Sealing device and bearing device

Abstract

To provide a sealing device capable of maintaining a proper amount of energization when arranged between a first member and a second member, and capable of suppressing deterioration of a lip piece.SOLUTION: Sealing devices 10A to 10E comprise a connection part 20 that can be electrically connected to a first member 2, and a lip part 40 that contacts a target surface on a second member 3 side. The lip part 40 comprises a lip base end part 41, and a conductive lip piece 43 that extends from the lip base end part 41 toward the target surface. The conductive lip piece 43 includes an elastic material 11, and integrally includes a conductive material 44 that is conductive at least at a tip end part 43a. The lip base end part 41 is mainly made of the elastic material 11.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a sealing device that is mounted between a first member and a second member that rotate relative to one another, and to a bearing assembly that includes the sealing device. [Background technology]

[0002] In the past, there was a problem that when an electric current flows through a bearing device that is made up of multiple rolling elements mounted between a first member and a second member, electrolytic corrosion occurs on the surface of the rolling elements, leading to early failure of the bearing. Electric vehicles in particular are equipped with many electrical components, so there is a risk that a large amount of electric current will flow through the bearing device.

[0003] To solve this problem, a technology has been proposed in which a conductive fiber material is placed inside a sealing device that is installed to seal the space between the first and second members of the bearing assembly, in order to guide the current that would otherwise flow to the rolling elements toward the sealing device.

[0004] In the sealing device of Patent Document 1, the fibrous material is arranged so that it extends radially and spans almost the entire length of the separation distance between the first member and the second member, and so that the ends of the fibrous material contact each of the first member and the second member.

[0005] In particular, since the first member and the second member are in a relative rotating relationship, the lip piece of the sealing device fixed to the first member is in sliding contact with the target surface of the second member (for example, the outer circumferential surface of the second member) during rotation. Therefore, the fiber material is arranged so that a part of the fiber material is exposed at the tip of the lip piece so that the electrical continuity is not interrupted while the lip piece is in sliding contact. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] DE102017107326 Summary of the Invention [Problem to be solved by the invention]

[0007] Incidentally, since the lip piece in the sealing device slides, typically the entire lip portion, including the lip base end portion (the root of the lip piece), is formed from an elastic material, and due to its flexibility, the lip piece is able to flexibly conform to the target surface against which it is subject to relative rotation and make sliding contact therewith.

[0008] However, in the sealing device of Patent Document 1, if the fiber material is arranged so as to extend over substantially the entire length of the sealing device between the first member and the second member, the fiber material may impair the flexibility of the lip piece and the lip base end. As a result, the sliding of the lip piece with the target surface on the second member side may become unstable, which may result in an unstable current flow state. In addition, the increased rigidity of the lip portion (less elastic deformation) may increase the reaction force of the lip piece against the target surface, which may cause heat generation and accelerate deterioration.

[0009] The present invention has been proposed in consideration of the above circumstances, and its object is to provide a sealing device and bearing device that can maintain a proper electrical current state when disposed between a first member and a second member that rotate relative to one another, and that can suppress deterioration of the lip piece. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, the sealing device of the present invention is a sealing device comprising an elastic material which, when mounted between a first member and a second member which rotate relative to one another, enables electrical connection between the first member and the second member, the sealing device comprising a connection portion which is electrically connectable to the first member and a lip portion which contacts a target surface on the second member side, the lip portion comprising a lip base end portion and a conductive lip piece which extends from the lip base end portion toward the target surface, the conductive lip piece including the elastic material and integrally including a conductive material having electrical conductivity at least at a tip portion, the lip base end portion being mainly made of the elastic material. Effect of the Invention

