sealing device

Abstract

To improve sealing performance against foreign matter while suppressing an increase in torque resistance. [Solution] The hub seal 1 comprises a seal body 3 fixed to the outer ring 101 and a slinger 4 fixed to the inner ring 102. The seal body 3 comprises an annular reinforcing ring 10 and an annular elastic body portion 20 attached to the reinforcing ring 10. The elastic body portion 20 has an annular side lip 21 that extends outward and contacts the slinger 4. The side lip 21 has an annular tip portion 25 that contacts the slinger 4 and an annular projection portion 30 provided on the outer circumference side of the tip portion 25. The projection portion 30 covers the tip portion 25 from the outer circumference side in the radial direction.

Description

Technical Field

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

Background Art

[0002] In a vehicle, for example, an automobile, a hub seal, which is a sealing device, has conventionally been attached to a hub bearing that rotatably supports a wheel in order to seal a gap formed between an outer ring and an inner ring. The hub seal aims to seal a lubricant inside the hub bearing and prevent foreign matter from entering the internal space. Since the hub bearing is in a harsh environment directly exposed to foreign matter such as rainwater, muddy water, and dust, the hub seal is required to improve its sealing performance against foreign matter. For this reason, some conventional hub bearings have a plurality of contacting seal lips.

[0003] On the other hand, due to requirements such as fuel efficiency improvement, the hub seal is required to reduce the sliding resistance (torque resistance) applied to the hub bearing by the seal lip. In order to improve the sealing performance of the hub seal, it is conceivable to further increase the number of seal lips, but this will increase the torque resistance of the hub seal. For this reason, a hub seal has been proposed that forms a labyrinth seal and improves the sealing performance against foreign matter without increasing the torque resistance of the hub seal by increasing the number of seal lips (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As mentioned above, hub bearings are used in harsh environments where they are directly exposed to foreign matter such as rainwater, mud, and dust. Therefore, even with hub seals that have labyrinth seals as described above, liquid foreign matter, especially rainwater, mud, and dust, can sometimes penetrate beyond the labyrinth seal. If the seal lip becomes caught in the foreign matter that has entered, the sealing performance may deteriorate due to wear of the seal lip. Thus, for sealing devices such as hub seals, there is a need for a configuration that can reduce torque resistance while improving sealing performance against foreign matter.

[0006] The present invention has been made in view of the above-mentioned problems, and its objective is to provide a sealing device that can improve sealing performance against foreign matter while suppressing an increase in torque resistance. [Means for solving the problem]

[0007] To achieve the above objective, the sealing device according to the present invention is a sealing device for sealing a gap between an outer peripheral member that is rotatable relative to each other about an axis and an inner peripheral member that is at least partially surrounded by the outer peripheral member, comprising a sealing device body fixed to the outer peripheral member, the sealing device body comprising an annular reinforcing ring about the axis and an elastic body portion attached to the reinforcing ring and formed from an annular elastic material about the axis, the elastic body portion having an annular side lip that extends toward one side in the axial direction and contacts a contact target portion which is a portion provided on the inner peripheral member, the side lip having a tip portion which is an annular end that contacts the contact target portion and a projection portion which is an annular portion provided on the outer peripheral side of the tip portion, the projection portion covering the tip portion from the outer peripheral side in the radial direction.

[0008] In a sealing device according to one aspect of the present invention, the projection protrudes in the axial direction from one side of the tip portion.

[0009] In a sealing device according to one aspect of the present invention, the thickness of the projection is thinner than the thickness of the side lip at the tip.

[0010] In a sealing device according to one aspect of the present invention, the projection is configured such that when its tip comes into contact with the contact target, it does not come into contact with the contact target.

[0011] In a sealing device according to one aspect of the present invention, the contact target portion has an annular surface that the tip portion contacts, and the angle between the extension direction of the projection portion and the extension direction of the tip portion of the seal lip is set based on the angle between the extension direction of the tip portion of the seal lip that contacts the surface of the contact target portion and the surface of the contact target portion.

[0012] In a sealing device according to one aspect of the present invention, the contact target portion has an annular surface that the tip portion contacts, and the length of the projection in the protruding direction is set based on the angle of the extension direction of the tip portion of the seal lip that contacts the surface of the contact target portion with respect to the surface of the contact target portion.

[0013] In a sealing device according to one aspect of the present invention, the projection is configured to contact the contact target.

[0014] A sealing device according to one aspect of the present invention further comprises an annular intermediate lip extending toward one side on the inner circumference side of the side lip, and in contact with the contact target portion.

[0015] A sealing device according to one aspect of the present invention further comprises a slinger, the slinger being fixed to the inner circumferential member and being a contact target.

[0016] In the sealing device according to one aspect of the present invention, the slinger has a fitting portion which is a cylindrical portion extending along the axis, and an annular portion which is an annular portion extending radially from an end portion on one side of the fitting portion, and the side lip is adapted to contact the annular portion of the slinger.

[0017] The sealing device according to one aspect of the present invention is a hub seal used for a hub bearing.

Advantages of the Invention

[0018] According to the sealing device of the present invention, it is possible to improve the sealing performance against foreign matter while suppressing an increase in torque resistance.

