Conductive resin composition, conductive sliding body, and conductive structure

Abstract

A conductive structure (1) includes: a conductive member (10) formed of a ring-shaped conductive resin composition; and a holding member (20) that is a member having ring-shaped conductivity. The conductive member (10) is held by the holding member (20). The conductive resin member contains a fluororesin, a conductive material, and a wear-resistant material having conductivity. The fluororesin is polytetrafluoroethylene.

Description

Technical Field

[0001] The present invention relates to conductive resin compositions, conductive sliders, and conductive structures, and more particularly to conductive resin compositions, conductive sliders, and conductive structures for forming conductive pathways on a rotating shaft. Background Technology

[0002] For example, in vehicles equipped with electric motors, such as electric vehicles (EVs), the induced current generated by the motor sometimes causes electromagnetic noise. This type of electromagnetic noise can cause communication failures in AM radios and other wireless communication devices. Furthermore, this electromagnetic noise can also cause electrolytic corrosion of metal components such as bearings. Therefore, corresponding improvement measures have been implemented to eliminate this type of electromagnetic noise, and conductive structures and conductive devices that form conductive paths on rotating shafts have been proposed. For example, some technologies disclose mounting a conductive structure on a motor housing, where a disc-shaped conductive component made of conductive material contacts the motor's rotating shaft, forming a conductive path between the rotating shaft and the housing, thereby dissipating electromagnetic noise from the rotating shaft to the housing (see, for example, cited reference 1).

[0003] Prior art literature Patent documents Patent Document 1: Japanese Patent Publication No. 2019-509007. Summary of the Invention

[0004] The problem that the invention aims to solve The conductive components of a conductive structure slide relative to the axis of rotation; therefore, it has always been required that these components possess both conductivity and durability. For example, Patent Document 1 proposes using conductive PTFE, a conductive resin, to make the conductive components. However, for existing conductive structures, there is still a need to further improve both conductivity and durability.

[0005] The present invention was made in view of the above-mentioned problems, and its object is to provide a conductive resin composition, a conductive slider, and a conductive structure that can improve both conductivity and durability.

[0006] means for solving problems To achieve the above objectives, the conductive resin composition of the present invention contains a fluororesin, a conductive material, and a wear-resistant material with conductivity, wherein the fluororesin is polytetrafluoroethylene.

[0007] In a conductive resin composition according to one embodiment of the present invention, the wear-resistant material is coke.

[0008] In a conductive resin composition according to one embodiment of the present invention, the conductive material is carbon particles.

[0009] In a conductive resin composition according to one embodiment of the present invention, the conductive material is carbon black.

[0010] To achieve the above objectives, the conductive sliding body of the present invention is annular around axis x and is formed of a conductive resin composition, wherein the conductive resin composition contains a fluororesin, a conductive material, and a wear-resistant material with conductivity, and the fluororesin is polytetrafluoroethylene.

[0011] In a conductive structure according to one embodiment of the present invention, the wear-resistant material is coke.

[0012] In a conductive structure according to one embodiment of the present invention, the conductive material is carbon particles.

[0013] In a conductive structure according to one embodiment of the present invention, the conductive material is carbon black.

[0014] In a conductive structure according to one embodiment of the present invention, a shaft for rotating about the axis is inserted.

[0015] To achieve the above objectives, the conductive structure of the present invention is a conductive structure installed between a shaft and a hole through which the shaft passes, comprising: a conductive slider, which is a component that is annular about an axis x; and a support component, which is annular about the axis and supports the conductive slider, wherein the conductive slider is formed of a conductive resin composition, the conductive resin composition containing a fluororesin, a conductive material, and a wear-resistant material having conductivity, wherein the fluororesin is polytetrafluoroethylene.

[0016] In a conductive structure according to one embodiment of the present invention, the wear-resistant material is coke.

[0017] In a conductive structure according to one embodiment of the present invention, the conductive material is carbon particles.

[0018] In a conductive structure according to one embodiment of the present invention, the conductive material is carbon black.

[0019] Invention Effects The conductive resin composition, conductive slider, and conductive structure according to the present invention can improve both conductivity and durability. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view showing the schematic configuration of the conductive structure according to the first embodiment of the present invention, cut through a plane including the axis.

[0021] Figure 2 It means Figure 1 The conductive structure shown is a cross-sectional view relative to one side of the axis.

[0022] Figure 3 This is a conceptual diagram used to represent an application object of a conductive structure.

[0023] Figure 4 It means Figure 4 A cross-sectional view of an example of the usage state of a conductive structure in the application object shown.

[0024] Figure 5 This is a cross-sectional view showing the schematic configuration of the conductive sealing device according to an embodiment of the present invention, cut through a plane including the axis of the conductive sealing device and relative to one side of the axis.

[0025] Figure 6 This is a conceptual diagram used to represent an example of an application of a conductive sealing device.

[0026] Figure 7 It means Figure 6 A cross-sectional view of an example of the use of a conductive sealing device in the application shown.

[0027] Figure 8 This is a diagram schematically illustrating the method of measuring surface resistivity using the four-probe method. Detailed Implementation

[0028] Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that not all constituent elements are labeled with reference numerals in the drawings; some reference numerals for multiple constituent elements may be omitted.

[0029] Through dedicated research, the inventors have discovered that by adding conductive materials and conductive, wear-resistant materials to fluoropolymers, it is possible to improve both the conductivity and durability of the fluoropolymers. This invention was completed based on this insight and further, repeated research.

[0030] The conductive resin composition of the present invention is used, for example, to form a conductive slide body for inserting and sliding a shaft thereon. The conductive slide body is used, for example, to form a conductive path on a rotating shaft, specifically, for example, to form a conductive path between the shaft and a hole through which the shaft passes. The conductive resin composition of the present invention will be described below using a conductive slide body formed from the conductive resin composition of the present invention as an example. However, the applications of the conductive resin composition of the present invention are not limited to this.

