JP2020133739A - Sealing device - Google Patents

Abstract

To provide a sealing device which has high sealing performance for foreign matters, low torque imparted to a rotating member, high water discharge performance, and also high protection performance from water for a sealing object.SOLUTION: The sealing device sealing a clearance between an inside member and an outside member which relatively rotate with respect to each other comprises a first seal member attached to the outside member, and a second seal member attached to the inside member. The second seal member has a plurality of water discharge protrusions, and the water discharge protrusions are protruded toward an annular portion of the first seal member, and aligned in a circumferential direction. The second seal member has circumferential protrusions continuing in a peripheral direction, and the circumferential protrusions are protruded toward the annular portion of the first seal member, and located outside in a radial direction rather than the water discharge protrusions. The first seal member has an annular labyrinth lip continuing in the peripheral direction, and the labyrinth lip protrudes toward a flange portion of the second seal member, does not contact with the second seal member, and is arranged in a clearance between the water discharge protrusions and the circumferential protrusions.SELECTED DRAWING: Figure 2

Description

The present invention relates to a sealing device.

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 has a mounting ring that is press-fitted into the outer ring of the rolling bearing, a seal ring that is integrally provided on the mounting ring, and a slinger that is mounted on the inner ring, and a plurality of lips formed on the seal ring are slinger. Contact. The plurality of lips have a function of sealing the lubricant (grease) inside the bearing and a function of sealing the foreign matter such as water and dust from the outside so as not to enter the inside of the bearing.

Japanese Unexamined Patent Publication No. 2005-331002

While this type of sealing device is required to have high sealing performance against foreign matter, it is required to reduce the torque applied to the rotating shaft.

In addition, for this type of sealing device, when used in an environment with a lot of water (including muddy water or salt water), enhance the function of protecting water from entering the inside of the sealed object (for example, bearing). Is required. 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 having high sealing performance against foreign matter, small torque applied to a rotating member, high water discharge performance, and high protection performance from water to a sealing target.

The sealing device according to an aspect of the present invention is 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. A first seal member attached to the outer member and having an annular portion, the annular portion extending radially inward toward the inner member, and a flange portion attached to the inner member. The flange portion extends outward in the radial direction, and includes a second sealing member facing the annular portion of the first sealing member. The second seal member has a plurality of water discharge protrusions, and the plurality of water discharge protrusions project from the flange portion toward the annular portion of the first seal member and are spaced from each other. They are arranged in the circumferential direction. The second sealing member has a circumferential protrusion that is continuous in the circumferential direction, and the circumferential protrusion projects from the flange portion toward the annular portion of the first sealing member to discharge the water. It is arranged radially outside the protrusion. The first sealing member has an annular labyrinth slip that is continuous in the circumferential direction, and the labyrinth slip projects from the annular portion toward the flange portion of the second sealing member, and the second sealing member. It is arranged in the gap between the plurality of water discharge protrusions and the circumferential protrusion of the second seal member without contacting the seal member.

In this sealing device, water may enter the space between the annular portion of the first sealing member and the flange portion of the second sealing member. However, a plurality of water discharge protrusions protrude in this space, and the water in the space flows along the water discharge protrusions and is promptly discharged from the space as the inner member and the outer member rotate relative to each other. .. Therefore, the sealing device has high protection performance from water to the sealed object. Further, a circumferential protrusion is arranged on the radial outer side of the plurality of water discharge protrusions, and a labyrinth slip is arranged in the gap between the plurality of water discharge protrusions and the circumferential protrusion, and the circumferential protrusion and the labyrinth are arranged. The lip blocks the entry of foreign matter from the outside. That is, since the circumferential protrusion, the labyrinth slip, and the water discharge protrusion overlap in the radial direction, the intrusion route of foreign matter from the outside becomes complicated, and the sealing performance against foreign matter is improved. The foreign matter blocked by the circumferential protrusion, the labyrinth slip, or the water discharge protrusion is discharged along the water discharge protrusion by the centrifugal force caused by the relative rotation of the inner member and the outer member. The labyrinth slip provided on the first sealing member does not come into contact with the second sealing member. Therefore, the torque applied to the rotating member (that is, at least one of the inner member and the outer member) is small.