Brief Description of the Drawings

[0019] [Figure 1] It is a cross-sectional view showing a cross-section by a plane including the axis of a hub bearing as an example. [Figure 2] It is a partially enlarged cross-sectional view of the vicinity of the hub seal as the sealing device according to the embodiment of the present invention in FIG. 1. [Figure 3] It is a cross-sectional view showing a cross-section by a plane including the axis of the seal body in the hub seal. [Figure 4] It is a partially enlarged cross-sectional view showing an enlarged side lip in the seal body shown in FIG. 3. [Figure 5] It is a partially enlarged cross-sectional view showing a modified example of the protrusion in the side lip. [Figure 6] It is a partially enlarged cross-sectional view showing a modified example of the protrusion in the side lip. [Figure 7] It is a partially enlarged cross-sectional view showing an enlarged vicinity of the protrusion of the hub seal in the use state. <​​​​​​Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, not all of the plurality of components are labeled, and some labels of the plurality of components may be omitted.

[0021] The 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 that are relatively rotatable with respect to each other about an axis. The inner peripheral side member is at least partially surrounded by the outer peripheral side 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 by a plane including the axis of a hub bearing 100 as an example. As shown in FIG. 1, the hub bearing 100 is a conventionally known hub bearing, is provided in a vehicle such as an automobile, and rotatably supports a wheel in an axle or a suspension device. Note that the sealing device according to the present invention is not limited to a hub seal, and the application target of the sealing device according to the present invention is not limited to the hub bearing of a vehicle. For example, the sealing device according to the present invention can also be applied to other devices and mechanisms such as in-wheel motors. Further, the application target of the sealing device according to the present invention is not limited to a hub bearing.

[0022] Specifically, as shown in Figure 1, the hub bearing 100 comprises an annular outer ring 101 as an outer peripheral member with axis x as its central axis or substantially central axis, an inner ring 102 as an inner peripheral member that is rotatable relative to the outer ring 101 and partially surrounded by the outer ring 101 with axis x as its central axis or substantially central axis, and a plurality of bearing balls (rolling elements) 103 disposed between the outer ring 101 and the inner ring 102. In the operating state of the hub bearing 100 attached to a vehicle or the like, the outer ring 101 is fixed, and the inner ring 102 becomes rotatable relative to the outer ring 101. Specifically, the inner ring 102 has an inner ring member 104 and a hub ring 105, and the hub ring 105 has a cylindrical or substantially cylindrical shaft portion 105a extending along axis x and a wheel mounting flange 105b. The wheel mounting flange 105b is a disc-shaped portion that extends outward from one end of the shaft portion 105a towards the outer circumference, and is the portion to which a brake disc rotor and tire wheel (not shown) are attached by multiple hub bolts (not shown). The shaft portion 105a and the wheel mounting flange 105b are smoothly connected on the inner circumference side. An annular root surface 105c extends from the root portion of the wheel mounting flange 105b. The root surface 105c is an inward-facing surface, and is, for example, an annular or substantially annular surface with axis x as the central axis or substantially the central axis. The root surface 105c also has, for example, an inner circumference portion and an outer circumference portion that extends outward from this inner circumference portion. The inner circumference portion of the root surface 105c is, for example, an annular surface that is recessed outward, as shown in Figure 1, and the outer circumference portion of the root surface 105c is, for example, an annular surface along a plane perpendicular to axis x, as shown in Figure 1. The inner ring member 104 is fitted to the inner end of the shaft portion 105a of the hub ring 105 in order to hold the bearing balls 103 in the internal space S, which is the gap between the outer ring 101 and the inner ring 102. Within the internal space S between the outer ring 101 and the inner ring 102, the bearing balls 103 are held by the cage 106.

[0023] The outer ring 101 has a through hole 107 extending in the axial direction x, into which the shaft portion 105a of the hub ring 105 of the inner ring 102 is inserted, forming an annular internal space S extending along the axial direction x between the shaft portion 105a and the through hole 107. In this internal space S, as described above, bearing balls 103 are housed and held by a cage 106, and lubricant is applied or injected. A sealing device 1 is attached to the inner opening 101a of the outer ring 101, which forms an opening that opens the internal space S between the inner ring member 104 and the shaft portion 105a and the through hole 107 inward. On the other hand, a sealing device 2 is attached to the outer opening 101b of the outer ring 101, which forms an opening that opens the internal space S outward.

[0024] Sealing device 1 is a sealing device according to an embodiment of the present invention and is an inner hub seal. On the other hand, sealing device 2 is a conventionally known hub seal and is an outer hub seal. Sealing devices 1 and 2 seal the internal space S between the shaft portion 105a of the hub ring 105 and the inner ring member 104 and the outer ring 101, preventing lubricant in the internal space S from leaking out to the outside, and also preventing foreign matter such as rainwater, mud, and dust from entering the internal space S from the outside. Note that sealing device 2 may be a sealing device according to the present invention. In this case, sealing device 2 has the same configuration as sealing device 1, but its specific form, such as shape and size, corresponds to the part of the hub bearing 100 to which sealing device 2 is attached. Furthermore, the configuration of the hub bearing to which 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 called a hub seal.

