Sealing device

Abstract

The utility model provides a sealing device which can restrain leakage of a sealed object even if the sealing device is used for a shaft rotating at a high speed in the forward rotation direction and the reverse rotation direction. The sealing device (1) comprises a reinforcing ring (10) and an elastic body part (20). A lip tip section (22) of a seal lip (21) of an elastic body section has a seal side surface (24) and an atmospheric side surface (23) which are connected via a lip tip (22a). A plurality of protruding structures (2) are arranged on the atmosphere side surface in the circumferential direction. The projection structure has a first projection (31) and a second projection (32) adjacent to each other in the circumferential direction. The first protrusion is a protrusion for returning the object to be sealed, which leaks when the rotating shaft rotates in the forward direction, to the object to be sealed by a pumping action. The second protrusion is a protrusion for returning the object to be sealed, which leaks when the rotating shaft rotates in the reverse direction, to the object to be sealed by pumping action.

Description

Technical Field

[0001] The utility model relates to a sealing device. Background Art

[0002] In recent years, in electric vehicles, there is a tendency to increase the rotation speed of the motor shaft in order to make the drive unit small and light. In addition, in electric vehicles, the rotation direction of the motor is reversed when moving forward and when moving backward.

[0003] Here, in automobiles, general machinery, etc., oil seals have been used as sealing devices to seal the gap between the rotating shaft and the through hole of the housing through which the rotating shaft is inserted. The oil seal prevents the oil of the sealed object from leaking from the sealed object side where the sealed object exists to the atmosphere side. In the existing oil seal, there are multiple threaded protrusions arranged at equal intervals, which form an airflow from the atmosphere side to the sealed object side, and play a pumping role to push the oil droplets that have leaked to the atmosphere side over the front end of the lip when the rotating shaft rotates at high speed back to the sealed object side (for example, refer to patent document 1).

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Patent No. 3278349. Utility Model Content

[0007] Problems to be solved by the utility model

[0008] When conventional oil seals are used for rotating shafts that rotate in both the forward and reverse directions, such as the shaft of an electric vehicle motor, when the rotating shaft rotates in the reverse direction at high speed, the threaded protrusions may not perform a pumping function from the atmosphere to the sealed object. Therefore, when the rotating shaft rotates in the reverse direction at high speed, the sealed object such as oil may leak to the atmosphere along the threaded protrusions.

[0009] As described above, the sealing device is required to have a structure capable of preventing leakage of a sealed object such as oil even when used for a shaft that rotates at high speed in both the forward and reverse directions.

[0010] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a sealing device capable of suppressing leakage of a sealed object even when used for a shaft that rotates at high speed in both the forward and reverse directions.

[0011] Means used to solve problems

[0012] In order to achieve the above-mentioned purpose, the sealing device involved in the utility model is used for a rotating shaft that rotates in one direction and another direction, and includes: a reinforcement ring, which is annular around the axis; and an elastic body part, which is annular around the axis, has a sealing lip, and is formed by an elastomer installed on the reinforcement ring, the sealing lip has a lip front end portion, the lip front end portion is an annular portion protruding toward the axis, the lip front end portion has a sealing side surface and an atmospheric side surface connected via the lip front end, the sealing side surface is an annular surface on the sealing object side, the atmospheric side surface is an annular surface on the atmospheric side, and a plurality of protrusion structures are arranged in a circumferential direction on the atmospheric side surface, the protrusion structure has a first protrusion and a second protrusion adjacent to each other in the circumferential direction, the first protrusion is a protrusion for returning the sealing object leaked out when the rotating shaft rotates in the one direction to the sealing object side through a pumping action, and the second protrusion is a protrusion for returning the sealing object leaked out when the rotating shaft rotates in the other direction to the sealing object side through a pumping action.

[0013] In a sealing device according to one embodiment of the present invention, the first protrusion extends obliquely from the sealing object side toward the atmosphere side along the other circumferential direction, and the second protrusion extends obliquely from the sealing object side toward the atmosphere side along one circumferential direction.

[0014] In the sealing device according to one aspect of the present invention, an end portion of the first protrusion on the atmosphere side and an end portion of the second protrusion on the atmosphere side in the protrusion structure are connected to each other.

[0015] In a sealing device according to one embodiment of the present invention, a circumferential width between an end portion of the first protrusion on the atmosphere side and an end portion of the second protrusion on the atmosphere side in the protrusion structure is smaller than a circumferential width between two protrusion structures adjacent to each other in the circumferential direction.

[0016] In a sealing device involved in one embodiment of the present invention, the circumferential width between the end of the first protrusion on the atmosphere side and the end of the second protrusion on the atmosphere side in the protrusion structure is the width of a flow path that can be formed between the first protrusion and the second protrusion to return the sealed object to the sealed object side when the rotating shaft rotates.

[0017] In the sealing device according to one aspect of the present invention, in the protrusion structure, the first protrusion and the second protrusion extend from the lip tip toward the atmosphere side.

[0018] In a sealing device involved in one embodiment of the present invention, the multiple protrusion structures include multiple first protrusion structures and multiple second protrusion structures, and the multiple second protrusion structures are arranged so that the ends of the multiple second protrusion structures on the sealing object side are closer to the atmosphere side in the axial direction than the ends of the multiple first protrusion structures on the sealing object side, and are respectively arranged in the circumferential direction between the first protrusion structures adjacent to each other in the multiple first protrusion structures.

[0019] In a sealing device according to one embodiment of the present invention, heights of the first protrusion and the second protrusion of the second protrusion structure from the atmosphere side surface are greater than heights of the first protrusion and the second protrusion of the first protrusion structure from the atmosphere side surface.

[0020] In a sealing device involved in one embodiment of the present invention, the multiple protrusion structures include multiple third protrusion structures, and the multiple third protrusion structures are arranged so that the ends of the multiple third protrusion structures on the sealing object side are closer to the atmosphere side in the axial direction than the ends of the multiple second protrusion structures on the sealing object side, and are respectively arranged in the circumferential direction between the second protrusion structures adjacent to each other in the multiple second protrusion structures.

[0021] In the sealing device according to one aspect of the present invention, heights of the first protrusion and the second protrusion of the third protrusion structure from the atmosphere side surface are greater than heights of the first protrusion and the second protrusion of the second protrusion structure from the atmosphere side surface.

[0022] In a sealing device according to one embodiment of the present invention, the protrusion structure includes a third protrusion extending obliquely in another circumferential direction from the sealed object side toward the atmosphere side, and the third protrusion is connected to the end of the first protrusion on the atmosphere side.

[0023] Utility Model Effect

[0024] According to the sealing device of the present invention, even when used for a shaft that rotates at high speed in both the forward and reverse directions, leakage of a sealed object can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a cross-sectional view showing a schematic structure of a sealing device according to a first embodiment of the present invention.

[0026] Figure 2 Yes means Figure 1 An enlarged cross-sectional view of the section shown, on one side relative to the axis.

[0027] Figure 3 yes Figure 1 A partial enlarged view of the sealing device shown.

[0028] Figure 4 It is a cross-sectional view showing the shape of a cross section perpendicular to the extending direction of the first protrusion and the second protrusion.

[0029] Figure 5 Observed along the circumference Figure 1 A partially enlarged cross-sectional view of the first protrusion and the second protrusion of the sealing device is shown.

[0030] Figure 6 Observed along the circumference Figure 1 FIG. 1 is a partially enlarged cross-sectional view of a modified example of the first protrusion and the second protrusion of the sealing device shown.

[0031] Figure 7 It is used to illustrate Figure 1 A partial cross-sectional view of the sealing device in use is shown.

[0032] Figure 8 This is a diagram for explaining the function of the protrusion structure.

[0033] Fig. 9 It is a diagram showing a modified example of the protrusion structure.

[0034] Fig.10 It is a diagram showing a protrusion structure according to another modified example of the protrusion structure.

[0035] Fig.11 It is a diagram showing a protrusion structure according to another modified example of the protrusion structure.

