outer member, it has a cylindrical portion, an annular portion, and a protruding portion, and the annular portion is arranged radially inside the cylindrical portion and spreads radially inward toward the inner member, and the protruding portion. A first sealing member, which is connected to the cylindrical portion and the annular portion and projects radially inward from the cylindrical portion and protrudes from the annular portion.
It is attached to the inner member and has a flange, the flange extends outward in the radial direction, and includes a second seal member facing the annular portion of the first seal member.
An annular space is provided between the annular portion of the first sealing member and the flange of the second sealing member.
An annular first gap is provided between the cylindrical portion of the first sealing member and the outer edge of the flange of the second sealing member.
An annular second gap is provided between the protruding portion of the first sealing member and the flange of the second sealing member, and the second gap is formed between the first gap and the space. Connected so that at least a portion of the second gap is orthogonal to the first gap.
The width of the second gap is 0.85 mm or less, and the width of the second gap is 0.85 mm or less.
A sealing device having a length of the second gap of 2 mm or more. An inner member having a columnar portion and a flange extending radially outward of the columnar portion,
An outer member that rotates relative to the inner member,
It is attached to the outer member and has a cylindrical portion, an annular portion, and a protruding portion, and the annular portion is arranged radially inside the cylindrical portion and spreads radially inward toward the cylindrical portion of the inner member. A sealing member is provided, wherein the projecting portion is connected to the cylindrical portion and the annular portion, projects radially inward from the cylindrical portion, and projects from the annular portion.
An annular space is provided between the annular portion of the seal member and the flange of the inner member.
An annular first gap is provided between the cylindrical portion of the sealing member and the outer edge of the flange of the inner member.
An annular second gap is provided between the protrusion of the seal member and the flange of the inner member, and the second gap connects the first gap and the space, and the second gap is connected. At least a part of the gap is orthogonal to the first gap,
The width of the second gap is 0.85 mm or less, and the width of the second gap is 0.85 mm or less.
A sealed structure in which the length of the second gap is 2 mm or more.

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