Sealing device

Abstract

To provide a sealing device having a structure capable of preventing rust from occurring on a component due to slurry or the like.SOLUTION: A sealing device 100 is arranged in a gap between an inner peripheral surface of a first member and an outer surface of a second member to seal the gap, and comprises an annular body part 10, a labyrinth slip 40, and one or more side lips 50. The sealing device 100 has a water-repellent part 20 formed on a portion of an outer surface of the sealing device 100. When the side lip 50 located most radially outward is referred to as a first side lip 51, the water-repellent part 20 is formed on at least a radially outside surface of the first side lip 51, and is not formed on the inside of the first side lip 51 in the sealing device 100.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a sealing device. [Background technology]

[0002] 2. Description of the Related Art A sealing device that prevents muddy water or the like from entering the inside of a bearing or the like of a vehicle is described in, for example, Patent Document 1. The sealing device described in Patent Document 1 comprises a labyrinth slip (dust lip in the same document) extending in the axial direction, a first side lip and a second side lip which are arranged radially inward from the labyrinth slip and each extend in the axial direction, and a grease lip which extends radially inward. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-119004 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, according to the investigations of the present inventors, there is room for improvement in the sealing device of Patent Document 1 in terms of preventing the generation of rust on the components due to muddy water or the like.

[0005] The present invention has been made in consideration of the above problems, and provides a sealing device having a structure capable of suppressing the occurrence of rust on parts due to muddy water, etc. [Means for solving the problem]

[0006] According to the present invention, there is provided a sealing device that is disposed in a gap between an inner circumferential surface of a first member and an outer surface of a second member and seals the gap, comprising: An annular body portion; a labyrinth slip extending from an outer periphery of the main body in a first axial direction; one or more side lips disposed radially inward from the labyrinth slip and extending from the main body in the first direction and abutting the outer surface of the second member; Equipped with A water-repellent portion is formed on a part of an outer surface of the sealing device, Among the one or more side lips, the side lip located radially outward is referred to as a first side lip, The water-repellent portion is formed on at least a radially outer surface of the first side lip, and is not formed on an inner side of the first side lip in the sealing device. Effect of the Invention

[0007] According to the present invention, it is possible to provide a sealing device having a structure capable of suppressing the occurrence of rust on components due to muddy water or the like. [Brief description of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view taken along a central axis of a sealing device according to a first embodiment. [Diagram 2] FIG. 2 is a partially enlarged view of FIG. [Diagram 3] 3A to 3C are schematic diagrams illustrating examples of the arrangement of protrusions in the first embodiment. [Figure 4] 1 is a cross-sectional view showing an example of a mounting structure for a sealing device according to a first embodiment. [Diagram 5] FIG. 6 is a cross-sectional view of a sealing device according to a second embodiment. [Figure 6] FIG. 11 is a schematic diagram for explaining another example of the arrangement of protrusions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0010] [First embodiment] First, the first embodiment will be described with reference to FIGS. The sealing device 100 according to this embodiment is disposed in a gap 250 between an inner circumferential surface 210a of a first member 210 and an outer surface 220a of a second member 220 to seal the gap 250. The sealing device 100 comprises an annular main body 10, a labyrinth slip 40 extending from an outer periphery of the main body 10 in a first axial direction AX1, and one or more side lips 50 arranged radially inward from the labyrinth slip 40, extending from the main body 10 in the first direction AX1, and abutting an outer surface 220a of the second member 220. The sealing device 100 has a water-repellent portion 20 formed on a portion of the outer surface of the sealing device 100 . Here, of the one or more side lips 50, the side lip 50 located outermost in the radial direction is referred to as a first side lip 51. The water-repellent portion 20 is formed at least on the radially outer surface (outer surface 51a) of the first side lip 51, and is not formed on the inner side of the first side lip 51 of the sealing device 100.