[0025] Next, a hub seal (sealing device) 1 according to an embodiment of the present invention will be described. In the hub seal 1 according to an embodiment of the present invention, as an example, the contact target portion, which is a part provided on the inner ring 102 as an inner circumference side member, is a slinger 4, as will be described later. Figure 2 is a partially enlarged cross-sectional view of the vicinity of the hub seal 1 in Figure 1. Figure 2 shows one side of the cross-section of the hub seal 1 with respect to the axis x, in a plane containing the axis x, in a working state attached to the hub bearing 100. In the working state of the hub seal 1, the seal body 3, which is the sealing device body described later, and the slinger 4 are attached to the hub bearing 100 so as to be in a predetermined relative position.

[0026] As shown in Figure 2, the hub seal 1 comprises a seal body 3, which is the main body of a sealing device fixed to the outer ring 101, and a slinger 4, which is fixed to the inner ring 102. The seal body 3 comprises an annular reinforcing ring 10 about the axis x, and an elastic body portion 20 attached to the reinforcing ring 10 and formed from an annular elastic material about the axis x. The elastic body portion 20 has an annular side lip 21 that extends toward one side (inward) in the axial x direction and contacts the slinger 4. The side lip 21 has a tip portion 25, which is the annular end that contacts the slinger 4, and a projection portion 30, which is an annular portion provided on the outer circumference side of the tip portion 25. The projection portion 30 covers the tip portion 25 from the outer circumference side in the radial direction. The configuration of the hub seal 1 will be described in detail below.

[0027] The radial direction is the direction perpendicular to the axis x. The outer circumference is the side away from the axis x in the radial direction, as shown in Figures 1 and 2, in the direction of arrow c. The inner circumference is the side approaching the axis x in the radial direction, as shown in Figures 1 and 2, in the direction of arrow d. The inner side is one side in the direction of the axis x, as shown in Figures 1 and 2, in the direction of arrow a. The outer side is the other side in the direction of the axis x, as shown in Figures 1 and 2, in the direction of arrow b. In a hub bearing 100 mounted on a vehicle, the inner side is the body side, and the outer side is the wheel side. The axis x of the hub seal 1 mounted on the hub bearing 100 coincides with or approximately coincides with the axis of the hub bearing 100. For the sake of explanation, the axis of the hub bearing 100 will be referred to as axis x.

[0028] The slinger 4 is fixed to the inner ring member 104 of the inner ring 104 and forms a contact area on the inner ring 104. The contact area is the part that the side lip 21 contacts. As shown in Figures 1 and 2, for example, the slinger 4 has a fitting portion 41 which is a cylindrical portion extending along the axis x, and a flange portion 42 which is an annular portion extending radially from the inner end of the fitting portion 41. As described above, the side lip 21 is in contact with the slinger 4, specifically in contact with the flange portion 42. The slinger 4 is a metal plate-shaped member that is annular or substantially annular in shape with the axis x as its central axis or substantially its central axis, and as shown in Figures 1 and 2, it is formed to be press-fitted into the inner ring member 104 of the inner ring 102 of the hub bearing 100 and fitted onto the inner ring member 104.

[0029] The fitting portion 41 is a cylindrical or substantially cylindrical portion with axis x as its central axis or substantially central axis, as shown for example in Figure 2, and is formed to fit onto the outer circumferential surface 104a of the inner ring member 104. The contact surface 41a, which faces the outer circumferential side of the fitting portion 41, is a cylindrical or substantially cylindrical surface with axis x as its central axis or substantially central axis, as shown for example in Figure 2. The flange portion 42 is a disc-shaped or substantially disc-shaped portion that extends radially with axis x as its central axis or substantially central axis, and forms an annular portion that protrudes radially from the outer circumferential surface 104a of the inner ring member 104, as shown in Figure 2. The contact surface 42a, which faces the outside of the flange portion 42, is a surface that extends on a plane parallel or substantially parallel to a plane perpendicular to axis x, for example.

[0030] Furthermore, the slinger 4 is designed to be in close contact with the inner ring member 104. Specifically, the fitting portion 41 of the slinger 4 and the inner ring member 104 are designed to be in close contact with each other so that no gap is formed between the fitting portion 41 and the inner ring member 104 through which foreign matter can pass. However, the slinger 4 and the inner ring member 104 do not necessarily have to be in close 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 internal space S between the outer ring 101 and the inner ring 102 through the gap between the slinger 4 and the inner ring member 104.

[0031] The slinger 4 is formed integrally from a metal plate of uniform thickness, for example, by pressing or forging, and the fitting portion 41 and flange portion 42 are integrally formed parts of the slinger 4. Examples of metal materials for the slinger 4 include stainless steel and SPCC (cold-rolled steel).

[0032] Figure 3 is a cross-sectional view showing a cross-section of the seal body 3 along a plane containing the axis x. Note that only one side of the cross-section of the seal body 3 with respect to the axis x is shown in Figure 3. Also, Figure 3 shows the seal body 3 in its natural state when no external force is applied to it. The reinforcing ring 10 of the seal body 3 is an annular, plate-shaped metal member with axis x as its central axis or approximately its central axis, as shown in Figures 2 and 3, and is formed to be press-fitted into the through hole 107 of the outer ring 101 of the hub bearing 100, as shown in Figure 2. By press-fitting the reinforcing ring 10 into the outer ring 101, the seal body 3 is fixed to the outer ring 101. The reinforcing ring 10 has, for example, a cylindrical portion 11 and a lip support portion 12 that curves inward from the outer end of the cylindrical portion 11 and extends to the inner circumference, as shown in Figures 2 and 3.

