Sealing device and rolling bearing device

Abstract

A sealing device according to the present invention is provided between an external member and an internal member and comprises: a slinger having a first cylindrical part that is fixed to the outer circumferential surface of the internal member, a first disc part that extends toward the radial-direction outer side from the end on one axial-direction side of the first cylindrical part, and a second cylindrical part that extends toward the other axial-direction side from the end on the radial-direction outer side of the first disc part; and a seal member having a third cylindrical part that is fixed to the inner circumferential surface of the external member, a second disc part that extends toward the radial-direction inner side from the end on the other axial-direction side of the third cylindrical part, and a seal lip that is provided on the second disc part and is in sliding contact with the slinger. The outer circumferential surface of the second cylindrical part includes a first inclined surface that increases in size toward the one axial-direction side. The inner circumferential surface of the third cylindrical part includes a second inclined surface that faces the first inclined surface in the radial direction and increases in size toward the one axial-direction side. The first inclined surface is formed from a polymer material.

Description

[Technical Field]

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

[0002] Conventionally, sealing devices used in wheel bearing devices are known (for example, see Patent Document 1). Wheel bearing devices are devices that support the wheels of an automobile or the like. The wheel bearing device includes an outer member and an inner member that are concentrically arranged, and a plurality of rolling elements that are arranged between the outer member and the inner member. The sealing device is provided between the outer member and the inner member, and prevents foreign matter such as muddy water from entering the annular space formed between the outer member and the inner member (i.e., the space inside the bearing where the rolling elements are provided). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-51597 Summary of the Invention [Problem to be solved by the invention]

[0004] Fig. 6 is a diagram illustrating the problem to be solved by the present invention. Fig. 6 shows an axial cross-sectional view of a sealing device 90 according to Patent Document 1. The sealing device 90 is provided in a wheel bearing assembly to prevent muddy water and the like from entering from an external space S91 to an internal space S92. The sealing device 90 has a slinger 91 provided at an inner end of an inner member 95, and a seal plate 92 provided at an inner end of an outer member 96.

[0005] The slinger 91 has a slinger fitting portion 91a that fits into the inner member 95, a standing plate portion 91b that extends radially outward from the end of the slinger fitting portion 91a, and a cylindrical portion 91c that is bent axially from the end of the standing plate portion 91b. The seal plate 92 has a seal plate fitting portion 92a that fits into the outer member 96, a lip support portion 92b that extends radially inward from the end of the seal plate fitting portion 92a, and an axial lip 92c, a radial lip 92d, and a grease lip 92e that are provided on the lip support portion 92b. An outer peripheral surface 93 of the cylindrical portion 91c and an inner peripheral surface 94 of the seal plate fitting portion 92a are each surfaces parallel to the axial direction.

[0006] The sealing device 90 is formed with a space S93 for temporarily receiving muddy water and the like. The radial distance from the base to the tip of the axial lip 92c is made relatively large, thereby preventing muddy water and the like that has entered the space S93 from reaching the tip of the axial lip 92c. Furthermore, the radial lip 92d and the grease lip 92e come into contact with or are close to the slinger 91 via an oil film, thereby preventing muddy water and the like in the space S93 from entering the internal space S92.

[0007] The conventional sealing device 90 shown in Fig. 6 is designed on the assumption that muddy water or the like will enter the space S93 from the external space S91, and multiple lips 92c to 92e prevent the muddy water or the like from the space S93 from entering the internal space S92. However, if a large amount of muddy water or the like enters the space S93, it becomes difficult to completely prevent the muddy water or the like from entering the internal space S92. Furthermore, if a large amount of muddy water or the like enters the space S93, for example, mud may become caught between the lips 92c to 92e and the slinger 91, causing wear of the lips 92c to 92e. If the sealing device 90 deteriorates due to the intrusion of muddy water or the like into the space S93, it will no longer be possible to sufficiently prevent the intrusion of muddy water or the like into the internal space S92.

[0008] Here, in order to prevent muddy water and the like from entering the space S93, it is conceivable to narrow the gap between the outer peripheral surface 93 and the inner peripheral surface 94 or to make the gap between the outer peripheral surface 93 and the inner peripheral surface 94 uneven (labyrinth-shaped). However, if the gap between the outer peripheral surface 93 and the inner peripheral surface 94 is narrowed, there is a risk that foreign matter such as mud will get caught between the outer peripheral surface 93 and the inner peripheral surface 94 and damage the sealing device 90.

