An electric machine, grounding device and traction system

Abstract

The application discloses a motor, a grounding device and a traction system. The motor comprises a motor shell, a motor shaft, a bearing, a grounding device, wherein the motor shaft is rotatably arranged in the motor shell through the bearing; the grounding device comprises a conductive sleeve, a positioning component and a carbon brush assembly; the conductive sleeve is used for connecting with the motor shell and has a channel for the carbon brush assembly to move; the positioning component is detachably arranged at one end of the channel, and the other end of the channel can be directed to the motor shaft; the carbon brush assembly comprises a carbon brush component movably arranged in the channel and an elastic component arranged between the positioning component and the carbon brush component, and the elastic component can exert an elastic force on the carbon brush component towards the motor shaft. The motor provided by the application can prevent the bearing from being electrically corroded and avoid the bearing failure.

Description

Technical Field

[0001] This invention relates to the field of electrical equipment technology, and in particular to an electric motor, a grounding device, and a traction system. Background Technology

[0002] A typical three-phase AC power supply is balanced and symmetrical under normal conditions, meaning the vector sum of the three phases is zero. The traction motor shaft voltage originates from the inverter's PWM (Pulse Width Modulation) control. The PWM inverter converts the DC bus voltage into AC PWM pulse voltage, which is then output to the traction motor to drive it. Although the U, V, and W phases at the output have a 120° phase difference, their sum is not zero, indicating a high common-mode voltage. When this high-frequency common-mode voltage acts on the motor, due to the parasitic capacitance within the motor, a shaft voltage (the voltage between the motor shaft and the motor housing) is coupled onto the bearing. This shaft voltage directly affects the bearing, easily causing electrolytic corrosion and leading to bearing failure.

[0003] Therefore, how to prevent bearing electro-corrosion and avoid bearing failure is a problem that urgently needs to be solved by those in this technical field. Summary of the Invention

[0004] In view of this, the present invention provides an electric motor to prevent bearing electro-corrosion and avoid bearing failure. The present invention also provides a traction system and a grounding device.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An electric motor, comprising:

[0007] Motor housing;

[0008] Motor shaft;

[0009] The motor shaft is rotatably mounted within the motor housing via the bearing.

[0010] A grounding device, the grounding device comprising a conductive jacket, a positioning component, and a carbon brush assembly;

[0011] in,

[0012] The conductive jacket is used to connect to the motor housing and has a channel for the carbon brush assembly to move. The positioning component is detachably disposed at one end of the channel, and the other end of the channel can face the motor shaft.

[0013] The carbon brush assembly includes a carbon brush component movably disposed within the channel and an elastic component disposed between the positioning component and the carbon brush component, the elastic component being capable of applying an elastic force toward the motor shaft to the carbon brush component.

[0014] Optionally, in the above-mentioned motor, the channel includes a threaded section near one end thereto, and the positioning component has a first external thread structure;

[0015] When the positioning component is located at one end of the channel, the first external thread structure engages with the threaded segment so that the positioning component is at least partially embedded in the channel.

[0016] Optionally, in the above-mentioned motor, the positioning component has a first end and a second end facing away from each other;

[0017] The first end has a connecting portion that mates with a tightening tool; and / or the second end has a limiting portion that mates with the carbon brush assembly.

[0018] Optionally, in the above-described motor, the carbon brush assembly further includes:

[0019] A brush petal, one end of which is connected to the carbon brush component, and an elastic component is sleeved on the outside of the brush petal;

[0020] A washer that is movable along the extension direction of the brush petal, the washer having a first side and a second side facing away from each other, the first side contacting the positioning member, and the second side contacting the end of the elastic member facing away from the carbon brush member;

[0021] A limiting component is provided, which is connected to the other end of the brush petal and makes limiting contact with the washer.

[0022] Optionally, in the above-mentioned motor, the channel includes a limiting section, and the carbon brush component cooperates with the limiting section to restrict the circumferential rotation of the carbon brush component.

[0023] Optionally, in the above-mentioned motor, the channel further includes a sliding section, which is located on the side of the limiting section opposite to the other end of the channel, and the carbon brush component is clearance-fitted with the sliding section.

