Sealing device

Abstract

The sealing device includes a body, a first lip protruding from the body, a second lip protruding from the body and positioned to be spaced apart from the first lip portion in a radially inward direction of the first lip, a first grease applied to a surface of the first lip, and a second grease applied to a surface of the second lip. And the second lubricating grease is coated on the surface of the second lip part. Characteristics of the first grease are different from those of the second grease.

Description

Technical Field

[0001] The present invention relates to sealing devices. Background Art

[0002] A ball bearing is used in a wheel hub of a vehicle. The interior of the ball bearing is sealed by using a sealing device, an example of which is disclosed in Patent Document 1.

[0003] The sealing device disclosed in Patent Document 1 is press-fitted between the inner ring and the outer ring of the bearing and is provided with a lip portion. The distal end surface of each lip portion is provided to elastically slide in contact with the inner peripheral surface of the inner ring of the bearing, which prevents the intrusion of foreign matter such as muddy water or dust. Grease is applied to the distal end surface of each lip portion to promote sliding properties, etc.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-185491 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] In the conventional sealing device, the same grease is applied to each lip of the sealing device. Therefore, the optimal performance of the lips of the conventional sealing device cannot be achieved. Therefore, the conventional sealing device cannot achieve the full functional performance of the conventional sealing device of inhibiting the entry of foreign matter and low torque.

[0009] Solutions for solving problems

[0010] In order to solve the above-mentioned problems, a sealing device according to one aspect of the present disclosure is a sealing device for sealing an annular gap between an inner member and an outer member of a hub bearing, wherein the inner member is rotatable relative to the outer member. The sealing device includes a main body, a first lip, a second lip, a first grease, and a second grease, wherein the first lip protrudes from the main body, the second lip protrudes from the main body and is positioned to be separated from the first lip in a radially inward direction of the first lip, the first grease is applied to the surface of the first lip, and the second grease is applied to the surface of the second lip. The first lip and the second lip each extend from the main body toward the inner member or the outer member, and the properties of the first grease are different from those of the second grease.

[0011] Effects of the Invention

[0012] According to the present disclosure, the functional characteristics of the sealing device can be fully realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] [ Figure 1] is a cross-sectional view of the hub bearing according to the first embodiment.

[0014] [ Figure 2 ] is a partial cross-sectional view of a sealing member, which is an example of a sealing device in use.

[0015] [ Figure 3 ] shows the state in which the hub bearing is not installed Figure 2 The sealing member shown.

[0016] [ Figure 4 ] shows two or more sealing members in a stacked state.

[0017] [ Figure 5 ] shows the relationship between the consistency of the first grease and the torque.

[0018] [ Figure 6 ] shows the relationship between the consistency of the second grease and the torque.

[0019] [ Figure 7 ] is an illustration of the process for measuring consistency.

[0020] [ Figure 8 ] is an illustration of the process for measuring consistency.

[0021] [ Fig. 9 ] shows the relationship between mud and water resistance, torque and grease.

[0022] [ Fig.10 ] is a diagram showing a sealing member according to a first modification.

[0023] [ Fig.11 ] is a diagram showing a sealing member according to a second modification. DETAILED DESCRIPTION

[0024] A description of preferred embodiments of the present disclosure will now be given below with reference to the accompanying drawings. In the accompanying drawings, the sizes and proportions of the various components may be different from the actual sizes and proportions, and some components are schematically described for ease of understanding. The scope of the present disclosure is not limited to these embodiments unless otherwise explicitly stated in part of the present disclosure.

[0025] 1. First Embodiment

[0026] 1-1. Hub bearing

[0027] Figure 1 is a partial cross-sectional view of the hub bearing 100 according to the first embodiment. Hereinafter, the upward direction from any point in the figure is referred to as the "X1 direction", and the downward direction from any point in the figure is referred to as the "X2 direction". In addition, the application of the present disclosure is not limited to Figure 1 The hub bearing 100 shown is a ball bearing, but the application of the present disclosure is not limited to ball bearings. The hub bearing 100 may be another type of bearing, such as a roller bearing or a needle bearing. Figure 1 The hub bearing 100 shown is used for a vehicle, but the hub bearing according to the present disclosure can also be applied to machines other than vehicles.

[0028] Figure 1 The hub bearing 100 shown includes a hub 11, an inner ring 12, an outer ring 13, a plurality of balls 141, a plurality of balls 142, a plurality of retainers 151, and a plurality of retainers 152. The hub 11 is an example of an "inner member". The outer ring 13 is an example of an "outer member". Here, Figure 1 Any one of the plurality of balls 141 and any one of the plurality of balls 142 are shown. Figure 1 Any one of the plurality of retainers 151 and any one of the plurality of retainers 152 are shown.

