Sealing device

Abstract

To provide a sealing device of which the torque is reduced and the lifetime is prolonged while suppressing intrusion of a foreign substance such as muddy water.SOLUTION: A sealing device 10 for sealing an annular space S formed between an outer member and an inner member, which are relatively rotated, comprises: a first member 11 in which a first cylindrical part 131 is fitted to an inner peripheral surface 2c of the outer member; and a second member 12 in which a second cylindrical part 151 is fitted to an outer peripheral surface 4b of the inner member. The first member includes a first water repellent part 113 which is provided on an inner peripheral surface of the first cylindrical part and has water repellency. The second member includes: a third cylindrical part 153 opposed to the first cylindrical part in a radial direction; and a second water repellent part 124 which is provided at least on an outer peripheral surface of the third cylindrical part and has water repellency. The first water repellent part and the second water repellent part are provided in a proximate manner while being opposed to each other, thereby constituting a labyrinth seal R extending in an axial direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a sealing device for sealing an annular space formed between outer and inner members which rotate relative to one another. [Background technology]

[0002] For example, a bearing device for a wheel of an automobile or the like is equipped with a sealing device that seals between the outer member and the inner member as described above in order to prevent foreign matter such as muddy water or dust from entering from the outside. In such a sealing device, a seal lip provided on the core member comes into contact with the slinger member, thereby preventing foreign matter such as muddy water from entering from the outside from entering the inside of the bearing device.

[0003] The following Patent Document 1 discloses a sealing device in which a coating layer formed by coating a water-repellent material on the surface of a portion that is susceptible to attack by foreign matter from the outside is formed. Also, the following Patent Document 2 discloses a sealing device having a water-repellent treatment layer formed by coating a water-repellent material on the surface of an exposed portion of the sealing device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-332990 A [Patent Document 2] JP 2009-298367 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, in Patent Documents 1 and 2, the seal lip is coated with a water-repellent coating. Therefore, there is a concern that the water repellency will decrease due to wear, damage, peeling, etc. of the coating caused by friction due to sliding contact between the seal lip and the slinger member and the ingress of foreign matter such as muddy water into the sliding contact portion. In addition, in Patent Documents 1 and 2, the seal lip is easily touched directly by foreign matter such as muddy water when the seal lip is invaded through an opening formed between the slinger member and the core member, and there is a concern that the coating will be worn, damaged, peeled, etc. by contacting the foreign matter. In addition, there is a concern that the coating will be worn, damaged, peeled, etc. by contacting foreign matter such as muddy water on parts other than the seal lip, and the effect of suppressing the intrusion of foreign matter such as muddy water will decrease. In addition, in Patent Document 2, the entire exposed part of the sealing device is coated with a water-repellent substance, so there is a concern that the manufacturing process will become complicated and the manufacturing cost will increase.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a sealing device that has low torque and a long life while suppressing the intrusion of foreign matter such as muddy water. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the sealing device of the present invention is a sealing device that seals an annular space formed between an outer member and an inner member that rotate relative to one another, and comprises a first member having a first cylindrical portion fitted onto an inner surface of the outer member, and a second member having a second cylindrical portion fitted onto an outer surface of the inner member, wherein the first member has a first water-repellent portion having water-repellent properties and provided on the inner surface of the first cylindrical portion, and the second member has a third cylindrical portion radially opposed to the first cylindrical portion, and a second water-repellent portion having water-repellent properties and provided on at least the outer surface of the third cylindrical portion, and the first water-repellent portion and the second water-repellent portion are arranged opposite and in close proximity to each other, thereby forming a labyrinth seal extending in the axial direction.

[0008] In the above sealing device, the first water-repellent portion may have an uneven structure provided on the inner circumferential surface of the first cylindrical portion.

[0009] In the sealing device, the first water-repellent portion may be made of an elastic body having water-repellent properties.

[0010] Moreover, in the sealing device, the second water-repellent portion may be an uneven structure provided on the outer circumferential surface of the third cylindrical portion.

[0011] In the sealing device, the second water-repellent portion may be made of an elastic body having water-repellent properties.

[0012] In addition, in the above sealing device, the second member may include a slinger member having a slinger ring portion extending radially outward from the second cylindrical portion, and the third cylindrical portion may be constituted by an elastic body fixed to the slinger ring portion and extending axially so as to face the first cylindrical portion.

[0013] In addition, in the above sealing device, an outer water-repellent portion having water-repellent properties may be provided on at least one of the axial outer end face of the first cylindrical portion and the axial outer surface of the portion of the second member that is connected to the third cylindrical portion.