It is a partial cross-sectional view of an example of a rolling bearing in which the sealing device which concerns on embodiment of this invention is used. It is a partial cross-sectional view of the sealing device which concerns on 1st Embodiment of this invention. It is a front view of the 2nd sealing member of the sealing device which concerns on 1st Embodiment. It is a partial cross-sectional view of the sealing device corresponding to the cross section taken along the line IV-IV of FIG. It is a perspective view of the 2nd sealing member of the sealing device which concerns on 1st Embodiment. It is a partial cross-sectional view of the sealing device which concerns on 1st 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 that projects 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. Stop. 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.

As shown in FIG. 2, the sealing device 21 is arranged in the gap between the inboard-side end 8B of the outer ring 8 of the hub bearing 1 and the 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. As is clear from FIG. 2, the sealing device 22 has a composite structure including the first sealing member 24 and the second sealing member 26.

The first seal member 24 is a fixed seal member that is attached to the outer ring 8 and does not rotate. The first sealing member 24 has a composite structure having an elastic ring 28 and a rigid ring 30. The elastic ring 28 is made of an elastic material, for example, an elastomer. The rigid ring 30 is made of a rigid material, for example metal, to reinforce the elastic ring 28. The rigid ring 30 has a substantially L-shaped cross section. A part of the rigid ring 30 is embedded in the elastic ring 28 and is in close contact with the elastic ring 28.

The first sealing member 24 has a cylindrical portion 24A, an annular portion 24B, and radial lips 24C, 24D. The cylindrical portion 24A constitutes a mounting portion to be mounted on the outer ring 8. Specifically, the cylindrical portion 24A is fitted (that is, press-fitted) into the end portion 8B of the outer ring 8 by a tightening method. The annular portion 24B is an annular shape, is arranged radially inward of the cylindrical portion 24A, and extends radially inward toward the inner ring 6. The cylindrical portion 24A and the annular portion 24B are composed of a rigid ring 30 and an elastic ring 28.

The radial lips 24C and 24D extend from the inner end of the annular portion 24B toward the second sealing member 26, and the tips of the radial lips 24C and 24D come into contact with the second sealing member 26. The radial lips 24C and 24D are composed of an elastic ring 28.

The second seal member 26 can also be called a slinger, that is, a rotary seal member. The second seal member 26 is attached to the inner ring 6, and when the inner ring 6 rotates, the second seal member 26 rotates together with the inner ring 6 to bounce off foreign matter scattered from the outside.

In this embodiment, the second sealing member 26 also has a composite structure having an elastic ring 32 and a rigid ring 34. The rigid ring 34 is made of a rigid material, for example metal.

The rigid ring 34 has a substantially L-shaped cross section. Specifically, it includes a cylindrical sleeve portion 34A and an annular flange portion 34B extending radially outward from the sleeve portion 34A. The sleeve portion 34A constitutes a mounting portion to be attached to the inner ring 6. Specifically, the end portion of the inner ring 6 is fitted (that is, press-fitted) into the sleeve portion 34A by a tightening method.

The flange portion 34B is arranged radially outside the sleeve portion 34A, extends radially outward, and faces the annular portion 24B of the first seal member 24. In this embodiment, the flange portion 34B is a flat plate and is in a plane perpendicular to the axis of the sleeve portion 34A.

The elastic ring 32 is in close contact with the flange portion 34B of the rigid ring 34. In this embodiment, the elastic ring 32 is provided to measure the rotational speed of the inner ring 6. Specifically, the elastic ring 32 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 elastic ring 32, 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 32 can be measured by a magnetic rotary encoder (not shown). Since the material of the elastic ring 32 contains metal powder, it has a higher hardness than a normal elastomer material and is not easily damaged by foreign matter.

