CN218920200U - Motor shaft current eliminating structure and motor - Google Patents

Abstract

The utility model discloses a motor shaft current eliminating structure which comprises a mounting cavity arranged on the end face of a rotor rotating shaft, wherein a conductive connecting piece is arranged in the mounting cavity, a carbon brush is arranged at the front end of the conductive connecting piece, and the carbon brush is contacted with the end face of the bottom of the mounting cavity. The utility model also discloses a motor comprising the shaft current eliminating structure. According to the utility model, the carbon brush is arranged at the head part of the conductive connecting piece and is contacted with the end surface of the bottom surface of the installation cavity, and when the rotor rotating shaft rotates at a high speed, the rotation linear speed is greatly reduced due to the contact of the carbon brush with the end surface in the installation cavity, so that the abrasion of the carbon brush is greatly reduced while the shaft current is eliminated; the utility model further provides a closed cavity in the installation cavity, and the sealing column and the sealing ring of the conductive connecting piece are matched to seal the opening part, so that the worn carbon powder cannot fall outside to pollute the inner cavity of the motor.

Description

Motor shaft current eliminating structure and motor

Technical Field

The utility model relates to the technical field of motor shaft current elimination devices, in particular to a motor shaft current elimination structure and a motor comprising the motor shaft current elimination structure.

Background

In the running process of the motor, shaft voltage is generated between a motor stator and a motor rotor due to electromagnetic unbalance, power supply higher harmonic waves and the like; the shaft voltage forms a loop through the motor bearings, producing a shaft current. The existence of shaft current can seriously affect the service life of a motor bearing, so that measures are needed to be taken in motor design to reduce or eliminate the shaft current, thereby guaranteeing the service life of the bearing.

The existing method for eliminating the shaft current mainly comprises the following two steps:

1. the motor adopts the insulating bearing, namely a layer of insulator is attached to the motor bearing, and even if shaft voltage exists between the stator and the rotor during the operation of the motor, shaft current cannot be formed among the motor stator, the rotor and the bearing due to the existence of the insulating layer on the bearing, so that the normal operation life of the bearing is ensured.

2. The grounding carbon brush is arranged on the motor, and is fixedly arranged on the motor stator, and the carbon brush is reliably contacted with the motor rotor; when shaft voltage is generated between the motor stator and the motor rotor, the grounding carbon brush can enable the motor stator and the motor rotor to form a passage through the carbon brush, the resistance of the carbon brush is small, the shaft current forms a loop through the carbon brush, and the shaft current passing through the motor bearing is eliminated, so that the motor bearing is protected.

However, the above structure still has at least the following problems during use:

1. the insulating bearing is high in price, shaft voltage still exists between the stator and the rotor after the motor is installed, and breakdown risk exists in the insulating bearing;

2. the installation of the grounding carbon brush occupies the axial space of the motor, so that the axial size of the motor is increased;

3. the ground carbon brush has high friction linear speed, is seriously worn in the use process and needs frequent maintenance and replacement, but the ground carbon brush is more troublesome to disassemble and assemble;

4. the carbon powder or the brush hair can be polluted in the inner cavity of the motor due to the fact that the carbon powder or the brush hair falls onto the bearing lubricating grease, the lubricating grease can be polluted, the bearing lubricating effect is affected, and then the service life of the bearing is affected.

Disclosure of Invention

The main object of the present utility model is to provide a motor shaft current eliminating structure, which solves the above mentioned problems in the background art.

It is a further principal object of the present utility model to provide an electric motor including the motor shaft current eliminating structure as above.

In order to achieve the above object, the present utility model provides a technical solution:

the utility model provides a motor shaft current elimination structure, includes the installation cavity that sets up in rotor shaft terminal surface, be provided with conductive connection spare in the installation cavity, conductive connection spare's front end is provided with the carbon brush, the carbon brush with installation cavity bottom terminal surface contacts.

Preferably, the installation cavity comprises a carbon brush accommodating cavity and a closed cavity which are communicated, and the conductive connecting piece further comprises a sealing column connected to the end face of the bottom of the carbon brush far away from the installation cavity.

Preferably, the sealing post is sleeved with a sealing ring, and the sealing ring is sealed at the opening end of the closed cavity.

Preferably, the mounting cavity further comprises a fixing cavity communicated with the closed cavity, the shaft current eliminating structure further comprises a cover plate mounted on the motor stator, an internal threaded hole corresponding to the fixing cavity is formed in the cover plate, the conductive connecting piece further comprises an external threaded section connected to the sealing post, and the external threaded section penetrates through the internal threaded hole in a threaded mode and is contained in the fixing cavity.