[0033] As shown in Figures 2 and 3, the cylindrical portion 11 has, for example, an outer fitting portion 11a and an inner gasket support portion 11b. The fitting portion 11a is, for example, a cylindrical or substantially cylindrical portion with axis x as its central axis or substantially its central axis. The cylindrical portion 11 is formed such that, as shown in Figures 1 and 2, the outer peripheral surface 11c, which is the outer peripheral surface of the fitting portion 11a, is press-fitted into the inner opening 101a of the outer ring 101 and fitted to its inner peripheral surface 101c. The gasket support portion 11b extends from the inner end of the fitting portion 11a, and the outer peripheral surface 11d, which is the outer peripheral surface of the gasket support portion 11b, is located on the inner peripheral side of the outer peripheral surface 11c of the fitting portion 11a.

[0034] The lip support portion 12 is shaped such that, for example, the side lip 21, and the intermediate lip 22 and grease lip 23 (described later) are positioned in the hub seal 1 relative to the slinger 4. The lip support portion 12 has a return portion 12a and a lip flange portion 12b, as shown in Figures 2 and 3. The return portion 12a is, for example, an annular plate-shaped portion that extends radially from the outer end of the cylindrical portion 11 and then curves inward, inclined with respect to the radial direction. 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. The reinforcing ring 10 is formed as a single member from a metal plate by pressing or forging, for example, and the cylindrical portion 11 and the lip support portion 12 are parts of the reinforcing ring 10 formed integrally from the same material and are integrally continuous. Examples of metal materials for the reinforcing ring 10 include stainless steel and SPCC (cold-rolled steel).

[0035] The elastic body portion 20 is attached to the reinforcing ring 10 as described above, and is integral with the reinforcing ring 10 so as to cover the reinforcing ring 10 from the inside, as shown in Figures 2 and 3. In addition to the side lip 21, the elastic body portion 20 has, for example, an intermediate lip 22 and a grease lip 23. The side lip 21, intermediate lip 22, and grease lip 23 are each annular sealing lips around the axis x. The grease lip 23 extends toward the axis x (inner circumference side), as shown in Figures 2 and 3, and is designed not to come into contact with the fitting portion 41 of the slinger 4, which will be described later. The side lip 21 and intermediate lip 22 come into contact with the flange portion 42 of the slinger 4, which will be described later, to prevent foreign matter from entering the internal space S of the hub bearing 100, and also to prevent lubricant from flowing out of the internal space S. The grease lip 23 also prevents lubricant from flowing out of the internal space S of the hub bearing 100. The grease slip 23 may also be in contact with the fitting portion 41 of the slinger 4.

[0036] Furthermore, the elastic body portion 20 has, for example, a base portion 24. As shown in Figures 2 and 3, the intermediate lip 22 and the grease lip 23 extend from the inner circumferential end of the base portion 24, respectively. The side lip 21 extends from the base portion 24, radially spaced apart from the intermediate lip 22, on the outer circumferential side of the intermediate lip 22, as shown in Figures 2 and 3. The base portion 24 is the part of the elastic body portion 20 that extends mainly to the inner surface of the reinforcing ring 10, spanning the cylindrical portion 11 and the lip support portion 12 of the reinforcing ring 10. Also, as shown in Figures 2 and 3, for example, the base portion 24 extends to the outer circumferential surface 11d of the gasket support portion 11b of the reinforcing ring 10, forming a gasket portion 24a on the outer circumferential surface 11d of the gasket support portion 11b. As shown in Figure 3, the gasket portion 24a protrudes outward from the outer peripheral surface 11c of the fitting portion 11a, and as shown in Figure 2, it is compressed radially between the gasket support portion 11b of the reinforcing ring 10 fitted to the inner opening 101a of the outer ring 101 and the inner peripheral surface 101c of the inner opening 101a. This ensures a seal between the inner opening 101a of the outer ring 101 and the seal body 3.

[0037] As shown in Figures 2 and 3, the side lip 21 specifically extends inward from the base portion 24 in an annular shape with axis x as the central axis or approximately the central axis. Also, as shown in Figure 2, in the operating state of the hub seal 1, which is attached to the hub bearing 100 so that the seal body 3 and the slinger 4 are in a predetermined relative position, the side lip 21 is formed so that its tip portion 25 contacts the flange portion 42 of the slinger 4 with a predetermined overlap. Specifically, the inner circumferential surface 21a of the tip portion 25 of the side lip 21 contacts the contact surface 42a of the flange portion 42 of the slinger 4. As a result, an annular contact surface 5 with a radial width is formed between the tip portion 25 of the side lip 21 and the contact surface 42a of the flange portion 42 of the slinger 4, as shown in Figure 2. Note that the inner circumferential surface 21a of the side lip 21 is an annular surface facing the inner circumference of the side lip 21. As shown in Figure 3, the side lip 21 has a shape that is, for example, a conical or substantially conical shape that widens inward in the axial x direction.