[0031] Figure 1 This is a cross-sectional view showing the general configuration of the conductive structure 1 according to the first embodiment of the present invention, which includes the conductive component 10 as a conductive slider according to the embodiment of the present invention, and is cut through a plane including the axis x. Figure 2 It means Figure 1 The conductive structure 1 shown is a cross-sectional view relative to the x-axis.

[0032] like Figure 1 , Figure 2 As shown, the conductive structure 1 includes: a conductive member 10, which is a member formed of a conductive resin composition arranged in a ring around an axis x; and a retaining member 20, which is a conductive member arranged in a ring around an axis x. The conductive member 10 is held by the retaining member 20. The conductive resin composition contains a fluoropolymer, a conductive material, and a wear-resistant material that is conductive. The fluoropolymer is polytetrafluoroethylene (PTFE). The conductive resin composition will be described in detail later. The structure of the conductive structure 1 will be specifically described below. In addition, the inner circumferential side is the side close to the axis x in a direction orthogonal to the axis x (hereinafter also referred to as radial) (see Figure 1 Arrow c), the outer periphery is the side that is radially away from the axis x (see arrow c). Figure 1 Arrow d).

[0033] For example, such as Figure 1 , Figure 2 As shown, the conductive component 10 is a plate-shaped component that is annular about the axis x, having a contact side 11 and a back surface 12, which are a pair of annular surfaces facing away from each other in the direction of the axis x. Figure 1 , Figure 2 As shown, the contact side 11 faces one side of the axis x direction ( Figure 1 The side facing the direction of arrow a (hereinafter also referred to as the front side), the other side of the back 12 facing the x-axis ( Figure 1 The conductive member 10 has an annular inner peripheral end 10a at its inner peripheral end and an annular outer peripheral end 10b at its outer peripheral end. The inner peripheral end 10a defines a space (through hole) extending through the conductive member 10 along the x-axis on the inner peripheral side. For example, the inner peripheral end 10a extends along a circle centered on the x-axis. The outer peripheral end 10b also extends, for example, along a circle centered on the x-axis.

[0034] The conductive component 10 has an inner peripheral end 13 that is annular around the axis x, such as Figure 1 , Figure 2 As shown, the inner peripheral end 13 of the conductive member 10 extends along a plane orthogonal to the axis x. Alternatively, the inner peripheral end 13 of the conductive member 10 may not extend along a plane. The inner peripheral end 13 of the conductive member 10 may also have other shapes, for example, it may be bent or extended towards the back side.

[0035] like Figure 1 , Figure 2 As shown, the retaining member 20 specifically includes an inner retaining member 21 located on the inside and an outer retaining member 25 located on the outside. Both the inner retaining member 21 and the outer retaining member 25 are ring-shaped members about the axis x, configured to retain the conductive member 10 between each other.

[0036] like Figure 2 As shown, the inner retaining member 21 has, for example, a fitting portion 22 that is annular about the axis x, and a retaining portion 23 that is also annular about the axis x. The fitting portion 22 is a cylindrical portion extending along the axis x, and the retaining portion 23 is an annular portion extending from the front end of the fitting portion 22 toward the inner circumference. The fitting portion 22 is, for example, cylindrical or approximately cylindrical with the axis x as its central axis or approximately its central axis.

[0037] like Figure 2 As shown, the outer retaining member 25 has, for example, a fitting portion 26 that is annular about the axis x, and a retaining portion 27 that is also annular about the axis x. The fitting portion 26 is a cylindrical portion extending along the axis x, and the retaining portion 27 is an annular portion extending from the front end of the fitting portion 26 toward the inner circumference. The fitting portion 26 is, for example, cylindrical or approximately cylindrical with the axis x as its central axis or approximately its central axis.

[0038] like Figure 1 , Figure 2 As shown, the inner retaining member 21 and the outer retaining member 25 are configured to fit together. Specifically, for example, the diameter of the outer peripheral surface 22a of the fitting portion 22 of the inner retaining member 21 is larger than the diameter of the inner peripheral surface 26a of the fitting portion 26 of the outer retaining member 25. The fitting portion 22 of the inner retaining member 21 is pressed into the inner peripheral side of the fitting portion 26 of the outer retaining member 25, thereby fitting the fitting portion 22 of the inner retaining member 21 and the fitting portion 26 of the outer retaining member 25 together. Furthermore, the outer peripheral surface 22a of the fitting portion 22 is an annular surface facing the outer peripheral side of the fitting portion 22, and the inner peripheral surface 26a of the fitting portion 26 is an annular surface facing the inner peripheral side of the fitting portion 26. Additionally, as... Figure 1 , Figure 2 As shown, when the fitting portion 22 of the inner retaining member 21 and the fitting portion 26 of the outer retaining member 25 are fitted together, the retaining portion 23 of the inner retaining member 21 and the retaining portion 27 of the outer retaining member 25 have portions that are opposite to each other in the x-axis direction.

[0039] In addition, such as Figure 1 , Figure 2 As shown, with the inner retaining member 21 and the outer retaining member 25 engaged, the retaining portion 23 of the inner retaining member 21 and the retaining portion 27 of the outer retaining member 25 are opposite to the conductive member 10 in the x-axis direction. Specifically, the back surface 12 at the outer peripheral end 14 of the conductive member 10 is opposite to the retaining portion 23 of the inner retaining member 21, and the contact side surface 11 at the outer peripheral end 14 of the conductive member 10 is opposite to the retaining portion 27 of the outer retaining member 25. Furthermore, the outer peripheral end 14 is the outer peripheral end of the conductive member 10. Figure 1 , Figure 2As shown, the inner peripheral end 13 of the conductive member 10 is located further to the inner peripheral side than the holding portion 23 of the inner holding member 21, and is located further to the inner peripheral side than the holding portion 27 of the outer holding member 25.

