WO2022244839A1

WO2022244839A1 - Sealing device

Info

Publication number: WO2022244839A1
Application number: PCT/JP2022/020816
Authority: WO
Inventors: 雄一樽川; 一貴廣田
Original assignee: Nok株式会社
Priority date: 2021-05-20
Filing date: 2022-05-19
Publication date: 2022-11-24
Also published as: JPWO2022244839A1

Abstract

Provided is a sealing device in which a torque applied to a rotating member is small and in which the wear of lips and a temperature rise due to frictional heat are suppressed.　A sealing device (20) is disposed between a fixed inner-side member and a rotating outer-side member to seal a gap between the inner-side member and the outer-side member. A first sealing member (30) of the sealing device (20) has a sleeve (31A) mounted to the inner-side member and a flange (31B) expanding radially outward from the sleeve (31A). A second sealing member (40) of the sealing device (20) has a tubular portion (44) disposed on the radially outer side of the flange and mounted to the outer-side member, a disc portion (45) expanding radially inward from the tubular portion (44) and opposed to the flange (31B), radial lips (46, 47) disposed on the radially inner side of the disc portion (45) in slidable contact with the sleeve (31A), and a side lip (48) extending from the disc portion (45) toward the flange (31B). The side lip (48) of the second sealing member (40) is brought into slidable contact with the flange (31B) when the rotational speed of the outer-side member is lower than a threshold value and is deformed so as to be apart from the flange (31B) when the rotational speed of the outer-side member is higher than the threshold value.

Description

sealing device

The present invention relates to a sealing device.

The hub of an automobile is equipped with a rolling bearing that supports the axle. This rolling bearing is called a hub bearing. A sealing device is provided between the inner ring and the outer ring of the hub bearing. This sealing device seals lubricant (grease) inside the bearing and prevents foreign substances such as water and dust from entering the bearing from the outside.

There are two types of hub bearings: inner ring rotating type and outer ring rotating type (Patent Document 1). The inner ring rotating type is a type in which the outer ring is fixed to the vehicle body, and the inner ring and hub fixed to the axle rotate together with the axle. This type is used both when the wheels are driving wheels and when the wheels are driven wheels, as they rotate with the axle. The rotating outer ring type is a type in which the inner ring is fixed to a stationary axle and the outer ring fixed to the wheel rotates together with the wheel. This type is used when the wheel is the driven wheel as the axle is stationary.

WO2015/182357

Some sealing devices provided in hub bearings have a seal member fixed to the outer ring, which is the outer member, and another seal member fixed to the inner ring, which is the inner member. These seal members are brought into slidable contact with each other.

In general, in order to ensure the sealing performance of the sealing device provided in the hub bearing, the lip of the sealing member that comes into slidable contact with other sealing members is designed to have a large interference margin. However, if the lip interference is designed to be large, the contact pressure of the lip and, in turn, the torque applied to the rotating member will increase. In addition, wear of the lip and an increase in temperature due to frictional heat may shorten the life of the sealing device. Sealing devices used in hub bearings with large dimensions have high relative velocities between the inner and outer rings, which increases the risk of lip wear and temperature rise.

Therefore, the present invention provides a sealing device in which the torque applied to the rotating member is small and the temperature rise due to wear of the lip and frictional heat is suppressed.

According to one aspect of the invention, a sealing device is provided between a fixed inner member and a rotating outer member to seal a gap between the inner member and the outer member. The sealing device includes a sleeve attached to the inner member, a first sealing member having a flange extending radially outwardly from the sleeve, and a tubular member disposed radially outwardly of the flange and attached to the outer member. a disc portion extending radially inward from the tubular portion and facing the flange; a radial lip disposed radially inward of the disc portion and slidably contacting the sleeve; a second sealing member having a side lip extending from the portion toward the flange; the side lip of the second seal member slidably contacts the flange when the rotational speed of the outer member is less than a threshold; and when the rotational speed of the outer member is greater than the threshold, Deform away from the flange.

In this aspect, the side lips of the second seal member attached to the rotating outer member slidably contact the flange when the rotational speed of the outer member is less than a threshold value to seal the seal. ensure performance. On the other hand, when the rotational speed of the outer member is greater than the threshold, the side lip of the second sealing member deforms away from the flange due to the centrifugal force on the side lip itself. Therefore, the torque applied to the rotating outer member is small, and the wear of the side lip and temperature rise due to frictional heat are suppressed.

According to one aspect of the invention, a sealing device is provided between a rotating inner member and a fixed outer member to seal a gap between the inner member and the outer member. The sealing device comprises a first seal member attached to the outer member and a second seal member attached to the inner member. The first seal member has a first rigid ring that is an annular member formed of a rigid material around the axis, and the second seal member is formed of a rigid material around the axis. It has a second rigid ring, which is an annular member, and a second elastic ring, which is an annular member formed of an elastic material around the axis. The second elastic ring of the second seal member has a side lip that is an annular portion around the axis extending along the axis. The first rigid ring of the first sealing member is contacted by the tip of the side lip. The side lip of the second seal member slidably contacts the first rigid ring of the first seal member and the inner member when the rotation speed of the inner member is less than a threshold value. is greater than a threshold, the first sealing member is deformed to move away from the first rigid ring.

1 is a partial cross-sectional view of an example of a rolling bearing in which a sealing device according to a first embodiment of the invention is used; FIG. Fig. 4 is a partial cross-sectional view of the sealing device according to the first embodiment of the present invention when the outer member rotates at low speed; FIG. 4 is a partial cross-sectional view of the sealing device according to the first embodiment of the present invention when the outer member rotates at high speed; BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of an example of the in-wheel motor unit in which the sealing device which concerns on the 1st Embodiment of this invention is used. It is a partial cross-sectional view of a sealing device according to a second embodiment of the present invention. FIG. 5 is a cross-sectional view of a rolling bearing fitted with a sealing device according to a second embodiment of the present invention; It is a partial cross-sectional view of a sealing device according to a third embodiment of the present invention. It is a partial sectional view of the sealing device concerning a 4th embodiment of the present invention.

Hereinafter, embodiments according to the present invention will be described with reference to the accompanying drawings. The drawings are not necessarily drawn to scale and some features may be exaggerated or omitted.

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

This hub bearing 1 is of the outer ring rotation type, in which the inner ring is fixed to a stationary axle, and the outer ring fixed to the wheel rotates together with the wheel. The hub bearing 1 includes an inner ring (inner member) 6 having a hole 2 into which an axle is inserted, an outer ring (outer member) 8 arranged outside the inner ring 6, and arranged in a row between the inner ring 6 and the outer ring 8. , a plurality of balls 12 arranged in a row between the inner ring 6 and the outer ring 8, and a plurality of

retainers

14, 15 for holding the balls in fixed positions.

The inner ring 6 is fixed to a stationary axle. The outer ring 8 serves as a hub fixed to the wheel. Therefore, a hub flange 18 is formed on the outer ring 8 , and a wheel can be attached to the hub flange 18 with hub bolts 19 . Thus, the outer ring 8 is fixed to the wheel and rotates with the wheel. However, the outer ring 8 and the hub flange 18 may be formed as separate members and fixed together.

A common center axis Ax of the axle and hub bearing 1 extends vertically in FIG. In FIG. 1, only one portion with respect to the central axis Ax is shown. Although not shown in detail, the lower side of FIG. 1 is the outer side (outboard side) where the wheels of the automobile are arranged, and the upper side is the inner side (inboard side) where the differential gear and the like are arranged. The outer side and the inner side shown in FIG. 1 mean the radially outer side and the inner side, respectively.

A sealing device 20 for sealing the gap between the outer ring 8 and the inner ring 6 is arranged near the cylindrical end portion 8A of the outer ring 8 on the inboard side. The sealing device 20 prevents grease, that is, lubricant from flowing out from the inner space of the hub bearing 1, and foreign matter (including water (including muddy water or salt water) and dust) entering the hub bearing 1 from the outside. Prevent inflow. In FIG. 1, an arrow F indicates an example of the direction of foreign matter flow from the outside.

