Conductive structure and conductive sealing device

Abstract

Provided is an electrically conductive structure with which it is possible to suppress deterioration of conductive performance in a use state while saving space. The electrically conductive structure (1) comprises a holding member (2) that has annular electric conductivity around an axis x, and an electrically conductive member (3) that is annular around the axis (x). The electrically conductive member (3) has a gap (10) that is provided so as to extend in at least one radial direction, and an electrically conductive body (20) that is electrically conductive and extends around at least one axis x. The electrically conductive member (3) is held by the holding member (2). The electrically conductive body (20) has a pair of ends (20a, 20b) in the direction around the axis x. The gap (10) is continuous with the ends (20a, 20b) of the electrically conductive body (20).

Description

[Technical field]

[0001] The present invention relates to an electrically conductive structure and electrically conductive sealing device, and more particularly to an electrically conductive structure and electrically conductive sealing device for forming an electrically conductive path in a rotating shaft. [Background technology]

[0002] For example, in a vehicle equipped with an electric motor such as an electric vehicle (EV), electromagnetic noise may be generated by induced current generated by the motor. Such electromagnetic noise may cause communication failure in AM radios and other wireless communication devices. In addition, such electromagnetic noise may cause electrolytic corrosion in metal parts such as bearings. For this reason, efforts have been made to remove such electromagnetic noise, and conductive structures and conductive devices that form a conductive path in a rotating shaft have been proposed. For example, a technology has been disclosed in which an oil seal that seals the rotating shaft of a motor is made of conductive rubber, a conductive path is formed in the rotating shaft, and electromagnetic noise is released from the rotating shaft to a housing (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-244180 A Summary of the Invention [Problem to be solved by the invention]

[0004] A lubricant is used for the oil seal for lubrication, and an oil film is formed between the seal lip and the rotating shaft in a state of use. A conductive lubricant is used for the oil seal having conductive rubber 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 be a resistance to the current between the conductive seal lip and the rotating shaft. Therefore, even if 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 additional space in the mounting space of the oil seal. Thus, the conventional conductive structure and conductive device as described above can save space, but the conductive performance may decrease in a state of use. For this reason, a configuration that can suppress the decrease in conductive performance in a state of use while enabling space saving is required for the conventional conductive structure and conductive device.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a conductive structure and a conductive sealing device that enable space saving while suppressing a decrease in conductive performance during use. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the conductive structure of the present invention comprises a holding member which is a conductive member having an annular shape around an axis, and a conductive member which is a conductive member having an annular shape around the axis, the conductive member having at least one gap extending in a radial direction, and at least one conductive conductor extending around the axis, the conductive member being held by the holding member, the conductor having a pair of ends in a direction around the axis, and the gap being connected to the ends of the conductor.

[0007] In one embodiment of the conductive structure of 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 are opposed in a direction around the axis, and the gap is a gap between the opposing ends of the conductors.

[0008] In one embodiment of the conductive structure of 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 of the conductors 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 of the conductors face each other in the direction around the axis, one of the gaps is formed between the one end of the one conductor and the one end of the other conductor, and the other of the gaps is formed between the other end of the one conductor 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 at an outer periphery side.

[0010] In one aspect of the conductive structure of the present invention, a ring-shaped spring member is provided around the axis, the spring member is configured to generate an elastic force in a direction toward the axis, and the spring member is arranged next to the conductive member in the axial direction.

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

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

[0013] In order to achieve the above-mentioned object, the conductive sealing device of the present invention is a conductive sealing device for achieving a seal between a shaft and a hole through which the shaft passes, and comprises a reinforcing ring which is a ring-shaped member about an axis, an elastic body portion formed from an elastic body which is ring-shaped about the axis and attached to the reinforcing ring, and a conductive structure which is ring-shaped about the axis, the elastic body portion having a seal lip which contacts the shaft, the conductive structure having a retaining member which is a ring-shaped member about the axis, and a conductive member which is a ring-shaped member about the axis, the conductive member having at least one radially extending gap and at least one conductive conductor extending about the axis, the retaining member is attached to the elastic body portion and holds the conductor between itself and the elastic body portion, the conductor has a pair of ends in a direction about the axis, and the gap is connected to the end of the conductor.

[0014] In one embodiment of the conductive sealing device of 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 are opposed in a direction around the axis, and the gap is a gap between the opposing ends of the conductors.

[0015] In one embodiment of the conductive sealing device of 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 of the conductors 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 of the conductors face each other in the direction around the axis, one of the gaps is formed between the one end of the one conductor and the one end of the other conductor, and 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 protrusion that is received in the gap, and the protrusion protrudes in the axial direction.

[0017] In one embodiment of the conductive sealing device according to the present invention, the conductor is formed of conductive PTFE. Effect 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 during use while enabling space saving. [Brief description of the drawings]

