A brush structure for a motor that slides in axial contact with the shaft.

Abstract

This application relates to a brush structure that slides in axial contact with a motor shaft, belonging to the field of electric motors. A brush component 3 is disposed on the end face of the first or both ends of the motor shaft 22 along its axial direction. The motor shaft 22 has a protruding structure 24 or an overall smooth recessed structure 26 along its rotation axis 25. Through the convex-concave fit between the motor shaft 22 and the contacting brush 33, the material fit strength of the brush 33 can be improved, the service life of the brush 33 can be increased, and the axial and radial runout of the motor shaft 22 can be reduced.

Description

Technical Field

[0001] This invention belongs to the field of electric motors and relates to a brush structure that slides in axial contact with a rotating shaft. Background Technology

[0002] In variable frequency, servo, or high-power motors, to eliminate the damage of shaft current to the bearings, grounding brushes are used to contact the rotating profile of the shaft, diverting the shaft current generated by the motor to the ground. To test the shaft voltage, test brushes are used to contact the rotating profile of the shaft, connecting the shaft voltage to a testing instrument. The brushes are mounted on the outer circumferential surface of the shaft; the linear velocity at the contact surface is high, resulting in severe carbon brush wear and a relatively short lifespan.

[0003] Patent CN105375228A discloses a shaft-mounted grounded carbon brush device. The brush contacts the rotation center of the shaft, reducing the linear velocity, decreasing brush wear, and effectively extending brush life. However, in a vibration environment, there is a risk that the brush may slip off the axial end face of the shaft.

[0004] US2104800A, a patent for an electrostatic eliminator, discloses a contact button in a one-piece stamped helical spring component adapted to abut against the end of a shaft or axle in its assembled position. This end has a small hole drilled therein, allowing for better contact between the contact button and the shaft. The small hole structure on the shaft can compensate for and mitigate shaft runout, achieving long-term reliable contact between the shaft and the brush. However, the shaft is a metal component, while the brush is generally a graphite-containing component. The different material strengths of these two components make the small protrusions on the brush easily damaged during shaft movement, affecting the brush's lifespan and contact performance. Summary of the Invention

[0005] The technical problem to be solved by this application is: when the brush contacts the axial concave point of the motor shaft, the material difference between the shaft and the brush makes the brush matching convex point easily damaged, and further reducing the axial and radial runout of the motor shaft.

[0006] The technical solution disclosed in this application is: Figure 1 and Figure 2The diagram illustrates a brush structure for an electric motor that slides axially with a rotating shaft. It includes a motor mounting component 1, a motor rotating component 2, and a bearing 4 that dynamically connects the mounting component 1 and the rotating component 2. The motor mounting component 1 includes a motor housing 11 and a motor stator 12. The motor rotating component 2 includes a motor rotor 21 and a motor shaft 22. It also includes a brush component 3, which comprises a brush holder 31 fixed to the end face of the first end of the motor shaft 22 on the motor housing 11. The brush holder 31 accommodates a compression spring 32 and a brush 33. The key feature is that the motor shaft 22 has a protruding structure 24 along its rotation axis 25. One end of the brush 33 is compressed by the compression spring 32, causing the other end of the brush 33 to be close to the axial end face of the motor shaft 22. The outer diameter of the brush 33 is within the range of the outer diameter of the motor shaft 22, ensuring that the unworn edge of the brush 33 does not affect the contact between the brush 33 and the rotation axis 25 of the motor shaft 22.

[0007] The beneficial technical effects of this solution are: by forming a protruding structure 24 along the rotation axis 25 of the motor shaft 22 and a concave fit with the brush 33, the material fit strength of the brush 33 can be improved, and the service life of the brush 33 can be increased. This concave-convex fit method can also reduce the axial and radial runout of the motor shaft 22. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the axial cross-section of the motor and brush structure according to an embodiment of this application.

[0009] Figure 2 This is a detailed axial cross-sectional schematic diagram of the engagement between the brush and the shaft protrusion in Embodiment 1 of this application.

[0010] Figure 3 This is a detailed axial cross-sectional schematic diagram of the brush of Embodiment 1 of this application mating with a rotating shaft with an extended outer diameter.

[0011] Figure 4 This is a detailed axial cross-sectional schematic diagram of the brush and shaft cooperation in Embodiment 2 of this application.