[0024] Optionally, in the above-mentioned motor, the cross-section of the carbon brush component is a first non-circular cross-section, and the cross-section of the limiting section is a second non-circular cross-section that mates with the first non-circular cross-section.

[0025] Optionally, in the above-mentioned motor, the conductive jacket is mounted on the motor cover plate of the motor housing.

[0026] Optionally, in the above-mentioned motor, the conductive sleeve has a second external thread structure, and the motor housing has a threaded hole that mates with the second external thread structure.

[0027] The present invention also provides a grounding device, which includes a conductive jacket, a positioning component, and a carbon brush assembly;

[0028] in,

[0029] The conductive jacket is used to connect to the motor housing and has a channel for the carbon brush assembly to move. The positioning component is detachably disposed at one end of the channel, and the other end of the channel can face the motor shaft.

[0030] The carbon brush assembly includes a carbon brush component movably disposed within the channel and an elastic component disposed between the positioning component and the carbon brush component, the elastic component being capable of applying an elastic force toward the motor shaft to the carbon brush component.

[0031] The present invention also provides a traction system including a traction motor, wherein the traction motor is a motor as described in any of the preceding claims.

[0032] As can be seen from the above technical solution, the motor provided by this invention has a grounding device between the motor housing and the motor shaft. The conductive sleeve of the grounding device is connected to the motor housing. Because the positioning component and one end of the elastic component abut against each other, the carbon brush component of the carbon brush assembly can be movably disposed within the channel of the conductive sleeve. Under the elastic force of the elastic component, it can contact the motor shaft, thereby forming a grounding path between the motor housing, the conductive sleeve, the carbon brush component, and the motor shaft. This design effectively reduces the motor shaft voltage, protects the bearings in the motor, prevents bearing electro-corrosion, effectively avoids bearing failure due to electro-corrosion, extends the service life of the bearings, and also extends the service life of the motor.

[0033] The present invention also provides a grounding device. Since the above-mentioned motor has the above-mentioned technical effects, the above-mentioned grounding device should also have the same technical effects, and will not be described in detail here.

[0034] The present invention also provides a traction system, including a traction motor, which is any of the motors described above. Since the motors described above have the aforementioned technical effects, the traction system using the aforementioned motor as the traction motor should also have the same technical effects, and will not be described in detail here. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the structure of the motor shaft inside the motor provided in an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of the structure of the fan cover provided in an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the structure of the motor housing provided in an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of the assembly structure of the grounding device and the motor housing provided in an embodiment of the present invention;

[0040] Figure 5 A cross-sectional view of the motor provided in an embodiment of the present invention;

[0041] Figure 6 This is a schematic diagram of the grounding device provided in an embodiment of the present invention;

[0042] Figure 7 A schematic diagram of the structure of the conductive jacket provided in an embodiment of the present invention;

[0043] Figure 8 For along Figure 7 Schematic diagram of the cross-sectional structure of the AA surface in the middle;

[0044] Figure 9 This is a schematic diagram of the positioning component provided in an embodiment of the present invention;

[0045] Figure 10 For along Figure 9 Schematic diagram of the cross-sectional structure of the BB surface in the middle;

[0046] Figure 11 This is a schematic diagram of the carbon brush assembly provided in an embodiment of the present invention.

[0047] in,

[0048] Motor shaft-100, motor housing-200, housing body-210, motor cover-220, fan-300, grounding device-400, conductive jacket-1, channel-11, countersunk hole-110, threaded section-111, sliding section-112, limiting section-113, bolt head-12, second external thread structure-13, positioning component-2, first external thread structure-20, connecting part-21, limiting part-22, carbon brush assembly-3, carbon brush component-31, elastic component-32, brush petal-33, washer-34, limiting component-35. Detailed Implementation

[0049] This invention discloses an electric motor to prevent bearing electro-corrosion and avoid bearing failure. This invention also provides a traction system and a grounding device.