[0011] According to this embodiment, the sealing device 100 has the water-repellent portion 20 formed on a part of the outer surface of the sealing device 100, and therefore it is possible to suppress adhesion of muddy water and the like to the portion where the water-repellent portion 20 is formed. Therefore, it is possible to improve the rust prevention properties of the first member 210 and the second member 220 to which the sealing device 100 is attached and the sealing device 100. This makes it possible to reduce wear of each lip portion (the side lip 50 and the grease lip 30 described later) of the sealing device 100. Furthermore, the water-repellent portion 20 is formed on at least the radially outer surface (outer surface 51a) of the first side lip 51, and is not formed inside the first side lip 51 in the sealing device 100, so that a structure can be achieved in which the water-repellent portion 20 is applied only to necessary locations, thereby reducing the amount of water-repellent portion 20 used.

[0012] In the present invention, the sealing device 100 can be used, for example, as a hub bearing seal for vehicles such as automobiles, an industrial bearing seal, or a bearing seal for construction equipment or the like. In this embodiment, the sealing device 100 is a hub bearing seal for a vehicle, and is provided in a gap 250 between a first member 210 which is the outer race (outer ring) of the bearing, and a second member 220 which is the inner race (inner ring) of the bearing, as described later with reference to Figure 4.

[0013] This will be explained in more detail below. In the following explanation, unless otherwise specified, the explanation of the shape of each part of the sealing device 100 and the explanation of the positional relationship between each part of the sealing device 100 are assumed to be explanations of the sealing device 100 in its natural state when no external force is acting on it. In the following description, a direction perpendicular to the central axis AX0 of the sealing device 100 is referred to as a radial direction. In the radial direction, a direction away from the central axis AX0 is referred to as a radially outer direction, and a direction approaching the central axis AX0 is referred to as a radially inner direction. Moreover, the direction going around the central axis AX0 is referred to as the circumferential direction. In addition, among directions along the central axis AX0, one side (the right side in Figs. 1 and 2) based on the sealing device 100 is referred to as a first direction AX1. The first direction AX1 is the outside side of the sealing device 100 (the atmosphere side). Further, among the directions along the central axis AX0, the other side (the left side in Figs. 1 and 2) with respect to the sealing device 100 is referred to as a second direction AX2. The second direction AX2 is the inner side of the sealing device 100 (the interior side).

[0014] As described above, the sealing device 100 comprises an annular main body portion 10, a labyrinth slip 40 extending from an outer circumferential portion 11 of the main body portion 10 in a first direction AX1, and one or more side lips 50 arranged radially inward from the labyrinth slip 40 and extending from the main body portion 10 in the first direction AX1. In this embodiment, the sealing device 100 has two side lips 50, namely, a first side lip 51 and a second side lip 52. That is, the sealing device 100 has the second side lip 52 located radially inward of the first side lip 51. Additionally, the sealing device 100 includes a grease lip 30 extending radially inward from the body portion 10 .

[0015] As shown in FIG. 2, the main body 10 has, for example, a flange-shaped flange portion 12, a cylindrical portion 13, and an inner peripheral portion 14 which is the innermost peripheral portion of the main body 10. The flange portion 12 is formed, for example, in a plate shape that is substantially perpendicular to the central axis AX0. A labyrinth slip 40 extends from the outer circumferential end of the flange portion 12 in the first direction AX1. The cylindrical portion 13 is disposed coaxially with the central axis AX0, and extends from the inner peripheral end of the flange portion 12 in the second direction AX2. The inner peripheral portion 14 extends radially inward from the inner peripheral end portion of the flange portion 12 (the end portion of the cylindrical portion 13 on the first direction AX1 side). The grease lip 30 extends further radially inward from the radially inner end of the inner circumferential portion 14. More specifically, the grease lip 30 extends obliquely in a direction having a component of the second direction AX2, for example. The second side lip 52 extends from a radially inner end of the inner circumferential portion 14 in the first direction AX1. The first side lip 51 extends in the first direction AX1 from a radially intermediate portion of the inner circumferential portion 14. More specifically, the first side lip 51 extends obliquely in a direction having a radially outward component, for example. Also, the tip of the first side lip 51 is located closer to the first direction AX1 than the tip of the second side lip 52. In addition, the tip of the labyrinth lip 40 is located, for example, further on the first direction AX1 side than the tip of the first side lip 51. The main body 10 is formed into a three-dimensional shape that corresponds to the movement trajectory of the cut end surface shape of the main body 10 shown on one side (e.g., the upper side) of the central axis AX0 in Figure 1 when the cut end surface shape is rotated once around the central axis AX0.