[0009] Furthermore, even if the above-described structure is adopted, it is not possible to completely prevent the intrusion of muddy water and the like into the space S93, and muddy water and the like will invade the space S93. Furthermore, if the above-described structure is adopted, it becomes difficult to expel muddy water and the like that has once invaded the space S93 into the external space S91, and there is a risk that muddy water and the like will accumulate in the space S93 over time. As described above, the conventional sealing device 90 has a problem in that the more efforts are made to prevent the intrusion of muddy water and the like into the space S93, the more difficult it becomes to discharge muddy water and the like from the space S93, and it has not been possible to sufficiently prevent deterioration of the sealing device 90 due to the intrusion of muddy water and the like.

[0010] Therefore, an object of the present disclosure is to provide a sealing device and a rolling bearing device that can suppress deterioration due to the intrusion of muddy water and the like. [Means for solving the problem]

[0011] The sealing device of the present invention is a sealing device disposed between an outer member having an outer ring raceway on its inner peripheral surface and an inner member having an inner ring raceway on its outer peripheral surface and rotating relative to the outer member, and comprises: a slinger having a first cylindrical portion fixed to the outer peripheral surface of the inner member, a first circular plate portion extending radially outward from one axial end of the first cylindrical portion, and a second cylindrical portion extending from the radially outer end of the first circular plate portion to the other axial side; and a seal member having a third cylindrical portion fixed to the inner peripheral surface of the outer member, a second circular plate portion extending radially inward from the other axial end of the third cylindrical portion, and a seal lip provided on the second circular plate portion and in sliding contact with the slinger, wherein the outer peripheral surface of the second cylindrical portion includes a first inclined surface that increases in diameter toward one axial side, and the inner peripheral surface of the third cylindrical portion includes a second inclined surface that is radially opposite the first inclined surface and increases in diameter toward one axial side, and the first inclined surface is formed of a polymeric material. [Effects of the Invention]

[0012] According to the invention of the present disclosure, deterioration of the sealing device due to the intrusion of muddy water or the like can be suppressed. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view showing a rolling bearing device according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing a sealing device according to the embodiment. [Figure 3] FIG. 3 is an enlarged view of a portion of the sealing device of FIG. 2. [Figure 4] FIG. 10 is an enlarged view of a portion of a sealing device according to a modified example. [Figure 5] FIG. 10 is an enlarged view of a portion of a sealing device according to a modified example. [Figure 6] FIG. 1 is a diagram illustrating a problem to be solved by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] [Description of the embodiment of the present invention] The gist of the embodiments of the present invention includes at least the following.

[0015] (1) The sealing device of the present invention is a sealing device provided between an outer member having an outer ring raceway on its inner peripheral surface and an inner member having an inner ring raceway on its outer peripheral surface and rotating relative to the outer member, and includes a slinger having a first cylindrical portion fixed to the outer peripheral surface of the inner member, a first circular plate portion extending radially outward from one axial end of the first cylindrical portion, and a second cylindrical portion extending from the radially outer end of the first circular plate portion to the other axial end, a third cylindrical portion fixed to the inner peripheral surface of the outer member, a sealing member having a second circular plate portion extending radially inward from the other axial end of the third cylindrical portion, and a seal lip provided on the second circular plate portion that slides against the slinger, wherein the outer peripheral surface of the second cylindrical portion includes a first inclined surface that widens in diameter toward one axial side, and the inner peripheral surface of the third cylindrical portion includes a second inclined surface that is radially opposite the first inclined surface and widens in diameter toward one axial side, and the first inclined surface is formed of a polymeric material.

[0016] Because both the first inclined surface and the second inclined surface increase in diameter toward one axial side, the gap between the first inclined surface and the second inclined surface is inclined radially outward toward one axial side. Therefore, when the inner member rotates relative to the outer member, centrifugal force generates a fluid flow toward the external space of the sealing device. As a result, the intrusion of muddy water and the like into the sealing device can be suppressed while the muddy water and the like that has once invaded can be more effectively discharged. Furthermore, because the first inclined surface is made of a polymeric material, it has higher water repellency than metal. Therefore, the intrusion of muddy water and the like can be more effectively suppressed while the muddy water and the like that has once invaded can be more effectively discharged. This suppresses deterioration of the sealing device due to the intrusion of muddy water and the like.

[0017] (2) Preferably, the inner peripheral surface of the second cylindrical portion includes a parallel surface parallel to the axial direction or a third inclined surface whose diameter decreases toward one side in the axial direction.

[0018] With this configuration, when the inner member rotates relative to the outer member, it is possible to prevent the muddy water collected on the inner circumferential surface of the second cylindrical portion from being forced toward the first circular plate portion, thereby further preventing the intrusion of muddy water.

[0019] (3) Preferably, a first inclination angle of the first inclined surface relative to the axial direction is larger than a second inclination angle of the second inclined surface relative to the axial direction.