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] like Figures 1-11 As shown, this embodiment of the invention provides an electric motor, including a motor housing 200, a motor shaft 100, bearings, and a grounding device 400. The motor shaft 100 is rotatably mounted within the motor housing 200 via bearings. The grounding device 400 includes a conductive sleeve 1, a positioning component 2, and a carbon brush assembly 3. The conductive sleeve 1 is connected to the motor housing 200 and has a channel 11 for the carbon brush assembly 3 to move. The positioning component 2 is detachably mounted at one end of the channel 11, and the other end of the channel 11 can face the motor shaft 100. The carbon brush assembly 3 includes a carbon brush component 31 movably mounted within the channel 11 and an elastic component 32 disposed between the positioning component 2 and the carbon brush component 31. The elastic component 32 can apply an elastic force to the carbon brush component 31 toward the motor shaft 100.

[0052] The motor provided in this embodiment of the invention has a grounding device 400 installed between the motor housing 200 and the motor shaft 100. The conductive outer sleeve 1 of the grounding device 400 is connected to the motor housing 200. Since the positioning component 2 and one end of the elastic component 32 abut against each other, the carbon brush component 31 of the carbon brush assembly 3 can be movably disposed within the channel 11 of the conductive outer sleeve 1. Under the elastic force of the elastic component 32, it can contact the motor shaft 100, thereby forming a grounding path between the motor housing 200, the conductive outer sleeve 1, the carbon brush component 31, and the motor shaft 100. Through this arrangement, the voltage on the motor shaft 100 is effectively reduced, protecting the bearings in the motor, preventing bearing electro-corrosion, effectively avoiding bearing failure due to electro-corrosion, extending the service life of the bearings, and also extending the service life of the motor.

[0053] Taking a traction motor installed in a subway vehicle traction system as an example, by setting the aforementioned grounding device 400 between the motor housing 200 and the motor shaft 100, the carbon brush assembly 3 can be installed on the non-driving end of the traction motor. According to the inventor's tests, the peak shaft voltage can be reduced to 30V-40V.

[0054] A fan 300 may be installed on the motor shaft 100, which drives the fan 300 to rotate during the rotation of the motor shaft 100. The motor housing 200 may include a housing body 210 and a motor cover plate 220 connected to the housing body 210. The motor cover plate 220 may be used as a fan cover plate, and a grounding device 400 may be installed on the motor cover plate 220.

[0055] After the grounding device 400 is installed, under the elastic force of the elastic member 32, the carbon brush member 31 will be pushed against the motor shaft (motor shaft 100), so that the motor shaft 100 contacts the carbon brush member 31, the carbon brush member 31 is connected to the motor housing 200, and the motor shaft 100 is connected to the motor housing 200, thereby reducing the voltage of the motor shaft 100.

[0056] During installation, first install the conductive jacket 1 onto the motor housing 200, then place the carbon brush assembly 3 into the conductive jacket 1, and finally install the positioning component 2.

[0057] The conductive jacket 1 can be a jacket structure made of brass, iron or other conductive metals.

[0058] To facilitate the detachable installation of the positioning component 2 at one end of the channel 11, the channel 11 includes a threaded section 111 near one end, and the positioning component 2 has a first external thread structure 20. When the positioning component 2 is installed at one end of the channel 11, the first external thread structure 20 is threadedly engaged with the threaded section 111, so that the positioning component 2 is at least partially embedded in the channel 11. When it is necessary to replace the carbon brush assembly 31, the first external thread structure 20 can be separated from the threaded section 111 by turning the positioning component 2, thereby removing the positioning component 2 from one end of the channel 11. That is, when replacing the carbon brush assembly 31, only the positioning component 2 needs to be removed to take out and replace the carbon brush assembly 31, making replacement extremely convenient.

[0059] The positioning component 2 can be fully embedded in the channel 11, or it can be partially embedded in the channel 11.

[0060] It is also possible to make the threaded section 111 of the channel 11 facing away from the carbon brush component 31 have a countersunk hole 110 for the other parts of the positioning component 2 to be inserted.

[0061] The positioning component 2 may have a first end and a second end facing away from each other; wherein the first end has a connecting part 21 that cooperates with a tightening tool; and / or, the second end has a limiting part 22 that cooperates with the carbon brush assembly 3 for limiting.

