WO2021017192A1

WO2021017192A1 - Brushless motor and electrical equipment

Info

Publication number: WO2021017192A1
Application number: PCT/CN2019/111667
Authority: WO
Inventors: 李国雄; 黄成栋; 胡建; 吕继方; 钟贵烈; 曾路强
Original assignee: 广东威灵电机制造有限公司
Priority date: 2019-07-26
Filing date: 2019-10-17
Publication date: 2021-02-04
Also published as: CN112366879A; CN112366879B

Abstract

A brushless motor (100) and electrical equipment. In the brushless motor (100), conductive sheets (21) are provided at intervals on an outer surface of a bearing bracket (15), a dielectric layer (22) is provided between a conductive sheet (21) and a corresponding bearing bracket (15), so that a capacitor is formed between the conductive sheet (21) and the bearing bracket (15); the conductive sheet (21) is electrically connected to a stator iron core (121), which is equivalent to a capacitor connected in series between the bearing bracket (15) and the stator iron core (121), further adjusting the capacitive reactance between the bearing bracket (15) and the stator iron core (121), so as to balance and adjust the electric potential between an inner ring and an outer ring of a bearing (14), reduce the potential difference between the inner ring and the outer ring of the bearing (14), and reduce the shaft voltage, avoiding galvanic corrosion.

Description

Brushless motors and electrical equipment

This application claims the priority of the patent application of the People’s Republic of China filed at the Patent Office of the People’s Republic of China on July 26, 2019, the application number is 201910684726.4, and the invention title is "brushless motors and electrical equipment", the entire contents of which are incorporated by reference Incorporated in this application.

Technical field

This application belongs to the field of motors, and more specifically, relates to a brushless motor and electrical equipment using the brushless motor.

Background technique

The statements here only provide background information related to this application, and do not necessarily constitute prior art. In recent years, due to the energy-saving trend of air conditioning units, high-efficiency brushless DC motors have been used to replace induction motors to drive fans. These brushless DC motors are generally driven by inverters, which use pulse width modulation (Pulse Width Modulation) method (hereinafter referred to as PWM) is used as the driving method. When using the PWM driving method, because the neutral point potential of the winding is not zero, a common mode voltage will be generated; in the case of high frequency, a coupling capacitance will be generated between the various structures of the motor, and this common mode voltage will pass Coupling capacitors between the stator, rotor, permanent magnets, bearing brackets, and bearing capacitors form a loop, which will generate voltage between the inner and outer rings of the bearing (bearing capacitor branch). This voltage generated between the inner and outer rings of the bearing due to the common mode voltage is called the shaft voltage. The shaft voltage contains the high-frequency components of the high-speed switching action of the semiconductor during PWM driving. If the shaft voltage reaches the insulation breakdown voltage of the lubricating oil film inside the bearing, it will discharge and generate current, which will cause partial melting of the inner surface of the bearing and the balls. Corrosion phenomenon, that is, electric corrosion (also called electric corrosion) occurs inside the bearing. When the electrical corrosion is aggravated, wave-shaped wear will occur inside the bearing, such as the inner ring, outer ring or balls of the bearing, causing abnormal noise and shortening the life of the bearing.

technical problem

The purpose of the embodiments of the present application is to provide a brushless motor to solve the problem in the related art that the shaft voltage of the brushless motor is too high, which causes electric corrosion of the bearing.

Technical solutions

In order to achieve the above objective, the technical solution adopted in the embodiments of the present application is to provide a brushless motor, which includes a housing with insulating properties, a stator fixed in the housing, and a rotor rotatably placed in the stator, The stator includes a stator iron core and windings wound on the stator iron core. The rotor includes a rotor core and a rotating shaft penetrating the center of the rotor core. Bearings are sleeved, bearing brackets for fixing two bearings are respectively installed at both ends of the casing, and conductive sheets are arranged on the outer surface of at least one of the bearing brackets. A dielectric layer is arranged between the bearing brackets, and the conductive sheet is electrically connected with the stator core.

Another objective of the embodiments of the present application is to provide an electrical device including the brushless motor as described above.

