Electrically conductive structure and electrically conductive hermetically sealing device

Abstract

To provide an electrically conductive structure which can be saved in space and furthermore can be suppressed in reduction of electrically conductive performance in use.SOLUTION: An electrically conductive structure (1) comprises: a holding member (2) which is an annular member around an axis line (x) and has electric conductivity; and an electrically conductive member (3) which is an annular member around the axis line (x). The electrically conductive member (3) has a gap (10) provided in such a manner as to extend in at least one radial direction, and a conductor (20) having electric conductivity and extending around at least one axis line x. The electrically conductive member (3) is held by a holding member (2). The conductor (20) has a pair of ends (20a, 20b) in a direction around the axis line x. The gap (10) continues to the ends (20a, 20B) of the conductor (20).SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a conductive structure and a conductive sealing device, and particularly to a conductive structure and a conductive sealing device that form a conductive path on a rotating shaft.

Background Art

[0002] For example, in a vehicle equipped with an electric motor such as an electric vehicle (EV: Electric Vehicle), electromagnetic wave noise may be generated by an induced current or the like generated from the motor. Such electromagnetic wave noise may cause communication failures in AM radios and other wireless communication devices. Further, such electromagnetic wave noise may cause electrolytic corrosion in metal parts such as bearings. For this reason, conventionally, devices for removing such electromagnetic wave noise have been devised, and conductive structures and conductive devices that form a conductive path on a rotating shaft have been proposed. For example, a technique is disclosed in which an oil seal that seals a rotating shaft of a motor is an oil seal made of conductive rubber, a conductive path is formed on the rotating shaft, and electromagnetic wave noise is released from the rotating shaft to the housing (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For an oil seal, a lubricant is used for lubrication, and in the operating state, an oil film is formed between the seal lip and the rotating shaft. For an oil seal having conductive rubber, a conductive lubricant is used for lubrication. Even if the oil film formed between the conductive seal lip and the rotating shaft is formed by a conductive lubricant, the oil film can become a resistance to current between the conductive seal lip and the rotating shaft. Therefore, even when a conductive lubricant is used, the conductivity between the seal lip and the rotating shaft may decrease. On the other hand, an oil seal having conductive rubber does not require an additional space in the mounting space of the oil seal. Thus, the conventional conductive structures and conductive devices as described above can save space, but the conductive performance may decrease in the operating state. For this reason, there is a need for a configuration that can suppress a decrease in conductive performance in the operating state while enabling space saving for the conventional conductive structures and conductive devices.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a conductive structure and a conductive sealing device that can suppress a decrease in conductive performance in the operating state while enabling space saving.

Means for Solving the Problems

[0006] To achieve the above object, a conductive structure according to the present invention includes a holding member that is an annular member having conductivity around an axis, and a conductive member that is an annular member around the axis. The conductive member has at least one gap provided so as to extend in the radial direction and at least one conductor having conductivity extending around the axis. The conductive member is held by the holding member. The conductor has a pair of ends in the direction around the axis, and the gap is continuous with the ends of the conductor.

[0007] In one aspect of the conductive structure according to the present invention, the conductive member has one of the conductors and also has one of the gaps. The pair of ends of the conductor face each other in the direction around the axis, and the gap is a gap between the opposing ends of the conductor.

[0008] In one aspect of the conductive structure according to the present invention, the conductive member has two of the conductors and also has two of the gaps. One of the pair of ends of one of the conductors faces one of the pair of ends of the other conductor in the direction around the axis, and the other of the pair of ends of one of the conductors faces the other of the pair of ends of the other conductor in the direction around the axis. One of the gaps is formed between one end of one of the conductors and one end of the other conductor, and the other of the gaps is formed between the other end of one of the conductors and the other end of the other conductor.

[0009] In one aspect of the conductive structure according to the present invention, the conductor is held by the holding member on the outer peripheral side.

[0010] In one aspect of the conductive structure according to the present invention, an annular spring member is provided around the axis, and the spring member is configured to generate an elastic force in the direction toward the axis. The spring member is provided side by side with the conductive member in the axial direction.

[0011] In one aspect of the conductive structure according to the present invention, the holding member has at least one protruding portion that is received in the gap, and the protruding portion protrudes in the axial direction.

[0012] In one aspect of the conductive structure according to the present invention, the conductor is formed of conductive PTFE.

[0013] To achieve the above object, a conductive sealing device according to the present invention is a conductive sealing device for sealing between a shaft and a hole through which the shaft passes, and includes a reinforcing ring which is an annular member around an axis, an elastic body portion formed from an annular elastic body attached to the reinforcing ring, and an annular conductive structure around the axis. The elastic body portion has a seal lip that contacts the shaft. The conductive structure has a holding member which is an annular member around the axis and a conductive member which is an annular member around the axis. The conductive member has at least one gap extending in the radial direction and at least one conductor having conductivity extending around the axis. The holding member is attached to the elastic body portion and holds the conductor between the elastic body portion. The conductor has a pair of ends in the direction around the axis, and the gap is continuous with the ends of the conductor.

[0014] In one aspect of the conductive sealing device according to the present invention, the conductive member has one of the conductors and also has one of the gaps. The pair of ends of the conductor face each other in the direction around the axis, and the gap is a gap between the opposing ends of the conductor.

[0015] In one aspect of the conductive sealing device according to the present invention, the conductive member has two of the conductors and also has two of the gaps. One of the pair of ends of one of the conductors and one of the pair of ends of the other conductor face each other in the direction around the axis. The other of the pair of ends of one of the conductors and the other of the pair of ends of the other conductor face each other in the direction around the axis. One of the gaps is formed between one end of the one conductor and one end of the other conductor. The other of the gaps is formed between the other end of the one conductor and the other end of the other conductor.

[0016] In one aspect of the conductive sealing device according to the present invention, the holding member has at least one protruding portion accommodated in the gap, and the protruding portion protrudes in the axial direction.

[0017] In one aspect of the conductive sealing device according to the present invention, the conductor is formed of conductive PTFE.

Effects of the Invention

[0018] According to the present invention, it is possible to provide a conductive structure and a conductive sealing device that can suppress a decrease in conductive performance in a use state while enabling space saving.

Brief Description of the Drawings

[0019]

Figure 1

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Figure 20

MODE FOR CARRYING OUT THE INVENTION

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, not all of the plurality of components are labeled, and some of the labels of the plurality of components may be omitted.

[0021] The conductive structure according to the embodiment of the present invention forms a conductive path on a rotating shaft. For example, a conductive path is formed between the shaft and the hole through which the shaft is inserted. Note that the application target to which the conductive structure according to the embodiment of the present invention is applied is not limited to this. FIG. 1 is a perspective view showing a schematic configuration of the conductive structure 1 according to the first embodiment of the present invention, FIG. 2 is a front view of the conductive structure 1 shown in FIG. 1, and FIG. 3 is a cross-sectional view showing one side with respect to the axis x of a cross-section by a plane including the axis x of the conductive structure 1.

[0022] As shown in FIGS. 1 to 3, the conductive structure 1 includes a holding member 2 which is a member having annular conductivity around the axis x, and a conductive member 3 which is an annular member around the axis x. The conductive member 3 has at least one gap 10 provided so as to extend in the radial direction and at least one conductor 20 having conductivity and extending around the axis x. The conductive member 3 is held by the holding member 2. The conductor 20 has a pair of ends 20a and 20b in the direction around the axis x. The gap 10 is continuous with the ends 20a and 20b of the conductor 20. Hereinafter, the configuration of the conductive structure 1 will be specifically described.

[0023] As shown in FIGS. 1 to 3 for example, the conductive member 3 has two gaps 10 and two conductors 20. Specifically, the conductive member 3 has gaps 11 and 12 as the gaps 10 and conductors 21 and 22 as the conductors 20. The conductors 21 and 22 have conductivity and are formed of a material having conductivity. The material of the conductor 20 (conductors 21 and 22) is, for example, conductive PTFE (polytetrafluoroethylene). The material of the conductor 20 is not limited to conductive PTFE, and may be, for example, other resins having conductivity, rubbers having conductivity, or fibers such as non-woven fabrics having conductivity.