[0014] In addition, in the above sealing device, the second member may include a slinger member having a slinger ring portion extending radially outward from the second cylindrical portion, and the first member may include a first seal lip extending toward and in sliding contact with the slinger ring portion, and a second seal lip extending toward and in sliding contact with the second cylindrical portion. Effect of the Invention

[0015] Since the sealing device of the present invention has the above-mentioned configuration, it has low torque and a long life while suppressing the intrusion of foreign matter such as muddy water. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic vertical cross-sectional view showing an example of a bearing assembly to which a sealing device according to each embodiment is attached; [Diagram 2]2 is an enlarged view of a portion X in FIG. 1, and is a schematic vertical sectional view showing a sealing device according to a first embodiment. FIG. [Diagram 3] 2, (a) is an enlarged view of portion Z in FIG. 2, and is a schematic vertical cross-sectional view showing the uneven structure, (b) is a schematic plan view of (a), (c) is a schematic vertical cross-sectional view showing a modified example of the uneven structure, (d) is a schematic vertical cross-sectional view showing another modified example of the uneven structure, (e) is a schematic plan view showing yet another modified example of the uneven structure, and (f) is a schematic plan view of (e). [Figure 4] 10A is a schematic vertical cross-sectional view showing a sealing device according to a second embodiment, and FIGS. 10B and 10C are explanatory views for explaining modified examples of the second member in the sealing device. [Diagram 5] 13A is a schematic vertical cross-sectional view showing a sealing device according to a third embodiment, and FIG. 13B and FIG. 13C are explanatory views for explaining modified examples of the second member in the sealing device. [Figure 6] FIG. 11 is a schematic vertical cross-sectional view showing a sealing device according to a fourth embodiment. [Figure 7] 1, and is a schematic vertical sectional view showing a sealing device according to a fifth embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] First Embodiment Each embodiment will be described below with reference to the drawings. Note that in some drawings, some of the detailed reference numerals attached to other drawings are omitted. In the following, the side facing the wheel along the axis L (left side in FIG. 1, etc.) is referred to as the wheel side, and the side facing the vehicle body (right side in FIG. 1, etc.) is referred to as the vehicle body side. In the drawings, the part of the seal lip shown by the two-dot chain line shows the original shape before deformation. In the drawings, the dashed line A shows that an uneven structure is provided on the surface of the member along the dashed line A. First, a sealing device according to a first embodiment will be described with reference to FIGS. 1 to 3.

[0018] The sealing device 10 according to the first embodiment is a device for sealing an annular space S formed between an outer member and an inner member that rotate relative to each other. The sealing device 10 includes a first member 11 having a first cylindrical portion fitted to an inner peripheral surface 2c of the outer member, and a second member 12 having a second cylindrical portion fitted to an outer peripheral surface 4b of the inner member. The first member 11 includes a first water-repellent portion 113 having water repellency provided on the inner peripheral surface of the first cylindrical portion. The second member 12 includes a third cylindrical portion radially opposed to the first cylindrical portion, and a second water-repellent portion 124 having water repellency provided on at least the outer peripheral surface of the third cylindrical portion. In the sealing device 10, the first water-repellent portion 113 and the second water-repellent portion 124 are provided adjacent to each other while facing each other, thereby forming a labyrinth seal R extending in the axial direction. The details are explained below.

[0019] <Bearing device> FIG. 1 shows a bearing device 1 that supports an automobile wheel (not shown) so as to be rotatable about its axis. This bearing device 1 is generally composed of an outer ring 2 corresponding to the outer member described above, an inner ring 5 corresponding to the inner member described above, and two rows of rolling elements (balls) 6... interposed between the outer ring 2 and the inner ring 5. The inner ring 5 is composed of a hub ring 3 and an inner ring member 4 as a rotating member, and the inner ring member 4 is fitted integrally with the vehicle body side of the hub ring 3. A drive shaft 7 is coaxially spline-fitted with the hub ring 3, and the drive shaft 7 is connected to a drive source (drive transmission part) (not shown) via a constant velocity joint 8. The drive shaft 7 is integrated with the hub ring 3 by a nut 9, and is prevented from falling off the drive shaft 7 of the hub ring 3. The inner ring 5 (hub ring 3 and inner ring member 4) is a rotating member that can rotate around an axis L with respect to the outer ring 2, and the outer ring 2 and the inner ring 5 constitute two members that rotate relatively to each other, forming an annular space S. Two rows of rolling elements 6 are held by a retainer 6a, and the raceways 2a of the outer ring 2, the hub ring 3, and the raceways 3a, 4a of the inner ring member 4 are rollably interposed within the annular space S. The hub ring 3 has a cylindrical hub ring body 30 and a hub flange 32 formed to extend radially outward from the hub ring body 30 via a rising base portion 31, and a wheel is attached and fixed to the hub flange 32 by bolts 33 and nuts (not shown).

[0020] In the above-mentioned annular space S, a sealing device 10 is attached to an end on the vehicle body side, and a sealing device 20 is attached to an end on the wheel side. Fig. 2 is a partial cross-sectional view in which a portion X in Fig. 1 showing the end on the vehicle body side of the annular space S and its vicinity is enlarged, and shows the sealing device 10 according to the first embodiment. Next, each member constituting the sealing device 10 will be described.

[0021] The sealing device 10 according to the first embodiment includes a first member 11 having a first cylindrical portion fitted to an inner peripheral surface 2c of an outer ring 2 which is an outer member, and a second member 12 having a second cylindrical portion fitted to an outer peripheral surface 4b of an inner ring member 4 which is an inner member. In the first embodiment, the first member 11 includes a core member 13 and a seal member 14, and the second member 12 includes a slinger member 15 and a magnetic encoder unit 16.