[0040] like Figure 2 As shown, with the inner retaining member 21 and the outer retaining member 25 engaged, and the conductive member 10 clamped at its outer peripheral end 14 between the retaining portion 23 of the inner retaining member 21 and the retaining portion 27 of the outer retaining member 25 and pressed along the x-axis, the engaging portion 26 of the outer retaining member 25 forms a pressing portion 28, and the inner retaining member 21 is fixed to the outer retaining member 25. Furthermore, the pressing portion 28 of the outer retaining member 25 contacts the engaging portion 22 of the inner retaining member 21 and fixes the engaging portion 22 along the x-axis. Thus, the conductive member 10 is fixed between the inner retaining member 21 and the outer retaining member 25 (hereinafter also referred to as the "assembled state").

[0041] The inner retaining member 21 and the outer retaining member 25 are made of a conductive metal. Alternatively, the inner retaining member 21 and the outer retaining member 25 may also be formed of other conductive materials.

[0042] Each component of the conductive structure 1 has the above-described configuration, and they are assembled into an assembled state, forming as shown. Figure 1 , Figure 2 The conductive structure 1 is shown. In the conductive structure 1, the fitting portion 22 of the inner retaining member 21 fits into the fitting portion 26 of the outer retaining member 25, and the fitting portion 22 of the inner retaining member 21 is pressed towards the front side by the pressing portion 28 of the fitting portion 26 of the outer retaining member 25. Furthermore, the conductive member 10 is held between the holding portion 23 of the inner retaining member 21 and the holding portion 27 of the outer retaining member 25. The conductive member 10 is held at its outer peripheral end 14 by the inner retaining member 21 and the outer retaining member 25. Thus, the inner retaining member 21 is fixed to the outer retaining member 25, and the conductive member 10 is fixed between the inner retaining member 21 and the outer retaining member 25. Furthermore, the conductive member 10 is mounted on the inner retaining member 21 and the outer retaining member 25 such that, in the usage state described below, the contact side 11 of the conductive member 10 contacts the shaft. Additionally, as... Figure 1 , Figure 2 As shown, the conductive component 10 is mounted on the inner retaining component 21 and the outer retaining component 25 with the contact side 11 of the conductive component 10 facing the front side. However, the conductive component 10 can also be mounted on the inner retaining component 21 and the outer retaining component 25 with the contact side 11 of the conductive component 10 facing the back side.

[0043] In becoming like Figure 1 , Figure 2Before the assembly state shown, the fitting portion 26 of the outer retaining member 25 may not have the pressing portion 28. For example, the conductive member 10 can be installed on the outer retaining member 25 without the pressing portion 28 formed on the fitting portion 26, and then the fitting portion 22 of the inner retaining member 21 can be installed on the fitting portion 26 of the outer retaining member 25, and then the pressing portion 28 can be formed on the fitting portion 26. That is, by forming the pressing portion 28, the fitting portion 22 is riveted to the fitting portion 26, and the end of the fitting portion 22 is pressed towards the front side by the pressing portion 28, thereby the conductive member 10, the inner retaining member 21 and the outer retaining member 25 can be configured as shown. Figure 1 , Figure 2 The assembly state is shown.

[0044] The function of conductive structure 1 will be explained next. Figure 3 This is a conceptual diagram used to represent an example of an application of conductive structure 1. Figure 4 It means Figure 3 A cross-sectional view of an example of the usage state of conductive structure 1 in the application shown. As an example, conductive structure 1 is as follows... Figure 3 The drive unit 100 shown is applied to a battery electric vehicle (BEV). For example, as... Figure 3 As shown, the drive unit 100 includes an electric motor 101, a reducer 102, an inverter 103 for controlling the electric motor 101, and a battery 104 as a power source. In the electric motor 101, a shaft 110 is rotatably supported by a bearing 112 within a housing 111 and extends out of the housing 111 through a shaft hole 113. The shaft 110 of the electric motor 101 passes through a shaft hole 124 into the housing 120 of the reducer 102 and is rotatably supported by a bearing 123 within the housing 120. Furthermore, the shaft 110 is connected to a reduction gear section 121 within the housing 120. The reducer 102 is provided with a shaft 122 that outputs the rotational driving force reduced by the reduction gear section 121. The shaft 122 is rotatably supported by a bearing 123 within the housing 120 and is connected to a wheel 105, enabling the transmission of rotational driving force to the wheel 105. An oil seal 125 is installed in the shaft hole 124 of the housing 120 of the reducer 102 to seal the gap between the shaft hole 124 and the shaft 110 of the electric motor 101. An oil seal 127 is installed in the shaft hole 126 of the housing 120 through which the shaft 122 of the reducer 102 passes to seal the gap between the shaft hole 126 and the shaft 122. In addition, the shaft 110 and housing 111 of the electric motor 101 are made of metal, and the housing 120 and shaft 122 of the reducer 102 are also made of metal.

[0045] As an example, the conductive structure 1 is disposed between the housing 111 and the shaft 110 of the electric motor 101, and is put into use. Specifically, as... Figure 4As shown, the fitting portion 26 of the outer retaining member 25 of the retaining member 20 is fitted into the shaft hole 113 of the housing 111, thereby fixing the conductive structure 1 to the shaft hole 113, and inserting the shaft 110 into the conductive member 10, thus putting the conductive structure 1 into use. In use, the contact side 11 at the inner peripheral end 13 of the conductive member 10 contacts the outer peripheral surface 110a of the shaft 110, and the inner peripheral end 13 of the conductive member 10 is deformed by being pressed outward by the shaft 110. Figure 4 As shown, the inner peripheral end 13 of the conductive member 10 has a width in the x-axis direction and contacts the outer peripheral surface 110a of the shaft 110. Furthermore, the retaining member 20 (inner retaining member 21 and outer retaining member 25) on which the conductive member 10 is mounted is made of a conductive metal and contacts the inner peripheral surface 113a of the shaft hole 113 of the housing 111. Thus, in use, the conductive member 10 and the retaining member 20 form a conductive path for current flow between the shaft 110 of the electric motor 101 and the housing 111.