[0029] The hub 11 has an opening HX through which a main shaft (not shown) is inserted. The center axis of the opening HX corresponds to the center axis AX of the hub bearing 100. The center axis AX extends in the direction X1. The wheels of the vehicle are arranged on the outside of the vehicle in the direction X1 of the hub bearing 100. The differential and similar components are arranged toward the inside of the vehicle in the direction X2 of the hub bearing 100. Figure 1 The leftward direction in is the radially outward direction, Figure 1 The rightward direction in FIG. 1 is the radially inward direction. The hub 11 further comprises a flange 110 which extends radially outward more than the outer ring 13. The wheel can be attached to the flange 110 by using bolts 19.

[0030] The inner ring 12 is attached to the hub 11. The outer ring 13 is positioned radially outwardly more than the inner ring 12, and the outer ring is spaced apart from the inner ring 12 and the hub 11. The outer ring 13 includes a base 131 and an end 132 extending from the base 131 in a direction X1. The balls 141 are arranged between the hub 11 and the outer ring 13. Although not shown in detail, the balls 141 are arranged circumferentially in a row around the center axis AX. The balls 142 are positioned relative to the balls 141 in the X1 direction. The balls 141 are arranged between the inner ring 12 and the outer ring 13. The balls 141 are arranged circumferentially in a row around the center axis AX. Similarly, the balls 142 are arranged between the inner ring 12 and the outer ring 13. The balls 142 are arranged circumferentially in a row around the center axis AX. The retainer 151 retains the balls 141. The retainer 152 retains the balls 142 .

[0031] In the hub bearing 100, the outer ring 13 is fixed to the knuckle 16, and the hub 11 and the inner ring 12 rotate relative to the outer ring 13. The interior of the hub bearing 100 is filled with lubricant.

[0032] like Figure 1 As shown, the sealing member 2 is arranged between the hub 11 and the outer ring 13. The sealing member 2 corresponds to the "sealing member". The sealing member 2 is annular, and the sealing member seals the gap between the hub 11 and the outer ring 13. The sealing member 4 is arranged between the inner ring 12 and the outer ring 13. The sealing member 4 is annular, and the sealing member seals the gap between the inner ring 12 and the outer ring 13. The sealing member 4 is positioned closer to the inside of the vehicle than the sealing member 2. The sealing member 2 is positioned closer to the outside of the vehicle than the sealing member 4. The arrangement of the sealing members 2 and 4 enables the hub 11 and the inner ring 12 to rotate while preventing foreign matter (such as muddy water and dust) from entering the interior of the hub bearing 100.

[0033] 1-2. Sealing member 2

[0034] The sealing member 2 is fixed to the outer ring 13 , and slides against the inner peripheral surface 111 of the hub 11 .

[0035] Figure 2 2 is a partial cross-sectional view of a sealing member 2, which is an example of a sealing device when in use. The phrase "when in use" refers to a state in which the sealing member 2 is attached to the hub bearing 100. Figure 2 As shown, the sealing member 2 is a composite material structure including an elastic ring 20 and a reinforcement ring 25. The elastic ring 20 is formed of an elastomer, for example. The reinforcement ring 25 is formed of a metal or an alloy. The reinforcement ring 25 is rigid enough to reinforce the elastic ring 20. The reinforcement ring 25 is in close contact with the elastic ring 20, and the reinforcement ring is partially embedded in the elastic ring 20.

[0036] The sealing member 2 includes a main body 3, a first lip 41, a second lip 42, a third lip 43, and a fourth lip 44. The main body 3 is fixed to the outer ring 13. The first lip 41, the second lip 42, the third lip 43, and the fourth lip 44 protrude from the main body 3 toward the hub 11. The hub 11 is an example of an "inner member".

[0037] exist Figure 2 In the example shown, the body 3 includes a cylindrical portion 31, an outer annular portion 32, and an inner annular portion 33. The cylindrical portion 31 includes a thick portion of the elastic ring 20 and a U-shaped (cross-sectional) portion of the reinforcing ring 25. The cylindrical portion 31 is disposed outside the end portion 132 of the outer ring 13, and the cylindrical portion is centered on the central axis AX. The cylindrical portion 31 is fixedly fitted into the end portion 132.

[0038] The outer annular portion 32 extends radially outward from the cylindrical portion 31. The outer annular portion 32 is constituted by the elastic ring 20 and a part of the reinforcement ring 25.

[0039] The inner annular portion 33 extends radially inward from the cylindrical portion 31. Figure 2 In the example shown, the inner annular portion 33 extends radially inwardly from the cylindrical portion 31 along the direction X1 at an inclined angle, and then the inner annular portion extends radially inwardly further. The inner annular portion 33 is composed of the elastic ring 20 and a portion of the reinforcement ring 25. A portion of the reinforcement ring 25 included in the inner annular portion 33 contacts the end 132.