[0011] Since the sealing device of the present invention has the above-described configuration, when it is disposed between the first member and the second member, it is possible to maintain an appropriate electrical current state and to suppress deterioration of the lip piece. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic vertical cross-sectional view of a bearing assembly equipped with a sealing device according to an embodiment of the present invention (a view common to all embodiments). [Diagram 2] 1A and 1B are explanatory views of a sealing device according to a first embodiment, where FIG. 1A is a cut-away end view of the sealing device, and FIG. 1B is a partial vertical sectional view of a bearing unit to which the sealing device is attached. [Diagram 3] FIG. 1(a) is a cut-away end view of a sealing device according to a second embodiment, FIG. 1(b) is a cut-away end view of a sealing device according to a third embodiment, and FIG. 1(c) is a cut-away end view of a sealing device according to a fourth embodiment. [Figure 4] 13A and 13B are explanatory views of a sealing device according to a fifth embodiment, where FIG. 13A is a cut-away end view of the sealing device, and FIG. 13B is a partial vertical sectional view of a bearing unit to which the sealing device is attached. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. First, a schematic configuration of a bearing assembly 1 to which sealing devices 10A to 10E according to the following embodiments are attached will be described with reference to Fig. 1. Note that the drawings (see Figs. 2 to 4) relating to the various embodiments described below illustrate the sealing devices 10A to 10E at part X in Fig. 1.

[0014] The bearing device 1 comprises a first member 2 (outer member) and a second member 3 (inner member) that rotate relatively coaxially around the axis L of a shaft 5. For example, the first member 2 is fitted into a housing (not shown) or the like, the shaft 5 is inserted into the second member 3, and the second member 3 rotates together with the shaft 5, thereby establishing a relative rotation relationship between the first member 2 and the second member 3. In other words, the first member 2 is configured as the outer ring of the bearing, and the second member 3 is configured as the inner ring of the bearing.

[0015] Sealing devices 10A-10E are attached to seal a sealed space 6 between a first member 2 and a second member 3 in this bearing device 1 from both ends in the axial L direction, forming a sealed space. In the sealed space 6, a single row of rolling elements 7 (balls in the illustrated example) are held between the first member 2 and the second member 3 in a state where they are held by a retainer (not shown).

[0016] The sealing devices 10A to 10E of the present invention include various embodiments as described below. First, the common basic configuration of these sealing devices 10A to 10E will be described (see Figs. 2 to 4).

[0017] The sealing devices 10A to 10E each include a connection portion 20 that is electrically connectable to the first member 2, and a lip portion 40 that contacts a target surface on the second member 3 side. The lip portion 40 includes a lip base end portion 41 and a conductive lip piece 43 that extends from the lip base end portion 41 toward the target surface, and the conductive lip piece 43 includes an elastic material 11 and integrally includes a conductive material 44 having electrical conductivity at least at a tip end portion 43a. The lip base end portion 41 is mainly made of the elastic material 11.

[0018] All of the sealing devices 10A to 10E shown in Figures 2 to 4 are fitted (internal fit) into the first member 2, and with respect to the second member 3, the lip portion 40 is in sliding contact with a target surface on the second member 3 side (the first surface 3b of the stepped portion 3a of the second member 3 (see Figure 1), or the outer surface 51b of the slinger 50 of the sealing device 10E interposed between the second member 3 (see Figure 4(b))). In other words, the lip portion 40 is a portion for preventing water and other foreign matter from entering the sealed space 6 by minimizing the gap created by the relative rotation between the first member 2 and the second member 3.

[0019] In addition, in each of the sealing devices 10A to 10E described below, the elastic material 11, which is one of the components of the sealing devices 10A to 10E, is made of conductive rubber in which conductive carbon filler, etc., is mixed into the rubber material. Examples of the conductive carbon filler include carbon black, carbon fiber, carbon nanofiber, and graphite.

[0020] In addition, examples of materials for the conductive material 44 include conductive materials such as copper, tungsten, and stainless steel, and conductive fibers such as carbon fiber, and it is desirable to use a material that has at least a higher conductivity (lower resistivity) than ordinary rubber.

[0021] The conductive material 44 is desirably a flexible, flat material such as a thin film or a thin plate. A possible material for the conductive material 44 is, for example, a flexible metal mesh material made of a mesh of thin metal wires. It is also desirably to use a material having at least voids or through holes as the conductive material 44. The conductive material 44 is configured as an annular body formed to have an inner diameter equal to the tip diameter of the conductive lip piece 43. The conductive material 44 is provided so as not to be enclosed within the lip base end 41.