[0022] The core member 13 is formed by pressing a steel plate such as SPCC or SUS, and has a cylindrical shape with one side having a cross section of a substantially inverted L shape as shown in Fig. 2. The core member 13 includes a core cylindrical portion 131, which is the first cylindrical portion described above that is fitted into the inner peripheral surface 2c of the outer ring 2, and a core ring portion 132 that extends radially inward from an end portion 131a of the core cylindrical portion 131 on the wheel side. In addition, a stepped portion 131da is formed on the vehicle body side of the outer peripheral surface 131d of the core cylindrical portion 131, which is stepped down radially inward.

[0023] The seal member 14 is made of an elastic body such as rubber, and is integrally molded by vulcanization bonding to the core member 13. The seal member 14 includes a seal cylindrical portion 141 fixed to the core cylindrical portion 131 of the core member 13, and a seal ring portion 142 fixed to a part of the wheel side of the inner circumferential surface 131c of the core cylindrical portion 131 and to the core ring portion 132. Furthermore, the seal member 14 includes a first seal lip 143A and a second seal lip 143B extending from the seal ring portion 142.

[0024] The seal member 14 may also be integrally provided with two types of elastic bodies made of different materials by various molding methods such as two-color molding. The cylindrical seal portion 141 and the ring seal portion 142 may be formed of different types of elastic bodies, and at least the cylindrical seal portion 141 constituting the labyrinth seal R is formed of an elastic body having water repellency. Hereinafter, the elastic body having water repellency is referred to as water repellent rubber. Examples of the water repellent rubber forming the cylindrical seal portion 141 include silicone rubber, and examples of the elastic body forming the ring seal portion 142 include acrylonitrile butadiene rubber (NBR), hydrogenated nitrile rubber (H-NBR), ethylene propylene rubber (EPDM), acrylic rubber (ACM), ethylene acrylate rubber (AEM), fluororubber (FKM), silicone rubber, etc.

[0025] The seal cylindrical portion 141 is fixed to the core cylindrical portion 131 so as to cover most of the vehicle body side of the inner peripheral surface 131c of the core cylindrical portion 131, the vehicle body side end portion 131b, and the stepped portion 131da of the outer peripheral surface 131d. The seal ring portion 142 is fixed to the core cylindrical portion 132 so as to cover a radially inner part of the wheel side surface 132a of the core cylindrical portion 132, the radially inner end portion 132c, and the entire surface of the vehicle body side surface 132b.

[0026] Since the cylindrical seal portion 141 is formed of water-repellent rubber, the first member 11 includes a first water-repellent portion 113 having water-repellent properties provided on the inner circumferential surface 131c of the cylindrical core portion 131, and a first outer water-repellent portion 114 provided on the vehicle body side end portion 131b of the cylindrical core portion 131. The inner circumferential surface 113a of the first water-repellent portion 113 is inclined radially outward from the wheel side to the vehicle body side, making it easier to discharge foreign matter such as muddy water to the outside along the inner circumferential surface 113a.

[0027] The first seal lip 143A is an axial lip for preventing further intrusion of foreign matter such as muddy water, and expands in diameter from the seal ring portion 142 toward the vehicle body side, and extends and makes sliding contact with a slinger ring portion 152 side of the second member 12 described later. The second seal lip 143B is a grease lip for preventing grease filled in the annular space S from entering the sealing device 10, and extends from the seal ring portion 142 toward the wheel side with a reduced diameter, and extends and makes sliding contact with the slinger inner circumference side cylindrical portion 151 side, which is the above-mentioned second cylindrical portion. The sealing device 10 of this embodiment is configured to include one each of the first seal lip 143A which is an axial lip and the second seal lip 143B which is a grease lip.

[0028] The second member 12 includes a slinger member 15 and a magnetic encoder unit 16. The slinger member 15 is formed by pressing a steel plate such as SPCC or SUS, and has a cylindrical shape with a cross section on one side being substantially inverted C-shaped as shown in FIG. 2. The slinger member 15 includes a slinger inner circumference side cylindrical portion 151, which is the second cylindrical portion described above, a slinger ring portion 152, and a slinger outer circumference side cylindrical portion 153, which is the third cylindrical portion described above. The slinger inner circumference side cylindrical portion 151 is formed in a cylindrical shape that is fitted to the outer circumferential surface 4b of the inner ring member 4. The slinger ring portion 152 is formed by extending radially outward from an end portion 151b of the slinger inner circumference side cylindrical portion 151 on the vehicle body side. The slinger outer circumference side cylindrical portion 153 is formed by extending from an end portion 152d of the slinger ring portion 152 on the outer diameter side to the wheel side.

[0029] The slinger member 15 is subjected to a water-repellent treatment using an uneven structure in a portion along the dashed line A shown in Fig. 2. In this embodiment, the water-repellent treatment using an uneven structure is applied to the entire outer circumferential surface 153d of the slinger outer circumferential cylindrical portion 153 and to a portion of the radially outer side of the vehicle body side surface 152b of the slinger ring portion 152 that is not covered by the magnetic encoder portion 16.

[0030] The second member 12 includes a second water-repellent portion 124 having an uneven structure provided on the outer peripheral surface 153d of the slinger outer peripheral cylindrical portion 153. As shown in FIG. 3(a)(b), a plurality of convex portions 124a formed to protrude radially outward are provided continuously at intervals on the outer peripheral surface 153d of the slinger outer peripheral cylindrical portion 153. A concave portion 124b is provided between the plurality of convex portions 124a, which is the outer peripheral surface 153d of the slinger outer peripheral cylindrical portion 153. The plurality of convex portions 124a and the concave portion 124b are provided on the outer peripheral surface 153d of the slinger outer peripheral cylindrical portion 153, thereby forming a second water-repellent portion 124 having an uneven structure. This second water-repellent portion 124 has a lotus effect due to the uneven structure.