[0016] The sealing device 100 includes, for example, a seal body component 60 and a reinforcing ring 70, which will be described below.

[0017] The seal body component 60 is made of an elastic body. The seal body component 60 is, for example, integrally molded as a whole, and includes the main body 10, the labyrinth slip 40, the first side lip 51, the second side lip 52, and the grease lip 30. The seal body constituent member 60 is formed in a three-dimensional shape that corresponds to the movement trajectory of the cut end surface shape of the seal body constituent member 60 shown on one side (e.g., the upper side) of the central axis AX0 in Figure 1 when the cut end surface shape is rotated once around the central axis AX0. Therefore, the labyrinth slip 40 is formed into a three-dimensional shape that corresponds to the movement trajectory of the cut end surface shape of the labyrinth slip 40 shown on one side (e.g., the upper side) of the central axis AX0 in Figure 1 when the cut end surface shape is rotated once around the central axis AX0. Similarly, each side lip 50 (first side lip 51, second side lip 52) is formed into a three-dimensional shape that corresponds to the movement trajectory of the cut end surface shape of each side lip 50 shown on one side (e.g., the upper side) of the central axis AX0 in Figure 1 when the cut end surface shape is rotated once around the central axis AX0. Similarly, the grease lip 30 is formed into a three-dimensional shape that corresponds to the movement trajectory of the cut end surface shape of the grease lip 30 shown on one side (e.g., the upper side) of the central axis AX0 in Figure 1 when the cut end surface shape is rotated once around the central axis AX0.

[0018] The elastic body constituting the seal body constituent member 60 is made of a highly elastic material (rubber-like elastic body) such as rubber (synthetic rubber or natural rubber) or a thermoplastic elastomer (thermoplastic resin rubber elastic body), and has flexibility. Examples of materials for the seal body constituent member 60 include rubber materials such as nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), fluororubber (FKM), and ethylene propylene diene rubber (EPDM). The seal body component 60 is integrally formed with the reinforcing ring 70 . For example, the reinforcing ring 70 is placed in a mold (not shown), an uncrosslinked rubber material is injected, and then the inside of the mold cavity is heated and pressurized to crosslink the rubber material, thereby forming the seal body component 60 by insert molding using the reinforcing ring 70 as an insert item. This insert molding results in the seal body component 60 being joined to the reinforcing ring 70 by vulcanization adhesion.

[0019] From the viewpoint of satisfying required characteristics such as rigidity, the reinforcing ring 70 is made of a material having a higher Young's modulus than the material constituting the seal body constituent member 60. The reinforcing ring 70 is made of, for example, a metal material or a resin material. The reinforcing ring 70 has, for example, a flange-shaped flange portion 71 that constitutes the outermost peripheral portion of the reinforcing ring 70, an outer cylindrical portion 72 that extends from a radially inner end of the flange portion 71 toward the second direction AX2, an inner cylindrical portion 74 that is folded back toward the first direction AX1 from a fold-back portion 73 that is the end of the outer cylindrical portion 72 on the second direction AX2 side, and an inner peripheral portion 75 that extends radially inward from the end of the inner cylindrical portion 74 on the first direction AX1 side. The flange portion 71 is formed in a plate shape perpendicular to the central axis AX0. The outer cylindrical portion 72 and the inner cylindrical portion 74 are disposed coaxially with the central axis AX0. The inner peripheral portion 75 is the innermost portion of the reinforcing ring 70 . A portion of the reinforcing ring 70 is embedded in the seal body constituent member 60. For example, most of the flange portion 71 (a portion excluding the radially inner end of the flange portion 71) and the radially inner end of the inner periphery 75 are embedded in the seal body constituent member 60. The cylindrical portion 13 of the main body 10 is filled between the outer cylindrical portion 72 and the inner cylindrical portion 74 . The reinforcing ring 70 is formed in a three-dimensional shape that corresponds to the movement trajectory of the cut end surface shape of the reinforcing ring 70 shown on one side (e.g., the upper side) of the central axis AX0 in Figure 1 when the cut end surface shape is rotated once around the central axis AX0.

