Sealing device

Abstract

To suppress an increase in torque resistance by suppressing a decrease in sealing performance even when a diameter is increased.SOLUTION: The hub seal 1 includes a seal body 3 and a slinger 4. The seal body 3 includes a reinforcing ring 10 and an elastic body part 20 attached to the reinforcing ring 10. The slinger 4 includes a main body portion 30 and an elastic body portion 40 attached to the main body portion 30. The elastic body portion 20 of the seal main body 3 has a first labyrinth lip 21 and a second labyrinth lip 22 each extending toward an annular inner side. The elastic body portion 40 of the slinger 4 has a slinger labyrinth lip 41 extending outward. The second labyrinth lip 22 is positioned on the inner peripheral side of the first labyrinth lip 21, and the 41a of the tip end portion of the slinger labyrinth lip 41 is positioned between the first labyrinth lip 21 and the second labyrinth lip 22 in the radial direction so as to form a labyrinth seal.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] In vehicles, such as automobiles, hub bearings that support the wheels for free rotation have traditionally been fitted with hub seals, which are sealing devices, to seal the gap formed between the outer and inner rings. Hub seals seal in the lubricant inside the hub bearing and prevent foreign matter from entering the internal space. Because hub bearings are in harsh environments where they are directly exposed to foreign matter such as rainwater, muddy water, and dust, hub seals are required to have improved sealing performance against foreign matter.

[0003] Meanwhile, due to demands for lower fuel consumption and other factors, there is a demand for hub seals that reduce the sliding resistance (torque resistance) that the seal lips apply to the hub bearing. While increasing the number of seal lips would be one way to improve the sealing performance of the hub seal, this would increase the torque resistance of the hub seal. For this reason, various hub seals have been proposed that increase the number of seal lips to improve sealing performance against foreign matter without increasing the torque resistance of the hub seal (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-079615 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, hub seals are required to have improved sealing performance in harsh environments and reduced torque resistance. In recent years, due to structural changes in the objects to which hub seals are applied, there has been a demand for larger diameter hub seals. As the diameter of a hub seal increases, its circumferential length increases, which can lead to a decrease in sealing performance due to factors such as an increase in the circumferential speed of the shaft. Furthermore, an increase in the circumferential length of a hub seal increases torque resistance. Thus, new challenges have arisen for sealing devices used in devices such as hub bearings that are used in harsh environments with regard to the intrusion of liquid foreign matter. A configuration is required that does not decrease sealing performance or increase torque resistance even when the diameter is increased.

[0006] 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 that can suppress a decrease in sealing performance even when the diameter is increased, and can also suppress an increase in torque resistance. [Means for solving the problem]

[0007] In order to achieve the above object, the sealing device according to the present invention is a sealing device that seals a gap between an outer peripheral side member and an inner peripheral side member that are rotatable relative to each other about an axis and that is at least partially surrounded by the outer peripheral side member, and includes a sealing device main body that is fixed to the outer peripheral side member, and a slinger that is fixed to the inner peripheral side member, the sealing device main body including a reinforcing ring that is an annular member about the axis, and an elastic body portion that is attached to the reinforcing ring and is formed from an elastic body that is annular about the axis, and the slinger including a main body portion that is an annular member about the axis, and an elastic body portion that is attached to the main body portion and is formed from an elastic body that is annular about the axis. The elastic body portion of the sealing device main body each has a first labyrinth slip and a second labyrinth slip which are portions extending toward one side in the axial direction in an annular shape around the axis, and the elastic body portion of the slinger has a sling labyrinth slip which is a portion extending toward the other side in the axial direction in an annular shape around the axis, the second labyrinth slip is located more inward than the first labyrinth slip, and the tip end of the sling labyrinth slip is located between the first labyrinth slip and the second labyrinth slip in the radial direction to form a labyrinth seal.

[0008] In the sealing device according to one aspect of the present invention, the first labyrinth slip, the front second labyrinth slip, and the sling labyrinth slip overlap each other when viewed in the radial direction.

[0009] In a sealing device according to one aspect of the present invention, a recess is formed between the first labyrinth slip and the second labyrinth slip, the recess being an annular portion around the axis that is recessed toward the other side in the axial direction.

[0010] In a sealing device according to one aspect of the present invention, the sling rubber slip is inclined outwardly toward the other side in the axial direction.

[0011] In the sealing device according to one aspect of the present invention, the second labyrinth slip is inclined outwardly toward one side in the axial direction.

[0012] In a sealing device according to one aspect of the present invention, the sealing device body and the slinger face each other radially on the outer circumferential side of the first labyrinth slip, forming an annular gap around the axis.

[0013] In a sealing device according to one aspect of the present invention, the main body portion of the slinger has a flange portion which is a ring-shaped portion extending radially around the axis, and a fitting portion which is a cylindrical portion extending from the inner end of the flange portion along the axis toward the other side in the axial direction, and the elastic body portion of the sealing device main body has a ring-shaped radial lip around the axis formed to contact the fitting portion of the main body portion of the slinger.

[0014] In the sealing device according to one aspect of the present invention, the outer circumferential member rotates and the inner circumferential member is fixed. [Effects of the Invention]

[0015] According to the sealing device of the present invention, even if the diameter is increased, it is possible to suppress a decrease in sealing performance and also to suppress an increase in torque resistance. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 2 is a cross-sectional view showing a cross section taken along a plane including the axis of a hub bearing as an example. [Figure 2] 2 is a partially enlarged cross-sectional view of the vicinity of a hub seal as a sealing device according to an embodiment of the present invention in FIG. 1. FIG. [Figure 3] 4 is a cross-sectional view showing a cross section taken along a plane including the axis of the seal body of the hub seal. FIG. [Figure 4] 1 is a cross-sectional view of an example of an in-wheel motor unit as an example of an application of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that in the drawings, not all of the components are labeled with reference numerals, and some of the components may be omitted.