[0020] With this configuration, when the inner member rotates relative to the outer member, the flow of fluid toward the external space can be made faster at the opening on the external space side formed by the first inclined surface and the second inclined surface. This allows muddy water and the like to be forcefully discharged from the opening to the external space, thereby preventing clogging of the opening with foreign matter and preventing the sealing device's ability to discharge muddy water and the like from deteriorating over time. Furthermore, because the opening on the external space side is narrow, the intrusion of muddy water and the like can be further prevented.

[0021] (4) Preferably, one axial end of the third cylindrical portion does not intersect with an imaginary line extending axially to one side from a center line in the radial direction between the first inclined surface and the second inclined surface.

[0022] With this configuration, it is possible to prevent the flow of fluid toward the external space from being blocked by the end of the third cylindrical portion, thereby improving the ability to discharge muddy water and the like in the sealing device.

[0023] (5) The rolling bearing device of the present invention is a rolling bearing device comprising the outer member, the inner member, a plurality of rolling elements arranged between the outer ring raceway and the inner ring raceway, and any one of the sealing devices (1) to (4).

[0024] The rolling bearing device described above is provided with any one of the sealing devices (1) to (4) described above, and therefore deterioration of the sealing device due to the intrusion of muddy water or the like can be suppressed.

[0025] [Details of the embodiment of the present invention] Hereinafter, details of embodiments of the present invention will be described with reference to the drawings.

[0026] [Overall configuration of rolling bearing device] FIG. 1 is a cross-sectional view showing a rolling bearing device 10 according to an embodiment. The rolling bearing device 10 is a wheel bearing device for supporting a wheel of a vehicle such as an automobile, and is also called a hub unit. The rolling bearing device 10 is attached to a suspension device (also called a knuckle) provided on the vehicle, and supports the wheel so that it can rotate. The rolling bearing device 10 comprises an outer member 11, an inner member 12, a plurality of rolling elements 13, a cage 14, and two sealing devices 15 and 16.

[0027] Here, the direction parallel to the center line C1 of the rolling bearing device 10 is referred to as the "axial direction." When the rolling bearing device 10 is attached to a suspension, the center side of the vehicle body (also referred to as the vehicle inner side, corresponding to the right side in FIG. 1) is referred to as the "one axial side," and the wheel side (also referred to as the vehicle outer side, corresponding to the left side in FIG. 1) is referred to as the "other axial side." Furthermore, the direction perpendicular to the axial direction is referred to as the "radial direction." The side approaching the center line C1 is referred to as the "radially inner side," and the side away from the center line C1 is referred to as the "radially outer side."

[0028] The outer member 11 is also called an outer ring member and is a substantially cylindrical member provided with its axis aligned with the center line C1. The outer member 11 has two outer ring raceways 11b1 and 11b2 on its inner peripheral surface 11a.

[0029] The inner member 12 is a substantially cylindrical member with its axis aligned with the center line C1. The inner member 12 has a hub axle 21 and an inner ring 22 attached to one axial side of the hub axle 21. The hub axle 21 is also referred to as the inner shaft. A flange 21a for securing a wheel is formed on the other axial side of the hub axle 21. The inner member 12 has two inner ring raceways 12b1, 12b2 on its outer peripheral surface 12a. The inner ring raceway 12b1 on one axial side is formed on the outer peripheral surface of the inner ring 22. The inner ring raceway 12b2 on the other axial side is formed on the outer peripheral surface of the hub axle 21.

[0030] The plurality of rolling elements 13 are arranged in two axial rows. The plurality of rolling elements 13 arranged between the outer ring raceway 11b1 and the inner ring raceway 12b1 constitute one axial row, and the plurality of rolling elements 13 arranged between the outer ring raceway 11b2 and the inner ring raceway 12b2 constitute the other axial row. The cage 14 holds the plurality of rolling elements 13. The plurality of rolling elements 13 roll between the outer ring raceways 11b1, 11b2 and the inner ring raceways 12b1, 12b2, causing the inner member 12 to rotate relative to the outer member 11 about the center line C1. In this embodiment, the outer member 11 is a fixed member fixed to the suspension, and the inner member 12 is a rotating member that rotates relative to the suspension (and the vehicle body).

[0031] The sealing devices 15 and 16 are provided between the outer member 11 and the inner member 12. The sealing device 15 is a vehicle inner-side sealing device provided on one axial side of the outer ring raceway 11b1 and the inner ring raceway 12b1. The sealing device 16 is a vehicle outer-side sealing device provided on the other axial side of the outer ring raceway 11b2 and the inner ring raceway 12b2. The sealing devices 15 and 16 are devices for preventing muddy water and the like from entering the internal space S2 formed between the outer member 11 and the inner member 12 from the external space S1 of the rolling bearing device 10. The internal space S2 is the internal space of the rolling bearing device 10 surrounded by the inner peripheral surface 11a of the outer member 11, the outer peripheral surface 12a of the inner member 12, the sealing device 15, and the sealing device 16.