[0020] When the reinforcing ring 70 is made of a metal material, examples of the material of the reinforcing ring 70 include stainless steel (SUS) or cold rolled steel (SPCC). When the reinforcing ring 70 is made of a metal material, the reinforcing ring 70 is produced by, for example, pressing or forging.

[0021] When the reinforcing ring 70 is made of a resin material, examples of the material of the reinforcing ring 70 include polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), etc. This resin material may contain, as necessary, a fiber base material such as glass fiber, organic fiber, metal fiber, carbon fiber, or mineral fiber, or may contain a particulate filler made of a metal oxide such as alumina, a metal hydroxide such as aluminum hydroxide, or a nitride such as boron nitride. When the reinforcing ring 70 is made of a resin material, the reinforcing ring 70 is manufactured by, for example, injection molding.

[0022] The water-repellent portion 20 is a water-repellent coating, and may be, for example, a water-repellent coat applied to the surface of the sealing device 100, or may be provided by attaching a pre-formed water-repellent sheet to the surface of the sealing device 100. Examples of materials for the water-repellent portion 20 include fluororesins. Examples of fluororesins include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkylvinylether copolymer (PFA), and tetrafluoroethylene-ethylene copolymer (ETFE). The water-repellent portion 20 is not limited to a fluororesin, and may be another water-repellent coating (for example, a coating of a hydrophobic silica compound).

[0023] As described above, the water-repellent portion 20 is formed at least on the radially outer surface (outer surface 51a) of the first side lip 51, and is not formed on the inner side of the first side lip 51 of the sealing device 100. In this embodiment, more specifically, the water-repellent portion 20 is continuously formed over the tip surface 51b of the first side lip 51, the outer surface 51a of the first side lip 51, the entire surface of the main body 10 facing the first direction AX1 at a portion radially outer than the base end of the first side lip 51, the radially inner surface (inner surface 40a) of the labyrinth slip 40, the tip surface of the labyrinth slip 40, and the radially outer surface of the labyrinth slip 40. That is, in the case of this embodiment, the water-repellent portion 20 is formed from the tip surface 51b of the first side lip 51 to almost the entire area of ​​the outer circumferential portion of the seal body constituent member 60. However, in the surface of the flange portion 12 of the main body 10 on the second direction AX2 side, the water-repellent portion 20 may not be formed in the portion below the outer circumferential portion 11, as shown in FIG.

[0024] Here, at least a part of the region inside the first side lip 51 of the sealing device 100 is a grease application region in which grease 80 is applied to the outer surface. In other words, as described above, the water-repellent portion 20 is not formed in the grease application area since the water-repellent portion 20 is not formed in the grease application area and at least a portion of the area inward of the first side lip 51 in the sealing device 100 is the grease application area. This improves the adhesion of the grease 80 to the grease application area, making it difficult for the grease 80 to fall off. If the water-repellent portion 20 were also formed in the grease application area, the adhesion of the grease 80 would be poor, making it easier for the grease 80 to fall off.

[0025] More specifically, in this embodiment, the radially inner surface (inner surface 51c) of the first side lip 51 is applied with a first grease 81, and the portion extending from the radially inner surface (inner surface 30a) of the grease lip 30 to the radially inner surface (inner surface 52a) of the second side lip 52 is applied with a second grease 82, and each forms a grease application area. When the grease 80 is not applied to the radially inner surface (inner surface 51c) of the first side lip 51, the water-repellent portion 20 may also be formed on the inner surface 51c.

[0026] Here, on the inner surface of the sealing device 100 in a portion radially outward from the first side lip 51, a protrusion or groove (in this embodiment, protrusion 90) extending in the axial direction is formed, and a water-repellent portion 20 is also formed on the surface of this protrusion or groove. Muddy water and the like may enter the inside of the sealing device 100 through the gap 240 (FIG. 4) between the labyrinth slip 40 and the second member 220, but by forming such a protrusion or groove, the muddy water and the like can be efficiently discharged to the outside by the shaking-off effect of the protrusion or groove when the sealing device 100 rotates. This makes it possible to reduce the length of time (exposure time) that each part of the sealing device 100 is exposed to muddy water and the like, and further improve the rust resistance of the sealing device 100.