[0022] It is preferable that the conductive material 44 in the conductive lip piece 43 is integral with the elastic material 11 by the molten material, which is the raw material of the elastic material 11, impregnating the metal mesh material or entangling with the metal thin wire such as a metal fiber material during molding of the sealing devices 10A to 10E. When the conductive material 44 is a punching metal, it is preferable that the elastic material 11 enters the through holes.

[0023] Further, in each of the sealing devices 10A to 10E described below, a core part 30 is disposed along the radial direction so as to be adjacent to the connection part 20 side of the lip part 40. The core part 30 is composed of a core metal 31 and a part of the elastic material 11 fixed to the core metal 31. The core part 30 plays a role of increasing the rigidity of the sealing devices 10A to 10E so that the sealing devices 10A to 10E are stably fitted to the first member 2. The first member 2 and the second member 3 to which the sealing devices 10A to 10E are attached are made of a metallic material having electrical conductivity.

[0024] Next, the sealing devices 10A to 10E according to the respective embodiments will be described in order with reference to the drawings.

[0025] The sealing device 10A in Fig. 2 according to the first embodiment is integrally provided with a core metal 31, an elastic material 11, and a conductive material 44 as constituent materials. Fig. 2(a) is a cut end view of the sealing device 10A corresponding to part X in Fig. 1 when it is not installed in the sealed space 6, and Fig. 2(b) is a partial vertical sectional view of the bearing device 1 showing the installed state of the sealing device 10A. First, each part of the sealing device 10A will be described with reference to Fig. 2(a).

[0026] The core metal 31 is the main material constituting the core part 30 of the sealing device 10A, and is made of a metal material having higher rigidity than the elastic material 11, capable of being the core of the sealing device 10A, and having electrical conductivity. The core metal 31 includes a core metal cylindrical part 31a and a core metal disk part 31b extending radially inward from an outer lateral end part 31aa in the axial L direction. The conductive material 44 has an outer diameter set smaller than the inner diameter of the core metal disk part 31b of the core metal 31. In this embodiment, the elastic material 11 is disposed between the end face on the inner diameter side of the core metal disk part 31b and the end part on the outer diameter side of the conductive material 44.

[0027] In this embodiment, the connection portion 20 for electrically connecting with the first member 2 is formed to include an elastic material 11. The elastic material 11 is continuously disposed over substantially the entire radial length from the connection portion 20, through the core portion 30, to the lip portion 40. The connection portion 20 is formed with a protrusion portion 21 that fits into a groove portion 2a formed in the first member 2. In the core portion 30, the elastic material 11 is fixed to the outside in the axial L direction up to an inner end portion 31ba of the core metal disc portion 31b.

[0028] The lip portion 40 is composed of a lip base end portion 41 made of an elastic material 11, and two lip pieces 42, 43 extending so as to branch off from the lip base end portion 41. The lip base end portion 41 is formed thicker than either of the lip pieces 42, 43. Of the two lip pieces 42, 43, the lip piece 43 arranged on the outer side in the axial L direction (the side farther from the rolling elements 7) is configured such that the elastic material 11 on the outer side in the axial L direction and the conductive material 44 on the inner side in the axial L direction are fixed to each other so as to be in contact with each other. The lip piece 43 composed of these two members is the conductive lip piece 43 described above. The other lip piece 42 is composed of the elastic material 11.

[0029] When this sealing device 10A is mounted between the first member 2 and the second member 3, it comes to be in a state as shown in FIG. 2(b).

[0030] When the sealing device 10A is installed in the sealed space 6, on the first member 2 side, the core metal cylindrical portion 31a is in a state of being fitted into the first member 2 via the protrusion portion 21 of the connection portion 20, and the protrusion portion 21 is in a state of being compressed and inserted into the groove portion 2a.

[0031] On the other hand, on the second member 3 side, the conductive lip piece 43 is in elastic contact with the first surface 3b of the step portion 3a, and the other lip piece 42 is in contact with or close to the second surface 3c. During the rotational operation of the bearing device 1, at least the conductive lip piece 43 is elastically deformed and in sliding contact with the second member 3.