[0031] The lotus effect is an effect in which a fine uneven structure is provided on the surface of a member, which increases the contact angle of water with the surface of the member like a lotus leaf, thereby repelling water. The second water-repellent portion 124 having the lotus effect is formed by forming an uneven structure by periodically providing convex portions 124a and concave portions 124b on the outer peripheral surface 153d of the slinger outer peripheral cylindrical portion 153 using laser processing technology or the like. As shown in the schematic diagram of FIG. 3(a), water W adhering to the second water-repellent portion 124 is repelled in a spherical shape because the contact angle θ of water with the second water-repellent portion 124 is 90 degrees or more. In this way, the second water-repellent portion 124 has an uneven structure having the lotus effect, which increases the contact angle θ of water, making it easier to discharge foreign matter containing water, such as muddy water, to the outside.

[0032] A magnetic encoder unit 16 is provided on the vehicle body side surface 152b of the slinger ring portion 152 so as to face the magnetic sensor 40 provided on the vehicle body side. The magnetic encoder unit 16 includes a magnetic ring portion 161 that covers the vehicle body side surface 152b of the slinger ring portion 152. The magnetic encoder unit 16 is magnetized with N poles and S poles alternately and continuously in the circumferential direction, and can detect the rotation speed of the inner ring 5 and the like by cooperating with the magnetic sensor 40.

[0033] A second outer water-repellent portion 125 having water-repellent properties due to an uneven structure similar to the second water-repellent portion 124 is formed on a part of the vehicle body side surface 152b of the slinger circular ring portion 152 connected to the slinger outer circumferential cylindrical portion 153. The second outer water-repellent portion 125 is formed on a radially outer portion of the magnetic encoder portion 16 on the vehicle body side surface 152b of the slinger circular ring portion 152.

[0034] The first member 11 and the second member 12 are disposed opposite to each other. As a result, in the sealing device 10, a space 144 is formed that is surrounded by the first seal lip 143A, the wheel side surface 152a of the slinger circular ring portion 152, the inner circumferential surface 153c of the slinger outer circumferential cylindrical portion 153, and the seal circular ring portion 142.

[0035] In the sealing device 10, the first water-repellent portion 113 and the second water-repellent portion 124 are provided close to each other while facing each other in the radial direction, thereby forming a labyrinth seal R extending in the axial direction. Since the labyrinth seal R is configured in a non-contact manner, it has low torque and a long life while suppressing the intrusion of muddy water and the like. In addition, since the first water-repellent portion 113 and the second water-repellent portion 124 are in a non-contact manner, the first water-repellent portion 113 and the second water-repellent portion 124 do not come into contact with each other and wear thereon, so wear is suppressed and the water repellency can be maintained for a long time.

[0036] In addition, the first member 11 and the second member 12 are provided with a first outer water-repellent portion 114 and a second outer water-repellent portion 125 having water repellency adjacent to the opening of the labyrinth seal R. By providing the first outer water-repellent portion 114 and the second outer water-repellent portion 125 adjacent to the opening of the labyrinth seal R, foreign matter such as muddy water is not attracted, and the foreign matter is less likely to invade the labyrinth seal R through the first outer water-repellent portion 114 or the second outer water-repellent portion 125. In addition, if the labyrinth diameter of the labyrinth seal R is configured to be 1 mm or less, the intrusion of foreign matter such as muddy water can be further suppressed.

[0037] Even if foreign matter such as muddy water passes through the labyrinth seal R and enters the sealing device 10, the first seal lip 143A is in sliding contact with the slinger ring portion 152, so that further intrusion is suppressed and the foreign matter remains in the space portion 144. Then, the invaded foreign matter such as muddy water is discharged to the outside of the sealing device 10 by the centrifugal force and the pumping action of the air flow caused by the rotation of the bearing device 1. Furthermore, since the first water-repellent portion 113 has water repellency and its inner peripheral surface 113a is an inclined surface, foreign matter containing moisture such as muddy water is easily repelled by the first water-repellent portion 113 and discharged to the outside by rolling along the inclined surface. Since the labyrinth seal R discharges foreign matter containing moisture to the outside and is less likely to remain in the sealing device 10, the slinger member 15 is less likely to rust even if it is made of metal.

[0038] Also, there is one first seal lip 143A in sliding contact with the slinger annular portion 152, and one second seal lip 143B in sliding contact with the slinger inner circumferential cylindrical portion 151. In other words, since there are two seal lips in sliding contact with the second member 12, an increase in torque due to friction is suppressed.

