Sealing structure

Abstract

To improve sealability of a bearing space between an outer ring and an inner ring.SOLUTION: A sealing structure (1) comprises a slinger (10) having a first extension part (12), and a sealing member (20) having a base part (23). The sealing member (20) has a second extension part (21) extending from the base part (23), and a third extension part (22) extending from a tip (221) of the second extension part (21) along an inner peripheral surface (121) of the first extension part (12), thereby forming a gap (GP1) with the inner peripheral surface (121).SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Conventionally, for a bearing device having an outer ring and an inner ring, a sealing device that seals a bearing space between the outer ring and the inner ring has been known. For example, Patent Document 1 discloses a sealing device in which an annular sealing member is provided on the outer ring, an annular sheet metal is provided on the inner ring, and a seal lip of the sealing member contacts the sheet metal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2022 / 381293 Summary of the Invention [Problem to be solved by the invention]

[0004] The sealing device disclosed in Patent Document 1 has a structure that makes it easy for muddy water and the like from outside the sealing device to enter between the seal member and the metal plate, and there is room for improvement in the sealing performance of the bearing space between the outer ring and the inner ring. One aspect of the present invention aims to improve the sealing performance of the bearing space between the outer ring and the inner ring. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, a sealing structure according to one embodiment of the present invention is provided in a bearing device having an outer ring and an inner ring, and seals the bearing space between the outer ring and the inner ring. The sealing structure comprises: a slinger having a circular plate portion fixed to a flange portion extending radially outward from the shaft portion of the inner ring and a first extension portion extending from the circular plate portion toward the opposite side of the flange portion; and a sealing member having a base portion provided on the outer ring and a lip portion extending from the base portion toward the flange portion and elastically contacting the slinger. The sealing member has a second extension portion extending radially from the base portion, and a third extension portion extending from the tip of the second extension portion along the inner surface of the first extension portion, thereby forming a gap with the inner surface of the first extension portion. [Effects of the Invention]

[0006] According to one aspect of the present invention, the sealing performance of the bearing space between the outer ring and the inner ring can be improved. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view showing an example of a cross-sectional configuration of a bearing device according to an embodiment of the present invention. [Figure 2] 2 is a cross-sectional view showing an example of a cross-sectional configuration of a sealing structure provided in the bearing device shown in FIG. 1. FIG. [Figure 3] FIG. 10 is a cross-sectional view showing an example of a cross-sectional configuration of a sealing structure according to a first modified example of the present invention. [Figure 4] FIG. 10 is a cross-sectional view showing an example of a cross-sectional configuration of a sealing structure according to a second modified example of the present invention. [Figure 5] FIG. 10 is a cross-sectional view showing an example of a cross-sectional configuration of a sealing structure according to a third modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0008] <Configuration of bearing device 100> Fig. 1 is a cross-sectional view showing an example of the cross-sectional configuration of a bearing device 100 according to an embodiment of the present invention. In Fig. 1, the direction from the body of the automobile toward the wheels is the positive X-axis direction, the direction perpendicular to the ground on which the automobile is placed is the positive Z-axis direction, and the direction perpendicular to the X-axis and Z-axis directions is the Y-axis direction. The X-axis and Z-axis directions are mutually orthogonal. The automobile body and wheels are not shown in Fig. 1.

[0009] As shown in FIG. 1, the bearing device 100 includes an outer ring 2, an inner ring 3, and a plurality of rolling elements 4. The outer ring 2 is fixed to the body of the automobile. The inner ring 3 has a hub ring 3A and an inner ring member 3B. The inner ring 3 is rotatable around an axis L relative to the outer ring 2. A drive shaft (not shown) is coaxially spline-fitted to the hub ring 3A. The inner ring member 3B is fitted to the negative side of the X-axis of the hub ring 3A.