[0032] [Configuration of sealing device] 2 is a cross-sectional view showing one axial side (vehicle inner side) of the sealing device 15. One axial side (right side in FIG. 2) of the sealing device 15 is the exterior space S1, and the other axial side (left side in FIG. 2) of the sealing device 15 is the interior space S2. The sealing device 15 has a slinger 30 and a seal member 40.

[0033] Slinger 30 has a shape including a first cylindrical portion 31, a first disc portion 32, and a second cylindrical portion 33. Slinger 30 is made of a metal member 30a made of metal and a polymer member 30b made of a polymer material. Metal member 30a is a member for increasing the strength of slinger 30 and is formed from a steel material such as stainless steel.

[0034] The polymer member 30b is a member containing a polymer material, for example, fluorine rubber such as nitrile rubber (NBR) or vinylidene fluoride rubber (FKM), or polyamide (PA) such as nylon. The polymer member 30b has the function of improving the adhesion of the slinger 30 and the drainage performance described below. The polymer member 30b is a member with higher elasticity than the metal member 30a.

[0035] Furthermore, the contact angle of the polymer member 30b with water is larger than the contact angle of the metal member 30a with water. For example, if the metal member 30a is made of stainless steel, the contact angle of the metal member 30a with water is approximately 70 degrees. In this case, the polymer member 30b is made of a hydrophobic material whose contact angle with water is larger than 70 degrees. In other words, the polymer member 30b has the property of being less susceptible to water than the metal member 30a.

[0036] The first cylindrical portion 31 is a cylindrical portion fixed to the outer peripheral surface 12a of the inner member 12 (more specifically, the inner ring 22). The first cylindrical portion 31 is fitted to the outer peripheral surface 12a with a predetermined interference. The first cylindrical portion 31 is formed of, for example, a metal member 30a, but may also include a polymer member 30b.

[0037] The first circular plate portion 32 is a circular plate-shaped portion extending radially outward from one axial end of the first cylindrical portion 31. The first circular plate portion 32 has a metal portion 32a and a polymer portion 32b that covers one axial side of the metal portion 32a. The metal portion 32a is formed from the metal member 30a, and the polymer portion 32b is formed from the polymer member 30b.

[0038] The second cylindrical portion 33 is a cylindrical portion extending from the radially outer end of the first circular plate portion 32 toward the other axial side. The second cylindrical portion 33 has a metal portion 33a, a polymer portion 33b covering the radially outer side of the metal portion 33a, and a polymer portion 33c covering the other axial side of the metal portion 33a. The metal portion 33a is formed from the metal member 30a, and the polymer portions 33b and 33c are formed from the polymer member 30b.

[0039] The seal member 40 has a shape including a third cylindrical portion 41, a second disc portion 42, and a seal lip 43. The seal member 40 is made of a metal member 40a made of metal and a polymer member 40b made of a polymer material. The metal member 40a is a member for increasing the strength of the seal member 40 and is formed of a steel material such as mild steel. The polymer member 40b contains the same material as the polymer member 30b and has the function of increasing the adhesion of the seal member 40 and the drainage performance described below.

[0040] The third cylindrical portion 41 is a cylindrical portion fixed to the inner circumferential surface 11a of the outer member 11. The third cylindrical portion 41 is fitted to the inner circumferential surface 11a with a predetermined interference. The third cylindrical portion 41 has a metal portion 41a, a polymer portion 41b that covers the radial inside of the metal portion 41a, and a polymer portion 41c that covers one end of the metal portion 41a in the axial direction. The metal portion 41a is formed from the metal member 40a, and the polymer portions 41b and 41c are formed from the polymer member 40b.

[0041] The second circular plate portion 42 is a circular plate-shaped portion extending radially inward from the other axial end of the third cylindrical portion 41. The second circular plate portion 42 has a metal portion 42a and a polymer portion 42b that covers one axial side of the metal portion 42a. The metal portion 42a is formed from the metal member 40a, and the polymer portion 42b is formed from the polymer member 40b.

[0042] The seal lip 43 is provided on the second circular plate portion 42 and is in sliding contact with the slinger 30. The seal lip 43 has a first lip 43a, a second lip 43b, and a third lip 43c. Each of the lips 43a to 43c is formed from a polymer material 40b, and extends from a radially inner end of the second circular plate portion 42 toward the slinger 30.