[0027] More specifically, ridges or grooves are formed in the formation area of ​​the water-repellent portion 20, and the water-repellent portion 20 is also formed on the surface of the ridges or grooves. As an example, the ridges or grooves may be formed only on the inner surface 40a of the labyrinth slip 40, as shown in Fig. 2 etc. In this case, for example, the ridges or grooves may be formed from the end of the inner surface 40a on the first direction AX1 side to the end on the second direction AX2 side, as shown in Fig. 2. However, the ridges or grooves may be formed from the inner surface 40a to the flange portion 12 of the main body 10, or from the inner surface 40a to the flange portion 12 and the inner periphery 14 of the main body 10.

[0028] It is preferable that the sealing device 100 has a plurality of protrusions or grooves formed intermittently in the circumferential direction. The extending direction of the ridges or grooves may not include a circumferential component and may only include a directional component of the central axis AX0, or may include a directional component of the central axis AX0 and a radial component. However, it is more preferable that the extending direction of the ridges or grooves includes a circumferential component. In other words, it is preferable that a plurality of ridges or grooves are formed extending in a direction inclined with respect to the axial direction. By having the extending direction of the plurality of ridges or grooves inclined with respect to the axial direction (the extending direction of the ridges or grooves includes a circumferential component), muddy water and the like can be efficiently discharged to the outside by a pumping action. In particular, it is preferable that the protrusions or grooves whose inclination directions are opposite to each other are alternately arranged in the circumferential direction. In this way, a flow of muddy water or the like entering the inside of the sealing device 100 through the gap 240 and a flow of the muddy water or the like exiting the sealing device 100 can be formed, and the inside of the sealing device 100 can be prevented from becoming negative pressure. In addition, whether the rotation direction of the sealing device 100 is forward or reverse, the muddy water or the like can be effectively discharged from the inside of the sealing device 100.

[0029] Here, "protrusions or grooves having opposite inclination directions alternately arranged in the circumferential direction" may mean that protrusions or grooves having opposite inclination directions are arranged one by one alternately in the circumferential direction, but typically means that multiple (e.g., four) protrusions or grooves have the same inclination direction, and the next multiple (e.g., four) have the opposite inclination direction, alternately arranged.

[0030] Fig. 3 is a schematic diagram for explaining an example of the arrangement of the ridges 90 in this embodiment. Fig. 3 shows a schematic arrangement of the ridges 90 when the inner surface 40a of the labyrinth slip 40 is viewed in the direction of the arrow A shown in Fig. 1. In the example of Fig. 3, four first ridges 91, which are ridges 90 on one side, and four second ridges 92, which are ridges 90 on the other side, are alternately arranged six times. The first ridges 91 and the second ridges 92 have the same shape and dimensions, but differ in inclination direction. The total number of the first ridges 91 and the total number of the second ridges 92 in the sealing device 100 are equal to each other.

[0031] FIG. 6 is a schematic diagram illustrating examples of the inclination angle of the ridges 90 (first ridges 91 and second ridges 92) and the intervals between the ridges 90. In FIG. In FIG. 6, an orthogonal plane OP is an imaginary plane perpendicular to the central axis AX0. The inclination angle θ1 of the first ridges 91 and the inclination angle θ2 of the second ridges 92 with respect to the orthogonal plane OP may each be, for example, 20 degrees or more and 40 degrees or less, and more preferably about 30 degrees. The distance L1 between adjacent first ridges 91 and the distance L2 between adjacent second ridges 92 may each be, for example, 0.5 mm or more and 0.9 mm or less. Setting the inclination angles of the ridges 90 and the distances between the ridges 90 in this manner allows muddy water and the like to be more effectively discharged from inside the sealing device 100. When grooves are used instead of the ridges 90, the grooves may be arranged in the same manner as the ridges 90 described with reference to FIGS.

[0032] Here, the water-repellent portion 20 is preferably formed in a region into which muddy water penetrates when the sealing device 100 rotates around the axis at 300 rpm or more and 700 rpm or less (that is, in the medium to low speed range). At high speeds (for example, around 1100 rpm), muddy water and the like can be repelled by centrifugal force without relying on the action of the water-repellent portion 20 or the protrusions or grooves, but compared to the high speed range, at medium and low speeds, muddy water and the like are more likely to remain inside the sealing device 100. In contrast, by forming the sealing device 100 in an area into which muddy water enters when the sealing device 100 rotates around the axis at 300 rpm or more and 700 rpm or less, the action of the water-repellent portion 20 can improve the discharge of muddy water, etc.