As shown in FIG. 2 , the sealing device 20 is arranged in the gap between the inboard-side end 8A of the outer ring 8 of the hub bearing 1 and the inner ring 6 of the hub bearing 1 . The sealing device 20 is annular, but only one portion relative to its central axis is shown in FIG. As can be seen from FIG. 2, the sealing device 20 has a composite structure comprising a first sealing member 30 and a second sealing member 40. As shown in FIG.

The first seal member 30 is a stationary seal member that is fixed to the stationary inner ring 6 and does not rotate. The first sealing member 30 has a rigid ring 31 made of a rigid material such as metal. Although not shown, the rigid ring 31 may be attached with an elastic ring made of an elastic material such as an elastomer.

The rigid ring 31 has a substantially L-shaped cross section. Specifically, the rigid ring 31 includes a cylindrical sleeve 31A and an annular flange 31B extending radially outward from the sleeve 31A. A sleeve 31A is attached to the inner ring 6 . Specifically, the end of the inner ring 6 is fitted into the sleeve 31A by an interference fit. Flange 31B is flat and lies in a plane perpendicular to the axis of sleeve 31A. The flange 31B is arranged on the inboard side of the sleeve 31A.

The second seal member 40 is a rotary seal member that is fixed to the rotating outer ring 8 and rotates. The second seal member 40 is a composite structure having a resilient ring 41 and a rigid ring 42 . The elastic ring 41 is made of an elastic material such as an elastomer. Rigid ring 42 is made of a rigid material, such as metal, and reinforces elastic ring 41 . Rigid ring 42 has a substantially L-shaped cross-sectional shape. A portion of the rigid ring 42 is embedded in the elastic ring 41 and is in close contact with the elastic ring 41 .

The second sealing member 40 has a tubular portion 44 , a disc portion 45 , a grease lip (radial lip) 46 , a seal lip (radial lip) 47 and side lips 48 .

The tubular portion 44 is attached to the outer ring 8. Specifically, the tubular portion 44 is fitted into the end portion 8A of the outer ring 8 by an interference fit. The tubular portion 44 is composed of an elastic ring 41 and a rigid ring 42 .

The disc portion 45 extends radially inward from the tubular portion 44 and faces the flange 31B of the rigid ring 31 of the first seal member 30 . The disk portion 45 is arranged on the outboard side of the tubular portion 44 . The disc portion 45 is also composed of the elastic ring 41 and the rigid ring 42 .

The grease lip 46 and the seal lip 47 are arranged radially inside the disk portion 45 and slidably contact the sleeve 31A. The grease lip 46 and the seal lip 47 are composed of the elastic ring 41 .

Between the outer ring 8 and the inner ring 6, grease is arranged in the space on the outboard side of the disc portion 45 (internal space of the hub bearing 1). This grease reduces the mutual friction between the

balls

10, 12, the outer ring 8 and the inner ring 6 (see FIG. 1).

The grease lip 46 is a thin plate in the shape of a truncated cone or a cylindrical cone extending obliquely from the elastic portion at the radially inner end of the disk portion 45 toward the radially inner side and the outboard side. The tip of the grease lip 46 contacts the outer peripheral surface of the sleeve 31A. The grease lip 46 prevents grease from flowing out from the internal space of the hub bearing 1 to the inboard side.

The seal lip 47 is a protrusion formed on the annular portion 49 extending from the elastic portion at the radially inner end of the disk portion 45 toward the inboard side. The annular portion 49 is also composed of the elastic ring 41 . In the initial state when the first sealing member 30 and the second sealing member 40 are not assembled, this ridge has a triangular cross-section shown in phantom lines. The seal lip 47 contacts the outer peripheral surface of the sleeve 31A and backs up the grease lip 46 . In other words, the grease that has passed through the grease lip 46 from the outboard side is prevented from flowing out to the inboard side.

A garter spring 50 is wound around the outer circumference of the annular portion 49 . The garter spring 50 exerts a radially inward compressive force on the seal lip 47 to increase the tightening force of the seal lip 47 against the sleeve 31A.

The side lip 48 is a thin plate extending from the elastic portion of the disc portion 45 toward the flange 31B. The side lip 48 is composed of the elastic ring 41 . The side lip 48 has a thick base portion 51 adjacent to the disk portion 45, and a thin tip portion 52 extending radially outward from the base portion 51 and obliquely toward the flange 31B and having a truncated cone shape or a conical tubular shape. . During low speed rotation of the outer ring 8 and the second seal member 40, the tip portion 52 of the side lip 48 slidably contacts the flange 31B.

The tubular portion 44 is arranged further outside the outer edge of the flange 31B of the first seal member 30 . An annular gap 54 is provided between the tubular portion 44 and the flange 31B of the first seal member 30 . Foreign matter may enter the space 55 between the flange 31B of the first seal member 30 and the disk portion 45 of the second seal member 40 through the gap 54 from the outside of the hub bearing 1 . Conversely, foreign matter can be discharged from the space 55 to the outside through the gap 54 .

When the outer ring 8 and the second seal member 40 rotate at a low speed (when the rotation speed is smaller than the threshold value), the side lip 48 contacts the flange 31B of the first seal member 30 and enters the space 55. It has the role of preventing foreign matter from further entering toward the seal lip 47 . The time of low speed rotation includes the time when the rotation of the outer ring 8 and the second seal member 40 is stopped. The threshold is, for example, the rotational speed (or number of revolutions), and the threshold may be a constant value or a variable value. For example, the threshold value may change (change over time) with the usage time of the sealing device 20, or may change according to the manner of use such as the ambient temperature of the sealing device 20. The side lip 48 may be coated with grease to reduce the torque imparted to the second seal member 40 from the flange 31B. This grease is different from the grease that typically lubricates the

balls

10, 12, outer ring 8 and inner ring 6.

On the other hand, when the outer ring 8 and the second seal member 40 rotate at high speed (when the rotational speed is greater than the threshold value), the side lip 48, particularly the tip portion 52, is applied to the side lip 48 itself, as shown in FIG. The centrifugal force deforms the first seal member 30 away from the flange 31B. Therefore, an annular gap 56 is provided between the tip portion 52 of the side lip 48 and the flange 31B. This is because centrifugal force is applied to the second seal member 40 fixed to the outer ring 8 in the sealing device 20 used in the outer ring rotating type hub bearing 1 . Thus, the dimensions of the side lip 48 are designed so that the tip 52 is separated from the flange 31B when a large centrifugal force is applied to the side lip 48 .

When the outer ring 8 and the second seal member 40 rotate at high speed, the side lip 48 separates from the flange 31B. A directed air current or centrifugal force is generated, and foreign matter that has entered the space 55 is discharged to the outside through the gap 54 . Also, foreign matter is discharged from the space 57 radially inside the side lip 48 through the gap 56 to the space 55 by airflow or centrifugal force, and is further discharged to the outside through the gap 54 .

As described above, the side lip 48 of the second seal member 40 attached to the rotating outer ring 8 slidably contacts the flange 31B when the rotational speed of the outer ring 8 is less than the threshold value, and the sealing device 20 sealing performance is ensured. That is, the side lip 48 prevents foreign matter that has entered the space 55 from further entering toward the seal lip 47 .

On the other hand, when the rotational speed of the outer ring 8 is higher than the threshold, the side lip 48 of the second seal member 40 deforms away from the flange 31B due to the centrifugal force acting on the side lip 48 itself. Therefore, the torque applied to the rotating outer ring 8 is small, and the wear of the side lip 48 and the increase in temperature due to frictional heat are suppressed.

FIG. 4 is a diagram illustrating another usage pattern of the sealing device 20 according to the first embodiment of the present invention. The sealing device 20 can also be used, for example, in an in-wheel motor unit as shown in FIG. An in-wheel motor unit is a driving device that is configured by integrating a hub bearing and a motor. , converts the power of the wheels into electric power through a motor generator to generate electricity.