[0040] Figure 2 Each of the first lip 41, the second lip 42, the third lip 43, and the fourth lip 44 shown in the figure is elastic and includes a part of the elastic ring 20. The first lip 41, the second lip 42, the third lip 43, and the fourth lip 44 are spaced apart from each other. Each of the first lip 41, the second lip 42, the third lip 43, and the fourth lip 44 is thinly annular and protrudes from the body 3 toward the hub 11. When the sealing member 2 is arranged on the hub bearing 100, the first lip 41, the second lip 42, the third lip 43, and the fourth lip 44 are in contact with the hub 11, and the first lip, the second lip, the third lip, and the fourth lip are deformed under the reaction force. In use, the distal end of each of the first lip 41 , the second lip 42 and the third lip 43 contacts and slides on the inner peripheral surface 111 of the hub 11 .

[0041] The first lip 41 is arranged radially outwardly more than the second lip 42. The first lip 41 is called a side lip. The first lip 41 extends from the inner annular portion 33 of the body 3 in the direction X1, that is, the first lip extends toward the outside of the vehicle. The first lip 41 prevents foreign matter such as muddy water from entering the inside of the hub bearing 100.

[0042] The second lip 42 is provided separately from the first lip 41 in the radially inward direction of the first lip 41. The second lip 42 is an intermediate lip between the first lip 41 and the third lip 43. The second lip 42 extends from the inner annular portion 33 of the body 3 in the X1 direction, that is, the second lip extends toward the outside of the vehicle. Similar to the first lip, the second lip 42 prevents foreign matter such as muddy water from entering the inside of the hub bearing 100. More specifically, the second lip 42 blocks foreign matter that has moved past the first lip 41.

[0043] The third lip 43 is positioned radially innermost among the lips. The third lip 43 is also called a grease lip. The third lip 43 extends radially inward from the inner annular portion 33 of the body 3, and the third lip further extends at an inclined angle along the direction X2. The third lip 43 prevents the grease from moving out from the inner side of the hub bearing 100.

[0044] The fourth lip 44 is positioned at the radially outermost side of the lip. The fourth lip 44 is positioned radially outwardly more than the first lip 41, and the fourth lip is also referred to as an outer lip. The fourth lip 44 extends from the outer annular portion 32 of the body 3 in the direction X1, that is, the fourth lip extends toward the outside of the vehicle. The fourth lip 44 prevents foreign matter such as muddy water from entering the inner side of the hub bearing 100. The provision of the fourth lip 44 enhances the prevention of foreign matter from entering. However, the fourth lip 44 may be appropriately omitted. In addition, the fourth lip 44 contacts the flange 110. However, the fourth lip 44 does not need to contact the flange 110, and there may be a gap between the fourth lip 44 and the flange 110. That is, the fourth lip 44 may be used as a labyrinth seal.

[0045] Figure 3 The hub bearing 100 is shown in a state where it has not yet been installed on the hub bearing 100. Figure 2 The sealing member 2 shown. Figure 3 As shown, before the sealing member 2 is installed on the hub bearing 100, no force acts on any of the first lip 41, the second lip 42, the third lip 43 and the fourth lip 44, so the first lip, the second lip, the third lip and the fourth lip will not be deformed and remain straight.

[0046] 1-3. Grease

[0047] like Figure 3 As shown, grease is applied to each of the first lip 41, the second lip 42, and the third lip 43. Grease may also be appropriately applied to the fourth lip 44. However, when the fourth lip 44 is used for a labyrinth seal, grease is not applied to the fourth lip. Applying grease to each lip enhances the sealing performance, sliding properties, and durability of the lip compared to when no grease is applied.

[0048] The first lip 41 has a surface coated with the first grease G1. The second lip 42 and the third lip 43 each have a surface coated with the second grease G2 different from the first grease G1. The first grease G1 is applied to the surface of the first lip 41, in particular, to the distal surface of the first lip. More specifically, the first grease G1 is applied to the radial inner surface of the distal surface of the first lip 41. The second grease G2 is applied to the surface of the second lip 42, in particular, to the distal surface. In addition, the second grease G2 is applied to the surface of the third lip 43, in particular, to the distal surface. More specifically, the second grease G2 is applied to the radial inner surface of the distal surface of the second lip 42 and the radial inner surface of the distal surface of the third lip 43. The first grease G1 and the second grease G2 each include a base oil, a thickener, and an additive.

[0049] Figure 4 Two or more sealing members 2 are shown in a stacked state. Figure 4 When stacked as shown, these sealing members can be packed at the factory for transportation to the destination. After grease is applied to the three lips of each sealing member 2, the sealing members 2 are stacked. Therefore, each of the first grease G1 and the second grease G2 is applied before packaging and transportation.

[0050] The properties of the grease applied to the first lip 41 and the grease applied to the second lip 42 are different. By applying greases of different properties to the first lip 41 and the second lip 42, the best performance of the lips can be achieved. Therefore, the best and reliable performance of the sealing member 2 can be achieved.