The radial lip 24C of the first sealing member 24 is a grease lip extending inward in the radial direction from the inner end of the annular portion 24B. The grease lip 24C extends toward the sleeve portion 34A of the second sealing member 26, and the tip of the grease lip 24C contacts the sleeve portion 34A. The grease lip 24C extends inward in the radial direction and toward the outboard side, and mainly serves to prevent the outflow of the lubricant from the inside of the hub bearing 1.

The radial lip 24D is a dust strip that extends laterally from the medial end of the annular portion 24B. The dust strip 24D extends radially outward and inboard. The dust strip 24D also extends toward the sleeve portion 34A of the second sealing member 26, and the tip of the dust strip 24D contacts the sleeve portion 34A. The dust strip 24D 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 26 rotate while the first seal member 24 is attached to the fixed outer ring 8, each of the radial lips 24C and 24D is a sleeve portion of the second seal member 26. It slides with respect to 34A.

An annular gap 36 is provided between the inboard-side tip of the cylindrical portion 24A of the first seal member 24 and the outer edge of the second seal member 26. Foreign matter may enter the space 38 between the annular portion 24B of the first sealing member 24 and the flange portion 34B of the second sealing member 26 through the gap 36. On the contrary, the foreign matter in the space 38 can be discharged through the gap 36.

FIG. 3 is a front view of the second sealing member 26, and FIG. 4 is a partial cross-sectional view of the sealing device 21 corresponding to the cross section taken along the line IV-IV of FIG. FIG. 2 is a cross-sectional view of the sealing device 21 as viewed along the line II-II of FIG. FIG. 5 is a perspective view of the second seal member 26.

As shown in FIGS. 2 to 5, the second seal member 26 has a plurality of water discharge protrusions 40 protruding from the flange portion 34B toward the annular portion 24B of the first seal member 24. These water discharge protrusions 40 have the same shape and size, and are arranged at equal intervals in the circumferential direction. As shown in FIG. 2, these water discharge protrusions 40 are supported by the flange portion 34B, and the space 38 between the annular portion 24B of the first sealing member 24 and the flange portion 34B of the second sealing member 26. Protruding inward.

In this embodiment, the plurality of water discharge protrusions 40 are integrally attached to the portion of the elastic ring 32 that covers the surface 34C of the flange portion 34B facing the annular portion 24B. That is, the water discharge protrusion 40 is a portion of the elastic ring 32. Therefore, the water discharge protrusion 40 is formed of the same material as the elastic ring 32, that is, an elastomer material containing magnetic metal powder and ceramic powder. However, the water discharge protrusion 40 may be formed of a rigid material, and in this case, the water discharge protrusion 40 may be integrally formed with the flange portion 34B.

In this embodiment, as shown in FIG. 3, each water discharge protrusion 40 has a substantially quadrangular contour, specifically a substantially parallelogram contour when viewed along the axial direction of the second sealing member 26. Have. More specifically, as shown in FIG. 3, each water discharge protrusion 40 has two side surfaces 40A and 40B inclined with respect to the circumferential direction and the radial direction of the second seal member 26. The side surfaces 40A and 40B of each water discharge protrusion 40 are substantially parallel to each other.

In FIG. 3, the arrow R1 indicates the rotation direction (rotation direction of the inner ring 6) of the second seal member 26 when the automobile provided with the hub bearing 1 is moving forward. The side surface 40A of the water discharge protrusion 40 intersects the rotation direction R1 at an acute angle, and the side surface 40B intersects the rotation direction R1 at an obtuse angle.