[0043] In this embodiment, each of the lips 43a to 43c is in contact with the slinger 30, but may face the slinger 30 with a small gap (for example, 0.5 mm or less). In addition, in this embodiment, the number of lips included in the seal lip 43 is three, but the number of lips is not particularly limited. That is, any of the lips 43a to 43c may be omitted, or a lip may be added in addition to the lips 43a to 43c.

[0044] A space formed by the seal lip 43 and the slinger 30 (for example, a space surrounded by the second lip 43b, the third lip 43c, and the first cylindrical portion 31) may be filled with a sealing liquid L1. The liquid L1 is, for example, a base oil of grease supplied to the internal space S2 to lubricate the rolling elements 13.

[0045] A space S3 and a gap S4 are formed inside the sealing device 15. The space S3 is a space surrounded by the first circular plate portion 32, the second cylindrical portion 33, the second circular plate portion 42, and the first lip 43a. The gap S4 is a gap between the outer peripheral surface 34 of the second cylindrical portion 33 and the inner peripheral surface 44 of the third cylindrical portion 41. The gap S4 includes an opening AP1 that communicates with the external space S1 on one axial side, and an opening AP2 that communicates with the space S3 on the other axial side.

[0046] 3 is an enlarged view of a portion of the sealing device 15 in FIG. 2. FIG. 3 shows an enlarged view of a region including the gap S4. The outer peripheral surface 34 of the second cylindrical portion 33 includes a first inclined surface 34a that increases in diameter toward one axial side. The first inclined surface 34a is formed of a polymer portion 33b (i.e., a hydrophobic material having a contact angle with water greater than 80 degrees). A first inclination angle θ11 of the first inclined surface 34a with respect to the axial direction is greater than 0 degrees and less than 5 degrees (0°<θ11<5°). The inner peripheral surface 35 of the second cylindrical portion 33 includes a parallel surface 35a that is parallel to the axial direction.

[0047] The inner peripheral surface 44 of the third cylindrical portion 41 includes a second inclined surface 44a whose diameter increases toward one side in the axial direction. The second inclined surface 44a is formed of a polymer portion 41b (i.e., a hydrophobic material whose contact angle with water is greater than 80 degrees). A second inclination angle θ12 of the second inclined surface 44a with respect to the axial direction is greater than 0 degrees and less than 5 degrees (0°<θ12<5°). The second inclination angle θ12 is equal to the first inclination angle θ11 (θ12=θ11). Therefore, the second inclined surface 44a faces the first inclined surface 34a in a radially parallel relationship.

[0048] The gap inclination angle θ13 in the radial direction between the first inclined surface 34a and the second inclined surface 44a with respect to the axial direction of the center line C2 is the average value of the first inclination angle θ11 and the second inclination angle θ12 (θ13 = (θ11 + θ12) / 2), and in this embodiment, these angles θ11 to θ13 are all equal (θ13 = θ12 = θ11). Therefore, the gap inclination angle θ13 is greater than 0 degrees and less than 5 degrees, and the gap S4 formed between the first inclined surface 34a and the second inclined surface 44a becomes a gap that inclines radially outward as it moves toward one axial side.

[0049] The distance H1 between the first inclined surface 34a and the second inclined surface 44a (the distance in the direction perpendicular to the center line C2, also referred to as the width of the gap S4) is, for example, 0.3 mm or more and 0.5 mm or less (0.3 mm≦H1≦0.5 mm). Furthermore, one axial end 45 of the third cylindrical portion 41 does not intersect with an imaginary line VL1 extending from the center line C2 to one axial side.

[0050] [Effects of sealing device] By setting the distance H1 to 0.5 mm or less, the sealing device 15 prevents muddy water and the like from entering from the external space S1. For example, it is possible to prevent the intrusion of sand larger than coarse sand (grain size 0.5 mm or more). On the other hand, if the distance H1 is made too narrow, foreign matter (e.g., sand) may get caught between the first inclined surface 34a and the second inclined surface 44a, damaging the sealing device 15. For this reason, the distance H1 is set to 0.3 mm or more.

[0051] With this configuration, it is difficult to completely prevent muddy water and the like from entering from the external space S1. For example, sand, silt, clay with smaller particle sizes (e.g., particle size of 0.2 mm or less) and water can enter the gap S4 from the external space S1.

[0052] Therefore, the sealing device 15 has an inclination in the gap S4. This makes it easier to discharge muddy water and the like that has once entered the gap S4 and the space S3 from the external space S1 back to the external space S1, and prevents the accumulation of muddy water and the like in the space S3, thereby suppressing deterioration of the sealing device 15. This effect will be described in detail below.