[0019] [Figure 1] 1 is a perspective view showing a schematic configuration of a conductive structure according to a first embodiment of the present invention. [Diagram 2] 2 is a front view of the conductive structure shown in FIG. [Diagram 3] 2 is a cross-sectional view showing one side of the axis of the cross section taken along a plane including the axis of the conductive structure shown in FIG. 1. [Figure 4] 2 is a front view of a conductive member in the conductive structure shown in FIG. [Diagram 5] FIG. 11 is a cross-sectional view showing a modified example of the conductor. [Figure 6] FIG. 11 is a cross-sectional view showing a modified example of the conductor. [Figure 7] 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 8] 3 is a cross-sectional view taken along line BB in FIG. 2. [Figure 9] 2 is a conceptual diagram showing an example of an application target of the conductive structure shown in FIG. 1. FIG. [Figure 10] 10 is a cross-sectional view showing an example of a state in which the conductive structure shown in FIG. 1 is used in the application object shown in FIG. [Figure 11] FIG. 11 is a front view of a conductive member 3 according to a modified example. [Figure 12] FIG. 6 is a perspective view showing a schematic configuration of a conductive structure according to a second embodiment of the present invention. [Figure 13] 13 is a cross-sectional perspective view of a portion of the conductive structure shown in FIG. 12. FIG. [Figure 14] FIG. 13 is a front view of the conductive structure shown in FIG. [Figure 15] 13 is a cross-sectional view showing one side of the axis of the cross section taken along a plane including the axis of the conductive structure shown in FIG. 12. [Figure 16] 1 is a cross-sectional view showing a schematic configuration of a conductive sealing device according to a first embodiment of the present invention, the cross-sectional view being taken along a plane including an axis of the conductive sealing device, the cross-sectional view showing one side with respect to the axis. [Figure 17] FIG. 17 is a conceptual diagram showing an example of an application target of the conductive sealing device shown in FIG. 16. [Figure 18] 18 is a cross-sectional view showing an example of a state in which the conductive sealing device 5 shown in FIG. 16 is used in the application object shown in FIG. [Figure 19] FIG. 13 is a front view of a conductive member according to a modified example. [Figure 20] 20 is a cross-sectional view of a modified conductive sealing device to which the conductive member of FIG. 19 is attached. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that in the drawings, not all of the components are labeled with reference numerals, and some of the components may be omitted.

[0021] The conductive structure according to the embodiment of the present invention forms a conductive path in a rotating shaft, for example, between the shaft and a hole through which the shaft is inserted. However, the application of the conductive structure according to the embodiment of the present invention is not limited to this. Fig. 1 is a perspective view showing a schematic configuration of a conductive structure 1 according to a 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 of a cross section of the conductive structure 1 taken along a plane including the axis x with respect to the axis x.

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

[0023] The conductive member 3 has two gaps 10 and two conductors 20, as shown in, for example, Figs. 1 to 3. 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 are conductive and are formed from a conductive material. The material of the conductors 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, another conductive resin, conductive rubber, or a conductive fiber such as a nonwoven fabric.

[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, 12) and two conductors 20 (conductors 21, 22) in the conductive structure 1. As shown in FIG. 4, the conductor 21 has a pair of ends 21a, 21b as the pair of ends 20a, 20b, and the conductor 22 has a pair of ends 22a, 22b as the pair of ends 20a, 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). In addition, 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 side of gap 10 (gap 11) is formed between end 21a of conductor 21 and end 22a of conductor 22, and the other side of gap 10 (gap 12) is formed between end 21b of conductor 21 and end 22b of conductor 22.

[0025] 2 and 4, the conductors 21 and 22 are plate-like members extending along an arc about the axis x, for example, extending along an arc or an approximate arc centered or approximately centered on the axis x. Also, as shown in Fig. 3, the conductor 21 has a base 23 which is a portion extending along a plane, and a contact portion 24 which is a portion extending from the base 23 at an angle in the direction of the axis x.

[0026] As shown in Figs. 3 and 4, the base 23 is a plate-like portion, and has, for example, side surfaces 23a and 23b that are surfaces facing each other in the direction of the axis x. The side surface 23a extends along a plane perpendicular to the axis x, and for example, extends on a plane parallel or approximately parallel to the plane perpendicular to the axis x. Similarly, the side surface 23b extends along a plane perpendicular to the axis x, and for example, extends on a plane parallel or approximately parallel to the plane perpendicular to the axis x. The side surface 23a faces the front side (the right side in the direction of the axis x in Fig. 3). The side surface 23a and the side surface 23b extend so as to draw an arc or an approximately arc as shown in Fig. 4. In addition, the outer peripheral 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 from the end of the inner periphery of the base portion 23 toward the side (front side) where the side surface 23a of the base portion 23 faces. The contact portion 24 is a plate-like portion, and has, for example, side surfaces 24a and 24b that face each other. The contact portion 24 is shaped so that the diameter decreases toward the front side in the direction of the axis x. The contact portion 24 is formed so that the shape of a cross section (hereinafter, simply referred to as a "cross section") taken along a plane including the axis x is a shape along a circular arc, as shown in FIG. 3, for example. Specifically, for example, as shown in FIG. 3, in the cross section, the side surface 24a draws a convex circular arc or an approximate circular arc toward the inner periphery. Similarly, the side surface 24b draws a convex circular arc or an approximate circular arc toward the inner periphery. The side surface 24a is connected to the side surface 23a of the base portion 23, and the side surface 24b is connected to the side surface 23b of the base portion 23. Furthermore, the inner peripheral end (inner peripheral end 24c) of the contact portion 24 extends along a circle centered on the axis x, for example, on a circle or approximately on a circle centered or approximately centered on the axis x.

[0028] The contact portion 24 is configured such that, in a use state in which the conductive structure 1 is attached to an application target, the inner peripheral end of the contact portion 24 comes into contact with the outer peripheral surface of the shaft of the application target. Specifically, the diameter of the inner peripheral end 24c of the contact portion 24 is set corresponding to the diameter of the outer peripheral surface of the application target shaft, and is, for example, the same as or smaller than the diameter of the outer peripheral surface of the shaft. As shown in FIG. 3, for example, in the cross section, the conductor 21 has a uniform or approximately uniform thickness. Note that the thickness of the conductor 21 is the distance between the side surface 23a and the side surface 23b in the base portion 23, and is the distance between the side surface 24a and the side surface 24b in the contact portion 24. Note that the conductor 21 does not have to have a uniform thickness.