[0010] The rolling elements 4 are balls provided between the outer ring 2 and the inner ring 3. The rolling elements 4 are arranged in two rows in the X-axis direction. A bearing space SP1, which is an annular space, is formed between the outer ring 2 and the inner ring 3. Within the bearing space SP1, the rolling elements 4 are held by a retainer 4A and are provided rollably between the race 2A of the outer ring 2 and the race 3A1 of the hub ring 3A and the race 3B1 of the inner ring member 3B.

[0011] The hub ring 3A has a cylindrical shaft portion 3A2 and a flange portion 3A4 that extends from the shaft portion 3A2 via a rising base portion 3A3 to the radially outward direction of the inner ring 3. A wheel is fixed to the flange portion 3A4 with bolts 3A5 and nuts (not shown). The radial direction of the inner ring 3 is the radial direction D1 shown in FIG. 1, which is the direction from the axis L of the inner ring 3 toward the outside. The radial direction of the outer ring 2 is the same as the radial direction of the inner ring 3. Hereinafter, the radial direction of the inner ring 3 may be simply referred to as the radial direction.

[0012] A sealing structure 1 is provided between the outer ring 2 and the hub wheel 3A on the positive side of the X-axis in the bearing space SP1. Furthermore, a sealing structure 5 is provided between the outer ring 2 and the inner ring member 3B on the negative side of the X-axis in the bearing space SP1. This seals both sides of the bearing space SP1 in the X-axis direction by the sealing structures 1 and 5. This prevents muddy water and the like from entering the bearing space SP1 and also prevents lubricant such as grease filled in the bearing space SP1 from leaking out of the bearing space SP1. The sealing structure 1 will be described later. The sealing structure 5 may have the same structure as the sealing structure 1.

[0013] <Configuration of Sealing Structure 1> Fig. 2 is a cross-sectional view showing an example of the cross-sectional configuration of the sealing structure 1 provided in the bearing device 100 shown in Fig. 1. Fig. 2 is an enlarged view of the part surrounded by dotted line A1 shown in Fig. 1. The sealing structure 1 is a structure that seals the bearing space SP1 between the outer ring 2 and the inner ring 3. As shown in Fig. 2, the sealing structure 1 includes a slinger 10 and a seal member 20.

[0014] The slinger 10 has a disk portion 11, a first extension portion 12, and a fourth extension portion 13. The slinger 10 is a metal member that is fitted to the hub wheel 3A. The disk portion 11 is fixed to a flange portion 3A4 that extends from the shaft portion 3A2 of the inner ring 3 radially outward from the inner ring 3. The disk portion 11 is a portion of the slinger 10 that extends along the radial direction D1.

[0015] The first extending portion 12 extends from the radially outer end of the disk portion 11 toward the side opposite the flange portion 3A4. In other words, the first extending portion 12 extends from the radially outer end of the disk portion 11 toward the negative direction of the X-axis. The fourth extending portion 13 extends from the radially inner end of the disk portion 11 toward the side opposite the flange portion 3A4. In other words, the fourth extending portion 13 extends from the radially inner end of the disk portion 11 toward the negative direction of the X-axis. The fourth extending portion 13 is fitted into and fixed to a step portion 3A6 provided between the shaft portion 3A2 and the flange portion 3A4. This fixes the disk portion 11 to the flange portion 3A4.

[0016] The sealing member 20 has a second extension portion 21, a third extension portion 22, a base portion 23, and lip portions 24, 25. Portions of the sealing member 20 other than the core metal 30 are made of an elastic material such as rubber. The base portion 23 has an elastic portion 23E and the core metal 30. The base portion 23 is provided on the outer ring 2. Specifically, the elastic portion 23E of the base portion 23 is fixed to the core metal 30 that is fitted into the outer ring 2.

[0017] Core metal 30 is a metal member consisting of a cylindrical portion fitted onto the outer peripheral surface of outer ring 2 on the side of corner 2B, and a disk portion extending along the end face of outer ring 2 on the positive X-axis direction side. Corner 2B is a corner on the radially outer side of outer ring 2 and on the positive X-axis direction side. End 31 of core metal 30 on the bearing space SP1 side is located radially outward of corner 2C of outer ring 2. Corner 2C is a corner on the radially inner side of outer ring 2 and on the positive X-axis direction side.