[0046] Alternatively, the conductive structure 1 can also be disposed between the housing 120 and the shaft 122 of the reducer 102. Specifically, as follows: Figure 3 As shown, a conductive structure 1 can be provided on the outside of the oil seal 127, in the gap between the shaft hole 126 of the housing 120 and the shaft 122. In this case, similar to the conductive structure 1 installed on the electric motor 101, the conductive component 10 and the retaining component 20 of the conductive structure 1 form a conductive path for current flow between the shaft 122 of the reducer 102 and the housing 120.

[0047] Furthermore, the aforementioned drive unit 100 is one example of the application of the conductive structure 1, but its application is not limited to this. For example, in addition to battery electric vehicles (BEVs), the conductive structure 1 can also be used in drive units for electric vehicles (EVs) such as hybrid electric vehicles (HVs) and fuel cell vehicles (FCVs). In electric vehicles (EVs) and other vehicles equipped with electric motors, the induced current generated by the motor can sometimes generate electromagnetic noise. In addition, the switching operation of the inverter that controls the current supplied to the electric motor or other motor, or the induced voltage of the motor itself, can also sometimes generate electromagnetic noise. As described above, the conductive structure 1 forms a conductive path, allowing the electromagnetic noise transmitted to the shafts 110 and 122 to flow to the housings 111 and 120. This prevents communication failures or malfunctions in electronic equipment and prevents electrolytic corrosion of metal parts such as bearings.

[0048] Additionally, the conductive structure 1 may also include a support member, which is an annular member made of elastic material stacked from the back side 12 of the conductive member 10. In the conductive structure 1 in use, the support member presses the inner peripheral end 13 of the conductive member 10 against the outer peripheral surface 110a of the shaft 110. This improves the stability of the contact between the conductive member 10 and the shaft 110. Furthermore, the shape of the conductive member 10 is not limited to the shape described above. For example, the conductive member 10 may be divided into multiple parts. Also, the conductive member 10 may have a radially extending slit, and its shape when viewed along the x-axis is arc-shaped or circular.

[0049] The conductive sealing device 2, which is a conductive structure, according to the second embodiment of the present invention will now be described. Figure 5 This is a cross-sectional view showing the schematic configuration of the conductive sealing device 2, cut through a plane containing the axis x of the conductive sealing device 2 and relative to one side of the axis x. The conductive sealing device 2 is a sealing device used to seal between the shaft of the application object and the hole through which the shaft passes, and also a conductive structure that forms a conductive path between the shaft and the hole through which the shaft passes.

[0050] like Figure 5 As shown, the conductive sealing device 2 includes: a reinforcing ring 30, which is a ring-shaped component about an axis x; an elastic body portion 40, which is mounted on the reinforcing ring 30 and is formed of an elastic body about an axis x; and a conductive structure portion 3, which is ring-shaped about an axis x. The elastic body portion 40 has a sealing lip 41 that contacts the shaft. The conductive structure portion 3 includes: a retaining member 50, which is a ring-shaped component about an axis x; and the aforementioned conductive component 10. The conductive component 10 is held by the retaining member 50. The configuration of the conductive sealing device 2 will be described in detail below.

[0051] like Figure 5 As shown, the conductive sealing device 2 includes, for example, a reinforcing ring 30 and an elastomer portion 40 similar to those of a known oil seal. The reinforcing ring 30 has a cylindrical portion 31 and an annular portion 32. Furthermore, the elastomer portion 40, in addition to the sealing lip 41, also has a base 42, a gasket portion 43, and a cover portion 44. The sealing lip 41 extends from the base 42 toward the object to be sealed. The gasket portion 43 is the portion that covers the cylindrical portion 31 of the reinforcing ring 30 from its outer peripheral side and is pressed into the hole of the object to be sealed. The outer peripheral surface 43a of the gasket portion 43 is formed to a diameter that allows it to be pressed into the hole of the object to be sealed. The cover portion 44 is the portion that covers the annular portion 32 of the reinforcing ring 30 from the opposite side of the object to be sealed.

[0052] like Figure 5As shown, the outer peripheral end (outer peripheral end 44a) of the cover portion 44 has a fitting surface 45 forming an annular surface facing the outer peripheral side. The fitting surface 45 is, for example, a cylindrical surface extending along a cylindrical surface with the axis x as its central axis. Specifically, the fitting surface 45 is, for example, a cylindrical surface or an approximately cylindrical surface with the axis x as its central axis or approximately its central axis. For example, as... Figure 5 As shown, the mating surface 45 is located further outward than other parts of the outer peripheral end 44a, and an annular recess 46 is formed between it and the gasket portion 43, recessed inward. The mating surface 45 of the cover portion 44 is located radially further inward than the outer peripheral surface 43a of the gasket portion 43.

[0053] Furthermore, the cover portion 44 has a retaining surface 47 that is an annular surface facing the opposite side to the object to be sealed. The retaining surface 47 is, for example, a surface extending along a plane orthogonal to the axis x. Specifically, the retaining surface 47 is, for example, a surface extending parallel or approximately parallel to a plane orthogonal to the axis x.