[0029] As shown in Figures 3 and 4, the conductor 21 extends in the circumferential direction so that the length is shorter than the semicircle of the circle along which the conductor 21 extends. In other words, the conductor 21 extends in the circumferential direction so that the ends 21a and 21b of the conductor 21 are not both located on a plane including the axis x or beyond a plane including the axis x. As shown in Figure 4, the ends 21a and 21b of the conductor 21 extend, for example, parallel or approximately parallel to the plane including the axis x and face each other in a direction perpendicular to the axis x. Note that the ends 21a and 21b of the conductor 21 do not have to extend parallel to the plane including the axis x.

[0030] The cross-sectional shape of the conductor 21 is not limited to the above-mentioned cross-sectional shape, and may be various cross-sectional shapes. For example, as shown in FIG. 5, the contact portion 24 of the conductor 21 may have a shape extending along a conical surface with the axis x as the central axis. Also, as shown in FIG. 6, the contact portion 24 of the conductor 21 may not be inclined with respect to the base portion 23, and the side surface 23a and the side surface 24a may be flush with each other, and the side surface 23b and the side surface 24b may be flush with each other. Also, the contact portion 24 of the conductor 21 may have a shape extending along another curved line in the cross section, or may have a shape extending along a line that is a combination of a curved line and a straight line.

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

[0032] 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 an approximate circle centered or approximately centered on the axis x. Specifically, for example, the conductors 21 and 22 are arranged so as to be symmetrical with respect to a plane including the axis x. In addition, the conductors 21 and 22 are arranged so that the inner circumferential end 24c of the contact portion 24 of the conductor 21 and the inner circumferential end 26c of the contact portion 26 of the conductor 22 are located on a circle or an approximate circle centered or approximately centered on the axis x. The end 21a of the conductor 21 and the end 22a of the conductor 22 face each other in a direction perpendicular 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 perpendicular to the axis x. As a result, 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 manner, the gap 11 is continuous between the end 21a of the conductor 21 and the end 22a of the conductor 22, and the gap 12 is continuous between the end 21b of the conductor 21 and the end 22b of the conductor 22.

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

[0034] 3, the inner holding member 30 has, for example, a fitting portion 31 which is an annular portion about the axis x, and a holding portion 32 which is an annular portion about 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 an end of the fitting portion 31 to the inner periphery side.

[0035] As shown in Fig. 3, the fitting portion 31 has, for example, an outer peripheral surface 31a and an inner peripheral surface 31b which are surfaces facing each other in a radial direction perpendicular to the axis x direction, and has a rectangular or approximately 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, for example, a cylindrical surface or an approximately cylindrical surface with the axis x as the central axis or approximately central axis. Similarly, the inner peripheral surface 31b is a cylindrical surface extending along the axis x, for example, a cylindrical surface or an approximately cylindrical surface with the axis x as the central axis or approximately central axis.

[0036] As shown in FIG. 3, the holding portion 32 has, for example, side surfaces 32a and 32b that are opposed to each other in the direction of the axis x, and has a rectangular or substantially rectangular cross-sectional shape. The side surface 32a extends along a plane perpendicular to the axis x, for example, on a plane parallel or substantially parallel to the plane perpendicular to the axis x. Similarly, the side surface 32b extends along a plane perpendicular to the axis x, for example, on a plane parallel or substantially parallel to the plane perpendicular 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] 3, the outer holding member 40 has, for example, a fitting portion 41 which is an annular portion about the axis x, and a holding portion 42 which is an annular portion about 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 an end of the fitting portion 41 to the inner periphery 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 which are surfaces facing each other in the direction of the axis x, and has a substantially rectangular cross-sectional shape. 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, for example, a cylindrical surface or a substantially cylindrical surface with the axis x as the central axis or the substantially central axis. Similarly, the inner peripheral surface 31b is a cylindrical surface extending along the axis x, for example, a cylindrical surface or a substantially cylindrical surface with the axis x as the central axis or the substantially central axis. Also, as shown in FIG. 3, a pressing portion 43 which is a protruding portion protruding to the inner peripheral side is formed at the end on the front side of the fitting portion 41. Specifically, the pressing portion 43 protrudes to the inner peripheral side from the inner peripheral surface 41b. The pressing portion 43 extends in an annular shape around the axis x, for example, as shown in FIGS. 1 and 3. The pressing portion 43 does not have to extend continuously in an annular shape around the axis x, but may extend discontinuously in an annular shape around the axis x. The pressing portion 43 may be formed, for example, by a series of protrusions extending in an arc shape along a circle centered on the axis x, which are arranged discontinuously.

[0039] As shown in FIG. 3, the holding portion 42 has, for example, side surfaces 42a and 42b that are opposed to each other in the direction of the axis x, and has a rectangular or substantially rectangular cross-sectional shape. The side surface 42a extends along a plane perpendicular to the axis x, for example, on a plane parallel or substantially parallel to the plane perpendicular to the axis x. Similarly, the side surface 42b extends along a plane perpendicular to the axis x, for example, on a plane parallel or substantially parallel to the plane perpendicular 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 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 in contact with 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 pressed against each other in the radial direction. 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] 3, when the fitting portion 31 of the inner holding member 30 and the fitting portion 41 of the outer holding member 40 are fitted together, 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 have portions that face each other in the direction of the axis x. In the illustrated example, when the fitting portion 31 and the fitting portion 41 are fitted together, the entire or substantially the entire side surface 32a of the holding portion 32 and a portion of the side surface 42b of the holding portion 42 face each other in the 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 periphery side in the radial direction than the end 42c of the holding portion 42. 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. In addition, the diameter of end 32c of holding portion 32 may be smaller than the diameter of end 42c of holding portion 42, and end 32c of holding portion 32 may be located radially inner than end 42c of holding portion 42.