[0036] Fig.12 It is a cross-sectional view showing a schematic structure of a sealing device according to a second embodiment of the present invention.

[0037] Fig.13 yes Fig.12 A partial enlarged view of the sealing device shown.

[0038] Fig.14 This is a schematic diagram showing an example of a drive system to which the sealing device according to the present invention is applied.

[0039] Description of Reference Numerals

[0040] 1, 4 sealing device, 2 protrusion structure (first protrusion structure), 2a space, 3 protrusion structure, 5 second protrusion structure, 6 third protrusion structure, 10 reinforcement ring, 11 cylinder, 12 flange, 20 elastic body, 21 sealing lip, 22 lip front end, 22a lip front end, 23 atmosphere side, 23a outer edge, 24 sealing side, 25 lip waist, 26 dust lip, 27 clamp spring, 28 rear cover, 29 gasket, 31, 34, 36 first protrusion, 31a, 34a, 36a outer end, 31b, 35b, 37b inner end, 32, 35, 37 second protrusion, 32a outer end, 32b inner end, third protrusion, 33a outer end, 33b inner end, 50 rotating shaft, 50a outer circumference, 51 shell, 52 through hole, 52a inner circumference, 100 drive system, 101 motor, 102 transmission, 103 motor shaft, 104 input shaft, 105 intermediate shaft, 106 output shaft, 107 gear, 108 oil, 109 wheel, F1, F2, F3, F4, F5 airflow, S, S1, S2 contact surface, T1, T2, T3 height, x-axis line, W1, W2 width. DETAILED DESCRIPTION

[0041] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in the accompanying drawings, not all of the plurality of components are given reference numerals, and reference numerals of some of the plurality of components may be omitted.

[0042] Figure 1 2 is a cross-sectional view showing a schematic structure of a sealing device 1 according to a first embodiment of the present invention. Figure 2 Yes means Figure 1 The cross section shown is an enlarged cross-sectional view relative to one side of the axis x. In addition, Figure 3 It is a partial enlarged view of the sealing device 1. The sealing device 1 involved in the first embodiment of the utility model is a sealing device for a rotating shaft that rotates in a forward direction as one direction and a reverse direction as another direction. As described later, the sealing device 1 is used to seal the sealed object in a space to be sealed by contacting with the outer peripheral surface of the rotating shaft when it is installed in the use state of the applicable object. The sealing device 1 is used, for example, in the motor of an electric vehicle to seal between the output shaft as the rotating shaft and the housing. In addition, the applicable objects of the sealing device 1 are not limited to such motors of electric vehicles.

[0043] like Figures 1 to 3As shown, the sealing device 1 includes a reinforcement ring 10 and an elastic body portion 20. The reinforcement ring 10 is a member that is annular around the axis x. The elastic body portion 20 is a member that is annular around the axis x and is formed of an elastomer and is mounted on the reinforcement ring 10, and has a sealing lip 21. The sealing lip 21 has a lip front end portion 22 that is an annular portion protruding toward the axis x. The lip front end portion 22 has a sealing side surface 24 and an atmospheric side surface 23 connected via a lip front end 22a, the sealing side surface 24 is an annular surface on the sealing object side, and the atmospheric side surface 23 is an annular surface on the atmospheric side. A plurality of protrusion structures 2 are arranged circumferentially on the atmospheric side surface 23. The protrusion structure 2 has a first protrusion 31 and a second protrusion 32 that are adjacent in the circumferential direction. The first protrusion 31 is a protrusion for returning the sealing object leaking out when the rotating shaft rotates in the forward direction to the sealing object side by a pumping action. The second protrusion 32 is a protrusion for returning the sealing object leaking out when the rotating shaft rotates in the reverse direction to the sealing object side by a pumping action. Hereinafter, the structure of the sealing device 1 will be described in detail.

[0044] Incidentally, the axis x is the central axis of the sealing device 1. In addition, the sealing object side is the side where the sealing object such as oil is to be present. Figure 1 As shown in FIG. 1 , in the direction of the axis x, it is the side in the direction of the arrow a. In addition, the atmospheric side is the side of the atmosphere, which is the side where the sealed object does not exist, such as Figure 1 As shown, in the axis x direction, it is the side in the direction of arrow b. In addition, the direction perpendicular to the axis x direction is defined as the radial direction, the side close to the axis x in the radial direction is defined as the inner peripheral side, and the side far from the axis x in the radial direction is defined as the outer peripheral side.

[0045] The reinforcement ring 10 is, for example, a ring-shaped or substantially ring-shaped component with the axis x as the central axis or substantially the central axis. Figure 1 , Figure 2 As shown, the reinforcement ring 10 includes: a cylindrical portion 11, which is a cylindrical portion extending along the axis x; and a flange portion 12, which is an annular portion extending from the end of the cylindrical portion 11 on the atmosphere side toward the inner peripheral side. The reinforcement ring 10 is made of metal, for example. Examples of the metal material of the reinforcement ring 10 include stainless steel and SPCC (cold rolled steel). In addition, the material of the reinforcement ring 10 is not limited to metal.

[0046] The elastic body 20 is mounted on the reinforcing ring 10, for example Figure 1 , Figure 2As shown, the reinforcing ring 10 is installed in a manner of covering the reinforcing ring 10 from the atmosphere side and the outer peripheral side. The elastomer portion 20 is reinforced by the reinforcing ring 10. The elastomer portion 20 is formed of an elastomer as described above. As the elastomer of the elastomer portion 20, various rubber materials can be listed, for example. As the various rubber materials, there are synthetic rubbers such as nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), and fluororubber (FKM). The elastomer portion 20 is, for example, bonded to the reinforcing ring 10.

[0047] As described above, the elastic body portion 20 has the sealing lip 21, and the sealing lip 21 has the lip front end portion 22 on the inner peripheral side, and the lip front end portion 22 is an annular portion protruding toward the axis x. Figure 1 , Figure 2 As shown, the elastomer part 20 has a lip waist 25. The lip waist 25 is an annular portion located in the elastomer part 20 near the end portion on the inner circumference side of the flange part 12 of the reinforcement ring 10. The sealing lip 21 is connected to the lip waist 25 at its end portion on the atmosphere side and extends inward from the lip waist 25. The sealing lip 21 is configured to be opposite to the cylindrical part 11 of the reinforcement ring 10. In addition, the elastomer part 20 has a dustproof lip 26. The dustproof lip 26 extends from the lip waist 25 toward the atmosphere side and the axis x.

[0048] Specifically, for example, Figure 1 , Figure 2 As shown, the lip tip 22 of the sealing lip 21 is an annular or substantially annular portion with the axis x as the central axis or substantially the central axis, and is formed at the end of the sealing lip 21 on the sealing object side. The cross-sectional shape of the lip tip 22 is a wedge shape that is convex toward the inner peripheral side. The lip tip 22 is formed so that the lip tip 22a on the inner peripheral side and the portion near it are in contact with the outer peripheral surface of the rotating shaft in the use state described later. More specifically, the interference amount of the lip tip 22 with respect to the rotating shaft is set so that the lip tip 22 is in contact with the outer peripheral surface of the rotating shaft over a predetermined width in the direction of the axis x including the lip tip 22a.

[0049] like Figure 1 , Figure 2 As shown, the lip front end portion 22 is divided by an annular atmospheric side surface 23 on the atmospheric side and an annular sealing side surface 24 on the sealed object side, which are connected to each other via the lip front end 22a. The atmospheric side surface 23 is a surface facing the atmospheric side, and is a conical surface or a substantially conical surface that expands in diameter toward the atmospheric side (arrow b direction) in the axis x direction. The sealing side surface 24 is a surface facing the sealed object side, and is a conical surface or a substantially conical surface that expands in diameter toward the inner side (arrow a direction) in the axis x direction.