[0033] Here, after the sealing device 100 is exposed to water and rotated at a rotation speed of 300 rpm or more and 700 rpm or less for 60 seconds or more, the area in which the water-repellent portion 20 is formed is 2 It is preferable that the amount of residual water per unit is 0.1 ml or less. Here, the term "subjecting the sealing device 100 to water" means that the sealing device 100 is immersed in water. In a test for determining the amount of remaining water, the lower half of the sealing device 100 is rotated while immersed in water for a certain period of time (60 seconds or more and 24 hours or less), and then the sealing device 100 is rotated in a dry state after draining the water from the sealing device 100 for a certain period of time (60 seconds or more and 4 hours or less), and then the area where the water-repellent portion 20 is formed is covered with 100 cm 2 At this time, the sealing device 100 is rotated with the central axis AX0 of the sealing device 100 horizontal or eccentric (including eccentricity during a miso grinding motion). In addition, it is preferable to use muddy water as the water in this test, but instead of muddy water, various liquids that are applied to the vehicle hub, such as salt water, muddy salt water, etc., may be used.

[0034] The sealing device 100 is configured as described above, and is attached, for example, as described below. As shown in FIG. 4, a ball 230 is arranged inside the bearing, and a sealing device 100 is arranged in a gap 250 between a first member 210 (outer race) and a second member 220 (inner race) between the arrangement area of ​​the ball 230 and the outside of the bearing. The outer surface 220a of the second member 220 on which the sealing device 100 is arranged is curved, for example, in an arc-shaped cross section, and includes a portion facing the inner surface 210a of the first member 210 through a part of the gap 250, and a portion facing the end face 210b of the first member 210 through another part of the gap 250. The end surface 210b is a surface that intersects (for example, is perpendicular to) the inner circumferential surface 210a, and intersects (for example, is perpendicular to) the central axis AX0 of the sealing device 100 (FIG. 1).

[0035] The L-shaped cross-section of the main body 10 of the sealing device 100 abuts against a portion of the first member 210 from the inner peripheral surface 210a to the end surface 210b. The grease lip 30 is pressed against a portion of the outer surface 220a facing the inner peripheral surface 210a. The second side lip 52 and the first side lip 51 are pressed against a portion of the outer surface 220a between a portion facing the inner peripheral surface 210a and a portion facing the end surface 210b. The tip of the labyrinth lip 40 is disposed near a portion of the outer surface 220a facing the end surface 210b. In this manner, the sealing device 100 is fixed to the first member 210 . When the first member 210 and the second member 220 rotate relatively around the axis, the sealing device 100 rotates integrally with the first member 210, and the first side lip 51, the second side lip 52 and the grease lip 30 slide against the outer surface 220a. A gap 240 exists between the tip of the labyrinth slip 40 and the outer surface 220a, and this gap 240 allows muddy water, etc. to penetrate into the inside of the sealing device 100 (the area up to the outer surface 51a and the vicinity of the tip surface 51b of the first side lip 51). Normally, the sealing function of the first side lip 51 prevents muddy water and the like from entering the inside of the first side lip 51 .

[0036] In the case of this embodiment, by forming the above-mentioned water-repellent portion 20 and the above-mentioned protrusions or grooves (e.g., protrusions 90), muddy water and the like that has infiltrated into the interior of the sealing device 100 can be smoothly discharged to the outside, thereby achieving good rust resistance of the sealing device 100.

[0037] Second Embodiment Next, a second embodiment will be described with reference to FIG. The sealing device 100 of this embodiment differs from the sealing device 100 of the first embodiment described above in the points described below, but in other respects is configured in the same manner as the sealing device 100 of the first embodiment described above.

[0038] In this embodiment, the second member 220 includes an axis member 260 that is disposed coaxially with the central axis of the sealing device 100, and a slinger 110 that is fixed to the axis member 260.

