Conductive device and electric machine

Abstract

The utility model provides a kind of electric conduction device and motor, the electric conduction device is used to connect the motor shaft ground of motor, electric conduction device includes: electric ring and carbon fiber conducting brush;Electric ring is arc sheet structure, electric ring is connected with the motor shell of motor, electric ring is set on the outside of motor shaft, the first end of carbon fiber conducting brush is connected with the inner surface of electric ring, the second end of carbon fiber conducting brush extends to the direction of motor shaft, and contact with motor shaft;Carbon fiber conducting brush, for connecting motor shaft and electric ring electricity, so that motor shaft is grounded through motor shell.The electric conduction device provided by the utility model uses the electric brush of long service life carbon fiber material, no maintenance is needed in the life cycle of motor, and because carbon fiber conducting brush uses carbon fiber material, no powder pollution grease in bearing in motor during motor operation process can be generated, can increase bearing service life, improve the reliability of motor.

Description

Technical Field

[0001] This application relates to the field of motor drive technology, and in particular to a conductive device and a motor. Background Technology

[0002] When a motor is driven by a variable-frequency drive (VFD), the sum of the three-phase output voltages of the VFD is not always zero. The voltage at which the sum of the three-phase voltages is not zero is the common-mode voltage. Due to the presence of high-frequency common-mode voltage and stray capacitance in the circuit, electrical discharge current, high-frequency circulating current, and shaft-to-ground current will be generated on the motor shaft. This will cause the motor bearings to discharge, leading to high-temperature seizure of the bearings and unexpected motor shutdown.

[0003] Currently, grounding carbon brushes are installed on the motor shaft to conduct the current generated by the motor shaft to the ground.

[0004] However, grounding carbon brushes have a short lifespan and require frequent replacement, resulting in high maintenance costs. Additionally, worn carbon brushes produce powder that contaminates the grease in the motor bearings, reducing bearing lifespan and leading to lower motor reliability. Utility Model Content

[0005] In view of this, this application provides a conductive device and an electric motor to at least partially solve the above-mentioned problems.

[0006] According to a first aspect of the embodiments of this application, a conductive device is provided for grounding the motor shaft of a motor. The conductive device includes: a conductive ring and a carbon fiber conductive brush; the conductive ring is an arc-shaped sheet structure, the conductive ring is connected to the motor housing of the motor, the conductive ring is sleeved on the outside of the motor shaft, a first end of the carbon fiber conductive brush is connected to the inner surface of the conductive ring, and a second end of the carbon fiber conductive brush extends in the direction of the motor shaft and contacts the motor shaft; the carbon fiber conductive brush is used to electrically connect the motor shaft to the conductive ring, so that the motor shaft is grounded through the motor housing.

[0007] In one possible implementation, the carbon fiber conductive brush includes: multiple sets of carbon fiber brushes, each set of carbon fiber brushes including one or more carbon fibers, the first end of each set of carbon fiber brushes being connected to the inner surface of the conductive ring, and the multiple sets of carbon fiber brushes being periodically distributed on the inner surface of the conductive ring, and the second end of each set of carbon fiber brushes being in contact with the motor shaft.

[0008] In one possible implementation, the conductive ring includes an upper fan ring, a lower fan ring, and a metal plate; the upper fan ring, the lower fan ring, and the metal plate are all arc-shaped sheet structures, the inner arc radius of the upper fan ring is equal to the inner arc radius of the lower fan ring, the outer arc radius of the upper fan ring is smaller than the outer arc radius of the lower fan ring, the metal plate is disposed between the upper fan ring and the lower fan ring, the upper fan ring, the metal plate, and the lower fan ring are connected by rivets, and the first end of the carbon fiber conductive brush is inserted into a blind hole in the metal plate.