[0054] like Figure 5 As shown, the retaining member 50 of the conductive structure 3 has the same shape as the outer retaining member 25 of the retaining member 20 of the conductive structure 1 described above. The retaining member 50 is made of the same conductive material as the outer retaining member 25. Figure 5 As shown, the retaining member 50 includes, for example, a fitting portion 51 that is annular about the axis x; and a retaining portion 52 that is also annular about the axis x. The fitting portion 51 is a cylindrical portion extending along the axis x, and the retaining portion 52 is an annular portion extending from the front end of the fitting portion 51 toward the inner circumference. Figure 5 As shown, the fitting portion 51 has, for example, an outer peripheral surface 51a and an inner peripheral surface 51b that are radially opposite to each other. The outer peripheral surface 51a is an annular surface facing the outer peripheral side, and the inner peripheral surface 51b is an annular surface facing the inner peripheral side. The inner peripheral surface 51b is a cylindrical surface extending along the axis x, for example, a cylindrical surface or an approximately cylindrical surface with the axis x as its central axis or approximately its central axis. Furthermore, as... Figure 5 As shown, the retaining part 52 has, for example, side surfaces 52a and 52b that are opposite to each other in the x-axis direction. The side surface 52b connected to the inner peripheral surface 51b of the fitting part 51 extends along a plane orthogonal to the x-axis, for example, extending on a plane parallel or approximately parallel to the plane orthogonal to the x-axis.

[0055] The fitting portion 51 of the retaining member 50 can fit into the outer peripheral end 44a of the cover portion 44 of the elastomer portion 40. Specifically, for example, the diameter of the inner peripheral surface 51b of the fitting portion 51 is smaller than the diameter of the fitting surface 45 of the outer peripheral end 44a of the cover portion 44. As a result, the cover portion 44 of the elastomer portion 40 is pressed into the fitting portion 51 of the retaining member 50, thereby fixing the retaining member 50 to the elastomer portion 40.

[0056] like Figure 5 As shown, the conductive member 10 is held between the holding portion 52 of the holding member 50 and the holding surface 47 of the cover portion 44 of the elastomer portion 40. Specifically, the side surface 52b of the holding member 50 contacts the back surface 12 at the outer peripheral end 14 of the conductive member 10, pressing the outer peripheral end 14 of the conductive member 10 against the holding surface 47 of the cover portion 44. As described above, the fitting portion 51 of the holding member 50 fits into the outer peripheral end 44a of the cover portion 44 of the elastomer portion 40, and the holding portion 52 presses the conductive member 10 against the holding surface 47 of the cover portion 44, thus fixing the holding member 50 to the elastomer portion 40. Alternatively, a protrusion 53 that is housed within the recess 46 of the cover portion 44 may be provided at the end 51c of the fitting portion 51 of the holding member 50 (see [link to relevant documentation]). Figure 5 As described above, by fitting the fitting portion 51 of the retaining member 50 into the outer peripheral end 44a of the cover portion 44 of the elastomer portion 40 and then housing the protrusion 53 in the recess 46, the retaining member 50 can be more securely fixed to the elastomer portion 40 while the retaining portion 52 presses the conductive member 10 against the retaining surface 47 of the cover portion 44.

[0057] In the conductive sealing device 2, similar to the conductive component 10 in the conductive structure 1 described above, the contact side 11 at the inner peripheral end 13 of the conductive component 10 contacts the outer peripheral surface of the shaft of the object being applied.

[0058] The components of the conductive sealing device 2 have the above-described configuration, and are assembled into an assembled state, forming as shown. Figure 5 The conductive sealing device 2 is shown. In the conductive sealing device 2, the fitting portion 51 of the retaining member 50 fits into the outer peripheral end 44a of the cover portion 44 of the elastic body portion 40, and the conductive member 10 is clamped between the retaining portion 52 of the retaining member 50 and the cover portion 44 of the elastic body portion 40. Thus, the retaining member 50 is fixed to the elastic body portion 40, and the conductive member 10 is fixed between the retaining member 50 and the elastic body portion 40.

[0059] Figure 6 This is a conceptual diagram illustrating an example of the application of the conductive sealing device 2. Figure 7 It means Figure 6 The diagram shows a cross-sectional view of an example of the conductive sealing device 2 in use within an application object. As an example, the conductive sealing device 2 is as follows... Figure 6 The drive unit 200 shown is applied to a battery electric vehicle (BEV). The drive unit 200 has features similar to the drive unit 100 described above (see [link]). Figure 3 , Figure 4The gearbox 102 has the same configuration, but differs from the drive unit 100 in that it does not have a conductive structure 1. Furthermore, in the drive unit 200, a conductive sealing device 2 is installed instead of the oil seal 127 of the drive unit 100. As an example, the conductive sealing device 2 is positioned between the housing 120 and the shaft 122 of the gearbox 102, and is in use. Specifically, the gasket portion 43 of the elastomer portion 40 fits into the shaft hole 126 of the housing 120, thereby fixing the conductive sealing device 2 to the shaft hole 126, and the shaft 122 is inserted into the sealing lip 41 and the conductive component 10, thus the conductive sealing device 2 is in use. In use, the sealing lip 41 contacts the outer peripheral surface 122a of the shaft 122, sealing the object being sealed. Furthermore, in use, the contact side 11 at the inner peripheral end 13 of the conductive component 10 contacts the outer peripheral surface 122a of the shaft 122. Furthermore, the retaining member 50 of the conductive member 10 is made of a conductive metal and contacts the inner circumferential surface 126a of the shaft hole 126 of the housing 120. Thus, in use, the conductive member 10 and the retaining member 50 form a conductive path for current flow between the shaft 122 and the housing 120.