[0032] The conductive material 44 is exposed at least at the tip 43a of the conductive lip piece 43, and the exposed portion 44a contacts the first surface 3b of the second member 3 regardless of whether the bearing device 1 is rotating or stopped. Note that the exposed portion 44a is not limited to being exposed only at the end face of the tip 43a, but is preferably also exposed on the inner side surface in the axial L direction of the conductive lip piece 43 (a surface along the radial direction in cross section) as in the example of Fig. 2 in order to stabilize the sliding contact that allows conduction.

[0033] As can be seen from the above explanation and Figure 2(b), the connection portion 20 formed of the conductive elastic material 11 is in contact with the first member 2, and the exposed portion 44a of the conductive lip piece 43 is in contact with the second member 3, so that the sealing device 10A is in a state in which electrical conductivity can be established between the first member 2 and the second member 3 regardless of whether the bearing device 1 is rotating or stopped.

[0034] In particular, the electrical conductivity of the sealing device 10A as a whole can be increased by configuring the exposed portion 44a to contact the second member 3 over a large area in a state in which the conductive material 44 of the conductive lip piece 43 is fixed to the elastic material 11. For example, only the conductive material 44 may be made to protrude long toward the inner diameter side of the sealing device 10A.

[0035] Also, the lip portion 40 is provided with a lip base end 41 that does not include a conductive material 44. In other words, the lip base end 41 disposed between the core portion 30 (core metal 31) and the lip pieces 42, 43 does not include a conductive material 44 and is mainly made of the elastic material 11. In this way, since the lip base end 41 has a lower elasticity (is more easily deformed) than the core portion 30, even during relative rotation, the lip base end 41 elastically deforms slightly while the conductive lip piece 43 slides against the second member 3. Therefore, even during relative rotation, the conductive lip piece 43 slides against the second member 3, preventing interruption of electrical current.

[0036] Furthermore, the flexibility of the lip base end 41 of the lips 42, 43 reduces the reaction force caused by contact with the second member 3. This makes it possible to suppress heat generation due to sliding contact between the lips 42, 43, and to inhibit the progression of deterioration of the lips 42, 43. Even if a punching metal with low flexibility is used as the conductive material 44 of the conductive lip piece 43, the reaction force of the conductive lip piece 43 can be reduced as long as the lip base end 41 has sufficient flexibility.

[0037] Also, depending on the hardness of the conductive material 44, the conductive lip piece 43 may lose less flexibility than the other lip pieces 42, but by forming the conductive lip piece 43 by thinning the conductive material 44 or increasing the internal space capacity, the flexibility of the conductive lip piece 43 can be increased, so various adjustments can be made. If the lip base end 41 does not contain the conductive material 44 in the first place, there is almost no risk of the elasticity of the entire lip portion 40 being lost.

[0038] It has been confirmed by experiments conducted by the inventors that providing the conductive material 44 inside the lip portion 40 ensures electrical continuity between the first member 2 and the second member 3.

[0039] 2(a), before the sealing device 10A is attached, the conductive lip piece 43 and the conductive material 44 contained therein are substantially linear and flat in cross section. That is, when molding the sealing device 10A, the annular, flat conductive material 44 may be disposed in a mold (not shown) as it is without bending or the like before the molten material, which is the raw material of the elastic material 11, is injected.

[0040] Since there is no need to deform the flat conductive material 44 in the mold in this manner, the shape of the conductive material 44 will not become unstable due to elastic return within the mold, and therefore the manufacturing of the sealing device 10A can be carried out efficiently and quickly.

[0041] When molding the sealing device 10A in a mold, the molten material of the elastic material 11 penetrates into the gaps in the metal mesh material, and the impregnated molten material hardens, thereby bonding the elastic material 11 and the conductive material 44 to each other. Also, since the conductive material 44 is stably held in the mold, it is not necessary to bond or fix it in the mold. Furthermore, since the conductive material 44 does not need to be joined to the core metal 31 as in the illustrated example, the difficulty of bonding the three components, the core metal 31, the conductive material 44, and the elastic material 11 to each other can be avoided.