Beneficial effect

The above one or more technical solutions in the embodiments of this application have at least one of the following technical effects:

In the brushless motor, conductive sheets are arranged on the outer surface of the bearing bracket at intervals, and a dielectric layer is arranged between the conductive sheets and the corresponding bearing bracket, so that a capacitance is formed between the conductive sheets and the bearing bracket, and the conductive sheets and the stator The iron core is electrically connected, which is equivalent to connecting a capacitor in series between the bearing bracket and the stator iron core, thereby adjusting the capacitive reactance between the bearing bracket and the stator iron core to balance and adjust the potential between the inner ring and the outer ring of the bearing to reduce The potential difference between the inner ring and the outer ring of the bearing reduces the shaft voltage and avoids galvanic corrosion.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings that need to be used in the embodiments or exemplary technical descriptions. Obviously, the drawings in the following description are only for the present application. For some embodiments, those of ordinary skill in the art can obtain other drawings based on these drawings without creative work.

1 is a schematic cross-sectional structure diagram of a first brushless motor provided by an embodiment of the application;

2 is a schematic diagram of the three-dimensional structure of the brushless motor of FIG. 1;

Fig. 3 is a schematic structural diagram of a stator core in the brushless motor of Fig. 1;

Fig. 4 is a schematic diagram of the structure of the conductive pin in Fig. 3.

FIG. 5 is a schematic diagram of a three-dimensional structure of a second brushless motor provided by an embodiment of the application.

FIG. 6 is a schematic diagram of a three-dimensional structure of a third brushless motor provided by an embodiment of the application.

FIG. 7 is a schematic cross-sectional structure diagram of a fourth brushless motor provided by an embodiment of the application.

8 is a schematic cross-sectional structure diagram of a fifth brushless motor according to an embodiment of the application;

9 is a schematic diagram of the three-dimensional structure of the brushless motor of FIG. 8;

Fig. 10 is a partial exploded structural diagram of the brushless motor of Fig. 9.

11 is a schematic cross-sectional structure diagram of a sixth brushless motor provided by an embodiment of the application;

FIG. 12 is a schematic diagram of the three-dimensional structure of the brushless motor of FIG. 11.

13 is a schematic cross-sectional structure diagram of a seventh brushless motor according to an embodiment of the application;

FIG. 14 is a schematic diagram of the three-dimensional structure of the brushless motor of FIG. 13.

15 is a schematic cross-sectional structure diagram of an eighth brushless motor provided by an embodiment of the application;

FIG. 16 is a schematic diagram of the three-dimensional structure of the brushless motor of FIG. 15.

FIG. 17 is a schematic cross-sectional structure diagram of a ninth brushless motor provided by an embodiment of the application.

18 is a schematic cross-sectional structure diagram of a tenth brushless motor provided by an embodiment of the application;

FIG. 19 is a schematic diagram of the three-dimensional structure of the brushless motor of FIG. 18.

20 is a schematic cross-sectional structure diagram of an eleventh brushless motor provided by an embodiment of the application.

Among them, the main symbols of the drawings in the figure:

100-brushless motor; 11-chassis; 111-groove; 112-positioning slot; 12-stator; 121-stator core; 122-winding; 123-insulation frame; 1231-inner arm; 1232-outer arm; 13-rotor; 131-rotating shaft; 132-rotor core; 14-bearing; 15-bearing bracket; 151-first bracket; 152-second bracket; 21-conductive sheet; 22-dielectric layer; 23- Conductive arm; 24-conductive pin; 241-sealing ring; 25-conductive cap; 26-conductive piece.

Embodiments of the invention

In order to make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following further describes the application in detail with reference to the drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the application, and are not used to limit the application.

It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "plurality" means two or more than two, unless specifically defined otherwise. The meaning of "several" is one or more than one, unless otherwise clearly defined. In the description of the present invention, it should be understood that the terms "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", " The orientation or positional relationship indicated by "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings, and are only for convenience The present invention is described and simplified description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In the description of this application, it should be noted that the terms "installation", "connection", and "connection" should be interpreted broadly unless otherwise clearly specified and limited. For example, it can be a fixed connection or a detachable connection. Connected or integrally connected; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication between two components or the interaction between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

Please refer to FIG. 1 and FIG. 2, the brushless motor 100 provided in the present application will now be described. The brushless motor 100 includes a casing 11, a stator 12, a rotor 13, two bearings 14 and two bearing brackets 15. Both the stator 12 and the rotor 13 are installed in the casing 11, and the stator 12 is used to drive the rotor 13 to rotate. Two bearings 14 are installed on the rotor 13 to support the rotor 13. The two bearing brackets 15 respectively support the two bearings 14 and then the rotor 13; at the same time, the two bearing brackets 15 are installed on the machine respectively. Both ends of the casing 11 are used to support the rotor 13 in the casing 11 so that the rotor 13 can rotate flexibly. The use of the bearing bracket 15 to support the bearing 14 can more stably support the bearing 14 and ensure that the bearing 14 rotates well.