[0009] In one possible implementation, the lower fan ring includes an arc-shaped, sheet-like protrusion structure. The inner arc radius of the protrusion structure is equal to the inner arc radius of the upper fan ring, and the outer arc radius of the protrusion structure is equal to the outer arc radius of the upper fan ring. A blocking structure is provided at the outer arc edge of the protrusion structure. The protrusion structure is configured to connect with the upper fan ring, and the metal plate is located between the upper fan ring and the protrusion structure. The blocking structure is configured to contact the outer arc surface of the upper fan ring.

[0010] In one possible implementation, the lower fan ring is connected to a bearing cover in the motor, wherein the bearing cover is used to fix the bearing, the bearing is sleeved on the outside of the motor shaft, and the bearing cover is located between the bearing and the conductive ring.

[0011] In one possible implementation, the lower fan ring and the bearing cover are limited by a stop.

[0012] In one possible implementation, the eccentricity between the multiple sets of carbon fiber brushes and the motor shaft is less than 0.15 mm.

[0013] In one possible implementation, the distance between the tip of the second end of the carbon fiber conductive brush and the axis of the motor shaft is D1 = D / 2 - δ, where D1 represents the distance between the tip of the second end of the carbon fiber conductive brush and the axis of the motor shaft, D represents the diameter of the motor shaft in the conductive ring sleeve area, and δ = 2 * n * π * D * 10 -6 , where n is used to characterize the rotational speed of the motor.

[0014] According to a second aspect of the present application, an electric motor is provided, comprising: an electric motor housing, an electric motor shaft, and a conductive device as described in the first aspect; the conductive device is sleeved on the outside of the electric motor shaft and connected to the electric motor housing; the conductive device is used to electrically connect the electric motor shaft and the electric motor housing, so that the electric motor shaft is grounded through the electric motor housing.

[0015] In one possible implementation, the motor further includes: a bearing and a bearing cover; the bearing is sleeved on the outside of the motor shaft and located between the motor shaft and the motor housing; the bearing cover is connected to the motor housing; and the conductive ring of the conductive device is connected to the bearing cover; the bearing cover is used to fix the bearing and connect the conductive ring to the motor housing.

[0016] According to the above technical solution, the conductive device includes a conductive ring and a carbon fiber conductive brush. The conductive ring is connected to the motor housing, the first end of the carbon fiber conductive brush is connected to the conductive ring, and the second end of the carbon fiber conductive brush is interference-fitted with the motor shaft. This allows the motor shaft to be electrically connected to the motor housing through the carbon fiber conductive brush and the conductive ring, achieving grounding through the motor housing. This allows the current generated by the motor shaft during motor operation to be discharged, preventing damage to the motor structure due to current. Compared with existing technologies, because the conductive device uses a long-life carbon fiber conductive brush, no maintenance is required during the motor's lifespan. Furthermore, because the carbon fiber conductive brush is made of carbon fiber, it does not generate powder that contaminates the grease in the motor bearings during operation, increasing bearing life and improving motor reliability. Additionally, because the conductive device adopts an arc-shaped sheet structure, there is no need to disassemble the motor shaft and bearings when replacing the conductive device, resulting in lower maintenance costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a conductive device provided in an embodiment of this application;

[0018] Figure 2 This is an exploded view of a conductive ring provided in an embodiment of this application;

[0019] Figure 3 This is a schematic diagram of a lower fan ring provided in an embodiment of this application;

[0020] Figure 4 This is an exploded view of a motor component structure provided in an embodiment of this application.

[0021] List of reference numerals in the attached diagram:

[0022] 10: Conductive device; 11: Conductive ring; 12: Carbon fiber conductive brush