[0042] In this embodiment, the core metal 31 is used as the core material of the core part 30, but the core metal 31 may be replaced by a plate-like material of the same type as the conductive material 44, that is, a conductive metal mesh material or the like. This plate-like material may be less rigid than the core metal 31, but it is sufficient to use a plate-like material with increased rigidity by increasing its thickness. This plate-like material can also be used as is without deforming a flat plate, so it is easy to mold. As long as the elastic material 11 is conductive, a synthetic resin core material may be used instead of the core metal 31.

[0043] Next, sealing devices 10B, 10C, and 10D according to second, third, and fourth embodiments will be described with reference to Fig. 3(a), (b), and (c). These figures are cutaway end views of the sealing devices 10B, 10C, and 10D, which correspond to part X in Fig. 1, when not installed in the sealed space 6.

[0044] The first member 2 and the second member 3 of the bearing device 1 to which these sealing devices 10B and 10C are attached are similar to those to which the sealing device 10A shown in Fig. 2 is attached, and a groove portion 2a is formed in the first member 2, and a step portion 3a is formed in the second member 3. The attached state is not shown. The second member 3 of the bearing device 1 to which the sealing device 10D is attached has a step portion 3a similar to that to which the sealing device 10A is attached shown in Fig. 2, but as shown by the two-dot chain line in Fig. 3(c), the groove portion 2a is not formed in the fitting surface 2b of the first member 2.

[0045] In both of the sealing devices 10B and 10C according to the second and third embodiments (see Figs. 3(a) and (b)), similar to the sealing device 10A in Fig. 2, the core metal cylindrical portion 31a which is engaged with the first member 2 does not directly contact the first member 2, but contacts the first member 2 by the connection portion 20 entering the groove portion 2a. On the other hand, in the sealing device 10D according to the fourth embodiment (see Fig. 3(c)), both the core metal cylindrical portion 31a and the connection portion 20 directly contact the fitting surface 2b of the first member 2.

[0046] In the sealing device 10B shown in Fig. 3(a), the connection portion 20 and the core portion 30 are configured in a manner similar to those in Fig. 2. However, the elastic material 11 and the core metal 31 in the core portion 30 are arranged in the order of the core metal 31 and the elastic material 11 from the outside in the axial L direction.

[0047] Furthermore, the lip portion 40 is generally similar to that shown in Figure 2, and has a lip base end portion 41 and two lip pieces 42, 43, which are arranged from the outside in the axial L direction as follows: conductive lip piece 43, then other lip piece 42.

[0048] The conductive lip piece 43 is formed so that its overall thickness is equal to the thickness of the conductive material 44. The conductive lip piece 43 has the elastic material 11 inserted into the internal gap of the conductive material 44, and is made of the same material as that shown in Fig. 2. Since the conductive lip piece 43 is formed thinner in this way, the reaction force when it comes into contact with the second member 3 can be reduced.

[0049] In addition, the lip base end 41 is formed thinner than adjacent parts in the radial direction (core part 30, lip pieces 42, 43) and has a constricted shape in cross section. In other words, the lip base end 41 is formed so that it becomes thicker from the thinnest point toward the inner diameter side and toward the outer diameter side. Therefore, the lip base end 41 elastically deforms more flexibly. As a result, it is possible to prevent the reaction force of the lip pieces 42, 43 from becoming too high.

[0050] Other effects of the sealing device 10B are similar to those of the sealing device shown in FIG. 2, and therefore will not be described.

[0051] In the sealing device 10C shown in Fig. 3(b), the connection portion 20 and the core portion 30 are almost the same as those in Fig. 2. The arrangement of the elastic member 11 and the core metal 31 in the core portion 30 is the same as that in Fig. 2.

[0052] The lip portion 40 has a configuration generally similar to that of Fig. 2. However, the lip portion 40 has a lip base end portion 41, and also has three lip pieces 42, 43. Of the lip pieces 42, 43, the lip piece 43 located in the center is used as the conductive lip piece 43.