[0051] In this embodiment, an example of the characteristics of each of the first grease G1 and the second grease G2 is expressed as a consistency value specified in JIS K2220:2013. Another example of the characteristics is the shear viscosity of the grease in the sliding state. Specifically, the consistency value of the second grease G2 specified in JIS K2220:2013 is different from the consistency value of the first grease G1 specified in JIS K2220:2013. In addition, the shear viscosity of the second grease G2 in the sliding state is different from the shear viscosity of the first grease G1 in the sliding state. The difference in the consistency value or shear viscosity between the first grease G1 and the second grease G2 can prevent the entry of foreign matter and achieve low torque. The relationship between the consistency value and the shear viscosity holds when the first grease G1 and the second grease G2 each have the same base oil viscosity, the same type of base oil, and the same type of thickener.

[0052] The content percentage of the thickener in the second grease G2 is different from the content percentage of the thickener in the first grease G1, so the consistency value of the second grease G2 is different from the consistency value of the first grease G1. In addition, the shear viscosity of the second grease G2 is different from the shear viscosity of the first grease G1. Therefore, prevention of foreign matter entry and low torque can be achieved. When the first grease G1 and the second grease G2 have the same type of thickener, the relationship between the content percentages of the thickeners holds.

[0053] In this embodiment, the viscosity value of the second grease G2 is lower than that of the first grease G1. Thus, for each of the first lip 41 and the second lip 42, low torque can be achieved. In addition, it is easy to prevent foreign matter from moving inside the first grease G1, thereby preventing the foreign matter from reaching the second lip 42. The shear viscosity of the second grease G2 is lower than that of the first grease G1. Thus, similar to the effect provided when the viscosity value of the second grease G2 is lower than that of the first grease G1, foreign matter can be prevented from reaching the second lip 42 and low torque can be achieved. As described above, when the first grease G1 and the second grease G2 each have the same base oil viscosity, the same type of base oil, and the same type of thickener, the relationship between the viscosity value and the shear viscosity holds.

[0054] The content percentage of the thickener in the second grease G2 is less than the content percentage of the thickener in the first grease G1. Therefore, the consistency value of the second grease G2 can be reduced to be less than the consistency value of the first grease G1. In addition, the shear viscosity of the second grease G2 can be reduced to be less than the shear viscosity of the first grease G1. For these reasons, the above-mentioned effect is shown. When the first grease G1 and the second grease G2 have the same type of thickener, the relationship between the content percentages of the thickeners holds.

[0055] The first lip 41 is more directly and therefore more easily exposed to foreign matter such as muddy water from the outside than the second lip 42. For this reason, the first lip 41 requires high sealing performance to prevent the entry of foreign matter. However, the high sealing performance causes the first lip 41 to generate a high surface pressure on the inner peripheral surface 111 of the hub 11, which leads to premature wear of the first lip 41 and a shortened life of the first lip 41. In particular, if the fourth lip 44 is not provided or if the fourth lip 44 is a labyrinth seal, the first lip 41 is more directly and easily exposed to the outside. In this case, air or other gas flows out from the space between the first lip 41 and the second lip 42, and negative pressure may be generated. When the negative pressure is immediately eliminated, the torque increases, and thus torque interference may be generated. Thus, the first lip 41 needs to operate with low friction in addition to having sealing performance to prevent wear and prevent airflow to avoid the generation of negative pressure.

[0056] As described above, the first grease G1 applied to the first lip 41 has a lower consistency than the second grease G2 applied to the second lip 42. That is, the first grease G1 is harder than the second grease G2. High consistency achieves low wear and low torque. However, using the first grease G1 with low consistency for the first lip 41 may cause a channeling effect due to shearing during use of the sealing member 2. The channeling effect here refers to a phenomenon in which the first grease G1 is pushed away from the first lip 41.

[0057] When the channel effect shears the first grease G1 between the first lip 41 and the inner peripheral surface 111, the first lip 41 is not easily subjected to resistance of the first grease G1. As a result, the viscous resistance is reduced, making it easy to generate a gap between the first lip 41 and the inner peripheral surface 111. The reduction in viscous resistance results in low torque, thereby providing wear resistance. The generation of the gap also enables the generation of airflow.

[0058] Figure 5 The relationship between the consistency of the first grease G1 and the torque is shown. Figure 5 The first grease G1 used in the present invention has the same base oil viscosity, the same type of base oil and the same type of thickener. Figure 5 As shown, as the consistency of the first grease G1 decreases, the torque decreases. That is, the softer the first grease G1 is, the lower the torque is. This may be related to the ease of channeling. Therefore, it is preferred that the grease used as the first grease G1 is a grease that easily produces channeling.

