Sealing device

Abstract

A hub seal (1) is provided with a seal body (3) and a slinger (4). The seal body (3) is provided with a reinforcing ring (10) and an elastic body part (20). The slinger (4) is provided with a flange part (31) and a cylindrical part (32). An outer cylindrical surface (3a), which is a surface of cylinder form, is formed on the seal body (3). The elastic body part (20) has a side lip (21) farther to the inner periphery than the outer cylindrical surface (3a). The cylindrical part (32) of the slinger (4) is positioned farther to the outer periphery than the side lip (21) and has at the inner end an annular weir part (33) that extends toward the outer periphery. The outer cylindrical surface (3a) faces the cylindrical part (32) from the outer peripheral side. Between the outer cylinder surface (3a) and an end (33a) of the weir part (33), there is formed a first gap (S1) of which the radial width (W1) is less than the radial width (W2) of a second gap (S2) formed between the outer cylinder surface (3a) and a portion of the weir part (33) that faces the outer cylinder surface (3a) and that is not the end (33a).

Description

sealing device

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

[0002] Hub bearings in vehicles, such as automobiles, 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 the lubricant inside the hub bearing and prevent foreign matter from entering the interior. Because hub bearings are in harsh environments directly exposed to foreign matter such as rainwater, muddy water, and dust, improved sealing performance against foreign matter is required for the housing seal. Furthermore, due to demands for lower fuel consumption, the hub seal is required to reduce the sliding resistance (torque resistance) that the seal lip applies to the hub bearing. While increasing the number of seal lips is considered to improve the sealing performance of the hub seal, this increases the torque resistance of the hub seal. For this reason, a hub seal has been proposed that improves sealing performance against foreign matter without increasing the torque resistance of the hub seal by forming a labyrinth seal using a slinger (see, for example, Patent Document 1).

[0003] JP 2010-91036 A

[0004] As described above, hub bearings are used in harsh environments where they are directly exposed to foreign matter such as rainwater, muddy water, and dust. Therefore, even in hub seals with labyrinth seals such as the one disclosed in Patent Document 1, foreign matter may enter through the labyrinth seal. In particular, liquid foreign matter such as rainwater, muddy water, or dust-containing rainwater or muddy water may enter through the labyrinth seal. For this reason, there is a demand for hub seals with further improved sealing performance against liquid foreign matter. As such, there is a demand for a configuration that can improve sealing performance against liquid foreign matter 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.

[0005] 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 improve sealing performance against liquid foreign matter.

[0006] In order to achieve the above object, a sealing device according to the present invention is a sealing device for sealing a gap between an outer peripheral side member and an inner peripheral side member at least partially surrounded by the outer peripheral side member, which are rotatable relative to each other about an axis, and the sealing device includes a sealing device main body fixed to the outer peripheral side member, and a slinger fixed to the inner peripheral side member, the sealing device main body includes a reinforcing ring annular about the axis, and an elastic body portion attached to the reinforcing ring and formed from an elastic body annular about the axis, the slinger includes an annular portion which is an annular portion about the axis and extends along a radial direction, and a tubular portion which is a tubular portion extending from an outer peripheral end of the annular portion toward one side in the axial direction along the axis, and the sealing device main body includes a reinforcing ring annular about the axis, and an elastic body portion attached to the reinforcing ring and formed from an elastic body annular about the axis, the slinger includes a reinforcing ring annular about the axis and an elastic body portion formed from an elastic body annular about the axis, the reinforcing ring An outer cylindrical surface is formed, which is a cylindrical surface extending from the slinger, and the elastic body portion has a side lip that extends toward the other side in the axial direction, inner peripherally of the outer cylindrical surface, and is adapted to contact the slinger, and the cylindrical portion of the slinger is positioned outer peripherally of the side lip, and the cylindrical portion of the slinger has a dam portion, which is an annular portion extending toward the outer peripheral side, at the end of one side, and the outer cylindrical surface of the sealing device main body faces at least a portion, including the end of the dam portion, of the cylindrical portion of the slinger from the outer peripheral side, and a first gap narrower than the radial width of a second gap between the outer cylindrical surface and the portion of the cylindrical portion that is not the end of the dam portion facing the outer cylindrical surface is formed.

[0007] In a sealing device according to one embodiment of the present invention, the radial width of the first gap is a width that forms a labyrinth seal against liquid foreign matter, and the radial width of the second gap is a width that does not form a labyrinth seal against liquid foreign matter.

[0008] In the sealing device according to one aspect of the present invention, foreign matter that flows into the second gap can be discharged from the second gap.

[0009] In a sealing device according to one aspect of the present invention, the dam portion has a dam surface that extends from the end toward the inner circumference and is a surface facing the other side that is annular around the axis, and the cylindrical portion has an inner cylindrical surface that is a cylindrical surface facing the outer circumference and extends from the inner end of the dam surface toward the other side.

[0010] In the sealing device according to one aspect of the present invention, the inner cylindrical surface of the cylindrical portion increases in diameter toward the one side in the axial direction.

[0011] In the sealing device according to one aspect of the present invention, the end of the dam portion is a surface facing the outer periphery of an annular shape around the axis.

[0012] In the sealing device according to one aspect of the present invention, the elastic body portion forms the outer cylindrical surface.

[0013] In a sealing device according to one aspect of the present invention, the elastic body portion has an intermediate lip extending toward the slinger on the inner peripheral side of the side lip.

[0014] In a sealing device according to one aspect of the present invention, the elastic body portion has a grease lip that extends from the one side beyond the intermediate lip and contacts the slinger.

[0015] In the sealing device according to one aspect of the present invention, the one side is the inner side, which is the outer sealing device.

[0016] In the sealing device according to one aspect of the present invention, the one side is an outer side, and is an inner side sealing device.