Preferably, the cover plate is provided with a fixing protruding piece, the fixing protruding piece is located in the fixing cavity, the fixing protruding piece is provided with a penetrating internal thread section, and the external thread section is arranged on the internal thread section in a screwed mode.

Preferably, a spigot structure is arranged on the outer side end surface of the cover plate and corresponds to the conductive connecting piece.

Preferably, the contact surface of the spigot structure is provided with a gasket.

Preferably, the terminal end of the conductive connecting piece is provided with a detaching end.

Preferably, the disassembly end is a hexagonal head.

The utility model provides another technical scheme that:

an electric motor comprising a motor shaft current eliminating structure as described above.

Compared with the prior art, the utility model has at least the following beneficial effects:

1. according to the utility model, the installation cavity is formed in the end face of the rotor rotating shaft, the conductive connecting piece is arranged in the installation cavity, and the carbon brush is arranged at the head part of the conductive connecting piece and is contacted with the end face of the bottom surface of the installation cavity, so that when the rotor rotating shaft rotates at a high speed, the rotation linear speed is greatly reduced due to the contact between the carbon brush and the end face in the installation cavity, and the abrasion of the carbon brush is greatly reduced while the shaft current is eliminated; the utility model further provides a closed cavity in the installation cavity, and the sealing column and the sealing ring of the conductive connecting piece are matched to seal the opening part, so that carbon powder or a broken brush worn by the carbon brush cannot fall outside, and pollution is caused to the inner cavity of the motor;

2. according to the utility model, the end face of the rotor rotating shaft is covered by arranging the cover plate at the end head of the stator, the surface of the cover plate facing the rotor rotating shaft is provided with the fixing protruding piece, the fixing protruding piece is positioned in the mounting cavity, the fixing protruding piece is provided with the internal thread and is in threaded connection with the external thread section of the conductive connecting piece, when the carbon brush needs to be maintained and replaced, the cover plate is only required to be removed, the carbon brush can be maintained and replaced, the whole process is simple to operate, and the treatment time is short.

Drawings

FIG. 1 is a schematic front view in section of a partial structure according to an embodiment of the present utility model;

fig. 2 is a schematic structural cross-section of a conductive connector according to an embodiment of the utility model.

In the figure: 1. a rotor shaft; 2. a conductive connection; 3. a cover plate; 4. a seal ring; 5. a sealing gasket; 11. a mounting cavity; 21. a carbon brush; 22. a sealing column; 23. an external thread section; 24. a spigot structure; 25. disassembling the end head; 31. and fixing the protruding member.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Example 1

Referring to fig. 1 and 2, the present embodiment discloses a motor shaft current eliminating structure, which includes a mounting cavity 11 disposed on an end surface of a rotor shaft 1, a conductive connecting member 2 is disposed in the mounting cavity 11, a carbon brush 21 is disposed at a front end of the conductive connecting member 2, and the carbon brush 21 contacts with a bottom end surface of the mounting cavity 11.

In the prior art, in order to eliminate shaft current generated in the running process of the motor, carbon brushes are arranged on a stator and are contacted with the outer circular surface of a motor rotor opposite to the stator, when the motor rotor rotates at a high speed, the rotation linear speed of the outer circular surface positioned at the outermost side is the highest under the condition that the rotation angular speed is the same, so that the abrasion of the carbon brushes is serious, and the replacement period of the carbon brushes is shorter; meanwhile, since the carbon brush needs to be mounted on the end face of the side portion of the stator, the axial space of the motor needs to be increased, so that the mounting space of the carbon brush is provided, and the overall axial size of the motor is increased.

In this embodiment, the end face of the end of the rotor shaft 1 is provided with the installation cavity 11, the installation cavity 11 is inwards recessed in the end face of the rotor shaft 1, meanwhile, the conductive connecting piece 2 is provided, the front end of the conductive connecting piece 2 is provided with the carbon brush 21, and the carbon brush 21 stretches into the installation cavity 11 to reliably contact with the end face of the bottom of the installation cavity 11. Therefore, when the motor rotor rotates at a high speed, the linear speed of the rotor rotating shaft 1 from the axis to the outer circular surface is continuously increased, and the carbon brush 21 is contacted with the bottom of the installation cavity 11 formed on the end surface of the rotor rotating shaft 1, and the abrasion degree of the carbon brush 21 in the embodiment is also greatly reduced because the rotational linear speed of the installation cavity 11 is greatly reduced compared with the linear speed of the outer circular surface. Preferably, the mounting cavity 11 of the present embodiment is located on the axis of the rotor shaft 1.