For example, as shown in FIG. 4, the in-wheel motor unit 100 includes an inner ring rotating hub bearing 3, an outer casing 101 as an outer member attached to the hub bearing 3, an inner casing 102 as an inner member, and a motor generator. 103. Specifically, the outer casing 101 is a tubular member and forms an inner space for housing the hub bearing 3 . The outer casing 101 is sandwiched between a hub flange 18 provided on the inner ring 7 of the hub bearing 3 and a brake disc 110 attached to the hub flange 18 , and by fixing the wheel to the inner ring 7 with hub bolts 19 , the hub flange 18 and the brake disc 110 are attached. It is fixed between the brake disc 110 .

The inner casing 102 includes a tubular portion 102a, which is a tubular member forming an inner space for accommodating the outer ring 9 of the hub bearing 3, and a circular portion extending radially outward from the inboard-side end of the tubular portion 102a. It has a disk portion 102b which is a plate-like portion. The cylindrical portion 102a has a shape in which the outer ring 9 is fitted and fixed in the inner space.

As shown in FIG. 4, the outer casing 101 and the inner casing 102 are arranged such that the radially inner surface of the outer casing 101 and the radially outer surface of the cylindrical portion 102a of the inner casing 102 face each other. and the cylindrical portion 102a. As shown in FIG. 4, the outer casing 101 and the inner casing 102 have an inboard-side end (end 101a) of the outer casing 101 facing the disk portion 102b of the inner casing 102 in the central axis Ax direction. It has a shape that An annular gap is formed between the end portion 101a of the outer casing 101 and the disk portion 102b.

The motor generator 103 is a tubular member that extends along the central axis Ax, and is provided in an annular space between the outer casing 101 and the tubular portion 102a of the inner casing 102 . Specifically, the motor generator 103 includes a rotor 104 and a stator 105. The rotor 104 is fixed to the outer casing 101, and the stator 105 is fixed to the cylindrical portion 102a of the inner casing 102. .

In the in-wheel motor unit 100, the sealing device 20 prevents foreign matter from entering the in-wheel motor unit 100 through the annular gap between the end portion 101a of the outer casing 101 and the disk portion 102b of the inner casing 102. provided to prevent this. For example, as shown in FIG. 4 , the sealing device 20 is attached between the end portion 101 a of the outer casing 101 and the disk portion 102 b of the inner casing 102 . Specifically, the sleeve 31A of the first seal member 30 is fitted to the mounting surface 102c of the disc portion 102b of the inner casing 102 by an interference fit, so that the first seal member 30 is mounted on the inner casing 102. It is fixed to the plate portion 102b. Further, more specifically, the tubular portion 44 of the second seal member 40 is fitted to the mounting surface 101b of the end portion 101a of the outer casing 101 by an interference fit, so that the second seal member 40 is attached to the outer casing 101. is fixed to The mounting surface 102c of the disk portion 102b of the inner casing 102 is a cylindrical surface extending along the central axis Ax, and the mounting surface 101b of the end portion 101a of the outer casing 101 extends along the central axis Ax. It is an elongated cylindrical surface. Moreover, the mounting surface 101b and the mounting surface 102c face each other in the radial direction.

The sealing device 20 works in the in-wheel motor unit 100 in the same way as when it is attached to the hub bearing 1 described above (see FIG. 3). Specifically, the side lip 48 of the second seal member 40 attached to the rotating outer casing 101 is attached to the flange 31B when the rotation speed of the outer casing 101 and the second seal member 40 is lower than the threshold. The slidable contact ensures the sealing performance of the sealing device 20 . In other words, the side lip 48 prevents foreign matter from entering the space 55 from further entering toward the seal lip 47 . On the other hand, when the rotation speed of the outer casing 101 and the second seal member 40 is higher than the threshold, the side lip 48 of the second seal member 40 moves away from the flange 31B due to the centrifugal force acting on the side lip 48 itself. and a gap 56 is formed. Therefore, the torque applied to the rotating outer casing 101 is small, and the wear of the side lip 48 and temperature rise due to frictional heat are suppressed.

When the outer casing 101 and the second seal member 40 rotate at high speed, the side lip 48 separates from the flange 31B. An outward air current or centrifugal force is generated, and foreign matter that has entered the space 55 is discharged to the outside through the gap 54 . Also, foreign matter is discharged from the space 57 radially inside the side lip 48 through the gap 56 to the space 55 by airflow or centrifugal force, and is further discharged to the outside through the gap 54 .

Some in-wheel motor units are driven to rotate at high speed, and such in-wheel motor units are required to reduce torque based on sealing devices. According to the sealing device 20 according to the first embodiment of the present invention, as described above, the torque applied to the rotating outer casing 101 can be reduced when the outer casing 101 rotates at a high speed higher than the threshold. . In addition, when the outer casing 101 rotates at a high speed higher than the threshold value, it is possible to suppress wear of the side lip 48 and increase in temperature due to frictional heat, thereby suppressing performance degradation and shortening of the life of the sealing device 20. can. On the other hand, during this high-speed rotation, an air current directed radially outward or centrifugal force is generated, so that the intrusion of foreign matter can be suppressed. Thus, the sealing device 20 according to the first embodiment of the present invention can be suitably used also for in-wheel motors.

Next, a sealing device 21 according to a second embodiment of the invention will be described. A sealing device 21 according to the second embodiment of the present invention differs from the above-described sealing device 20 according to the first embodiment of the present invention in the configuration of the second sealing member. Further, the sealing device 21 according to the second embodiment of the present invention is used for an inner ring rotating type, and is different from the above-described sealing device 20 in terms of application. In the following, with regard to the configuration of the sealing device 21, the same reference numerals are given to the same configurations or configurations having the same functions as those of the sealing device 20, and the description thereof will be omitted, and the different configurations will be described.

As shown in FIG. 5, the annular sealing device 21 includes the first sealing member 30 of the sealing device 20 described above and a second sealing member 60 different from the second sealing member 40 of the sealing device 20. ing. The second seal member 60 has the rigid ring 42 of the second seal member 40 of the sealing device 20 described above. It has a different elastic ring 61 . 5, only one portion of the sealing device 21 with respect to the axis x is shown. In addition, in FIG. 5, the sealing device 21 is shown in a state (arrangement) in use, which will be described later.

The elastic ring 61 is made of an elastic material, such as an elastomer, like the elastic ring 41 of the second seal member 40 of the sealing device 20 . The elastic ring 61 is attached to the rigid ring 42 in the same manner as the elastic ring 41 . are embedded in the elastic ring 61 .

The elastic ring 61 of the second sealing member 60, as shown in FIG. However, unlike the elastic ring 41 of the second seal member 40 , it does not have a grease lip (radial lip) 46 and a seal lip (radial lip) 47 . Also, unlike the second seal member 40 , the second seal member 60 does not have the annular portion 49 and the garter spring 50 .

The side lip 62 has the same shape as the side lip 48 of the second seal member 40, and is part of the thin plate-like elastic ring 61 extending from the elastic portion of the disk portion 45 toward the flange 31B. The side lip 62 has an annular thick base portion 62a adjacent to the disk portion 45, and an annular thin distal end extending radially outward from the base portion 62a and obliquely toward the flange 31B and having a truncated cone shape or a conical cylindrical shape. and a portion 62b.

As shown in FIG. 5, the first sealing member 30 is arranged so as to cover the second sealing member 60 from the outside in the radial direction. Therefore, in use, the second seal member 60 is fixed radially inward of the first seal member 30 . The flange 31B of the first seal member 30 faces the outboard side, and the disk portion 45 of the second seal member 60 faces the inboard side.

In the usage state of the sealing device 21 described later, when the sealing device 21 is applied and the side lip 62 rotates at a low speed (when the rotation speed is smaller than the threshold value), the tip portion 62b of the side lip 62 slides on the flange 31B. Side lips 62 are designed to allow contact. On the other hand, when the sealing device 21 is applied and the side lip 62 rotates at high speed (when the rotation speed is greater than the threshold value), the side lip 62 deforms and the tip 62b of the side lip 62 moves away from the flange 31B. The side lip 62 is designed to move. However, the side lip 62 is designed so that the contact between the tip portion 62b of the side lip 62 and the flange 31B is maintained even when the sealing device 21 is applied and the side lip 62 rotates at high speed.