[0018] Elastic portion 23E is a portion of base portion 23 other than core metal 30. The shape of elastic portion 23E follows the outer peripheral surface of corner portion 2B of outer ring 2 and the end face of outer ring 2 on the positive X-axis direction side. In other words, elastic portion 23E also follows the shape of core metal 30. Elastic portion 23E covers core metal 30 from the side of core metal 30 opposite to the outer ring 2 side.

[0019] Lip portion 24 extends from base portion 23 toward flange portion 3A4 and elastically contacts disc portion 11 of slinger 10. Lip portion 25 extends from base portion 23 toward shaft portion 3A2 and elastically contacts fourth extension portion 13 of slinger 10. Lip portions 24, 25 elastically contact slinger 10, thereby preventing muddy water and the like from outside sealing structure 1 from entering bearing space SP1.

[0020] The lip portions 24, 25 are formed at an end 231 on the bearing space SP1 side of the elastic portion 23E of the base portion 23. The end 231 is an end opposite to an end 232 on the external space side of the elastic portion 23E of the base portion 23. The end 231 is disposed radially outward of the corner portion 2C of the outer ring 2.

[0021] By forming lip portions 24, 25 on end portion 231 of elastic portion 23E on the bearing space SP1 side, lip portions 24, 25 can prevent muddy water or the like that has entered space SP2 between slinger 10 and seal member 20 from entering bearing space SP1. Therefore, in addition to lip portions 24, 25 that elastically contact slinger 10, second extension portion 21 and third extension portion 22 can improve the sealing performance of bearing space SP1 between outer ring 2 and inner ring 3. Details of second extension portion 21 and third extension portion 22 will be described later.

[0022] The second extension portion 21 extends radially outward from the base portion 23. The third extension portion 22 extends from the tip 221 of the second extension portion 21 along the inner circumferential surface 121 of the first extension portion 12, thereby forming a gap GP1 between the third extension portion 22 and the inner circumferential surface 121 of the first extension portion 12. The structure in which the gap GP1 is formed by the first extension portion 12 and the third extension portion 22 is a labyrinth structure. The gap GP1 communicates with a space SP2 between the disc portion 11 of the slinger 10 and the base portion 23 and second extension portion 21 of the seal member 20.

[0023] Consider a case in which the second extension portion 21 extends radially outward beyond the first extension portion 12, and the third extension portion 22 extends from the tip 221 of the second extension portion 21 along the outer peripheral surface of the first extension portion 12. In this case, when the inner ring 3 rotates, the third extension portion 22 is likely to swing due to its length and weight, and the third extension portion 22 comes into contact with the first extension portion 12, increasing the torque applied to the third extension portion 22.

[0024] 2, the third extension portion 22 extends along the inner peripheral surface 121 of the first extension portion 12, and therefore the third extension portion 22 is less likely to vibrate when the inner ring 3 rotates. This reduces the chance of the third extension portion 22 coming into contact with the first extension portion 12, and suppresses the torque applied to the third extension portion 22.

[0025] Distance DS1 between the portion of outer ring 2 where base portion 23 is provided and the surface of third extension portion 22 facing inner circumferential surface 121 of first extension portion 12 is preferably 2.0 mm or more and 4.0 mm or less. This allows the distance from the portion of outer ring 2 where base portion 23 is provided to gap GP1 to be sufficiently long.

[0026] This sufficiently reduces the intrusion of muddy water and the like from outside the sealing structure 1 into the space SP2 between the slinger 10 and the seal member 20. When the automobile is traveling, muddy water and the like from outside the sealing structure 1 strikes the second extension portion 21 and the base portion 23 from the upper left toward the lower right in Fig. 2. The distance DS1 is the distance along the radial direction.