[0059] Since the first grease G1 has a lower consistency than the second grease G2, it is easy to prevent foreign matter from moving in the first grease G1. Thus, foreign matter is prevented from reaching the second lip portion 42, which enhances the sealing performance of the first lip portion 41.

[0060] The first lubricating grease G1 is described from the perspective of consistency. The effect provided by the shear viscosity of the first lubricating grease G1 is also the same as the effect provided by the above-mentioned consistency.

[0061] As described above, the second lip 42 is less exposed to the outside than the first lip 41 and does not need to ensure the impact airflow. However, low friction is required to prevent wear. Sealing performance is also required to block fine foreign matter passing through the first lip 41.

[0062] As described above, the second grease G2 applied to the second lip 42 has a higher consistency than the first grease G1 applied to the first lip 41. High consistency leads to low torque and low wear. Thus, using the second grease G2 enhances sealing performance and low torque compared to not using grease.

[0063] Figure 6 The relationship between the consistency of the second grease G2 and the torque is shown. Figure 6 The second grease G2 used in the present invention has the same base oil viscosity, the same type of base oil and the same type of thickener. Figure 6 As shown, as the consistency of the second grease G2 increases, the torque decreases. Low torque is achieved by reducing the shear viscosity or consistency value of the second grease G2 to a value less than the shear viscosity or consistency value of the first grease G1. Therefore, it is preferred that the grease used as the second grease G2 is a grease that is less likely to produce a channeling effect.

[0064] The second lubricating grease G2 is described from the perspective of its consistency. The effect provided by the hardness (ie, viscosity) of the second lubricating grease G2 is also the same as the effect provided by the above-mentioned consistency.

[0065] As described above, using the first grease G1 for the first lip 41 and using the second grease G2 for the first lip 41 provides better performance of the first lip 41 and the second lip 42 than when the grease is not selectively used. Specifically, for the first grease G1, a grease that easily causes a channeling effect is selected, and for the second grease G2, a grease with a low grease viscosity or a low consistency value is selected. This selection achieves a low torque of the sealing member 2.

[0066] The third grease G3, which is the same as the second grease G2, applied to the third lip 43 provides the same effect as that of the second lip 42 for the third lip 43. In other words, the use of the third grease G3 enhances the sealing performance and provides low torque. By enhancing the sealing performance of the third lip 43, it is possible to prevent the lubricant from moving from the inside to the outside. Another grease different from the second grease G2 may also be applied to the third lip 43.

[0067] Figure 7 and Figure 8 are explanatory diagrams each showing a process for measuring the consistency. The consistency is measured according to the process specified in ISK2220:2013. A brief description of the process for measuring the consistency of the first grease G1 will be given below. The same process applies to the measurement of the consistency of the second grease G2.

[0068] like Figure 7 As shown, the first grease G1 is placed in the mixer 90 specified in JIS K2220: 2013. After the first grease G1 is maintained at a predetermined temperature, the predetermined taper 91 is adjusted so that the tip of the taper 91 contacts the upper surface of the first grease G1. Then, as Figure 8 As shown, the cone 91 was allowed to penetrate the first grease G1 for 5±0.1 seconds, and the penetration depth was measured. This measurement was performed three times. The consistency was obtained by multiplying the penetration depth by 10.

[0069] The consistency value of the first grease G1 is preferably No. 3 or No. 4, but is not particularly limited thereto. The consistency value of the second grease G2 is preferably No. 1 or No. 2, but is not particularly limited thereto. The consistency of the first grease G1 is preferably 175 or more and 250 or less, but is particularly limited thereto. The consistency of the second grease G2 is 265 or more and 340 or less, but is particularly limited thereto. Such a consistency number or consistency makes it easier to obtain a channeling effect through the first lip 41, and makes it more difficult to obtain a channeling effect through the second lip 42. As a result, an effective effect can be provided by the first lip 41 and the second lip 42.

[0070] It is preferred that the first grease G1 and the second grease G2 each have the same type of base oil, the same type of thickener and the same type of additives. By using these same types, the desired hardness or consistency can be easily adjusted. Specifically, for example, adjusting the content percentage of the grease or changing the dispersion conditions of the grease can easily adjust the hardness or consistency of the grease. Therefore, even if the content percentage of the thickener is the same, the consistency can be changed. In this case, the conditions for homogenizing the grease are consistent. The base oil can be a mineral oil or a synthetic oil, preferably a synthetic hydrocarbon oil, but is not particularly limited thereto. The thickener can be a metal soap, a metal complex soap or a urea compound, but is not particularly limited thereto. The thickener is preferably a lithium soap or a lithium complex soap.

[0071] The ten-point average roughness (RzJIS) of the sliding surface of the first lip 41 is preferably 5 μm or more and 20 μm or less, but not particularly limited thereto. The ten-point average roughness (RzJIS) of the sliding surface of the second lip 42 is preferably 5 μm or less, but not particularly limited thereto. Within this range, the sealing performance and low torque of the sealing member 2 are particularly enhanced.