[0023] 13: Recessed stop; 111: Upper fan ring; 112: Metal plate

[0024] 113: Lower fan ring; 114: Rivet; 1131: Protruding structure

[0025] 1132: Blocking structure; 121: Carbon fiber brush; 20: Motor

[0026] 21: Motor housing; 22: Motor shaft; 23: Bearing cover

[0027] 24: Bearings Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0029] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0030] As mentioned earlier, when using a variable-frequency drive (VFD) to drive an AC motor, the sum of the three-phase output voltages of the VFD is not always zero. This non-zero sum is the common-mode voltage. Due to the presence of this high-frequency common-mode voltage and stray capacitance in the circuit, electrical discharge current, high-frequency circulating current, and shaft-to-ground current are generated on the motor shaft. This can cause bearing discharge, leading to bearing seizure due to high temperature and unexpected motor shutdown. Currently, grounding carbon brushes are installed on the motor shaft to conduct the current generated on the shaft to the ground. However, current grounding carbon brushes have a short lifespan, requiring frequent replacement, resulting in high maintenance costs. Furthermore, worn carbon brushes produce powder that contaminates the grease in the motor bearings, reducing bearing life and leading to lower motor reliability.

[0031] This application provides a conductive device and a motor. The conductive device includes a conductive ring and a carbon fiber conductive brush. The conductive ring is connected to the motor housing, and the first end of the carbon fiber conductive brush is connected to the conductive ring. The second end of the carbon fiber conductive brush is interference-fitted with the motor shaft, allowing the motor shaft to be electrically connected to the motor housing through the carbon fiber conductive brush and the conductive ring. This enables grounding through the motor housing and allows the current generated by the motor shaft during motor operation to be discharged, preventing damage to the motor structure due to current. Compared with the prior art, the conductive device uses a long-life carbon fiber conductive brush, requiring no maintenance during the motor's lifespan. Furthermore, because the carbon fiber conductive brush is made of carbon fiber, it does not generate powder that contaminates the grease in the motor bearings during operation, increasing bearing life and improving motor reliability. Additionally, because the conductive device adopts an arc-shaped sheet structure, replacing the conductive device does not require disassembling the motor shaft and bearings, resulting in lower maintenance costs.

[0032] It should be noted that the accompanying drawings in this application are only for the purpose of illustrative purposes and understanding of this embodiment, and are not intended to limit this application in any way. They are not necessarily drawn to scale.

[0033] The conductive device and motor provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0034] Figure 1 This is a schematic diagram of a conductive device provided in an embodiment of this application. The conductive device 10 is disposed in a motor, enabling the motor shaft to be grounded, such as... Figure 1 As shown, the conductive device 10 includes a conductive ring 11 and a carbon fiber conductive brush 12.

[0035] The conductive ring 11 has an arc-shaped sheet structure and can be connected to the motor housing. After the conductive ring 11 is connected to the motor housing, it is fitted onto the outside of the motor shaft.

[0036] The inner arc dimension of the conductive ring 11 is smaller than the outer arc dimension. The first end of the carbon fiber conductive brush 12 is connected to the inner surface of the conductive ring 11, which is the inner arc surface of the conductive ring 11. The second end of the carbon fiber conductive brush 12 extends in the direction of the motor shaft. Optionally, the carbon fiber conductive brush 12 can extend along the radius of the inner arc of the conductive ring 11. The carbon fiber conductive brush 12 is in contact with the motor shaft, for example, the carbon fiber conductive brush 12 is interference-fitted with the motor shaft. The carbon fiber conductive brush 12 is conductive. Since the first end of the carbon fiber conductive brush 12 is connected to the conductive ring 11 and the second end is in contact with the motor shaft, the motor shaft and the conductive ring 11 can be electrically connected through the carbon fiber conductive brush 12, forming a low-resistance conductive path between the conductive device 10 and the motor shaft. Furthermore, since the conductive ring 11 is electrically connected to the motor housing, the motor shaft is grounded through the conductive device 10 and the motor housing, thus conducting the current generated by the motor shaft to the ground.

[0037] Optionally, both the inner and outer arcs of the conductive ring 11 are semicircular. When both the inner and outer arcs of the conductive ring 11 are semicircular, the coverage of the conductive ring 11 can be increased, and the conductive ring 11 will not be blocked by the motor shaft when disassembling the conductive device 10. The process of replacing the conductive device 10 is more convenient and the maintenance cost is lower.