However, as a modification, as shown in the circle A of FIG. 3, each water discharge protrusion 40 has two side surfaces 40A extending along the radial direction of the second seal member 26 (perpendicular to the circumferential direction). , 40B may have. The circle A in FIG. 3 corresponds to the area surrounded by the circle of the virtual line. In this case, the distance between the inclined side surfaces 40A and 40B of each water discharge protrusion 40 becomes smaller toward the inner side in the radial direction of the second seal member 26.

Alternatively, as another modification, as shown in the circle B of FIG. 3, each water discharge protrusion 40 has a substantially trapezoidal contour when viewed along the axial direction of the second seal member 26. May be good. The circle B in FIG. 3 corresponds to the area surrounded by the circle of the virtual line. In this case, the distance between the inclined side surfaces 40A and 40B of each water discharge protrusion 40 becomes smaller toward the outer side in the radial direction of the second seal member 26. Although not shown, each water discharge protrusion 40 may have a substantially isosceles triangular contour when viewed along the axial direction of the second seal member 26.

As shown in FIGS. 2 and 4, each water discharge protrusion 40 has a cross-sectional shape that tapers from the flange portion 34B toward the tip when viewed from the side of the second sealing member 26, and is inclined or inclined. It has a curved outer peripheral surface 40C. The outer peripheral surface 40C is inclined or curved so as to be located radially outward as the distance from the annular portion 24B of the first sealing member 24 increases.

The second seal member 26 further has a circumferential protrusion 42 that is continuous in the circumferential direction. The circumferential protrusion 42 projects from the flange portion 34B toward the annular portion 24B of the first sealing member 24. The circumferential protrusion 42 is arranged radially outside the water discharge protrusion 40. In this embodiment, the circumferential protrusion 42 is provided on the outermost edge of the second seal member 26.

In this embodiment, the circumferential protrusion 42 is integrally attached to the portion of the elastic ring 32 that covers the surface 34C of the flange portion 34B facing the annular portion 24B. That is, the circumferential protrusion 42 is a portion of the elastic ring 32. Therefore, the circumferential protrusion 42 is formed of the same material as the elastic ring 32, that is, an elastomer material containing magnetic metal powder and ceramic powder. However, the circumferential protrusion 42 may be formed of a rigid material, and in this case, the circumferential protrusion 42 may be integrally formed with the flange portion 34B.

The circumferential protrusion 42 has a cross-sectional shape that tapers from the flange portion 34B toward the tip. Specifically, in this embodiment, the inner peripheral surface of the circumferential protrusion 42 has a larger diameter as the distance from the flange portion 34B, and the outer peripheral surface of the circumferential protrusion 42 has a smaller diameter as the distance from the flange portion 34B. Have.

On the other hand, the annular portion 24B of the first sealing member 24 on which the water discharge protrusion 40 and the circumferential protrusion 42 face each other is roughly (except for the labyrinth slip 46 described later) in the radial direction toward the inboard side. It is located on the outside and has a surface that reaches the inner peripheral surface of the cylindrical portion 24A. More specifically, the annular portion 24B has a substantially truncated cone-shaped inner peripheral surface 44 that is inclined or curved so as to be located radially outward toward the flange portion 34B of the second sealing member 26. The outer peripheral surfaces 40C of the plurality of water discharge protrusions 40 face each other on the inner peripheral surface 44, and a narrow gap is provided between the inner peripheral surface 44 and the outer peripheral surface 40C.

The first sealing member 24 further has an annular labyrinth slip 46 that is continuous in the circumferential direction. The labyrinth slip 46 projects from the annular portion 24B toward the flange portion 34B of the second sealing member 26, does not come into contact with the second sealing member 26, and has a plurality of water discharge protrusions 40 and a circle of the second sealing member 26. It is arranged in the gap between the peripheral protrusions 42.

The labyrinth slip 46 has a truncated cone shape that projects obliquely outward in the radial direction from the annular portion 24B. The inner peripheral surface of the labyrinth slip 46 is flush with the inner peripheral surface 44 (that is, smoothly connected to the inner peripheral surface 44), and is inclined so as to be located radially outward toward the flange portion 34B. There is. The outer peripheral surface of the labyrinth slip 46 is also inclined so as to be located radially outward toward the flange portion 34B.