[0050] The atmosphere side surface 23 and the sealing side surface 24 intersect each other on the small diameter side, and a lip tip 22a is formed at the intersection. The lip tip 22a describes a circle or a substantially circle with the axis x as the center or substantially the center in a cross section perpendicular to the axis x, and is the portion located on the innermost circumference of the lip tip portion 22.

[0051] like Figure 1 , Figure 2 As shown, a recess 21a is formed on the outer peripheral side of the sealing lip 21 in a manner opposite to the lip front end 22, and a clamp spring 27 is embedded in the recess 21a. The clamp spring 27 is, for example, a metal spring member, and in the use state described later, presses the lip front end 22 of the sealing lip 21 toward the inner peripheral side in the radial direction, and applies a predetermined magnitude of pressing force to the lip front end 22 relative to the outer peripheral surface of the rotating shaft.

[0052] like Figure 1 , Figure 2 As shown, the dust lip 26 is a portion extending from the lip waist 25 toward the atmosphere (arrow b direction) and the inner circumference toward the axis x. The dust lip 26 prevents foreign matter such as muddy water, sand, and dust from entering the lip tip 22 from the atmosphere during use as described below.

[0053] In addition, if Figure 1 , Figure 2 As shown, the elastic body portion 20 has a rear cover 28 and a gasket portion 29. The rear cover 28 is a portion that covers the flange portion 12 of the reinforcement ring 10 from the atmosphere side, and the gasket portion 29 is a portion that covers the cylindrical portion 11 of the reinforcement ring 10 from the outer peripheral side. The gasket portion 29 is a portion used to fix the sealing device 1 to a through hole of a component such as a housing through which a rotating shaft passes when the sealing device 1 is used. When the sealing device 1 is installed in the above-mentioned through hole, the gasket portion 29 is compressed in the radial direction between the through hole and the cylindrical portion 11 of the reinforcement ring 10, generating a force in the radial direction, that is, a fitting force. The gasket portion 29 is set in a radial thickness in such a way that a fitting force of a predetermined size is generated when the sealing device 1 is installed in the through hole. As described above, the elastic body portion 20 has the sealing lip 21, the lip waist 25, the dust lip 26, the rear cover 28, and the gasket portion 29, which are formed integrally by the same elastomer.

[0054] As described above, a plurality of protrusion structures 2 are arranged in a circumferential direction on the atmospheric side surface 23 of the lip front end portion 22. Figures 1 to 3 As shown, in the sealing device 1, as an example, a plurality of protrusion structures 2 are arranged in a row in the circumferential direction. The plurality of protrusion structures 2 are arranged, for example, along a circle centered on the axis x, at equal or substantially equal angular intervals around the axis x. In addition, Figure 3 This is a view of the elastic body portion 20 as viewed from the inner peripheral side, showing the lip tip portion 22 and a portion of its vicinity.

[0055] like Figure 2 , Figure 3 As shown, the protrusion structure 2 has a first protrusion 31 and a second protrusion 32. The first protrusion 31 is a threaded protrusion, which plays a pumping role when the rotating shaft rotates in the forward direction in the use state, so that the sealed object leaking to the atmosphere side beyond the lip front end 22a returns to the sealed object side beyond the lip front end 22a. The second protrusion 32 is a threaded protrusion, which plays a pumping role when the rotating shaft rotates in the reverse direction in the use state, so that the sealed object leaking to the atmosphere side beyond the lip front end 22a returns to the sealed object side beyond the lip front end 22a. In addition, the first protrusion 31 plays a pumping role when the rotating shaft rotates in the forward direction in the use state, so that the sealed object leaking to the atmosphere side beyond the lip front end 22a along the second protrusion 32 returns to the sealed object side beyond the lip front end 22a. Similarly, the second protrusion 32 plays a pumping role when the rotating shaft rotates in the reverse direction in the use state, so that the sealing object that has passed through the lip front end 22a along the first protrusion 31 and leaked to the atmosphere side returns to the sealing object side over the lip front end 22a. In addition, the protrusion structure 2 temporarily intercepts and retains the sealing object that has passed through the lip front end 22a and leaked to the atmosphere side when the rotating shaft rotates in the use state.

[0056] like Figure 2 , Figure 3 As shown, the first protrusion 31 is a protrusion protruding from the atmosphere side surface 23, and extends obliquely from the sealing object side toward the atmosphere side in the reverse direction. That is, the first protrusion 31 extends obliquely in the reverse direction relative to the lip front end 22a of the lip front end portion 22 toward the atmosphere side. Therefore, in the first protrusion 31, the outer end 31a as the end on the atmosphere side is located at a position farther away from the reverse direction side in the circumferential direction than the inner end 31b as the end on the sealing object side. When the first protrusion 31 rotates forward in the state of use, an airflow from the atmosphere side toward the sealing object side is generated along the first protrusion 31.

[0057] For example, Figure 2 , Figure 3 As shown, the first protrusion 31 extends from the lip front end 22a, and the inner end 31b of the first protrusion 31 is located at the lip front end 22a. Figure 2 , Figure 3 As shown, the first protrusion 31 does not reach the outer edge 23a which is the edge of the atmosphere side of the atmosphere side surface 23. The outer end 31a of the first protrusion 31 is located at a position away from the lip front end 22a toward the atmosphere side in the axis x direction by a predetermined distance, and the first protrusion 31 extends from the lip front end 22a to a position away from the atmosphere side surface 23 in the axis x direction by a predetermined distance.

[0058] Figure 4 : is a cross-sectional view showing the shape of a cross section perpendicular to the extending direction of the first protrusion 31 (hereinafter also referred to as the cross-sectional shape). Figure 4As shown in FIG. 1 , the first protrusion 31 is a triangle or a substantially triangle that protrudes toward the inner circumference. Specifically, the cross-sectional shape of the first protrusion 31 is, for example, Figure 4 The cross-sectional shape of the first protrusion 31 is not limited to this, and may also be an isosceles triangle, other triangles, or approximate triangles. In addition, the cross-sectional shape of the first protrusion 31 is not limited to a triangle, and may also be a quadrilateral or other polygon, a cross section of an arc or an arc, a cross section of a curve, a cross section of a line formed by a combination of multiple straight lines, a cross section of a line formed by a combination of one or more curves and one or more straight lines, etc. The cross-sectional shape of the first protrusion 31 is preferably a shape that is symmetrical with respect to a line orthogonal to the atmospheric side surface 23, such as an equilateral triangle or an isosceles triangle.

[0059] As an example, Figure 5 As shown, the first protrusions 31 are parallel protrusions, and the height T1 of the first protrusions 31 is constant or substantially constant as a whole. Figure 5 It is a partially enlarged cross-sectional view of the first protrusion 31 as viewed along the circumferential direction. Figure 6 3 is a diagram showing a modified example of the first protrusion 31, and is a partially enlarged cross-sectional view of the modified example of the first protrusion 31 observed along the circumferential direction. Figure 6 As shown, the first protrusion 31 may also be a protrusion on the bottom of the ship. In this case, the height T1 of the first protrusion 31 is not constant as a whole, and increases from the inner end 31b toward the outer end 31a. In addition, the height T1 of the first protrusion 31 may also increase from the inner end 31b toward the outer end 31a to a predetermined position, and decrease from the predetermined position. In addition, the height T1 of the first protrusion 31 is the protrusion amount from the atmospheric side surface 23, which is the distance from the atmospheric side surface 23 in the direction orthogonal to the atmospheric side surface 23.

[0060] The second protrusion 32 is a protrusion extending obliquely in the direction opposite to the first protrusion 31, and has, for example, the same or substantially the same shape and size as the first protrusion 31. Figure 2 , Figure 3 As shown, the second protrusion 32 is a protrusion protruding from the atmosphere side surface 23, and extends obliquely from the sealing object side toward the atmosphere side in the normal rotation direction. That is, the second protrusion 32 extends obliquely toward the atmosphere side, relative to the lip front end 22a of the lip front end portion 22, in the normal rotation direction. Therefore, in the second protrusion 32, the outer end 32a as the end on the atmosphere side is located at a position farther away from the positive rotation direction side in the circumferential direction than the inner end 32b as the end on the sealing object side. When the second protrusion 32 is used and the rotating shaft is reversed, an airflow from the atmosphere side toward the sealing object side is generated along the second protrusion 32.