[0053] In the sealing device 15, the first inclined surface 34a and the second inclined surface 44a both increase in diameter toward one axial side, and therefore the gap S4 formed by the first inclined surface 34a and the second inclined surface 44a is a gap that inclines radially outward toward one axial side. In other words, the opening AP1 is located radially outward of the opening AP2.

[0054] Therefore, when the inner member 12 rotates relative to the outer member 11, and the slinger 30 accordingly rotates relative to the seal member 40, the centrifugal force acting on the area near the opening AP1 becomes greater than the centrifugal force acting on the area near the opening AP2, resulting in a difference in centrifugal force between the openings AP1 and AP2. This difference in centrifugal force creates a pressure difference between the openings AP1 and AP2, and a fluid flow occurs in the gap S4 from the opening AP2 toward the opening AP1.

[0055] This flow discharges muddy water and the like that has entered space S3 and gap S4 into external space S1. Furthermore, in order for muddy water and the like to enter space S3 from external space S1 while slinger 30 is rotating, the flow must go against the flow of fluid from opening AP2 toward opening AP1, thereby preventing muddy water and the like from entering space S3 from external space S1.

[0056] Furthermore, in the sealing device 15, the first inclined surface 34a and the second inclined surface 44a are both formed of a hydrophobic material (polymer material). With this configuration, muddy water and the like can slide easily on the first inclined surface 34a and the second inclined surface 44a while the slinger 30 is rotating, and the muddy water and the like can be discharged with less force (i.e., the muddy water and the like can be easily shaken off to the outside). This improves the dischargeability of muddy water and the like in the sealing device 15.

[0057] Furthermore, because the first inclined surface 34a and the second inclined surface 44a are made of a hydrophobic material, water does not easily spread over the first inclined surface 34a and the second inclined surface 44a. Therefore, while the slinger 30 is stopped, muddy water or the like can be prevented from spreading over the first inclined surface 34a and the second inclined surface 44a and entering the space S3.

[0058] In particular, the portion of first inclined surface 34a vertically above center line C1 (the portion shown in FIG. 3) is prone to dripping muddy water and the like in the direction from opening AP1 toward opening AP2 due to gravity when slinger 30 is stopped. Therefore, by forming at least first inclined surface 34a of first inclined surface 34a and second inclined surface 44a from a hydrophobic material, it is possible to prevent muddy water and the like from entering when slinger 30 is stopped.

[0059] Additionally, inner circumferential surface 35 of second cylindrical portion 33 is a parallel surface 35a that is parallel to the axial direction. That is, first inclined surface 34a increases in diameter toward one axial side, but inner circumferential surface 35 does not increase in diameter toward one axial side. During rotation of slinger 30, muddy water and the like in space S3 is collected near inner circumferential surface 35 by centrifugal force.

[0060] If the inner circumferential surface 35 were to expand in diameter toward one axial side, muddy water and the like that has collected near the inner circumferential surface 35 would be more likely to move toward the first circular plate portion 32. After the rotation of the slinger 30 stops, the muddy water and the like that has moved toward the first circular plate portion 32 would move along the first circular plate portion 32 and could potentially enter a position radially inward of the first lip 43a.

[0061] In this embodiment, the inner circumferential surface 35 is a parallel surface 35a parallel to the axial direction, and therefore no force acts to move muddy water or the like toward the first circular plate portion 32 while the slinger 30 is rotating. This further prevents muddy water or the like from entering the internal space S2. Furthermore, as described above, a fluid flow occurs from the opening AP2 toward the opening AP1 while the slinger 30 is rotating, and therefore muddy water or the like collected on the inner circumferential surface 35 is sucked into the gap S4 from the opening AP2 and is easily discharged into the external space S1.

[0062] Furthermore, one axial end 45 of the third cylindrical portion 41 does not intersect with an imaginary line VL1 extending from the center line C2 to one axial side. This configuration can prevent the flow of fluid from the opening AP2 toward the opening AP1 from being blocked by the end 45. This can increase the flow rate of the fluid, thereby improving the discharge of muddy water and the like from the sealing device 15.

[0063] [Variations] Modifications of the embodiment will be described below. In the modifications, the same components as those in the embodiment will be denoted by the same reference numerals and the description thereof will be omitted.

[0064] [Modification of the outer peripheral surface of the second cylindrical portion] 4 is an enlarged view of a portion of a sealing device 15a according to a modified example. The sealing device 15a differs from the sealing device 15 according to the above embodiment in the shape of the outer circumferential surface 34, but is otherwise the same.