[0042] 3, when the fitting portion 31 of the inner holding member 30 and the fitting portion 41 of the outer holding member 40 are fitted together, 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 face the bases 23, 25 of the conductors 21, 22, respectively, in the direction of the axis x. In the illustrated example, when the fitting portion 31 and the fitting portion 41 are fitted together, the entire or substantially the entire side surface 32a of the holding portion 32 and the entire or substantially the entire side surface 42b of the holding portion 42 face the bases 23, 25 of the conductors 21, 22, respectively, in the direction of the axis x.

[0043] 3, in a state where 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 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 axis x direction (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 axis x direction, that is, the width in the axis x direction 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, for example, larger than the thickness of the bases 23, 25 of the conductors 21, 22, respectively. As a result, 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, respectively. In addition, when the inner holding member 30 and the outer holding member 40 are assembled, the bases 23, 25 of the conductors 21, 22 can be pressed in the direction of the axis x and sandwiched between the holding portions 32, 42, allowing the conductors 21, 22 to be firmly sandwiched.

[0044] 2, 7, and 8, the side surface 42b of the holding portion 42 of the outer holding member 40 is provided with protruding portions 2a and 2b, which are portions protruding toward the front side, at circumferential positions corresponding to the gaps 11 and 12 of the conductive member 3, respectively. FIG. 7 is a cross-sectional view of a cross section taken along the line AA in FIG. 2, and FIG. 8 is a cross-sectional view of a cross section taken along the line BB in FIG. 2. In the conductive structure 1, the protruding portion 2a is accommodated in the gap 11, and the protruding portion 2b is accommodated in the gap 12. In the gap 11, the protruding portion 2a is adapted to contact the end 21a of the conductor 21 and the end 22a of the conductor 22, and in the gap 12, the protruding portion 2b is adapted to contact the end 21b of the conductor 21 and the end 22b of the conductor 22. In the gap 11, a gap may be formed between the protruding portion 2a and the end 21a of the conductor 21. In addition, in the gap 11, a gap may be formed between the protrusion 2a and the end 22a of the conductor 22. Similarly, in the gap 12, a gap may be formed between the protrusion 2b and the end 21b of the conductor 21. In addition, in the gap 12, a gap may be formed between the protrusion 2b and the end 22b of the conductor 22. The protrusions 2a and 2b may be provided on the side surface 32a of the holding portion 32 of the inner holding member 30, not on the side surface 42b of the holding portion 42 of the outer holding member 40, so as to be accommodated in the gaps 11 and 12, respectively. In addition to the side surface 42b of the holding portion 42 of the outer holding member 40, the protrusions 2a and 2b may also be provided on the side surface 32a of the holding portion 32 of the inner holding member 30. Furthermore, a plurality of protrusions 2a may be provided. Furthermore, a plurality of protrusions 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 each part of the integrally formed inner holding member 30 and are connected together. Similarly, the outer holding member 40 is integrally formed from the same material, and the fitting portion 41 and the holding portion 42 are each part of the integrally formed outer holding member 40 and are connected together. The inner holding member 30 and the outer holding member 40 are made from a conductive metal, but may be integrally formed from other conductive materials.

[0046] Each component of the conductive structure 1 has the configuration described above, and is assembled to form 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 toward the rear side, which is the opposite side to the front side, by the pressing portion 43 of the fitting portion 41 of the outer holding member 40. 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 periphery 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. The conductors 21, 22 are attached to the inner holding member 30 and the outer holding member 40 so that the respective contact portions 24, 26 protrude toward the front side. The conductors 21, 22 may also be attached to the inner holding member 30 and the outer holding member 40 so that the respective contact portions 24, 26 protrude toward the rear side.

[0047] Before the assembled state shown in Fig. 3 is reached, 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 in the fitting portion 41, and then the fitting portion 31 of the inner holding member 30 may be attached to the fitting portion 41 of the outer holding member 40, and then the pressing portion 43 may be formed in the fitting portion 41. In other words, by forming the pressing portion 43, the fitting portion 31 and the fitting portion 41 may be crimped together, and the end 31c of the fitting portion 31 may be pressed toward the back side in the direction of the axis 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 in the assembled state shown in Fig. 3.

[0048] In addition, in the assembled state shown in Figure 3, the convex portions 2a, 2b formed on the holding portion 42 of the outer holding member 40 are respectively accommodated 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.

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

[0050] As an example, the conductive structure 1 is provided between the housing 111 and the shaft 110 of the electric motor 101, and is in a state of use. 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, and the conductive structure 1 is in a state of use. In the state of use, the inner circumferential ends 24c, 26c of the conductors 21, 22 of the conductive member 3 are in contact with the outer circumferential surface 110a of the shaft 110. In addition, 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 metal having electrical conductivity, and is in contact with the inner circumferential surface 113a of the shaft hole 113 of the housing 111. In this way, the conductive member 3 and the holding member 2 form a conductive path that allows electricity to flow between the shaft 110 of the electric motor 101 and the housing 111 in the state of use.

[0051] The conductive structure 1 may also be provided between the housing 120 and the shaft 110 of the reducer 102. Specifically, as shown in Fig. 9, the conductive structure 1 may be provided outside the oil seal 125 in a gap between the shaft hole 124 of the housing 120 and the shaft 110. 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 a conductive path for passing electricity between the shaft 110 of the electric motor 101 and the housing 120 of the reducer 102. Similarly, the conductive structure 1 may also be provided outside the oil seal 127 in a gap between the shaft hole 126 of the housing 120 and the shaft 122.

[0052] The above-mentioned drive device 100 is an example of an 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 a drive device of an electric vehicle (EV) such as a hybrid vehicle (HV) or a fuel cell vehicle (FCV) other than a battery electric vehicle (BEV). In a vehicle equipped with an electric motor such as an electric vehicle (EV), electromagnetic noise may be generated due to an induced current generated from the motor. In addition, electromagnetic noise may be generated due to the on / off operation of an inverter for controlling a current supplied to an electric motor such as an electric motor, or due to an induced voltage of the electric motor itself. As described above, the conductive structure 1 forms a conductive path and causes the electromagnetic noise transmitted to the shaft 110 to flow to the housings 111 and 120. This makes it possible to prevent communication failure or malfunction in electronic devices and electrolytic corrosion in metal parts such as bearings.