Further, referring to fig. 1, the installation cavity 11 of the present embodiment includes a carbon brush accommodating cavity and a closed cavity, which are communicated, the carbon brush accommodating cavity is located at the bottommost part of the end face of the rotor shaft 1, and referring to fig. 2, correspondingly, the conductive connecting member 2 further includes a sealing post 22 connected to a side of the carbon brush 21 away from the carbon brush accommodating cavity. Carbon brush holding chamber and carbon brush 21 cooperate and are used for placing carbon brush 21, and airtight chamber then cooperates with seal post 21, and seal post 21 holding is sealed to the carbon brush holding chamber of bottom in airtight intracavity, avoids carbon brush 21 to use the wearing and tearing after for a long time, and the carbon powder or the disconnected brush that produce get into the motor cavity, fall into in the bearing grease, influence motor bearing's lubrication effect, and then influence bearing use and cause motor trouble. In the prior art, since the carbon brush is in contact with the outer circular surface of the rotor, and the rotor rotates at a high speed, a sealing structure cannot be arranged between the outer circular surface of the rotor and the carbon brush to prevent the carbon brush from entering the inner cavity of the motor.

Preferably, referring to fig. 1 and 2, a sealing ring 4 is sleeved at the rear end (right end) of the sealing post 22, when the sealing post 22 is matched with the closed cavity, the sealing ring 4 is attached around the opening of the closed cavity, and the sealing of the opening end of the closed cavity by the sealing ring 4 is realized by extrusion. Further preferably, referring to fig. 1, a closing structure may be disposed at an opening of the closed cavity, and then the closing part is sealed by using the sealing ring 4, so that an inner space of the closed cavity is large and the closing is small, and the carbon brush 21 and the sealing column 22 are convenient to install and set.

Further, the installation cavity 11 further comprises a fixing cavity communicated with the closed cavity, the shaft current eliminating structure of the embodiment further comprises a cover plate 3 installed on the motor stator, an internal threaded hole corresponding to the fixing cavity is formed in the cover plate 3, the conductive connecting piece 2 further comprises an external threaded section 23 connected to the sealing post 22, and the external threaded section 23 penetrates through the internal threaded hole in a threaded mode and is contained in the fixing cavity.

In this embodiment, the cover plate 3 provides a mounting structure of the conductive connecting member 2, so as to fix the conductive connecting member 2, and prevent the carbon brush 21 from being separated from the bottom surface of the mounting cavity in the use process, so that the shaft current cannot be eliminated. The cover plate 3 of this embodiment may be circular, and is used for covering the end face of the rotor, and can avoid foreign matters from entering the rotor during use, and of course, the cover plate 3 may also be various shapes such as bar shape, square shape, etc., and only the cover plate 3 is required to be fixed on the stator, and the installation fixing position of the conductive connecting piece 2 is provided. Specifically, in this embodiment, the position of the cover plate 3 corresponding to the fixing cavity is provided with a threaded hole, and the conductive connecting piece 2 is connected with the threaded hole by using the external thread section 23, so that the overall fixing of the structure of the conductive connecting piece 2 is realized, and the conductive connecting piece 2 is prevented from shifting during the operation process of the motor.

In addition, the diameter of the external thread section 23 is larger than that of the sealing column 22, the sealing ring 4 is sleeved at the root of the sealing column 22 and is attached to the front end face of the external thread section 23, and when the sealing cavity is used, the extrusion force to the sealing ring 4 can be adjusted by adjusting the screwing depth of the external thread section 23, so that the sealing effect of the sealing cavity is better.

Preferably, the cover plate 3 is provided with a fixing protruding member 31, the fixing protruding member 31 is located in the fixing cavity, the fixing protruding member 31 is provided with a penetrating internal thread section, and the external thread section 23 is screwed on the internal thread section.

In order to make the installation and operation of the conductive connecting piece 2 more stable, the embodiment is based on fixing the cover plate 3 on the stator, and the end surface of the cover plate 3 opposite to the rotor rotating shaft 1 is provided with the fixing protruding piece 31, the shape of the fixing cavity and the shape of the fixing protruding piece 31 are adapted, and the fixing cavity can be various shapes such as a cylinder shape and a polygonal column shape, and only the fixing protruding piece 31 needs to be ensured to conveniently extend into and pull out of the fixing cavity together with the conductive connecting piece 2. The fixing cavity and the fixing protruding piece 31 are utilized to enable the mounting cavity 11 of the rotor rotating shaft 1 and the cover plate 3 to interfere with each other in the radial direction, so that the conductive connecting piece 2 does not shake in the radial direction; meanwhile, compared with the case that the cover plate 3 with constant thickness is provided with the threaded hole, the length of the fixing protruding piece 31 is longer, the embodiment also enables the threaded connection length of the internal thread section to be longer by arranging the internal thread section on the fixing protruding piece 31, the contact length of the external thread section 23 and the internal thread section is increased, and therefore the conductive connecting piece 2 is connected with the cover plate 3 more stably, and vibration falling or shaking cannot occur.