[0065] The outer peripheral surface 34 of the second cylindrical portion 33 includes a first inclined surface 34b that increases in diameter toward one axial side. A first inclination angle θ21 of the first inclined surface 34b with respect to the axial direction is greater than 0 degrees and less than 5 degrees (0°<θ21<5°). Furthermore, the first inclination angle θ21 is greater than the second inclination angle θ12 of the second inclined surface 44a of the third cylindrical portion 41 (θ21>θ12). That is, the first inclined surface 34b of the modified example is inclined at a greater angle than the first inclined surface 34a of the above embodiment.

[0066] Therefore, the first inclined surface 34b and the second inclined surface 44a face each other in the radial direction so that the distance between them decreases toward one axial side. That is, the gap S4a formed between the first inclined surface 34b and the second inclined surface 44a has a shape that tapers (generally a cone shape) from the opening AP2 toward the opening AP1. The distance between the first inclined surface 34b and the second inclined surface 44a is, for example, 0.3 mm at the opening AP1 and is, for example, 0.5 mm at the opening AP2.

[0067] The gap inclination angle θ23 between the first inclined surface 34b and the second inclined surface 44a in the radial direction and the center line C3 relative to the axial direction is the average value of the first inclination angle θ21 and the second inclination angle θ12 (θ23 = (θ21 + θ12) / 2). In this modification, the second inclination angle θ12 is greater than 0 degrees, and the first inclination angle θ21 is greater than the second inclination angle θ12 (θ21 > θ12 > 0°). Therefore, the gap S4a formed between the first inclined surface 34b and the second inclined surface 44a is a gap that inclines radially outward as it approaches one axial side. An end portion 45 on one axial side of the third cylindrical portion 41 does not intersect with an imaginary line VL2 extending from the center line C3 to one axial side.

[0068] Sealing device 15a is formed with gap S4a that slopes radially outward as it approaches one axial side, so similar to the above embodiment, it is possible to generate a fluid flow from opening AP2 toward opening AP1 during rotation of slinger 30. Furthermore, in the case of sealing device 15a, opening AP1 is narrower than opening AP2, so that the fluid flow from opening AP2 toward opening AP1 can be made faster near opening AP1 during rotation of slinger 30, and muddy water or the like can be forcefully discharged from opening AP1 into external space S1.

[0069] This allows relatively heavy foreign matter (foreign matter that is difficult to move) to be more reliably discharged to the external space S1. Also, by making the flow of fluid faster near the opening AP1, it is possible to prevent relatively large foreign matter from clogging the gap S4a, and it is possible to suppress a decrease in the discharge performance of the sealing device 15a of muddy water and the like due to long-term use. Furthermore, because the opening AP1 is formed narrower, it is possible to suppress the intrusion of muddy water and the like from the opening AP1 into the gap S4a.

[0070] Furthermore, one axial end 45 of the third cylindrical portion 41 does not intersect with an imaginary line VL2 extending from the center line C3 to one axial side. This configuration can prevent the flow of fluid from the opening AP2 toward the opening AP1 from being blocked by the end 45. This can increase the flow rate of the fluid, thereby improving the discharge of muddy water and the like from the sealing device 15.

[0071] [Modification of the inner circumferential surface of the second cylindrical portion] 5 is an enlarged view of a portion of a sealing device 15b according to a modified example. The sealing device 15b differs from the sealing device 15 according to the above embodiment in the shape of the inner circumferential surface 35, but is otherwise the same.

[0072] The inner circumferential surface 35 of the second cylindrical portion 33 includes a third inclined surface 35b whose diameter decreases toward one axial side. A third inclination angle θ14 of the third inclined surface 35b with respect to the axial direction is, for example, greater than 0 degrees and less than 5 degrees (0°<θ14<5°). That is, the third inclined surface 35b is inclined toward the opposite side (the other axial side) from the first inclined surface 34a and the second inclined surface 44a.

[0073] During rotation of the slinger 30, centrifugal force causes the muddy water and other particles in the space S3 to collect near the inner circumferential surface 35. In this modified example, the inner circumferential surface 35 has a third inclined surface 35b that narrows in diameter toward one axial direction, so during rotation of the slinger 30, a force acts on the muddy water and other particles to move toward the second circular plate portion 42. Therefore, the muddy water and other particles collected near the inner circumferential surface 35 are guided along the third inclined surface 35b toward the opening AP2. As a result, the muddy water and other particles in the space S3 are more easily discharged into the external space S1.

[0074] [Other variations] The above-described sealing devices 15, 15a, 15b are provided on one axial side (vehicle inner side) of the rolling bearing device 10 (see FIG. 1). However, each of the above configurations may be applied to the sealing device 16 on the other axial side (vehicle outer side).