[0017] The sealing device according to the present invention can improve the sealing performance against liquid foreign matter.

[0018] Fig. 1 is a cross-sectional view showing a cross section taken along a plane including the axis of an example hub bearing. Fig. 2 is a partially enlarged cross-sectional view of the vicinity of the hub seal according to the first embodiment of the present invention in Fig. 1. Fig. 3 is a partially enlarged cross-sectional view of the hub seal in Fig. 2. Fig. 4 is a cross-sectional view of a modified example of the hub seal shown in Fig. 2. Fig. 5 is a partially enlarged cross-sectional view of another modified example of the hub seal shown in Fig. 2. Fig. 6 is a partially enlarged cross-sectional view of the vicinity of the hub seal according to the second embodiment of the present invention in Fig. 1. Fig. 7 is a cross-sectional view of a modified example of the hub seal shown in Fig. 6.

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] 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 showing a cross section 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 supports a wheel in an axle or suspension system so that the wheel can rotate freely. 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.

[0021] 1 , the hub bearing 100 specifically includes an annular outer ring 101 serving as an outer peripheral member and having a central axis or approximate central axis along the 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 the axis x, and a plurality of bearing balls (rolling elements) 103 disposed between the outer ring 101 and the inner ring 102. When the hub bearing 100 is in use and mounted on a vehicle or the like, the outer ring 101 is fixed and the inner ring 102 is rotatable relative to the outer ring 101. The inner ring 102 specifically includes an inner ring member 104 and a hub ring 105. The hub ring 105 has a tubular or approximate cylindrical shaft portion 105a extending along the axis x and a wheel mounting flange 105b. The wheel mounting flange 105b extends from one end of the shaft portion 105a toward the outer periphery in a disk-like shape. A brake disc rotor (not shown) and a tire wheel (not shown) are attached to the shaft portion 105a using a plurality of hub bolts (not shown). The shaft portion 105a and the wheel mounting flange 105b are smoothly connected on the inner periphery. A transition portion 105c, where the shaft portion 105a and the wheel mounting flange 105b join on the inner periphery, has an arc-shaped or smoothly curved profile in a cross section taken along a plane including the axis x. The inner ring member 104 is fitted to the inner end of the shaft portion 105a of the hub ring 105 to hold the bearing balls 103 in the gap 100a between the outer ring 101 and the inner ring 102. The bearing balls 103 are held in the gap 100a between the outer ring 101 and the inner ring 102 by a cage 106.

[0022] The outer ring 101 has a through hole 107 extending in the direction of the axis x, and the shaft portion 105a of the hub ring 105 of the inner ring 102 is inserted into this through hole 107, forming an annular gap 100a extending along the axis x between the shaft portion 105a and the through hole 107. As described above, the bearing balls 103 are accommodated within this gap 100a and held by the cage 106, and a lubricant is applied or injected into the gap 100a. A sealing device 1 is attached to an inner opening 101a of the outer ring 101, which forms an opening that opens the gap 100a between the inner ring member 104, the shaft portion 105a, and the through hole 107 on the inside. Meanwhile, a sealing device 2 is attached to an outer opening 101b of the outer ring 101, which forms an opening that opens the gap 100a on the outside.

[0023] The sealing device 1 is a sealing device according to a first embodiment of the present invention and is an inner hub seal. Meanwhile, the sealing device 2 is a sealing device according to a second embodiment of the present invention and is an outer hub seal. The sealing devices 1 and 2 seal the shaft portion 105a of the hub wheel 105 and the gap 100a between the inner ring member 104 and the outer ring 101, preventing lubricant in the gap 100a from leaking to the outside and preventing foreign matter such as rainwater, muddy water, and dust from entering the gap 100a from the outside. 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, the sealing device applied to the hub bearing is also referred to as a hub seal.

[0024] Next, we will explain the hub seal 1 according to a first embodiment of the present invention. Figure 2 is a partially enlarged cross-sectional view of the vicinity of the hub seal 1 in Figure 1, and Figure 3 is a partially enlarged cross-sectional view of the hub seal 1 in Figure 2. 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, the seal body 3 and slinger 4 are attached to the hub bearing 100 so that they are in a predetermined relative position.

[0025] As shown in Figures 2 and 3, 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 annular about the axis x, and an elastic body portion 20 attached to the reinforcing ring 10 and formed of an elastic body annular about the axis x. The slinger 4 includes a flange portion 31 as an annular portion that is an annular portion extending radially about the axis x, and a cylindrical portion 32 that is a cylindrical portion extending from the outer peripheral end of the flange portion 31 along the axis x toward one side (outside) in the axis x direction. The seal body 3 includes an outer cylindrical surface 3a that is an annular cylindrical surface extending along the axis x. The elastic body portion 20 has a side lip 21 that extends toward the other side (inward) in the axis x direction, located radially inward of the outer cylindrical surface 3a, and is adapted to contact the slinger 4. The cylindrical portion 32 of the slinger 4 is positioned more radially outward than the side lip 21. The cylindrical portion 32 of the slinger 4 has a dam portion 33, which is an annular portion extending radially outward, at its outer end. The outer cylindrical surface 3a of the seal body 3 faces at least a portion, including the end 33a, of the dam portion 33 of the cylindrical portion 32 of the slinger 4 from the radially outward side. Between the outer cylindrical surface 3a and the end 33a of the dam portion 33, an annular first gap S1 is formed. The radial width W1 is narrower than the radial width W2 of an annular second gap S2 formed between the outer cylindrical surface 3a and the portion of the cylindrical portion 32 that is not the end 33a of the dam portion 33 facing the outer cylindrical surface 3a. The configuration of the hub seal 1 will be described in detail below.