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

[0054] Furthermore, in the conductive member 3, the conductors 21, 22 are arranged in an annular shape with gaps 11, 12 interposed therebetween. Therefore, even if an external force is applied to the conductors 21, 22 due to the rotation of the shaft 110 in a used state, the conductors 21, 22 can escape to the gaps 11, 12, and deformation that would cause stress concentration or contact with the shaft 110 can be suppressed in the conductors 21, 22. This makes it possible to suppress wear and settling of the conductors 21, 22. In this respect, the conductive structure 1 does not require the provision of a conductive lubricant between the conductors 21, 22 and the shaft 110.

[0055] Moreover, 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. In this way, only an annular space surrounding the outer peripheral surface 110a of the shaft 110 is required to attach the conductive structure 1. 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 and 124, so there is no need to provide additional space in the housing 111 for attaching the conductive structure 1. Even if 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, it is only necessary to provide a small annular space on the inner peripheral surface 113a of the shaft hole 113 for attaching the conductive structure 1. In this way, the conductive structure 1 can reduce the space in which the conductive structure 1 is attached, thereby enabling space saving.

[0056] Furthermore, in the conductive member 3, the conductors 21 and 22 are arranged in a ring shape with gaps 11 and 12 interposed therebetween. Therefore, when the conductive member 3 is fixed to the holding member 2, the conductors 21 and 22 can escape to the gaps 11 and 12. This makes it possible to prevent the conductors 21 and 22 from being deformed, such as wrinkled, when the conductive member 3 is fixed to the holding member 2.

[0057] Furthermore, intermediate products for the conductors 21 and 22 that are formed into the shapes of the conductors 21 and 22 can be produced by cutting out a plurality of pieces from a single sheet-like material. Therefore, the conductors 21 and 22 can be produced efficiently with a high yield.

[0058] 3, the protrusions 2a, 2b formed on the holding portion 42 of the outer holding member 40 are respectively housed 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, the conductors 21, 22 do not rotate relative to the holding member 2 when the shaft 110 rotates.

[0059] As described above, the conductive structure 1 according to the first embodiment of the present invention can reduce the space required and prevent the conductive performance from decreasing when in use.

[0060] Next, a modified example of the 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 does not have one of the gaps 11 or 12 of the conductive member 3, and the conductor 21 or 22 extends to one part of the gap 11 or 12, and the conductor 21 and the conductor 22 are connected to each other in one part of the gap 11 or 12 to form one conductor 20. As shown in FIG. 11, the conductor 20 of the conductive member 3A according to the modified example extends on a circle or an approximately circle centered or approximately centered on the axis x, for example, and the end 20a and the end 20b face each other in the circumferential direction, specifically, for example, face each other in a direction perpendicular to the axis x. The cross-sectional shape of the conductor 20 is the cross-sectional shape of the conductor 21. The conductive member 3 may have three or more gaps 10 and three or more conductors 20. In this case as well, the multiple gaps 10 and the multiple conductors 20 are connected in a ring shape.

[0061] Next, a conductive structure 4 according to a 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 perspective cross-sectional view in which a part of the conductive structure 4 shown in FIG. 12 is cut away. 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 of the cross section of the conductive structure 4 taken along a plane including the axis x. The conductive structure 4 according to this embodiment differs from the conductive structure 1 described above mainly in that it includes a spring member 50. Hereinafter, regarding the configuration of the conductive structure 4, the same reference numerals will be used to denote configurations that are the same as or have similar functions to those of the conductive structure 1 described above, and a description of these configurations will be omitted, and different configurations will be described.

[0062] As described above, the conductive structure 4 has the spring member 50. As shown in Figs. 11 to 15, the spring member 50 is an annular spring member around the axis x and generates an elastic force in a direction toward the axis x. The spring member 50 is arranged in line with the conductive member 3 in the direction of the axis x. The direction toward the axis x is not limited to a direction toward the inner periphery in the radial direction, but may be any direction having a component toward the inner periphery in the radial direction. Specifically, the spring member 50 is an annular leaf spring and can generate an elastic force to support the contact portions 24, 26 of the conductors 21, 22 of the conductive member 3 so that the contact portions 24, 26 contact the outer circumferential surface 110a of the shaft 110 (see Fig. 10). For example, as shown in Fig. 15, the spring member 50 is shaped to follow the side surfaces 23a, 24a and side surfaces 25a, 26a of the conductors 21, 22, respectively. 15, the spring member 50 is sandwiched between the holding portion 32 of the inner holding member 30 and the bases 23, 25 of the conductors 21, 22 and fixed in the conductive structure 4, and the conductive structure 4 is thus capable of holding the spring member 50. Specifically, in an 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 also so that the base 25 of the conductor 22 can be pressed and sandwiched in the direction of the axis x.

[0063] The spring member 50 has a base 51 and an elastic portion 52, as shown in Figs. 14 and 15, for example. The base 51 is a portion sandwiched between the holding portion 32 of the inner holding member 30 and the bases 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, for example, along a cylindrical surface whose diameter decreases toward the front side in the direction of the axis x. The thickness of the spring member 50 is set, for example, according to 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 a leaf spring having a plurality of spring pieces protruding toward the inner periphery and arranged around the axis x, as shown in Figs. 13 and 14. The specific form of the spring member 50 may be other forms. The spring member 50 may not extend continuously in an endless annular shape, but may extend in an annular shape with ends, or may be a plurality of spring members extending in an arc arranged discontinuously in an annular shape. For example, the spring member 50 may not be an endless annular shape as shown in the drawings, but may be two spring members extending on an arc corresponding to the conductors 21 and 22, respectively.