[0062] like Figure 6 As shown, in some embodiments, the positioning component 2 can be a flat-ended set screw, so that the positioning component 2 is fully embedded in the channel 11. The connecting part 21 of the positioning component 2 can be a recessed hole, which can be a prism hole (such as a hexagonal prism) to facilitate rotation with a corresponding tightening tool.

[0063] The limiting part 22 at the second end can be a plane, which abuts against the end of the elastic part 32 of the carbon brush assembly 3 that faces away from the carbon brush assembly 31.

[0064] like Figure 10 As shown, in some embodiments, the positioning member 2 can be a bolt with a head, and the connecting portion 21 of the positioning member 2 can be the head of the positioning member 2, located outside the channel 11. That is, the bolt shank is embedded in the channel 11. In other words, the positioning member 2 is partially embedded in the channel 11. A tightening tool can engage with the head of the positioning member 2 from outside the channel 11 to tighten the positioning member 2.

[0065] The limiting part 22 at the second end can be a groove to accommodate other parts of the carbon brush assembly 3 (such as the end of the brush petal 33 facing away from the carbon brush component 31).

[0066] In some embodiments, the carbon brush assembly 3 further includes a brush petal 33, a washer 34, and a limiting member 35. One end of the brush petal 33 is connected to the carbon brush component 31, and an elastic member 32 is sleeved on the outside of the brush petal 33. The washer 34 is movable along the extending direction of the brush petal 33 and has a first surface and a second surface facing away from each other. The first surface contacts the positioning member 2, and the second surface contacts the end of the elastic member 32 facing away from the carbon brush component 31. The limiting member 35 is connected to the other end of the brush petal 33 and makes limiting contact with the washer 34. The other end of the brush petal 33 (the end facing away from the carbon brush component 31) and the limiting member 35 can be embedded in the limiting portion 22 (groove).

[0067] The elastic component 32 can be a spring or other elastic structure, such as an elastic block or a spring sheet.

[0068] In some embodiments, the channel 11 further includes a sliding section 112, which is located on the side of the limiting section 113 opposite to the other end of the channel 11. The carbon brush component 31 is clearance-fitted with the sliding section 112. By clearance-fitting the carbon brush component 31 with the sliding section 112, the friction between the carbon brush component 31 and the channel 11 is reduced, thereby facilitating the movement of the carbon brush component 31 along the channel 11.

[0069] The carbon brush component 31 has a first non-circular cross-section, and the limiting section 113 has a second non-circular cross-section that mates with the first non-circular cross-section. That is, to prevent the carbon brush component 31 from rotating, the channel 11 includes the limiting section 113, and the carbon brush component 31 mates with the limiting section 113 to restrict the circumferential rotation of the carbon brush component 31. Figure 7 As shown, the cross section (second non-circular cross section) of the limiting segment 113 can be non-circular (square, elliptical, triangular or other shapes).

[0070] The conductive sleeve 1 of the motor provided in this embodiment of the invention is mounted on the motor cover plate 220 of the motor housing 200. The conductive sleeve 1 can also be mounted on other parts of the motor housing 200; no specific limitations are imposed here.

[0071] To facilitate the installation of the conductive sleeve 1, the conductive sleeve 1 has a second external thread structure 13, and the motor housing 200 has a threaded hole that mates with the second external thread structure 13. That is, the conductive sleeve 1 can be a bolt-like structure, which can have a bolt head 12 exposed on the outside of the motor housing 200, so that the conductive sleeve 1 can be installed and removed by twisting the bolt head 12 with a screwing tool.

[0072] This invention also provides a traction system, including a traction motor, which is any of the motors described above. Since the motors described above have the aforementioned technical effects, the traction system using these motors as traction motors should also have the same technical effects, and will not be described in detail here.

[0073] This solution is mainly used in the traction system of subway vehicles. It is installed on the non-drive end of the traction system to reduce the axle voltage of the traction system.