[0024] FIG. 4 is a front view of the conductive member 3 in the conductive structure 1. As shown in FIGS. 1 to 4, the conductive member 3 is an annular plate-like structure composed of two gaps 10 (gaps 11 and 12) and two conductors 20 (conductors 21 and 22) in the conductive structure 1. As shown in FIG. 4, the conductor 21 has a pair of ends 21a and 21b as a pair of ends 20a and 20b, and the conductor 22 has a pair of ends 22a and 22b as a pair of ends 20a and 20b. One of the pair of ends (end 21a) of one of the conductors 20 (conductor 21) and one of the pair of ends (22a) of the other of the conductors 20 (conductor 22) face each other in the direction around the axis x (circumferential direction). Also, the other of the pair of ends (end 21b) of the conductor 21 and the other of the pair of ends (end 22b) of the conductor 22 face each other in the direction around the axis x (circumferential direction). One of the gaps 10 (gap 11) is formed between the end 21a of the conductor 21 and the end 22a of the conductor 22, and the other of the gaps 10 (gap 12) is formed between the end 21b of the conductor 21 and the end 22b of the conductor 22.

[0025] As shown in FIGS. 2 and 4, the conductors 21 and 22 are plate-like members extending along an arc around the axis x, and for example, extend along an arc or a substantially arc centered or substantially centered on the axis x. Also, as shown in FIG. 3, the conductor 21 has a base portion 23 that is a portion extending along a plane and a contact portion 24 that extends obliquely in the direction of the axis x from the base portion 23.

[0026] As shown in FIGS. 3 and 4, the base 23 is a plate-like portion and has side surfaces 23a and 23b which are, for example, surfaces facing away from each other in the direction of the axis x. The side surface 23a extends along a plane orthogonal to the axis x, for example, extends on a surface parallel or substantially parallel to the plane orthogonal to the axis x. Similarly, the side surface 23b extends along a plane orthogonal to the axis x, for example, extends on a surface parallel or substantially parallel to the plane orthogonal to the axis x. Note that the side surface 23a faces the front side (right side in the direction of the axis x in FIG. 3). As shown in FIG. 4, the side surfaces 23a and 23b extend so as to draw an arc or a substantially arc. Further, the outer peripheral side end (outer peripheral end 23c) of the base 23 extends along a circle centered on the axis x.

[0027] As shown in FIG. 3, the contact portion 24 extends obliquely from the inner peripheral side end of the base 23 toward the side (front side) where the side surface 23a of the base 23 faces. The contact portion 24 is a plate-like portion and has, for example, side surfaces 24a and 24b which are surfaces facing away from each other. The contact portion 24 has a shape such that the diameter decreases as it goes toward the front side in the direction of the axis x. The contact portion 24 is formed such that, for example, as shown in FIG. 3, the shape of a cross section (hereinafter, also simply referred to as a "cross section") by a plane including the axis x is along an arc. Specifically, for example, as shown in FIG. 3, in the cross section, the side surface 24a draws an arc or a substantially arc convex toward the inner peripheral side. Similarly, the side surface 24b draws an arc or a substantially arc convex toward the inner peripheral side. The side surface 24a is connected to the side surface 23a of the base 23, and the side surface 24b is connected to the side surface 23b of the base 23. Further, the inner peripheral side end (inner peripheral end 24c) of the contact portion 24 extends along a circle centered on the axis x, for example, extends on a circle or a substantially circle centered or substantially centered on the axis x.

[0028] In the usage state where the conductive structure 1 is attached to the application target, the end on the inner circumferential side of the contact portion 24 comes into contact with the outer circumferential surface of the axis of the application target. Specifically, the diameter of the inner circumferential end 24c of the contact portion 24 is set corresponding to the diameter of the outer circumferential surface of the axis of the application target. For example, it is the same as or smaller than the diameter of the outer circumferential surface of the axis. As shown in FIG. 3, for example, in cross-section, the conductor 21 has a uniform or substantially uniform thickness. Note that the thickness of the conductor 21 at the base portion 23 is the distance between the side surface 23a and the side surface 23b, and at the contact portion 24, it is the distance between the side surface 24a and the side surface 24b. Note that the conductor 21 does not necessarily have a uniform thickness.

[0029] As shown in FIGS. 3 and 4, the conductor 21 extends in the circumferential direction so as to be shorter than a semi-circle of a circle along which the conductor 21 extends. That is, the conductor 21 extends in the circumferential direction such that both the end 21a and the end 21b of the conductor 21 are located on one plane including the axis x or do not exceed one plane including the axis x. As shown in FIG. 4, the ends 21a and 21b of the conductor 21 extend parallel or substantially parallel to the plane including the axis x, for example, and face each other in a direction orthogonal to the axis x. Note that the ends 21a and 21b of the conductor 21 do not necessarily extend parallel to the plane including the axis x.

[0030] Note that the cross-sectional shape of the conductor 21 is not limited to the above-described cross-sectional shape and can be various cross-sectional shapes. For example, as shown in FIG. 5, the contact portion 24 of the conductor 21 may have a shape that extends along a conical surface having the axis x as the central axis. Also, for example, as shown in FIG. 6, the contact portion 24 of the conductor 21 is not inclined with respect to the base portion 23, and the side surface 23a and the side surface 24a may be flush, and the side surface 23b and the side surface 24b may be flush. Also, the contact portion 24 of the conductor 21 may have a shape that extends along another curve in cross-section, or may have a shape that extends along a line formed by a combination of a curve and a straight line.

[0031] As shown in FIGS. 3 and 4, the conductor 22 has a base portion 25 and a contact portion 26, similar to the conductor 21. The conductor 22 is formed in the same manner as the conductor 21 and has the same or substantially the same shape as the conductor 21. The ends 22a and 22b of the conductor 22 correspond to the ends 21a and 21b of the conductor 21. The base portion 25 and the contact portion 26 of the conductor 22 correspond to the base portion 23 and the contact portion 24 of the conductor 21, respectively. The side surfaces 25a, 25b, and the outer peripheral end 25c of the base portion 25 of the conductor 22 correspond to the side surfaces 23a, 23b, and the outer peripheral end 23c of the base portion 23 of the conductor 21, respectively, and the side surfaces 26a, 26b, and the inner peripheral end 26c of the contact portion 26 of the conductor 22 correspond to the side surfaces 24a, 24b, and the inner peripheral end 24c of the contact portion 24 of the conductor 21, respectively. Note that the conductor 22 does not have to be formed in the same manner as the conductor 21, and does not have to have the same shape as the conductor 21.

[0032] As shown in FIGS. 2 and 4, in the conductive member 3 of the conductive structure 1, the conductors 21 and 22 and the gaps 11 and 12, which are the respective components, are located on a circle or a substantially circular shape centered around or substantially centered around the axis x. Specifically, for example, the conductor 21 and the conductor 22 are arranged to be symmetric with respect to a plane including the axis x. Further, the conductors 21 and 22 are arranged such that the inner peripheral end 24c of the contact portion 24 of the conductor 21 and the inner peripheral end 26c of the contact portion 26 of the conductor 22 are located on a circle or a substantially circular shape centered around or substantially centered around the axis x. The end 21a of the conductor 21 and the end 22a of the conductor 22 face each other in a direction orthogonal to the axis x, and the end 21b of the conductor 21 and the end 22b of the conductor 22 face each other in a direction orthogonal to the axis x. Thereby, a gap 11 is formed between the end 21a of the conductor 21 and the end 22a of the conductor 22, and a gap 12 is formed between the end 21b of the conductor 21 and the end 22b of the conductor 22. In this way, the gap 11 is continuous with the end 21a of the conductor 21 and the end 22a of the conductor 22, and the gap 12 is continuous with the end 21b of the conductor 21 and the end 22b of the conductor 22.