[0038] In this embodiment, the conductive device 10 includes a conductive ring 11 and a carbon fiber conductive brush 12. The conductive ring 11 is connected to the motor housing, and the first end of the carbon fiber conductive brush 12 is connected to the conductive ring 11. The second end of the carbon fiber conductive brush 12 is interference-fitted with the motor shaft, allowing the motor shaft to be electrically connected to the motor housing through the carbon fiber conductive brush 12 and the conductive ring 11. This enables grounding through the motor housing and allows the current generated by the motor shaft during motor operation to be discharged, preventing damage to the motor structure due to current. Compared with the prior art, the conductive device 10 uses a conductive brush made of long-life carbon fiber material, requiring no maintenance during the motor's lifespan. Furthermore, because the carbon fiber conductive brush 12 is made of carbon fiber, it does not generate powder that contaminates the grease in the motor bearings during operation, increasing bearing life and improving motor reliability. Additionally, because the conductive device 10 adopts an arc-shaped sheet structure, replacing the conductive device 10 does not require disassembling the motor shaft and bearings, resulting in lower maintenance costs.

[0039] In one possible implementation, such as Figure 1 As shown, the carbon fiber conductive brush 12 includes multiple sets of carbon fiber brushes 121.

[0040] Each set of carbon fiber brushes 121 includes one or more carbon fibers, and the first end of the carbon fiber brush 121 is connected to the inner surface of the conductive ring 11. Multiple sets of carbon fiber brushes 121 are periodically distributed on the inner surface of the conductive ring 11, that is, the distance between two adjacent sets of carbon fiber brushes 121 is a fixed value, and the second end of each set of carbon fiber brushes 121 is in contact with the motor shaft.

[0041] In this embodiment, the carbon fiber conductive brush 12 includes multiple sets of carbon fiber brushes 121. The multiple sets of carbon fiber brushes 121 can increase the electrical connection area between the conductive ring 11 and the motor shaft, thereby increasing the electrical connection stability between the conductive ring 11 and the motor shaft, so that the motor shaft can be stably grounded.

[0042] Figure 2 This is an exploded view of a conductive ring provided in an embodiment of this application. Figure 2 As shown, the conductive ring 11 includes an upper fan ring 111, a lower fan ring 113, and a metal plate 112.

[0043] The upper fan ring 111, lower fan ring 113, and metal plate 112 are all arc-shaped sheet structures. The upper fan ring 111 is mounted on the lower fan ring 113, and the metal plate 112 is located between the upper fan ring 111 and the lower fan ring 113. The inner arc radius of the upper fan ring 111 is equal to the inner arc radius of the lower fan ring 113, and the outer arc radius of the upper fan ring 111 is smaller than the outer arc radius of the lower fan ring 113. During installation, the inner arc of the upper fan ring 111 is aligned with the inner arc of the lower fan ring 113.

[0044] Optionally, the arc length of the inner arc of the upper fan ring 111 is equal to the arc length of the inner arc of the lower fan ring 113.

[0045] Optionally, the metal plate 112 may have the same shape as the upper fan ring 111, that is, the inner arc radius of the metal plate 112 is the same as the inner arc radius of the upper fan ring 111, and the arc length of the inner arc of the metal plate 112 is the same as the arc length of the inner arc of the upper fan ring 111, the outer arc radius of the metal plate 112 is the same as the outer arc radius of the upper fan ring 111, and the arc length of the outer arc of the metal plate 112 is the same as the arc length of the outer arc of the upper fan ring 111.

[0046] Both the upper fan ring 111 and the lower fan ring 113 include multiple connecting holes. The connecting holes of the upper fan ring 111 are opposite to those of the lower fan ring 113. The upper fan ring 111 and the lower fan ring 113 can be connected by rivets 114 passing through the connecting holes. It should be understood that the metal plate 112 is located between the upper fan ring 111 and the lower fan ring 113. The metal plate 112 also has connecting holes at the corresponding positions of the connecting holes of the upper fan ring 111 and the lower fan ring 113. When the rivets 114 connect the upper fan ring 111 and the lower fan ring 113, the metal plate 112 will be fixedly connected between the upper fan ring 111 and the lower fan ring 113.