The casing 11 has insulating properties and plays a major role of support and protection. The casing 11 can be injection-molded using resin materials to facilitate processing and manufacture, and can have a good insulation effect. At the same time, the casing 11 can also dissipate heat. Of course, in order to improve the heat dissipation efficiency, some heat dissipation fins may be provided on the casing 11.

The stator 12 includes a stator core 121 and a winding 122. The winding 122 is wound on the stator core 121. When a current flows through the winding 122, a magnetic field is generated, which is reinforced and guided by the stator core 121. The stator core 121 is formed by stacking several silicon steel sheets to reduce eddy currents. The stator core 121 generally includes a plurality of tooth-like structures, and a winding 122 is wound on each tooth. These tooth-like structures surround a ring, so that the rotor 13 can be placed in the stator 12 to drive the rotor 13 to rotate.

3, in order to firmly connect the winding 122 with the stator core 121 and facilitate the installation of the winding 122 on the teeth of the stator core 121, an insulating skeleton 123 can be provided to support the winding 122, and the insulating skeleton 123 is fixed on the stator On the core 121. Of course, in order to facilitate the connection between the driving circuit and the winding 122, the lead end of the winding 122 may be fixed on the insulating frame 123 to facilitate the connection with the driving circuit.

Further, in one embodiment, the insulating frame 123 has an inner arm 1231 and an outer arm 1232. Along the radial direction of the stator core 121, the inner arm 1231 is located at the inner side of the positioning iron core, and the outer arm 1232 is located at the stator iron core 121. The outside position. The inner arm 1231 and the outer arm 1232 are provided to prevent the winding 122 from falling off when the winding 122 is wound. In addition, when installed in the casing 11, or when the stator 12 and the casing 11 are injection molded into one body, the stator core 121 and the winding 122 can be supported.

The rotor 13 includes a rotating shaft 131 and a rotor core 132. The rotating shaft 131 passes through the center of the rotor core 132 to support the rotor core 132 through the rotating shaft 131. The rotor core 132 is placed in the stator 12 so that when the winding 122 is energized, the stator iron An alternating magnetic field is generated on the core 121 to drive the rotor core 132 to rotate and drive the rotating shaft 131 to rotate. Further, the rotor core 132 may adopt a combined structure of the iron core of the rotor 13 and the magnet, or may be formed by casting a silicon steel sheet into aluminum after being punched out of a squirrel cage shape by stacking.

Both bearings 14 are sleeved on the rotating shaft 131, and the two bearings 14 are respectively located at two ends of the rotor core 132. Since the weight of the rotor 13 is mostly concentrated at the position of the rotor core 132, the center of gravity of the rotor 13 is also at the position corresponding to the rotor core 132, so that the two bearings 14 are respectively arranged at the two ends of the rotor core 132, which can better support The rotating shaft 131 is held to support the rotor core 132 so that the rotor core 132 and the rotating shaft 131 can rotate more smoothly. The two bearings 14 are provided to support the rotating shaft 131 so that the rotating shaft 131 can rotate more flexibly.

The two bearings 14 are respectively placed in the two bearing brackets 15 so as to support the corresponding bearings 14 through the two bearing brackets 15 and thereby support the rotor 13. The two bearing brackets 15 are respectively installed at the two ends of the casing 11 to support the rotor 13 in the casing 11 and enable the rotor 13 to rotate flexibly in the casing 11, and the stator core 121 and each bearing support The frame 15 is insulated. The bearing bracket 15 can support the bearing 14 more stably, ensure the smooth rotation between the outer ring and the inner ring of the bearing 14, and can reduce vibration, avoid the creep of the bearing 14, and make the outer ring of the bearing 14 and the bearing support The frame 15 is electrically connected. The “electrical connection” refers to the ability to conduct electricity, and is not limited to the fact that there must be current flowing between the two at any time. For example, it can be a metal bearing bracket 15 and a metal bearing 14 The contact state between the outer rings.