[0039] In addition, since the first water-repellent portion 113 is formed of water-repellent rubber, even if the inner peripheral surface 113a is worn or damaged, the decrease in water repellency is suppressed. In addition, since the second water-repellent portion 124 has an uneven structure formed by processing the outer peripheral surface 153d of the slinger outer peripheral side cylindrical portion 153, unlike a coating agent applied to the surface of a member, it does not peel off and the decrease in water repellency is suppressed. In addition, in the seal member 14, it is sufficient that the seal cylindrical portion 141 including the first water-repellent portion 113 and the first outer water-repellent portion 114 is formed of water-repellent rubber, and the seal annular portion 142, the first seal lip 143A, and the second seal lip 143B do not have to be formed of water-repellent rubber. Since water-repellent rubber is generally an expensive elastic body, if only the seal cylindrical portion 141 constituting the labyrinth seal R and the first outer water-repellent portion 114 in the seal member 14 is made of water-repellent rubber, the manufacturing cost can be reduced compared to the case where the entire seal member 14 is manufactured from water-repellent rubber. Similarly, if the uneven structure is provided only on the portion of the slinger member 15 that constitutes the labyrinth seal R and the second outer water-repellent portion 125, manufacturing costs and time can be reduced.

[0040] <Modification of uneven structure> In the first embodiment, the second water-repellent portion 124 is formed by a concave-convex structure formed by a plurality of convex portions 124a and concave portions 124b provided on the outer peripheral surface 153d of the slinger outer peripheral side cylindrical portion 153, but is not limited thereto. For example, as shown in FIG. 3(c), a coating 124c made of a water-repellent material may be further formed on the concave-convex structure of FIG. 3(a). Also, a coating made of a water-repellent coating agent may be formed on the outer peripheral surface 153d of the slinger outer peripheral side cylindrical portion 153, and the concave-convex structure may be formed by the coating agent as shown in FIG. 3(d). Also, as shown in FIG. 3(e)(f), the concave-convex structure may be formed by providing a plurality of holes on the outer peripheral surface 153d of the slinger outer peripheral side cylindrical portion 153. In this case, the outer peripheral surface 153d becomes the convex portions 124a, and the holes become the concave portions 124b.

[0041] <Second embodiment> Next, a sealing device 10A according to a second embodiment will be described with reference to Fig. 4(a). Description of the configuration and effects of parts common to the sealing device 10 of the first embodiment will be omitted. The sealing device 10A of Fig. 4(a) differs from the first embodiment in the configuration of a seal member 14 constituting a part of the first member 11 and in the configuration of a part of the second member 12. The second member 12 includes a slinger member 15, a magnetic encoder portion 16, and a second seal cylindrical portion 17.

[0042] The seal member 14 may be formed integrally with two types of elastic bodies made of different materials by various molding methods such as two-color molding, as in the first embodiment. The seal member 14 is different from the first embodiment in that it is provided with a second seal lip 143B and a third seal lip 143C that are in sliding contact with the slinger inner circumferential cylindrical portion 151. The third seal lip 143C is a radial lip that is provided between the first seal lip 143A and the second seal lip 143B that is a grease lip, and extends toward the vehicle body and has a reduced diameter. The seal member 14 is provided with the third seal lip 143C that is a radial lip in addition to the first seal lip 143A that is an axial lip, and thus can further prevent foreign matter such as muddy water from entering the annular space S.

[0043] The second member 12 includes a second seal cylindrical portion 17 in addition to the slinger member 15 and the magnetic encoder portion 16 of the first embodiment. The second seal cylindrical portion 17 is provided adjacent to the radially outer side of the magnetic ring portion 161 of the magnetic encoder portion 16, and is formed of water-repellent rubber. The magnetic encoder portion 16 and the second seal cylindrical portion 17, which are fixed to the slinger member 15, are integrally molded by two-color molding or the like. The second seal cylindrical portion 17 is formed so as to cover the wheel side end portion 153a of the slinger outer peripheral side cylindrical portion 153 from a part of the radially outer side of the vehicle body side surface 152b of the slinger ring portion 152 through the outer peripheral surface 153d of the slinger outer peripheral side cylindrical portion 153.

[0044] Since the second seal cylindrical portion 17 is formed of water-repellent rubber, the second member 12 includes a second water-repellent portion 124 having water repellency provided on the outer peripheral surface 153d of the slinger outer peripheral side cylindrical portion 153, and a second outer water-repellent portion 125 having water repellency provided on the vehicle body side surface 152b of the slinger circular ring portion 152. The second water-repellent portion 124 and the first water-repellent portion 113 are radially opposed to each other while being close to each other, thereby forming a labyrinth seal R extending in the axial direction. In this manner, the second water-repellent portion 124 and the second outer water-repellent portion 125 of this embodiment can be configured to have water repellency due to the water-repellent rubber, unlike the uneven structure of the first embodiment. In addition, since the first water-repellent portion 113 and the second outer water-repellent portion 125 constituting the labyrinth seal R are made of water-repellent rubber, a decrease in water repellency is suppressed even if wear or damage occurs on the surface.

[0045] <Modification of the second member> Next, modified examples of the second member 12 of the sealing device 10A according to the second embodiment in FIG. 4(a) will be described with reference to FIGS. 4(b) and 4(c). In Figure 4(b), the magnetic encoder section 16 of Figure 4(a) is further formed so as to cover a portion of the radially outer side of the vehicle body side surface 152b of the slinger circular ring portion 152, through the outer peripheral surface 153d of the slinger outer peripheral cylindrical portion 153, and to cover the wheel side end portion 153a of the slinger outer peripheral cylindrical portion 153.

