Shaft grounding device for electric motor

Abstract

A shaft grounding device of the present invention comprises: a first plate having an opening formed in the center thereof; a second plate coupled to the first plate and forming a plurality of channels on one side facing the first plate; and a conductive brush press-fitted and fixed to the channels, and having both ends fixed in a state of being exposed to the opening so as to be in contact with a shaft passing through the opening.

Description

Shaft grounding device for electric motor

[0001] The present invention relates to a shaft grounding device that prevents electrical corrosion of a bearing by grounding the current induced in the shaft of a motor controlled by a VFD (Variable Frequency Device) to induce it into the motor housing.

[0002] Due to the recent trend of strengthening environmental regulations, eco-friendly electric vehicles such as electric cars or fuel cell cars are attracting attention, and in eco-friendly vehicles, electric motors (hereinafter referred to as “drive motors”) are used as a driving force that obtains rotational power from electric energy instead of internal combustion engines such as conventional engines.

[0003] The drive motor, which is the power source of an eco-friendly vehicle, includes a motor housing, a stator fixedly installed inside the motor housing, and a rotor that is positioned with a certain gap from the stator and rotates around a shaft, which is a drive axis.

[0004] The drive motor is driven by a variable frequency drive (VFD), which induces a parasitic voltage in the rotating shaft of the drive motor. This voltage is then transmitted to the housing through the bearing that supports the shaft. However, this process causes a potential difference between the inner and outer rings of the bearing, which in turn causes corrosion of the bearing due to the discharge mechanism within the bearing, which can damage the bearing and seriously affect the durability of the motor.

[0005] To solve this problem, a shaft ground ring (SGR) that conducts current between the motor housing and the rotating shaft is installed between the shaft and the housing to reduce the shaft voltage.

[0006] Fig. 1 is a photograph of a conventional shaft grounding ring.

[0007] Figure 1 (a) is a structure in which a thin filament or yarn-shaped conductive material is fixed between housing plates, and Figure 1 (b) is a structure in which a conductive material is inserted into the housing in bundle units.

[0008] When a shaft ground ring of this structure is used for a long time, there is a possibility that the conductive material may come off, and in particular, in the case of a structure in which the conductive material is fixed between the housing plates, oil may flow between the housing and the conductive material, which may reduce the electrical conductivity between the housing and the conductive material, and there is a problem in that the area or number of housings must be increased in order to increase the quantity of conductive material.

[0009] In this case, if the conductive material is detached, not only will the grounding function of the shaft be reduced, but the detached material may circulate inside the motor, causing accidents such as short circuits.

[0010] One aspect of the present invention is to provide a shaft grounding device capable of preventing damage to a bearing due to shaft voltage generated from a driving motor.

[0011] One aspect of the present invention is to provide a shaft grounding device having an improved structure that can prevent a conductive brush from being detached from the shaft grounding device and prevent foreign substances from entering between a ring-shaped plate that secures the shaft grounding device and the conductive brush.

[0012] One aspect of the present invention is to provide a shaft grounding device in which a bundle-shaped conductive brush can stably maintain contact with a shaft in an environment where vibration occurs due to shaft rotation, thereby maintaining electrical conductivity.

[0013] A shaft grounding device according to one embodiment of the present invention comprises a structure including a first plate having an opening formed in the center; a second plate coupled to the first plate to form a plurality of channels on one side facing the first plate; and a conductive brush press-fitted into the channel and fixed with both ends exposed to the opening so as to be in contact with a shaft passing through the opening.

[0014] According to one embodiment of the present invention, the first plate may have a plurality of channel grooves formed in a negative manner along the inner circumferential direction so that a conductive brush can be press-fitted on one surface facing the second plate.

[0015] According to one embodiment of the present invention, the channel groove may be formed to be curved in a U-shape with a horizontal cross-sectional area that is inverted upside down.

[0016] According to one embodiment of the present invention, the channel groove includes a first channel groove and a third channel groove formed in a first direction and in contact with the opening; and a second channel groove formed in a direction perpendicular to the first direction and connecting the first channel groove and the third channel groove to each other, and the second channel groove may be formed to have a width equal to or smaller than the width of the first channel groove or the third channel groove.