[0026] As shown in FIG. 1, the outer side refers to the side indicated by arrow a in the direction of axis x, while the inner 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 outer side is the wheel side, and the inner side is the body 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, that is, the side indicated by arrow c in FIG. 1, and the inner peripheral side refers to the side of the hub bearing 100 that is radially closer to the axis x, that is, the side indicated by arrow d in FIG. The axis x of the hub seal 1 mounted on the hub bearing 100 coincides or nearly 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.

[0027] As shown in Fig. 2, for example, the reinforcing ring 10 is an annular metal member whose central axis or approximate central axis is the axis x, and is formed to be press-fitted into a through hole 107 of the outer ring 101 of the 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 fitting portion 11, a lip support portion 12 that bends inward from the outer end of the fitting portion 11 and extends toward the inner circumference, and an annular plate-shaped flange portion 13 that extends from the inner end of the fitting portion 11 toward the outer circumference.

[0028] The fitting portion 11 is, for example, a cylindrical or approximately cylindrical portion with the axis x as its central axis or approximately central axis. The outer peripheral surface 11a, which is the outer peripheral surface, is formed so as to be press-fitted into the inner opening 101a of the outer ring 101 and fitted to its inner peripheral surface 101c, as shown in FIGS. 1 and 2 . The lip support portion 12 is shaped so that, for example, the side lip 21 and the intermediate lip 22 and grease lip 23 (described later) are positioned at desired positions relative to the slinger 4 in the hub seal 1. As shown in FIG. 2 , the lip support portion 12 has a return portion 12a and a lip flange portion 12b. The return portion 12a is, for example, a portion that bends from the outer end of the fitting portion 11 and returns inward. The lip flange portion 12b is, for example, an annular plate-shaped portion that extends inward from the inner end of the return portion 12a. 2, the flange portion 13 is an annular plate-shaped portion extending radially from the axis x at or approximately at the center. The reinforcing ring 10 is formed as an integral member, for example, by pressing or forging a metal plate, and the fitting portion 11, lip support portion 12, and flange portion 13 are each integrally formed from the same material and are continuous. Examples of metal materials for the reinforcing ring 10 include stainless steel and SPCC (cold-rolled steel).

[0029] 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 FIG. 2 . In addition to the side lips 21, the elastic body portion 20 also has, for example, an intermediate lip 22 and a grease lip 23. The side lips 21, the intermediate lip 22, and the grease lip 23 are each annular seal lips around the axis x. As shown in FIG. 2 , for example, the intermediate lip 22 extends inward from a position radially inward of the side lips 21 and contacts the slinger 4. As shown in FIG. 2 , for example, the grease lip 23 extends outward from the intermediate lip 22 and contacts the slinger 4. The side lips 21 and the intermediate lip 22 contact the flange portion 31 of the slinger 4 to prevent foreign matter from entering the gap 100a of the hub bearing 100 and to prevent lubricant from leaking from the gap 100a. The grease lip 23 also prevents the lubricant from leaking out from the gap 100 a of the hub bearing 100 .

[0030] The elastic body portion 20 also has, for example, a base portion 24. As shown in FIG. 2 , the intermediate lip 22 and the grease lip 23 each extend from an end portion on the inner circumferential side of the base portion 24. As shown in FIG. 2 , the side lip 21 extends from the base portion 24 radially away from the intermediate lip 22, on the outer circumferential side of the intermediate lip 22. The base portion 24 is a portion of the elastic body portion 20 that extends over the flange portion 13, the fitting portion 11, and the lip support portion 12 of the reinforcing ring 10 and covers the inner surface of the reinforcing ring 10. As shown in FIGS. 2 and 3 , the base portion 24 has an outer peripheral facing portion 24a that is a cylindrical portion extending along the fitting portion 11 of the reinforcing ring 10, and the outer cylindrical surface 3a described above is formed on the outer peripheral facing portion 24a of the base portion 24. The outer cylindrical surface 3a is, for example, a cylindrical surface or an approximately cylindrical surface with the axis x as its central axis or approximately its central axis. The outer cylinder surface 3 a is not limited to a surface that describes a straight line parallel to the axis x in a cross section taken along a plane including the axis x. The outer cylinder surface 3 a may, for example, be a surface that describes a straight line inclined with respect to the axis x in a cross section taken along a plane including the axis x, a curved surface, or a surface that describes a line that is a combination of a straight line and a curved line. Specifically, for example, the outer cylinder surface 3 a may be a conical surface or an approximately conical surface whose diameter increases as it extends inward in the direction of the axis x, with the axis x as its central axis or approximately its central axis.

[0031] As shown in Fig. 2, the side lip 21 specifically extends inward from the base portion 24 in an annular shape with the axis x as its central axis or approximately central axis. Also, 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 21 is formed so that its tip contacts the flange portion 31 of the slinger 4 with a predetermined interference. As shown in Fig. 2, the side lip 21 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] As shown in FIG. 2 , the intermediate lip 22 extends inward from the base portion 24 in an annular shape with the axis x as its central axis or approximately central axis. Furthermore, when the hub seal 1 is in use, the intermediate lip 22 is formed so that its tip contacts the flange portion 31 of the slinger 4 with a predetermined interference. The intermediate lip 22 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. The intermediate lip 22 may extend parallel to the side lips 21. Alternatively, as shown in FIG. 2 , the intermediate lip 22 may not be parallel to the side lips 21, but may be inclined more gently with respect to the axis x than the side lips 21. Conversely, the intermediate lip 22 may be inclined more sharply with respect to the axis x than the side lips 21. As shown in FIG. 2 , the grease lip 23 extends outward and inward from the base portion 24 in an annular shape with the axis x as its central axis or approximately central axis. The grease lip 23 is formed so that when the hub seal 1 is in use, its tip contacts the fitting portion 34 of the slinger 4 from the outer periphery with a predetermined interference.