[0018] The sealing device according to the present invention is a sealing device that seals a gap between an outer peripheral member and an inner peripheral member that are rotatable relative to each other about an axis. The inner peripheral member is at least partially surrounded by the outer peripheral member. The sealing device according to the present invention is applied to, for example, a hub bearing. FIG. 1 is a cross-sectional view of an example hub bearing 100 taken along a plane including the axis. As shown in FIG. 1, the hub bearing 100 is a conventionally known hub bearing that is installed in a vehicle such as an automobile and rotatably supports a wheel in an axle or suspension system. The hub bearing 100 is, for example, an outer-ring rotating hub bearing in which the outer peripheral member rotates and the inner peripheral member is fixed. Note that the sealing device according to the present invention is not limited to a hub seal, and the application of the sealing device according to the present invention is not limited to hub bearings.

[0019] Specifically, as shown in FIG. 1 , the hub bearing 100 includes an annular outer ring 101 serving as an outer peripheral member and having a central axis or approximate central axis along axis x; an inner ring 102 serving as an inner peripheral member that is rotatable relative to the outer ring 101 and partially surrounded by the outer ring 101 and has a central axis or approximate central axis along axis x; and a plurality of bearing balls (rolling elements) 103 disposed between the outer ring 101 and the inner ring 102. The hub bearing 100 is an outer ring rotating type, and when the hub bearing 100 is in use and attached to a vehicle or the like, the inner ring 102 is fixed and the outer ring 101 is rotatable relative to the inner ring 102. Specifically, the inner ring 102 is a tubular or approximate cylindrical member extending along axis x. Specifically, the outer ring 101 has a tubular portion 101a and a wheel mounting flange 101b. The tubular portion 101a is a tubular or approximate cylindrical portion extending along axis x. The wheel mounting flange 101b is a portion that expands in a disk shape from the outer end of the cylindrical portion 101a toward the outer periphery, and is the portion to which a brake disc rotor and a tire wheel (not shown) are attached by a plurality of hub bolts 107. In the internal space S between the outer ring 101 and the inner ring 102, bearing balls 103 are held by a cage 104.

[0020] The cylindrical portion 101a of the outer ring 101 defines a through hole 105 extending in the direction of the axis x, and the inner ring 102 is inserted into this through hole 105, forming an annular internal space S extending along the axis x between the cylindrical portion 101a and the inner ring 102. As described above, the bearing balls 103 are housed within this internal space S and held by the cage 104, and a lubricant is applied or injected into the internal space S. A sealing device 1 is attached to the inner opening 101c of the outer ring 101, which forms an opening that opens the internal space S on the inside. Meanwhile, a sealing device 2 is attached to the outer opening 101d of the outer ring 101, which forms an opening that opens the internal space S on the outside.

[0021] The sealing device 1 is a sealing device according to a first embodiment of the present invention and is an inner hub seal. On the other hand, the sealing device 2 is a conventionally known hub seal and is an outer hub seal. The sealing devices 1 and 2 seal the internal space S, prevent the lubricant in the internal space S from leaking to the outside, and prevent foreign matter such as rainwater, muddy water, and dust from entering the internal space S from the outside. The sealing device 2 may be the sealing device according to the present invention. In this case, the sealing device 2 has the same configuration as the sealing device 1, but its specific form, such as its shape and size, corresponds to the portion of the hub bearing 100 to which the sealing device 2 is attached. Furthermore, the configuration of the hub bearing to which the sealing devices 1 and 2 are applied is not limited to the configuration of the hub bearing 100 described above. In the following description, a sealing device applied to a hub bearing is also referred to as a hub seal.

[0022] Next, we will explain the hub seal 1 according to the first embodiment of the present invention. Figure 2 is an enlarged cross-sectional view of a portion of the hub seal 1 and its vicinity in Figure 1. Figure 2 shows one side of the hub seal 1 relative to the axis x in a cross section taken along a plane including the axis x when the hub seal 1 is in use and attached to a hub bearing 100. When the hub seal 1 is in use, a seal main body 3 and a slinger 4, which will be described later, are attached to the hub bearing 100 so that they are in a predetermined relative position.

[0023] As shown in FIG. 2, the hub seal 1 includes a seal body 3, which is a sealing device body fixed to an outer ring 101, and a slinger 4, which is fixed to an inner ring 102. The seal body 3 includes a reinforcing ring 10, which is an annular member about the axis x, and an elastic body portion 20, which is attached to the reinforcing ring 10 and is formed of an annular elastic body about the axis x. The slinger 4 includes a main body portion 30, which is an annular member about the axis x, and an elastic body portion 40, which is attached to the main body portion 30 and is formed of an annular elastic body about the axis x. The elastic body portion 20 of the seal body 3 includes a first labyrinth slip 21 and a second labyrinth slip 22, which are portions extending inward (to one side) in the direction of the annular axis x around the axis x. The elastic body portion 40 of the slinger 4 includes a sling labyrinth slip 41, which is a portion extending outward (to the other side) in the direction of the annular axis x around the axis x. The second labyrinth slip 22 is located more inward than the first labyrinth slip 21, and the tip end 41a of the sling labyrinth slip 41 is located radially between the first labyrinth slip 21 and the second labyrinth slip 22 to form a labyrinth seal. The configuration of the hub seal 1 will be described in detail below.

[0024] As shown in FIGS. 1 and 2, the inner side refers to the side indicated by arrow a in the direction of axis x, while the outer side refers to the side indicated by arrow b in the direction of axis x. In a hub bearing 100 mounted on a vehicle, the inner side is the body side, and the outer side is the wheel side. The radial direction refers to the direction perpendicular to the axis x. The outer peripheral side refers to the side of the hub bearing 100 that is radially away from the axis x, which is the side indicated by arrow c in FIGS. 1 and 2. The inner peripheral side refers to the side of the hub bearing 100 that is radially closer to the axis x, which is the side indicated by arrow d in FIGS. 1 and 2. The axis x of the hub seal 1 mounted on the hub bearing 100 coincides or approximately coincides with the axis of the hub bearing 100. For ease of explanation, the axis of the hub bearing 100 is referred to as the axis x.