[0072] Fig. 9 The relationship between muddy water resistance, torque and grease is shown. Fig. 9 The muddy and water resistance shown is evaluated in terms of the time [h] during which the sealing performance is ensured in muddy and water conditions. Fig. 9In the illustrated reference example 1, the ten-point average roughness of the first lip 41x and the ten-point average roughness of the second lip 42x are each 10 μm or more and 20 μm or less. The consistency value of the first grease G1x and the consistency value of the second grease G2x are each No. 2. In reference example 2, the ten-point average roughness of the first lip 41x is 10 μm or more and 20 μm or less. The ten-point average roughness of the second lip 42x is 1 μm or more and 5 μm or less. The consistency value of the first grease G1 and the consistency value of the second grease G2 are each No. 2. In this embodiment, the ten-point average roughness of the first lip 41 is 10 μm or more and 20 μm or less. The ten-point average roughness of the second lip 42 is 1 μm or more and 5 μm or less. The first lubricating grease G1 has a consistency of No. 3 or No. 4. The second lubricating grease G2 has a consistency of No. 1.

[0073] like Fig. 9 As shown, in this embodiment, the time [h] for ensuring the sealing performance under muddy water conditions is long, and the torque [N·cm] is smaller than that in Reference Examples 1 and 2. Therefore, the consistency value of the second grease G2 is smaller than that of the first grease G1, which achieves the sealing performance and low torque of the sealing member 2. In addition, the ten-point average roughness of the first lip 41 is greater than the ten-point average roughness of the second lip 42, which more effectively enhances the sealing performance and low torque of the sealing member 2.

[0074] 2. Second Embodiment

[0075] Hereinafter, a description will be given of a second embodiment according to the present disclosure. In the following exemplary embodiments, a detailed description of each element having the same function or effect as that of the first embodiment will be appropriately omitted.

[0076] In the second embodiment, the viscosity value of the second grease G2 is greater than the viscosity value of the first grease G1. In addition, in the second embodiment, the second grease G2 is harder than the first grease G1. Therefore, it is possible to reduce the risk that the second grease G2 may leak to the outside. For example, when centrifugal force acts on the second grease G2, the risk of the second grease G2 falling off the second lip 42 and leaking to the outside is reduced. Therefore, the second grease G2 is retained on the second lip 42, thereby effectively showing the performance of the second lip 42 in preventing foreign matter from flowing through the first lip 41. The relationship between the viscosity value and the hardness holds true when the first grease G1 and the second grease G2 have the same base oil viscosity, the same type of base oil, and the same type of thickener.

[0077] The content percentage of the thickener in the second grease G2 is greater than the content percentage of the thickener in the first grease G1. Therefore, the consistency value of the second grease G2 can be increased to be higher than the consistency value of the first grease G1. In addition, the hardness of the first grease G1 can be increased to be higher than the hardness of the second grease G2. As a result, the above-mentioned effects are achieved. When the first grease G1 and the second grease G2 have the same type of thickener, the relationship of the content percentage of the thickener holds.

[0078] 3. Third embodiment

[0079] Hereinafter, a description will be given of a third embodiment according to the present disclosure. In the following exemplary embodiments, a detailed description of each element having the same function or effect as that of the first embodiment will be appropriately omitted.

[0080] In this embodiment, an example of the characteristic of each of the first grease G1 and the second grease G2 is water resistance. Specifically, the water resistance of the first grease G1 is greater than the water resistance of the second grease G2. Since the first lip 41 is closer to the outside than the second lip 42, foreign matter such as muddy water easily enters. The first grease G1 having water resistance improves the life of the entire sealing member 2.

[0081] 4. Fourth embodiment

[0082] Hereinafter, a description will be given of a fourth embodiment according to the present disclosure. In the following exemplary embodiments, a detailed description of each element having the same function or effect as that of the first embodiment will be appropriately omitted.

[0083] In this embodiment, an example of the characteristic of each of the first grease G1 and the second grease G2 is color density. Specifically, the color density of the first grease G1 is greater than the color density of the second grease G2. Color density is expressed as brightness or saturation. The lower the brightness or saturation, the darker the color. The first grease G1 is positioned closer to the outside than the second grease G2. Since the color of the first grease G1 is darker, leakage of the first grease G1 caused by water or the like is easily recognized, and leakage of the first grease G1 is easily analyzed.

[0084] 5. Modifications

[0085] Various modifications described below can be derived from the foregoing embodiments. Various modifications can be appropriately combined.

[0086] 5-1. First Amendment

[0087] Fig.102A according to the first modification. In the foregoing embodiment, the sealing member 2 disposed near the vehicle exterior is described as an example of a "sealing device" according to the present disclosure. The present disclosure may be applied to a sealing member disposed toward the vehicle interior.