[0060] Furthermore, the aforementioned drive unit 200 is one example of the application of the conductive sealing device 2, but its application is not limited to this. For example, in addition to battery electric vehicles (BEVs), the conductive sealing device 2 can also be used in drive units of electric vehicles (EVs) such as hybrid electric vehicles (HVs) and fuel cell vehicles (FCVs). In electric vehicles (EVs) and other vehicles equipped with electric motors, the induced current generated by the motor can sometimes generate electromagnetic noise. In addition, the switching operation of the inverter that controls the current supplied to the electric motor or other motors, or the induced voltage of the motor itself, can also sometimes generate electromagnetic noise. As described above, the conductive sealing device 2 forms a conductive path, allowing the electromagnetic noise transmitted to the shafts 110 and 122 to flow to the housing 120. This prevents communication failures or malfunctions of electronic equipment and prevents electrolytic corrosion of metal parts such as bearings.

[0061] The conductive sealing device 2 is used in the same way as the conductive structure 1, and performs the same function and achieves the same effect.

[0062] The conductive resin composition of the present invention will now be described. As an example, as described above, the conductive resin composition forms a conductive component 10 for forming a conductive path in the application object.

[0063] As described above, the conductive resin composition contains a fluoropolymer, a conductive material, and a conductive wear-resistant material. Furthermore, the fluoropolymer is polytetrafluoroethylene (PTFE). The conductive wear-resistant material is, for example, coke. Specifically, the conductive wear-resistant material is powdered coke. Additionally, the conductive wear-resistant material includes, for example, graphite, carbon nanotubes, carbon fibers, etc. That is, the conductive wear-resistant material can be, for example, one or more selected from coke, graphite, carbon nanotubes, carbon fibers, etc. In the conductive resin composition, coke is used as the conductive wear-resistant material. The conductive material is, for example, carbon particles. Specifically, the conductive material is, for example, carbon black such as Ketjen black.

[0064] The content of the conductive wear-resistant material is, for example, 10 vol% to 30 vol%. Furthermore, the content of the conductive material is 1 wt% to 8 wt%.

[0065] The conductive resin composition uses polytetrafluoroethylene as the base resin and contains, in addition to the conductive material, a conductive wear-resistant material as an additive. Therefore, the conductivity and durability of the conductive component 10 formed from the conductive resin composition are improved. This is because by incorporating a conductive wear-resistant material as an additive in addition to the conductive material into the conductive resin composition, the elongation of the conductive component 10 can be increased by at least 10% while improving conductivity. Therefore, in use, the conductive component 10 contacts the outer peripheral surface 110a of the shaft 110 with a lower elastic modulus and deforms with lower elasticity according to the eccentricity of the shaft 110. This suppresses wear caused by sliding of the conductive component 10 relative to the shaft 110. Therefore, the wear resistance and durability of the conductive component 10 are improved. Furthermore, the increased elongation of the conductive component 10 formed from the conductive resin composition allows it to expand without damage according to the diameter of the outer peripheral surface 110a of the inserted shaft 110 and deform without damage according to the eccentricity of the shaft 110. Thus, the durability of the conductive component 10 formed from the conductive resin composition is improved. Furthermore, since the elongation of the conductive component 10 is increased by at least 10%, when the conductive component 10 is molded from the conductive resin composition, the conductive component 10 is less prone to cracking or other damage during demolding.

[0066] Example The invention will be described in more detail below based on embodiments. However, the invention is not limited to the embodiments described below.

[0067] (Examples 1-3, Comparative Examples 1-6) The raw materials shown in Table 1 were blended to obtain a conductive resin composition. Next, the blended conductive resin composition was molded to produce a conductive component. The molding process employed a known PTFE molding method. Specifically, the blended raw materials were filled into a molding die, compressed and pre-formed, and the pre-formed body was sintered to obtain a molded body (blank). This molded body was then processed to obtain the conductive component. The conductive components in Examples 1-3 were conductive components 10, and the conductive components in Comparative Examples 1-6 were conductive components with the same shape as conductive component 10.

[0068] Details of the raw materials used in Examples 1-3 and Comparative Examples 1-6 are as follows.

[0069] (PTFE) INOFLON 640 (product name) (manufactured by GUJARAT FLUOROCHEMICALS LTD) (wear-resistant materials) CMW-350 (manufactured by Chuetsu Graphite Industry Co., Ltd.) (Conductive materials) VULCAN XC72 (made by Cabot Corporation) In addition, the surface resistivity of Examples 1-3 and Comparative Examples 1-6 was measured and their characteristics were evaluated. The surface resistivity was measured using the four-probe method. Figure 8 This diagram schematically illustrates the method of measuring surface resistivity using the four-probe method. In the four-probe method measurement, the applied voltage can be any value among 1V, 2V, and 5V. Furthermore, as a characteristic evaluation, the tensile strength and elongation of Examples 1-3 and Comparative Examples 1-6 were measured, and the 10% elongation stress was measured. The tensile strength and 10% elongation stress were measured at room temperature using a tensile test according to ASTM D638. Therefore, in the tensile strength and 10% elongation stress measurements, the shapes of Examples 1-3 and Comparative Examples 1-6 were set according to ASTM D638. Additionally, the 10% elongation stress is the stress generated when Examples 1-3 and Comparative Examples 1-6 are elongated by 10%. Table 1 shows the measurement results and characteristic evaluation results of the surface resistivity of Examples 1-3 and Comparative Examples 1-5. Furthermore, the conductive resin composition of Comparative Example 6 could not be molded into a conductive part. Therefore, there were no surface resistivity measurement results and characteristic evaluation results for Comparative Example 6. Furthermore, the surface resistivity of Comparative Example 1 could not be measured.