[0025] As shown in Fig. 2, for example, the reinforcing ring 10 of the seal body 3 is an annular, plate-shaped metal member whose central axis or approximate central axis is the axis x, and is formed to be press-fitted into a through-hole 105 of an outer ring 101 of a hub bearing 100. By press-fitting the reinforcing ring 10 into the outer ring 101, the seal body 3 is fixed to the outer ring 101. As shown in Fig. 2, for example, the reinforcing ring 10 has a cylindrical tubular portion 11 and a lip support portion 12 that bends inward from the outer end of the tubular portion 11 and extends radially inward.

[0026] FIG. 3 is a cross-sectional view of the seal body 3 taken along a plane including the axis x. Note that FIG. 3 shows only one side of the cross section of the seal body 3 relative to the axis x. As shown in FIGS. 2 and 3, the tubular portion 11 has, for example, a fitting portion 11a, which is an outer portion, and a gasket support portion 11b, which is an inner portion. The fitting portion 11a is, for example, a cylindrical or approximately cylindrical portion with the axis x as its central axis or approximately central axis. As shown in FIGS. 1 and 2, the tubular portion 11 is formed so that the outer peripheral surface 11c, which is the outer surface of the fitting portion 11a, is press-fitted into the inner opening 101c of the outer ring 101 and is fitted to its inner peripheral surface 101e. The gasket support portion 11b extends from the inner end of the fitting portion 11a via a step, and the outer peripheral surface 11d, which is the outer surface of the gasket support portion 11b, is located more inward than the outer peripheral surface 11c of the fitting portion 11a.

[0027] The lip support portion 12 is shaped so that, for example, the first labyrinth slip 21, the second labyrinth slip 22, and the side lip 23, radial lip 24, and grease lip 25 (described later) are positioned at desired positions relative to the slinger 4 in the hub seal 1. As shown in FIGS. 2 and 3 , the lip support portion 12 has a return portion 12a and a lip flange portion 12b. The return portion 12a is, for example, an annular plate-shaped portion that extends radially from the outer end of the tubular portion 11 and then bends inward and extends at an angle relative to the radial direction. The lip flange portion 12b is, for example, an annular plate-shaped portion that extends radially from the inner end of the return portion 12a. The reinforcing ring 10 is formed as an integral member, for example, by pressing or forging a metal plate. The tubular portion 11 and the lip support portion 12 are portions of the reinforcing ring 10 that are integrally formed from the same material and are continuous as a single unit. The metal material of the reinforcing ring 10 is, for example, stainless steel or SPCC (cold rolled steel).

[0028] As described above, the elastic body portion 20 is attached to the reinforcing ring 10 and is integral with the reinforcing ring 10 so as to cover the reinforcing ring 10 from the inside, as shown in FIGS. 2 and 3 . In addition to the first labyrinth slip 21 and the second labyrinth slip 22, the elastic body portion 20 also has, for example, a side lip 23, a radial lip 24, and a grease lip 25. The side lip 23, the radial lip 24, and the grease lip 25 are each annular seal lips around the axis x. As shown in FIGS. 2 and 3 , the radial lip 24 and the grease lip 25 extend toward the axis x (inner periphery) and, when the hub seal 1 is in use, come into contact with a fitting portion 32 of the slinger 4 (described later). When the hub seal 1 is in use, the side lip 23 comes into contact with a flange portion 31 of the slinger 4 (described later). The side lip 23 and radial lip 24 prevent foreign matter from entering the internal space S of the hub bearing 100 when the hub seal 1 is in use, and also prevent lubricant from leaking out from the internal space S. Furthermore, the grease lip 25 prevents lubricant from leaking out from the internal space S of the hub bearing 100 when the hub seal 1 is in use.

[0029] The elastic body portion 20 also has, for example, a base portion 26. As shown in FIGS. 2 and 3, the base portion 26 is a portion of the elastic body portion 20 that extends mainly over the inner surface of the reinforcing ring 10, spanning the tubular portion 11 and the lip support portion 12 of the reinforcing ring 10. As shown in FIGS. 2 and 3, the radial lip 24 and the grease lip 25 each extend from an inner peripheral end portion 26a, which is the inner peripheral end portion of the base portion 26. As shown in FIGS. 2 and 3, the side lip 23 extends from the inner peripheral end portion 26a of the base portion 26, radially spaced apart from the radial lip 24, on the outer peripheral side of the radial lip 24. As shown in FIGS. 2 and 3, the base portion 26 also extends over the outer peripheral surface 11d of the gasket support portion 11b of the reinforcing ring 10, forming a gasket portion 26b on the outer peripheral surface 11d of the gasket support portion 11b. 2 and 3, the gasket portion 26b protrudes radially outward beyond the outer peripheral surface 11c of the fitting portion 11a of the reinforcing ring 10, and is compressed radially between the gasket support portion 11b of the reinforcing ring 10 fitted into the inner opening 101c of the outer ring 101 and the inner peripheral surface 101e of the inner opening 101c. This provides a tight seal between the inner opening 101c of the outer ring 101 and the seal body 3.

[0030] 2 and 3, the elastic body portion 20 has an outer peripheral facing portion 26c that extends along the inner peripheral surface 11e, which is the inner peripheral surface of the tubular portion 11 of the reinforcing ring 10. When the hub seal 1 is in use, the outer peripheral facing portion 26c faces, across an annular gap, an inner peripheral facing portion 42 of the elastic body portion 40 that covers the tip of the flange portion 31 of the main body portion 30 of the slinger 4, which will be described later. The outer peripheral facing portion 26c has, for example, a facing surface 26d that extends along the axis x extending from the inner end, and faces the inner peripheral facing portion 42 of the slinger 4 at the facing surface 26d. The facing surface 26d is, for example, a cylindrical surface or an approximately cylindrical surface with the axis x as its central axis or approximately as its central axis. Furthermore, the opposing surface 26d extends, for example, to the outer edge of the gasket support portion 11b of the reinforcing ring 10 or close to this edge, or extends beyond the gasket support portion 11b to the outside.

[0031] 2 and 3, the side lip 23 extends inward from the base portion 26 in an annular shape, for example, with the axis x as its central axis or approximately as its central axis. Furthermore, as shown in FIG. 2, when the hub seal 1 is in use and the seal body 3 and slinger 4 are attached to the hub bearing 100 so that they are in a predetermined relative position, the side lip 23 is formed so that its tip contacts a flange portion 31 of the slinger 4 (described later) with a predetermined interference. Specifically, when the hub seal 1 is in use, the tip portion 23a of the side lip 23 contacts the flange portion 31 of the slinger 4. As shown in FIG. 3, the side lip 23 has, for example, a conical or approximately conical cylindrical shape that widens in diameter as it extends inward in the direction of the axis x.