[0027] Furthermore, it is preferable that the distance DS3 of the gap GP1 between the inner circumferential surface 121 of the first extension portion 12 and the third extension portion 22 is 0.1 mm or more and 1.0 mm or less. This makes it possible to form a labyrinth seal that prevents muddy water and the like from entering the sealed structure 1 through the gap GP1, and also to form a gap GP1 large enough to allow muddy water and the like that has entered to be discharged to the outside.

[0028] As described above, the seal member 20 has the second extension portion 21 that extends from the base portion 23 in the radial direction D1 of the inner ring 3. This allows muddy water and the like from outside the sealing structure 1 to hit the second extension portion 21, thereby reducing the intrusion of muddy water and the like into the space SP2 between the slinger 10 and the seal member 20.

[0029] Additionally, the seal member 20 has a third extension portion 22 that extends from the tip of the second extension portion 21 along the inner circumferential surface 121 of the first extension portion 12. This prevents muddy water and the like from outside the sealing structure 1 from entering the gap GP1 between the first extension portion 12 and the third extension portion 22, reducing the possibility of muddy water and the like reaching the space SP2 between the slinger 10 and the seal member 20. Therefore, in addition to the lip portions 24, 25 that elastically contact the slinger 10, the second extension portion 21 and the third extension portion 22 can improve the sealing performance of the bearing space SP1 between the outer ring 2 and the inner ring 3.

[0030] Distance DS2 between the tip of lip portion 24 when not in contact with disc portion 11 of slinger 10 and tip 211 of third extension 22 is preferably 4.0 mm or more and 9.0 mm or less. This allows the distance from gap GP1 between inner circumferential surface 121 of first extension 12 and third extension 22 to lip portion 24 to be sufficiently long, and allows space SP2 between slinger 10 and seal member 20 to be sufficiently wide.

[0031] This reduces the possibility that muddy water or the like from outside the sealing structure 1 will reach the lip portion 24, and reduces the likelihood of it hitting the lip portion 24, thereby reducing wear on the lip portion 24 due to muddy water or the like. This effect also contributes to achieving, for example, Goal 12 of the Sustainable Development Goals (SDGs) advocated by the United Nations, "Ensure sustainable consumption and production patterns." In addition, before the muddy water or the like reaches the lip portion 24, it can be discharged from the gap GP1 to the outside of the sealing structure 1. The distance DS2 is a distance along the radial direction.

[0032] A recess 26 is formed on the slinger 10 side of the sealing member 20. The surface of the second extension portion 21 facing the flange portion 3A4 forms a bottom surface 262 of the recess 26, and the surface of the third extension portion 22 opposite the first extension portion 12 side forms a side wall 261 of the recess 26. The surface of the elastic portion 23E formed radially outward from the corner 233 of the elastic portion 23E of the base portion 23 formed along the corner 2B of the outer ring 2 forms the side wall 263 of the recess 26.

[0033] As described above, the recess 26 is formed on the slinger 10 side of the sealing member 20, and the third extension portion 22 forms the side wall 261 of the recess 26. As a result, even if muddy water or the like enters through the gap GP1 between the first extension portion 12 and the third extension portion 22, the muddy water or the like enters the recess 26, thereby reducing the possibility that the muddy water or the like will reach the lip portion 24.

[0034] On the side of the third extending portion 22 opposite to the first extending portion 12 side, an inclined surface SF1 is formed that slopes from the tip 211 of the third extending portion 22 toward the second extending portion 21. Specifically, the inclined surface SF1 is formed on the side wall 261 of the recess 26. The inclined surface SF1 is formed so that the third extending portion 22 becomes thicker from the tip 211 of the third extending portion 22 toward the side opposite to the flange portion 3A4 side. In other words, the inclined surface SF1 is formed so that the third extending portion 22 becomes thicker toward the negative direction of the X axis.