The cylindrical portion 24A of the first sealing member 24 is arranged radially outside the flange portion 34B of the second sealing member 26 and the circumferential protrusion 42. At least a part of the inner peripheral surface of the cylindrical portion 24A is inclined so that the diameter becomes larger toward the inboard side, and there is a substantially uniform distance between this portion and the circumferential protrusion 42 of the second sealing member 26. A slope gap 48 is provided. The inclined gap 48 is inclined so as to be located radially outward as the distance from the annular portion 24B increases.

As shown in FIGS. 2 and 4, the water discharge protrusion 40 and the circumferential protrusion 42 of the first seal member 24 do not come into contact with the second seal member 26, and the labyrinth slip 46 of the second seal member 26 , Does not come into contact with the first seal member 24. Therefore, these do not cause an increase in torque applied to the second seal member 26 and thus the inner ring 6. Further, the water discharge protrusion 40 and the circumferential protrusion 42 do not collide with the second seal member 26, and the labyrinth slip 46 does not collide with the first seal member 24.

As described above, foreign matter (water and dust) is contained in the space 38 (see FIG. 2) between the annular portion 24B of the first sealing member 24 and the elastic ring 32 covering the flange portion 34B of the second sealing member 26. Including) can invade. However, a plurality of water discharge protrusions 40 project into the space 38, and as the inner ring 6 and the outer ring 8 rotate relative to each other, the water in the space 38 flows along the water discharge protrusion 40 and inclines from the space 38. It is promptly discharged through the gap 48 and the gap 36. Therefore, the sealing device 21 has high protection performance from water to the hub bearing 1 to be sealed. As for the sealing device 21 itself, deterioration accelerated by the presence of water (including muddy water or salt water) is reduced. Since the inclined gap 48 and the gap 36 are annular, water flows out from the space 38 through the inclined gap 48 and a part of the gap 36, while the air outside the sealing device 21 flows out from the space 38 through the inclined gap 48 and the gap 36. It flows into the inside of the space 38 through a part of the space 38. The air flowing into the space 38 promotes the outflow of water from the space 38 and prevents the inside of the space 38 from becoming negative pressure to reduce the risk of unexpected deformation of the lips 24C and 24D. To do.

Circumferential protrusions 42 are arranged on the radial outer side of the plurality of water discharge protrusions 40, and labyrinth slips 46 are arranged in the gaps between the plurality of water discharge protrusions 40 and the circumferential protrusions 42. 42 and the labyrinth slip 46 block the invasion of foreign matter from the outside. That is, since the circumferential protrusion 42, the labyrinth slip 46, and the water discharge protrusion 40 overlap in the radial direction, the intrusion route of foreign matter from the outside becomes complicated, and the sealing performance against foreign matter is improved. The foreign matter blocked by any of the circumferential protrusion 42, the labyrinth slip 46, and the water discharge protrusion 40 has an inclined gap 48 along the water discharge protrusion 40 due to the centrifugal force caused by the relative rotation of the inner ring 6 and the outer ring 8. It is discharged through the gap 36.

By providing the radial lips 24C and 24D on the first sealing member 24, it is possible to increase the certainty of blocking foreign matter. As described above, since the sealing device 21 has high foreign matter discharging performance by the water discharge protrusion 40, it is not necessary to increase the contact pressure of the radial lips 24C and 24D with respect to the sleeve portion 34A of the second sealing member 26. Therefore, it is possible to suppress or reduce the torque caused by the radial lips 24C and 24D sliding on the second seal member 26 while improving the water discharge performance.