[0012] Figure 5 This is a detailed axial cross-sectional schematic diagram of the brush and the rotating shaft with an extended outer diameter in Embodiment 2 of this application.

[0013] Marking description: Motor fixing component 1, motor housing 11, motor stator 12, motor rotating component 2, motor rotor 21, motor shaft 22, bearing 4, brush component 3, brush holder 31, compression spring 32, brush 33, shaft expansion outer diameter component 23, protruding structure of motor shaft 24, shaft center 25, recessed structure of motor shaft 26. Detailed Implementation

[0014] Example 1: Figure 1 and Figure 2 The diagram illustrates a brush structure for an electric motor that slides axially with a rotating shaft. It includes a motor mounting component 1, a motor rotating component 2, and a bearing 4 that dynamically connects the mounting component 1 and the rotating component 2. The motor mounting component 1 includes a motor housing 11 and a motor stator 12. The motor rotating component 2 includes a motor rotor 21 and a motor shaft 22. It also includes a brush component 3, which comprises a brush holder 31 fixed to the end face of the first end of the motor shaft 22 on the motor housing 11. The brush holder 31 accommodates a compression spring 32 and a brush 33. The key feature is that the motor shaft 22 has a protruding structure 24 along its rotation axis 25. One end of the brush 33 is compressed by the compression spring 32, causing the other end of the brush 33 to be close to the axial end face of the motor shaft 22. The outer diameter of the brush 33 is within the range of the outer diameter of the motor shaft 22, ensuring that the unworn edge of the brush 33 does not affect the contact between the brush 33 and the rotation axis 25 of the motor shaft 22.

[0015] Preferably, initially, the end face of the brush 33 that contacts the motor shaft 22 along the rotation axis 25 has a recess, so that when the brush 33 is initially installed and used, the motor shaft 22 and the brush 33 have a basic positioning and cooperation.

[0016] In detail, the brush component 3 illustrated in this embodiment is a strip brush. Other existing brush forms and fixing methods, such as arc brushes and their fixing methods, are also included in the scope of protection of this application.

[0017] In detail, the protrusion structure 24 illustrated in this embodiment can be a pointed, arc-shaped or other protrusion forms suitable for the purpose of this embodiment. It can be a local protrusion within the axial range or an integral protrusion formed on the end face of the entire axial direction.

[0018] The technical effect of this embodiment is that by forming a protruding structure 24 along the rotation axis 25 of the motor shaft 22 and a concave fit with the brush 33, the material fit strength of the brush 33 can be improved, and the service life of the brush 33 can be increased. This concave-convex fit can also reduce the axial and radial runout of the motor shaft 22.

[0019] Furthermore, to overcome the problem that the outer diameter of the motor shaft 22 is smaller than that of the brush 33, such as... Figure 3 As shown, the motor shaft 22 is also fixed with a shaft expansion outer diameter component 23 to accommodate a larger outer diameter of the brush 33. The shaft expansion outer diameter component 23 can also be manufactured as a single piece with the motor shaft 22.

[0020] Furthermore, a brush assembly 3 is also provided at the second end of the motor shaft 22. The dual brush assembly 3 structure has two brush contact positions, which makes the contact more reliable and can be used for testing and grounding respectively, and also makes it easier to reduce the axial and radial runout of the motor shaft 22.

[0021] The first and second ends of the motor shaft 22 simply mark the two opposite end faces of the motor shaft 22.

[0022] Example 2: Figure 1 and Figure 4 The diagram illustrates a brush structure for an electric motor that slides axially with a rotating shaft. It includes a motor mounting component 1, a motor rotating component 2, and a bearing 4 that dynamically connects the mounting component 1 and the rotating component 2. The motor mounting component 1 includes a motor housing 11 and a motor stator 12. The motor rotating component 2 includes a motor rotor 21 and a motor shaft 22. It also includes a brush component 3, which comprises a brush holder 31 fixed to the end face of the first end of the motor shaft 22 on the motor housing 11. The brush holder 31 accommodates a compression spring 32 and a brush 33. The key feature is that the motor shaft 22 has an integrally smooth recessed structure 26 along its rotation axis 25. One end of the brush 33 is compressed by the compression spring 32, causing the other end of the brush 33 to be close to the axial end face of the motor shaft 22. The outer diameter of the brush 33 is within the range of the outer diameter of the motor shaft 22, ensuring that the unworn edge of the brush 33 does not affect the contact between the brush 33 and the rotation axis 25 of the motor shaft 22.