[0035] When the inner ring 3 rotates, an air flow occurs between the slinger 10 and the seal member 20, causing muddy water and other liquids between the slinger 10 and the seal member 20 to flow down the inclined surface SF1 on the ground side (the negative Z-axis direction side) and be discharged to the outside of the sealed structure 1 through the gap GP1 between the first extension portion 12 and the third extension portion 22. This allows for the muddy water and other liquids that have entered between the slinger 10 and the seal member 20 to be urged to be discharged to the outside of the sealed structure 1.

[0036] <Variation 1> 3 is a cross-sectional view showing an example of the cross-sectional configuration of a sealing structure 1A according to Modification 1 of the present invention. The sealing structure 1A differs from the sealing structure 1 in that the sealing member 20 is changed to a sealing member 20A. The sealing member 20A also differs from the sealing member 20 in that a protrusion 27 is formed.

[0037] On the slinger 10 side of seal member 20A, protrusion 27 is formed between third extension 22 and lip portion 24, protruding from base portion 23 toward slinger 10. By forming protrusion 27 on base portion 23, side wall 263 relating to recess 26 of seal member 20A is larger than side wall 263 relating to recess 26 of seal member 20. Protrusion 27 is not in contact with disc portion 11 of slinger 10.

[0038] As a result, if muddy water or the like enters through the gap GP1 between the first extension portion 12 and the third extension portion 22, the muddy water or the like will enter between the third extension portion 22 and the protrusion portion 27, thereby reducing the possibility of the muddy water or the like reaching the lip portion 24.

[0039] <Variation 2> 4 is a cross-sectional view showing an example of a cross-sectional configuration of a sealing structure 1B according to Modification 2 of the present invention. The sealing structure 1B differs from the sealing structure 1 in that the sealing member 20 is changed to a sealing member 20B. The sealing member 20B also differs from the sealing member 20 in that the third extension portion 22 is changed to a third extension portion 22B.

[0040] As shown in Fig. 4, the first distance IS1 between the third extension portion 22B and the disk portion 11 of the slinger 10 is substantially the same as the second distance IS2 between the third extension portion 22B and the first extension portion 12 of the slinger 10. "Substantially the same" means that a difference between the first distance IS1 and the second distance IS2 caused by deformation of the seal member 20B is allowed. On the other hand, in the sealing structure 1, as shown in Fig. 2, the first distance between the third extension portion 22B and the disk portion 11 of the slinger 10 is different from the second distance of the gap GP1 between the third extension portion 22 and the first extension portion 12 of the slinger 10.

[0041] Therefore, in sealing structure 1B, gap GP1 is formed between third extension portion 22B and disc portion 11, compared to sealing structure 1. Therefore, in sealing structure 1B, a longer labyrinth is formed by gap GP1, compared to sealing structure 1, and it is possible to further reduce the intrusion of muddy water and the like into space SP2 between slinger 10 and seal member 20B.

[0042] <Variation 3> 5 is a cross-sectional view showing an example of a cross-sectional configuration of a sealing structure 1C according to Modification 3 of the present invention. The sealing structure 1C differs from the sealing structure 1 in that the sealing member 20 is changed to a sealing member 20C and that there is no step portion 3A6 between the shaft portion 3A2 and the flange portion 3A4. The sealing member 20C differs from the sealing member 20 in that the base portion 23 is changed to a base portion 23C.

[0043] An end 31C of core 30C of base portion 23C on the bearing space SP1 side is arranged radially inward of corner 2C of outer ring 2. Core 30C is provided along the outer peripheral surface of corner 2B side of outer ring 2 and along the end face on the X-axis positive side of outer ring 2. In addition, an end 231C of elastic portion 23CE of base portion 23C on the bearing space SP1 side is arranged radially inward of corner 2C of outer ring 2.

[0044] This allows the lips 24, 25 to be brought into elastic contact with the slinger 10 when there is no step 3A6 between the shaft 3A2 and the flange 3A4. This prevents muddy water and the like from entering the bearing space SP1 from the space SP2 between the slinger 10 and the seal member 20C.