[0046] The magnetic encoder unit 16 includes a magnetic ring portion 161 that covers the vehicle body side surface 152b of the slinger ring portion 152, and a magnetic cylindrical portion 162 that covers the outer peripheral surface 153d and the wheel side end portion 153a of the slinger outer peripheral side cylindrical portion 153. The second member 12 includes a second water-repellent portion 124 made of water-repellent rubber that is provided to cover the outer peripheral surface 162d of the magnetic cylindrical portion 162 of the magnetic encoder unit 16. The second outer water-repellent portion 125 is provided with a concave-convex structure on the vehicle body side surface 161b of the magnetic ring portion 161 of the magnetic encoder unit 16. The second outer water-repellent portion 125 is provided to be continuous with the second water-repellent portion 124.

[0047] In FIG. 4(c), the second member 12 includes a slinger member 15 and a magnetic encoder unit 16. The magnetic encoder unit 16 includes a magnetic ring unit 161 that covers the vehicle body side surface 152b of the slinger ring unit 152, and a magnetic cylindrical unit 162 that covers the outer peripheral surface 153d of the slinger outer peripheral side cylindrical unit 153 and the wheel side end 153a. An uneven structure is formed on the vehicle body side surface 161b of the magnetic ring unit 161 of the magnetic encoder unit 16 and the outer peripheral surface 162d of the magnetic cylindrical unit 162. The second member 12 includes a second water repellent unit 124 and a second outer water repellent unit 125 with an uneven structure by providing an uneven structure on the vehicle body side surface 161b of the magnetic ring unit 161 of the magnetic encoder unit 16 and the outer peripheral surface 162d of the magnetic cylindrical unit 162.

[0048] <Third embodiment> Next, a sealing device 10B according to a third embodiment will be described with reference to FIG. 5(a). The seal member 14 of the sealing device 10B includes a first seal lip 143A, a second seal lip 143B, and a third seal lip 143C, similar to the sealing device 10A of FIG. 4(a), and has a vertical cross-sectional shape that is substantially the same as that of the seal member 14 of FIG. 4(a). The seal member 14 of FIG. 5(a) is integrally molded from one type of elastic body, unlike the first and second embodiments. That is, the seal member 14 of this embodiment is integrally formed from an elastic body of the same material as the seal cylindrical portion 141 fixed to the core cylindrical portion 131, the seal ring portion 142 fixed to the core ring portion 132, the first seal lip 143A, the second seal lip 143B, and the third seal lip 143C. A first water-repellent portion 113 having an uneven structure is formed on the inner peripheral surface of the seal cylindrical portion 141. The portion of the seal member 14 where the uneven structure is provided is not limited to the inner circumferential surface of the cylindrical seal portion 141, and the first outer water-repellent portion 114 with an uneven structure may be provided in a portion covering the vehicle body side end portion 131b of the core cylindrical portion 131. Since the water-repellent property of the first water-repellent portion 113 is constituted by the uneven structure provided on the inner circumferential surface of the cylindrical seal portion 141, the cylindrical seal portion 141 does not have to be made of water-repellent rubber.

[0049] The second member 12 includes a slinger member 15 and a magnetic encoder section 16. The slinger member 15 includes a slinger inner circumference side cylindrical section 151, which is a second cylindrical section, and a slinger ring section 152 extending radially outward from the slinger inner circumference side cylindrical section 151, and has a cross-sectional shape on one side that is substantially inverted L-shaped. In other words, the slinger member 15 of this embodiment does not include the slinger outer circumference side cylindrical section 153 of the first and second embodiments.

[0050] The magnetic encoder unit 16 is entirely made of an elastic body having both magnetism and water repellency. The magnetic encoder unit 16 includes a magnetic ring portion 161 fixed to the surface 152b of the slinger ring portion 152 facing the vehicle body. The magnetic encoder unit 16 also includes a magnetic cylindrical portion 162, which is the third cylindrical portion described above, fixed to the slinger ring portion 152 and extending from the radially outer end portion 161d of the magnetic ring portion 161 toward the wheel side in the axial direction so as to face the core cylindrical portion 131.

[0051] Since the magnetic encoder unit 16 is formed of an elastic body having water repellency, the entire outer peripheral surface of the magnetic cylindrical unit 162 becomes the second water repellent unit 124, and the entire surface of the magnetic ring unit 161 on the vehicle body side becomes the second outer water repellent unit 125. The second water repellent unit 124 and the first water repellent unit 113 having a concave-convex structure are radially opposed to each other and close to each other, thereby forming a labyrinth seal R that extends in the axial direction and has water repellency. In this way, even if the slinger member 15 does not have a slinger outer peripheral side cylindrical unit, the magnetic cylindrical unit 162 of the magnetic encoder unit 16 that extends in the axial direction from the slinger ring unit 152 can be formed. In addition, since the magnetic cylindrical unit 162 has water repellency, the sealing device 10B can be provided with a labyrinth seal R that extends in the axial direction.