[0033] As shown in FIGS. 1 to 3, specifically, the holding member 2 has an inner holding member 30 located inside and an outer holding member 40 located outside. The inner holding member 30 and the outer holding member 40 are annular members around the axis x, and are configured to hold the conductive member 3 between them.

[0034] As shown in FIG. 3, for example, the inner holding member 30 has a fitting portion 31 that is an annular portion around the axis x and a holding portion 32 that is an annular portion around the axis x. The fitting portion 31 is a cylindrical portion extending along the axis x, and the holding portion 32 is an annular portion extending from the end of the fitting portion 31 toward the inner peripheral side.

[0035] As shown in FIG. 3, for example, the fitting portion 31 has an outer peripheral surface 31a and an inner peripheral surface 31b that are surfaces facing away from each other in the radial direction orthogonal to the axis x direction, and has a rectangular or substantially rectangular cross-sectional shape. The outer peripheral surface 31a is a surface facing the outer peripheral side, and the inner peripheral surface 31b is a surface facing the inner peripheral side. The outer peripheral surface 31a is a cylindrical surface extending along the axis x, and is, for example, a cylindrical surface or a substantially cylindrical surface having the axis x as the central axis or a substantially central axis. Similarly, the inner peripheral surface 31b is a cylindrical surface extending along the axis x, and is, for example, a cylindrical surface or a substantially cylindrical surface having the axis x as the central axis or a substantially central axis.

[0036] As shown in FIG. 3, for example, the holding portion 32 has side surfaces 32a and 32b that are surfaces facing away from each other in the axis x direction, and has a rectangular or substantially rectangular cross-sectional shape. The side surface 32a extends along a plane orthogonal to the axis x, and extends, for example, on a surface parallel or substantially parallel to the plane orthogonal to the axis x. Similarly, the side surface 32b extends along a plane orthogonal to the axis x, and extends, for example, on a surface parallel or substantially parallel to the plane orthogonal to the axis x. As shown in FIGS. 2 and 3, the side surfaces 32a and 32b extend along a circle centered on the axis x. The side surface 32a is connected to the outer peripheral surface 31a of the fitting portion 31, and the side surface 32b is connected to the inner peripheral surface 31b of the fitting portion 31.

[0037] As shown in FIG. 3, the outer holding member 40 has, for example, a fitting portion 41 that is an annular portion around the axis x and a holding portion 42 that is an annular portion around the axis x. The fitting portion 41 is a cylindrical portion extending along the axis x, and the holding portion 42 is an annular portion extending from the end of the fitting portion 41 toward the inner peripheral side.

[0038] As shown in FIG. 3, the fitting portion 41 has, for example, an outer peripheral surface 41a and an inner peripheral surface 41b that are surfaces facing away from each other in the direction of the axis x, and the cross-sectional shape is substantially rectangular. The outer peripheral surface 41a is a surface facing the outer peripheral side, and the inner peripheral surface 41b is a surface facing the inner peripheral side. The outer peripheral surface 41a is a cylindrical surface extending along the axis x, and is, for example, a cylindrical surface or a substantially cylindrical surface having the axis x as the central axis or a substantially central axis. Similarly, the inner peripheral surface 31b is a cylindrical surface extending along the axis x, and is, for example, a cylindrical surface or a substantially cylindrical surface having the axis x as the central axis or a substantially central axis. Further, as shown in FIG. 3, a pressing portion 43, which is a protruding portion protruding toward the inner peripheral side, is formed at the front end of the fitting portion 41. Specifically, the pressing portion 43 protrudes from the inner peripheral surface 41b toward the inner peripheral side. The pressing portion 43 extends annularly around the axis x, for example, as shown in FIGS. 1 and 3. Note that the pressing portion 43 does not have to extend continuously annularly around the axis x, and may extend intermittently annularly around the axis x. The pressing portion 43 may be formed, for example, by intermittently arranging protruding portions extending in an arc shape along a circle centered on the axis x.

[0039] As shown in FIG. 3, the holding portion 42 has, for example, side surfaces 42a and 42b that are surfaces facing away from each other in the direction of the axis x, and the cross-sectional shape is rectangular or substantially rectangular. The side surface 42a extends along a plane orthogonal to the axis x, and extends, for example, on a surface parallel or substantially parallel to the plane orthogonal to the axis x. Similarly, the side surface 42b extends along a plane orthogonal to the axis x, and extends, for example, on a surface parallel or substantially parallel to the plane orthogonal to the axis x. The side surfaces 42a and 42b extend along a circle centered on the axis x. The side surface 42a is connected to the outer peripheral surface 41a of the fitting portion 41, and the side surface 42b is connected to the inner peripheral surface 41b of the fitting portion 41.

[0040] As shown in FIG. 3, the fitting portion 31 of the inner holding member 30 and the fitting portion 41 of the outer holding member 40 are adapted to be fitted to each other. Specifically, for example, the outer peripheral surface 31a of the fitting portion 31 of the inner holding member 30 and the inner peripheral surface 41b of the fitting portion 41 of the outer holding member 40 are adapted to contact each other. For example, the diameter of the outer peripheral surface 31a of the fitting portion 31 is larger than the diameter of the inner peripheral surface 41b of the fitting portion 41, and the outer peripheral surface 31a of the fitting portion 31 and the inner peripheral surface 41b of the fitting portion 41 are adapted to be pressed against each other in the radial direction. Note that the diameter of the outer peripheral surface 31a of the fitting portion 31 may be the same as the diameter of the inner peripheral surface 41b of the fitting portion 41, or may be smaller than the diameter of the inner peripheral surface 41b of the fitting portion 41.

[0041] Also, as shown in FIG. 3, in a state where the fitting portion 31 of the inner holding member 30 and the fitting portion 41 of the outer holding member 40 are fitted to each other, the side surface 32a of the holding portion 32 of the inner holding member 30 and the side surface 42b of the holding portion 42 of the outer holding member 40 are adapted to have portions facing each other in the axial direction of the axis x. In the illustrated example, in a state where the fitting portion 31 and the fitting portion 41 are fitted to each other, the entire or substantially the entire side surface 32a of the holding portion 32 and a part of the side surface 42b of the holding portion 42 are adapted to face each other in the axial direction of the axis x. That is, the diameter of the end 32c of the holding portion 32 is larger than the diameter of the end 42c of the holding portion 42, and the end 32c of the holding portion 32 is located on the outer peripheral side in the radial direction with respect to the end 42c of the holding portion 42. Note that the diameter of the end 32c of the holding portion 32 and the diameter of the end 42c of the holding portion 42 may be the same. Also, the diameter of the end 32c of the holding portion 32 may be smaller than the diameter of the end 42c of the holding portion 42, and the end 32c of the holding portion 32 may be located on the inner peripheral side in the radial direction with respect to the end 42c of the holding portion 42.

[0042] Also, as shown in FIG. 3, in a state where the fitting portion 31 of the inner holding member 30 and the fitting portion 41 of the outer holding member 40 are fitted to each other, the side surface 32a of the holding portion 32 of the inner holding member 30 and the side surface 42b of the holding portion 42 of the outer holding member 40 are opposed to the bases 23, 25 of the conductors 21, 22 in the axial direction of the axis x. In the illustrated example, in a state where the fitting portion 31 and the fitting portion 41 are fitted to each other, the entire or substantially entire side surface 32a of the holding portion 32 and the entire or substantially entire side surface 42b of the holding portion 42 are opposed to the bases 23, 25 of the conductors 21, 22 in the axial direction of the axis x.