[0032] 2 and 3, the radial lip 24 extends inward and toward the inner periphery from the inner peripheral end 26a of the base portion 26 in an annular shape with the axis x as its central axis or approximately its central axis. As shown in FIG. 2, the radial lip 24 is formed so that the tip portion 24a comes into contact with the fitting portion 32 of the slinger 4 with a predetermined interference when the hub seal 1 is in use. Also, the hub seal 1 does not necessarily have to have the radial lip 24.

[0033] 2 and 3, the grease lip 25 extends annularly from the base portion 26 toward the outer and inner periphery with the axis x as its central axis or approximate central axis. As shown in FIG. 2, the grease lip 25 is formed so that the tip portion 25a contacts the fitting portion 32 of the slinger 4 when the hub seal 1 is in use. Note that the grease lip 25 may be configured so that the tip portion 25a does not contact the fitting portion 32 of the slinger 4 when the hub seal 1 is in use. The hub seal 1 does not necessarily have to have a grease lip 25.

[0034] As described above, the first labyrinth slip 21 extends annularly inward around the axis x, and as shown in FIGS. 2 and 3 , forms an annular portion of the elastic body portion 20 that protrudes inward from the base portion 26. The width of the first labyrinth slip 21 narrows, for example, toward the tip portion 21a, which is the tip of the first labyrinth slip 21 and its vicinity. The first labyrinth slip 21 is located more inward than the outer circumferential facing portion 26c, and a recess 27, which is an annular portion recessed outward around the axis x, is formed between the first labyrinth slip 21 and the outer circumferential facing portion 26c. When the hub seal 1 is in use, the tip portion 21a of the first labyrinth slip 21 faces, with a gap therebetween, an inner circumferential facing portion 42 of the elastic body portion 40 of the slinger 4, described later, in the direction of the axis x.

[0035] As described above, the second labyrinth slip 22 extends inward in an annular shape around the axis x, and as shown in FIGS. 2 and 3 , forms an annular portion of the elastic body portion 20 that protrudes inward from the base portion 26. The width of the second labyrinth slip 22 narrows, for example, toward the tip portion 22a, which is the tip of the second labyrinth slip 22 and its vicinity. The second labyrinth slip 22 is located more inward than the first labyrinth slip 21, and a recess 28, which is an annular portion recessed outward around the axis x, is formed between the second labyrinth slip 22 and the first labyrinth slip 21. When the hub seal 1 is in use, the tip portion 22a of the second labyrinth slip 22 faces, with a gap therebetween, a flange portion 31 of a main body portion 30 of the slinger 4 (described later) in the direction of the axis x. In addition, the second labyrinth slip 22 is located on the outer circumferential side of the side lip 23, and a recess 29, which is an annular portion recessed outward around the axis x, is formed between the second labyrinth slip 22 and the side lip 23.

[0036] 2 and 3, the second labyrinth slip 22 is inclined outward toward the inner periphery. The outer periphery surface 22b, which is a cylindrical surface facing the outer periphery of the second labyrinth slip 22, expands in diameter toward the inner periphery in the direction of the axis x and is inclined outward toward the outer periphery toward the inner periphery. Similarly, the inner periphery surface 22c, which is a cylindrical surface facing the inner periphery of the second labyrinth slip 22, expands in diameter toward the inner periphery in the direction of the axis x and is inclined outward toward the outer periphery toward the inner periphery. Note that the second labyrinth slip 22 does not have to be inclined outward toward the outer periphery toward the inner periphery in the direction of the axis x. For example, the second labyrinth slip 22 may extend parallel to the direction of the axis x and may be inclined inward toward the inner periphery toward the inner periphery.

[0037] 2 and 3, the tip end 22a of the second labyrinth slip 22 is located more inward than the tip end 21a of the first labyrinth slip 21 in the direction of the axis x. That is, the height of the tip end 22a of the second labyrinth slip 22 from the bottom 27a of the recess 27 is higher than the height of the tip end 21a of the first labyrinth slip 21 from the bottom 27a of the recess 27. The heights of the tip ends 21a, 22a are the distances from the bottom 27a to the tip ends 21a, 22a, respectively, in the direction of the axis x. The bottom 27a of the recess 27 is the outermost part of the recess 27 in the direction of the axis x. The tip end 22a of the second labyrinth slip 22 does not have to be located more inward than the tip end 21a of the first labyrinth slip 21 in the direction of the axis x. For example, the tip end 22a of the second labyrinth slip 22 may be located further outward than the tip end 21a of the first labyrinth slip 21 in the direction of the axis x, or the tip end 22a of the second labyrinth slip 22 may be located at the same position as the tip end 21a of the first labyrinth slip 21 in the direction of the axis x.

[0038] 2 and 3, the recess 28 is formed deep, for example. Specifically, the bottom 28a of the recess 28 is located near the lip flange portion 12b of the reinforcing ring 10. The bottom 28a of the recess 28 is the outermost portion of the recess 28 in the direction of the axis x. The recess 28 is formed deeper than the recess 27, for example. The bottom 28a of the recess 28 may be located in the lip flange portion 12b of the reinforcing ring 10. In other words, the bottom 28a of the recess 28 may be formed by the lip flange portion 12b. The recess 28 does not have to be formed deep. The recess 28 does not have to be formed deeper than the recess 27.

[0039] The elastic body portion 20 is attached integrally to the reinforcing ring 10, and the above-mentioned first labyrinth slip 21, second labyrinth slip 22, side lip 23, radial lip 24, grease lip 25, and base portion 26 are each parts of the elastic body portion 20 integrally formed from the same material and are continuous as a whole. Examples of the elastic body of the elastic body portion 20 include various rubber materials. Examples of the various rubber materials include synthetic rubbers such as nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), and fluororubber (FKM).