[0070] Table 1 As shown in Table 1, the measured surface resistivity values ​​of Examples 1-3 and Comparative Examples 2-5 indicate that the higher the content of conductive material, the lower the surface resistivity. Therefore, in Comparative Examples 1-6, which do not contain conductive wear-resistant materials, it is necessary to increase the content of conductive material to reduce the surface resistivity. However, the conductive resin composition of Comparative Example 6, which contains 30 wt% conductive material, cannot be molded into a conductive part. Thus, it can be concluded that in conductive resin compositions (Comparative Examples 1-6) that do not contain conductive wear-resistant materials, it is impossible to mold highly conductive parts with a surface resistivity of less than 10 Ω as measured by the four-probe method.

[0071] On the other hand, it is known that in Examples 1 to 3, which contain a conductive wear-resistant material, even conductive resin compositions capable of reducing surface resistivity can be molded into conductive parts 10. Furthermore, it is known that Examples 1 to 3 can achieve lower surface resistivity than Comparative Examples 2 to 5. Moreover, it is known that Examples 2 and 3 can achieve a surface resistivity of 10 Ω or less as measured by the four-probe method. Thus, the conductive resin composition according to embodiments of the present invention, which contains a conductive wear-resistant material in addition to a conductive material, can reduce surface resistivity and improve the conductivity of the conductive part 10 while enabling it to be molded.

[0072] Furthermore, as shown in Table 1, the elongation of Examples 1-3 is less than that of Comparative Examples 1-5, but their elongation exceeds 10%. That is, the conductive components 10 of Examples 1-3 have an elongation characteristic exceeding 10%. It is considered that even if demolding during the molding of the conductive component 10 requires deformation of the molded conductive component 10, as long as a 10% deformation can be achieved, the molded conductive component 10 can be demolded without damage. Therefore, it can be seen that although the elongation characteristic of the conductive components 10 of Examples 1-3 is reduced, the conductive components 10 of Examples 1-3 can still maintain an elongation characteristic that allows for demolding without damage. Furthermore, as shown in Table 1, the 10% elongation stress of Examples 1-3 is lower than that of Comparative Examples 1-5. Within a deformation range of at least 10%, the conductive components 10 of Examples 1-3 are more prone to deformation than the conductive components of Comparative Examples 1-5. That is, it can be seen that the conductive components 10 of Examples 1-3 are easier to demold than the conductive components of Comparative Examples 1-5. Thus, the conductive resin composition according to the embodiments of the present invention can suppress the significant reduction in the elongation characteristics of the molded conductive component 10, maintain the elasticity required for molding, and improve the moldability of the conductive component 10.

[0073] Furthermore, as shown in Table 1, a comparison of the 10% elongation stress in Examples 1-3 reveals that the higher the content of conductive material, the lower the 10% elongation stress. That is, it can be seen that in Examples 1-3, the easier it is to achieve 10% deformation, the higher the conductivity. Thus, the conductive resin composition according to the embodiments of the present invention can improve both the conductivity and moldability of the molded conductive component 10.

[0074] Furthermore, as described above, the conductive resin compositions of Examples 1-3 can suppress a significant decrease in the elongation characteristics of the molded conductive component 10. Therefore, in use, the conductive component 10 of Examples 1-3 undergoes elastic deformation and contacts the outer peripheral surfaces 110a and 122a of the shafts 110 and 122, and undergoes elastic deformation according to the eccentricity of the shaft 110. Furthermore, the conductive resin compositions of Examples 1-3 can expand without damage according to the diameter of the outer peripheral surfaces 110a and 122a of the inserted shafts 110 and 122, and can deform without damage according to the eccentricity of the shafts 110 and 122.

[0075] Furthermore, as described above, the 10% elongation stress of Examples 1-3 is lower than that of Comparative Examples 1-5. Within a deformation range of at least 10%, the conductive components 10 of Examples 1-3 have a smaller elastic modulus, are more flexible, and are more prone to elastic deformation compared to the conductive components of Comparative Examples 1-5. Therefore, the clamping force of the conductive components 10 of Examples 1-3 on the shafts 110 and 122 is lower than that of the conductive components of Comparative Examples 1-5 on the shafts 110 and 122. As a result, the wear amount of the conductive components 10 of Examples 1-3 due to sliding relative to the shafts 110 and 122 is less than that of the conductive components of Comparative Examples 1-5 due to sliding relative to the shafts 110 and 122. Thus, the conductive resin composition according to the embodiments of the present invention can improve the wear resistance and durability of the molded conductive components 10. Furthermore, the conductive components 10 of Examples 1-3 are more prone to deformation due to the eccentricity of shafts 110 and 122 compared to the conductive components of Comparative Examples 1-5, and are less likely to be damaged due to the eccentricity of shafts 110 and 122. Thus, the conductive resin composition according to the embodiments of the present invention can improve the conformability of the molded conductive component 10 to shafts 110 and 122, and improve the durability of the molded conductive component 10. Furthermore, the conductive components 10 of Examples 1-3 are more prone to expansion during the insertion of shafts 110 and 122 than the conductive components of Comparative Examples 1-5, and are less likely to be damaged due to the insertion of shafts 110 and 122. Thus, the conductive resin composition according to the embodiments of the present invention can improve the conformability of the molded conductive component 10 to the diameter of shafts 110 and 122, and improve the durability of the molded conductive component 10.

[0076] Furthermore, as shown in Table 1, for example, it can be seen that Embodiments 2 and 3 can set the surface resistivity measured by the four-probe method to below 10Ω.

[0077] As described above, the conductive resin compositions and conductive components 10 of Examples 1 to 3 can improve durability, reduce surface resistivity, and improve the conductivity of the conductive components 10.