[0053] The conductive lip piece 43 extends radially inward and axially inward. The conductive material 44 of the conductive lip piece 43 is slightly inclined downward toward the radially inward side, but is linear in cross section. Therefore, when molding the sealing device 10B using a mold, a flat conductive material 44 may be used with a concave inner diameter side, or a cone-shaped conductive material 44 with an open bottom may be used. There is no need to change the shape of the conductive material 44 by curving or bending it partway in the radial direction inside the mold, and the arrangement does not require much effort.

[0054] Other effects of the sealing device 10B are similar to those of the sealing device shown in FIG. 2, and therefore will not be described.

[0055] The sealing device 10D shown in Fig. 3(c) has a lip portion 40 that is generally similar to that shown in Fig. 3(b). That is, the lip portion 40 includes a lip base end portion 41 and three lip pieces 42 and 43, and the lip piece 43 disposed in the center is the conductive lip piece 43.

[0056] The connecting portion 20 is configured such that the elastic material 11 and the core cylindrical portion 31a are aligned in the axial direction L, and the core cylindrical portion 31a, which is engaged with the first member 2, directly contacts the mating surface 2b of the first member 2. The arrangement of the elastic material 11 and the core 31 in the core portion 30 is the same as that in FIG.

[0057] Furthermore, the connecting portion 20 is formed with a protruding pressure-contact portion 22 made of an elastic material 11, and is pressure-contacted with the fitting surface of the first member 2 to complement the fitting by the core metal 31.

[0058] Since the core metal 31 is in direct contact with the first member 2, if the core metal 31 is made of a metal material, the sealing device 10D and the first member 2 can be electrically connected by the core metal 31. Therefore, the elastic material 11 may not be conductive, but if an adhesive is used to fit the core metal 31 to the first member 2, there is a risk that the conductivity between the core metal 31 and the first member 2 may be impaired, so it is preferable to use an elastic material 11 that has conductivity.

[0059] In addition, since the connection portion 20 is responsible for the electrical connection with the first member 2, when a non-conductive elastic material 11 is used, it goes without saying that the core metal cylindrical portion 31a is the part that engages with the first member 2 and also functions as the connection portion 20.

[0060] Other effects of the sealing device 10D are similar to those of the sealing device shown in FIG. 2, and therefore will not be described.

[0061] Next, a sealing device 10E according to a fifth embodiment will be described with reference to Fig. 4. Fig. 4(a) is a cutaway end view of the sealing device 10E corresponding to part X in Fig. 1 when not installed in the sealed space 6, and Fig. 4(b) is a partial vertical sectional view of the bearing device 1 showing the installed state of the sealing device 10E. First, each part of the sealing device 10E will be described with reference to Fig. 4(a).

[0062] 4 is composed of two separate members, a sealing member 15 and a slinger 50, which are integrally installed in the sealed space 6 of the bearing device 1. The sealing member 15 is fitted (inside) into the first member 2, while the slinger 50 is fitted (outside) into the second member 3.

[0063] The sealing member 15 generally corresponds to the sealing devices 10A according to the first to fourth embodiments, and has a connection portion 20, a core portion 30, and a lip portion .

[0064] 3(c), the connection part 20 is configured such that the elastic material 11 and the core cylindrical part 31a are arranged side by side in the axial direction L, and the core cylindrical part 31a, which is responsible for fitting with the first member 2, directly contacts the first member 2. Note that the connection part 20 is formed with a protruding pressure contact part 22 made of the elastic material 11, which is pressed against the fitting surface of the first member 2 to complement the fitting by the core 31.

[0065] 3(c), the open end of the core metal cylindrical portion 31a is disposed on the outside in the direction of the axis L. The core material portion 30 is arranged in the same manner as in FIG.

[0066] The lip portion 40 has a lip base end portion 41 and two lip pieces 42, 43, which are arranged in the order of the conductive lip piece 43 and the other lip piece 42 from the outside in the axial L direction.

[0067] On the other hand, the slinger 50 is made of a metal material and has a first cylindrical portion 51 that contacts the second member 3, a slinger disc portion 52 that extends radially outward from the lateral end portion 51a of the first cylindrical portion 51, and a second cylindrical portion 53 that extends toward the sealed space 6 from the outer end portion 52a of the slinger disc portion 52.