Also in the sealing device 21, an annular gap 54 is formed between the tubular portion 44 of the second sealing member 60 and the outer edge 31Bt of the flange 31B of the first sealing member 30, as shown in FIG. is provided. That is, in use, the outboard-side end portion 44a of the tubular portion 44 faces the outer edge 31Bt of the flange 31B with a space therebetween in the radial direction. A gap 54 is formed between it and the outer edge 31Bt. Gap 54 forms a labyrinth seal.

Further, as shown in FIG. 5, an annular gap 63 is provided between the disc portion 45 of the second seal member 60 and the sleeve 31A of the first seal member 30. As shown in FIG. In other words, when in use, the outer edge 45a of the disk portion 45 of the second seal member 60 is aligned with the inboard side portion (portion 31Ap) of the sleeve 31A of the first seal member 30. A gap 63 is formed between the outer edge 45a of the disk portion 45 and the portion 31Ap of the sleeve 31A. Gap 63 forms a labyrinth seal.

Next, the action of the sealing device 21 having the above configuration will be described. The sealing device 21 is attached to an application and is ready for use. The application target of the sealing device 21 is, for example, a hub bearing, and the hub bearing to which the sealing device 21 is applied is an inner ring rotation type hub bearing. FIG. 6 is a cross-sectional view of the hub bearing 4 to which the sealing device 21 is attached and to which the sealing device 21 is applied.

As shown in FIG. 6, the hub bearing 4 has an inner ring 120 and an outer ring 130. Between the inner ring 120 and the outer ring 130 are a plurality of balls 10 arranged in a row and a plurality of balls 10 arranged in a row. A plurality of balls 12 are provided and a plurality of

retainers

14, 15 for holding the balls in place. The inner ring 120 and the outer ring 130 are provided with the

balls

10 and 12, which are rolling elements, so that the inner ring 120 and the outer ring 130 are rotatable relative to each other on the same axis indicated by the center axis Ax. Specifically, when the hub bearing 4 attached to a vehicle or the like is used, the outer ring 130 is fixed to, for example, a suspension system of the vehicle, and the inner ring 120 is rotatable relative to the outer ring 130 . Specifically, the inner ring 120 has an inner ring 121 and a hub ring 122. The hub ring 122 has a cylindrical shaft portion 123 extending along the center axis Ax and a hub flange 124. ing. The hub flange 124 is a portion extending radially outward from one end of the shaft portion 123 on the outboard side in a disc shape, and is a portion to which wheels (not shown) are attached by a plurality of hub bolts 19 . The inner ring 121 is fitted to the inboard end of the shaft portion 123 of the inner ring 120 to hold the

balls

10 and 12 in the space between the inner ring 120 and the outer ring 130 .

Outer ring 130 has a through hole 131 extending in the direction of central axis Ax. An annular space extending along the central axis Ax is formed between the shaft portion 123 and the through hole 131 . In this space, the

balls

10, 12 are accommodated and held by the

cages

14, 15 as described above, and a lubricant is applied or injected. A sealing device 21 is attached to an inboard side opening 126 of the hub bearing 4 in which the space between the inner ring 121 and the shaft portion 123 and the through hole 131 forms an opening opened on the inboard side. Another sealing device 140 is attached to an outboard-side opening 127 of the hub bearing 4 in which the space between 121 and the shaft portion 123 and the through hole 131 forms an opening opened on the outboard side. The internal space of the hub bearing 4 is sealed by the sealing

devices

21 and 140 to prevent the lubricant in the internal space from leaking to the outside and prevent foreign matter from entering the internal space from the outside. are being prevented. The sealing device 140 is a conventionally known sealing device, and detailed description thereof will be omitted. Note that the sealing device 21 can also be applied as the sealing device 140 . The configuration of the hub bearing to which the sealing device 21 is applied is not limited to the configuration of the hub bearing 4 described above.

Specifically, the sleeve 31A of the first sealing member 30 of the sealing device 21 is attached to the cylindrical end portion 130A on the inboard side of the outer ring 130, and the inboard side of the inner ring 121 of the inner ring 120 is attached. The tubular portion 44 of the second sealing member 60 of the sealing device 21 is attached to the cylindrical end portion 121A, and the sealing device 21 is attached to the hub bearing 4 (see FIG. 5). Specifically, the sleeve 31A of the first sealing member 30 is fitted into the end portion 130A of the outer ring 130 in an interference fit, and the tubular portion 44 of the second sealing member 60 is specifically fitted to the inner ring. The end portion 121A of 121 is fitted by an interference fit method. The axis x of the sealing device 21 attached to the hub bearing 4 coincides or substantially coincides with the central axis Ax of the hub bearing 4 .

The sealing device 21 is fixed to the hub bearing 4 as described above. The first seal member 30 is a stationary seal member that is fixed to the stationary outer ring 130 and does not rotate. On the other hand, the second seal member 60 is a rotary seal member that is fixed to the rotating inner ring 120 and rotates. The sealing device 21 in the hub bearing 4 behaves differently depending on the rotational speed of the inner ring 120 .

Specifically, when the inner ring 120 and the second seal member 60 rotate at a low speed (when the rotation speed is smaller than the threshold value), the side lip 62 is located on the flange of the first seal member 30 as shown in FIG. 31B and has a role of preventing foreign matter from entering the space 55 from further entering the inner space of the hub bearing 4. As shown in FIG. The time of low speed rotation includes the time when the rotation of the inner ring 120 and the second seal member 60 is stopped. The side lip 62 may be coated with grease to reduce torque applied to the second seal member 60 from the flange 31B. This grease is different from the grease that typically lubricates the

balls

10, 12, inner ring 120, and outer ring 130.

On the other hand, when the inner ring 120 and the second seal member 60 rotate at a high speed (when the rotation speed is greater than the threshold value), the side lip 62, particularly the tip portion 62b, moves toward the side lip 62 itself, as indicated by the dotted line in FIG. is deformed away from the flange 31B of the first seal member 30 by the centrifugal force applied to the first seal member 30. As shown in FIG. However, the side lip 62 is designed so that it will not completely separate from the flange 31B due to the centrifugal force applied during high-speed rotation. Therefore, unlike the sealing device 20, an annular gap is not provided between the tip portion 62b of the side lip 62 and the flange 31B when the inner ring 120 and the second seal member 60 rotate at high speed. Due to the centrifugal force applied to the side lip 62, the interference between the tip 62b and the flange 31B or the reaction force of the side lip 62 is reduced. Thereby, when the inner ring 120 rotates at high speed, the sliding resistance between the side lip 62 and the flange 31B can be reduced, and the torque applied to the rotating inner ring 120 can be reduced. Also, it is possible to suppress the wear of the side lip 62 and the increase in temperature due to frictional heat.

5, an annular gap 54 is formed between the end portion 44a of the tubular portion 44 of the second seal member 60 and the outer edge 31Bt of the flange 31B of the first seal member 30. provided, the gap 54 functions as a labyrinth seal. Therefore, foreign matter is prevented from entering the internal space of the hub bearing 4 .

On the other hand, the labyrinth seal formed by the gap 54 prevents the lubricant from flowing out of the inner space of the hub bearing 4 , and the side lip 62 prevents the lubricant from flowing out of the hub bearing 4 . is prevented. In this manner, the sealing device 21 can prevent lubricant from flowing out of the internal space of the hub bearing 4 by the gap 54 and the side lip 62 regardless of the rotational speed of the inner ring 120 .

As shown in FIG. 5, an annular gap 63 is formed between the outer edge 45a of the disk portion 45 of the second seal member 60 and the portion Ap of the sleeve 31A of the first seal member 30. provided, the gap 63 functions as a labyrinth seal. Therefore, foreign matter is prevented from entering the space 55 inside the sealing device 21 from the outside of the hub bearing 4 . In this manner, the sealing device 21 can prevent foreign matter from entering the internal space of the hub bearing 4 by the gap 63 as well. Also, the gap 63 can prevent the lubricant from flowing out of the hub bearing 4 .