[0043] Also, as shown in FIG. 3, the outer peripheral surface 31a of the fitting portion 31 of the inner holding member 30 and the inner peripheral surface 41b of the fitting portion 41 of the outer holding member 40 are in contact with each other, and in a state where the pressing portion 43 of the fitting portion 41 and the end 31c of the fitting portion 31 are in contact with each other in the axial direction of the axis x (hereinafter, also referred to as the "assembled state"), a gap is formed between the side surface 32a of the holding portion 32 and the side surface 42b of the holding portion 42. The width of this gap in the axial direction of the axis x, that is, the width in the axial direction of the axis x between the side surface 32a of the holding portion 32 and the side surface 42b of the holding portion 42 in the assembled state, is larger than the thickness of the bases 23, 25 of the conductors 21, 22, for example. Thereby, in the assembled state of the inner holding member 30 and the outer holding member 40, the bases 23, 25 of the conductors 21, 22 can be sandwiched between the holding portion 32 and the holding portion 42. Also, in the assembled state of the inner holding member 30 and the outer holding member 40, the bases 23, 25 of the conductors 21, 22 can be pressed and sandwiched between the holding portion 32 and the holding portion 42 in the axial direction of the axis x, and the conductors 21, 22 can be firmly sandwiched.

[0044] On the side surface 42b of the holding portion 42 of the outer holding member 40, as shown in FIGS. 2, 7, and 8 for example, convex portions 2a and 2b, which are portions protruding toward the front side, are provided at circumferential positions corresponding to the gaps 11 and 12 of the conductive member 3 respectively. Note that FIG. 7 is a cross-sectional view of the cross-section along line A-A of FIG. 2, and FIG. 8 is a cross-sectional view of the cross-section along line B-B of FIG. 2. In the conductive structure 1, the convex portion 2a is accommodated in the gap 11, and the convex portion 2b is accommodated in the gap 12. In the gap 11, the convex portion 2a is adapted to contact the end 21a of the conductor 21 and the end 22a of the conductor 22. In the gap 12, the convex portion 2b is adapted to contact the end 21b of the conductor 21 and the end 22b of the conductor 22. Note that in the gap 11, a gap may be formed between the convex portion 2a and the end 21a of the conductor 21. Also, in the gap 11, a gap may be formed between the convex portion 2a and the end 22a of the conductor 22. Similarly, in the gap 12, a gap may be formed between the convex portion 2b and the end 21b of the conductor 21. Also, in the gap 12, a gap may be formed between the convex portion 2b and the end 22b of the conductor 22. Note that the convex portions 2a and 2b may be provided so as to be accommodated in the gaps 11 and 12 respectively on the side surface 32a of the holding portion 32 of the inner holding member 30 instead of the side surface 42b of the holding portion 42 of the outer holding member 40. Also, the convex portions 2a and 2b may be provided not only on the side surface 42b of the holding portion 42 of the outer holding member 40 but also on the side surface 32a of the holding portion 32 of the inner holding member 30. Also, a plurality of the convex portions 2a may be provided. Also, a plurality of the convex portions 2b may be provided.

[0045] The inner holding member 30 is integrally formed from the same material, and the fitting portion 31 and the holding portion 32 are parts of the integrally formed inner holding member 30 and are integrally connected. Similarly, the outer holding member 40 is integrally formed from the same material, and the fitting portion 41 and the holding portion 42 are parts of the integrally formed outer holding member 40 and are integrally connected. The inner holding member 30 and the outer holding member 40 are made of a conductive metal, but may be integrally formed from other conductive materials.

[0046] Each component member of the conductive structure 1 has the above-described configuration, is assembled into an assembled state, and becomes the conductive structure 1 as shown in FIG. 3. In the conductive structure 1, the fitting portion 31 of the inner holding member 30 is fitted into the fitting portion 41 of the outer holding member 40, and the fitting portion 31 of the inner holding member 30 is pressed by the pressing portion 43 of the fitting portion 41 of the outer holding member 40 toward the back side, which is the side opposite to the front side. Further, the conductors 21 and 22 are sandwiched between the holding portion 32 of the inner holding member 30 and the holding portion 42 of the outer holding member 40. The conductors 21 and 22 are held by the inner holding member 30 and the outer holding member 40 on the outer peripheral side. In this way, the inner holding member 30 is fixed to the outer holding member 40, and the conductors 21 and 22 are fixed between the inner holding member 30 and the outer holding member 40. Further, the conductors 21 and 22 are attached to the inner holding member 30 and the outer holding member 40 such that the respective contact portions 24 and 26 protrude to the front side. Note that the conductors 21 and 22 may be attached to the inner holding member 30 and the outer holding member 40 such that the respective contact portions 24 and 26 protrude to the back side.

[0047] Before reaching the assembled state as shown in FIG. 3, the fitting portion 41 of the outer holding member 40 may not have the pressing portion 43. For example, the conductive member 3 may be attached to the outer holding member 40 in which the pressing portion 43 is not formed on the fitting portion 41, and then, after the fitting portion 31 of the inner holding member 30 is attached to the fitting portion 41 of the outer holding member 40, the pressing portion 43 may be formed on the fitting portion 41. That is, by forming the pressing portion 43, the fitting portion 31 and the fitting portion 41 are caulked, and the end 31c of the fitting portion 31 is pressed toward the back side in the axial direction x by the pressing portion 43, so that the conductive member 3, the inner holding member 30, and the outer holding member 40 may be brought into the assembled state as shown in FIG. 3.

[0048] Also, in the assembled state shown in FIG. 3, the convex portions 2a and 2b formed on the holding portion 42 of the outer holding member 40 are respectively received in the gaps 11 and 12 of the conductive member 3 and are in contact with the ends 21a and 21b of the conductor 21 and the ends 22a and 22b of the conductor 22.

[0049] Next, the operation of the conductive structure 1 will be described. FIG. 9 is a conceptual diagram for showing an example of an application target of the conductive structure 1. FIG. 10 is a cross-sectional view showing an example of the usage state of the conductive structure 1 in the application target shown in FIG. 9. As an example, the conductive structure 1 is applied to the drive device 100 of a battery electric vehicle (BEV) as shown in FIG. 9. The drive device 100 has, for example, an electric motor 101, a speed reducer 102, an inverter 103 for controlling the electric motor 101, and a battery 104 as a power source, as shown in FIG. 9. In the electric motor 101, the shaft 110 is rotatably supported by a bearing 112 supported in the housing 111, and also passes out of the housing 111 through the shaft hole 113 of the housing 111. The shaft 110 of the electric motor 101 enters the housing 120 of the speed reducer 102 through the shaft hole 124 of the housing 120 of the speed reducer 102, and is rotatably supported by a bearing 123 supported in the housing 120. Further, the shaft 110 is connected to the reduction gear stage 121 in the housing 120. The speed reducer 102 is provided with a shaft 122 that outputs a rotational driving force reduced by the reduction gear stage 121. The shaft 122 is rotatably supported by a bearing 123 supported in the housing 120, and is also connected to the wheel 105 so as to be able to transmit a rotational driving force to the wheel 105. An oil seal 125 for sealing the gap between the shaft hole 124 and the shaft 110 of the electric motor 101 is attached to the shaft hole 124 of the housing 120 of the speed reducer 102. An oil seal 127 for sealing the gap between the shaft hole 126 and the shaft 122 is attached to the shaft hole 126 of the housing 120 through which the shaft 122 of the speed reducer 102 passes. Note that the shaft 110 and the housing 111 of the electric motor 101 are made of metal, and the housing 120 and the shaft 122 of the speed reducer 102 are made of metal.