Further, referring to fig. 1 and 2, the outer end surface of the cover plate 3 away from the mounting cavity 11 is provided with a spigot structure 24 corresponding to the conductive connection member 2. Through setting up the negative and positive structure of concave tang and protruding tang, realize the location guiding action to apron 3 and conductive connection 2.

Preferably, the contact surface of the spigot structure 24 is provided with a sealing gasket 5.

Preferably, the extreme end of the conductive connector 2 is provided with a removal tip 25. In this embodiment, the dismounting end is connected to the external thread section 23, so as to facilitate the rotation of the external thread section 23, thereby completing the installation and the dismounting of the conductive connecting piece 2. Illustratively, the removal head 25 is a hex head, although the removal head 25 may have other shapes, such as by mating with an existing or special tool to facilitate threading of the male threaded section 23.

When the motor runs, shaft voltage is generated between the stator and the rotor, the shaft voltage realizes conduction between the stator and the rotor of the motor through the carbon brush 21, the conductive connecting piece 2 and the cover plate 3, so that shaft current flowing through a motor bearing is eliminated, and the bearing is protected. When the carbon brush 21 needs to be maintained or replaced after long-term use, the cover plate 3 is only required to be detached first, and then the carbon brush 21 is maintained and replaced.

In summary, in the existing method for eliminating the shaft current by using the grounding carbon brush, the problems of increasing the axial dimension of the motor, having larger friction linear velocity of the carbon brush, frequent replacement and maintenance, pollution of the inner cavity of the motor due to falling carbon brush carbon powder, inconvenient replacement and maintenance and the like exist. In the embodiment, the conductive carbon brush is arranged on the cover plate and extends into the installation cavity of the end face of the rotor rotating shaft, so that the structure does not need to additionally increase the axial distance of the motor; the friction linear speed of the carbon brush is low when the motor runs, the corresponding abrasion is low, and frequent replacement and maintenance are not needed; by designing the closed cavity, carbon powder is closed in the cavity after falling, so that the inner cavity of the motor and lubricating grease cannot be polluted; meanwhile, the structure of the embodiment is convenient to maintain, replace and disassemble, and only the carbon brush of the head part of the conductive connecting piece is required to be adjusted or replaced by detaching the cover plate.

Example 2

This embodiment discloses a motor including the motor shaft current eliminating structure as described in embodiment 1.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the utility model, the scope of which is defined in the appended claims and their equivalents.

Claims (10)

1. The motor shaft current eliminating structure is characterized by comprising an installation cavity arranged on the end face of a rotor rotating shaft, wherein a conductive connecting piece is arranged in the installation cavity, a carbon brush is arranged at the front end of the conductive connecting piece, and the carbon brush is contacted with the end face of the bottom of the installation cavity.

2. The shaft current eliminating structure according to claim 1, wherein the installation cavity includes a carbon brush accommodation chamber and a closed chamber which are communicated, and the conductive connecting member further includes a seal post connected to an end face of the carbon brush which is away from a bottom end face of the installation cavity.

3. The shaft current eliminating structure according to claim 2, wherein the sealing post is sleeved with a sealing ring, and the sealing ring is sealed at an opening end of the closed cavity.

4. The shaft current elimination structure according to claim 2, wherein the installation cavity further comprises a fixing cavity communicated with the closed cavity, the shaft current elimination structure further comprises a cover plate installed on the motor stator, an inner threaded hole corresponding to the fixing cavity is formed in the cover plate, the conductive connecting piece further comprises an outer threaded section connected to the sealing post, and the outer threaded section penetrates through the inner threaded hole in a threaded mode and is accommodated in the fixing cavity.

5. The shaft current eliminating structure according to claim 4, wherein a fixing protrusion is provided on the cover plate, the fixing protrusion is located in the fixing cavity, a penetrating internal thread section is provided on the fixing protrusion, and the external thread section is screwed on the internal thread section.

6. The shaft current eliminating structure according to claim 5, wherein an outer end surface of the cover plate is provided with a spigot structure corresponding to the conductive connecting member.

7. The shaft current eliminating structure according to claim 6, wherein a contact surface of the spigot structure is provided with a gasket.

8. The shaft current elimination structure according to claim 4, wherein the conductive connection member is provided with a disassembly tip at an extreme end.

9. The shaft current flow elimination structure according to claim 8, wherein said disassembly tip is a hex head.

10. An electric motor comprising the motor shaft current eliminating structure according to any one of claims 1 to 9.

Images