As described above, the side lip 62 of the second seal member 60 attached to the rotating inner ring 120 slidably contacts the flange 31B when the rotational speed of the inner ring 120 is less than the threshold value, thereby closing the sealing device. 21 sealing performance is ensured. That is, during low-speed rotation, the side lip 62 prevents foreign matter from entering the space 55 and further entering the inner space of the hub bearing 4 .

On the other hand, when the rotational speed of the inner ring 120 is higher than the threshold, the side lip 62 of the second seal member 60 is rotated by the centrifugal force exerted on the side lip 62 itself to the extent that contact with the flange 31B is maintained. transform away from Therefore, during high-speed rotation, the sealing device 21 reduces the torque applied to the rotating inner ring 120 while ensuring sealing performance, and suppresses temperature rise due to wear of the side lip 62 and frictional heat.

Next, a sealing device 22 according to a third embodiment of the invention will be described. A sealing device 22 according to the third embodiment of the present invention differs from the above-described sealing device 20 according to the first embodiment of the present invention in the configurations of the first sealing member and the second sealing member. Further, the sealing device 22 according to the third embodiment of the present invention is used for an inner ring rotation type application object like the sealing device 21 according to the second embodiment of the present invention. It differs from the sealing device 20 . Hereinafter, with respect to the configuration of the sealing device 22, the same reference numerals are given to the same configurations or configurations having the same functions as those of the sealing device 20, and the description thereof will be omitted, and the different configurations will be described.

As shown in FIG. 7, the annular sealing device 22 has a first sealing member 70 different from the first sealing member 30 of the sealing device 20 described above and a second sealing member 40 of the sealing device 20. and a second sealing member 65 . The first seal member 70 has the rigid ring 42 of the second seal member 30 of the sealing device 20 described above and the elastic ring 71 . Also, the second seal member 65 has the rigid ring 31 of the first seal member 30 of the sealing device 20 described above and the elastic ring 66 . 7, only one portion of the sealing device 22 with respect to the axis x is shown. In addition, in FIG. 7, the sealing device 22 is shown in a state (arrangement) in use, which will be described later.

As shown in FIG. 7, the first sealing member 70 is arranged so as to cover the second sealing member 65 from the outside in the radial direction. Therefore, in use, the second seal member 65 is fixed radially inward of the first seal member 70 . The flange 31B of the second seal member 65 faces the inboard side, and the disk portion 45 of the first seal member 70 faces the outboard side.

The elastic ring 71 of the first seal member 70 is made of an elastic material such as an elastomer. The elastic ring 71 is attached to the rigid ring 42 . Specifically, the elastic ring 71 is in close contact with part of the rigid ring 42 , and part of the rigid ring 42 is attached to the elastic ring 71 . Buried. As shown in FIG. 7, the elastic ring 71 consists of the tubular portion 44 of the elastic ring 41 of the second seal member 40 of the sealing device 20 and the disk portion 45 of the elastic ring 41 of the second seal member 40. It has an inner end portion 72 which is part of the radially inner end, a grease lip 46 and a sealing lip 47 . The elastic ring 71 also has an annular portion 49 of the second seal member 40 extending from the inner end 72 . Also, the first seal member 70 has a garter spring 50 like the second seal member 40 .

Like the grease lip 46 and the seal lip 47 of the second seal member 40 of the sealing device 20, the grease lip 46 and the seal lip 47 are arranged radially inside the disk portion 45 and slide on the sleeve 31A. configured for movably contact. Specifically, the grease lip 46 extends from the inner end 72 and the sealing lip 47 is formed on an annular portion 49 extending from the inner end 72 .

As shown in FIG. 7, the elastic ring 71 of the first seal member 70 is not formed in the portion of the disk portion 45 of the first seal member 70 radially outside the inner end portion 72 . Therefore, in the disk portion 45 of the first seal member 70 , a portion radially outside the inner end portion 72 of the rigid ring 42 is exposed, and the rigid ring 42 is radially larger than the inner end portion 72 . A contact surface 73 that is an annular surface facing the inboard side is provided on the portion of the disk portion 45 on the direction outer side.

The elastic ring 66 of the second seal member 65 is made of an elastic material such as elastomer. The elastic ring 66 is attached to the rigid ring 31, as shown in FIG. The part is embedded in the elastic ring 66 .

The elastic ring 66 of the second seal member 65 is, as shown in FIG. It has a side lip 68 and a labyrinth lip 69 . The base portion 67 extends annularly around the axis x and is formed so as to cover the radially outer end portion of the flange 31B on the radially outer side.

As shown in FIG. 7, the side lip 68 extends from the surface (surface 67a) facing the outboard side of the base portion 67 of the elastic ring 66, and has the same shape as the side lip 48 of the sealing device 20 described above. and is the portion of the thin plate-like elastic ring 66 that extends toward the contact surface 73 of the rigid ring 42 of the first seal member 70 . For example, as shown in FIG. 7, the side lip 68 has an annular thick base portion 68a adjacent to the base portion 67, and a truncated cone shape or a conical tubular shape extending radially outward from the base portion 68a and obliquely toward the contact surface 73. and an annular thin tip 68b having a shape.

When the sealing device 22 is used, which will be described later, when the sealing device 22 is applied and the second sealing member 65 rotates at a low speed (when the rotation speed is smaller than the threshold value), the tip 68b of the side lip 68 moves toward the rigid ring. The side lip 68 is designed to slidably contact the contact surface 73 of 42 . On the other hand, when the sealing device 22 is applied and the second sealing member 65 rotates at high speed (when the rotation speed is greater than the threshold value), the tip portion of the side lip 68 is Side lip 68 is designed such that 68b deforms away from contact surface 73 of rigid ring 42 . When the sealing device 22 is applied and the second seal member 65 rotates at high speed, the side lip 68 moves away from the contact surface 73 of the rigid ring 42 as long as the tip 68b does not move away from the contact surface 73 of the rigid ring 42. It may be designed to

Further, as shown in FIG. 7, the outer end portion 67b, which is the portion of the base portion 67 that covers the radially outer end portion of the flange 31B of the second seal member 65, is located inside the tubular portion 44 of the first seal member 70. It faces a labyrinth receiving portion 71a, which is a portion of the elastic ring 71 at the end on the board side, with a gap in the radial direction. Therefore, a gap 74 is formed between the outer end portion 67 b of the base portion 67 and the labyrinth receiving portion 71 a of the tubular portion 44 .

As shown in FIG. 7, the labyrinth lip 69 extends from the outer end 67b of the base portion 67 toward the labyrinth receiving portion 71a. They are facing each other with a space between them. Thus, in the gap 74, an annular gap 74a is formed between the tip 69a of the labyrinth lip 69 and the labyrinth receiving portion 71a to further narrow the gap 74. As shown in FIG. Gap 74 and gap 74a form a labyrinth seal.

Next, the action of the sealing device 22 having the above configuration will be described. The sealing device 22 is attached to an application and ready for use. The application target of the sealing device 22 is, for example, a hub bearing, and the hub bearing to which the sealing device 22 is applied is an inner ring rotation type hub bearing. The sealing device 22 is attached, for example, to the hub bearing 4 to which the sealing device 21 described above is attached (see FIG. 6). The illustration of the hub bearing 4 to which the sealing device 22 is attached is omitted.