[0078] Furthermore, the conductive resin compositions of Examples 1-3 can maintain a moderate tensile strength of the conductive component 10 and a moderate clamping force of the conductive component 10 on the shafts 110 and 122. This suppresses wear and permanent deformation of the conductive component 10. In this respect, the conductive resin compositions of Examples 1-3 can also improve the durability of the conductive component 10. Moreover, since wear and permanent deformation of the conductive component 10 can be suppressed, there is no need to provide a conductive lubricant between the conductive component 10 and the shafts 110 and 122. Therefore, there is no lubricant that could become a resistance in the conductive path between the shafts 110 and 122 and the housings 111 and 120, and the decrease in conductivity of the conductive structure 1 and the conductive sealing device 2 during use can be suppressed.

[0079] In addition, for example, Figure 4 , Figure 7 As shown, by fitting the retaining member 20 into the shaft hole 113 of the housing 111, the conductive structure 1 can be installed around the shaft 110. Thus, the installation of the conductive structure 1 only requires an annular space surrounding the outer peripheral surface 110a of the shaft 110. Even when there is space between the outer peripheral surface 110a of the shaft 110 and the inner peripheral surface 113a of the shaft hole 113 for installing the conductive structure 1, the conductive structure 1 can be installed in the shaft hole 113, thus eliminating the need for additional space in the housing 111 for installing the conductive structure 1. Furthermore, even when there is no space between the outer peripheral surface 110a of the shaft 110 and the inner peripheral surface 113a of the shaft hole 113 for installing the conductive structure 1, since the cross-section of the conductive structure 1 is small, only a small annular space needs to be provided in the inner peripheral surface 113a of the shaft hole 113 for installation. Thus, the space required for the installation of the conductive structure 1 can be reduced, saving space. The same applies to the conductive sealing device 2.

[0080] As described above, the conductive resin composition, conductive slider, and conductive structure of the present invention can improve both conductivity and durability.

[0081] The present invention has been described above through the above embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. As will be understood from the claims, methods in which such modifications or improvements have been made may also be included within the technical scope of the present invention.

[0082] The embodiments described above are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the above embodiments do not limit the application of the invention; any object can be used as an application. The constituent elements, their configurations, materials, conditions, shapes, and dimensions, etc., provided in the above embodiments are not limited to the examples and can be appropriately modified. For example, the invention includes deviations arising during the implementation process, such as manufacturing tolerances. Moreover, within the scope of technical non-contradiction, the constituent elements shown in different embodiments can be partially substituted or combined with each other. Furthermore, to achieve at least a portion of the above-mentioned problems and effects, the constituent elements can be appropriately and selectively combined.

[0083] For example, the outer peripheral end 10b of the conductive member 10 can be shaped as a straight portion extending along a straight line, rather than being circular. For example, the outer peripheral end 10b of the conductive member 10 can be rectangular. Furthermore, an adhesive can be used to bond the conductive member 10 to the retaining members 20, 50, or the elastomer portion 40. In this case, the adhesive is applied to avoid resistance that would become a conductive path. And, in this case, a conductive adhesive is used.

[0084] Symbol Explanation 1 Conductive structure, 2 Conductive sealing device, 3 Conductive structural part, 10 Conductive component, 10a Inner peripheral end, 10b Outer peripheral end, 11 Contact side, 12 Back side, 13 Inner peripheral end, 14 Outer peripheral end, 20 Retaining component, 21 Inner retaining component, 22 Fitting part, 22a Outer peripheral surface, 23 Retaining part, 25 Outer retaining component, 26 Fitting part, 26a Inner peripheral surface, 27 Retaining part, 27a Side, 28 Pressing part, 30 Reinforcing ring, 31 Cylindrical part, 32 Circular part, 40 Elastomer part, 41 Sealing lip, 41a Protrusion, 42 Base, 43 Gasket part, 43a Outer peripheral surface, 44 Cover part, 44a Outer peripheral end, 45 Fitting surface, 46 Recess, 47 Retaining surface, 47a Recess, 50 51 Retaining component, 51 Fitting part, 51a Outer peripheral surface, 51b Inner peripheral surface, 51c End, 52 Retaining part, 52a, 52b Side surface, 53 Protrusion, 100, 200 Drive unit, 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 section, 112, 123 Bearing, 113, 124, 126 Shaft hole, 113a, 124a, 126a Inner peripheral surface, 125, 127 Oil seal, X-axis.

Claims

1. A conductive resin composition comprising a fluororesin, a conductive material, and a wear-resistant material with conductive properties. The fluororesin is polytetrafluoroethylene.

2. The conductive resin composition according to claim 1, wherein, The wear-resistant material is coke.

3. The conductive resin composition according to claim 1 or 2, wherein, The conductive material is carbon particles.

4. The conductive resin composition according to claim 3, wherein, The conductive material is carbon black.

5. A conductive slider, which is annular about an axis x, is formed of a conductive resin composition, said conductive resin composition containing a fluororesin, a conductive material, and a wear-resistant material having conductivity, wherein the fluororesin is polytetrafluoroethylene.

6. The conductive slider according to claim 5, wherein, The wear-resistant material is coke.

7. The conductive slider according to claim 5 or 6, wherein, The conductive material is carbon particles.

8. The conductive slider according to claim 7, wherein, The conductive material is carbon black.

9. The conductive slider according to claim 5, wherein, A shaft for rotation about the axis is inserted.

10. A conductive structure, mounted between a shaft and a hole through which the shaft passes, comprising: A conductive slider, wherein the conductive slider is a component arranged in a ring around an axis; and A support component, which is annular about the axis and supports the conductive sliding body. The conductive slider is formed from a conductive resin composition. The conductive resin composition contains fluororesin, conductive materials, and wear-resistant materials with conductive properties. The fluororesin is polytetrafluoroethylene.

11. The conductive structure according to claim 10, wherein, The wear-resistant material is coke.

12. The conductive structure according to claim 10 or 11, wherein, The conductive material is carbon particles.

13. The conductive structure according to claim 12, wherein, The conductive material is carbon black.

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