[0088] Fig.10 The sealing member 2A shown is an example of a "sealing device". The sealing member 2A is arranged at Figure 1 The sealing member 4 shown corresponds to the position. The sealing member 2A is a sealing device arranged to face the interior of the vehicle.

[0089] The sealing member 2A is a composite material structure including an elastic ring 20A and a reinforcement ring 25A. The reinforcement ring 25A is embedded in the elastic ring 20A and is fixed to the outer ring 13. The outer ring 13 is another example of an "external member". The sealing member 2A includes a main body 3A, a first lip 41A, a second lip 42A, and a third lip 43A. The first lip 41A, the second lip 42A, and the third lip 43A protrude from the main body 3A toward the hanging ring 17 fixed to the inner ring 12. The hanging ring 17 is another example of an "internal member". The hanging ring 17 includes an annular portion 171 and a flange 172, which extends from the annular portion 171 toward the outer ring 13. The magnetic rubber 18 for detecting the rotation speed of the inner ring 12 is fixed to the flange 172.

[0090] The main body 3A is fixed to the outer ring 13, and the main body includes a part of the elastic ring 20A and the reinforcing ring 25A. The first lip 41A, the second lip 42A, and the third lip 43A are each a part of the elastic ring 20A. The distal end of each of the first lip 41A, the second lip 42A, and the third lip 43A contacts the inner peripheral surface 170 of the lifting ring 17, and the distal end of each of the first lip, the second lip, and the third lip slides on the inner peripheral surface 170 when in use.

[0091] The first lip 41A is positioned radially outwardly more than the second lip 42. The first lip 41A is called a side lip. The first lip 41A extends toward the flange 172 of the lifting ring 17 and contacts the flange 172. The second lip 42A is an intermediate lip between the first lip 41A and the third lip 43A. The second lip 42A extends toward the annular portion 171 of the lifting ring 17 and contacts the annular portion 171. The third lip 43A is positioned radially innermost among the lips. The third lip 43A is called a grease slider. The third lip 43A extends toward the annular portion 171 of the lifting ring 17 and contacts the annular portion 171.

[0092] The first grease G1 is applied to the surface of the first lip 41A, especially to the distal end surface of the first lip. The second grease G2 is applied to the surface of each of the second lip 42A and the third lip 43A, especially to the distal end surface of each of the second lip and the third lip. Another grease different from the second grease G2 may also be applied to the third lip 43A.

[0093] The first grease G1 is applied to the first lip 41A. The second grease G2 having properties different from those of the first grease G1 is applied to each of the second lip 42A and the third lip 43A. Thus, the sealing member 2A provides effects similar to those of the embodiments.

[0094] 5-2. Second Amendment

[0095] Fig.11 is a diagram of a seal member 2B according to a second modification. In the aforementioned embodiment, the seal member 2 is fixed to the outer ring 13, which is an example of an “external member.” However, in the present disclosure, the seal member 2B may be fixed to an “internal member.”

[0096] Fig.11 The illustrated seal member 2B is fixed to the hub 11. The hub 11 is another example of an "inner member". The annular seal cover 6 is fixed to the outer ring 13. In this modification, the structure 60B including the seal cover 6 and the seal member 2B is another example of a "sealing device".

[0097] The sealing cover 6 is formed of, for example, metal or alloy. The sealing cover 6 includes a fixing portion 61, an outer annular portion 62, and an inner annular portion 63. The fixing portion 61 is fixed to the outer ring 13. The outer annular portion 62 extends radially outward from the fixing portion 61, and the outer annular portion extends at an inclined angle along the direction X1. The inner annular portion 63 is opposite to the outer annular portion 62, and the inner annular portion is connected to the fixing portion 61. The inner annular portion 63 extends radially inward from the fixing portion 61, and then the inner annular portion extends along the direction X1.

[0098] Sealing member 2B is a composite material structure including an elastic ring 20B and a reinforcing ring 25B. The reinforcing ring 25B is embedded in the elastic ring 20B and is fixed to the hub 11. The hub 11 is another example of an "internal member". Sealing member 2B includes a main body 3B, a first lip 41B, a second lip 42B and a third lip 43B. The first lip 41B, the second lip 42B and the third lip 43B each protrude from the main body 3B toward the outer ring 13. The outer ring 13 is another example of an "external member". The distal end of each of the first lip 41B, the second lip 42B and the third lip 43B contacts the outer surface of the sealing cover 6, and the distal end of each of the first lip, the second lip and the third lip slides on the outer surface of the sealing cover when in use.

[0099] The body 3B is fixed to the hub 11, and includes the elastic ring 20B and a part of the reinforcing ring 25B. The first lip 41B, the second lip 42B, and the third lip 43B are each a part of the elastic ring 20B.