[0040] As described above, the slinger 4 includes a main body portion 30 and an elastic body portion 40. As shown in FIGS. 2 and 3 , the main body portion 30 of the slinger 4 includes a flange portion 31, which is an annular portion extending radially around the axis x, and a fitting portion 32, which is a cylindrical portion extending outward in the direction of the axis x from the inner peripheral end of the flange portion 31 along the axis x. The flange portion 31 is a disc-shaped or approximately disc-shaped portion extending radially with the axis x as its central axis or approximately central axis. As shown in FIG. 2 , the flange portion 31 forms an annular portion protruding radially from the outer peripheral surface 102a of the inner ring 102. The contact surface 31a, which is the outer surface of the flange portion 31, extends, for example, on a plane parallel or approximately parallel to a plane perpendicular to the axis x. When the hub seal 1 is in use, the side lip 23 contacts the contact surface 31a of the flange portion 31.

[0041] As shown in Fig. 2, for example, the fitting portion 32 is a cylindrical or approximately cylindrical portion with the axis x as its central axis or approximate central axis, and is formed so as to be press-fitted into the inner ring 102 and fitted onto the outer peripheral surface 102a of the inner ring 102. Furthermore, the contact surface 32a, which is the surface facing the outer periphery of the fitting portion 32, is a cylindrical or approximately cylindrical surface with the axis x as its central axis or approximate central axis, as shown in Fig. 2, for example. When the hub seal 1 is in use, the radial lip 24 and the grease lip 25 come into contact with the fitting portion 32.

[0042] Furthermore, the main body 30 of the slinger 4 is adapted to fit tightly against the inner ring 102. Specifically, the fitting portion 32 of the main body 30 and the inner ring 102 are adapted to fit tightly against each other so that no gap through which foreign matter can pass is formed between the fitting portion 32 and the inner ring 102. Note that the main body 30 and the inner ring 102 do not have to be in tight contact as described above. In this case, for example, an annular gasket may be provided between the main body 30 and the inner ring 102 to prevent foreign matter from entering the internal space S between the outer ring 101 and the inner ring 102 through a gap between the main body 30 and the inner ring 102. For example, such a gasket is formed by the elastic body portion 40 of the slinger 4.

[0043] The main body 30 is integrally formed, for example, by pressing or forging a metal plate of uniform thickness, and the flange 31 and the fitting portion 32 are integrally formed parts of the slinger 4. Examples of metal materials for the main body 30 include stainless steel and SPCC (cold rolled steel). However, the material for the main body 30 is not limited to metal materials.

[0044] As shown in FIG. 2, the seal body 3 and the slinger 4 face each other radially outward from the first labyrinth slip 21, forming an annular gap S1 around the axis x. As described above, the elastic body portion 40 of the slinger 4 has an inner circumferential facing portion 42. As shown in FIG. 2, for example, the inner circumferential facing portion 42 is formed to cover the outer circumferential end portion 31b, which is the outer circumferential end portion of the flange portion 31 of the main body portion 30. The inner circumferential facing portion 42 has a facing surface 42a, which is an annular surface facing the outer circumferential side. When the hub seal 1 is in use, the facing surface 42a faces the facing surface 26d of the outer circumferential facing portion 26c of the elastic body portion 20 of the seal body 3 across the annular gap S1 in the radial direction. The facing surface 42a is, for example, a cylindrical surface or an approximately cylindrical surface with the axis x as its central axis or approximately its central axis. When the hub seal 1 is in use, the annular gap S1 formed between the opposing surface 42a of the slinger 4 and the opposing surface 26d of the seal body 3 forms, for example, a labyrinth seal. Note that the gap S1 does not necessarily have to form a labyrinth seal.

[0045] As described above, the elastic body portion 40 has the slinger rabby slip 41. The slinger rabby slip 41 extends outward in an annular shape around the axis x, and as shown in Fig. 2, forms an annular portion of the elastic body portion 40 that protrudes outward from the inner circumferential side of the inner circumferential facing portion 42. The slinger rabby slip 41 is provided, for example, adjacent to the inner circumferential side of the inner circumferential facing portion 42.

[0046] As described above, the tip portion 41a of the sling rabbyrinth slip 41 is located between the first labyrinth slip 21 and the second labyrinth slip 22 in the radial direction to form a labyrinth seal. The tip portion 41a of the sling rabbyrinth slip 41 is the tip of the sling rabbyrinth slip 41 and a portion in the vicinity of the tip. Specifically, for example, the tip portion 41a of the sling rabbyrinth slip 41 is located between the tip portion 21a of the first labyrinth slip 21 and the tip portion 22a of the second labyrinth slip 22 in the radial direction. The tip end 41a of the sling rabbyrinth slip 41 and the tip end 21a of the first labyrinth slip 21 are adjacent to each other, forming an annular gap (gap S2) therebetween. The tip end 41a of the sling rabbyrinth slip 41 and the tip end 22a of the second labyrinth slip 22 are adjacent to each other, forming an annular gap (gap S3) therebetween. The gaps S2 and S3 each form a labyrinth slip seal, and are gaps that form a labyrinth seal. The gaps S2 and S3 may be integrated with each other to form a single labyrinth seal. The gaps S2 and S3 may also be connected to each other via the recess 28 to form a single labyrinth seal. The labyrinth seals formed between the sling rabbyrinth slip 41, the first labyrinth slip 21, and the second labyrinth slip 22 may have other shapes.

[0047] Specifically, for example, as shown in Fig. 2, when the hub seal 1 is in use, the first labyrinth slip 21, the second labyrinth slip 22, and the sling rabbyrinth slip 41 overlap one another in the radial direction. In other words, when the hub seal 1 is in use, the first labyrinth slip 21, the second labyrinth slip 22, and the sling rabbyrinth slip 41 overlap in the direction of the axis x. In this case, when the hub seal 1 is in use, the tip end 41a of the sling rabbyrinth slip 41 is within the recess 28. Note that the tip end 41 of the sling rabbyrinth slip 41 and a portion of its inner side within a predetermined width in the direction of the axis x may be within the recess 28. For example, the first labyrinth slip 21 and the sling rabbyrinth slip 41 overlap at the tip end 21a and the tip end 41a. Also, for example, the first labyrinth slip 21 and the sling ravilin slip 41 overlap at the tip 21a and its outer portion and at the tip 41a and its inner portion. Similarly, for example, the second labyrinth slip 22 and the sling ravilin slip 41 overlap at the tip 22a and the tip 41a. Also, for example, the second labyrinth slip 22 and the sling ravilin slip 41 overlap at the tip 22a and its outer portion and at the tip 41a and its inner portion.