[0045] A wall surface SF2 may be formed on the third extending portion 22C of the seal member 20C on the side opposite to the first extending portion 12. The wall surface SF2 is formed along the X-axis direction and is formed approximately perpendicular to the YZ plane.

[0046] 〔summary〕 The sealing structure of aspect 1 of the present invention is a sealing structure provided in a bearing device having an outer ring and an inner ring, and seals the bearing space between the outer ring and the inner ring. The sealing structure comprises: a slinger having a circular plate portion fixed to a flange portion extending from the shaft portion of the inner ring radially outward of the inner ring, and a first extension portion extending from the circular plate portion toward the opposite side of the flange portion; and a sealing member having a base portion provided on the outer ring and a lip portion extending from the base portion toward the flange portion and elastically contacting the slinger. The sealing member has a second extension portion extending radially from the base portion, and a third extension portion extending from the tip of the second extension portion along the inner surface of the first extension portion, thereby forming a gap with the inner surface of the first extension portion.

[0047] The sealing structure according to aspect 2 of the present invention may be configured in the above-mentioned aspect 1 such that a recess is formed on the slinger side of the sealing member, and the third extension portion forms a side wall of the recess.

[0048] The sealing structure according to aspect 3 of the present invention may be configured such that, in aspect 1 or 2 above, an inclined surface is formed on the side of the third extension portion opposite the first extension portion, sloping from the tip of the third extension portion toward the second extension portion.

[0049] The sealing structure according to aspect 4 of the present invention may be configured such that, in any of aspects 1 to 3 above, a protrusion is formed on the slinger side of the sealing member between the third extension portion and the lip portion, protruding from the base portion toward the slinger side.

[0050] A sealing structure according to a fifth aspect of the present invention may be configured in any one of the first to fourth aspects, wherein the lip portion is formed at an end of the base portion on the bearing space side.

[0051] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Configurations obtained by appropriately combining multiple technical means disclosed in the embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0052] 1, 1A, 1B, 1C Sealed structure 2 Outer ring 3 Inner ring 3A2 Shaft 3A4 Flange 10 Slinger 11 disk portion 12 first extension portion 20, 20A, 20B, 20C sealing member 21 second extension portion 22, 22B, 22C: Third extension portion 23, 23C: Base portion 24, 25 Lip portion 26 Recessed portion 27 Projection 30, 30C Core metal 100 bearing device 121 inner peripheral surface 211, 221 Tip 231, 231C End 261 Side wall D1 radial direction GP1 Gap SF1 Inclined surface SP1 bearing space

Claims

1. A sealing structure provided in a bearing device having an outer ring and an inner ring, for sealing a bearing space between the outer ring and the inner ring, a slinger including: a disk portion fixed to a flange portion extending from a shaft portion of the inner ring radially outward of the inner ring; and a first extension portion extending from the disk portion toward an opposite side to the flange portion; a sealing member including a base portion provided on the outer ring and a lip portion extending from the base portion toward the flange portion and elastically contacting the slinger, The sealing member is a second extension portion extending from the base portion in the radial direction; A sealing structure characterized by having a third extension portion that extends from the tip of the second extension portion along the inner surface of the first extension portion, thereby forming a gap with the inner surface of the first extension portion.

2. A recess is formed on the slinger side of the sealing member, The sealing structure according to claim 1 , wherein the third extension forms a side wall of the recess.

3. The sealing structure described in claim 1 or 2, characterized in that an inclined surface is formed on the opposite side of the third extension portion from the first extension portion, the inclined surface inclining from the tip of the third extension portion toward the second extension portion.

4. A sealing structure as described in claim 1 or 2, characterized in that a protrusion protruding from the base portion toward the slinger is formed on the slinger side of the sealing member between the third extension portion and the lip portion.

5. 3. The sealing structure according to claim 1, wherein the lip portion is formed at an end of the base portion on the side of the bearing space.

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