[0050] As an example, the conductive structure 1 is provided between the housing 111 of the electric motor 101 and the shaft 110 and comes into a use state. Specifically, as shown in FIG. 10, the fitting portion 41 of the outer holding member 40 of the holding member 2 is fitted into the shaft hole 113 of the housing 111, the conductive structure 1 is fixed to the shaft hole 113, and the shaft 110 is inserted into the conductive member 3, so that the conductive structure 1 comes into a use state. In the use state, the inner peripheral ends 24c and 26c of the conductors 21 and 22 of the conductive member 3 are in contact with the outer peripheral surface 110a of the shaft 110. Further, the holding member 2 (the inner holding member 30 and the outer holding member 40) to which the conductive member 3 is attached is made of a conductive metal and is in contact with the inner peripheral surface 113a of the shaft hole 113 of the housing 111. Thus, the conductive member 3 and the holding member 2 form an electric conduction path for flowing electricity between the shaft 110 and the housing 111 of the electric motor 101 in the use state.

[0051] Further, the conductive structure 1 may be provided between the housing 120 of the speed reducer 102 and the shaft 110. Specifically, as shown in FIG. 9, the conductive structure 1 may be provided in the gap between the shaft hole 124 of the housing 120 and the shaft 110 outside the oil seal 125. Also in this case, similar to the conductive structure 1 attached to the electric motor 101, the conductive member 3 and the holding member 2 of the conductive structure 1 form an electric conduction path for flowing electricity between the shaft 110 of the electric motor 101 and the housing 120 of the speed reducer 102. Similarly, the conductive structure 1 may be provided in the gap between the shaft hole 126 of the housing 120 and the shaft 122 outside the oil seal 127.

[0052] Note that the above-described drive device 100 is an example of the application target of the conductive structure 1, and the application target of the conductive structure 1 is not limited thereto. The conductive structure 1 is used, for example, in drive devices of electric vehicles (EVs) such as hybrid vehicles (HV), fuel cell vehicles (FCV), etc., in addition to battery electric vehicles (BEV). In vehicles equipped with an electric motor such as an electric vehicle (EV), electromagnetic wave noise may be generated by an induced current or the like generated from the motor. Also, electromagnetic wave noise may be generated by the on-off operation of an inverter for controlling the current supplied to an electric motor such as an electric motor, or by the induced voltage or the like of the electric motor itself. As described above, the conductive structure 1 forms a conductive path and allows the electromagnetic wave noise transmitted to the shaft 110 to flow into the housings 111 and 120. This can prevent communication failures and malfunctions from occurring in electronic devices, and can prevent electrolytic corrosion from occurring in metal parts such as bearings.

[0053] The conductors 21 and 22 of the conductive member 3 that contact the shaft 110 are made of PTFE and have high heat resistance and wear resistance. Therefore, in order to suppress wear and sagging of the conductors 21 and 22, it is not necessary to provide a lubricant having conductivity between the conductors 21 and 22 and the shaft 110. For this reason, there is no lubricant that can become the resistance of the conductive path in the conductive path between the shaft 110 and the housings 111 and 120, and it is possible to suppress a decrease in the conductive performance of the conductive structure 1 in the use state.

[0054] Also, in the conductive member 3, the conductors 21 and 22 are arranged annularly with gaps 11 and 12 therebetween. Therefore, even if an external force is applied to the conductors 21 and 22 due to the rotation of the shaft 110 in the use state, the conductors 21 and 22 can escape into the gaps 11 and 12, and it is possible to suppress the occurrence of deformation or contact with the shaft 110 that causes stress concentration in the conductors 21 and 22. Thereby, wear and sagging of the conductors 21 and 22 can be suppressed. Also in this regard, the conductive structure 1 can be made such that it is not necessary to provide a lubricant having conductivity between the conductors 21 and 22 and the shaft 110.

[0055] Further, the conductive structure 1 can be attached around the shaft 110 by fitting the holding member 2 into the shaft hole 113 of the housing 111. Thus, for attaching the conductive structure 1, only an annular space surrounding the outer peripheral surface 110a of the shaft 110 is required. If there is a space for attaching the conductive structure 1 between the outer peripheral surface 110a of the shaft 110 and the inner peripheral surface 113a of the shaft hole 113, the conductive structure 1 can be attached to the shaft holes 113, 124, so there is no need to additionally provide a space for attaching the conductive structure 1 to the housing 111. Further, even when there is no space for attaching the conductive structure 1 between the outer peripheral surface 110a of the shaft 110 and the inner peripheral surface 113a of the shaft hole 113, since the cross-section of the conductive structure 1 is not large, only a small annular space needs to be provided on the inner peripheral surface 113a of the shaft hole 113 for attaching the conductive structure 1. Thus, the conductive structure 1 can reduce the space for attaching the conductive structure 1 and enable space saving.

[0056] Further, in the conductive member 3, the conductors 21, 22 are arranged annularly with gaps 11, 12 therebetween. Therefore, when fixing the conductive member 3 to the holding member 2, the conductors 21, 22 can escape into the gaps 11, 12. Thereby, when fixing the conductive member 3 to the holding member 2, it is possible to suppress the occurrence of deformation such as wrinkles in the conductors 21, 22.

[0057] Also, intermediate products of the conductors 21, 22 formed into the shapes of the conductors 21, 22 can be made by cutting out a plurality from a single sheet-like material. Therefore, the conductors 21, 22 are manufactured with good yield and efficiency.

[0058] Further, in the assembled state shown in FIG. 3, the convex portions 2a, 2b formed on the holding portion 42 of the outer holding member 40 are respectively received in the gaps 11, 12 of the conductive member 3 and are in contact with the ends 21a, 21b of the conductor 21 and the ends 22a, 22b of the conductor 22. Therefore, due to the rotation of the shaft 110, the conductors 21, 22 do not rotate with respect to the holding member 2.

[0059] As described above, the conductive structure 1 according to the first embodiment of the present invention can suppress a decrease in conductive performance in a use state while enabling space saving.

[0060] Next, a modified example of the above-described conductive member 3 will be described. FIG. 11 is a front view of a conductive member 3A according to a modified example of the conductive member 3. As shown in FIG. 11, the conductive member 3A has one conductor 20 and one gap 10. The conductive member 3A has no one of the gaps 11 or 12 of the conductive member 3, and the conductor 21 or the conductor 22 also extends to one part of the gap 11 or the gap 12, and the conductor 21 and the conductor 22 are connected at one part of the gap 11 or the gap 12 to form one conductor 20. The conductor 20 of the conductive member 3A according to the modified example extends, for example, on a circle or a substantially circular shape centered or substantially centered on the axis x as shown in FIG. 11, and the end 20a and the end 20b face each other in the circumferential direction, specifically, for example, they face each other in a direction orthogonal to the axis x. The cross-sectional shape of the conductor 20 is the cross-sectional shape of the conductor 21. Note that the conductive member 3 may have three or more gaps 10 and three or more conductors 20. Also in this case, the plurality of gaps 10 and the plurality of conductors 20 are connected in a ring shape.

[0061] Next, the conductive structure 4 according to the second embodiment of the present invention will be described. FIG. 12 is a perspective view showing a schematic configuration of the conductive structure 4, and FIG. 13 is a cross-sectional perspective view of a part of the conductive structure 4 shown in FIG. 12 cut. Further, FIG. 14 is a front view of the conductive structure 4 shown in FIG. 11, and FIG. 15 is a cross-sectional view showing one side with respect to the axis x of a cross-section by a plane including the axis x of the conductive structure 4. The conductive structure 4 according to the present embodiment is different from the above-described conductive structure 1 mainly in that it has a spring member 50. Hereinafter, for the configuration of the conductive structure 4, the same components as those of the above-described conductive structure 1 or components having the same functions will be denoted by the same reference numerals and their description will be omitted, and different configurations will be described.