[0061] For example, Figure 2 , Figure 3As shown, the second protrusion 32 extends from the lip front end 22a, and the inner end 32b of the second protrusion 32 is located at the lip front end 22a. In addition, for example, Figure 2 , Figure 3 As shown, the second protrusion 32 does not reach the outer edge 23a of the atmosphere side surface 23. The outer end 32a of the second protrusion 32 is located at a position away from the lip front end 22a to the atmosphere side along the axis x direction by a predetermined distance, and the second protrusion 32 extends from the lip front end 22a to a position away from the atmosphere side surface 23 along the axis x direction by a predetermined distance.

[0062] like Figure 4 As shown in FIG. 1 , the cross-sectional shape of the second protrusion 32 has the same or substantially the same cross-sectional shape as the first protrusion 31. In addition, as an example, Figure 5 As shown, the second protrusions 32 are parallel protrusions, and the height T2 of the second protrusions 32 is constant or substantially constant as a whole. Figure 6 As shown, the second protrusion 32 may also be a protrusion on the bottom of the ship. In this case, the height T2 of the second protrusion 32 is not constant as a whole, and increases from the inner end 32b toward the outer end 32a. In addition, the height T2 of the second protrusion 32 may also increase from the inner end 32b toward the outer end 32a to a specified position, and decrease from the specified position. For example, the shape and size of the second protrusion 32 are the same or substantially the same as the shape and size of the first protrusion 31. In addition, the height T2 of the second protrusion 32 is the same or substantially the same as the height T1 of the first protrusion 31. In addition, the height T2 of the second protrusion 32 is the protrusion amount from the atmospheric side surface 23, and is the distance from the atmospheric side surface 23 in a direction orthogonal to the atmospheric side surface 23.

[0063] like Figure 2 , Figure 3 As shown, in the protrusion structure 2, the outer end 31a of the first protrusion 31 is connected to the outer end 32a of the second protrusion 32. That is, the outer end 31a of the first protrusion 31 overlaps the outer end 32a of the second protrusion 32. In this way, the protrusion structure 2 is a V-shaped protrusion.

[0064] The inner end 31b of the first protrusion 31 and the inner end 32b of the second protrusion 32 are located at the lip tip 22a. In the use state, the lip tip 22a in contact with the rotating shaft floats from the outer peripheral surface of the rotating shaft near the inner end 31b of the first protrusion 31 and the inner end 32b of the second protrusion 32. The floating amount of the lip tip 22a from the rotating shaft caused by the first protrusion 31 and the second protrusion 32 corresponds to the height of the first protrusion 31 and the second protrusion 32, and becomes larger as the height of the first protrusion 31 and the second protrusion 32 is high. Therefore, in the use state, the lower the height T1 and T2 of the first protrusion 31 and the second protrusion 32, the more uniform the contact between the lip tip 22 and the rotating shaft is, and the more stable the contact is. The higher the height T1 and T2 of the first protrusion 31 and the second protrusion 32, the more uneven the contact between the lip tip 22 and the rotating shaft is, and the more unstable the contact is. Therefore, the heights T1 and T2 of the first protrusion 31 and the second protrusion 32 are set, for example, so that the sealing device 1 has a desired sealing performance.

[0065] In the case where the first protrusion 31 and the second protrusion 32 are parallel protrusions, if the lip tip portion 22 is worn due to sliding relative to the rotating shaft and a part of the first protrusion 31 and the second protrusion 32 is worn, there is a case where the radial distance between the first protrusion 31 and the second protrusion 32 and the outer peripheral surface of the rotating shaft is separated, and the pumping effect of the first protrusion 31 and the second protrusion 32 is reduced or lost. In contrast, in the case where the first protrusion 31 and the second protrusion 32 are ship bottom protrusions, even if the lip tip portion 22 is worn due to sliding relative to the rotating shaft and a part of the first protrusion 31 and the second protrusion 32 is worn, the change in the radial distance between the first protrusion 31 and the second protrusion 32 and the outer peripheral surface of the rotating shaft can be suppressed or prevented. Therefore, in the case where the first protrusion 31 and the second protrusion 32 are ship bottom protrusions, even if a part of the first protrusion 31 and the second protrusion 32 is worn, the reduction in the ability of the pumping effect of the first protrusion 31 and the second protrusion 32 can be suppressed.

[0066] Next, the operation of the sealing device 1 having the above-mentioned structure will be described. Figure 7 1 is a partial cross-sectional view for explaining the use state of the sealing device 1. The sealing device 1 is installed in the space between the rotating shaft 50 and the through hole 52 in order to seal between the rotating shaft 50 and the housing 51 having the through hole 52 through which the rotating shaft 50 passes in the use state. The rotating shaft 50 is, for example, the output shaft of a driving motor of an automobile, and the housing 51 is, for example, a cover of the motor.

[0067] like Figure 7As shown, in the use state, the sealing device 1 is pressed into the through hole 52 installed in the housing 51, and the gasket portion 29 of the elastic body portion 20 is compressed between the housing 51 and the reinforcement ring 10 and contacts the inner peripheral surface 52a of the through hole 52. As a result, the sealing device 1 and the through hole 52 of the housing 51 are sealed. In addition, the lip tip portion 22 of the sealing lip 21 contacts the outer peripheral surface 50a of the rotating shaft 50 in a manner that the rotating shaft 50 can slide, and the sealing device 1 and the rotating shaft 50 are sealed. Specifically, in the contact surface S, which is a portion of the lip tip portion 22 including the lip tip 22a and has a range with a width in the direction of the axis x, the lip tip portion 22 contacts the outer peripheral surface 50a of the rotating shaft 50. As a result, the oil as the sealing object is sealed to the sealing object side.

[0068] In addition, at least a portion of the first protrusion 31 and the second protrusion 32 of each protrusion structure 2 contacts the outer peripheral surface 50a of the rotating shaft 50. For example, the first protrusion 31 and the second protrusion 32 contact the outer peripheral surface 50a of the rotating shaft 50 at the contact surfaces S1 and S2 that are continuous from the inner ends 31b and 32b, respectively (see the following description). Figure 8 ).

[0069] Figure 8 2 is a diagram for explaining the function of the protrusion structure 2. Figure 8 FIG. 2 schematically shows the protrusion structure 2 in contact with the outer peripheral surface 50a of the rotating shaft 50. In the protrusion structure 2, the first protrusion 31 is arranged to face the atmosphere and to be inclined toward the reverse direction of the rotating shaft 50. Therefore, in the above-described use state, when the rotating shaft 50 rotates in the forward direction, as shown in FIG. Figure 8 As shown, an airflow F1 is generated that flows from the atmosphere side to the sealed object side along the first protrusion 31. This airflow F1 provides a pumping action that acts to return the oil droplets that have leaked over the contact surface S from the atmosphere side to the sealed object side. Therefore, the oil droplets that have leaked over the contact surface S of the lip front end portion 22 to the atmosphere side are pushed back over the contact surface S to the sealed object side by the pumping action of the first protrusion 31.

[0070] On the other hand, in the protrusion structure 2, the second protrusion 32 is arranged to face the atmosphere side and to be inclined toward the positive rotation direction of the rotating shaft 50. Therefore, in the above-described use state, when the rotating shaft 50 rotates in the positive rotation direction, as shown in FIG. Figure 8As shown, an airflow F2 is generated that flows along the second protrusion 32 from the sealed object side to the atmosphere side. Due to the airflow F2, oil droplets are sometimes discharged from the sealed object side to the atmosphere side. Here, in the protrusion structure 2, the first protrusion 31 that plays a pumping role in returning the oil droplets to the sealed object side when the rotating shaft 50 rotates in the positive direction is connected to the second protrusion 32 on the downstream side of the airflow F2 generated by the second protrusion 32. Therefore, the oil droplets discharged from the sealed object side to the atmosphere side due to the airflow F2 are pushed back to the sealed object side by the pumping action of the first protrusion 31.