[0047] The inner arc surface of the metal plate 112 opposite to the motor shaft is provided with multiple blind holes. The first end of each group of carbon fiber brushes 121 in the carbon fiber conductive brush 12 is inserted into the blind hole of the metal plate 112, and the second end of each group of carbon fiber brushes 121 in the carbon fiber conductive brush 12 extends in the direction of the motor shaft and contacts the motor shaft to achieve electrical connection with the motor shaft.

[0048] In this embodiment, the conductive ring 11 includes an upper fan ring 111, a lower fan ring 113, and a metal plate 112. The upper fan ring 111 is connected to the lower fan ring 113, and the metal plate 112 is located between the upper fan ring 111 and the lower fan ring 113. The first end of the carbon fiber conductive brush 12 is connected to the metal plate 112, and the second end of the carbon fiber conductive brush 12 is interference-fitted with the motor shaft to ground the motor shaft. Due to the modular design, the position of the metal plate 112 can be fixed by the upper fan ring 111 and the lower fan ring 113 to prevent the metal plate 112 from detaching during operation. Furthermore, if the conductive device 10 is damaged, only some components can be replaced instead of replacing the entire conductive device 10, thus reducing maintenance costs.

[0049] In one possible implementation, such as Figure 2 As shown, the lower fan ring 113 includes an arc-shaped sheet-like protrusion structure 1131.

[0050] The arc-shaped protrusion 1131 on the lower fan ring 113 has the same shape as the upper fan ring 111. The inner arc radius of the protrusion 1131 is equal to the inner arc radius of the lower fan ring 113 and the inner arc radius of the upper fan ring 111. The outer arc radius of the protrusion 1131 is equal to the outer arc radius of the upper fan ring 111. The protrusion 1131 can be formed by bending a part of the structure of the lower fan ring 113, for example, by stamping to form the lower fan ring 113 including the protrusion 1131.

[0051] The outer arc edge of the arc-shaped protrusion 1131 is provided with a blocking structure 1132. When assembled into a conductive ring 11, the protrusion 1131 is attached to the upper fan ring 111, the metal plate 112 is located between the upper fan ring 111 and the protrusion 1131, and the blocking structure 1132 contacts the outer arc surface of the upper fan ring 111, which plays a limiting role.

[0052] In this embodiment, the lower fan ring 113 includes an arc-shaped protrusion 1131, which has the same shape as the upper fan ring 111. The lower fan ring 113 is connected to the upper fan ring 111 through the protrusion 1131. The metal plate 112 is located between the protrusion 1131 and the upper fan ring 111. A blocking structure 1132 is provided on the outer arc edge of the protrusion 1131. The installation of the upper fan ring 111 can be limited by the blocking structure 1132 and the protrusion 1131, so as to ensure the accurate installation position of each component of the conductive device 10.

[0053] In one possible implementation, the lower fan ring 113 can be connected to the bearing cover in the motor.

[0054] The bearing cover secures the bearing, which is fitted onto the outside of the motor shaft. The bearing cover is located between the bearing and the conductive ring 11. It should be understood that a motor typically includes two bearings and four bearing covers. Two bearing covers and one bearing form a group, with two groups located at opposite ends of the motor shaft. Both groups have identical structures: one bearing cover is located outside the motor housing, and the other is located inside the motor housing, fixing the bearing between the motor housing and the motor shaft. The lower fan ring 113 can be connected to the bearing cover located inside the motor housing. Optionally, the lower fan ring 113 can be connected to the bearing cover in the motor using bolts. Optionally, the fit tolerance between the lower fan ring 113 and the bearing cover in the motor is H8 / h7, which ensures error-proofing during assembly and guarantees coaxiality.

[0055] Optionally, the lower fan ring 113 and the bearing cover can be limited by a stop. Figure 3 This is a schematic diagram of a lower fan ring provided in an embodiment of this application. Figure 2 and Figure 3As shown, a recessed stop 13 can be provided on the lower fan ring 113, and correspondingly, a raised stop can be provided at the mounting position of the bearing cover of the motor. Optionally, the fit tolerance of the stop limit between the lower fan ring 113 and the bearing cover can be set according to H7 / h6.