[0017] According to one embodiment of the present invention, the second plate may be formed with a convex, closely fitting projection that protrudes in a raised manner on one surface facing the first plate so as to be inserted into a channel groove, and the height of the projection may be formed to have a size relatively smaller than the depth of the channel groove.

[0018] According to one embodiment of the present invention, the conductive brush can be pressed into the channel in a bent state such that the first end and the second end are exposed to the same length toward the shaft.

[0019] According to one embodiment of the present invention, the conductive brush can be formed by bundling conductive fiber strands made of at least one of carbon fiber, stainless steel, copper, conductive plastic, and conductive rubber.

[0020] According to one embodiment of the present invention, the conductive brush may be formed in the form of a bundle in which a conductive thin plate is wound around the central portion of conductive fiber strands. The conductive thin plate may be made of copper, aluminum, or the like, which has a thin thickness and excellent conductivity. This is to prevent the conductive fiber strands from coming off during the process of using the shaft grounding device.

[0021] According to one embodiment of the present invention, the first plate includes a plurality of first fastening holes formed along a circumferential direction and formed between adjacent channel grooves, the second plate includes a second fastening hole formed at a position facing the first fastening hole, and the first plate and the second plate can be laminated and joined by a fastening hole passing through the first fastening hole and the second fastening hole.

[0022] According to one embodiment of the present invention, the first plate includes an annular protruding rim formed to protrude at a predetermined height along an outer circumference on one surface facing the second plate, and the second plate is formed to have a smaller radius than the first plate and can be press-fitted and fixed into the inside of the protruding rim.

[0023] According to one embodiment of the present invention, the first plate may include a plurality of protruding walls that protrude toward the opposing second plate and are arranged at a constant interval along the circumferential direction; and a hooking projection that is respectively arranged between the adjacent protruding walls and protrudes at a position adjacent to the edge of the opening so that a conductive brush can be hooked and supported.

[0024] According to one embodiment of the present invention, a side wall block interposed between the first plate and the second plate may be further included.

[0025] According to one embodiment of the present invention, the side wall block may be positioned adjacent to the outer edge of the first plate between the adjacent protruding walls, but may be positioned at a point spaced apart from the catch by a first distance to form a channel.

[0026] According to one embodiment of the present invention, the stumbling block may be spaced apart from the protruding walls located on the left and right sides by a second distance that is the same as each other, and the first distance may have a size that is equal to or smaller than the second distance.

[0027] Another embodiment of the present invention may include an electric motor comprising a housing; a shaft; and the aforementioned shaft grounding device radially mounted between the housing and the shaft and in radial contact with the shaft.

[0028] According to one embodiment of the present invention, damage to a bearing due to electrolysis can be prevented by effectively grounding the shaft voltage generated from a driving motor.

[0029] According to one embodiment of the present invention, by pressing and fixing a conductive brush pressed into a channel provided between a first plate and a second plate with a close protrusion, the inflow of foreign substances is blocked, fiber strands of the conductive brush are prevented from coming off, and a stable state of contact with the shaft is maintained.

[0030] Fig. 1 is a photograph of a conventional shaft grounding ring.

[0031] Figure 2 is a perspective view of a joint of a shaft grounding device according to a first embodiment of the present invention.

[0032] Figure 3 is an exploded perspective view of the shaft grounding device of Figure 2.

[0033] Figure 4 is a plan view of the first plate of Figure 2.

[0034] Figure 5 is a plan view of the second plate of Figure 2.

[0035] Fig. 6 is a side cross-sectional view of the shaft grounding device of Fig. 2.

[0036] Fig. 7 is a plan view of the shaft grounding device of Fig. 2.

[0037] FIG. 8 is an explanatory diagram of another method of joining between a first plate and a second plate according to a first embodiment of the present invention.

[0038] Figure 9 is a perspective view of a joint of a shaft grounding device according to a second embodiment of the present invention.

[0039] Fig. 10 is an exploded perspective view of the shaft grounding device of Fig. 9.

[0040] Fig. 11 is a side cross-sectional view of the shaft grounding device of Fig. 9.

[0041] Fig. 12 is a plan view of the shaft grounding device of Fig. 9.