[0039] The slinger 110 is formed, for example, in an L-shaped cross section having a cylindrical portion 112 fixed along the outer circumferential surface of the shaft member 260, and a flange-shaped flange portion 111 extending radially outward from an end portion of the cylindrical portion 112 on the first direction AX1 side. The slinger 110 is formed in a three-dimensional shape corresponding to the movement trajectory of the cut end surface shape of the slinger 110 shown in FIG. 5 when the cut end surface shape is rotated once around the central axis of the sealing device 100. The flange portion 111 is disposed so as to be perpendicular to the central axis of the sealing device 100 .

[0040] In this embodiment, the extension lengths of the first side lip 51 and the second side lip 52 are equal to each other, and the tip end of the first side lip 51 and the tip end of the second side lip 52 are each pressed against the inner surface 111a (the surface facing the second direction AX2) of the flange portion 111 of the slinger 110. The tip end of the grease lip 30 is pressed against an inner surface 112 a (surface facing radially outward) of the cylindrical portion 112 of the slinger 110 . Moreover, a portion of the sealing device 100 including the labyrinth slip 40 and the cylindrical portion 76 is fixed along the inner circumferential surface 210 a of the first member 210 . Further, a gap 240 is formed between the inner surface 40a of the labyrinth slip 40 and the end surface 111b (the radially outer end surface) of the flange portion 111 of the slinger 110. It should be noted that the main body 10 does not have, for example, the cylindrical portion 13 (FIG. 2). In addition, the reinforcing ring 70 is composed of, for example, a cylindrical tubular portion 76 arranged along the labyrinth slip 40, an inner flange portion 77 having an inner flange shape extending radially inward from the AX2 side end of the cylindrical portion 76, and an inner circumferential portion 78 extending further radially inward from the radially inner end of the inner flange portion 77.

[0041] In this embodiment, since the slinger 110 is fixed to the shaft member 260, when the sealing device 100 rotates around an axis relative to the second member 220 (slinger 110 and shaft member 260) together with the first member 210, the first side lip 51 and the second side lip 52 slide against the inner surface 111a of the flange portion 111 of the slinger 110, and the grease lip 30 slides against the inner surface 112a of the tubular portion 112 of the slinger 110.

[0042] In this embodiment, the water-repellent portion 20 is formed not only on the outer surface of the seal body constituent member 60 but also on the outer surface of the slinger 110 . That is, the water-repellent portion 20 is formed continuously over the end face 111b, inner surface 111a, inner surface 112a, and end face 112b (the end face on the second direction AX2 side) of the tubular portion 112 of the slinger 110.

[0043] In this embodiment, the ridges or grooves (for example, the ridges 90) are disposed on the inner surface 40a of the labyrinth slip 40, inside the gap 240 and in the vicinity of the gap 240. In the present embodiment as well, a plurality of ridges or grooves are formed extending in a direction inclined relative to the axial direction, and the ridges or grooves inclined in opposite directions are alternately arranged in the circumferential direction.

[0044] In the case of this embodiment as well, by forming the water-repellent portion 20 and the protrusions or grooves (e.g., the protrusions 90), muddy water and the like that has infiltrated into the sealing device 100 can be smoothly discharged to the outside, thereby achieving good rust resistance of the sealing device 100.

[0045] In this embodiment, the sealing device 100 may be distributed alone, or may be distributed as a set of the sealing device 100 and the slinger 110. Of the structures shown in Fig. 5, those including the sealing device 100 and the slinger 110 will be referred to as a sealing structure.

[0046] Although the embodiment has been described above with reference to the drawings, this is merely an example of the present invention, and various configurations other than those described above can also be adopted.