[0033] Furthermore, as shown in FIG. 2 , the elastic body portion 20 is formed with a ring-shaped protrusion 25. The ring-shaped protrusion 25 is a ring-shaped protrusion around the axis x that protrudes inward and is located radially outward of the outer cylindrical surface 3a. As shown in FIG. 2 , the ring-shaped protrusion 25 extends from a portion of the base portion 24 along the flange portion 13 of the reinforcing ring 10. As shown in FIGS. 2 and 3 , when the hub seal 1 is in use, the ring-shaped protrusion 25 is located radially outward of the second gap S2, and its inner end 25a, which is its inner tip, is located inside the inner opening S2a of the second gap S2. Furthermore, the ring-shaped protrusion 25 protrudes obliquely inward and outward from the outer peripheral end of the base portion 24, for example.

[0034] As shown in FIG. 2 , the elastic body portion 20 also has a gasket portion 26, which is an annular portion that protrudes outward, located radially outward of the annular protrusion portion 25. As shown in FIG. 2 , the gasket portion 26 is formed so as to contact the outer peripheral surface 101d of the inner opening 101a of the outer ring 101 when the hub seal 1 is in use. As shown in FIG. 2 , the gasket portion 26 is also formed so as to cover the outer peripheral end of the flange portion 13 of the reinforcing ring 10. As shown in FIG. 2 , the elastic body portion 20 also has a gasket portion 27 that at least partially covers the outer surface of the flange portion 13 of the reinforcing ring 10. The gasket portion 27 extends annularly around the axis x and continues to the inner end of the gasket portion 26. As shown in FIG. 2 , the gasket portion 27 is formed so as to contact the inner end surface 101e of the inner opening 101a of the outer ring 101 when the hub seal 1 is in use.

[0035] The elastic body portion 20 is integrally attached to the reinforcing ring 10, and the above-mentioned side lip 21, intermediate lip 22, grease lip 23, base portion 24, ring protrusion 25, gasket portion 26, and gasket portion 27 are each parts of the elastic body portion 20 integrally formed from the same material and are continuous. 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). The elastic body portion 20 is integrally attached to the reinforcing ring 10 mainly at the base portion 24.

[0036] 1 and 2, the slinger 4 is formed to be press-fitted into an inner ring member 104 of an inner ring 102 of the hub bearing 100 and fitted to the inner ring member 104. As shown in FIG. 2, for example, the slinger 4 has a flange portion 31 and a cylindrical portion 32, as well as a fitting portion 34 formed to face the cylindrical portion 32 with the flange portion 31 interposed therebetween.

[0037] As shown in FIG. 2 , the fitting portion 34 is a cylindrical or approximately cylindrical portion with the axis x as its central axis or approximate central axis, and is formed to be fitted onto the outer circumferential surface 104a of the inner ring member 104. The contact surface 34a, which is the surface facing the outer circumferential side of the fitting portion 34, is a cylindrical or approximately cylindrical surface with the axis x as its central axis or approximate central axis, as shown in FIG. 2 . The flange portion 31 is a disc-shaped or approximately disc-shaped portion extending radially with the axis x as its central axis or approximate central axis, and forms an annular portion protruding radially from the outer circumferential surface 104a of the inner ring member 104, as shown in FIG. 2 . The contact surface 31a, which is the surface facing the inside of the flange portion 31, is, for example, a surface extending on a plane parallel or approximately parallel to a plane perpendicular to the axis x.

[0038] As shown in Figures 2 and 3, the tubular portion 32 of the slinger 4 is, for example, a substantially cylindrical portion extending outward from the outer peripheral end of the flange portion 31 and having a central axis or approximate central axis along the axis x. As shown in Figure 3, the tubular portion 32 has an inner tubular surface 32a facing the outer peripheral side. The inner tubular surface 32a is, for example, a cylindrical surface or an approximate cylindrical surface having the axis x as its central axis or approximate central axis. As described above, the inner end of the tubular portion 32 is provided with an annular dam portion 33 that protrudes outward. As shown in Figure 3, for example, the dam portion 33 is provided outside the inner tubular surface 32a and is connected to the outer end of the inner tubular surface 32a. As shown in Figure 3, the dam portion 33 protrudes outward beyond the inner tubular surface 32a and has a dam surface 33b between the end 33a and the inner tubular surface 32a. The weir surface 33b is an annular inward-facing surface around the axis x that extends from the end 33a to the inner periphery. Furthermore, as shown in FIG. 3 , the weir portion 33 has a side surface 33c that is an annular surface facing outward. The side surface 33c is a surface facing away from the weir surface 33b. The end 33a of the weir portion 33 is the tip of the weir portion 33, and as shown in FIG. 3 , for example, is an annular surface facing the outer periphery, specifically, for example, a cylindrical surface or a substantially cylindrical surface with the axis x as the central axis or substantially the central axis. Furthermore, the weir surface 33b and the side surface 33c are specifically, for example, surfaces that extend on a plane parallel or substantially parallel to a plane perpendicular to the axis x.

[0039] As shown in Fig. 3, the end 33a of the weir portion 33 faces the outer cylindrical surface 3a of the seal body 3 from the inner circumferential side in the radial direction, and an annular first gap S1 is formed between the end 33a of the weir portion 33 and the outer cylindrical surface 3a. Also, as shown in Fig. 3, the inner cylindrical surface 32a of the cylindrical portion 32 faces the outer cylindrical surface 3a from the inner circumferential side in the radial direction, and an annular second gap S2 is formed between the inner cylindrical surface 32a of the cylindrical portion 32 and the outer cylindrical surface 3a. As shown in Fig. 3, the outer cylindrical surface 3a faces the end 33a of the weir portion 33 and the entire inner cylindrical surface 32a of the cylindrical portion 32 in the radial direction. The outer cylindrical surface 3a may also face the end 33a of the weir portion 33 and a portion of the inner cylindrical surface 32a of the cylindrical portion 32 in the radial direction.