[0071] In this way, when the rotating shaft 50 rotates in the forward direction, the protrusion structure 2 can return the oil droplets released to the atmosphere side due to the second protrusion 32 to the sealed object side through the first protrusion 31 in addition to the oil droplets that leak to the atmosphere side over the contact surface S of the lip front end portion 22. The higher the rotation speed of the rotating shaft 50, the more the oil droplets released to the atmosphere side due to the second protrusion 32 increase. As described above, the protrusion structure 2 can return the oil droplets released to the atmosphere side due to the second protrusion 32 to the sealed object side through the first protrusion 31. Therefore, even if the rotating shaft 50 rotates at a high speed in the forward direction, the protrusion structure 2 can suppress or prevent the leakage of oil. In this way, even if the rotating shaft 50 rotates at a high speed in the forward direction, the sealing device 1 can suppress or prevent the leakage of oil. For example, the sealing device 1 can suppress or prevent the leakage of oil even if the rotating shaft 50 rotates at a high speed in the forward direction at a circumferential speed of 50m / s.

[0072] On the other hand, when the rotating shaft 50 rotates in the reverse direction in the above-mentioned use state, Figure 8 As shown, in the protrusion structure 2, the first protrusion 31 and the second protrusion 32 function opposite to the case of rotation in the normal direction, and the protrusion structure 2 can suppress or prevent oil leakage similarly to the case of rotation in the normal direction.

[0073] That is, when the rotating shaft 50 rotates in the reverse direction, an airflow F3 is generated that flows from the atmosphere side to the sealed object side along the second protrusion 32. The airflow F3 can provide a pumping effect, which plays a role in returning the oil droplets from the atmosphere side to the sealed object side. Therefore, the oil droplets that have leaked to the atmosphere side over the contact surface S of the lip front end portion 22 are pushed back to the sealed object side over the contact surface S by the pumping effect of the second protrusion 32.

[0074] On the other hand, in the protrusion structure 2, as Figure 8As shown, the first protrusion 31 generates an airflow F4 that flows along the first protrusion 31 from the sealed object side to the atmosphere side. Due to the airflow F4, oil droplets are sometimes discharged from the sealed object side to the atmosphere side. Here, in the protrusion structure 2, the second protrusion 32 that plays a pumping role in returning the oil droplets to the sealed object side when the rotating shaft 50 rotates in the reverse direction is connected to the first protrusion 31 on the downstream side of the airflow F4 generated by the first protrusion 31, and the oil droplets discharged from the sealed object side to the atmosphere side due to the airflow F4 are pushed back to the sealed object side by the pumping action of the second protrusion 32.

[0075] In this way, when the rotating shaft 50 rotates in the reverse direction, the protrusion structure 2 can return the oil droplets released to the atmosphere side due to the first protrusion 31 to the sealed object side through the second protrusion 32, in addition to the oil droplets that leak to the atmosphere side over the contact surface S of the lip front end portion 22. Therefore, even if the rotating shaft 50 rotates in the reverse direction at a high speed, the protrusion structure 2 can suppress or prevent the leakage of oil. In this way, even if the rotating shaft 50 rotates in the reverse direction at a high speed, the sealing device 1 can suppress or prevent the leakage of oil. For example, even if the rotating shaft 50 rotates in the reverse direction at a circumferential speed of 50m / s, the sealing device 1 can suppress or prevent the leakage of oil.

[0076] In addition, if Figure 8 As shown, in the protrusion structure 2, the first protrusion 31 and the second protrusion 32 are connected on the atmosphere side to form a V-shaped protrusion, so that the space 2a enclosed on the atmosphere side is formed by the first protrusion 31 and the second protrusion 32. Therefore, the protrusion structure 2 can intercept the oil droplets that leak to the atmosphere side across the contact surface S and retain them in the space 2a, and function as a dam for the oil droplets that leak to the atmosphere side. In addition, the protrusion structure 2 can return the oil retained in the space 2a to the sealed object side across the contact surface S through the pumping action of the airflow F1 or the airflow F3. The protrusion structure 2 can also suppress or prevent oil leakage through this action.

[0077] As described above, the sealing device 1 according to the first embodiment of the present invention can suppress leakage of the sealed object even when used for the rotating shaft 50 that rotates at high speed in both the forward and reverse directions. In addition, in the above description, as an example, the oil as the sealed object leaks in the form of droplets, but this is an example of the leakage mode of the sealed object, and the leakage mode of the sealed object is not limited to the leakage in the form of droplets. For example, the leakage mode of the sealed object may also be a leakage mode in which the sealed object seeps out from the contact surface S.

[0078] In addition, in the protrusion structure 2, as described above, if when the rotating shaft 50 rotates in the forward direction, the first protrusion 31 pushes the oil droplets discharged over the contact surface S to the atmosphere side due to the second protrusion 32 back to the sealing object side, and if, when the rotating shaft 50 rotates in the reverse direction, the second protrusion 32 pushes the oil droplets discharged over the contact surface S to the atmosphere side due to the first protrusion 31 back to the sealing object side, then the first protrusion 31 and the second protrusion 32 may not be connected on the atmosphere side.

[0079] Fig. 9 2 is a diagram showing a modified example of the protrusion structure 2. Fig. 9 As shown, the outer end 31a of the first protrusion 31 and the outer end 32a of the second protrusion 32 may also be separated in the circumferential direction. In this case, the circumferential width W1 between the outer end 31a of the first protrusion 31 and the outer end 32a of the second protrusion 32 in the protrusion structure 2 is, for example, smaller than the circumferential width W2 between two protrusion structures 2 adjacent to each other in the circumferential direction (see Figure 3 Specifically, for example, the width W1 between the outer end 31a and the outer end 32a is the width of the flow path P1, P2 that can be formed between the first protrusion 31 and the second protrusion 32 to return the leaked oil to the sealed object side when the rotating shaft 50 rotates in the forward direction or the reverse direction. Fig. 9 As shown in FIG. 1 , the flow path P1 for returning the leaked oil to the sealed object side is a flow path for returning the oil discharged by the air flow F2 to the sealed object side through the air flow F1, and the flow path formed by the air flow F2 is connected to the flow path formed by the air flow F1. Fig. 9 As shown, the flow path P2 for returning oil to the sealed object side is a flow path for returning the oil discharged by the airflow F4 to the sealed object side through the airflow F3, and is a flow path formed by the airflow F4 and the flow path formed by the airflow F3 are connected.

[0080] Next, other modified examples of the protrusion structure 2 will be described. Fig.10 , Fig.11 It is a diagram showing a protrusion structure 3 according to another modified example of the protrusion structure 2. Fig.10 This is a diagram of the protrusion structure 3 viewed from the inner circumference side. Fig.11 3 is a diagram of the protrusion structure 3 observed along the circumferential direction. Fig.10 As shown, the protrusion structure 3 has a third protrusion 33 as a ship bottom protrusion in addition to the first protrusion 31 and the second protrusion 32 of the protrusion structure 2. The third protrusion 33 is located on the atmosphere side of the first protrusion 31 and the second protrusion 32, and the first protrusion 31 and the second protrusion 32 are integrally connected to the third protrusion 33. Specifically, as shown in FIG. Fig.10As shown, the third protrusion 33 is connected to the outer end 31a of the first protrusion 31 and extends toward the atmosphere along the first protrusion 31. The third protrusion 33 extends parallel to or substantially parallel to the first protrusion 31, for example.