[0042] Figure 13 is a schematic drawing showing a state in which a shaft grounding device according to an embodiment of the present invention is installed on a motor.

[0043] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description have been omitted for clarity of description, and the same reference numerals designate identical or similar components throughout the specification.

[0044] Additionally, throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0045]

[0046] Example 1

[0047] FIG. 2 is a perspective view of a shaft grounding device according to a first embodiment of the present invention, FIG. 3 is an exploded perspective view of the shaft grounding device of FIG. 2, FIG. 4 is a plan view of the first plate of FIG. 2, FIG. 5 is a plan view of the second plate of FIG. 2, and FIG. 6 is a side cross-sectional view of the shaft grounding device of FIG. 2.

[0048] A shaft grounding device (10) according to a first embodiment of the present invention may include a first plate (100), a second plate (200), a conductive brush (300), and a fastener that connects the first plate (100) and the second plate (200).

[0049] The shaft grounding device (10) of the present invention is a device that is electrically connected to the shaft (S) of the motor and grounded to reduce the shaft voltage or parasitic voltage generated in the motor shaft (S).

[0050]

[0051] Plate 1

[0052] The first plate (100) is configured as a ring-shaped plate that is fastened to the motor housing (H) and may be made of a conductive material for grounding. For example, the first plate (100) may be manufactured from a conductive metal (e.g., stainless steel), or aluminum, copper, bronze, gold, or a combination thereof.

[0053] The first plate (100) may have a first opening (101) formed in the center through which a shaft (S) may pass, and a plurality of first fastening holes (102) may be formed along the circumferential direction of the first opening (101). The first fastening hole (102) may be formed in a structure that can be fastened with a fastening member so that the second plate (200) can be laminated and fastened to the first plate (100). The structure of the first plate (100) and the second plate (200) connected by the fastening member will be described later.

[0054] The first plate (100) may have a channel groove (150) engraved on one side (100a) facing the second plate (200) so that a conductive brush (300) can be installed therein.

[0055] The above channel groove (150) is a groove having a shape that is recessed to a predetermined depth (d) from one side (100a) of the first plate (100), and a plurality of such grooves may be formed along the inner circumferential direction of the first plate (100). The above channel groove (150) is a structure for press-fitting a conductive brush (300) in a state in which the first plate (100) and the second plate (200) are laminated and bonded.

[0056] The above channel grooves (150) may be provided in multiple numbers and arranged at a predetermined distance apart along the circumferential direction, and the intervals between adjacent channel grooves (150) may be the same.

[0057]

[0058] *A first fastening hole (102) may be positioned between adjacent channel grooves (150) in the first plate (100), and a structure in which the first fastening hole (102) is positioned and a structure in which the first fastening hole (102) is not positioned may be arranged alternately.

[0059] The above channel home (150) can be formed to be curved in a U-shape with a horizontal cross-sectional area that is inverted upside down.

[0060] The curved shape of the above channel groove (150) is intended to allow both ends (301, 302) of the conductive brush (300) to face the first opening (101) by placing the conductive brush (300) in a bent state in the channel groove (150). The both ends (301, 302) of the conductive brush (300) are exposed to the first opening (101) and can come into contact with the shaft (S).

[0061] The above channel home (150) may include a first channel home (151), a second channel home (152), and a third channel home (153).

[0062] Specifically, the first channel groove (151) and the third channel groove (153) are portions that are connected in a state of contact with the first opening (101), and the second channel groove (152) is a portion that connects the first channel groove (151) and the third channel groove (153). The first channel groove (151) and the third channel groove (153) may be formed to be long in the y-axis direction or formed in a radial direction, and the second channel groove (152) may be formed to be long in the left-right direction (x-axis direction).

[0063] The corner portions located at the portion where the first channel groove (151) and the second channel groove (152) are connected, and the portion where the second channel groove (152) and the third channel groove (153) are connected, respectively, can be formed smoothly with a constant curvature.

[0064] The first channel groove (151) may be formed with a width of W1, the second channel groove (152) with a width of W2, and the third channel groove (153) with a width of W3. In this case, the width (W2) of the second channel groove (152) may be formed to a size equal to or smaller than the width (W1) of the first channel groove or the width (W3) of the third channel groove (153).