[0040] As shown in FIG. 3 , the radial width of the first gap S1 is W1. Meanwhile, the radial width of the second gap S2 is W2. The width W1 of the first gap S1 is narrower than the width W2 of the second gap S2. The gap width is a predetermined value, such as the width at a specific position of the gap (such as the position where the gap is maximum or minimum) or the average value of the gap widths at a predetermined number of positions. Also, as shown in FIG. 3 , the length of the first gap S1 in the axial x direction is L1. Meanwhile, the length of the second gap S2 in the axial x direction is L2. The length L1 of the first gap S1 corresponds to the width of the end 33a in the axial x direction, and the length L1 of the first gap S1 and this width of the end 33a are the same value. Meanwhile, the length L2 of the second gap S2 corresponds to the width of the inner cylindrical surface 32a in the axial x direction, and the length L2 of the second gap S2 and this width of the inner cylindrical surface 32a are the same value.

[0041] Specifically, the width W1 and length L1 of the first gap S1 are set to form a labyrinth seal against liquid foreign matter. In this way, the first gap S1 is a labyrinth gap S1. The liquid foreign matter may be rainwater, muddy water, dust-containing rainwater, muddy water, or other liquid foreign matter. The labyrinth seal formed by the gap creates a resistance effect that prevents liquid foreign matter from entering the gap and resists the liquid foreign matter from entering the gap. The width W1 and length L1 of the labyrinth gap S1 are set to values ​​that create the above-mentioned resistance effect against liquid foreign matter to which the hub seal 1 is expected to be exposed depending on the application of the hub seal 1. The width W1 and length L1 of the labyrinth gap S1 are set, for example, based on the physical properties of the liquid foreign matter to which the hub seal 1 is expected to be exposed depending on the application of the hub seal 1. The physical properties of the liquid foreign matter include, for example, the viscosity and surface tension of the liquid foreign matter, and the size of solid foreign matter contained in the liquid foreign matter. The above-mentioned resistance effect can be confirmed, for example, by a test under a simulated condition in which the hub seal 1 is in use.

[0042] On the other hand, the width W2 and length L2 of the second gap S2 are set so as not to form a labyrinth seal against liquid foreign matter. The second gap S2 is configured so that liquid foreign matter flowing into the second gap S2 can be discharged from the second gap S2, and the second gap S2 serves as a discharge gap S2. Specifically, as described above, the discharge gap S2 is defined by the inner cylindrical surface 32a of the cylindrical portion 32, the weir surface 33b of the weir portion 33, the labyrinth gap S1, and the outer cylindrical surface 3a. Downstream of the flow of foreign matter flowing into the discharge gap S2, the discharge gap S2 is blocked by the weir surface 33b and the labyrinth gap S1. Therefore, foreign matter that flows into the discharge gap S2 mainly moves downstream along the inner cylindrical surface 32a of the cylindrical portion 32 and is repelled by the weir surface 33b and the labyrinth gap S1. The width W2 and length L2 of the discharge gap S2 are set so as not to form a labyrinth seal against liquid foreign matter. Specifically, the width W2 and length L2 of the discharge gap S2 are set so that liquid foreign matter bounced off the weir surface 33b and the labyrinth gap S1 can flow toward the opening S2a of the discharge gap S2. The width W2 and length L2 of the discharge gap S2 are preferably set so as to prevent liquid foreign matter bounced off the weir surface 33b and the labyrinth gap S1 from interfering with foreign matter flowing into the discharge gap S2 and moving downstream. In this way, the discharge gap S2 has a discharge function of discharging liquid foreign matter that flows into the discharge gap S2 and bounces off the weir surface 33b and the labyrinth gap S1 from the opening S2a to the outside of the discharge gap S2. The discharge gap S2 also has a discharge function for foreign matter other than liquid foreign matter. The discharge gap S2 does not necessarily have to have a discharge function for foreign matter that is not liquid. This discharge function can be confirmed, for example, by testing in a state simulating the actual use state of the hub seal 1.

[0043] As shown in FIG. 3 , the side surface 33c of the weir portion 33 faces the opposing portion 24b, which is a portion of the base portion 24 extending along the lip flange portion 12b of the reinforcing ring 10, from the inside in the axial x direction. An annular gap S3 is formed between the side surface 33c of the weir portion 33 and the opposing portion 24b of the base portion 24. The gap S3 communicates with the labyrinth gap S1. Similar to the labyrinth gap S1, the gap S3 forms a labyrinth seal against liquid foreign matter. Specifically, for example, the width W3 of the gap S3 in the axial x direction and the radial length L3 of the gap S3 are set to form a labyrinth seal against liquid foreign matter. The length L3 of the gap S3 corresponds to the radial width of the side surface 33c, and the length L3 of the gap S3 is the same value as this width of the side surface 33c. In this case, the labyrinth gap S1 and the gap S3 form a single labyrinth seal. The gap S3 may be a gap that does not form a labyrinth seal against liquid foreign matter.

[0044] The slinger 4 is also configured to fit tightly against the inner ring member 104. Specifically, the fitting portion 34 of the slinger 4 and the inner ring member 104 are configured to fit tightly against each other so that no gap through which foreign matter can pass is formed between the fitting portion 34 and the inner ring member 104. The slinger 4 and the inner ring member 104 do not have to be in tight contact as described above. In this case, for example, an annular gasket may be provided between the slinger 4 and the inner ring member 104 to prevent foreign matter from entering the gap 100a between the outer ring 101 and the inner ring 102 through the gap between the slinger 4 and the inner ring member 104. For example, as shown in FIG. 4 , an annular gasket 5 made of an elastic material may be provided on the inner circumferential surface 31b of the flange portion 31 of the slinger 4, contacting the outer circumferential surface 104a of the inner ring member 104. The gasket 5 may also function as an encoder. 4, the gasket 5 of the hub seal 1 is covered from the outer periphery by the outer cylindrical surface 3a in the direction of the axis x. Note that the gasket 5 of the hub seal 1 may not be covered from the outer periphery by the outer cylindrical surface 3a in the direction of the axis x, but may protrude inward beyond the outer cylindrical surface 3a.