[0023] Preferably, initially, the end face of the brush 33 that contacts the motor shaft 22 along the rotation axis 25 has a protrusion, so that the motor shaft 22 and the brush 33 are basically positioned when the brush 33 is initially installed and used.

[0024] In detail, the brush component 3 illustrated in this embodiment is a strip brush. Other existing brush forms and fixing methods, such as arc brushes and their fixing methods, are also included in the scope of protection of this application.

[0025] In detail, the motor shaft 22 shown in this embodiment has an integral smooth recessed structure 26 along the rotation axis 25. This is a variety of smooth recessed forms to improve the structural strength of the brush 33. The overall meaning is most or all of the area of ​​the axial end face.

[0026] The technical effect of this embodiment is that by forming an integral recessed structure 26 along the rotation axis 25 of the motor shaft 22 and engaging with the protrusion of the brush 33, the material fit strength of the brush 33 can be improved, and the service life of the brush 33 can be increased. This fit method can also reduce the axial and radial runout of the motor shaft 22.

[0027] Furthermore, to overcome the problem that the outer diameter of the motor shaft 22 is smaller than that of the brush 33, such as... Figure 5 As shown, the motor shaft 22 is also fixed with a shaft expansion outer diameter component 23 to accommodate a larger outer diameter of the brush 33. The shaft expansion outer diameter component 23 can also be manufactured as a single piece with the motor shaft 22.

[0028] Furthermore, a brush assembly 3 is also provided at the second end of the motor shaft 22. The dual brush assembly 3 structure has two brush contact positions, which makes the contact more reliable and can be used for testing and grounding respectively; it also makes it easier to reduce the axial and radial runout of the motor shaft 22.

[0029] Declaration: The preferred embodiments of this application have been described above by way of example. The scope of protection of this application is not limited to the contents directly described in the above-described invention and embodiments. Those skilled in the art can obtain technical solutions through logical analysis, reasoning, or limited experimentation based on the technical concepts disclosed in this application without creative effort, or make any simple modifications, equivalent changes, or alterations, all of which should fall within the scope of protection of the technical solutions of this application.

Claims

1. A brush structure for a motor that slides in axial contact with a motor shaft, comprising a motor shaft (22), a brush assembly (3), the brush assembly (3) comprising a brush and a brush clamping and pressing component fixed on a motor housing (11) near the end face of the first end of the motor shaft (22), wherein one end of the brush is close to the axial end face of the motor shaft (22), characterized in that, The motor shaft (22) has a protruding structure (24) along the rotation axis (25), and the outer diameter of the brush is within the range of the outer diameter of the motor shaft (22).

2. The brush structure of a motor that slides in axial contact with a rotating shaft according to claim 1, characterized in that, The motor shaft (22) is also fixed with a shaft extension outer diameter component (23) such that the outer diameter of the shaft extension outer diameter component (23) covers the outer diameter of the brush.

3. The brush structure of a motor that slides in axial contact with a rotating shaft according to claim 1, characterized in that, The second end of the motor shaft (22) is also equipped with a brush component (3).

4. A brush structure for a motor that slides in axial contact with a rotating shaft, comprising a motor rotating shaft (22), a brush assembly (3), the brush assembly (3) comprising a brush and a brush clamping and pressing component fixed on a motor housing (11) near the end face of the first end of the motor rotating shaft (22), wherein one end of the brush is close to the axial end face of the motor rotating shaft (22), characterized in that, The motor shaft (22) has an integrally smooth concave structure (26) along the rotation axis (25), and the outer diameter of the brush is within the range of the outer diameter of the motor shaft (22).

5. The brush structure of a motor that slides in axial contact with a rotating shaft according to claim 1, characterized in that, The motor shaft (22) is also fixed with a shaft extension outer diameter component (23) such that the outer diameter of the shaft extension outer diameter component (23) covers the outer diameter of the brush.

6. The brush structure of a motor that slides in axial contact with a rotating shaft according to claim 1, characterized in that, The second end of the motor shaft (22) is also equipped with a brush component (3).

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