[0038] Figure 4 is a partially enlarged cross-sectional view showing an enlarged view of the side lip 21 shown in Figure 3. As shown in Figures 3 and 4, the side lip 21 has a main body portion 26, and a projection 30 is provided at the tip of the main body portion 26. The main body portion 26 and the projection 30 are part of the side lip 21 and are integrally connected to each other. The main body portion 26 is the part that extends from the base to the tip portion 25 of the side lip 21 and is the part that mainly exerts the sealing function of the side lip 21. The base of the side lip 21 is the part where the side lip 21 is connected to the base portion 24. The inner circumferential surface, which is the surface facing the inner circumference of the main body portion 26, is the inner circumferential surface 21a of the side lip 21. The main body portion 26 also has an outer circumferential surface 26a, which is the surface facing away from the inner circumferential surface 21a. The outer circumferential surface 26a of the main body portion 26 is an annular surface facing the outer circumference of the main body portion 26. The inner circumferential surface 21a is, for example, a frustoconical or substantially frustoconical surface that widens in diameter as it approaches the inside in the x-axis direction. Similarly, the outer circumferential surface 26a is, for example, a frustoconical or substantially frustoconical surface that widens in diameter as it approaches the inside in the x-axis direction.

[0039] As shown in Figures 3 and 4, a tip surface 26c extends outward from the tip 26b of the inner circumferential surface 21a of the main body portion 26. The tip 26b is the inner end of the inner circumferential surface 21a. The tip surface 26c is an annular surface that intersects with the inner circumferential surface 21a, and for example, at tip 26b it is perpendicular or nearly perpendicular to the inner circumferential surface 21a. Note that the tip surface 26c is not limited to being perpendicular to the inner circumferential surface 21a at tip 26b. Furthermore, the tip surface 26c extends toward the tip 26d of the outer circumferential surface 26a, for example. The tip 26d is the inner end of the outer circumferential surface 26a. The tip portion 25 of the side lip 21 is the inner end of the main body portion 26, and is the tip surface 26c and the portion near the tip surface 26c.

[0040] As shown in Figures 3 and 4, the projection 30 is adjacent to the tip surface 26c on its outer circumference and protrudes inward from the tip surface 26c. In other words, a step is formed between the projection 30 and the inner circumferential surface 21a of the main body 26 toward the outer circumference. As shown in Figure 4, the projection 30 has a shape that is, for example, a conical or substantially conical shape that expands inward in the axial x direction. In other words, the inner circumferential surface 31 and the outer circumferential surface 32 of the projection 30 are frustoconical or substantially frustoconical surfaces that expand inward in the axial x direction. The inner circumferential surface 31 is an annular surface facing the inner circumference of the projection 30, and the outer circumferential surface 32 is an annular surface facing the outer circumference of the projection 30. Furthermore, an annular tip surface 33 extends between the tip 31a of the inner circumferential surface 31 and the tip 32a of the outer circumferential surface 32. Tip 31a is the inner end of the inner circumferential surface 31, and tip 32a is the inner end of the outer circumferential surface 32.

[0041] As shown in Figure 4, on the outer circumference, there is no step between the projection 30 and the main body 26, and the outer surface 32 of the projection 30 and the outer surface 26a of the main body 26 are flush or nearly flush. Alternatively, the outer surface 32 of the projection 30 and the outer surface 26a of the main body 26 are smoothly connected. However, on the outer circumference, there may be a step between the projection 30 and the main body 26, and the outer surface 32 of the projection 30 and the outer surface 26a of the main body 26 do not have to be flush. Alternatively, the outer surface 32 of the projection 30 and the outer surface 26a of the main body 26 do not have to be smoothly connected. Thus, there is a step between the projection 30 and the main body 26 at least on the inner circumference side, and the thickness of the projection 30 is thinner than the thickness of the side lip 21 at the tip 25. The thickness of the projection 30 is the width between the inner circumferential surface 31 and the outer circumferential surface 32, and the thickness of the side lip 21 is the thickness of the main body 26, which is the width between the inner circumferential surface 21a and the outer circumferential surface 26a.

[0042] As described above, the projection 30 covers the tip portion 25 from the outer circumference in the radial direction. For example, as shown in Figures 3 and 4, the projection 30 protrudes inward from the tip portion 25 in the axial x direction. Specifically, at least a portion of the tip surface 33 of the projection 30 is located inward from the tip 26b of the inner circumferential surface 21a of the main body portion 26 in the axial x direction. For example, the tip 31a of the inner circumferential surface 31 of the projection 30 is located inward from the tip 26b of the inner circumferential surface 21a of the main body portion 26 in the axial x direction. Also, for example, the tip 32a of the outer circumferential surface 32 of the projection 30 is located inward from the tip 26b of the inner circumferential surface 21a of the main body portion 26 in the axial x direction.

[0043] Furthermore, the projection 30 is designed so as not to come into contact with the contact surface 42a of the slinger 4 when the hub seal 1 is in use and the tip 25 of the side lip 21 is in contact with the contact surface 42a of the slinger 4. When the hub seal 1 is in use, the projection 30 does not come into contact with the contact surface 42a of the slinger 4, for example, the length L of the projection 30 in the projection direction is adjusted. The projection direction is the direction in which the projection 30 protrudes from the tip surface 26c of the main end 26, and the length L is, for example, the length in the axial x direction between the root end 31b, which is the root end of the inner circumferential surface 31, and the part of the tip surface 33 that protrudes the most inward in the axial x direction. Specifically, as shown in Figure 4, the length L is, for example, the length in the axial x direction between the root end 31b and the tip 31a of the inner circumferential surface 31. Furthermore, length L is specifically the length in the x-direction along the axis between the root end 31b of the inner circumferential surface 31 and the tip end 32a of the outer circumferential surface 32.