[0045] Furthermore, the inner cylindrical surface 32a of the cylindrical portion 32 of the slinger 4 may extend at an angle with respect to the axis x direction, as shown in Fig. 5 . Specifically, for example, as shown in Fig. 5 , the cylindrical portion 32 of the slinger 4 may be formed in a truncated cone shape. That is, as shown in Fig. 5 , the cylindrical portion 32 of the slinger 4 may be a conical or approximately conical cylindrical portion whose diameter increases outward in the axis x direction, and the inner cylindrical surface 32a may be a conical or approximately conical surface whose central axis is the axis x and whose diameter increases outward in the axis x direction. In this way, if the cylindrical portion 32 of the slinger 4 is a truncated cone shape and the inner cylindrical surface 32a of the cylindrical portion 32 is a conical surface whose diameter increases outward from the flange portion 31, the discharge action of the discharge gap S2 can be further strengthened.

[0046] The slinger 4 is integrally formed, for example, by pressing or forging a metal plate of uniform thickness, and the cylindrical portion 32, flange portion 31, and fitting portion 34 are integrally formed parts of the slinger 4. Examples of the metal material for the slinger 4 include stainless steel and SPCC (cold-rolled steel). The weir portion 33 is formed, for example, by bending the outer end of the cylindrical portion 32.

[0047] The hub seal 1 has the above-described configuration, and in the path from the opening S2a of the discharge gap S2 to the space 100a of the hub bearing 100, a labyrinth gap S1 that acts as a resistance against the intrusion of liquid foreign matter is provided upstream of the side lip 21. This allows the hub seal 1 to prevent liquid foreign matter from reaching the contact area between the side lip 21 and the flange portion 31 of the slinger 4. Additionally, a discharge gap S2 that acts as a discharge gap for liquid foreign matter is provided upstream of the labyrinth gap S1. This also allows the hub seal 1 to prevent liquid foreign matter from reaching the contact area between the side lip 21 and the flange portion 31 of the slinger 4. Furthermore, when the gap S3 forms a labyrinth seal, this gap S3 also allows the hub seal 1 to prevent liquid foreign matter from reaching the contact area between the side lip 21 and the flange portion 31 of the slinger 4.

[0048] As described above, the hub seal 1 prevents liquid foreign matter from reaching the contact area between the side lip 21 and the flange portion 31 of the slinger 4, thereby preventing the side lip 21 from being exposed to liquid foreign matter. As a result, liquid foreign matter is prevented from reaching the contact area between the intermediate lip 22 and the flange portion 31 of the slinger 4, preventing the intermediate lip 22 from being exposed to liquid foreign matter. This improves the sealing performance of the side lip 21 and the intermediate lip 22 against liquid foreign matter.

[0049] In this way, the hub seal 1 according to this embodiment can improve sealing performance against liquid foreign matter.

[0050] Furthermore, the labyrinth gap S1, discharge gap S2, and gap S3 prevent the intrusion of liquid foreign matter without bringing the seal body 3 and the slinger 4 into contact, improving the sealing performance of the hub seal 1 against liquid foreign matter. In other words, the hub seal 1 can improve its sealing performance against liquid foreign matter without increasing torque resistance.

[0051] Furthermore, as described above, the labyrinth gap S1, the discharge gap S2, and the gap S3 prevent liquid foreign matter from reaching the contact points between the side lip 21 and the intermediate lip 22 and the flange portion 31 of the slinger 4. For this reason, the required sealing performance may be maintained even if the interference between the side lip 21 and the flange portion 31 is reduced, and the required sealing performance may be maintained even if the interference between the intermediate lip 22 and the flange portion 31 is reduced. In this way, the hub seal 1 may be able to reduce torque resistance while maintaining the required sealing performance.

[0052] Furthermore, as described above, the hub seal 1 has the ring protrusion 25, which makes it difficult for foreign matter to enter the discharge gap S2.

[0053] Next, a hub seal 2 according to a second embodiment of the present invention will be described. Figure 6 is a partially enlarged cross-sectional view of the vicinity of the hub seal 2 in Figure 1, and Figure 7 is a partially enlarged cross-sectional view of the hub seal 2 in Figure 6. Figure 6 shows one side of the cross section of the hub seal 2 relative to the axis x. The hub seal 2 differs from the above-described hub seal 1 mainly in the shape of the slinger. Below, with regard to the configuration of the hub seal 2, components that are the same as or have similar functions to the above-described hub seal 1 will be assigned the same reference numerals and their description will be omitted, and only different components will be described.

[0054] The hub seal 2 is an outer hub seal, and as shown in FIGS. 1 and 6 , it is mounted between the outer opening 101b of the outer ring 101 of the hub bearing 100 and the hub ring 105. Therefore, the components of the hub seal 2 mounted on the hub bearing 100 are opposite in orientation in the direction of the axis x, with the inside facing outward and the outside facing inward, compared to the corresponding components of the hub seal 1 mounted on the hub bearing 100. As shown in FIG. 6 , the hub seal 2 has a seal body 3 and a slinger 6. The slinger 6 differs from the slinger 4 of the hub seal 1 mainly in that it has a flange portion 35 that has a different shape from the flange portion 31 of the slinger 4 of the hub seal 1. The seal body 3 of the hub seal 2 differs in specific dimensions and shape from the seal body 3 of the hub seal 1 to correspond to the structure of the portion of the hub bearing 100 to which it is mounted. Similarly, the slinger 6 of the hub seal 2 has different specific dimensions and shape from the slinger 4 of the hub seal 1 in accordance with the structure of the portion of the hub bearing 100 to which it is attached.