[0065] This structure is intended to ensure that the plurality of conductive fiber strands constituting the conductive brush (300) are pressed into the channel groove (150) and that the conductive brush (300) is stably fixed.

[0066] Accordingly, even if the shaft grounding device is used for a long time, the conductive fiber strands can be prevented from coming off, thereby maintaining the grounding function of the shaft at a constant level, and accidents such as short circuits that may occur due to the coming off of conductive materials can be prevented.

[0067] The above channel groove (150) can increase the adhesive strength of the conductive brush (300) that is seated in the channel groove (150) by applying an adhesive to the surface. This can correspond to an auxiliary means for stably seating the conductive brush (300).

[0068]

[0069] Second plate

[0070] The second plate (200) is a ring-shaped plate that is coupled to the first plate (100) and may be made of a conductive material. For example, the first plate (100) may be made of a conductive metal (e.g., stainless steel), or aluminum, copper, bronze, gold, or a combination thereof.

[0071] The second plate (200) may have the same radius as the first plate (100). Under this structure, the outer surface of the structure in which the second plate (200) is laminated and bonded to the first plate (100) can be formed smoothly.

[0072] The second plate (200) may have a second opening (201) formed in the center through which a shaft (S) may pass, and a plurality of second fastening holes (202) may be formed along the circumferential direction.

[0073] The second plate (200) can be coupled to face one side (100a) of the first plate (100) on which a channel groove (150) is formed. When the second plate (200) is coupled to the first plate (100), a channel (C) capable of accommodating a conductive brush (300) can be provided between the one side (200a) of the second plate (200) facing the channel groove (150).

[0074] The second plate (200) may have a raised protrusion (250) formed on one side (200a) facing the first plate (100).

[0075] The above-mentioned close protrusion (250) has a shape that protrudes from one side (200a) of the second plate (200) at a predetermined height (h), and a plurality of the protrusions may be formed along the inner circumferential direction of the second plate (200). The above-mentioned close protrusion (250) is a structure for increasing the close force of the conductive brush (300) accommodated in the channel (C).

[0076] Accordingly, the above-mentioned close protrusion (250) can be formed in a shape corresponding to the channel groove (150) so that it can be inserted into the channel groove (150) when the first plate (100) and the second plate (200) are combined.

[0077] For example, when the channel groove (150) is formed to be curved in a U-shape that is inverted upside down, the contact protrusion (250) can be formed in a U-shape that is inverted upside down so that it can be inserted into the channel groove (150).

[0078] Meanwhile, the above-mentioned close protrusion (250) can be interpreted as including not only a U-shape that is inverted upside down, but also various shapes for increasing close adhesion by pressing the conductive brush (300) accommodated in the channel (C).

[0079] Since the above-mentioned close protrusion (250) is formed so that the protrusion height (h) is smaller than the depth (d) of the channel groove (150), the close protrusion (250) can be inserted into the channel groove (150) even when the conductive brush (300) is seated in the channel groove (150).

[0080] The above protrusion height (h) can be formed to a minimum size that can maintain a fixed state for the conductive brush (300) pressed into the channel groove (150) when the first plate (100) and the second plate (200) are combined.

[0081] Accordingly, the protrusion height (h) may vary depending on the specifications of the conductive brush (300) pressed into the channel groove (150), for example, the number of conductive fiber strands constituting the conductive brush, the cross-sectional size of the conductive fiber strands, etc.

[0082] Through this structure, when the first plate (100) and the second plate (200) are combined, the contact protrusion (250) is pressed against the conductive brush (300) pressed into the channel, thereby increasing the contact force and stably maintaining the fixed state even when the shaft of the motor vibrates.

[0083]

[0084] conductive brush

[0085] The above conductive brush (300) can be formed by bundling strands made of at least one of carbon fiber, stainless steel, and conductive plastic.

[0086] The above conductive brush (300) can be formed in the form of a bundle in which a conductive thin plate (310) is wound around the central portion of conductive fiber strands. Copper, aluminum, etc., which are thin and have excellent conductivity, can be used as the conductive thin plate. This is to prevent the conductive fiber strands from coming off during the process of using the shaft grounding device.