[0068] The core metal cylindrical portion 31a of the sealing member 15 is fitted (inner fit) into the first member 2, and the first cylindrical portion 51 of the slinger 50 is fitted (outer fit) into the second member 3, so that the sealing member 15 and the slinger 50 are attached to the sealed space 6 (see Figure 1) as a sealing device 10E.

[0069] The slinger 50 is preferably fixed to the second member 3 with an adhesive, but it is also preferable to leave the slinger 50 and the second member 3 in electrical contact with each other without using adhesive between the inner surface of the first cylindrical portion 51 and the outer surface 3d of the second member 3. The relationship between the first member 2 and the core metal cylindrical portion 31a, and the relationship between the first member 2 and the connecting portion 20 are the same as those shown in Fig. 3(c).

[0070] When the sealing device 10E is in the installed state, a labyrinth space r is formed by the sealing member 15 and the slinger 50. Both of the two lip pieces 42, 43 of the sealing member 15 contact the outer surface 51b of the first cylindrical portion 51 on the second member 3 side at the back of the labyrinth space r. That is, the exposed portion 44a of the conductive material 44 included in the conductive lip piece 43 contacts the outer surface 51b of the first cylindrical portion 51. When the first member 2 and the second member 3 are in a relative rotation state, the tips of the lip pieces 42, 43 elastically and slidably contact the surface side of the second member 3 facing the first member 2, that is, the outer surface 51b of the first cylindrical portion 51.

[0071] The lip pieces 42, 43 may be configured to be in sliding contact with the side surface 52b facing the labyrinth space r of the slinger disc portion 52. Also, in consideration of a case where the slinger 50 and the second member 3 are not electrically connected by an adhesive, the lip piece 42 (the one on the left in FIG. 4(b)) may be configured to contact the outer surface 3d of the second member 3 as the conductive lip piece 43.

[0072] In this way, when the sealing device 10E is attached between the first member 2 and the second member 3, the connection portion 20 enables electrical conductivity with the first member 2, and the conductive lip piece 43 enables electrical conductivity with the second member 3 via the slinger 50, thereby enabling electrical conductivity between the first member 2 and the second member 3.

[0073] Other effects of the sealing device 10E are similar to those of the sealing device 10E shown in FIG. 3, and therefore will not be described.

[0074] The sealing devices 10A to 10E described above have the first member 2 (outer member) as the fixed side and the second member 3 (inner member) as the rotating side, but the first member 2 may be the rotating side and the second member 3 as the fixed side. Even in that case, the sealing devices 10A to 10E are similar to those described above in that the connection portion 20 is disposed on the first member 2 side and the lip portion 40 is disposed on the second member 3 side.

[0075] In addition, in the sealing devices 10A to 10E, the exposed portion 44a of the conductive material 44 is provided at the tip portion 43a of the conductive lip piece 43, but the conductive lip piece 43 includes the elastic material 11 having conductivity, and since the elastic material 11 alone can exhibit conductivity, the conductive material 44 may not have the exposed portion 44a. In other words, the conductive material 44 may be covered by the elastic material 11 as long as it is provided at the tip portion of the conductive lip piece 43 and exhibits the function of assisting the conductivity of the sealing devices 10A to 10E.

[0076] In the sealing devices 10A to 10E, there is no limitation on the amount or length of the conductive material 44 contained in the conductive lip piece 43. For example, the radial length of the conductive material 44 does not need to match the entire length of the conductive lip piece 43, and may be arranged, for example, in a part of the base end side, a part of the tip end side, or a part in the center of the conductive lip piece 43.

[0077] In this way, since the conductive material 44 only needs to be arranged over the entire length or part of the conductive lip piece 43, costs can be reduced compared to when the conductive material 44 is arranged over approximately the entire length from the end on the first member 2 side to the end on the second member 3 side.

[0078] Further, the conductive lip piece 43 is not limited to being provided in only one of the sealing devices 10A to 10E, and a plurality of conductive lip pieces 43 may be provided in any sealing device provided with a plurality of lip pieces.