[0062] As described above, the conductive structure 4 has a spring member 50. As shown in FIGS. 11 to 15, the spring member 50 is an annular spring member around the axis x and is configured to generate an elastic force in the direction toward the axis x. Further, the spring member 50 is provided so as to be arranged in parallel with the conductive member 3 in the direction of the axis x. Note that the direction toward the axis x is not limited to the direction toward the inner peripheral side in the radial direction, and any direction having a component in the direction toward the inner peripheral side in the radial direction may be used. Specifically, the spring member 50 is an annular leaf spring and is configured to generate an elastic force for supporting the contact portions 24 and 26 so that the contact portions 24 and 26 of the conductors 21 and 22 of the conductive member 3 contact the outer peripheral surface 110a of the shaft 110 (see FIG. 10). As shown in FIG. 15, for example, the spring member 50 has a shape along the side surfaces 23a and 24a and the side surfaces 25a and 26a of the conductors 21 and 22, respectively. Further, as shown in FIG. 15, the spring member 50 is sandwiched between the holding portion 32 of the inner holding member 30 and the bases 23 and 25 of the conductors 21 and 22 and is fixed in the conductive structure 4. The conductive structure 4 is thus capable of holding the spring member 50. Specifically, in the assembled state of the inner holding member 30 and the outer holding member 40, the distance in the direction of the axis x between the holding portion 32 and the holding portion 42 is set so that the base 23 of the conductor 21 and the base 51 of the spring member 50 can be pressed and sandwiched in the direction of the axis x, and is also set so that the base 25 of the conductor 22 can be pressed and sandwiched in the direction of the axis x.

[0063] As shown in FIGS. 14 and 15 for example, the spring member 50 has a base portion 51 and an elastic portion 52. The base portion 51 is sandwiched between the holding portion 32 of the inner holding member 30 and the base portions 23 and 25 of the conductors 21 and 22 respectively. The elastic portion 52 is a portion that applies an elastic force toward the axis x to the contact portions 24 and 26 of the conductors 21 and 22 respectively, and is adapted to contact the side surfaces 24a and 26a of the contact portions 24 and 26 of the conductors 21 and 22 respectively. The elastic portion 52 extends along, for example, a cylindrical surface whose diameter decreases as it goes toward the front side in the direction of the axis x. The thickness of the spring member 50 is set according to, for example, the elastic force to be applied to the contact portions 24 and 26 of the conductors 21 and 22 respectively. Specifically, the spring member 50 is, for example, a leaf spring provided with a plurality of spring pieces protruding toward the inner peripheral side around the axis x as shown in FIGS. 13 and 14. The specific form of the spring member 50 may be other forms. Also, the spring member 50 may not extend continuously in an endless annular shape, but may extend in an end-ring shape, or may be a structure in which a plurality of spring members extending in an arc shape are arranged intermittently in an annular shape. For example, as shown in the drawing, the spring member 50 may not be in an endless annular shape, but may be two spring members extending on an arc corresponding to the conductors 21 and 22 respectively.

[0064] In the conductive structure 4, as described above, an elastic force toward the axis x is generated with respect to the contact portions 24 and 26 of the conductors 21 and 22 of the conductive member 3 respectively. For this reason, the conductors 21 and 22 are supported by the spring member 50 so as to contact the outer peripheral surface 110a of the shaft 110. Thereby, it is suppressed that the conductors 21 and 22 do not contact the shaft 110 due to weakening or deformation of the conductors 21 and 22 caused by changes over time.

[0065] The conductive structure 4 is also used in the same manner as the above-described conductive structure 1 to form a conductive path. Also, similar to the conductive structure 1, the conductive structure 4 can eliminate the need for a lubricant and can suppress a decrease in the conductive performance of the conductive structure 1 in the use state. Further, the conductive structure 4 can also eliminate or reduce the space where the conductive structure 4 is attached, enabling space saving. Also, even in the conductive structure 4, when fixing the conductive member 3 to the holding member 2, it is possible to suppress deformation such as wrinkles in the conductors 21 and 22. Also, the conductors 21 and 22 of the conductive structure 4 are also manufactured with good yield and efficiency. Also, even in the conductive structure 4, due to the rotation of the shaft 110, the conductors 21 and 22 do not rotate with respect to the holding member 2.

[0066] As described above, the conductive structure 4 according to the second embodiment of the present invention can suppress a decrease in conductive performance in the use state while enabling space saving.

[0067] Next, a conductive sealing device 5 according to the first embodiment of the present invention will be described. FIG. 16 is a cross-sectional view showing one side with respect to the axis x of a cross-section by a plane including the axis x of the conductive sealing device 5, showing a schematic configuration of the conductive sealing device 5. The conductive sealing device 5 is a sealing device for achieving sealing between a shaft of an application target and a hole through which the shaft passes, and is also a conductive structure for forming a conductive path between the shaft and the hole through which the shaft passes.

[0068] As shown in FIG. 16, the conductive sealing device 5 includes a reinforcing ring 60 which is an annular member around the axis x, an elastic body portion 70 formed of an annular elastic body attached to the reinforcing ring 60, and a conductive structure 6 which is annular around the axis x. The elastic body portion 70 has a seal lip 71 that contacts the shaft. The conductive structure 6 has a holding member 7 which is an annular member around the axis x and a conductive member 3 (see FIG. 4) which is an annular member around the axis x. The conductive member 3 has at least one gap 10 provided so as to extend in the radial direction and at least one conductor 20 having conductivity and extending around the axis x. The holding member 45 is attached to the elastic body portion 70 and holds the conductor 20 between the elastic body portion 70. The conductor 20 has a pair of ends 20a in the direction around the axis x, and the gap 10 is continuous with the ends 20a, 20b of the conductor 20. Hereinafter, the configuration of the conductive sealing device 5 will be specifically described.

[0069] As shown in FIG. 16, the conductive sealing device 5 has, for example, a reinforcing ring 60 and an elastic body portion 70 similar to a known oil seal. The reinforcing ring 60 has a cylindrical portion 61 and an annular portion 62. Further, the elastic body portion 70 has, in addition to the seal lip 71, a base portion 72, a gasket portion 73, and a cover portion 74. The seal lip 71 extends from the base portion 72 toward the object to be sealed. The gasket portion 73 is a portion that covers the cylindrical portion 61 of the reinforcing ring 60 from the outer peripheral side and is a portion that is press-fitted into the hole of the application target. The outer peripheral surface 73a of the gasket portion 73 has a diameter such that it is pressed against the hole of the application target. The cover portion 74 is a portion that covers the annular portion 62 of the reinforcing ring 60 from the side opposite to the object to be sealed.

[0070] As shown in FIG. 16, a fitting surface 75, which is an annular surface facing the outer peripheral side, is formed at the end portion on the outer peripheral side (outer peripheral end portion 74a) of the cover portion 74. The fitting surface 75 is, for example, a cylindrical surface extending along a cylindrical surface having the axis x as the central axis. The fitting surface 75 is, for example, a cylindrical surface extending along a cylindrical surface having the axis x as the central axis. Specifically, the fitting surface 75 is, for example, a cylindrical surface or a substantially cylindrical surface having the axis x as the central axis or a substantially central axis. As shown in FIG. 16, for example, the fitting surface 75 is located on the outer peripheral side relative to other portions of the outer peripheral end portion 74a, and an annular recess 76 that is recessed inward is formed between the fitting surface 75 and the gasket portion 73. The fitting surface 75 of the cover portion 74 is located on the inner peripheral side in the radial direction relative to the outer peripheral surface 73a of the gasket portion 73.

[0071] Further, the cover portion 74 has a holding surface 77, which is an annular surface facing the side opposite to the object to be sealed. The holding surface 77 is, for example, a surface extending along a plane orthogonal to the axis x. Specifically, the holding surface 77 is, for example, a surface extending on a surface parallel or substantially parallel to a plane orthogonal to the axis x.