The sealing device 22 is attached to the inboard side opening 126 of the hub bearing 4 in the same manner as the sealing device 21 . Specifically, the tubular portion 44 of the first sealing member 70 of the sealing device 22 is attached to the inboard side end portion 130A of the outer ring 130, and the inboard side end portion of the inner ring 121 of the inner ring 120 is attached. The sleeve 31A of the second sealing member 65 of the sealing device 22 is attached to 121A, and the sealing device 22 is attached to the hub bearing 4 (see FIGS. 6 and 7). The tubular portion 44 of the first sealing member 70 is specifically fitted to the end portion 130A of the outer ring 130 in an interference fit, and the sleeve 31A of the second sealing member 65 is specifically fitted to the inner ring. The end portion 121A of 121 is fitted by an interference fit method. The axis x of the sealing device 22 attached to the hub bearing 4 coincides or substantially coincides with the central axis Ax of the hub bearing 4 .

The sealing device 22 is fixed to the hub bearing 4 as described above. The first seal member 70 is fixed to the stationary outer ring 130 and is a stationary seal member that does not rotate. On the other hand, the second seal member 65 is a rotary seal member that is fixed to the rotating inner ring 120 and rotates. The sealing device 22 in the hub bearing 4 acts differently depending on the rotational speed of the inner ring 120 .

Specifically, when the inner ring 120 and the second seal member 65 rotate at low speed (when the rotation speed is smaller than the threshold value), the side lip 68 reduces the rigidity of the first seal member 70 as shown in FIG. It contacts the contact surface 73 of the ring 42 and has a role of preventing foreign matter from entering the space 55 from further entering the inner space of the hub bearing 4 . The time of low speed rotation includes the time when the rotation of the inner ring 120 and the second seal member 65 is stopped. The side lip 68 may be coated with grease to reduce the torque imparted to the second seal member 65 from the contact surface 73 of the rigid ring 42 . This grease is different from the grease that typically lubricates the

balls

10, 12, inner ring 120, and outer ring 130.

On the other hand, when the inner ring 120 and the second seal member 65 rotate at a high speed (when the rotational speed is greater than the threshold value), the side lip 68, particularly the tip portion 68a, moves toward the side lip 68 itself, as indicated by the dotted line in FIG. is deformed away from the contact surface 73 of the rigid ring 42 of the first seal member 70 by the centrifugal force applied to the first seal member 70 . Therefore, similarly to the sealing device 20, when the inner ring 120 and the second seal member 65 rotate at high speed, an annular gap 56 is provided between the tip portion 68a of the side lip 68 and the contact surface 73 of the rigid ring 42. be done. As a result, sliding resistance between the side lip 68 and the contact surface 73 of the rigid ring 42 can be eliminated when the inner ring 120 rotates at high speed, and the torque applied to the rotating inner ring 120 can be reduced. Also, it is possible to suppress the wear of the side lip 68 and the increase in temperature due to frictional heat.

7,

annular gaps

74 and 74a are provided between the labyrinth lip 69 of the second seal member 65 and the labyrinth receiving portion 71a of the tubular portion 44 of the first seal member 70. The

gaps

74, 74a function as labyrinth seals. Therefore, foreign matter is prevented from entering the space 55 inside the sealing device 22 from the outside of the hub bearing 4 . In this manner, the sealing device 22 can prevent foreign matter from entering the internal space of the hub bearing 4 by the

gaps

74 and 74a. In addition, it is possible to prevent the lubricant from flowing out of the hub bearing 4 .

Also, the grease lip 46 and the seal lip 47 act similarly to the grease lip 46 and the seal lip 47 of the sealing device 20 described above, respectively. That is, the grease lip 46 prevents the lubricant from flowing out from the inner space of the hub bearing 4 to the inboard side. In addition, the seal lip 47 backs up the grease lip 46 and prevents the lubricant that has passed through the grease lip 46 from flowing out from the outboard side to the inboard side.

The grease lip 46 has a shape capable of exhibiting a sufficient clamping force (bonding force) to the sleeve 31A so that the grease lip 46 does not separate from the sleeve 31A when the inner ring 120 of the hub bearing 4 rotates. is preferably formed. This prevents the tip of the grease lip 46 from separating from the sleeve 31A during rotation of the inner ring 120 of the hub bearing 4, particularly during high-speed rotation, and prevents lubricant from leaking from the inner space of the hub bearing 4 to the inboard side. can be suppressed.

On the other hand, the garter spring 50 increases the tightening force (tightening force) of the seal lip 47 to the sleeve 31A. It is possible to suppress the leakage of the lubricant to the inboard side.

As described above, the side lip 68 of the second seal member 65 attached to the rotating inner ring 120 is slidable on the contact surface 73 of the rigid ring 42 when the rotational speed of the inner ring 120 is lower than the threshold. contact to ensure the sealing performance of the sealing device 22 . That is, during low-speed rotation, the side lip 68 prevents foreign matter from entering the space 55 and further entering the inner space of the hub bearing 4 .

On the other hand, when the rotational speed of the inner ring 120 is higher than the threshold, the side lip 68 of the second seal member 65 is deformed away from the contact surface 73 of the rigid ring 42 by the centrifugal force acting on the side lip 68 itself. . Therefore, during high-speed rotation, the sealing device 22 reduces the torque applied to the rotating inner ring 120, and also suppresses wear of the side lip 68 and temperature rise due to frictional heat.

When the inner ring 120 rotates at a high speed, the side lip 68 separates from the contact surface 73 of the rigid ring 42, but since the second seal member 65 itself rotates at a high speed, the space 55 is radially outward. A directed air current or centrifugal force is generated, and foreign matter that has entered the space 55 is discharged to the outside through the

gaps

74 and 74a. As shown in FIG. 7, if the labyrinth lip 69 extends diagonally outward in the radial direction and toward the inboard side, foreign matter that has entered as described above can be easily discharged to the outside through the

gaps

74 and 74a. can. Foreign matter is discharged from the space 57 inside the side lip 68 in the radial direction by the airflow or centrifugal force through the gap 56 between the side lip 68 and the contact surface 73 to the space 55, and then to the outside through the

gaps

74 and 74a. Ejected.

Next, a sealing device 23 according to a fourth embodiment of the invention will be described. A sealing device 23 according to the fourth embodiment of the present invention differs from the above-described sealing device 22 according to the third embodiment of the present invention in the configurations of the first sealing member and the second sealing member. Hereinafter, with respect to the configuration of the sealing device 23, the same reference numerals are given to the same configurations or configurations having the same functions as those of the sealing device 22, and the description thereof will be omitted, and the different configurations will be described.

As shown in FIG. 8, the annular sealing device 23 has a first sealing member 75 different from the first sealing member 70 of the sealing device 22 described above and a second sealing member 65 of the sealing device 22. and a second sealing member 80 . The first seal member 75 has the rigid ring 42 of the first seal member 70 of the sealing device 22 described above and an elastic ring 76 different from the elastic ring 71 of the first seal member 70 . The second seal member 80 includes a rigid ring 81 different from the rigid ring 31 of the second seal member 65 of the sealing device 22 described above and an elastic ring 82 different from the elastic ring 66 of the second seal member 65 . and 8, only one portion of the sealing device 23 with respect to the axis x is shown. In addition, in FIG. 8, the sealing device 23 is shown in a state (arrangement) in use, which will be described later.

As shown in FIG. 8, the first sealing member 75 is arranged so as to cover the second sealing member 80 from the outside in the radial direction. Therefore, in use, the second seal member 80 is fixed radially inward of the first seal member 75 . Further, a later-described flange 81B of the second seal member 80 faces the inboard side, and the disk portion 45 of the first seal member 75 faces the outboard side.

The elastic ring 76 of the first seal member 75 comprises, as shown in FIG. It differs from the elastic ring 71 of the first sealing member 70 of the sealing device 22 in that it does not have a Therefore, the first seal member 75 does not have the garter spring 50 .

The rigid ring 81 of the second sealing member 80 is made of a rigid material, such as metal, and corresponds to the sleeve 31A of the rigid ring 31 of the second sealing member 65 of the sealing device 22, as shown in FIG. It has a sleeve 81A which is a portion and a flange 81B which is a portion corresponding to the flange 31B of the rigid ring 31. The rigid ring 81 has a shape similar to that of the rigid ring 42, and the sleeve 81A has a shape similar to that of the tubular portion 44 of the rigid ring 42, as shown in FIG. 81B has the same shape as the disk portion 45 of the rigid ring 42 .