[0055] As shown in Figures 6 and 7, the reinforcing ring 10 of the hub seal 2 is formed to be press-fitted into the through hole 107 of the outer ring 101 of the hub bearing 100 and fitted thereto, and for example, the fitting portion 11 is formed to be press-fitted into the outer opening 101b of the outer ring 101 and fitted to its inner surface 101f.

[0056] As shown in Figure 6, the side lips 21 and intermediate lip 22 of the hub seal 2 each extend outward from the base portion 24. When the hub seal 2 is in use and attached to the hub bearing 100 with the seal body 3 and slinger 6 in a specified relative position, the side lips 21 and intermediate lip 22 are each formed so that their tips come into contact with the flange portion 35 of the slinger 6 with a specified interference. The grease lip 23 extends inward and toward the inner periphery from the base portion 24. When the hub seal 2 is in use, the tip of the grease lip 23 comes into contact with the fitting portion 34 of the slinger 6 from the outer periphery with a specified interference.

[0057] As shown in Fig. 6, the annular projection 25 protrudes outward, for example, protruding obliquely outward and toward the outer periphery from the outer peripheral end of the base portion 24. When the hub seal 2 is in use, the annular projection 25 is formed so that its tip faces the side surface 105f of the wheel mounting flange 105b with a gap between them, as shown in Fig. 6. When the hub seal 2 is in use, the gasket portion 26 of the hub seal 2 is formed so that it contacts the outer peripheral surface 101g of the outer opening 101 of the outer ring 101. When the hub seal 2 is in use, the gasket portion 27 of the hub seal 2 is formed so that it contacts the outer end surface 101h of the outer opening 101b of the outer ring 101.

[0058] The slinger 6 is a metal plate-like member having an annular or approximately annular shape with the axis x as its central axis or approximately as its central axis, and is formed so as to be press-fitted into the hub wheel 105 of the inner ring 102 of the hub bearing 100 and fitted to the hub wheel 105, as shown in Fig. 6. The fitting portion 34 of the slinger 6 is formed so as to be fitted to the outer peripheral surface 105e of the shaft portion 105a of the hub wheel 105, for example, as shown in Fig. 6.

[0059] As shown in Fig. 6, the flange portion 35 of the slinger 6 has a shape corresponding to the side surface 105f near the base of the wheel mounting flange 105b of the hub wheel 105. For example, as shown in Fig. 6, the cross-sectional shape of the flange portion 35 taken along a plane including the axis x is a shape that is smoothly curved and convex toward the inner periphery. Furthermore, the cross-sectional shape of the contact surface 35a, which is the surface of the flange portion 35 facing the inner and outer periphery, taken along a plane including the axis x is a curved shape that is smoothly curved and convex toward the outer and inner periphery, and the contact surface 35a of the flange portion 35 smoothly connects to the contact surface 34a of the fitting portion 34.

[0060] As shown in Figures 6 and 7 , the cylindrical portion 32 of the slinger 6 extends inward from, for example, the outer peripheral end of the flange portion 35. The cylindrical portion 32 has a weir portion 33. In the hub seal 2, as shown in Figures 6 and 7 , the end 33 a of the weir portion 33 faces the outer cylindrical surface 3 a of the seal body 3 from the inner peripheral side in the radial direction, and an annular labyrinth gap S1 is formed between the end 33 a of the weir portion 33 and the outer cylindrical surface 3 a. Also, as shown in Figures 6 and 7 , the inner cylindrical surface 32 a of the cylindrical portion 32 faces the outer cylindrical surface 3 a from the inner peripheral side in the radial direction, and a discharge gap S2 is formed between the inner cylindrical surface 32 a of the cylindrical portion 32 and the outer cylindrical surface 3 a. In the hub seal 2, as shown in Figure 6 , the outer cylindrical surface 3 a faces the end 33 a of the weir portion 33 and a part of the inner cylindrical surface 32 a of the cylindrical portion 32 in the radial direction. The outer cylindrical surface 3 a may be opposed to the end 33 a of the dam portion 33 and the entire inner cylindrical surface 32 a of the cylindrical portion 32 in the radial direction.

[0061] As shown in Figures 6 and 7, the side surface 33c of the weir portion 33 of the hub seal 2 faces inward, and the side surface 33c faces the opposing portion 24b of the base portion 24 from the outside in the direction of the axis x, and an annular gap S3 is formed between the side surface 33c of the weir portion 33 and the opposing portion 24b of the base portion 24.

[0062] As shown in FIG. 7 , in the hub seal 2, the labyrinth gap S1 has a radial width W1 and a length L1 in the axial x direction, respectively, so that the labyrinth gap S1 provides resistance to liquid foreign matter. The discharge gap S2 has a radial width W2 and a length L2 in the axial x direction, respectively, so that the discharge gap S2 does not form a labyrinth seal against liquid foreign matter, but instead discharges liquid foreign matter that flows into the discharge gap S2 and is bounced off the weir surface 33b and the labyrinth gap S1 from the opening S2a to the outside of the discharge gap S2. The gap S3 has a radial width W3 and a length L3 in the axial x direction, so that the gap S3 provides a labyrinth seal against liquid foreign matter. The gap S3 may also be a gap that does not form a labyrinth seal against liquid foreign matter.

[0063] As described above, the hub seal 2 has the same configuration as the hub seal 1 and functions in the same manner as the hub seal 1.

[0064] In this way, the hub seal 2 according to this embodiment can improve sealing performance against liquid foreign matter.