[0072] The conductive structure 6 has a holding member 45 similar to the outer holding member 40 of the holding member 2 of the above-described conductive structure 1, and a conductive member 3 (see FIG. 4) of the above-described conductive structure 1. The holding member 45 is made of the same conductive material as the outer holding member 40. As shown in FIG. 16, the holding member 45 has, for example, a fitting portion 46 which is an annular portion around the axis x, and a holding portion 47 which is an annular portion around the axis x. The fitting portion 46 is a cylindrical portion extending along the axis x, and the holding portion 47 is an annular portion extending inward from the end of the fitting portion 46. As shown in FIG. 16, the fitting portion 46 has, for example, an outer peripheral surface 46a and an inner peripheral surface 46b which are surfaces facing away from each other in the direction of the axis x, and the cross-sectional shape is substantially rectangular. The outer peripheral surface 46a is an annular surface facing the outer peripheral side, and the inner peripheral surface 46b is an annular surface facing the inner peripheral side. The inner peripheral surface 46b is a cylindrical surface extending along the axis x, and is, for example, a cylindrical surface or a substantially cylindrical surface having the axis x as the central axis or the substantially central axis. Also, as shown in FIG. 16, the holding portion 47 has, for example, side surfaces 47a and 47b which are surfaces facing away from each other in the direction of the axis x, and the cross-sectional shape is rectangular or substantially rectangular. The side surface 47b connected to the inner peripheral surface 46b of the fitting portion 46 extends along a plane orthogonal to the axis x, and extends, for example, on a surface parallel or substantially parallel to the plane orthogonal to the axis x.

[0073] The fitting portion 46 of the holding member 45 is capable of fitting into the outer peripheral end portion 74a of the cover portion 74 of the elastic body portion 70. Specifically, for example, the diameter of the inner peripheral surface 46b of the fitting portion 46 is smaller than the diameter of the fitting surface 75 of the outer peripheral end portion 74a of the cover portion 74. Thereby, the cover portion 74 of the elastic body portion 70 is press-fitted into the fitting portion 46 of the holding member 45 so that the holding member 45 is fixed to the elastic body portion 70.

[0074] As shown in FIG. 16, the conductive member 3 is held between the holding portion 47 of the holding member 45 and the holding surface 77 of the cover portion 74 of the elastic body portion 70. Specifically, the side surfaces 47b of the holding portion 47 are in contact with the side surfaces 23a, 25a of the bases 23, 25 of the conductors 21, 22 of the conductive member 3, respectively, pressing the bases 23, 25 against the holding surface 77 of the cover portion 74. As described above, the fitting portion 46 of the holding member 45 is fitted to the outer peripheral end portion 74a of the cover portion 74 of the elastic body portion 70, and the holding member 45 is fixed to the elastic body portion 70 in a state where the holding portion 47 presses the bases 23, 25 against the holding surface 77 of the cover portion 74. Note that a convex portion 48 to be accommodated in the concave portion 76 of the cover portion 74 may be provided at the end portion 46c of the fitting portion 46 of the holding member 45 (see FIG. 16). As described above, when the fitting portion 46 of the holding member 45 is fitted to the outer peripheral end portion 74a of the cover portion 74 of the elastic body portion 70, by allowing the convex portion 48 to be accommodated in the concave portion 76, the holding member 45 can be more firmly fixed to the elastic body portion 70 in a state where the holding portion 47 presses the bases 23, 25 against the holding surface 77 of the cover portion 74.

[0075] In the conductive sealing device 5, the contact portions 24, 26 of the conductors 21, 22 are configured to contact the outer peripheral surface of the axis to be applied. Further, as shown in FIG. 16, the contact portions 24, 26 of the conductors 21, 22 protrude to the side opposite to the sealing target side.

[0076] In addition, on the side surface 47b of the holding portion 47 of the holding member 45, convex portions 2a and 2b of the above-described conductive structure 1 are similarly provided. In the conductive sealing device 5, the convex portions 2a and 2b are respectively accommodated in the gaps 11 and 12 of the conductive member 3. Further, the convex portion 2a is in contact with the end 21a of the conductor 21 and the end 22a of the conductor 22, and the convex portion 2b is in contact with the end 21b of the conductor 21 and the end 22b of the conductor 22. Note that in the gap 11, a gap may be formed between the convex portion 2a and the end 21a of the conductor 21. Also, in the gap 11, a gap may be formed between the convex portion 2a and the end 22a of the conductor 22. Similarly, in the gap 12, a gap may be formed between the convex portion 2b and the end 21b of the conductor 21. Also, in the gap 12, a gap may be formed between the convex portion 2b and the end 22b of the conductor 22. Note that the convex portions 2a and 2b may be provided so as to be respectively accommodated in the gaps 11 and 12 on the holding surface 77 of the cover portion 74 of the elastic body portion 70 instead of the side surface 47b of the holding portion 47 of the holding member 45. Also, the convex portions 2a and 2b may be provided not only on the side surface 47b of the holding portion 47 of the holding member 45 but also on the holding surface 77 of the cover portion 74 of the elastic body portion 70. Also, a plurality of convex portions 2a may be provided. Also, a plurality of convex portions 2b may be provided.

[0077] Each component of the conductive sealing device 5 has the above-described configuration, is assembled into an assembled state, and becomes the conductive sealing device 5 as shown in FIG. 16. In the conductive sealing device 5, the fitting portion 46 of the holding member 45 is fitted to the outer peripheral end portion 74a of the cover portion 74 of the elastic body portion 70, and the conductors 21 and 22 are sandwiched between the holding portion 47 of the holding member 45 and the holding surface 77 of the cover portion 74 of the elastic body portion 70. In this way, the holding member 45 is fixed to the elastic body portion 70, and the conductors 21 and 22 are fixed between the holding member 45 and the elastic body portion 70. Also, the conductors 21 and 22 are attached between the holding member 45 and the elastic body portion 70 such that the respective contact portions 24 and 26 protrude to the side opposite to the seal lip 71 side. Note that the conductors 21 and 22 may be attached such that the respective contact portions 24 and 26 protrude to the seal lip 71 side, for example, if there is no interference with the elastic body portion 70.

[0078] FIG. 17 is a conceptual diagram for showing an example of an application target of the conductive sealing device 5. FIG. 18 is a cross-sectional view showing an example of a usage state of the conductive sealing device 5 in the application target shown in FIG. 17. As an example, the conductive sealing device 5 is applied to a drive device 200 of a battery electric vehicle (BEV) as shown in FIG. 17. The drive device 200 has the same configuration as the above-described drive device 100 (see FIGS. 9 and 10), but is different in that the conductive structure 1 is not attached to the drive device 100. Further, instead of the oil seals 125 and 127 of the drive device 100, the conductive sealing device 5 is attached to the drive device 200. As an example, the conductive sealing device 5 is provided between the housing 120 of the speed reducer 102 and the shafts 110 and 122 to be in a usage state. Specifically, the gasket portion 73 of the elastic body portion 70 is fitted into the shaft holes 124 and 126 of the housing 120, and the conductive sealing device 5 is fixed to the shaft holes 124 and 126. Further, the shafts 110 and 122 are inserted into the seal lip 71 and the conductive member 3, and the conductive sealing device 5 is in a usage state. In the usage state, the seal lip 71 contacts the outer peripheral surfaces 110a and 122a of the shafts 110 and 122, and the object to be sealed is sealed. Further, in the usage state, the inner peripheral ends 24c and 26c of the conductors 21 and 22 of the conductive member 3 contact the outer peripheral surfaces 110a and 122a of the shafts 110 and 122. Further, the holding member 45 to which the conductive member 3 is attached is made of a conductive metal and contacts the inner peripheral surfaces 124a and 126a of the shaft holes 124 and 126 of the housing 120. Thus, the conductive member 3 and the holding member 45 form a conductive path for flowing electricity between the shafts 110 and 122 and the housing 120 in the usage state.