[0064] As described above, in the conductive structure 4, an elastic force toward the axis x is generated in the contact portions 24, 26 of the conductors 21, 22 of the conductive member 3. Therefore, the conductors 21, 22 are supported by the spring member 50 so as to contact the outer circumferential surface 110a of the shaft 110. This prevents the conductors 21, 22 from losing contact with the shaft 110 due to weakening or deformation of the conductors 21, 22 over time.

[0065] The conductive structure 4 is also used in the same manner as the conductive structure 1 described above to form a conductive path. Similarly to the conductive structure 1, the conductive structure 4 can also eliminate the need for a lubricant, and can suppress the conductive performance of the conductive structure 1 from deteriorating during use. The conductive structure 4 can also eliminate or reduce the space in which the conductive structure 4 is attached, making it possible to save space. The conductive structure 4 can also suppress the occurrence of deformation such as wrinkles in the conductors 21 and 22 when the conductive member 3 is fixed to the holding member 2. The conductors 21 and 22 of the conductive structure 4 can also be manufactured efficiently with a high yield. Also, in the conductive structure 4, the conductors 21 and 22 do not rotate relative to the holding member 2 due to the rotation of the shaft 110.

[0066] As described above, the conductive structure 4 according to the second embodiment of the present invention can reduce the space required and prevent the conductive performance from decreasing when in use.

[0067] Next, a conductive sealing device 5 according to a first embodiment of the present invention will be described. Fig. 16 is a cross-sectional view showing one side of a cross section along 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 a seal between a shaft of an application object and a hole through which the shaft passes, and is also a conductive structure that forms 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 part 70 formed of an elastic body which is annular around the axis x and which is attached to the reinforcing ring 60, and a conductive structure 6 which is annular around the axis x. The elastic body part 70 has a seal lip 71 which contacts the shaft. The conductive structure 6 includes 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 which is provided so as to extend in a radial direction, and at least one conductive conductor 20 which extends around the axis x. The holding member 45 is attached to the elastic body part 70 and holds the conductor 20 between the holding member 45 and the elastic body part 70. The conductor 20 has a pair of ends 20a in the direction around the axis x, and the gap 10 is connected to the ends 20a, 20b of the conductor 20. The configuration of the conductive sealing device 5 will be specifically described below.

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

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

[0071] The cover portion 74 also 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 perpendicular to the axis x. Specifically, the holding surface 77 is, for example, a surface extending on a plane parallel or approximately parallel to the plane perpendicular 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 conductive structure 1 described above, and the conductive member 3 of the conductive structure 1 described above (see FIG. 4). 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 from the end of the fitting portion 46 to the inner periphery side. 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 each other in the direction of the axis x, and has a substantially rectangular cross-sectional shape. 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 tubular surface extending along the axis x, for example, a cylindrical surface or an approximately cylindrical surface with the axis x as the central axis or approximately the central axis. As shown in Fig. 16, the holding portion 47 has side surfaces 47a, 47b which are surfaces facing each other in the direction of the axis x, and has a rectangular or approximately rectangular cross-sectional shape. The side surface 47b connected to the inner peripheral surface 46b of the fitting portion 46 extends along a plane perpendicular to the axis x, for example, on a plane parallel or approximately parallel to the plane perpendicular to the axis x.

[0073] The fitting portion 46 of the holding member 45 can be fitted 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. As a result, the cover portion 74 of the elastic body portion 70 is press-fitted into the fitting portion 46 of the holding member 45, and 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 surface 47b of the holding portion 47 contacts the respective side surfaces 23a, 25a of the bases 23, 25 of the conductors 21, 22 of the conductive member 3, and presses 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 into the outer peripheral end portion 74a of the cover portion 74 of the elastic body portion 70, and the holding portion 47 presses the bases 23, 25 against the holding surface 77 of the cover portion 74, and the holding member 45 is fixed to the elastic body portion 70. 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 retaining member 45 is fitted into the outer peripheral end portion 74a of the cover portion 74 of the elastic body portion 70, the convex portion 48 is accommodated in the concave portion 76, so that the retaining member 45 can be more firmly fixed to the elastic body portion 70 with the retaining portion 47 pressing the bases 23, 25 against the retaining 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 adapted to come into contact with the outer circumferential surface of the shaft to which the device is applied. Also, as shown in Fig. 16, the contact portions 24, 26 of the conductors 21, 22 protrude to the side opposite to the side to be sealed.

[0076] Moreover, the side surface 47b of the holding portion 47 of the holding member 45 is similarly provided with the convex portions 2a and 2b of the conductive structure 1 described above, and in the conductive sealing device 5, the convex portions 2a and 2b are accommodated in the gaps 11 and 12 of the conductive member 3, respectively. 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. In the gap 11, a gap may be formed between the convex portion 2a and the end 21a of the conductor 21. 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. In the gap 12, a gap may be formed between the convex portion 2b and the end 22b of the conductor 22. The protrusions 2a and 2b may be provided on the holding surface 77 of the cover portion 74 of the elastic body portion 70, instead of on the side surface 47b of the holding portion 47 of the holding member 45, so as to be similarly accommodated in the gaps 11 and 12, respectively. The protrusions 2a and 2b may be provided on the holding surface 77 of the cover portion 74 of the elastic body portion 70, in addition to the side surface 47b of the holding portion 47 of the holding member 45. A plurality of protrusions 2a may be provided. A plurality of protrusions 2b may be provided.