1 and 2, in one embodiment, the stator 12 and the casing 11 are plastic-sealed into an integral structure, so that the stator 12 is firmly and stably fixed in the casing 11, and the casing 11 can be made relatively small. The volume and weight of the brushless motor 100 produced are reduced. For example, when the casing 11 is made by injection molding, the stator 12 can be placed in a mold, so that when the casing 11 is injection-molded, the casing 11 and the stator 12 form an integrated structure. Of course, in some other embodiments, the casing 11 can also be manufactured separately, and then the stator 12 is fixed in the casing 11.

Referring to FIGS. 1 and 2, in one embodiment, the brushless motor 100 further includes a conductive sheet 21, and the conductive sheet 21 is used to coordinately adjust the capacitive reactance between the stator core 121 and the bearing bracket 15. The outer surface of at least one bearing bracket 15 is provided with conductive sheets 21 at intervals, and a dielectric layer 22 is provided between the conductive sheet 21 and the corresponding bearing bracket 15, so that the bearing bracket 15 and the conductive sheet 21 form a capacitor; The conductive sheet 21 is electrically connected to the stator core 121, which is equivalent to connecting a capacitor in series between the bearing bracket 15 and the stator core 121. By adjusting the capacitance between the conductive sheet 21 and the corresponding bearing bracket 15, it can be To adjust the capacitive reactance between the stator core 121 and the bearing bracket 15, that is, adjust the capacitive reactance between the stator core 121 and the outer ring of the bearing 14. Make the equivalent capacitance between the stator core 121 and the inner ring of the bearing 14 be close to or equal to the equivalent capacitance between the stator core 121 and the outer ring of the bearing 14, that is, balance the equivalent capacitance between the stator core 121 and the inner ring of the bearing 14 And the equivalent capacitance between the stator core 121 and the outer ring of the bearing 14 to balance the potentials of the outer ring of the bearing 14 and the inner ring of the bearing 14 so that the potentials of the outer ring of the bearing 14 and the inner ring of the bearing 14 are similar, reducing the outer ring of the bearing 14 The potential difference between the ring and the inner ring of the bearing 14 is used to reduce the shaft voltage and prevent the bearing 14 from electrolytic corrosion. The dielectric layer 22 may be an insulating layer made of a dielectric material.

Further, a conductive pin 24 is provided in the housing 11, one end of the conductive pin 24 is electrically connected to the stator core 121, the other end of the conductive pin 24 is connected to the conductive arm 23, and the conductive arm 23 is electrically connected to the conductive sheet 21, thereby connecting The conductive sheet 21 is electrically connected to the stator core 121, and this structure facilitates the electrical connection of the conductive sheet 21 and the stator core 121. Specifically, the conductive arm 23 may be a conductive tape, a conductive wire, a conductive sheet 21 or a conductive paper with conductive characteristics. The conductive pin 24 may be a metal pin structure, a metal rod-shaped structure, or a metal strip-shaped structure.

In some other embodiments, wires can also be drawn from the casing 11 to be electrically connected to the conductive sheet 21. In some other embodiments, when the stator core 121 and the casing 11 are made, while the winding 122 is drawn out for connection, the connection end electrically connected to the stator core 121 can also be drawn out, and a wire is used to connect the connection end to the conductive sheet 21 Electrical connection.

1 to 4, in one embodiment, the two bearing brackets 15 are the first bracket 151 and the second bracket 152, respectively, and the first bracket 151 and the second bracket 152 are respectively located in the casing 11 The first bracket 151 is used as the end cover of the casing 11, and the second bracket 152 and the casing 11 are plastic-sealed into an integral structure, that is, when the casing 11 is made by injection molding, the second bracket 152 is placed in a mold. When the casing 11 is injection molded, the second bracket 152 and the casing 11 can be injection molded into one body to ensure that the second bracket 152 is firmly fixed in the casing 11, which facilitates processing and reduces weight ,cut costs. The first bracket 151 is used as the end cover of the casing 11, and the entire end cover can be made of metal, or only the part supporting the bearing 14 can be made of metal to prevent the bearing 14 from creeping and ensure the bearing 14 to rotate stably. The second bracket 152 may only be a part supporting the bearing 14, so that during injection molding, it is convenient to mold the second bracket 152 and the casing 11 into an integral structure.