[0081] like Fig.11 As shown in FIG. 1 , the height T3 of the third protrusion 33 as the protrusion on the bottom of the ship is greater than the height T1 of the first protrusion 31, and increases from the inner end 33b toward the outer end 33a to a predetermined position, and decreases from the predetermined position. In addition, the outer end 33a of the third protrusion 33 is the end of the third protrusion 33 on the sealing object side, and the inner end 33b of the third protrusion 33 is the end of the third protrusion 33 on the atmosphere side. In addition, the cross-sectional shape of the third protrusion 33 is the same shape as the cross-sectional shape of the first protrusion 31.

[0082] The third protrusion 33, like the first protrusion 31, generates an airflow F5 flowing along the third protrusion 33 from the atmosphere side to the sealing object side when the rotating shaft 50 rotates in the forward direction, and exerts a pumping effect. In addition, the third protrusion 33 is located on the atmosphere side in the axis x direction relative to the first protrusion 31, and the atmosphere side surface 23 of the lip tip 22 is expanded toward the atmosphere side in the axis x direction. Therefore, when the lip tip 22 is worn and the contact surface S overlaps with the third protrusion 33, the third protrusion 33 has a width in the axis x direction and contacts the outer peripheral surface 50a of the rotating shaft 50. Therefore, even if the lip tip 22 is worn and the first protrusion 31 and the second protrusion 32 are worn, the third protrusion 33 contacts the outer peripheral surface 50a of the rotating shaft 50, and when the rotating shaft 50 rotates in the forward direction, the pumping effect of returning the leaked oil from the atmosphere side to the sealing object side via the contact surface S is continuously exerted. In this way, according to the protrusion structure 3, the pumping effect capability of the protrusion structure 2 can be improved. Furthermore, according to the protrusion structure 3 , the pumping action can be continued for a long period of time despite the progress of wear of the lip tip portion 22 .

[0083] Next, a sealing device 4 according to a second embodiment of the present invention will be described. Fig.12 2 is a cross-sectional view showing a schematic structure of a sealing device 4 according to a second embodiment of the present invention. Fig.13 It is a partial enlarged view of the sealing device 4. In addition, Fig.13 This is a view of the elastic body portion 20 viewed from the inner peripheral side, showing the lip front end portion 22 and a portion of the vicinity thereof. The sealing device 4 is different from the above-mentioned sealing device 1 in that it has a plurality of protrusion structures as protrusion structures. Hereinafter, regarding the structure of the sealing device 4, the description of the same structure or structure having the same function as the sealing device 1 will be omitted, and the different structures will be described.

[0084] like Fig.12As shown, the protrusion structure of the sealing device 4 includes three protrusion structures. That is, the sealing device 4 has a plurality of first protrusion structures 2, a plurality of second protrusion structures 5, and a plurality of third protrusion structures 6 as protrusion structures. The plurality of first protrusion structures 2 are the plurality of protrusion structures 2 of the sealing device 1 described above.

[0085] The second protrusion structure 5 and the third protrusion structure 6 have the same or similar shape as the first protrusion structure 2, and when in contact with the outer peripheral surface 50a of the rotating shaft 50, they function in the same manner as the protrusion structure 2 of the sealing device 1 described above. For example, when the contact surface S overlaps with the second protrusion structure 5 or the third protrusion structure 6 due to wear of the lip tip portion 22, the second protrusion structure 5 or the third protrusion structure 6 contacts the outer peripheral surface 50a of the rotating shaft 50.

[0086] like Fig.12 , Fig.13 As shown, the plurality of second protrusion structures 5 are arranged in a circumferential direction on the atmospheric side surface 23 of the lip front end portion 22 in the same manner as the plurality of first protrusion structures 2. Fig.12 , Fig.13 As shown, the plurality of second protrusion structures 5 are arranged, for example, along a circle centered on the axis x, at equal or substantially equal angular intervals around the axis x. In addition, the plurality of second protrusion structures 5 are arranged so that the ends of the plurality of second protrusion structures 5 on the sealing object side are closer to the atmosphere side in the direction of the axis x than the inner ends 31b of the first protrusion 31 and the inner ends 32b of the second protrusion 32 which are the ends of the plurality of first protrusion structures 2 on the sealing object side, and are respectively arranged between two adjacent first protrusion structures 2 in the circumferential direction.

[0087] In addition, if Fig.12 , Fig.13 As shown, the plurality of third protrusion structures 6 are arranged in a circumferential direction on the atmospheric side surface 23 of the lip front end portion 22 in the same manner as the plurality of first protrusion structures 2. Fig.12 , Fig.13 As shown, the plurality of third protrusion structures 6 are arranged, for example, along a circle centered on the axis x, at equal or substantially equal angular intervals around the axis x. In addition, the plurality of third protrusion structures 6 are arranged so that the ends of the plurality of third protrusion structures 6 on the sealing object side are closer to the atmosphere side than the ends of the plurality of second protrusion structures 5 on the sealing object side in the axis x direction, and are respectively arranged between two second protrusion structures 5 adjacent to each other in the circumferential direction.

[0088] like Fig.12 , Fig.13As shown, the second protrusion structure 5 has a first protrusion 34 and a second protrusion 35 , and the first protrusion 34 and the second protrusion 35 have the same shape and the same function as the first protrusion 31 and the second protrusion 32 of the first protrusion structure 2 .

[0089] like Fig.12 , Fig.13 As shown, the first protrusion 34 is a protrusion protruding from the atmosphere side 23, and extends obliquely in the reverse direction from the sealed object side toward the atmosphere side. The cross-sectional shape of the first protrusion 34 is the same or substantially the same as the cross-sectional shape of the first protrusion 31 of the first protrusion structure 2 (see Figure 4 ). In addition, as an example, the first protrusion 34 is a protrusion on the bottom of the ship (see Figure 6 ). That is, the height of the first protrusion 34 is not constant as a whole, and increases from the inner end 34b toward the outer end 34a. In addition, the height of the first protrusion 34 as a protrusion on the bottom of the ship may increase from the inner end 34b toward the outer end 34a to a predetermined position, and decrease from the predetermined position. In addition, the first protrusion 34 may also be a parallel protrusion (refer to Figure 5 ). In addition, the inner end 34b and the outer end 34a of the first protrusion 34 are the end of the sealing object side and the end of the atmosphere side of the first protrusion 34, respectively. In addition, the height of the first protrusion 34 is the protrusion amount from the atmosphere side surface 23, which is the distance from the atmosphere side surface 23 in the direction orthogonal to the atmosphere side surface 23.

[0090] The second protrusion 35 is a protrusion extending obliquely in the opposite direction to the first protrusion 34, and has, for example, the same or substantially the same shape and size as the first protrusion 34. Fig.12 , Fig.13 As shown, the second protrusion 35 is a protrusion protruding from the atmosphere side 23, and extends obliquely from the sealed object side toward the atmosphere side along the normal rotation direction. The cross-sectional shape of the second protrusion 35 is the same or substantially the same as the cross-sectional shape of the second protrusion 32 of the first protrusion structure 2 (refer to Figure 4 ). In addition, as an example, the second protrusion 35 is a protrusion on the bottom of the ship (see Figure 6 ). That is, the height of the second protrusion 35 is not constant as a whole, and increases from the inner end 35b toward the outer end 35a. In addition, the height of the second protrusion 35 as a protrusion on the bottom of the ship may increase from the inner end 35b toward the outer end 35a to a predetermined position, and decrease from the predetermined position. In addition, the second protrusion 35 may also be a parallel protrusion (refer to Figure 5 ). In addition, the inner end 35b and the outer end 35a of the second protrusion 35 are respectively the end of the sealing object side and the end of the atmosphere side of the second protrusion 35. In addition, the height of the second protrusion 35 is the protrusion amount from the atmosphere side surface 23, which is the distance from the atmosphere side surface 23 in the direction orthogonal to the atmosphere side surface 23.

[0091] like Fig.12 , Fig.13 As shown, in the second protrusion structure 5, the outer end 34a of the first protrusion 34 is connected to the outer end 35a of the second protrusion 35. That is, the outer end 34a of the first protrusion 34 overlaps the outer end 35a of the second protrusion 35. In this way, the protrusion structure 2 is a V-shaped protrusion.