[0065] As with the hub seal 1, the inner cylindrical surface 32a of the cylindrical portion 32 of the slinger 6 may extend at an inclination relative to the axis x in cross section, as shown in Fig. 8 . Specifically, for example, as shown in Fig. 8 , the cylindrical portion 32 of the slinger 6 may be frustoconical. That is, as shown in Fig. 8 , the cylindrical portion 32 of the slinger 6 may be a conical or approximately conical cylindrical portion whose diameter increases inward in the axis x in cross section, and the inner cylindrical surface 32a may be a conical or approximately conical surface whose central axis is the axis x and whose diameter increases inward in the axis x. In this way, if the cylindrical portion 32 of the slinger 6 is frustoconical and the inner cylindrical surface 32a of the cylindrical portion 32 is a conical surface that inclines outward from the flange portion 31 inward, the discharge action of the discharge gap S2 can be strengthened.

[0066] 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.

[0067] 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.

[0068] For example, the outer cylindrical surface 3a may be formed by the fitting portion 11 of the reinforcing ring 10. In this case, the base portion 24 of the elastic body portion 20 does not have the outer peripheral opposing portion 24a. Also, for example, the elastic body portion 20 of the hub seals 1 and 2 may not have the ring protrusion portion 25, the gasket portion 26, or the gasket portion 27. Also, for example, if the elastic body portion 20 does not have the ring protrusion portion 25, the gasket portion 26, or the gasket portion 27, the reinforcing ring 10 of the hub seals 1 and 2 may not have the flange portion 13.

[0069] 1, 2 Hub seal (sealing device) 3 Seal body (sealing device body) 3a Outer cylinder surface 4, 6 Slinger 5 Gasket 10 Reinforcement ring 11 Fitting portion 11a Outer circumference surface 12 Lip support portion 12a Return portion 12b Lip flange portion 13 Flange portion 20 Elastic body portion 21 Side lip 22 Intermediate lip 23 Grease lip 24 Base portion 24a Outer circumference opposing portion 24b Opposing portion 25 Ring protrusion portion 25a Inner end 26, 27 Gasket portion 31, 35 Flange portion (annular portion) 31a, 35a Contact surface 31b Inner circumference surface 32 Cylinder portion 32a Inner cylinder circumference surface 33 Dam portion 33a End 33b Dam surface 33c Side surface 34 Fitting portion 34a Contact surface, 100 hub bearing, 100a clearance, 101 outer ring, 101a inner opening, 101b outer opening, 101c inner peripheral surface, 101d outer peripheral surface, 101e inner end surface, 101f inner peripheral surface, 101g outer peripheral surface, 101h outer end surface, 102 inner ring, 103 bearing ball, 104 inner ring member, 104a outer peripheral surface, 105 hub ring, 105a shaft portion, 105b wheel mounting flange, 105c transition portion, 105d inner peripheral surface, 105e outer peripheral surface, 105f side surface, 106 retainer, 107 through hole, G grease, L1, L2, L3 length, S1 labyrinth clearance (first clearance), S2 discharge clearance (second clearance), S2a opening, S3 clearance, x Axis line, W1, W2, W3 width

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 sealing device comprising: a sealing device main body fixed to the outer peripheral member, the sealing device main body comprising a reinforcing ring annular about the axis, and an elastic body portion attached to the reinforcing ring and formed from an elastic body annular about the axis, the slinger comprising an annular ring portion which is a portion extending along a radial direction and annular about the axis, and a cylindrical portion which is a cylindrical portion extending from an outer peripheral end of the annular portion toward one side in the axial direction along the axis, the sealing device main body being formed with an outer cylindrical surface which is a cylindrical surface annular about the axis and extending along the axis, the elastic body portion having a side lip extending toward the other side in the axial direction on the inner peripheral side of the outer cylindrical surface and adapted to come into contact with the slinger, A sealing device, wherein the cylindrical portion of the slinger is positioned more outer circumferentially than the side lip, the cylindrical portion of the slinger has a dam portion which is an annular portion extending toward the outer circumferential side at the end of the one side, the outer cylindrical surface of the sealing device main body faces at least a portion including the end of the dam portion of the cylindrical portion of the slinger from the outer circumferential side, and a first gap narrower than the radial width of a second gap between the outer cylindrical surface and a portion of the cylindrical portion that is not the end of the dam portion facing the outer cylindrical surface is formed between the outer cylindrical surface and the end of the dam portion.

2. A sealing device as described in claim 1, wherein the radial width of the first gap is such that a labyrinth seal is formed against liquid foreign matter, and the radial width of the second gap is such that a labyrinth seal is not formed against liquid foreign matter.

3. The sealing device according to claim 1, wherein foreign matter that flows into the second gap can be discharged from the second gap.

4. A sealing device as described in claim 3, wherein the dam portion has a dam surface which extends inward from the end and is a surface facing the other side which is annular about the axis, and the tubular portion has an inner tubular surface which extends from the inner circumferential end of the dam surface to the other side and is a cylindrical surface facing the outer circumferential side.

5. A sealing device as set forth in claim 4, wherein the inner cylindrical surface of the cylindrical portion increases in diameter toward the one side in the axial direction.

6. The sealing device according to claim 1, wherein the end of the dam portion is a surface facing the outer periphery of an annular shape around the axis.

7. The sealing device according to claim 1, wherein the elastic body portion forms the outer cylindrical surface.

8. The sealing device according to claim 1, wherein the elastic body portion has an intermediate lip extending toward the slinger on the inner peripheral side of the side lip.

9. The sealing device according to claim 8, wherein the elastic body portion has a grease lip extending from the one side beyond the intermediate lip and contacting the slinger.

10. The sealing device of claim 1, wherein the one side is an inner side and the sealing device is an outer side.

11. The sealing device of claim 1, wherein the one side is an outer side and the sealing device is an inner side.

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