In the above embodiment, the conductive sheet 21 is provided on the outer peripheral side of the second bracket 152, and the casing 11 extends to the outer peripheral surface of the second bracket 152 and forms the dielectric layer 22. This structure facilitates the arrangement of the conductive sheet 21. Of course, in some embodiments, when the second bracket 152 exposes the casing 11, a dielectric layer 22 may be separately provided on the second bracket 152, and then a conductive sheet 21 may be provided on the dielectric layer 22.

Referring to FIG. 20, in one embodiment, both ends of the casing 11 may be provided in an open structure, and the two bearing brackets 15 may be used as two end cover structures. In this way, a fan and other structures can be installed in one end of the casing 11 to better dissipate heat. Of course, this structure is more practical for motors that require output at both ends of the rotating shaft 131. In addition, if both ends of the casing 11 are set as open structures, and the two bearing brackets 15 are used as end covers, the strength of the brushless motor 100 can be increased through the bearing bracket 15 and the bearing bracket 15 can also be used. Perform heat dissipation to improve heat dissipation efficiency.

Referring to FIGS. 1 and 2, in one embodiment, the conductive arm 23 is attached to the conductive sheet 21. Specifically, one end of the conductive arm 23 is attached to the outer surface of the conductive sheet 21.

Referring to FIG. 5, in one embodiment, the conductive arm 23 may also be a part of the conductive sheet 21, that is, the conductive arm 23 extends from one side of the conductive sheet 21, that is, the conductive arm 23 and the conductive sheet 21 are integrated In structure, the conductive arm 23 is formed by extending the sides of the conductive sheet 21, so that the conductive sheet 21 and the conductive arm 23 can be arranged more conveniently.

Please refer to FIG. 6, in an embodiment, the conductive sheet 21 is attached to the outer surface of the conductive arm 23 to connect the conductive sheet 21 and the conductive arm 23 in a bonding manner.

Referring to FIGS. 1 to 4, in one embodiment, the conductive pin 24 is fixed on the insulating frame 123 to facilitate the installation and fixation of the conductive pin 24 and also to facilitate the connection between the conductive pin 24 and the conductive arm 23. In addition, this structure can conveniently support and fix the conductive pins 24 when the stator 12 and the casing 11 are injection molded into an integral structure.

In the above-mentioned embodiment, the conductive pin 24 is fixed on the inner arm 1231 of the insulating frame 123, and the conductive pin 24 is arranged along the axial direction of the stator core 121 to facilitate fixing the conductive pin 24 and to connect the conductive pin 24 with the conductive The arm 23 is electrically connected.

In the above embodiment, the other end of the conductive pin 24 is provided with a sealing ring 241 in the circumferential direction, that is, the end of the conductive pin 24 far away from the stator core 121 is provided with a sealing ring 241 to facilitate the connection between the stator 12 and the casing 11. Sealing material during injection molding.

In the above embodiment, the other end of the conductive pin 24 extends to the outer surface of the casing 11, that is, the end of the conductive pin 24 away from the stator core 121 extends to the outer surface of the casing 11, so as to facilitate the bonding connection with the conductive arm 23 . Specifically, in this embodiment, the other end of the conductive pin 24 extends to the end surface of the casing 11.

Referring to FIG. 7, in one embodiment, the conductive pin 24 is fixed on the outer arm 1232 of the insulating frame 123, and the conductive pin 24 is arranged along the axial direction of the stator core 121 to facilitate the fixing of the conductive pin 24 and the The conductive pin 24 is electrically connected to the conductive arm 23.

Referring to FIG. 17, in one embodiment, the conductive pin 24 is fixed on the outer arm 1232 of the insulating frame 123, and the conductive pin 24 is arranged along the radial direction of the stator core 121, so that the conductive pin 24 is away from one end of the stator core 121 It extends to the outer circumferential surface of the casing 11, and the conductive arm 23 extends to the outer circumferential surface of the casing 11 to be electrically connected to the conductive pin 24. Of course, in some other embodiments, the conductive pin 24 can be directly fixed in the casing 11. Specifically, the conductive pin 24 may be integrally injection molded with the casing 11 and the stator 12; alternatively, an opening connected to the stator core 121 is provided on the casing 11, and the conductive pin 24 is installed in the opening and connected with The stator core 121 is connected.