[0087] For example, the conductive brush (300) may be formed in the form of a bundle of carbon fiber strands having a diameter of approximately 5 to 10 μm. Preferably, considering the functional aspects of grounding (reducing friction, preventing foreign matter penetration, and maintaining rigidity), the carbon fiber strands may have a diameter of 6 to 8 μm.

[0088] The conductive brush (300) can be press-fitted and fixed within the channel (C), and both ends (301, 302) of the conductive brush (300) are exposed to the opening (101), and the both ends (301, 302) can come into contact with a shaft (S) penetrating the opening (101).

[0089] To this end, the conductive brush (300) is press-fitted and fixed within the channel (C) in a bent state, and the length of the first end (301) exposed and the length of the second end (302) exposed may be the same.

[0090] Referring to FIG. 6, the channel (C) into which the conductive brush (300) is press-fitted and fixed can have a cross-section formed in a rectangular shape.

[0091] The cross-section of the above-mentioned channel (C) having a rectangular shape may have a horizontal length of dh and a vertical length of W2, where dh is the difference between the depth (d) of the channel groove and the height (h) of the contact protrusion, and W2 means the width (W2) of the second channel groove (152).

[0092] The cross-sectional size of the above channel (C) can vary depending on the specifications of the conductive brush (300) pressed into the channel (C), and specifically, can vary depending on the number of conductive fiber strands constituting the conductive brush (300), the diameter of the conductive fiber strands, etc.

[0093]

[0094] Joint structure of the first and second plates

[0095] According to one embodiment of the present invention, the first plate (100) and the second plate (200) can be laminated and joined by a fastener.

[0096] The first plate (100) is formed with a plurality of first fastening holes (102) that penetrate the first plate (100), and screw threads may be formed on the inner circumference of the first fastening holes (102). The second plate (100) may be formed with a plurality of second fastening holes (202) at positions corresponding to the first fastening holes (102), and screw threads may be formed on the inner circumference of the second fastening holes (202).

[0097] In a state where the first plate (100) and the second plate (200) are laminated, a fastening bolt (B) having threads formed on the surface passes through the second fastening hole (202) and is fastened to the first fastening hole (102), so that the first plate (100) and the second plate (200) can be joined.

[0098] Regarding the present invention, the present specification describes a structure in which the first fastening hole (102) of the first plate (100) penetrates the first plate (100), but it may also include a structure that includes not only a penetrating structure like the first fastening hole (102), but also a structure that is formed in the form of a groove in the first plate (100) like a fastening groove.

[0099] Meanwhile, according to one embodiment of the present invention, the first fastening hole (102) and the second fastening hole (202) may be configured to have a smooth surface without forming screw threads on the inner circumference thereof. In this structure, after the fastening pin (P) is inserted through the first fastening hole (102) and the second fastening hole (202), the protruding end is deformed (crushed) by punching, thereby fixing the first plate (100) and the second plate (200) in a stacked state.

[0100]

[0101] FIG. 8 is an explanatory diagram of another method of joining between a first plate and a second plate according to a first embodiment of the present invention.

[0102] Referring to FIG. 8, the second plate (200) can be joined to the first plate (100) in a press-fit manner.

[0103] The first plate (100) and the second plate (200) are both annular plates having an opening formed in the center, and the second plate (200) may be formed to have a smaller radius than the first plate (100). The first plate (100) may have an annular protruding rim (180) formed along the outer edge at a predetermined height on one side (100a) facing the second plate (200).

[0104] Accordingly, the second plate (200) can be pressed into the inside of the protruding rim (180) and joined to the first plate (100).

[0105] Although the drawing (Fig. 8) shows a structure in which a fastening bolt (B) penetrates the first fastening hole (102) and the second fastening hole (202) and is fastened, the present invention can be interpreted as including both a fastening method by press-fitting and a double fastening method by press-fitting and a fastening bolt.

[0106]

[0107] Second Example

[0108] FIG. 9 is a perspective view of a shaft grounding device according to a second embodiment of the present invention, FIG. 10 is an exploded perspective view of the shaft grounding device of FIG. 9, FIG. 11 is a side cross-sectional view of the shaft grounding device of FIG. 9, and FIG. 12 is a plan view of the shaft grounding device of FIG. 9.