[0044] Furthermore, in the operating state of the hub seal 1, the inclination angle θ of the projection 30 is adjusted so that the projection 30 does not come into contact with the contact surface 42a of the slinger 4. The inclination angle θ is the angle between the projection direction of the projection 30 and the extension direction of the main body 26. The extension direction of the main body 26 is the direction in which the main body 26 extends from the base 24, for example, the extension direction of the inner circumferential surface 21a. Specifically, for example, as shown in Figure 4, the inclination angle θ is the angle between the line drawn by the inner circumferential surface 31 of the projection 30 and the line drawn by the inner circumferential surface 21a of the main body 26 in a cross section including axis x.

[0045] More specifically, in the operating state of the hub seal 1, the length L of the projection 30 is set so that the projection 30 does not come into contact with the contact surface 42a of the slinger 4 on the side lip 21 when the main body 26 is deformed due to contact with the contact surface 42a of the slinger 4. Alternatively, the inclination angle θ of the projection 30 is set so that the projection 30 does not come into contact with the contact surface 42a of the slinger 4 on the side lip 21 when the main body 26 is deformed due to contact with the contact surface 42a of the slinger 4 in the operating state of the hub seal 1. Alternatively, the length L and inclination angle θ of the projection 30 are set so that the projection 30 does not come into contact with the contact surface 42a of the slinger 4 on the side lip 21 when the main body 26 is deformed due to contact with the contact surface 42a of the slinger 4 in the operating state of the hub seal 1. In addition, when the hub seal 1 is in use, other morphological elements of the projection 30 may be adjusted so that the projection 30 does not come into contact with the contact surface 42a of the slinger 4 in the side lip 21, which is deformed by contact with the contact surface 42a of the slinger 4.

[0046] For example, in the operating state of the hub seal 1, the difference between the extension angle of the main body 26 at the side lip 21 when the main body 26 is deformed by contact with the contact surface 42a of the slinger 4 and the extension angle of the main body 26 at the side lip 21 when it is not deformed in the free state of the hub seal 1 (hereinafter also referred to as the displacement angle) can be obtained in advance, and the length L of the projection 30 and the inclination angle θ of the projection 30 can be set based on this displacement angle. The displacement angle can be obtained in advance by measurement or calculation, etc.

[0047] As shown in Figures 2 and 3, the intermediate lip 22 extends inward from the base portion 24a, similar to the side lip 21, on an inner circumference side than the side lip 21. When the hub seal 1 is in use, the intermediate lip 22 is formed so that its tip portion 22a contacts the flange portion 42 of the slinger 4 with a predetermined overlap. Specifically, the inner circumferential surface 22b of the tip portion 22a of the intermediate lip 22 contacts the flange portion 42 of the slinger 4. The inner circumferential surface 22b of the intermediate lip 22 is an annular surface facing the inner circumference of the intermediate lip 22. As shown in Figure 3, the intermediate lip 22 has a shape that is, for example, a conical or substantially conical shape that expands inward in the axial x direction.

[0048] The grease slip 23 extends annularly from the base portion 24 outward and inward, with axis x as the central axis or approximately the central axis, as shown in Figures 2 and 3. As shown in Figure 2, when the hub seal 1 is in use, the tip 23a of the grease slip 23 does not come into contact with the fitting portion 41 of the slinger 4, and an annular gap is formed between the tip 23a and the fitting portion 41 of the slinger 4. The radial width of the gap between the tip 23a and the fitting portion 41 is, for example, a desired size that can seal the lubricant in the internal space S of the hub bearing 100. Note that the hub seal 1 does not necessarily have a grease slip 23. Also, as described above, the tip 23a of the grease slip 23 may come into contact with the fitting portion 41 of the slinger 4.

[0049] The elastic body portion 20 is integrally attached to the reinforcing ring 10, and the aforementioned side lip 21, intermediate lip 22, grease lip 23, and base portion 24 are parts of the elastic body portion 20 formed integrally from the same material and are integrally continuous. The elastic body of the elastic body portion 20 can be, for example, various rubber materials. These various rubber materials are synthetic rubbers such as nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), and fluororubber (FKM).

[0050] The shape of the projection 30 is not limited to a straight-line shape in the cross-section described above. As described above, the shape of the projection 30 may be any other shape as long as the projection 30 does not come into contact with the contact surface 42a of the flange portion 42 of the slinger 4 in the hub seal 1 in use. For example, as shown in Figure 5, the projection 30 may be bent to protrude outward, or as shown in Figure 6, the projection 30 may be bent to protrude inward. In this case, the bend of the projection 30 may be curvature, flexion, or any other form of bending.