[0077] Each component of the conductive sealing device 5 has the above-mentioned configuration, and is assembled to obtain the conductive sealing device 5 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 manner, 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. The conductors 21 and 22 are attached between the holding member 45 and the elastic body portion 70 so that the contact portions 24 and 26 of the conductors 21 and 22 protrude to the side opposite to the seal lip 71 side. The conductors 21 and 22 may be attached so that the contact portions 24 and 26 of the conductors 21 and 22 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 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 use 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 a similar configuration to the above-mentioned 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. In addition, the conductive sealing device 5 is attached to the drive device 200 instead of the oil seals 125 and 127 of the drive device 100. As an example, the conductive sealing device 5 is provided between the housing 120 and the shafts 110 and 122 of the reducer 102 and is in a use state. Specifically, the gasket portion 73 of the elastic body portion 70 is fitted into the axial holes 124 and 126 of the housing 120, the conductive sealing device 5 is fixed to the axial holes 124 and 126, and the shafts 110 and 122 are inserted into the seal lip 71 and the conductive member 3, so that the conductive sealing device 5 is in a use state. In the use state, the seal lip 71 contacts the outer circumferential surfaces 110a and 122a of the shafts 110 and 122, and the sealed object side is sealed. In addition, in the use state, the inner circumferential ends 24c and 26c of the conductors 21 and 22 of the conductive member 3 contact the outer circumferential surfaces 110a and 122a of the shafts 110 and 122, respectively. In addition, the holding member 45 to which the conductive member 3 is attached is made of a metal having conductivity, and contacts the inner circumferential surfaces 124a and 126a of the axial holes 124 and 126 of the housing 120. In this manner, the conductive member 3 and the holding member 45 form a conductive path that allows electricity to flow between the shafts 110, 122 and the housing 120 in the used state.

[0079] The above-mentioned drive device 200 is an example of an 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 in drive devices of electric vehicles (EVs) such as hybrid vehicles (HVs) and fuel cell vehicles (FCVs) in addition to battery electric vehicles (BEVs). In vehicles equipped with electric motors such as electric vehicles (EVs), electromagnetic noise may be generated by induced currents generated from the motors. In addition, electromagnetic noise may be generated by the on / off operation of an inverter for controlling the current supplied to electric motors such as electric motors, or by induced voltages of the electric motors themselves. As described above, the conductive sealing device 5 forms a conductive path and causes electromagnetic noise transmitted to the shafts 110 and 122 to flow to the housing 120. This makes it possible to prevent communication failures and malfunctions in electronic devices and electrolytic corrosion in metal parts such as bearings.

[0080] The conductive structure 6 of the conductive sealing device 5 is used in the same manner as the conductive structure 1 described above to form a conductive path. Similarly to the conductive structure 1, the conductive structure 6 can also eliminate the need for a lubricant, and the conductive performance of the conductive structure 6 can be prevented from deteriorating in use. Even if an external force is applied to the conductors 21 and 22 due to the rotation of the shafts 110 and 122, the conductive member 3 of the conductive sealing device 5 can also prevent the conductors 21 and 22 from being deformed to cause stress concentration or from contacting the shafts 110 and 122. In this respect, the conductive sealing device 5 does not require a conductive lubricant between the conductors 21 and 22 and the shafts 110 and 122, similar to the conductive structure. Furthermore, since the conductive structure 6 is attached between the radial width of the sealing device, no space is required for attaching the conductive structure 6, and space saving is possible. Also, in the conductive sealing device 5, when the conductive member 3 is fixed between the holding member 45 and the elastic body portion 70, deformation such as wrinkles can be prevented from occurring in the conductors 21 and 22. The conductors 21, 22 of the conductive structure 6 are also manufactured efficiently with a high yield. Also, in the conductive sealing device 5, the conductors 21, 22 do not rotate relative to the holding member 45 and the elastic portion 70 when the shafts 110, 122 rotate.

[0081] Further, the conductive member 3 of the conductive structure 6 has gaps 11, 12 between the conductor 21 and the conductor 22. Since the gaps 11, 12 are through holes penetrating the conductive member 3 in the axial x direction, when the conductive sealing device 5 is in use, a through hole penetrating the conductive member 3 in the axial x direction is formed between the shafts 110, 122 and the axial holes 124, 126. As shown in FIG. 16, the seal lip 71 has a plurality of spirally extending convex portions 71a, and the convex portions 71a perform a pumping action. Therefore, when in use, the seal lip 71 draws air into the sealed object side. As described above, the conductive member 3 forms a through hole penetrating the conductive member 3 in the axial x direction between the shafts 110, 122 and the axial holes 124, 126, so even if air is drawn into the sealed object side by the pumping action of the seal lip 71, the space between the conductors 21, 22 of the conductive member 3 and the seal lip 71 does not become a negative pressure state. This makes it possible to prevent wear of the seal lip 71 and an increase in sliding resistance, and also makes it possible to prevent wear of the conductors 21 and 22 of the conductive member 3 and an increase in sliding resistance.

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

[0083] Similarly to the conductive structure 1, the conductive structure 6 of the conductive sealing device 5 can also be modified in various ways.

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

[0085] The above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. Moreover, the above-described embodiments do not limit the use of the present invention, and the present invention may include anything as its use. The components of the above-described embodiments, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those exemplified, and can be changed as appropriate. For example, the present invention includes differences that occur in the implementation of manufacturing tolerances, etc. Furthermore, the components shown in different embodiments can be partially replaced or combined with each other within a range that is not technically contradictory. Furthermore, each configuration can be appropriately and selectively combined so as to achieve at least a part of the above-described problems and effects.