[0109] Referring to the drawing, a shaft grounding device according to a second embodiment of the present invention includes a first plate (1100), a second plate (1200), a conductive brush (1300), and a side wall block (1400).

[0110] A second embodiment of the present invention relates to another structure forming a channel between a first plate and a second plate, and compared to the first embodiment, there is a difference in that the first plate has a changed shape and the shaft grounding device further includes a side wall block as a configuration.

[0111] The first plate (1100) is a ring-shaped plate having a first opening (1101) formed in the center through which a shaft (S) can pass, and a protruding wall (1110) and a catch (1150) may be formed on one side (1100a) facing the second plate (1200).

[0112] The above protrusion wall (1110) is configured to support the second plate (1200) and form a channel together with the catch (1150) and the side wall block (1400) between the first plate (1100) and the second plate (1200).

[0113] The above protruding wall (1110) is formed to protrude toward the second plate (1200), and the upper surface (1110a) can be in surface contact with the second plate (1200). A first fastening hole (1112) for coupling with the second plate (1200) can be formed on the upper surface (1110a) of the above protruding wall (1110).

[0114] The above protrusion walls (1110) may be arranged in multiple numbers at regular intervals along the circumferential direction. When the first plate (1100) and the second plate (1200) are combined, a plurality of spaces (R) may be provided between the first plate (1100) and the second plate (1200), and each space (R) refers to a space provided between adjacent protrusion walls (1110).

[0115] The above-mentioned stumbling block (1150) forms a channel together with the protruding wall (1110) and the side wall block (1400), and is configured to support the conductive brush (1300) by hanging it so that the conductive brush (1300) can come into contact with the shaft (S).

[0116] The above-mentioned hooks (1150) are provided in multiple numbers, and each hook (1150) can be positioned adjacent to the edge of the first opening (1101) between adjacent protruding walls (1110). Specifically, the hook (1150) can be positioned adjacent to the edge of the first opening (1101), but can be positioned at an equal distance from the protruding walls (1110) located on both the left and right sides.

[0117] Specifically, the above-mentioned stumbling block (1150) is located adjacent to the edge of the first opening (1101), but may be located at the center point of two protruding walls (1110) located on the left and right sides.

[0118] The above-mentioned stumbling block (1150) is formed to protrude toward the second plate (1200), and the protruding height may be the same as the protruding height of the protruding wall (1110). The upper surface (1150a) of the above-mentioned stumbling block (1150) may be in surface contact with the second plate (1200).

[0119] The above-mentioned stud (1150) can support the conductive brush (1300) so that both ends (1301, 1302) of the conductive brush (1300) can come into contact with the shaft (S).

[0120] The above side wall block (1400) is configured to support the second plate (1200) and form a channel together with the aforementioned protrusion wall (1110) and catch (1150).

[0121] The above side wall blocks (1400) are provided in multiple numbers and are interposed between the first plate (1100) and the second plate (1200), and each side wall block (1400) can be positioned adjacent to the outer edge of the first plate (1100).

[0122] Specifically, the side wall block (1400) may be positioned between adjacent protruding walls (1110), but may be positioned at a point spaced apart from the stumbling block (1150) by a predetermined distance.

[0123] Here, when the distance at which the side wall block (1400) is spaced from the stumbling block (1150) is set as the first distance, and the distance between the stumbling block (1150) and the protruding wall (110) located on the left or right is set as the second distance, the first distance may be equal to or smaller than the second distance.

[0124] By controlling the width of the passage or channel through which the conductive brush is pressed through this structure, the press-fit fixing force can be increased, thereby stably maintaining the contact state of the conductive brush with the shaft in a vibration-generating environment and preventing the conductive fiber strands of the conductive brush from coming off.

[0125] The above side wall block (1400) can be formed in a hexahedral block shape, and the height of the side wall block (1400) can be the same as the protrusion height of the protrusion wall (1110), and can be formed long in the left and right directions so as to be in contact with the protrusion walls (1110) located on both sides.