[0092] The inner end 34b of the first protrusion 34 and the inner end 35b of the second protrusion 35, which are the ends on the sealing object side of the second protrusion structure 5, are arranged on the atmosphere side in the axis x direction compared with the inner end 31b of the first protrusion 31 and the inner end 32b of the second protrusion 32 of the first protrusion structure 2. Fig.11 As shown, the inner end 34b of the first protrusion 34 and the inner end 35b of the second protrusion 35 of the second protrusion structure 5 are located on the atmosphere side in the axis x direction compared to the inner end 31b of the first protrusion 31 and the inner end 32b of the second protrusion 32 of the first protrusion structure 2, and are located on the sealed object side in the axis x direction compared to the outer end 31a of the first protrusion 31 and the outer end 32a of the second protrusion 32 of the first protrusion structure 2. It should be noted that the inner end 34b of the first protrusion 34 and the inner end 35b of the second protrusion 35 of the second protrusion structure 5 may also be located on the atmosphere side in the axis x direction compared to the outer end 31a of the first protrusion 31 and the outer end 32a of the second protrusion 32 of the first protrusion structure 2.

[0093] As described above, the second protrusion structure 5 is located on the atmospheric side in the axis x direction compared to the first protrusion structure 2, and the atmospheric side surface 23 of the lip tip portion 22 is expanded toward the atmospheric side in the axis x direction. Fig.13 As shown, the height of the first protrusion 34 and the height of the second protrusion 35 of the second protrusion structure 5 are greater than the height of the first protrusion 31 and the height of the second protrusion 32 of the first protrusion structure 2, so that when the front end portion 22 of the lip is worn and the contact surface S overlaps with multiple second protrusion structures 5, the first protrusion 34 and the second protrusion 35 have a width in the direction of the axis x and contact the outer peripheral surface 50a of the rotating shaft 50.

[0094] like Fig.12 , Fig.13 As shown, the third protrusion structure 6 has a first protrusion 36 and a second protrusion 37 , which have the same shape and function as the first protrusion 31 and the second protrusion 32 of the first protrusion structure 2 or the first protrusion 34 and the second protrusion 35 of the second protrusion structure 5 .

[0095] like Fig.12 , Fig.13As shown, the first protrusion 36 is a protrusion protruding from the atmosphere side 23, and extends obliquely in the reverse direction from the sealed object side toward the atmosphere side. The cross-sectional shape of the first protrusion 36 is the same or substantially the same as the cross-sectional shape of the first protrusion 31 of the first protrusion structure 2 (see Figure 4 ). In addition, as an example, the first protrusion 36 is a protrusion on the bottom of the ship (see Figure 6 ). That is, the height of the first protrusion 36 is not constant as a whole, and increases from the inner end 36b toward the outer end 36a. In addition, the height of the first protrusion 36 as a protrusion on the bottom of the ship may increase from the inner end 36b toward the outer end 36a to a predetermined position, and decrease from the predetermined position. In addition, the first protrusion 36 may also be a parallel protrusion (refer to Figure 5 ). In addition, the inner end 36b and the outer end 36a of the first protrusion 36 are the end of the sealing object side and the end of the atmosphere side of the first protrusion 36, respectively. In addition, the height of the first protrusion 36 is the protrusion amount from the atmosphere side surface 23, which is the distance from the atmosphere side surface 23 in the direction orthogonal to the atmosphere side surface 23.

[0096] The second protrusion 37 is a protrusion extending obliquely in the direction opposite to the first protrusion 36, and has, for example, the same or substantially the same shape and size as the first protrusion 36. Fig.12 , Fig.13 As shown, the second protrusion 37 is a protrusion protruding from the atmosphere side 23, and extends obliquely from the sealed object side toward the atmosphere side in the normal rotation direction. The cross-sectional shape of the second protrusion 37 is the same or substantially the same as the cross-sectional shape of the second protrusion 32 of the first protrusion structure 2 (refer to Figure 4 ). In addition, as an example, the second protrusion 37 is a protrusion on the bottom of the ship (see Figure 6 ). That is, the height of the second protrusion 37 is not constant as a whole, and increases from the inner end 37b toward the outer end 37a. In addition, the height of the second protrusion 37 as a protrusion on the bottom of the ship may increase from the inner end 37b toward the outer end 37a to a predetermined position, and decrease from the predetermined position. In addition, the second protrusion 37 may also be a parallel protrusion (refer to Figure 5 ). In addition, the inner end 37b and the outer end 37a of the second protrusion 37 are the end of the sealing object side and the end of the atmosphere side of the second protrusion 37, respectively. In addition, the height of the second protrusion 37 is the protrusion amount from the atmosphere side surface 23, which is the distance from the atmosphere side surface 23 in the direction orthogonal to the atmosphere side surface 23.

[0097] like Fig.12 , Fig.13 As shown, in the third protrusion structure 6, the outer end 36a of the first protrusion 36 is connected to the outer end 37a of the second protrusion 37. That is, the outer end 36a of the first protrusion 36 overlaps the outer end 37a of the second protrusion 37. In this way, the protrusion structure 3 is a V-shaped protrusion.

[0098] The inner end 36b of the first protrusion 36 and the inner end 37b of the second protrusion 37, which are the ends on the sealing object side of the third protrusion structure 6, are arranged on the atmosphere side in the axis x direction compared with the inner end 34b of the first protrusion 34 and the inner end 35b of the second protrusion 35 of the second protrusion structure 5. Fig.13 As shown, the inner end 36b of the first protrusion 36 and the inner end 37b of the second protrusion 37 of the third protrusion structure 6 are located on the atmosphere side in the axis x direction compared with the inner end 34b of the first protrusion 34 and the inner end 35b of the second protrusion 35 of the second protrusion structure 5, and are located on the sealing object side in the axis x direction compared with the outer end 34a of the first protrusion 34 and the outer end 35a of the second protrusion 35 of the second protrusion structure 5. In addition, the inner end 36b of the first protrusion 36 and the inner end 37b of the second protrusion 37 of the third protrusion structure 6 may also be located on the atmosphere side in the axis x direction compared with the outer end 34a of the first protrusion 34 and the outer end 35a of the second protrusion 35 of the second protrusion structure 5. In addition, as Fig.12 , Fig.13 As shown, the plurality of third protrusion structures 6 may be arranged so as to overlap with the plurality of first protrusion structures 2 when viewed in the axis x direction.

[0099] As described above, the third protrusion structure 6 is located on the atmospheric side in the axis x direction compared to the second protrusion structure 5, and the atmospheric side surface 23 of the lip tip portion 22 is expanded toward the atmospheric side in the axis x direction. Fig.13 As shown, the height of the first protrusion 36 and the height of the second protrusion 37 of the third protrusion structure 6 are greater than the height of the first protrusion 34 and the height of the second protrusion 35 of the second protrusion structure 5, so that when the front end portion 22 of the lip is worn and the contact surface S overlaps with multiple third protrusion structures 6, the first protrusion 36 and the second protrusion 37 have a width in the direction of the axis x and contact the outer peripheral surface 50a of the rotating shaft 50.

[0100] As described above, the sealing device 4 has a plurality of protrusion structures 2, 5, and 6, and the first protrusion structure 2, the second protrusion structure 5, and the third protrusion structure 6 each function in the same manner as the protrusion structure 2 of the sealing device 1 described above as the wear of the lip tip portion 22 progresses. That is, even if the wear of the lip tip portion 22 progresses and the first protrusion structure 2 disappears partially or entirely, the second protrusion structure 5 still functions, and even if the wear of the lip tip portion 22 progresses and the second protrusion structure 5 disappears partially or entirely, the third protrusion structure 6 still functions. Therefore, even if the wear of the lip tip portion 22 progresses, for example, even if the rotating shaft 50 rotates at a high speed in the forward and reverse directions at a circumferential speed of 50 m / s, the sealing device 4 can suppress or prevent oil leakage.