As described above, since the sealing device 21 has a high discharge performance of foreign matter by the water discharge protrusion 40, the first sealing member 24 is a portion of the second sealing member 26 that comes into contact with the flange portion 34B, for example, a foreign matter. It does not have an axial lip to prevent intrusion. Therefore, it is possible to eliminate the torque caused by the portion of the first seal member 24 sliding on the second seal member 26. Therefore, the energy efficiency of the automobile can be improved.

As described above, the inner peripheral surface 44 of the annular portion 24B of the first sealing member 24 has a truncated cone shape, and the labyrinth slip 46 on the extension line of the inner peripheral surface 44 faces radially outward from the annular portion 24B. It has a truncated cone shape that projects diagonally. Therefore, due to the centrifugal force caused by the relative rotation of the inner ring 6 and the outer ring 8, the foreign matter moves along the inner peripheral surface 44 of the annular portion 24B and reaches the inner peripheral surface of the labyrinth slip 46 smoothly connected to the inner peripheral surface 44. It is discharged promptly along. Further, after the relative rotation is stopped, the foreign matter moves along the inner peripheral surface 44 of the annular portion 24B due to gravity, and is promptly discharged along the inner peripheral surface of the labyrinth slip 46 smoothly connected to the inner peripheral surface 44. (This effect can be clearly understood by rotating FIGS. 2 and 4 90 degrees counterclockwise).

Further, the circumferential protrusion 42 has a cross-sectional shape that tapers from the flange portion 34B toward the tip end. Therefore, due to the centrifugal force caused by the relative rotation of the inner ring 6 and the outer ring 8, the foreign matter is promptly discharged along the tapered circumferential protrusion 42. Further, after the relative rotation is stopped, the foreign matter is promptly discharged along the tapered circumferential protrusion 42 by gravity (when FIGS. 2 and 4 are rotated 90 degrees counterclockwise, this effect is clearly shown. You can understand).

Further, an inclined gap 48 is provided between the cylindrical portion 24A of the first sealing member 24 and the circumferential protrusion 42 of the second sealing member 26, and the inclined gap 48 is radially outward as the distance from the annular portion 24B increases. It is tilted to be located. Therefore, the foreign matter is promptly discharged along the inclined gap 48 due to the centrifugal force caused by the relative rotation of the inner ring 6 and the outer ring 8. Further, after the relative rotation is stopped, the foreign matter is quickly discharged along the inclination gap 48 by gravity (this effect can be clearly understood by rotating FIGS. 2 and 4 90 degrees counterclockwise. ).

In this embodiment, as shown in FIG. 3, the length of each water discharge protrusion 40 in the rotation direction of the inner ring 6 is such that each water discharge in the radial direction of the first seal member 24 and the second seal member 26. It is larger than the length of the protrusion 40. Therefore, even if a hard foreign object collides with the water discharge protrusion 40 and the water discharge protrusion 40 is damaged or the water discharge protrusion 40 is worn by the water flow, the entire water discharge protrusion 40 does not disappear in a short period of time. .. That is, the water discharge protrusion 40 has a long life.

In this embodiment, each water discharge protrusion 40 projects into the space 38 between the annular portion 24B of the first seal member 24 and the flange portion 34B of the second seal member 26. Therefore, as is clear from FIGS. 2 and 4, the plurality of water discharge protrusions 40 are arranged within the range of the maximum diameter of the first sealing member 24. Therefore, it is not necessary to increase the size of the sealing device 21 and thus the hub bearing 1.

In this embodiment, the water discharge protrusion 40 and the circumferential protrusion 42 are formed of the same material as the elastic ring 32, that is, an elastomer material containing magnetic metal powder and ceramic powder. Since the water discharge protrusion 40 contains metal powder and ceramic powder, it has high durability against the impact of a hard foreign substance and high wear resistance.

In this embodiment, the water discharge protrusion 40 and the circumferential protrusion 42 are integrally attached to the elastic ring 32 that covers the flange portion 34B of the rigid ring 34 of the second seal member 26. Therefore, since the number of parts is reduced, the sealing device 21 can be easily assembled.