[0074] The present invention also provides a grounding device 400, wherein the grounding device 400 includes a conductive jacket 1, a positioning component 2, and a carbon brush assembly 3. The conductive jacket 1 is used to connect to a motor housing 200 and has a channel 11 for the carbon brush assembly 3 to move. The positioning component 2 is detachably disposed at one end of the channel 11, and the other end of the channel 11 can face the motor shaft 100. The carbon brush assembly 3 includes a carbon brush component 31 movably disposed within the channel 11 and an elastic component 32 disposed between the positioning component 2 and the carbon brush component 31. The elastic component 32 can apply an elastic force toward the motor shaft 100 to the carbon brush component 31.

[0075] Since the aforementioned motor has the aforementioned technical effects, the aforementioned grounding device 400 should also have the same technical effects, and will not be described in detail here.

[0076] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0077] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electric motor, characterized in that, include: Motor housing (200); Motor shaft (100); The motor shaft (100) is rotatably mounted inside the motor housing (200) via the bearing; Grounding device (400), the grounding device (400) includes a conductive jacket (1), a positioning component (2) and a carbon brush assembly (3); in, The conductive jacket (1) is used to connect to the motor housing (200) and has a channel (11) for the carbon brush assembly (3) to move. The positioning member (2) is detachably disposed at one end of the channel (11) and the other end of the channel (11) can face the motor shaft (100). The carbon brush assembly (3) includes a carbon brush component (31) movably disposed within the channel (11) and an elastic component (32) disposed between the positioning component (2) and the carbon brush component (31), the elastic component (32) being capable of applying an elastic force toward the motor shaft (100) to the carbon brush component (31).

2. The motor as described in claim 1, characterized in that, The channel (11) includes a threaded section (111) near one end thereto, and the positioning component (2) has a first external thread structure (20). When the positioning component (2) is located at one end of the channel (11), the first external thread structure (20) is threadedly engaged with the thread segment (111) so that the positioning component (2) is at least partially embedded in the channel (11).

3. The motor as described in claim 2, characterized in that, The positioning component (2) has a first end and a second end that are opposite to each other; The first end has a connecting part (21) that cooperates with a tightening tool; and / or the second end has a limiting part (22) that cooperates with the carbon brush assembly (3).

4. The motor as described in claim 3, characterized in that, The carbon brush assembly (3) also includes: Brush petal (33), one end of which is connected to the carbon brush component (31), and the elastic component (32) is sleeved on the outside of the brush petal (33); Washer (34), which is movable along the extension direction of the brush petal (33), the washer (34) has a first side and a second side facing away from each other, the first side is in contact with the positioning member (2), and the second side is in contact with the end of the elastic member (32) facing away from the carbon brush member (31); A limiting component (35) is connected to the other end of the brush petal (33) and makes limiting contact with the washer (34).

5. The motor as described in claim 1, characterized in that, The channel (11) includes a limiting section (113), and the carbon brush component (31) cooperates with the limiting section (113) to restrict the circumferential rotation of the carbon brush component (31).

6. The motor as described in claim 5, characterized in that, The channel (11) also includes a sliding section (112), which is located on the side of the limiting section (113) facing away from the other end of the channel (11), and the carbon brush component (31) is in clearance fit with the sliding section (112).

7. The motor as described in claim 5, characterized in that, The cross-section of the carbon brush component (31) is a first non-circular cross-section, and the cross-section of the limiting segment (113) is a second non-circular cross-section that mates with the first non-circular cross-section.

8. The motor as described in any one of claims 1-7, characterized in that, The conductive jacket (1) is installed on the motor cover plate (220) of the motor housing (200).

9. A grounding device, characterized in that, The grounding device includes a conductive jacket (1), a positioning component (2), and a carbon brush assembly (3). in, The conductive jacket (1) is used to connect to the motor housing (200) and has a channel (11) for the carbon brush assembly (3) to move. The positioning member (2) is detachably disposed at one end of the channel (11) and the other end of the channel (11) can face the motor shaft (100). The carbon brush assembly (3) includes a carbon brush component (31) movably disposed within the channel (11) and an elastic component (32) disposed between the positioning component (2) and the carbon brush component (31), the elastic component (32) being capable of applying an elastic force toward the motor shaft (100) to the carbon brush component (31).

10. A traction system, comprising a traction motor, characterized in that, The traction motor is the motor as described in any one of claims 1-8.

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