[0052] Next, modified examples of the second member 12 of the sealing device 10B according to the third embodiment of Fig. 5(a) will be described with reference to Figs. 5(b) and 5(c). The configuration of the slinger member 15 is substantially the same as that of Fig. 5(a). 5(b), the magnetic encoder unit 16 is formed of magnetic rubber, and includes a magnetic ring unit 161 and a magnetic cylindrical unit 162. A second water-repellent unit 124 formed of water-repellent rubber is provided on an outer peripheral surface 162d of the magnetic cylindrical unit 162. By covering the outer peripheral surface 162d of the magnetic cylindrical unit 162 with the second water-repellent unit 124, the magnetic cylindrical unit 162, which is the third cylindrical unit, can be made water-repellent, and the amount of water-repellent rubber used can be reduced.

[0053] In FIG. 5(c), the second member 12 does not include the magnetic encoder portion 16, and includes the second seal cylindrical portion 17A formed of the slinger member 15 and water-repellent rubber. The second seal cylindrical portion 17A, which is the third cylindrical portion described above, is fixed to cover the radially outer end portion 152d of the slinger ring portion 152 and a part of the outer diameter side of both axial sides 152a, 152b, and is formed to extend toward the wheel in the axial direction. Since the second seal cylindrical portion 17A is formed of water-repellent rubber, the second member 12 includes a second water-repellent portion 124 provided on the outer circumferential surface of the second seal cylindrical portion 17A and a second outer water-repellent portion 125 provided on the surface of the second seal cylindrical portion 17A on the vehicle body side. In this way, the second member 12 is formed of an elastic body fixed to the slinger member 15 only by the above-mentioned second seal cylindrical portion 17A, so that the total amount of elastic material including the water-repellent rubber used can be reduced.

[0054] <Fourth embodiment> Next, a sealing device 10C according to a fourth embodiment will be described with reference to Fig. 6. Note that a description of the configuration and effects of parts common to the first embodiment will be omitted. The core member 13 differs from the first embodiment in that a stepped portion 131da is not formed on an outer circumferential surface 131d of a core cylindrical portion 131, but is substantially the same as the first embodiment in other respects.

[0055] The seal member 14 is formed such that the seal ring portion 142 covers the wheel side surface 132a, the vehicle body side surface 132b, and the radially inner end portion 132c of the core ring portion 132. An annular protrusion 142e that protrudes radially outward is formed on the outer circumferential surface of the seal ring portion 142. The annular protrusion 142e is interposed in a compressed state between the wheel side end portion 131a of the core cylindrical portion 131 and the inner circumferential surface 2c of the outer ring 2, and can prevent foreign matter such as muddy water that has traveled between the outer circumferential surface 131d of the core cylindrical portion 131 and the inner circumferential surface 2c of the outer ring 2 from further intruding.

[0056] The first member 11 is provided with a first water-repellent portion 113 having an uneven structure formed on the inner peripheral surface 131c of the core cylindrical portion 131. Note that a first outer water-repellent portion 114 may be provided by forming an uneven structure on the end portion 131b of the core cylindrical portion 131 on the vehicle body side.

[0057] The second member 12 includes the slinger member 15, and a second water-repellent portion 124 having an uneven structure is formed on the outer peripheral surface 153d of the slinger outer peripheral cylindrical portion 153. Also, a second outer water-repellent portion 125 having an uneven structure is formed on the vehicle body side surface 152b of the slinger circular ring portion 152. In this manner, the second member 12 does not include a magnetic encoder portion 16.

[0058] Both the first water-repellent portion 113 and the second water-repellent portion 124 are formed with a concave-convex structure. This concave-convex structure is formed on the outer peripheral surface 153d of the slinger outer peripheral cylindrical portion 153 and the vehicle body side surface 152b of the slinger ring portion 152 by physical processing such as laser processing, so it does not peel off and the decrease in water repellency is suppressed. In addition, since foreign matter containing moisture is discharged to the outside by the labyrinth seal R and is unlikely to remain in the sealing device 10C, even if the core member 13 and the slinger member 15 are made of metal, they are unlikely to rust. Note that the core member 13 and the slinger member 15 are preferably formed of a metal material that is resistant to rust, such as SUS.

[0059] <Fifth embodiment> Next, a sealing device 20 according to a fifth embodiment will be described with reference to Fig. 7. Fig. 7 is an enlarged view of a portion Y in Fig. 1. Simply put, the sealing device 20 in Fig. 7 is the sealing device 10C in Fig. 6 reversed left and right and attached to the end of the annular space S on the wheel side. Therefore, detailed description of the shapes of the members constituting the sealing device 20 will be omitted. The sealing device 20 is attached by fitting the core cylindrical portion 231, which is the first cylindrical portion, to the inner peripheral surface 2c of the outer ring 2, and the slinger inner peripheral side cylindrical portion 251, which is the second cylindrical portion, to the outer peripheral surface 30a of the hub wheel main body 30.

[0060] The first member 21 includes a core member 23 and a seal member 24. The core member 23 includes a core cylindrical portion 231 and a core ring portion 232 extending radially inward from the core cylindrical portion 231. The seal member 24 includes a first seal lip 243A and a second seal lip 243B that extend toward and slide against the second member 22. Meanwhile, the second member 22 includes a slinger member 25. The slinger member 25 includes a slinger inner circumference side cylindrical portion 251, a slinger ring portion 252 extending radially outward from the slinger inner circumference side cylindrical portion 251, and a slinger outer circumference side cylindrical portion 253 that is a third cylindrical portion that faces the core cylindrical portion 231 in the radial direction.