[0056] In this embodiment, the lower fan ring 113 is connected to the bearing cover in the motor, and the conductive ring 11 can be connected to the motor housing through the bearing cover in the motor, so that the motor shaft can be connected to the motor housing through the conductive device 10, thereby grounding through the motor housing. The current generated by the motor shaft can be conducted to the ground through the motor housing, preventing the bearing from being damaged by the current. Furthermore, the lower fan ring 113 and the bearing cover can be limited by a stop, which can ensure the accuracy of the installation.

[0057] In one possible implementation, the eccentricity between the multiple sets of carbon fiber brushes 121 and the motor shaft is less than 0.15 mm.

[0058] In this embodiment, the eccentricity between the multiple sets of carbon fiber brushes 121 and the motor shaft is less than 0.15mm, which prevents the carbon fiber conductive brushes 12 from being worn unevenly by the motor shaft due to eccentricity after long-term use, thereby improving the service life of the carbon fiber conductive brushes 12 and thus improving the reliability of the conductive device 10.

[0059] In one possible implementation, the distance between the tip of the second end of the carbon fiber conductive brush 12 and the axis of the motor shaft is D1 = D / 2 - δ, where D1 represents the distance between the tip of the second end of the carbon fiber conductive brush 12 and the axis of the motor shaft, D represents the diameter of the motor shaft in the area where the conductive ring 11 is sleeved, and δ = 2 * n * π * D * 10 -6 , where n is used to characterize the speed of the motor.

[0060] Optionally, the inner arc diameter of the metal plate 112, the inner arc diameter of the upper fan ring 111, and the inner arc diameter of the lower fan ring 113 in the conductive ring 11 can be D2 = D + 5; the inner diameter of the stop between the conductive ring 11 and the bearing cover of the motor can be D3 = D + 9; the outer arc diameter of the protrusion structure 1131 of the lower fan ring 113, the outer arc diameter of the upper fan ring 111, and the outer arc diameter of the metal plate 112 can be D4 = D3 + 5; and the outer arc diameter of the lower fan ring 113 can be D5 = D3 + 20. It should be noted that the aforementioned dimensions can be measured in centimeters according to the size of the motor. For example, when the motor is large, the unit can be centimeters.

[0061] In this embodiment, by limiting the distance between the second end of the carbon fiber conductive brush 12 and the axis of the motor shaft, an interference fit can be made between the second end of the carbon fiber conductive brush 12 and the motor shaft, so that the carbon fiber conductive brush 12 can form a low-resistance conductive path with the motor shaft, thereby improving the stability of the electrical connection between the carbon fiber conductive brush 12 and the motor shaft and preventing the motor shaft from failing to ground due to the loss of electrical connection between the carbon fiber conductive brush 12 and the motor shaft, thus improving the reliability of the motor.

[0062] This application embodiment also provides an electric motor, including an electric motor housing, an electric motor shaft, and a conductive device 10 as in any of the foregoing embodiments. The conductive device 10 is sleeved on the outside of the electric motor shaft and connected to the electric motor housing. The conductive device 10 can electrically connect the electric motor shaft and the electric motor housing, so that the electric motor shaft is grounded through the electric motor housing.

[0063] In this embodiment, the motor housing can be the motor housing in any of the foregoing embodiments, the motor shaft can be the motor shaft in any of the foregoing embodiments, and the conductive device 10 can be the conductive device 10 in any of the foregoing embodiments. The specific structure and connection relationship can be referred to the description in any of the foregoing embodiments, and will not be repeated here.