[0101] As described above, the sealing device 4 according to the second embodiment of the present invention can suppress leakage of the sealed object even when used for the rotating shaft 50 that rotates at high speed in both the forward rotation direction and the reverse rotation direction.

[0102] In addition, the sealing device 4 may not have the third protrusion structure 6. In addition, the sealing device 4 may have a plurality of protrusion structure rows of four or more rows repeatedly on the atmosphere side, like the first protrusion structure 2, the second protrusion structure 5, and the third protrusion structure 6.

[0103] Next, a driving system to which the sealing device according to the present invention is applied will be described. Fig.14 1 is a schematic diagram showing an example of a drive system to which the sealing device of the present invention is applicable. Fig.14 As shown, a drive system 100 as an example includes a rotating device such as a motor 101 as a driving force source, and a transmission 102 that changes the speed of the rotation transmitted from the driving force source side and outputs it, and the above-mentioned sealing device 1 or sealing device 4 is installed on the rotating shaft of such motor 101 and transmission 102. The drive system 100 is, for example, a drive system in an electric vehicle.

[0104] like Fig.14 As shown, as a drive system 100, a drive system including a motor 101 as a driving force source and a motor shaft 103 as a power shaft as the above-mentioned rotating shaft 50 can be listed. In the drive system 100, a sealing device 1 or a sealing device 4 is installed in the shaft hole of the shell that becomes the frame of the motor 101, and the sealing device 1 or the sealing device 4 is in contact with the outer peripheral surface of the motor shaft 103. In addition, as the drive system 100, a drive system including a transmission 102 that changes the speed of the rotation transmitted from the driving force source side and outputs it, and including at least one of the input shaft 104 and the output shaft 106 of the transmission 102 as the above-mentioned rotating shaft 50 can be listed. In addition, a sealing device 1 or a sealing device 4 is installed in the shaft hole of the shell that becomes the frame of the transmission 102, and the sealing device 1 or the sealing device 4 is in contact with the outer peripheral surface of the input shaft 104 and / or the output shaft 106.

[0105] Oil 108 as a sealed object is sealed in the housings of the motor 101 and the transmission 102 , and the housings are kept liquid-tight by the sealing device 1 or the sealing device 4 provided in the shaft holes of the motor shaft 103 , the input shaft 104 , and the output shaft 106 .

[0106] In addition, Fig.14In the transmission 102 shown, the motor shaft 103 is connected to the input shaft 104 of the transmission 102, and the driving force generated by the motor 101 is transmitted to the transmission 102 via the motor shaft 103 and the input shaft 104. In addition, the transmission 102 also has an intermediate shaft 105 for changing the speed of the driving force transmitted from the input shaft 104, and the input shaft 104, the intermediate shaft 105 and the output shaft 106 drive the wheels 109 provided on the output shaft 106 via the gear 107.

[0107] The drive system to which the sealing device of the present invention is applicable is not limited to the drive system in electric vehicles, and may be, for example, the drive system in vehicles other than electric vehicles, or various drive systems in other rotating equipment other than vehicles. That is, the sealing device of the present invention can be applied to various drive systems that have a rotating shaft that can rotate forward and reverse and transmit a driving force through the rotating shaft.

[0108] The present invention has been described above by the above-mentioned embodiments, but the technical scope of the present invention is not limited to the scope described in the above-mentioned embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above-mentioned embodiments. According to the description of the claims, the method to which such changes or improvements are made is also included in the technical scope of the present invention.

[0109] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the interpretation of the present invention. In addition, the above-described embodiments do not limit the objects of use of the present invention, and the present invention can include all objects as the objects of use. The various components and their configurations, materials, conditions, shapes, and dimensions of the above-described embodiments are not limited to the illustrated contents and can be appropriately changed. For example, the present invention includes differences in the implementation of manufacturing tolerances, etc. In addition, within the scope of technical non-contradiction, the components shown in different embodiments can be partially replaced or combined with each other. In addition, the various structures can be appropriately and selectively combined to achieve at least a portion of the above-mentioned topics and effects.

Claims

1. A sealing device for a rotating shaft rotating in one direction and another direction, characterized in that include: a reinforcing ring, annular about the axis; and an elastic body portion which is annular around the axis, has a sealing lip, is mounted on the reinforcement ring, and is formed of an elastic body, The sealing lip has a lip front end portion, which is an annular portion protruding toward the axis. The lip front end portion has a sealing side surface and an atmosphere side surface connected via the lip front end, the sealing side surface is an annular surface on the sealing object side, and the atmosphere side surface is an annular surface on the atmosphere side. A plurality of protrusion structures are arranged circumferentially on the atmospheric side surface, The protrusion structure includes a first protrusion and a second protrusion adjacent to each other in the circumferential direction. The first protrusion is a protrusion for returning the sealed object leaking out when the rotating shaft rotates in the one direction to the sealed object side by a pumping action. The second protrusion is a protrusion for returning the sealed object leaking out when the rotating shaft rotates in the other direction to the sealed object side by a pumping action.

2. The sealing device according to claim 1, characterized in that: The first protrusion extends obliquely in another direction of the circumferential direction from the sealing object side toward the atmosphere side, The second protrusion extends obliquely in one direction of the circumferential direction from the sealing object side toward the atmosphere side.

3. The sealing device according to claim 1, characterized in that: An end portion of the first protrusion on the atmosphere side in the protrusion structure is connected to an end portion of the second protrusion on the atmosphere side.

4. The sealing device according to claim 1, characterized in that: A circumferential width between an end portion of the first protrusion on the atmosphere side and an end portion of the second protrusion on the atmosphere side in the protrusion structure is smaller than a circumferential width between two protrusion structures adjacent to each other in the circumferential direction.

5. The sealing device according to claim 3, characterized in that: The circumferential width between the end of the first protrusion on the atmosphere side and the end of the second protrusion on the atmosphere side in the protrusion structure is a width that enables a flow path to be formed between the first protrusion and the second protrusion to return the sealed object to the sealed object side when the rotating shaft rotates.

6. The sealing device according to claim 1, characterized in that: In the protrusion structure, the first protrusion and the second protrusion extend from the front end of the lip toward the atmosphere side.

7. The sealing device according to claim 1, characterized in that: The plurality of protrusion structures include a plurality of first protrusion structures and a plurality of second protrusion structures, The multiple second protrusion structures are arranged so that the ends of the multiple second protrusion structures on the sealing object side are closer to the atmosphere side in the direction of the axis than the ends of the multiple first protrusion structures on the sealing object side, and are respectively arranged in the circumferential direction between the first protrusion structures adjacent to each other in the multiple first protrusion structures.

8. The sealing device according to claim 7, characterized in that: A height of the first protrusion and the second protrusion of the second protrusion structure from the atmospheric side surface is greater than a height of the first protrusion and the second protrusion of the first protrusion structure from the atmospheric side surface.

9. The sealing device according to claim 7, characterized in that: The plurality of protrusion structures include a plurality of third protrusion structures, The plurality of third protrusion structures are arranged so that the ends of the plurality of third protrusion structures on the sealing object side are closer to the atmosphere side in the direction of the axis than the ends of the plurality of second protrusion structures on the sealing object side, and are respectively arranged in the circumferential direction between the second protrusion structures adjacent to each other in the plurality of second protrusion structures.

10. The sealing device according to claim 9, characterized in that: A height of the first protrusion and the second protrusion of the third protrusion structure from the atmospheric side surface is greater than a height of the first protrusion and the second protrusion of the second protrusion structure from the atmospheric side surface.

11. The sealing device according to claim 1, characterized in that: The protrusion structure includes a third protrusion extending obliquely in another direction of the circumferential direction from the sealing object side toward the atmosphere side, The third protrusion is connected to the end of the first protrusion on the atmosphere side.

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