[0048] As shown in FIG. 2, the slinger rabby slip 41 is inclined outward toward the outer periphery. The outer periphery surface 41b, which is a cylindrical surface facing the outer periphery of the slinger rabby slip 41, expands in diameter outward in the direction of the axis x and is inclined outward toward the outer periphery. Similarly, the inner periphery surface 41c, which is a cylindrical surface facing the inner periphery of the slinger rabby slip 41, expands in diameter outward in the direction of the axis x and is inclined outward toward the outer periphery. Note that the slinger rabby slip 41 does not have to be inclined outward toward the outer periphery in the direction of the axis x. For example, the slinger rabby slip 41 may extend parallel to the direction of the axis x, or may be inclined inward toward the inner periphery.

[0049] 2, the elastic body portion 40 has a cover portion 43 that is a portion formed so as to cover the flange portion 31 from the inside. The cover portion 43 is located close to the inner facing portion 42 on the inner circumferential side. Note that the elastic body portion 40 does not necessarily have to have the cover portion 43.

[0050] The elastic body portion 40 is attached integrally to the main body portion 30, and the above-mentioned sling rubber slip 41, inner peripheral facing portion 42, and cover portion 43 are each parts of the elastic body portion 40 formed integrally from the same material and are continuous as one unit. Examples of the elastic body of the elastic body portion 40 include various rubber materials. Examples of the various rubber materials include synthetic rubbers such as nitrile rubber (NBR), nitrile-based magnetic rubber, hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), and fluororubber (FKM).

[0051] The hub seal 1 has the configuration described above, and when the hub seal 1 is in use, the side lip 23 of the seal body 3 contacts the flange portion 31 of the main body 30 of the slinger 4, and the radial lip 24 of the seal body 3 contacts the fitting portion 32 of the main body 30 of the slinger 4. This primarily prevents foreign matter such as rainwater, muddy water, and dust from entering the internal space S of the hub bearing 100 from the outside. Furthermore, when the hub seal 1 is in use, the grease lip 26 of the seal body 3 contacts the fitting portion 32 of the main body 30 of the slinger 4. This primarily prevents the lubricant in the internal space S of the hub bearing 100 from leaking to the outside.

[0052] When the hub seal 1 is in use, the sling rabbyrinth slip 41 and the first labyrinth slip 21 are close to each other, forming a gap S2 therebetween that functions as a labyrinth seal. The sling rabbyrinth slip 41 and the second labyrinth slip 22 are close to each other, forming an annular gap S3 therebetween that functions as a labyrinth seal. This prevents foreign matter that has entered from the outside through the gap S1 from further penetrating toward the side lip 23. This prevents foreign matter from approaching the side lip 23 and, ultimately, the radial lip 24. This prevents damage to the side lip 23 and the contact surface 31a of the flange portion 31 caused by foreign matter getting caught, and thus prevents a deterioration in the sealing performance of the side lip 23 and, ultimately, a deterioration in the sealing performance of the radial lip 24.

[0053] When the first labyrinth slip 21, the second labyrinth slip 22, and the sling labyrinth slip 41 overlap in the direction of the axis x while the hub seal 1 is in use, the labyrinth seals formed by the gaps S2 and S3 can be lengthened, improving the sealing performance of the formed labyrinth seals. Also, when the gap S2, the recess 28, and the gap S3 form an integrated labyrinth seal and function as an integrated labyrinth seal, the sealing performance of the formed labyrinth seal can be improved.

[0054] When the hub seal 1 is in use, the tip end 21a of the first labyrinth slip 21 faces the inner peripheral facing portion 42 of the elastic body portion 40 of the slinger 4 with a gap in the direction of the axis x, and the tip end 22a of the second labyrinth slip 22 faces the flange portion 31 of the main body portion 30 of the slinger 4 with a gap in the direction of the axis x. In addition, the tip end 41a of the sling labyrinth slip 41 faces the bottom portion 28a of the recessed portion 28 or its vicinity with a gap in the direction of the axis x. If any one, any two, or all of the gap between the tip portion 21a of the first labyrinth slip 21 and the inner peripheral opposing portion 42, the gap between the tip portion 22a of the second labyrinth slip 22 and the flange portion 31, and the gap between the tip portion 41a of the sling labyrinth slip 41 and the recess 28 form a labyrinth seal, the sealing performance of the labyrinth seal formed between the first labyrinth slip 21, the second labyrinth slip 22, and the sling labyrinth slip 41 can be further improved.

[0055] Furthermore, a recess 28 is formed between the first labyrinth slip 21 and the second labyrinth slip 22, and the recess 28 acts to retain foreign matter that has entered the interior through the gap S2. Therefore, the recess 28 retains foreign matter that has entered the interior through the gap S2, and can prevent the foreign matter from further approaching the side lip 23. This also enables the hub seal 1 to prevent a deterioration in the sealing performance of the side lip 23.

[0056] Furthermore, when the second labyrinth slip 22 is inclined toward the outer periphery as it faces inward, and the outer periphery 22b of the second labyrinth slip 22 is inclined toward the outer periphery as it faces inward, the tip end 22a of the second labyrinth slip 22 is located closer to the outer periphery than the base end of the second labyrinth slip 22. Therefore, in this case, the recess 28 can improve the function of retaining foreign matter that has entered the interior through the gap S2, and can further prevent foreign matter from approaching the side lip 23.

[0057] Furthermore, when the second labyrinth slip 22 is inclined outwardly toward the inside and the inner peripheral surface 22c of the second labyrinth slip 22 is inclined outwardly toward the inside, the tip end 22a of the second labyrinth slip 22 is located closer to the outside circumference than the base end portion of the second labyrinth slip 22. Therefore, in this case, the rotation of the outer ring 101 causes the seal body 3 to rotate, improving the function of expelling foreign matter that has entered the recess 29 from the recess 29 to the outside circumference, and preventing the foreign matter from getting any closer to the side lip 23.