The elastic ring 82 of the second seal member 80 is made of an elastic material such as elastomer. The elastic ring 82 is attached to the rigid ring 81, as shown in FIG. The portion is embedded in the elastic ring 82 .

As shown in FIG. 8, the elastic ring 82 of the second seal member 80 is attached to the outboard side surface of the flange 81B of the rigid ring 81 and the radially outer surface of the sleeve 81A of the rigid ring 81. It has a base 83 which is a portion, and side lips 68 and labyrinth lip 69 which are portions extending from the base 83 . The elastic ring 82 also has a seal projection 84 extending from the base portion 83, as shown in FIG.

The base portion 83 extends annularly around the axis x, and is formed so as to cover the radially outer end portion of the flange 81B on the radially outer side, and on the outboard side of the sleeve 81A. is formed to cover the end of the

The side lip 68 extends from the surface (surface 83a) facing the outboard side of the base portion 83 of the elastic ring 82, as shown in FIG. It is a portion of a thin plate-like elastic ring 82 that has the same shape as 68 and extends toward the contact surface 73 of the rigid ring 42 of the first sealing member 75 . For example, as shown in FIG. 8, the side lip 68 has an annular thick base portion 68a adjacent to the base portion 83 and a truncated cone shape or a conical tubular shape extending radially outward from the base portion 68a and obliquely toward the contact surface 73. and an annular thin tip 68b having a shape.

In the state of use of the sealing device 23, which will be described later, when the object to which the sealing device 23 is applied and the second sealing member 80 rotates at a low speed (when the rotation speed is smaller than the threshold value), the tip portion 68b of the side lip 68 is moved to the rigid ring. The side lip 68 is designed to slidably contact the contact surface 73 of 42 . On the other hand, when the sealing device 23 is applied and the second sealing member 80 rotates at high speed (when the rotation speed is greater than the threshold value), the tip portion of the side lip 68 is Side lip 68 is designed such that 68b deforms away from contact surface 73 of rigid ring 42 . When the sealing device 23 is applied and the second sealing member 80 rotates at high speed, the side lip 68 moves away from the contact surface 73 of the rigid ring 42 within a range in which the tip portion 68b does not move away from the contact surface 73. It may be designed to

Further, as shown in FIG. 8, the outer end portion 83b, which is the portion of the base portion 83 that covers the radially outer end portion of the flange 81B of the second seal member 80, is the elastic portion of the tubular portion 44 of the first seal member 75. It faces the labyrinth receiving portion 71a of the ring 76 with a gap in the radial direction. Therefore, a gap 74 is formed between the outer end portion 83 b of the base portion 83 and the labyrinth receiving portion 71 a of the tubular portion 44 .

As shown in FIG. 8, the labyrinth lip 69 extends from the outer end 83b of the base 83 toward the labyrinth receiving portion 71a. They are facing each other with a space between them. Thus, in the gap 74, an annular gap 74a is formed between the tip 69a of the labyrinth lip 69 and the labyrinth receiving portion 71a to further narrow the gap 74. As shown in FIG. Gap 74 and gap 74a form a labyrinth seal.

The seal projection 84 is a ring-shaped portion around the axis x, and as shown in FIG. be. The seal projection 84 extends from the outboard side end portion 83 c toward the inner edge 45 b that is the radially inner edge of the disk portion 45 of the rigid ring 42 of the first seal member 75 . As shown in FIG. 8, the inner edge 45b of the rigid ring 42 is positioned, for example, radially outward and on the outboard side with respect to the outboard side end portion 83c of the base portion 83. extends obliquely from the outboard side end 83c radially outward and toward the outboard side. Further, the sealing projection 84 is formed in such a shape that the tip portion (tip portion 84 a ) of the sealing projection 84 contacts the inner edge 45 b of the rigid ring 42 .

Next, the action of the sealing device 23 having the above configuration will be described. The sealing device 23 is attached to the application and is ready for use. The application target of the sealing device 23 is, for example, a hub bearing, and the hub bearing to which the sealing device 23 is applied is an inner ring rotation type hub bearing. The sealing device 23 is mounted, for example, like the sealing device 22, on the hub bearing 4 to which the sealing device 21 described above is mounted (see FIG. 6). The illustration of the hub bearing 4 to which the sealing device 23 is attached is omitted.

The sealing device 23 is attached to the inboard side opening 126 of the hub bearing 4 in the same manner as the sealing device 22 . Specifically, the tubular portion 44 of the first sealing member 75 of the sealing device 23 is attached to the inboard side end portion 130A of the outer ring 130, and the inboard side end portion of the inner ring 121 of the inner ring 120 is attached. The sleeve 81A of the second seal member 80 of the sealing device 23 is attached to 121A, and the sealing device 23 is attached to the hub bearing 4 (see FIGS. 6 and 8). The tubular portion 44 of the first sealing member 75 is specifically fitted to the end portion 130A of the outer ring 130 in an interference fit, and the sleeve 81A of the second sealing member 80 is specifically fitted to the inner ring. The end portion 121A of 121 is fitted by an interference fit method. The axis x of the sealing device 23 attached to the hub bearing 4 coincides or substantially coincides with the central axis Ax of the hub bearing 4 .

The sealing device 23 is fixed to the hub bearing 4 as described above. The first seal member 75 is a stationary seal member that is fixed to the stationary outer ring 130 and does not rotate. On the other hand, the second seal member 80 is a rotary seal member that is fixed to the rotating inner ring 120 and rotates. The sealing device 23 in the hub bearing 4 acts differently depending on the rotational speed of the inner ring 120 .

Specifically, when the inner ring 120 and the second seal member 80 rotate at a low speed (when the rotation speed is smaller than the threshold value), the side lip 68 of the sealing device 22 and the side lip 68 of the sealing device 22 as shown in FIG. It works similarly to contact the contact surface 73 of the rigid ring 42 of the first seal member 75 to prevent foreign matter from entering the space 55 from further entering the inner space of the hub bearing 4 . It has a deterrent role. The time of low speed rotation includes the time when the rotation of the inner ring 120 and the second seal member 80 is stopped. The side lip 68 may be coated with grease to reduce the torque imparted to the second seal member 80 from the contact surface 73 of the rigid ring 42 . This grease is different from the grease that typically lubricates the

balls

10, 12, inner ring 120, and outer ring 130.

On the other hand, when the inner ring 120 and the second seal member 80 rotate at high speed (when the rotation speed is greater than the threshold value), the side lip 68, particularly the tip portion 68b, of the sealing device 22, as indicated by the dotted line in FIG. Acting like the side lip 68 , the centrifugal force on the side lip 68 itself deforms it away from the contact surface 73 of the rigid ring 42 of the first sealing member 75 . Therefore, similarly to the sealing device 22, when the inner ring 120 and the second sealing member 80 rotate at high speed, the annular gap 56 is formed between the tip portion 68b of the side lip 68 and the contact surface 73 of the rigid ring 42. be provided. As a result, sliding resistance between the side lip 68 and the contact surface 73 can be eliminated when the inner ring 120 rotates at high speed, and the torque applied to the rotating inner ring 120 can be reduced. Also, it is possible to suppress the wear of the side lip 68 and the increase in temperature due to frictional heat.

8,

annular gaps

74 and 74a are provided between the labyrinth lip 69 of the second seal member 80 and the labyrinth receiving portion 71a of the tubular portion 44 of the first seal member 75. and, like the

gaps

74, 74a of the sealing device 22, the

gaps

74, 74a function as labyrinth seals. Therefore, foreign matter is prevented from entering the space 55 inside the sealing device 23 from the outside of the hub bearing 4 . In this manner, the sealing device 23 can prevent foreign matter from entering the inner space of the hub bearing 4 by the

gaps

Further, the tip portion 84a of the seal projection 84 is in contact with the inner edge 45b of the rigid ring 42 of the first seal member 75, and the seal projection 84 contacts the inner end of the rigid ring 42 of the first seal member 75. It closes the annular gap between the edge 45b and the outboard side end 83c of the elastic ring 82 of the second seal member 80 . Therefore, the seal projection 84 prevents the lubricant from flowing out from the inner space of the hub bearing 4 to the inboard side. Also, the seal projection 84 prevents foreign matter from entering the internal space of the hub bearing 4 .