[0079] The material of the conductive material 44 in the sealing devices 10A to 10E is not limited to a metal mesh material, but may be a plate-shaped metal material having through holes, such as a flexible punched metal made of a metal plate material itself. Even in this case, the conductive material 44 can ensure a predetermined flexibility by having through holes. Furthermore, the conductive material 44 may be made of a plate-shaped metal material without through holes, so long as the predetermined flexibility can be ensured. Furthermore, the material used for the conductive material 44 is not limited to a metal material, but may be a resin film having conductivity.

[0080] The sealing devices 10A to 10E according to the various embodiments described above are merely examples. It goes without saying that the overall shape of the sealing devices 10A to 10E can be appropriately changed to a shape other than that shown in the drawings as a design matter, for example, depending on the shape of the bearing device 1 to be mounted.

[0081] Furthermore, the sealing device of the present invention is not limited to being applied to the bearing device 1, and may be applied to, for example, an oil seal mounted between a housing and a rotating shaft. Furthermore, it is not limited to a bearing seal or an oil seal, and may be a seal for other applications as long as it seals between a first member and a second member that rotate relatively. [Explanation of symbols]

[0082] 1 Bearing device 2 First member 2a Groove 2b Mating surface 3 Second member 3a Step part 3b Side 1 3c 2nd side 3d exterior 5 Shaft 6 Sealed space 7 Rolling elements 10A~10E Sealing device 11 Elastic material 15 Sealing material 20 Connection 21 Projection part 22 Pressure Welding Part 30 Core 31 Core 31a Core cylinder 31aa lateral end 31b Core metal disc part 31ba inner end 40 Lip 41 Lip base end 42 Lip piece 43 Conductive lip piece (lip piece) 43a Tip 44 Conductive materials 44a Exposed part 50 Slinger 51 First cylindrical section 51a Side end 51b External surface 52 Slinger disc 52a Outer end 52b Side 53 Second cylindrical section

Claims

1. A sealing device including an elastic material, the sealing device being capable of electrically connecting a first member and a second member that rotate relative to each other when the sealing device is mounted between the first member and the second member, A connection portion that can be electrically connected to the first member; a lip portion that contacts a target surface on the second member side, the lip portion includes a lip base end portion and a conductive lip piece extending from the lip base end portion toward the target surface, the conductive lip piece including the elastic material and integrally including a conductive material having electrical conductivity at least at a tip portion thereof, A sealing device characterized in that the base end of the lip is mainly made of the elastic material.

2. In claim 1, A sealing device characterized in that the elastic material is a conductive rubber and is disposed continuously from the connection portion to the tip portion of the conductive lip piece.

3. In claim 1, A sealing device, characterized in that the lip base end portion is formed without including the conductive material.

4. In claim 1, A sealing device, characterized in that a core portion extending in a radial direction is disposed, and the lip base end portion is interposed between the core portion and the conductive material.

5. In claim 1, A sealing device, characterized in that the conductive material is substantially linear in cross-sectional view and is formed so as to overlap the elastic material.

6. In claim 1, The conductive material is a metal mesh material formed by braiding thin metal wires, A sealing device characterized in that the elastic material is impregnated into the metal mesh material and fixed to the conductive material.

7. In claim 1, The conductive material is a metal material, and a plurality of through holes are formed in the metal material, The sealing device according to claim 1, wherein the elastic material is fixed to the conductive material so as to be entangled with the through hole.

8. In claim 1, A sealing device characterized in that the lip portion has a plurality of lip pieces, at least one of which is the conductive lip piece, and the conductive lip piece is formed so as to be arranged on the outside in the axial direction.

9. In claim 1, A sealing device, characterized in that the connection portion has a protrusion portion that fits into a groove portion formed in the first member.

10. In claim 1, A sealing device characterized in that the lip base end portion has a constricted shape in cross section.

11. A bearing device, characterized in that the sealing device according to any one of claims 1 to 10 is mounted between an outer ring as the first member and an inner ring as the second member.

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