[0086] For example, the shape of the outer peripheral end (ends 23c, 25c) of the conductive member 3 may be a shape having straight line portions along a straight line, instead of a shape along a circle. For example, as shown in FIG. 19, two pairs of straight line portions, a pair of straight line portions 3a and a pair of straight line portions 3b, may be provided at the outer peripheral end (ends 23c, 25c) of the conductive member 3. In this case, the rotation of the conductors 21, 22 can be prevented by providing a step portion or a protrusion corresponding to the straight line portions on the holding members 2, 7 and the cover portion 74 of the elastic body portion 70. For example, as shown in FIG. 20, a recess 77a having a contour corresponding to the contour of the outer peripheral end of the conductive member 3 as shown in FIG. 19 may be formed on the holding surface 77 of the cover portion 74 of the elastic body portion 70 of the conductive sealing device 5, and the conductive member 3 may be accommodated in the recess 77a. In this case, the protrusions 2a, 2b do not need to be provided, and even if the protrusions 2a, 2b are not provided, the conductors 21, 22 can be prevented from rotating relative to the holding member 45 and the elastic body portion 70 due to rotation of the shaft 110. Also, the conductor 20 (conductors 21, 22) and the holding members 2, 7 or the elastic body portion 70 may be bonded together using an adhesive. In this case, the adhesive is applied so as not to cause resistance in the conductive path. Also, in this case, an adhesive having electrical conductivity is used. [Explanation of symbols]

[0087] 1,4,6 Conductive structure, 2,7 Holding member, 2a,2b Convex part, 3,3A Conductive member, 3a,3b Straight part, 5 Conductive sealing device, 10,11,12 Gap, 20,21, 22 Conductor, 20a,20b,21a,21b,22a,22b Edge, 23,25 Base, 23a, 23b, 25a, 25b side surface, 23c, 25c end, 24, 26 contact part, 24a, 24b, 26a, 26b side surface, 24c, 26c inner peripheral end, 30 inner holding member, 31 fitting part, 31a outer peripheral surface, 31b inner peripheral surface, 31c end, 32 Holding part, 32a, 32b side, 32c end, 40 Outer holding member, 45 Holding member, 41, 46 fitting portion, 41a, 46a outer peripheral surface, 41b, 46b inner peripheral surface, 42, 47 holding portion, 42a, 42b, 47a, 47b side surface, 42c end, 43 pressing portion, 46c end, 48 convex portion, 50 spring member, 51 base portion, 52 elastic portion, 60 reinforcing ring, 61 cylindrical portion, 62 annular portion, 70 elastic portion, 71 seal lip, 71a convex portion, 72 base portion, 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 device, 101 electric motor, 102 reducer, 103 inverter, 104 battery, 105 Wheel, 110, 122 shaft, 110a, 122a outer peripheral surface, 111, 120 housing, 121 reduction gear stage, 112, 123 bearing, 113, 124, 126 shaft hole, 113a, 124a, 126a inner peripheral surface, 125, 127 oil seal, x-axis

Claims

1. A conductive structure forming a conductive path between a shaft and a hole through which the shaft is inserted, A holding member which is an annular conductive member around an axis line; a conductive member that is an annular member around the axis, the conductive member has at least one gap extending in a radial direction and at least one conductive body extending in a part of an annular shape around the axis line, the conductive member is held by the holding member, The conductor is adapted to contact the shaft and has a pair of ends in a direction around the axis, The gap is continuous with the end of the conductor. Conductive structure.

2. the conductive member has one of the conductors and one of the gaps, the pair of ends of the conductor are opposed to each other in a direction around the axis, the gap being the gap between the opposing ends of the conductor; The conductive structure of claim 1 .

3. the conductive member has two of the conductors and 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 of the conductors in a direction around the axis, the other of the pair of ends of one of the conductors faces the other of the pair of ends of the other of the conductors in a direction around the axis, one of the gaps is formed between the one end of the one conductor and the 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. The conductive structure of claim 1 .

4. The conductor is held by the holding member at an outer circumferential side. The conductive structure of claim 1 .

5. A ring-shaped spring member is provided around the axis, The spring member generates an elastic force in a direction toward the axis, The spring member is arranged next to the conductive member in the axial direction. The conductive structure of claim 1 .

6. The holding member has at least one protrusion that is received in the gap, The protruding portion protrudes in the axial direction. The conductive structure of claim 1 .

7. the conductor is formed from a resin that has become conductive, The resin is PTFE. The conductive structure of claim 1 .

8. 1. A conductive sealing device for providing a seal between a shaft and a bore through which the shaft passes, comprising: A reinforcing ring that is an annular member around an axis line; an elastic body portion formed of an annular elastic body around the axis and attached to the reinforcing ring; a conductive structure having an annular shape around the axis, The elastic body portion has a seal lip that contacts the shaft, the conductive structure includes a holding member that is an annular member around the axis line, and a conductive member that is an annular member around the axis line, the conductive member has at least one gap extending in a radial direction and at least one conductive body extending in a part of an annular shape around the axis line, the holding member is attached to the elastic body portion and holds the conductor between the holding member and the elastic body portion, The conductor is adapted to contact the shaft and has a pair of ends in a direction around the axis, The gap is continuous with the end of the conductor. Conductive sealing device.

9. the conductive member has one of the conductors and one of the gaps, the pair of ends of the conductor are opposed to each other in a direction around the axis, the gap being the gap between the opposing ends of the conductor; 9. The conductive sealing device of claim 8.

10. the conductive member has two of the conductors and 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 of the conductors in a direction around the axis, the other of the pair of ends of one of the conductors faces the other of the pair of ends of the other of the conductors in a direction around the axis, one of the gaps is formed between the one end of the one conductor and the 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.

9. The conductive sealing device of claim 8.

11. The holding member has at least one protrusion that is received in the gap, The protruding portion protrudes in the axial direction.

9. The conductive sealing device of claim 8.

12. the conductor is formed from a resin that has become conductive, The resin is PTFE.

9. The conductive sealing device of claim 8.

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