[0061] A first water-repellent portion 213 having an uneven structure is formed on the inner peripheral surface 231c of the core cylindrical portion 231. A second water-repellent portion 224 and an outer water-repellent portion 225 having an uneven structure are continuously formed on the outer peripheral surface 253d of the slinger outer peripheral side cylindrical portion 253 and the wheel side surface 252a of the slinger ring portion 252. The second water-repellent portion 224 and the outer water-repellent portion 225 are applied to the outer peripheral surface 253d of the slinger outer peripheral side cylindrical portion 253 and the wheel side surface 252a of the slinger ring portion 252 by laser processing or the like, so they do not peel off and a decrease in water repellency is suppressed.

[0062] In the sealing device 20, the first water-repellent portion 213 and the second water-repellent portion 224 are adjacent to each other in the radial direction, thereby forming a labyrinth seal R that extends in the axial direction and has water-repellent properties. The sealing device 20 prevents foreign matter such as muddy water from entering by the labyrinth seal R. Foreign matter such as muddy water discharged from the sealing device 20 passes through an opening between the hub flange 32 and the outer ring 2 and is discharged to the external space.

[0063] The configuration of the sealing device is not limited to the above, and may be a combination or rearrangement of the configurations of each embodiment. In addition, for example, in the first water-repellent portion, the first outer water-repellent portion, the second water-repellent portion, and the second outer water-repellent portion, those that have water repellency due to an uneven structure may have water repellency by coating with a water-repellent substance instead of the uneven structure. Conversely, the portion covered with a water-repellent substance may have water repellency by providing an uneven structure instead of the water-repellent substance. In addition, the portion where the uneven structure is provided is not limited to the area indicated by the dashed line A in the figure. Although a seal lip is provided in the sealing device of each embodiment, it is not necessary to provide one as long as a predetermined sealing function can be ensured.

[0064] In this specification, the term "water repellency" is used for convenience, such as "first water repellent portion," "second water repellent portion," and "water repellency." Therefore, the first water repellent portion, the second water repellent portion, etc. are not limited to those having a water contact angle of 90 degrees or more, and may have a property generally called "hydrophobic" or "hydrophilic" of less than 90 degrees or even less than 30 degrees. With such a small water contact angle, water that comes into contact with the first water repellent portion, the second water repellent portion, etc. flows smoothly over the first water repellent portion, the second water repellent portion, etc., and is discharged to the outside of the sealing device. [Explanation of symbols]

[0065] 1 Bearing device 2 Outer ring (outer component) 2c Inner surface 3 Hub ring (inner part) 30 Hub body 30a Outer surface 4 Inner ring member (inner member) 4b Outer surface 5 Inner ring (inner member) 10,10A,10B,10C,20 Sealing device 11,21 First member 113,213 First water-repellent section 131, 231 Core cylindrical portion (first cylindrical portion) 12,22 Second member 15,25 Slinger member 151,251 Slinger inner cylindrical part (second cylindrical part) 152,252 Slinger ring part 153,253 Slinger outer cylindrical part (third cylindrical part) 17A Second seal cylinder part (third cylinder part) 124,224 Second water-repellent section 143A, 243A First seal lip 143B, 243B Second seal lip

Claims

1. A sealing device for sealing an annular space formed between an outer member and an inner member which rotate relative to each other, comprising: a first member having an inner circumferential surface of the outer member fitted with a first cylindrical portion, and a second member having an outer circumferential surface of the inner member fitted with a second cylindrical portion, the first member includes a first water-repellent portion provided on an inner circumferential surface of the first cylindrical portion and having water-repellent properties; the second member includes a third cylindrical portion radially opposed to the first cylindrical portion, and a second water-repellent portion provided on at least an outer circumferential surface of the third cylindrical portion and having water repellency; A sealing device characterized in that the first water-repellent portion and the second water-repellent portion are disposed opposite and adjacent to each other to form a labyrinth seal extending in the axial direction.

2. In claim 1, A sealing device characterized in that the first water-repellent portion is an uneven structure provided on the inner surface of the first cylindrical portion.

3. In claim 1, A sealing device, characterized in that the first water-repellent portion is made of a water-repellent elastic material.

4. In any one of claims 1 to 3, A sealing device characterized in that the second water-repellent portion is an uneven structure provided on the outer peripheral surface of the third cylindrical portion.

5. In any one of claims 1 to 3, A sealing device, characterized in that the second water-repellent portion is made of a water-repellent elastic material.

6. In any one of claims 1 to 3, The second member includes a slinger member having a slinger ring portion extending radially outward from the second cylindrical portion, A sealing device characterized in that the third cylindrical portion is composed of an elastic body fixed to the slinger ring portion and extending in the axial direction so as to face the first cylindrical portion.

7. In any one of claims 1 to 3, A sealing device characterized in that an outer water-repellent portion having water-repellent properties is provided on at least one of the axial outer end face of the first cylindrical portion and the axial outer surface of the portion of the second member that connects to the third cylindrical portion.

8. In any one of claims 1 to 3, The second member includes a slinger member having a slinger ring portion extending radially outward from the second cylindrical portion, A sealing device characterized in that the first member has a first seal lip extending toward and in sliding contact with the slinger ring portion, and a second seal lip extending toward and in sliding contact with the second cylindrical portion.

Images