[0058] Furthermore, when the slinger rabby slip 41 is inclined outward toward the outer periphery and the outer peripheral surface 41b of the slinger rabby slip 41 is inclined outward toward the outer periphery, the tip 41a of the slinger rabby slip 41 is located closer to the outer periphery than the base portion of the slinger rabby slip 41. Therefore, in this case, the slinger rabby slip 41 acts as an obstacle to further penetration of foreign matter that has entered the interior through the gap S1, and can further prevent foreign matter from approaching the side lip 23.

[0059] Furthermore, when the hub seal 1 is in use, the outer peripheral facing portion 26c of the elastic body portion 20 of the seal body 3 and the inner peripheral facing portion 42 of the elastic body portion 40 of the slinger 4 face each other in the radial direction, forming an annular gap S1. Gap S1 acts as a further obstacle to the entry of foreign matter entering the interior of the hub seal 1 from the outside, and can further prevent foreign matter from entering the interior of the hub seal 1. When gap S1 forms a labyrinth seal, it can further prevent foreign matter from entering the interior of the hub seal 1.

[0060] Additionally, the hub seal 1 improves its sealing performance by forming a complex labyrinth seal without increasing the portion of the seal body 3 that contacts the main body 30 of the slinger 4 in addition to the side lip 23, radial lip 24, and grease lip 25. This makes it possible to suppress an increase in torque resistance that occurs between the seal body 3 and the slinger 4 when the outer ring 101 rotates relative to the inner ring 102. Furthermore, even if the diameter of the hub seal 1 increases, the labyrinth seal formed by the hub seal 1 does not increase the torque resistance that occurs between the seal body 3 and the slinger 4.

[0061] As described above, the hub seal 1 according to the embodiment of the present invention can suppress a decrease in sealing performance even when the diameter of the hub seal 1 is increased, and can also suppress an increase in torque resistance.

[0062] The hub seal 1 may have a plurality of second labyrinth slips 22. In this case, for example, a plurality of second labyrinth slips 22 are provided between the first labyrinth slip 21 and the side lip 23 in the elastic body portion 20 of the seal body 3. Similarly, the hub seal 1 may have a plurality of sling rabbyrinth slips 41. In this case, for example, a plurality of sling rabbyrinth slips 41 are provided on the inner circumferential side of the inner circumferential side opposing portion 42 in the elastic body portion 40 of the slinger 4. When a plurality of second labyrinth slips 22 and a plurality of sling rabbyrinth slips 41 are provided, for example, the same number of each are provided, and the plurality of second labyrinth slips 22 and the plurality of sling rabbyrinth slips 41 are paired, forming gaps S2 as described above and forming a labyrinth seal.

[0063] Although the present invention has been described above through the above embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0064] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the scope of the present invention. Furthermore, the above-described embodiments do not limit the scope of the present invention, and the present invention may include any and all applications. The components of the above-described embodiments, as well as their arrangement, materials, conditions, shape, size, etc., are not limited to those illustrated and may be modified as appropriate. For example, the present invention includes differences that arise during implementation due to manufacturing tolerances, etc. Furthermore, components illustrated in different embodiments may be partially substituted or combined within the scope of technical inconsistency. Furthermore, the various configurations may be selectively combined as appropriate to achieve at least some of the above-described problems and effects.

[0065] For example, the application of the sealing device according to the present invention is not limited to hub bearings. For example, as shown in Fig. 4, the hub seal 1 can also be applied to an in-wheel motor unit in which an outer peripheral member rotates. An in-wheel motor unit is a drive device that integrates a hub bearing and a motor, and is attached to the wheel of a vehicle. The motor output is supplied to the wheel via the hub bearing to power the wheel, and the wheel power is converted into electric power via a motor generator to generate electricity.

[0066] Fig. 4 is a cross-sectional view of an example of an in-wheel motor unit as an example of an application of the present invention. For example, as shown in Fig. 4, an in-wheel motor unit 200 includes an inner-ring-rotating hub bearing 110, an outer casing 201 as an outer peripheral member attached to the hub bearing 110, an inner casing 202 as an inner peripheral member, and a motor generator 203. Specifically, the outer casing 201 is a cylindrical member and forms an inner space that houses the hub bearing 110. The outer casing 201 is sandwiched between a wheel mounting flange 113 provided on an inner ring 112 of the hub bearing 110 and a brake disc 114 attached to the wheel mounting flange 113, and is fixed between the wheel mounting flange 113 and the brake disc 114 by fixing the wheel to the inner ring 112 with hub bolts 115.

[0067] The inner casing 202 has a cylindrical portion 202a, which is a cylindrical member that forms an inner peripheral space that accommodates the outer ring 111 of the hub bearing 110, and a disk portion 202b, which is a disk-shaped portion that extends from the inner end of the cylindrical portion 202a toward the outer peripheral side. The cylindrical portion 202a is shaped so that the outer ring 111 is fitted into and fixed in the inner peripheral space. As shown in FIG. 4, the outer casing 201 and the inner casing 202 are shaped so that the inner peripheral surface of the outer casing 201 and the outer peripheral surface of the cylindrical portion 202a of the inner casing 202 face each other, forming an annular space between the outer casing 201 and the cylindrical portion 202a. Furthermore, as shown in FIG. 4, the outer casing 201 and the inner casing 202 are shaped so that the inner end (end 201a) of the outer casing 201 faces the disk portion 202b of the inner casing 202 in the direction of the axis x. An annular gap is formed between the end 201a of the outer casing 201 and the disk portion 202b.

[0068] The motor generator 203 is a cylindrical member extending along the axis x, and is provided in the annular space between the outer casing 201 and the cylindrical portion 202a of the inner casing 202. Specifically, the motor generator 203 includes a rotor 204 and a stator 205, the rotor 204 being fixed to the outer casing 201, and the stator 205 being fixed to the cylindrical portion 202a of the inner casing 202.