The tip 84a of the seal projection 84 is in contact with the inner edge 45b of the rigid ring 42 from the inside in the radial direction. Therefore, when the inner ring 120 of the hub bearing 4 rotates and a centrifugal force is applied to the seal projection 84 , the distal end portion 84 a of the seal projection 84 is further pressed against the inner edge 45 b of the rigid ring 42 . Therefore, when the inner ring 120 of the hub bearing 4 rotates, particularly during high-speed rotation, it is possible to prevent the tip 84a of the seal projection 84 from separating from the inner edge 45b of the rigid ring 42. The leakage of the lubricant to the side can be further suppressed.

As described above, the side lip 68 of the second seal member 80 attached to the rotating inner ring 120 is slidable on the contact surface 73 of the rigid ring 42 when the rotational speed of the inner ring 120 is less than the threshold. to ensure the sealing performance of the sealing device 23. That is, during low-speed rotation, the side lip 68 prevents foreign matter from entering the space 55 and further entering the inner space of the hub bearing 4 .

On the other hand, when the rotational speed of the inner ring 120 is higher than the threshold value, the side lip 68 of the second seal member 80 is deformed away from the contact surface 73 of the rigid ring 42 by the centrifugal force acting on the side lip 68 itself. . Therefore, during high-speed rotation, the sealing device 23 reduces the torque applied to the rotating inner ring 120, and suppresses temperature rise due to wear of the side lip 68 and frictional heat.

When the inner ring 120 rotates at a high speed, the side lip 68 separates from the contact surface 73 of the rigid ring 42. However, since the second seal member 80 itself rotates at a high speed, the inside of the space 55 is radially outward. A directed air current or centrifugal force is generated, and foreign matter that has entered the space 55 is discharged to the outside through the

gaps

74 and 74a. As shown in FIG. 8, if the labyrinth lip 69 extends diagonally outward in the radial direction and toward the inboard side, foreign matter that has entered as described above can be easily discharged to the outside through the

gaps

74 and 74a. Ejected.

Note that the rotational speed thresholds of the

hub bearings

1, 3, 4 at which the

side lips

48, 62, 68 are deformed at high speeds are, for example, It can be adjusted by the shape of 52, 62b, 68b, the characteristics of the elastic material of the

elastic rings

41, 61, 66, 82, and the like. The shapes of the

base portions

51, 62a, 68a and the

tip portions

52, 62b, 68b include, for example, the thickness and hardness of the

base portions

51, 62a, 68a and the

tip portions

52, 62b, 68b. Properties of the elastic material include, for example, the elastic modulus of the elastic material. Further, the threshold values of the rotational speeds of the

hub bearings

1, 3, 4 at which the

side lips

48, 62, 68 are respectively deformed during high-speed rotation are the

first seal members

30, 70, 75 and the second It can also be adjusted by the distance (interval) to the

seal members

40 , 60 , 65 , 80 .

Although the invention has been illustrated and described with reference to preferred embodiments thereof, it will be appreciated by those skilled in the art that changes in form and detail can be made without departing from the scope of the invention as set forth in the claims. One thing will be understood. Such changes, alterations and modifications are intended to fall within the scope of the present invention.

For example, multiple side lips may be provided.

A protrusion may be provided in the space 55 to reduce the entry of foreign matter into the

side lips

48, 62, 68. The protrusions may be formed on the

first sealing members

30, 70, 75 or may be formed on the

second sealing members

40, 60, 65.

1, 3, 4... Hub bearing 2...

Hole

6, 120... Inner ring (inner member) 8, 130... Outer ring (outer member) 20, 21, 22, 23...

Sealing device

30, 70, 75... First sealing

member

31, 81...

rigid ring

31A, 81A... sleeve 31Ap...

portion

31B, 81B... flange 31Bt...

outer edge

40, 60, 65, 80... second sealing

member

41 , 61, 66, 82... Elastic ring 42... Rigid ring 44... Tubular part 44a... End part 45... Disk part 45a... Outer edge 45b... Inner edge 46... Grease lip (radial lip ), 47... Seal lip (radial lip), 48, 62, 68... Side lip, 49... Annular part, 50... Garter spring, 51, 62a, 68a... Base part, 52, 62b, 68b... Tip part, 54, 63, 74, 74a...

Gap

67, 83...

Base part

67a, 83a...

Surface

67b, 83b... Outer end part 69... Labyrinth lip 69a...

Tip part

71, 76... Elastic ring 71a... Labyrinth receiving part , 72... Inner end 73... Contact surface 83c... Outboard side end 84... Seal projection 84a... Tip part 100... In-wheel motor unit 101... Outer casing 101a... End 101b... Mounting Surface 102... Inner casing 102a... Cylindrical part 102b... Disk part 102c... Mounting surface 103... Motor generator 104... Rotor 105... Stator 110... Brake disc 121... Inner ring 121A... End , 122...Hub ring, 123...Axle, 124...Hub flange, 126...Inboard side opening, 127...Outboard side opening, 130A...End, 131...Through hole, 140...Other sealing device, Ax ... central axis, x ... axis

Claims

A sealing device disposed between a fixed inner member and a rotating outer member for sealing a gap between the inner member and the outer member, comprising:
a sleeve attached to the inner member and a first sealing member having a flange extending radially outwardly from the sleeve;
A tubular portion disposed radially outward of the flange and attached to the outer member, a disk portion extending radially inward from the tubular portion and facing the flange, and disposed radially inward of the disk portion. a second seal member having a radial lip that is formed to slidably contact the sleeve and a side lip that extends from the disk portion toward the flange;
the side lip of the second seal member slidably contacts the flange when the rotational speed of the outer member is less than a threshold; and when the rotational speed of the outer member is greater than the threshold, A sealing device, characterized in that it deforms away from said flange.
A sealing device disposed between a rotating inner member and a stationary outer member for sealing a gap between the inner member and the outer member, comprising:
a first sealing member attached to the outer member;
a second seal member attached to the inner member;
The first sealing member has a first rigid ring that is an annular member around an axis formed of a rigid material,
The second sealing member includes a second rigid ring that is an annular member formed of a rigid material around the axis, and a second elastic ring that is an annular member formed of an elastic material around the axis. and
The second elastic ring of the second sealing member has a side lip which is an annular portion around the axis extending along the axis,
The first rigid ring of the first sealing member is in contact with the tip of the side lip,
The side lip of the second seal member slidably contacts the first rigid ring of the first seal member and the inner member when the rotation speed of the inner member is less than a threshold value. is greater than a threshold value, the sealing device deforms so as to move away from the first rigid ring of the first sealing member.
The side lip of the second seal member deforms away from the first rigid ring of the first seal member when the rotational speed of the inner member is greater than a threshold. 3. The sealing device according to item 2.
The first seal member and the second seal member form an annular first gap closer to the gap between the inner member and the outer member than the side lip, 4. The seal according to claim 2, further comprising an annular second gap formed on the side of the side lip away from the gap between the inner member and the outer member. Device.
5. A labyrinth lip according to claim 4, wherein said second elastic ring has a labyrinth lip which is an annular portion about said axis projecting towards said second gap to form a labyrinth seal. sealing device.
The first seal member has a first elastic ring that is an annular member formed of an elastic material around the axis,
5. The sealing device according to claim 4, wherein said first elastic ring has a ring-shaped seal lip around said axis which is a portion that closes said first gap.
The second elastic ring has an annular seal projection around the axis line that closes the first gap,
5. The sealing device according to claim 4, wherein the seal projection protrudes along the axis and is formed to contact the first rigid ring from the axis side.
5. The sealing device of claim 4, wherein said first gap forms a labyrinth seal and said second gap forms a labyrinth seal.