Referring to FIGS. 8 to 10, in one embodiment, a conductive cap 25 is installed at the other end of the conductive pin 24, a positioning groove 112 is correspondingly provided on the casing 11, and the conductive cap 25 is installed in the positioning groove 112. Thereby, it is convenient to electrically connect the conductive arm 23 and the conductive cap 25, and further connect the conductive arm 23 and the conductive pin 24 to electrically connect the conductive sheet 21 and the stator core 121.

Please refer to FIG. 10. In one embodiment, the conductive arm 23 may use a metal strip, a metal wire, or a metal belt. Of course, in some embodiments, the conductive arm 23 may also be a structure such as a conductive coating.

In the above embodiment, the conductive arm 23 is a metal sheet separately provided on the casing 11 to facilitate installation and fixation, and to ensure good strength of the conductive arm 23. Further, in the above-mentioned embodiment, the conductive arm 23 may be electrically connected to the corresponding bearing bracket 15 by bonding, riveting, abutting, welding, or the like.

Further, in the above-mentioned embodiment, the housing 11 is provided with a mounting slot, and the conductive sheet 21 is placed in the mounting slot to facilitate the mounting and fixing of the conductive arm 23.

In the above embodiment, the conductive sheet 21 has a ring shape and surrounds the outer peripheral side of the second bracket 152. In some other embodiments, the conductive sheet 21 may also have an arc shape. Specifically, the size and size of the conductive sheet 21 can be adjusted according to needs.

Referring to FIG. 8, in one embodiment, the two bearing brackets 15 are electrically connected, so that the potentials of the two bearing brackets 15 are kept the same, and the potentials of the outer rings of the two bearings 14 are kept the same. As in the above embodiment, the first bracket 151 and the second bracket 152 are electrically connected, so that the electric potential of the first bracket 151 and the second bracket 152 are consistent. In this way, the conductive sheet 21 can adjust the capacitive reactance between the two bearing brackets 15 and the stator core 121 at the same time, and the adjustment is more convenient. Of course, in some embodiments, when the structures of the two bearing brackets 15 are different, the potential difference between the inner and outer rings of the two bearings 14 is also different, and only one of the bearing bracket 15 and the stator core 121 is adjusted. The capacitive reactance between.

In the above-mentioned embodiment, the conductive member 26 may be provided in the casing 11 to electrically connect the two bearing brackets 15. Of course, the conductive member 26 can also be attached from the outside of the casing 11 to electrically connect the two bearing brackets 15, and the conductive member 26 avoids the conductive sheet 21. Specifically, the conductive member 26 may be an elongated metal sheet, metal wire, conductive tape, or the like.

1 and 2, in one embodiment, the capacitance value between the conductive sheet 21 and the corresponding bearing bracket 15 is between 10-100 PF to ensure a good adjustment of the capacitive reactance between the bearing bracket 15 and the stator core 121 , And further adjust the potential difference between the inner ring and the outer ring of the bearing 14 well. If the capacitance between the conductive sheet 21 and the corresponding bearing bracket 15 is less than 10PF, the effect of adjusting the potential difference between the inner ring and the outer ring of the bearing 14 is weak. When the capacitance between the conductive sheet 21 and the corresponding bearing bracket 15 is greater than 100PF, the potential difference between the inner ring and the outer ring of the bearing 14 will be greater. That is, the potential difference between the inner ring and the outer ring of the bearing 14 is still relatively large. Big.

In the above-mentioned embodiment, the conductive sheet 21 is conductive paper, so as to be conveniently attached to the casing 11, and at the same time, it is convenient to cut the size of the conductive sheet 21. Of course, in some embodiments, the conductive sheet 21 can also be a metal foil, for example, copper foil, aluminum foil, etc. can be used.

Referring to FIG. 6, in one embodiment, one side of the conductive sheet 21 is an adhesive surface with conductivity, so that the conductive sheet 21 can be conveniently pasted on the outer peripheral surface of the casing 11 for convenient use. The other side of the conductive sheet 21 is an insulating surface with insulating properties, which can reduce the influence of external devices on the conductive sheet 21, so that the conductive sheet 21 can more stably adjust the capacitive reactance between the stator core 121 and the bearing bracket 15.