[0051] Furthermore, as shown in Figure 2, in the hub seal 1 in use, the outer peripheral end 42b of the flange portion 42 of the slinger 4 faces the seal body 3 from the inner peripheral side in the radial direction, and an annular gap S1 is formed between the outer peripheral end 42b of the flange portion 42 and the seal body 3. Specifically, for example, as shown in Figure 2, the outer peripheral end 42b of the flange portion 42 faces the base portion 24 of the elastic body portion 20 attached to the cylindrical portion 11 of the reinforcing ring 10 of the seal body 3. Note that if the elastic body portion 20 is not formed at the position of the cylindrical portion 11 of the reinforcing ring 10 that faces the outer peripheral end 42b of the flange portion 42 in the radial direction, an annular gap S1 is formed between the outer peripheral end 42b of the flange portion 42 and the cylindrical portion 11 of the reinforcing ring 10.

[0052] The gap S1 is designed to form a labyrinth seal against foreign matter. For example, the radial width and the width in the x-axis direction of the gap S1 are set so that the gap S1 forms a labyrinth seal. The labyrinth seal formed by the gap creates a resistive effect that prevents foreign matter from entering the gap, thus resisting the entry of foreign matter into the gap.

[0053] The hub seal 1 has the configuration described above. When the hub seal 1 is in use, the intermediate lip 22 is in contact with the contact surface 42a of the flange portion 42 of the slinger 4, and the tip portion 25 of the side lip 21 is in contact with the contact surface 42a of the flange portion 42, thereby sealing the internal space S of the hub bearing 100 from the outside. This prevents foreign matter from entering the internal space S of the hub bearing 100. In addition, the grease lip 23 prevents lubricant from flowing out of the internal space S. Furthermore, the annular gap S1 between the outer peripheral end 42b of the flange portion 42 of the slinger 4 and the base portion 24 of the elastic body portion 20 of the seal body 3 forms a labyrinth seal, thereby preventing foreign matter from approaching the side lip 21 from the outside of the hub seal 1.

[0054] Furthermore, as shown in Figure 7, the projection 30 of the side lip 21 covers the tip 25 of the side lip 21 that contacts the contact surface 42a of the flange portion 42 of the slinger 4 from the outer circumference. As a result, the contact portion 5 between the side lip 21 and the flange portion 42 of the slinger 4 is covered from the outer circumference by the projection 30. This prevents foreign matter from passing through the labyrinth seal formed by the gap S1 and reaching the contact portion 5.

[0055] Furthermore, as shown in Figure 7, a gap S2 is formed between the inner circumferential surface 31 or tip surface 33 of the projection 30 and the contact surface 42a of the flange portion 42. The gap S2 is designed to form a labyrinth seal against foreign matter. For example, the width of the gap S2 in the axial x direction and the radial width are set so that the gap S2 forms a labyrinth seal. In this way, the projection 30 covers the contact portion 5 from the outer circumferential side and also forms a labyrinth seal upstream of the contact portion 5 in the foreign matter entry path. As a result, even if foreign matter passes through the labyrinth seal formed by the gap S1, its progress to the contact portion 5 can be suppressed.

[0056] Thus, in the hub seal 1, the advance of foreign matter to the contact area 5 is suppressed by the labyrinth seal (gap S1) located upstream in the foreign matter entry path and the cover of the projection 30 and the labyrinth seal (gap S2) located downstream. As a result, the deterioration of the sealing performance of the side lip 21 due to foreign matter getting caught in the side lip 21 is suppressed.

[0057] On the other hand, the projection 30 of the side lip 21 does not contact the contact surface 42a of the flange portion 42 of the slinger 4. Therefore, the projection 30 does not increase torque resistance.

[0058] Furthermore, even if the tip portion 25 of the side lip 21 wears down over time and no longer contacts the contact surface 42a of the flange portion 42 of the slinger 4, the projection 30 will still contact the contact surface 42a of the slinger 4. This contact of the projection 30 with the contact surface 42a helps to prevent foreign matter from entering the internal space S of the hub bearing 100. In this way, the projection 30 of the side lip 21 can extend the time during which the side lip 21 maintains its sealing performance.

[0059] As described above, according to the hub seal 1 of the embodiment of the present invention, it is possible to improve sealing performance against foreign matter while suppressing an increase in torque resistance.

[0060] Furthermore, in the operating state of the hub seal 1, the projection 30 may be in contact with the contact surface 42a of the flange portion 42 of the slinger 4. As described above, the thickness of the projection 30 is thinner than the thickness of the main body portion 26 and is easily flexible. Therefore, even if the projection 30 comes into contact with the contact surface 42a of the slinger 4, the increase in torque resistance caused by this is not significant. Also, for example, by making the shape of the projection 30 as shown in Figure 6, the torque resistance caused by the projection 30 in contact with the slinger 4 can be reduced. Therefore, in this case as well, the hub seal 1 can improve its sealing performance against foreign matter while suppressing an increase in torque resistance.

[0061] As described above, the sealing device according to the present invention may also be applied to a sealing device 2 which is an outer hub seal of the hub bearing 100. In this case, the sealing device 1 described above does not have a slinger 4, and the contact target portion that the side lip 21 contacts is the annular root surface 105c provided at the root portion of the wheel mounting flange 105b of the hub ring 105 of the inner ring 102. Furthermore, the seal body 3 of the sealing device 1 is shaped to correspond to the portion of the hub bearing 100 to which the sealing device 2 is attached. In addition, the configuration of the side lip 21, such as the projection 30 and the tip portion 25, has the same configuration as the configuration of the side lip 21 with respect to the root surface 105c of the wheel mounting flange 105b with respect to the contact surface 42a of the flange portion 42 of the slinger 4 described above. In this case, in the operating state, the intermediate lip 22 contacts, for example, the root surface 105c, and the grease lip 23 faces the outer circumferential surface of the shaft portion 105a of the inner ring 102. Furthermore, even when the sealing device according to the present invention is applied to the outer sealing device 2 of the hub bearing 100, the sealing device according to the present invention may include a slinger 4. In this case, the slinger 4 is fitted, for example, to the shaft portion 105a of the inner ring 102 and is attached near the portion where the shaft portion 105a and the wheel mounting flange 105b are connected.