[0069] In the in-wheel motor unit 200, the hub seal 1 is provided to prevent foreign matter from entering the interior of the in-wheel motor unit 100 through an annular gap between the end portion 201a of the outer casing 201 and the disc portion 202b of the inner casing 202. For example, as shown in FIG. 4 , the hub seal 1 is attached between the end portion 201a of the outer casing 201 and the disc portion 202b of the inner casing 202. Specifically, a slinger 4 is press-fitted and fitted onto a mounting surface 202c of the disc portion 202b of the inner casing 202, and the slinger 4 is fixed to the disc portion 202b of the inner casing 202. Furthermore, specifically, the seal body 3 is press-fitted and fitted onto the mounting surface 201b of the end portion 201a of the outer casing 201, and the seal body 3 is fixed to the outer casing 201. The mounting surface 202c of the disk portion 202b of the inner casing 202 is a cylindrical surface extending along the axis x, and the mounting surface 201b of the end portion 201a of the outer casing 201 is a cylindrical surface extending along the axis x. The mounting surfaces 201b and 202c are opposed to each other in the radial direction.

[0070] In the in-wheel motor unit 200, when the inner ring 112 of the hub bearing 110 rotates due to the driving force of the motor generator 203 of the in-wheel motor 200, the seal body 3 of the hub seal 1 rotates relative to the slinger 4. In the in-wheel motor unit 200, as in the case of the hub bearing 100 described above, the hub seal 1 is in use, and as in the case of the hub bearing 100 described above, the hub seal 1 acts and produces an effect.

[0071] Furthermore, the application of the sealing device according to the present invention is not limited to those in which an outer peripheral member rotates relative to an inner peripheral member. For example, a hub bearing to which the sealing device according to the present invention is applied may not be an outer ring rotating type like the above-mentioned hub bearing 100, but may be an inner ring rotating type hub bearing in which the outer ring is fixed and the inner ring rotates. [Explanation of symbols]

[0072] 1, 2 Hub seal (sealing device), 3 Seal body (sealing device body), 4 Slinger, 10 Reinforcing ring, 11 Cylindrical portion, 11a Fitting portion, 11b Gasket support portion, 11c, 11d Outer peripheral surface, 11e Inner peripheral surface, 12 Lip support portion, 12a Return portion, 12b Lip flange portion, 20 Elastic body portion, 21 First labyrinth lip, 21a Tip portion, 21b Outer peripheral surface, 21c Inner peripheral surface, 22 Second labyrinth lip, 22a Tip portion, 22b Outer peripheral surface, 22c Inner peripheral surface, 23 Side lip, 23a Tip portion, 24 Radial lip, 24a Tip portion, 25 Grease lip, 25a Tip portion, 26 Base portion, 26a Inner peripheral end portion, 26b Gasket portion, 26c Outer peripheral opposing portion, 26d Counter surface, 27, 28, 29 recess, 27a, 28a bottom, 30 main body, 31 flange, 31a contact surface, 31b outer peripheral end, 32 fitting portion, 32a contact surface, 40 elastic body portion, 41 sling rubber slip, 41a tip portion, 41b outer peripheral surface, 41c inner peripheral surface, 42 inner peripheral counter portion, 42a counter surface, 43 cover portion, 100, 110 hub bearing, 101, 111 outer ring, 101a cylindrical portion, 101b, 113 wheel mounting flange portion, 101c inner opening, 101d outer opening, 101e inner peripheral surface, 102 inner ring, 102a outer peripheral surface, 103 bearing ball, 104 cage, 105 through hole, 106, 115 hub bolt, 114 Brake disc, 200 in-wheel motor unit, 201 outer casing, 201a end, 201b mounting surface, 202 inner casing, 202a cylindrical portion, 202b disc portion, 202c mounting surface, 203 motor generator, 204 rotor, 205 stator, S1, S2, S3 gap, x-axis

Claims

1. A sealing device for sealing a gap between an outer peripheral member and an inner peripheral member at least partially surrounded by the outer peripheral member, the outer peripheral member being rotatable relative to each other about an axis, a sealing device main body fixed to the outer circumferential member; a slinger fixed to the inner peripheral member, the sealing device main body includes a reinforcing ring that is an annular member around the axis, and an elastic body portion that is attached to the reinforcing ring and is formed from an annular elastic body around the axis, The slinger includes a main body portion that is an annular member around the axis, and an elastic body portion that is attached to the main body portion and is formed from an annular elastic body around the axis, the elastic body portion of the sealing device main body has a first labyrinth slip and a second labyrinth slip, each of which is annular around the axis and extends toward one side in the axial direction, The elastic body portion of the slinger has a slinger rabbet slip which is a portion that is annular around the axis and extends toward the other side in the axial direction, the second labyrinth slip is located more inwardly than the first labyrinth slip, The tip end of the sling labyrinth slip is positioned between the first labyrinth slip and the front second labyrinth slip in the radial direction to form a labyrinth seal. Sealing device.

2. The first labyrinth slip, the front second labyrinth slip, and the sling labyrinth slip are configured to overlap each other when viewed in the radial direction. The sealing device according to claim 1 .

3. a recessed portion that is an annular portion recessed toward the other side in the axial direction around the axis is formed between the first labyrinth slip and the second labyrinth slip; The sealing device according to claim 1 .

4. The sling rubber slip is inclined outwardly toward the other side in the axial direction. The sealing device according to claim 1 .

5. The second labyrinth slip is inclined outwardly toward one side in the axial direction. The sealing device according to claim 1 or 3.

6. On the outer circumferential side of the first labyrinth slip, the sealing device body and the slinger face each other in the radial direction to form an annular gap around the axis. The sealing device according to claim 1 .

7. The main body of the slinger has a flange portion that is an annular portion extending radially around the axis, and a fitting portion that is a cylindrical portion extending from an inner peripheral end of the flange portion along the axis toward the other side in the axial direction, The elastic body portion of the sealing device main body has an annular radial lip around the axis formed so as to contact the fitting portion of the main body portion of the slinger. The sealing device according to claim 1 .

8. The outer peripheral member rotates, and the inner peripheral member is fixed. The sealing device according to claim 1 .

Images