[0079] Incidentally, the above-described drive device 200 is an example of the application target of the conductive sealing device 5, and the application target of the conductive sealing device 5 is not limited thereto. The conductive sealing device 5 is used, for example, in drive devices of electric vehicles (EVs) such as hybrid vehicles (HV), fuel cell vehicles (FCV), etc., in addition to battery electric vehicles (BEV). In a vehicle equipped with an electric motor such as an electric vehicle (EV), electromagnetic wave noise may be generated by an induced current or the like generated from the motor. Also, electromagnetic wave noise may be generated by the on-off operation of an inverter for controlling the current supplied to an electric motor such as an electric motor, or by the induced voltage or the like of the electric motor itself. As described above, the conductive sealing device 5 forms a conductive path and allows the electromagnetic wave noise transmitted to the shafts 110 and 122 to flow into the housing 120. This can prevent communication failures and malfunctions from occurring in electronic devices, and can prevent electrolytic corrosion from occurring in metal parts such as bearings.

[0080] The conductive structure 6 of the conductive sealing device 5 is also used in the same manner as the above-described conductive structure 1 to form a conductive path. Also, like the conductive structure 1, the conductive structure 6 can eliminate the need for a lubricant and can suppress a decrease in the conductive performance of the conductive structure 6 in the use state. Also, in the conductive member 3 of the conductive sealing device 5, even if an external force is applied to the conductors 21 and 22 due to the rotation of the shafts 110 and 122, it is possible to suppress the occurrence of deformation such that stress concentration occurs and contact with the shafts 110 and 122 in the conductors 21 and 22. Also in this regard, the conductive sealing device 5, like the conductive structure, can eliminate the need to provide a lubricant having conductivity between the conductors 21 and 22 and the shafts 110 and 122. Also, since the conductive structure 6 is attached between the radial widths of the sealing device, it does not require a space for attaching the conductive structure 6, and space saving can be achieved. Also, in the conductive sealing device 5, when fixing the conductive member 3 between the holding member 45 and the elastic body portion 70, it is possible to suppress the occurrence of deformation such as wrinkles in the conductors 21 and 22. Also, the conductors 21 and 22 of the conductive structure 6 are manufactured with good yield and efficiency. Also, in the conductive sealing device 5, the conductors 21 and 22 do not rotate with respect to the holding member 45 and the elastic body portion 70 due to the rotation of the shafts 110 and 122.

[0081] Further, the conductive member 3 of the conductive structure 6 has gaps 11 and 12 between the conductor 21 and the conductor 22. Since the gaps 11 and 12 are through holes penetrating the conductive member 3 in the axial direction of the axis x, in the use state of the conductive sealing device 5, a through hole penetrating the conductive member 3 in the axial direction of the axis x is formed between the shafts 110 and 122 and the shaft holes 124 and 126. As shown in FIG. 16, the seal lip 71 has a plurality of convex portions 71a extending in a spiral shape, and the convex portions 71a exhibit a pumping action. Therefore, in the use state, the seal lip 71 draws air into the sealing target side. Since the conductive member 3 forms a through hole penetrating the conductive member 3 in the axial direction of the axis x between the shafts 110 and 122 and the shaft holes 124 and 126 as described above, even if air is drawn into the sealing target side by the pumping action of the seal lip 71, the space between the conductors 21 and 22 of the conductive member 3 and the seal lip 71 does not become a negative pressure state. Thereby, wear of the seal lip 71 and an increase in sliding resistance can be prevented, and wear of the conductors 21 and 22 of the conductive member 3 and an increase in sliding resistance can be prevented.

[0082] As described above, the conductive sealing device 5 according to the first embodiment of the present invention can suppress a decrease in conductive performance in the use state while enabling a space.

[0083] Note that, also in the conductive structure 6 of the conductive sealing device 5, various modifications can be made as in the case of the conductive structure 1.

[0084] As described above, the present invention has been described through the above embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. It is clear from the description of the claims that forms with such changes or improvements can also be included in the technical scope of the present invention.

[0085] The embodiments described above are for facilitating the understanding of the present invention and are not for limiting and interpreting the present invention. Also, the above-described embodiments do not limit the objects to which the present invention is applied, and the present invention can include any object as its application target. Each component included in the above embodiments, as well as its arrangement, material, conditions, shape, size, etc. are not limited to those illustrated and can be changed as appropriate. For example, the present invention includes differences that occur in implementation such as manufacturing tolerances. Also, within a technically non-contradictory range, components shown in different embodiments can be partially substituted or combined with each other. Further, each configuration can be selectively combined as appropriate so as to achieve at least a part of the above-described problems and effects.

[0086] For example, the shape of the outer peripheral ends (ends 23c, 25c) of the conductive member 3 may not be a shape along a circle but a shape having a straight portion along a straight line. For example, as shown in FIG. 19, two pairs of straight portions, namely a pair of straight portions 3a and a pair of straight portions 3b, may be provided at the outer peripheral ends (ends 23c, 25c) of the conductive member 3. In this case, by providing configurations such as stepped portions or protrusions corresponding to this straight portion on the holding members 2, 7 and the cover portion 74 of the elastic body portion 70, rotation of the conductors 21, 22 can be prevented. For example, as shown in FIG. 20, a concave portion 77a is formed on the holding surface 77 of the cover portion 74 of the elastic body portion 70 of the conductive sealing device 5, which depicts a contour corresponding to the contour of the outer peripheral end of the conductive member 3 as shown in FIG. 19, and the conductive member 3 may be accommodated in this concave portion 77a. In this case, the convex portions 2a, 2b do not need to be provided, and even if the convex portions 2a, 2b are not provided, rotation of the conductors 21, 22 with respect to the holding member 45 and the elastic body portion 70 can be prevented by the rotation of the shaft 110. Also, the conductors 20 (conductors 21, 22) and the holding members 2, 7 and the elastic body portion 70 may be adhered using an adhesive. In this case, the adhesive is applied so as not to become a resistance in the conductive path. Also, in this case, an adhesive having conductivity is used.

Explanation of Reference Numerals

[0087] 1, 4, 6 conductive structures, 2, 7 holding members, 2a, 2b convex portions, 3, 3A conductive members, 3a, 3b straight portions, 5 conductive sealing devices, 10, 11, 12 gaps, 20, 21, 22 conductors, 20a, 20b, 21a, 21b, 22a, 22b ends, 23, 25 bases, 23a, 23b, 25a, 25b sides, 23c, 25c ends, 24, 26 contact portions, 24a, 24b, 26a, 26b sides, 24c, 26c inner peripheral ends, 30 inner holding member, 31 fitting portion, 31a outer peripheral surface, 31b inner peripheral surface, 31c end, 32 holding portion, 32a, 32b sides, 32c end, 40 outer holding member, 45 holding member, 41, 46 fitting portions, 41a, 46a outer peripheral surfaces, 41b, 46b inner peripheral surfaces, 42, 47 holding portions, 42a, 42b, 47a, 47b sides, 42c end, 43 pressing portion, 46c end portion, 48 convex portion, 50 spring member, 51 base, 52 elastic portion, 60 reinforcing ring, 61 cylindrical portion, 62 annular portion, 70 elastic body portion, 71 seal lip, 71a convex portion, 72 base, 73 gasket portion, 73a outer peripheral surface, 74 cover portion, 74a outer peripheral end portion, 75 fitting surface, 76 concave portion, 77 holding surface, 77a concave portion, 100, 200 drive devices, 101 electric motor, 102 speed reducer, 103 inverter, 104 battery, 105 wheel, 110, 122 shafts, 110a, 122a outer peripheral surfaces, 111, 120 housings, 121 speed reduction gear stage, 112, 123 bearings, 113, 124, 126 shaft holes, 113a, 124a, 126a inner peripheral surfaces, 125, 127 oil seals, x-axis line

Claims

[Claim 1] A retaining member which is an annular conductive member around the axis, The system comprises a conductive member which is an annular member around the aforementioned axis, The conductive member has a gap provided to extend in at least one radial direction and a conductive material having conductivity extending around at least one axis, The conductive member is held by the holding member, The conductor has a pair of ends in the direction of the axis, The gap is connected to the end of the conductor, Conductive structure.

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