[0047] The present embodiment encompasses the following technical ideas. (1) A sealing device disposed in a gap between an inner circumferential surface of a first member and an outer surface of a second member to seal the gap, An annular body portion; a labyrinth slip extending from an outer periphery of the main body in a first axial direction; one or more side lips disposed radially inward from the labyrinth slip and extending from the main body in the first direction and abutting the outer surface of the second member; Equipped with A water-repellent portion is formed on a part of an outer surface of the sealing device, Among the one or more side lips, the side lip located radially outward is referred to as a first side lip, The water-repellent portion is formed on at least a radially outer surface of the first side lip, and is not formed on an inner side of the first side lip of the sealing device. (2) A grease lip is further provided, the grease lip extending radially inward from the main body portion and contacting the outer surface of the second member. The sealing device according to (1), wherein at least a portion of a region of the sealing device located inside the first side lip is a grease application region in which grease is applied to an outer surface. (3) The sealing device according to (1) or (2), further comprising a second side lip located radially inwardly of the first side lip. (4) A sealing device according to any one of (1) to (3), wherein the water-repellent portion is formed in an area into which muddy water penetrates when the sealing device rotates around an axis at 300 rpm or more and 700 rpm or less. (5) After the sealing device is exposed to water and rotated at a rotation speed of 300 rpm to 700 rpm for 60 seconds or more, the water repellent portion is 2 The sealing device according to (4), wherein the amount of residual water per unit time is 0.1 ml or less. (6) In the sealing device, a protrusion or a groove extending in an axial direction is formed on an inner circumferential surface of a portion radially outward from the first side lip, The sealing device according to any one of (1) to (5), wherein the water-repellent portion is also formed on the surface of the protrusion or groove. (7) A plurality of the protrusions or grooves are formed extending in a direction inclined relative to the axial direction, The sealing device according to (6), wherein the protrusions or grooves having inclination directions opposite to each other are alternately arranged in the circumferential direction. [Explanation of symbols]

[0048] 10 Main body 11 Outer periphery 12 Flange 13 Cylindrical part 14 Inner circumference 20 Water-repellent section 30 Grease Lip 30a Inside surface 40 Labyrinth Slip 40a Inner surface 50 Side lip 51 First side lip 51a External surface 51b Tip surface 51c Inside surface 52 Second side lip 52a Inner surface 60 Seal body components 70 Reinforcement Ring 71 Flange 72 Outer cylindrical part 73 Folded part 74 Inner cylindrical part 75 Inner circumference 76 Cylindrical section 77 Inner flange 78 Inner circumference 80 Grease 81 First Grease 82 Second Grease 90 protrusion 91 First protrusion 92 2nd protrusion 100 Sealing device 110 Slinger 111 Flange part 111a Inside surface 111b End face 112 Cylindrical part 112a Inside surface 112b End face 210 First member 210a Inner surface 210b End face 220 Second member 220a Exterior 230 Ball 240 Gap 250 gap 260 Shaft member

Claims

1. A sealing device disposed in a gap between an inner circumferential surface of a first member and an outer surface of a second member to seal the gap, An annular body portion; a labyrinth slip extending from an outer periphery of the main body in a first axial direction; one or more side lips disposed radially inward from the labyrinth slip and extending from the main body in the first direction and abutting the outer surface of the second member; Equipped with A water-repellent portion is formed on a part of an outer surface of the sealing device, Among the one or more side lips, the side lip located most radially outward is referred to as a first side lip. A sealing device, wherein the water-repellent portion is formed on at least a radially outer surface of the first side lip, and is not formed on an inner side of the first side lip in the sealing device.

2. a grease lip extending radially inward from the body and abutting the outer surface of the second member; The sealing device according to claim 1 , wherein at least a portion of the sealing device located inside the first side lip is a grease application area having an outer surface coated with grease.

3. The sealing device according to claim 1 or 2, further comprising a second side lip located radially inwardly of the first side lip.

4. 3. The sealing device according to claim 1, wherein the water-repellent portion is formed in an area into which muddy water enters when the sealing device rotates around an axis at a speed of 300 rpm or more and 700 rpm or less.

5. After the sealing device is exposed to water and rotated for 60 seconds or more at a rotation speed of 300 rpm or more and 700 rpm or less, the water repellent portion is formed in a region of 100 cm ２ 5. The sealing device according to claim 4, wherein the amount of residual water per unit time is 0.1 ml or less.

6. A protrusion or groove extending in an axial direction is formed on an inner circumferential surface of a portion of the sealing device radially outward from the first side lip, 3. The sealing device according to claim 1, wherein the water-repellent portion is also formed on the surface of the ridge or groove.

7. A plurality of the protrusions or grooves are formed extending in a direction inclined relative to the axial direction, 7. The sealing device according to claim 6, wherein the protrusions or grooves having inclination directions opposite to each other are arranged alternately in the circumferential direction.

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