[0100] The first lip 41B is arranged radially outwardly more than the second lip 42. The first lip 41B is called a side lip. The second lip 42B is an intermediate lip between the first lip 41B and the third lip 43B. The third lip 43B is positioned radially most inward among the lips. The third lip 43B is called a grease slider.

[0101] The first grease G1 is applied to the surface of the first lip 41B, especially to the distal end surface of the first lip. The second grease G2 is applied to the surface of each of the second lip 42B and the third lip 43B, especially to the distal end surface of each of the second lip and the third lip. Another grease different from the second grease G2 may also be applied to the third lip 43B.

[0102] The first grease G1 is applied to the first lip 41B. The second grease G2 having properties different from those of the first grease G1 is applied to each of the second lip 42B and the third lip 43B. Thus, the sealing member 2B provides effects similar to those of the embodiments.

[0103] 5-3. Other changes

[0104] The structure of the "sealing device" may be a structure other than the structures described in the first embodiment, the first modification, and the second modification. For example, in the first embodiment, the sealing member 2 includes the fourth lip 44; however, the fourth lip 44 may be omitted. For example, the cylindrical portion 31 of the body 3 included in the sealing member 2 is positioned radially outwardly than the end 132 of the outer ring 13. However, the cylindrical portion 31 may be positioned radially inwardly than the end 132.

[0105] The description in the present disclosure is based on preferred embodiments. However, the present disclosure is not limited to these embodiments. The configuration of each element of the present disclosure can be replaced by a freely selected configuration with the same function of the aforementioned embodiment, and can include additional freely selected configurations. The freely selected configurations of the aforementioned embodiments can be combined with each other.

[0106] Description of Reference Numerals

[0107] 2. Sealing member, 2A. Sealing member, 2B. Sealing member, 3. Main body, 3A. Main body, 3B. Main body, 4. Sealing member, 6. Sealing cover, 11. Hub, 12. Inner ring, 13. Outer ring, 16. Steering knuckle, 17. Lifting ring, 18. Magnetic rubber, 19. Bolt, 20. Elastic ring, 20A. Elastic ring, 20B. Elastic ring, 25. Reinforcement ring, 25A. Reinforcement ring, 25B. Reinforcement ring, 31. Cylindrical portion, 32. Outer annular portion, 33. Inner annular portion, 41. First lip, 41A. First lip, 41B. First lip, 42. Second lip, 42A. Second lip, 42B. Second lip part, 43. third lip, 43A. third lip, 43B. third lip, 44. fourth lip, 60B. structural member, 61. fixed portion, 62. outer annular portion, 63. inner annular portion, 90. mixer, 91. cone, 100. hub bearing, 110. flange, 111. inner peripheral surface, 131. base, 132. end, 141. ball, 142. ball, 151. retainer, 152. retainer, 170. inner peripheral surface, 171. annular portion, 172. flange, AX. center axis, G1. first grease, G2. second grease, G3. third grease, and HX. opening.

Claims

1. A sealing device, the sealing device being used to seal an annular gap between an inner component and an outer component of a hub bearing, the inner component being rotatable relative to the outer component, the sealing device comprising: main body; a first lip that protrudes from the body; a second lip portion protruding from the body and positioned to be spaced apart from the first lip portion in a radially inward direction of the first lip portion; a first lubricating grease, the first lubricating grease being coated on a surface of the first lip; as well as A second lubricating grease is applied to the surface of the second lip, wherein: The first lip and the second lip each extend from the body toward the inner member or the outer member, and The first grease has properties that are different from the second grease.

2. The sealing device according to claim 1, wherein: The consistency value of the second grease specified in JIS K2220:2013 is different from the consistency value of the first grease specified in JIS K2220:2013.

3. The sealing device according to claim 2, wherein: The consistency value of the second lubricating grease specified in JIS K2220:2013 is smaller than the consistency value of the first lubricating grease specified in JIS K2220:2013.

4. The sealing device according to claim 1, wherein: The shear viscosity of the second lubricating grease in a sliding state is different from the shear viscosity of the first lubricating grease in a sliding state.

5. The sealing device according to claim 4, wherein: The shear viscosity of the second lubricating grease in a sliding state is smaller than the shear viscosity of the first lubricating grease in a sliding state.

6. The sealing device according to claim 1, wherein: The content percentage of the thickener in the second lubricating grease is different from the content percentage of the thickener in the first lubricating grease.

7. The sealing device according to claim 6, wherein: The content percentage of the thickener in the second lubricating grease is less than the content percentage of the thickener in the first lubricating grease.

8. The sealing device according to claim 1, wherein: The water resistance of the first lubricating grease is greater than the water resistance of the second lubricating grease.

9. The sealing device according to claim 1, wherein: The color density of the first lubricating grease is greater than the color density of the second lubricating grease.

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