The method for forming the water discharge protrusion 40 and the circumferential protrusion 42 may be, for example, press working or injection molding using a mold. In this case, the elastic ring 32 is formed and the water discharge protrusion 40 and the circumferential protrusion 42 are formed at the same time. May be formed. However, the water discharge protrusion 40 and the circumferential protrusion 42 may be joined to the flange portion 34B by adhesion, or the water discharge protrusion 40 and the circumferential protrusion 42 may be formed by cutting the elastic ring 32.

The second embodiment FIG. 6 is a partial cross-sectional view showing the sealing device 21 according to the second embodiment of the present invention. In FIG. 6, the same reference numerals are used to show the components already described, and these components will not be described in detail.

In this embodiment, the first sealing member 24 further comprises an annular second labyrinth slip 50. The second labyrinth slip 50 projects from the annular portion 24B toward the flange portion 34B of the second seal member 26, but does not come into contact with the second seal member 26. The second labyrinth slip 50 is composed of an elastic ring 28. The second labyrinth slip 50 overlaps the plurality of water discharge protrusions 40 in the radial direction, and is arranged radially inside the plurality of water discharge protrusions 40.

Since the second labyrinth slip 50 overlaps the plurality of water discharge protrusions 40 in the radial direction, the entry path of foreign matter from the outside becomes more complicated, and the sealing performance against foreign matter is improved. The second labyrinth slip 50 is provided on the first sealing member 24 and does not come into contact with the second sealing member 26. Therefore, the second labyrinth slip 50 does not become a factor for increasing the torque applied to the second seal member 26 and thus the inner ring 6. The second labyrinth slip 50 is arranged radially inside the plurality of water discharge protrusions 40, and the foreign matter blocked by the second labyrinth slip 50 accompanies the relative rotation of the inner ring 6 and the outer ring 8. , Is discharged from the space 42 along the inclined side surface of the water discharge protrusion 40.

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 be able to describe the form and details without departing from the scope of the invention. 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 rotate, or all of these members may rotate.

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

Although the rigid ring 30 of the sealing device 21 of the embodiment is a single component, the rigid ring 30 may be replaced with a plurality of rigid rings separated from each other in the radial direction.

Aspects of the invention are also described in the numbered clauses below.

Clause 1. 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.
A first seal member that is attached to the outer member, has an annular portion, and the annular portion extends radially inward toward the inner member.
It is attached to the inner member and has a flange portion, and the flange portion extends outward in the radial direction and includes a second seal member facing the annular portion of the first seal member.
The second seal member has a plurality of water discharge protrusions, and the plurality of water discharge protrusions project from the flange portion toward the annular portion of the first seal member and are spaced from each other. They are arranged in the circumferential direction,
The second sealing member has a circumferential protrusion that is continuous in the circumferential direction, and the circumferential protrusion projects from the flange portion toward the annular portion of the first sealing member to discharge the water. It is arranged radially outside the protrusion,
The first sealing member has an annular labyrinth slip that is continuous in the circumferential direction, and the labyrinth slip projects from the annular portion toward the flange portion of the second sealing member, and the second sealing member. A sealing device, which is arranged in a gap between the plurality of water discharge protrusions and the circumferential protrusion of the second sealing member without contacting the sealing member.

Clause 2. The sealing device according to Clause 1, wherein the labyrinth slip has a truncated cone shape that projects obliquely outward in the radial direction from the annular portion.

According to this clause, the centrifugal force caused by the relative rotation of the inner member and the outer member promptly discharges the foreign matter along the obliquely protruding labyrinth slip. Further, after the relative rotation is stopped, the foreign matter is promptly discharged along the labyrinth slip that protrudes diagonally due to gravity.

Clause 3. The sealing according to Clause 2, wherein the annular portion of the first sealing member has a truncated cone-shaped inner peripheral surface, and the inner peripheral surface is smoothly connected to the inner peripheral surface of the labyrinth slip. apparatus.