[0075] The above-described rolling bearing device 10 is a wheel bearing device for supporting the wheels of a vehicle such as an automobile. However, the rolling bearing device 10 may be applied to devices other than wheel bearing devices. For example, it may be applied to a rotating body bearing device for supporting a rotating body such as a propeller, a turbine, or a spinning wheel.

[0076] [Additional Note] It should be noted that at least some of the above-described embodiments and various modifications may be combined with each other in any desired manner. Furthermore, the embodiments and modifications disclosed herein are illustrative in all respects and are not limiting. The scope of the present disclosure is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0077] 10. Rolling bearing device 11 Outer member 11a Inner surface 11b1 Outer raceway 11b2 Outer ring raceway 12 Inner member 12a Outer surface 12b1 Inner raceway 12b2 Inner raceway 13 Rolling elements 14 Cage 15 Sealing device 15a Sealing device 15b Sealing device 16 Sealing device 21 Hub axle 21a flange 22 Inner Circle 30 Slinger 30a Metallic parts 30b Polymer material 31 First cylindrical section 32 First disc section 32a Metal parts 32b Polymer part 33 Second cylindrical section 33a Metal parts 33b Polymer part 33c Polymer part 34 Outer surface 34a 1st slope 34b 1st slope 35 Inner surface 35a parallel plane 35b Third slope 40 sealing material 40a Metallic parts 40b Polymeric material 41 Third cylindrical section 41a Metal parts 41b Polymer part 41c Polymer part 42 Second disc section 42a Metal parts 42b Polymer part 43 Seal lip 43a First Lip 43b 2nd lip 43c 3rd lip 44 Inner surface 44a 2nd slope 45 End 90 Sealing device 91 Slinger 91a Slinger fitting part 91b Standing board section 91c Cylindrical part 92 Seal plate 92a Seal plate fitting part 92b Lip support 92c axial lip 92d radial lip 92e Grease Lip 93 Outer surface 94 Inner peripheral surface 95 Inner member 96 Outer member C1 center line C2 center line C3 center line VL1 Virtual Line VL2 Virtual Line S1 External space S2 interior space S3 space S4 Gap S4a Gap S91 External space S92 interior space S93 Space L1 liquid AP1 aperture AP2 aperture θ11 1st inclination angle θ12 2nd inclination angle θ13 Gap inclination angle θ14 3rd inclination angle θ21 1st inclination angle θ23 Gap inclination angle H1 distance

Claims

1. A sealing device provided between an outer member having an outer ring raceway on an inner peripheral surface and an inner member having an inner ring raceway on an outer peripheral surface and rotating relative to the outer member, a slinger having a first cylindrical portion fixed to an outer peripheral surface of the inner member, a first circular plate portion extending radially outward from one axial end of the first cylindrical portion, and a second cylindrical portion extending radially outward from the radially outer end of the first circular plate portion; a seal member including a third cylindrical portion fixed to an inner peripheral surface of the outer member, a second circular plate portion extending radially inward from the other axial end of the third cylindrical portion, and a seal lip provided on the second circular plate portion and in sliding contact with the slinger; Equipped with the second cylindrical portion has a metal portion and a polymer portion covering the radially outer side of the metal portion, an outer circumferential surface of the polymer portion includes a first inclined surface that increases in diameter toward one axial side, the first inclined surface being formed of a polymer material; an inner circumferential surface of the third cylindrical portion includes a second inclined surface that faces the first inclined surface in the radial direction and increases in diameter toward one axial side; an inner circumferential surface of the third cylindrical portion includes a cylindrical inner circumferential surface located on the other axial side of the second inclined surface, the outer peripheral surface of the second cylindrical portion has a chamfered portion that is located radially inward of the cylindrical inner peripheral surface and that decreases in diameter toward the other axial side, an end of the second inclined surface on the other axial side is located radially outward of an end of the first inclined surface on the other axial side; Sealing device.

2. The inner circumferential surface of the second cylindrical portion includes a parallel surface parallel to the axial direction or a third inclined surface whose diameter decreases toward one side in the axial direction. The sealing device according to claim 1 .

3. a first inclination angle of the first inclined surface with respect to the axial direction is larger than a second inclination angle of the second inclined surface with respect to the axial direction; The sealing device according to claim 1 or 2.

4. an end portion on one axial side of the third cylindrical portion does not intersect with an imaginary line extending to one axial side through a center line between the first inclined surface and the second inclined surface; The sealing device according to any one of claims 1 to 3.

5. the outer member; The inner member; a plurality of rolling elements provided between the outer ring raceway and the inner ring raceway; The sealing device according to any one of claims 1 to 4; A rolling bearing device comprising:

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