[0126] The second plate (1200) is a ring-shaped plate having a second opening (1201) formed through the center thereof, and a plurality of second fastening holes (1202) for connection with the first plate (1100) may be formed along the circumferential direction. The first plate (1100) and the second plate (1200) may be connected in a stacked state by fastening members such as fastening bolts or fastening pins inserted into the first fastening holes (1112) and the second fastening holes (1202).

[0127]

[0128] The channel provided by the above-described configurations is described with reference to FIGS. 11 and 12.

[0129] When the first plate (1100) and the second plate (1200) are combined, if a side wall block (1400) is interposed in the space (R) provided between the protruding walls (1110a, 1110f), a passage or channel (C) into which a conductive brush (1300) can be pressed can be formed.

[0130] In the above channel (C), a conductive brush (1300) formed by bundling a plurality of carbon fiber strands is press-fitted and fixed, and the bent conductive brush (1300) is supported by wrapping around a stud (1150) so that both ends (1301, 1302) can come into contact with the shaft (S).

[0131]

[0132] Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the patent claims, the detailed description of the invention, and the attached drawings, and it is obvious that this also falls within the scope of the present invention.

Claims

1. A first plate having an opening formed in the center; A second plate coupled to the first plate to form a plurality of channels on one side facing the first plate; and A conductive brush which is press-fitted into the above channel and is fixed with both ends exposed to the opening so as to be in contact with a shaft penetrating the opening; A shaft grounding device including:

2. In paragraph 1, The above first plate, A plurality of channel grooves formed in a negative manner so that a conductive brush can be pressed into one surface facing the second plate are arranged along the inner circumferential direction. Shaft grounding device.

3. In paragraph 2, The above channel home is, The horizontal cross-section is formed in a curved U-shape with the top and bottom reversed. Shaft grounding device.

4. In paragraph 3, The above channel home is, A first channel groove and a third channel groove formed in a first direction and in contact with the opening; and a second channel groove formed in a direction perpendicular to the first direction and connecting the first channel groove and the third channel groove to each other. Including, The second channel groove is formed with a width equal to or smaller than the width of the first channel groove or the third channel groove. Shaft grounding device.

5. In paragraph 2, The above second plate, A convex, protruding, tight-fitting projection is formed on one side facing the first plate so that it can be inserted into the channel groove. The above protrusion height is formed to have a size relatively smaller than the depth of the channel groove. Shaft grounding device.

6. In paragraph 1, The above conductive brush is, The first end and the second end are bent toward the shaft so that the exposed lengths are the same and are pressed into the channel. Shaft grounding device.

7. In paragraph 1, The above conductive brush is, Formed by bundling conductive fiber strands made of at least one of carbon fiber, stainless steel, copper, conductive plastic, and conductive rubber, Shaft grounding device.

8. In paragraph 2, The first plate is formed in a plurality along the circumferential direction, and includes a first fastening hole formed between adjacent channel grooves, The second plate includes a second fastening hole formed at a position facing the first fastening hole, The first plate and the second plate are laminated and joined by a fastener passing through the first fastener hole and the second fastener hole. Shaft grounding device.

9. In paragraph 2, The above first plate, It includes an annular protruding rim formed to protrude at a predetermined height along the outer circumference on one side facing the second plate, The second plate is press-fitted and fixed to the inside of the protruding rim, Shaft grounding device.

10. In paragraph 1, The above first plate, A protruding wall formed to protrude toward the second plate facing it, and a plurality of protruding walls arranged at regular intervals along the circumferential direction; and A hook-up projection is formed at a position adjacent to the edge of the opening so that the conductive brush can be hooked and supported, and is respectively disposed between the adjacent protruding walls; Including, Further comprising a side wall block interposed between the first plate and the second plate, The above side wall block, A channel is formed at a point adjacent to the outer edge of the first plate between the adjacent protrusions, but spaced apart from the stud by a first distance. Shaft grounding device.

11. In paragraph 10, The above obstacle is, are spaced apart from the protruding walls located on both sides by a second distance equal to each other, The first distance has a size equal to or smaller than the second distance, Shaft grounding device.

12. Housing; shaft; A shaft grounding device according to claim 1, which is radially mounted between the housing and the shaft and is in radial contact with the shaft; An electric motor including:

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