According to this clause, due to the centrifugal force caused by the relative rotation of the inner member and the outer member, the foreign matter moves along the inner peripheral surface of the annular portion and smoothly connects to the inner peripheral surface of the labyrinth slip. It is discharged promptly along. Further, after the relative rotation is stopped, the foreign matter is promptly discharged along the inner peripheral surface of the annular portion and the inner peripheral surface of the labyrinth slip due to gravity.

Clause 4. The sealing device according to any one of Articles 1 to 3, wherein the circumferential protrusion has a cross-sectional shape that tapers from the flange portion toward the tip end.

According to this clause, the centrifugal force caused by the relative rotation of the inner and outer members causes the foreign matter to be quickly expelled along the tapered circumferential projections. Further, after the relative rotation is stopped, the foreign matter is promptly discharged along the tapered circumferential protrusion due to gravity.

Clause 5. The first sealing member has a cylindrical portion arranged outside the annular portion.
The cylindrical portion is arranged on the radial outer side of the flange portion of the second sealing member and the circumferential protrusion, and an inclined gap is provided between the cylindrical portion and the circumferential protrusion. The sealing device according to any one of Articles 1 to 4, wherein the sealing device is inclined so as to be located radially outward as the distance from the annular portion is increased.

According to this clause, the foreign matter is promptly discharged along the inclined gap by the centrifugal force caused by the relative rotation of the inner member and the outer member. Further, after the relative rotation is stopped, the foreign matter is promptly discharged along the inclined gap by gravity.

1 Hub bearing 2 holes 4 Hub (inner member)
6 Inner ring (inner member)
8 Outer ring (outer member)
21 Sealing device 24 First sealing member 24A Cylindrical part 24B Circular part 24C, 24D Radial lip 26 Second sealing member 34A Sleeve part 34B Flange part 40 Water discharge protrusion 42 Circumferential protrusion 44 Inner peripheral surface 46 Labyrinth slip 48 Inclined gap 50 Second labyrinth slip

Claims (5)

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.
A first seal member that is attached to the outer member, has an annular portion, and the annular portion extends radially inward toward the inner member.
It is attached to the inner member and has a flange portion, and the flange portion extends outward in the radial direction and includes a second seal member facing the annular portion of the first seal member.
The second seal member has a plurality of water discharge protrusions, and the plurality of water discharge protrusions project from the flange portion toward the annular portion of the first seal member and are spaced from each other. They are arranged in the circumferential direction,
The second sealing member has a circumferential protrusion that is continuous in the circumferential direction, and the circumferential protrusion projects from the flange portion toward the annular portion of the first sealing member to discharge the water. It is arranged radially outside the protrusion,
The first sealing member has an annular labyrinth slip that is continuous in the circumferential direction, and the labyrinth slip projects from the annular portion toward the flange portion of the second sealing member, and the second sealing member. A sealing device, which is arranged in a gap between the plurality of water discharge protrusions and the circumferential protrusion of the second sealing member without contacting the sealing member. The sealing device according to claim 1, wherein the labyrinth slip has a truncated cone shape that projects obliquely outward in the radial direction from the annular portion. The second aspect of the present invention, wherein the annular portion of the first sealing member has a truncated cone-shaped inner peripheral surface, and the inner peripheral surface is smoothly connected to the inner peripheral surface of the labyrinth slip. Sealing device. The sealing device according to any one of claims 1 to 3, wherein the circumferential protrusion has a cross-sectional shape that tapers from the flange portion toward the tip end. The first sealing member has a cylindrical portion arranged outside the annular portion.
The cylindrical portion is arranged on the radial outer side of the flange portion of the second sealing member and the circumferential protrusion, and an inclined gap is provided between the cylindrical portion and the circumferential protrusion. The sealing device according to any one of claims 1 to 4, wherein the sealing device is inclined so as to be located radially outward as the distance from the annular portion is increased.

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