[0064] Figure 4 This is an exploded view of a motor component structure provided in an embodiment of this application. Figure 4 The exploded view shown is along the axial direction of the motor shaft 22, as follows: Figure 4 As shown, the motor 20 also includes a bearing 24 and a bearing cover 23. The bearing 24 is sleeved outside the motor shaft 22 and is located between the motor shaft 22 and the motor housing 21. The bearing cover 23 is connected to the motor housing 21. The conductive ring 11 of the conductive device 10 is connected to the bearing cover 23. The bearing cover 23 can fix the bearing 24 and connect the conductive ring 11 to the motor housing 21.

[0065] Optionally, the lower fan ring 113 of the conductive ring 11 of the conductive device 10 and the bearing cover 23 are limited by a stop, for example: Figure 3 As shown, a recessed stop 13 can be provided inside the lower fan ring 113, and correspondingly, a convex stop can be provided at the mounting position of the bearing cover 23 of the motor 20.

[0066] Optionally, the motor 20 may include two bearings 24 and four bearing covers 23. The two bearing covers 23 and one bearing 24 form a group, with two groups respectively located at both ends of the motor shaft 22. Both groups have identical structures: one bearing cover 23 is located outside the motor housing 21 of the motor 20, and the other bearing cover 23 is located inside the motor housing 21, fixing the bearing 24 between the motor housing 21 and the motor shaft 22. Correspondingly, the motor 20 includes two conductive devices 10. The lower fan ring 113 of the conductive device 10 can be connected to the bearing cover 23 located inside the motor housing 21. Different lower fan rings 113 in different conductive devices 10 are connected to different bearing covers 23 located inside the motor housing 21.

[0067] Alternatively, the lower fan ring 113 can be connected to the bearing cover 23 in the motor 20 by bolts.

[0068] It should be noted that, Figure 4 The diagram only shows a portion of the motor 20 structure relevant to the embodiments of this application and should not impose any limitations on the overall structure of the motor 20.

[0069] In this embodiment, the motor 20 further includes a bearing 24 and a bearing cover 23. The bearing 24 is located between the motor shaft 22 and the motor housing 21, and can limit the movement of the motor shaft 22 and allow it to rotate relative to the motor housing 21. The bearing cover 23 can mount the bearing 24 onto the motor housing 21. The conductive device 10 can be connected to the bearing cover 23, thereby allowing the motor shaft 22 to be electrically connected to the motor housing 21 through the carbon fiber conductive brush 12 and conductive ring 11 of the conductive device 10. This enables grounding through the motor housing 21 and allows the current generated by the motor shaft 22 during motor operation to be discharged, preventing damage to the motor 20 structure due to current. Compared with the prior art, since the conductive device 10 uses a long-life carbon fiber conductive brush 12, no maintenance is required during the lifespan of the motor 20. Furthermore, since the carbon fiber conductive brush 12 is made of carbon fiber material, it will not generate powder that contaminates the grease in the bearing 24 during motor operation, thus increasing the service life of the bearing 24 and improving the reliability of the motor 20. Furthermore, since the conductive device 10 adopts an arc-shaped sheet structure, it is not necessary to disassemble the motor shaft 22 and the bearing 24 in the motor 20 when replacing the conductive device 10, resulting in lower maintenance costs.

[0070] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0071] In this patent application, nouns and pronouns relating to people are not limited to specific genders.

[0072] Finally, it should be noted that the above are merely preferred embodiments of this utility model, used only to illustrate the technical solution of this utility model, and are not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model are included within the scope of protection of this utility model.

Claims

1. An electrically conductive device (10) for grounding a motor shaft (22) of an electric motor (20), characterized in that, The conductive device (10) includes: a conductive ring (11) and a carbon fiber conductive brush (12); The conductive ring (11) is an arc-shaped sheet structure. The conductive ring (11) is connected to the motor housing (21) of the motor (20). The conductive ring (11) is sleeved on the outside of the motor shaft (22). The first end of the carbon fiber conductive brush (12) is connected to the inner surface of the conductive ring (11). The second end of the carbon fiber conductive brush (12) extends in the direction of the motor shaft (22) and contacts the motor shaft (22). The carbon fiber conductive brush (12) is used to electrically connect the motor shaft (22) to the conductive ring (11), so that the motor shaft (22) is grounded through the motor housing (21).