[0062] Although the present invention has been described above through the embodiments described above, the technical scope of the present invention is not limited to the scope described in the embodiments above. It will be obvious to those skilled in the art that various modifications or improvements can be made to the embodiments described above. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0063] The embodiments described above are for the purpose of facilitating understanding of the present invention and are not intended to limit its interpretation. Furthermore, the embodiments described above do not limit the scope of application of the present invention, and the present invention may encompass anything as its target application. The components of the above embodiments, as well as their arrangement, materials, conditions, shapes, and sizes, are not limited to those exemplified and can be modified as appropriate. For example, the present invention includes differences that arise in the implementation of manufacturing tolerances, etc. Furthermore, components shown in different embodiments can be partially substituted or combined to the extent that they do not contradict each other in a technical sense. In addition, each configuration can be selectively combined as appropriate to achieve at least some of the problems and effects described above. [Explanation of Symbols]

[0064] 1 Hub seal (sealing device), 2 Sealing device, 3 Seal body (sealing device body), 4 Slinger, 5 Contact surface, 10 Reinforcement ring, 11 Cylindrical part, 11a Fitting part, 11b Gasket support part, 11c, 11d Outer circumference surface, 12 Lip support part, 12a Return part, 12b Lip flange part, 20 Elastic body part, 21 Side lip, 21a Inner circumference surface, 22 Intermediate lip, 22a Tip, 22b Inner circumference surface, 23 Grease lip, 24 Base part, 24a Gasket part, 25 Tip part, 26 Main body part, 26a Outer circumference surface, 26b, 26d Tip, 26c Tip surface, 30 Projection part, 31 Inner circumference surface, 31a Tip, 31b Base end, 32 Outer circumference surface, 32a Tip, 33 Tip surface, 41 41a Fitting part, 42 Contact surface, 42 Flange part (ring part), 42a Contact surface, 42b Outer circumference end, 100 Hub bearing, 101 Outer ring, 101a Inner opening, 101b Outer opening, 101c Inner circumference surface, 102 Inner ring, 103 Bearing ball, 104 Inner ring member, 104a Outer circumference surface, 105 Hub ring, 105a Shaft part, 105b Wheel mounting flange, 105c Base surface, 106 Retainer, 107 Through hole, L Length, L0, L1 Distance, S Internal space, S1, S2 Gap, x Axis, θ Inclination angle

Claims

1. A sealing device for sealing the gap between an outer peripheral member that is rotatable relative to each other with respect to its axis and an inner peripheral member that is at least partially surrounded by the outer peripheral member, The sealing device body is fixed to the outer peripheral member, The sealing device body comprises an annular reinforcing ring around the axis and an elastic body portion attached to the reinforcing ring and formed from an annular elastic material around the axis. The elastic body portion has an annular side lip that extends toward one side in the axial direction and contacts the contact target portion which is a portion provided on the inner circumferential member. The side lip has a tip portion which is an annular end that contacts the part to be contacted, and a projection portion which is an annular part provided on the outer circumference side of the tip portion. The aforementioned projection covers the tip portion from the outer circumference in the radial direction. Sealing device.

2. The projection protrudes in the axial direction from the tip portion to one side. The sealing device according to claim 1.

3. The thickness of the projection is thinner than the thickness of the side lip at the tip. The sealing device according to claim 1.

4. The projection is designed so that when its tip comes into contact with the object to be contacted, it does not come into contact with the object to be contacted. The sealing device according to claim 1.

5. The contact target portion has an annular surface that the tip portion contacts, The angle between the extension direction of the projection and the extension direction of the tip of the seal lip is set based on the angle between the extension direction of the tip of the seal lip in contact with the surface of the contact target and the surface of the contact target. The sealing device according to claim 4.

6. The contact target portion has an annular surface that the tip portion contacts, The length of the projection in the protruding direction is set based on the angle of the extension direction of the tip of the seal lip that contacts the surface of the contact target with respect to the surface of the contact target. The sealing device according to claim 4 or 5.

7. The aforementioned protrusion is designed to contact the portion to be contacted. The sealing device according to claim 1.

8. Further comprising an annular intermediate lip extending toward one side and in contact with the contact target portion, located on the inner circumference side of the side lip, The sealing device according to claim 1.

9. Equipped with a Slinger, The slinger is fixed to the inner circumferential member, and the contact target portion is The sealing device according to claim 1.

10. The slinger has a fitting portion which is a cylindrical portion extending along the axis, and an annular portion which is an annular portion extending radially from one end of the fitting portion. The side lip is configured to contact the annular portion of the slinger. The sealing device according to claim 9.

11. This is a hub seal used in hub bearings. The sealing device according to claim 1.

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