2. The conductive device (10) according to claim 1, characterized in that, The carbon fiber conductive brush (12) includes: multiple sets of carbon fiber brushes (121), each set of carbon fiber brushes (121) includes one or more carbon fibers, the first end of each set of carbon fiber brushes (121) is connected to the inner surface of the conductive ring (11), and the multiple sets of carbon fiber brushes (121) are periodically distributed on the inner surface of the conductive ring (11), and the second end of each set of carbon fiber brushes (121) is in contact with the motor shaft (22).

3. The electrically conductive device (10) according to claim 1, characterized in that The conductive ring (11) includes: an upper fan ring (111), a lower fan ring (113), and a metal plate (112); The upper fan ring (111), the lower fan ring (113), and the metal plate (112) are all arc-shaped sheet structures. The inner arc radius of the upper fan ring (111) is equal to that of the lower fan ring (113), and the outer arc radius of the upper fan ring (111) is smaller than that of the lower fan ring (113). The metal plate (112) is disposed between the upper fan ring (111) and the lower fan ring (113). The upper fan ring (111), the metal plate (112), and the lower fan ring (113) are connected by rivets (114). The first end of the carbon fiber conductive brush (12) is inserted into the blind hole of the metal plate (112).

4. The electrically conductive device (10) according to claim 3, characterized in that The lower fan ring (113) includes an arc-shaped sheet-like protrusion structure (1131), the inner arc radius of the protrusion structure (1131) is equal to the inner arc radius of the upper fan ring (111), the outer arc radius of the protrusion structure (1131) is equal to the outer arc radius of the upper fan ring (111), and a blocking structure (1132) is provided on the outer arc edge of the protrusion structure (1131). The protruding structure (1131) is configured to be connected to the upper fan ring (111), and the metal plate (112) is located between the upper fan ring (111) and the protruding structure (1131); The blocking structure (1132) is configured to contact the outer arc surface of the upper fan ring (111).

5. The electrically conductive device (10) according to claim 3, characterized in that The lower fan ring (113) is connected to the bearing cover (23) in the motor (20), wherein the bearing cover (23) is used to fix the bearing (24), the bearing (24) is sleeved on the outside of the motor shaft (22), and the bearing cover (23) is located between the bearing (24) and the conductive ring (11).

6. The electrically conductive device (10) according to claim 5, characterized in that The lower fan ring (113) and the bearing cover (23) are limited by a stop.

7. The electrically conductive device (10) according to claim 2, characterized in that The eccentricity between the multiple sets of carbon fiber brushes (121) and the motor shaft (22) is less than 0.15 mm.

8. The conductive device (10) according to claim 1, characterized in that The distance between the second end of the carbon fiber conductive brush (12) and the axis of the motor shaft (22) is D1 = D / 2 - δ, where D1 represents the distance between the second end of the carbon fiber conductive brush (12) and the axis of the motor shaft (22), D represents the diameter of the motor shaft (22) in the area where the conductive ring (11) is sleeved, and δ = 2 * n * π * D * 10 -6 n is used to characterize the rotational speed of the motor (20).

9. An electric motor (20), characterized in that, include: The motor housing (21), the motor shaft (22), and the conductive device (10) as described in any one of claims 1-8; The conductive device (10) is sleeved on the outside of the motor shaft (22), and the conductive device (10) is connected to the motor housing (21); The conductive device (10) is used to electrically connect the motor shaft (22) and the motor housing (21) so that the motor shaft (22) is grounded through the motor housing (21).

10. The electric machine (20) of claim 9, characterized in that The motor (20) also includes: a bearing (24) and a bearing cover (23); The bearing (24) is sleeved on the outside of the motor shaft (22) and located between the motor shaft (22) and the motor housing (21). The bearing cover (23) is connected to the motor housing (21). The conductive ring (11) of the conductive device (10) is connected to the bearing cover (23). The bearing cover (23) is used to fix the bearing (24) and connect the conductive ring (11) to the motor housing (21).

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