5, in an embodiment, the conductive sheet 21 may also be a conductive coating, and a conductive coating is provided on the dielectric layer 22 to form the conductive sheet 21 to ensure that the conductive sheet 21 is firmly fixed on the dielectric layer 22 on. The conductive coating can be made of conductive glue, conductive paste and other materials. Furthermore, the conductive coating can be provided on the dielectric layer 22 by spraying, coating or printing, which facilitates the setting of the conductive coating. In addition, when the conductive sheet 21 and the conductive arm 23 are an integral structure, the conductive sheet 21 is disposed on the dielectric layer 22 by spraying, coating or printing.

Referring to FIGS. 11 and 12, in one embodiment, a groove 111 may be provided on the casing 11, and the groove 111 exposes the stator core 121, so that the conductive arm 23 extends into the groove 111 and conducts electricity. The arm 23 is connected to the stator core 121 to electrically connect the conductive sheet 21 and the stator core 121.

Further, in the above-mentioned embodiment, the above-mentioned groove 111 is provided on the outer peripheral surface of the casing 11. Thereby, the conductive arm 23 is extended to the outer peripheral surface of the casing 11 and is electrically connected to the stator core 121. In some embodiments, a groove 111 may be provided on the end surface of the casing 11, and the conductive arm 23 is electrically connected to the stator core 121 through the groove 111. Of course, in some other embodiments, an opening extending to the stator core 121 may be provided on the casing 11, and conductive curing glue can be filled in the opening, and then the conductive arm 23 can be connected with the curing glue to connect The conductive sheet 21 is electrically connected to the stator core 121.

Referring to Figures 13 and 14, in one embodiment, the peripheral side of a bearing bracket 15 extends to the outer peripheral surface of the casing 11, and a conductive sheet 21 and a dielectric layer 22 are provided on the peripheral side of the bearing bracket 15 at intervals. , To adjust the capacitive reactance between the bearing bracket 15 and the stator core 121.

Referring to Figures 15 and 16, in one embodiment, a conductive sheet 21 and a dielectric layer 22 are respectively provided on the two bearing brackets 15 so that the conductive sheet 21 and the dielectric layer 22 on each bearing bracket 15 are used To adjust the capacitive reactance between the bearing bracket 15 and the stator core 121, and then adjust the potential difference between the inner and outer rings of each bearing 14 to reduce the shaft voltage and prevent the bearing 14 from electrolytic corrosion.

Of course, in other embodiments, the two bearing brackets 15 can also be electrically connected, so that the capacitance of any one of the bearing brackets 15 and the conductive sheet 21 can be adjusted, and the two bearing brackets 15 and the stator core 121 can be adjusted. The capacitive reactance between the two bearing brackets 15 and the stator core 121 can better adjust the capacitive reactance between the two bearing brackets 15 and the stator core 121, and then the potential difference between the inner and outer rings of each bearing 14 , To reduce the shaft voltage.

Referring to FIG. 20, in one embodiment, the peripheral sides of the two bearing brackets 15 extend to the outer peripheral surface of the casing 11, and the peripheral sides of each bearing bracket 15 are provided with conductive sheets 21 and dielectric layers 22 at intervals. In order to adjust the capacitive reactance between the bearing bracket 15 and the stator core 121.

Referring to FIGS. 18 and 19, in one embodiment, the circumferential side of a bearing bracket 15 extends to the outer circumferential surface of the casing 11, and the circumferential side of the bearing bracket 15 is provided with conductive sheets 21 and dielectric layers 22 at intervals , And the conductive sheet 21 and the dielectric layer 22 extend to the outer surface of the bearing bracket 15 so that the capacitive reactance between the bearing bracket 15 and the stator core 121 can be better adjusted. Of course, in some other embodiments, the circumferential sides of the two bearing brackets 15 extend to the outer circumferential surface of the casing 11, and the circumferential sides of each bearing bracket 15 are respectively provided with conductive sheets 21 and dielectric layers 22 at intervals. In addition, each conductive sheet 21 and the corresponding dielectric layer 22 extend to the outer side surface of the corresponding bearing bracket 15, so that the capacitive reactance between each bearing bracket 15 and the stator core 121 can be better adjusted.

The brushless motor 100 of the embodiment of the present application can effectively balance the potential of the inner ring and the outer ring of the bearing 14, reduce the voltage between the inner ring and the outer ring of the bearing 14, avoid galvanic corrosion between the inner ring and the outer ring of the bearing 14, and ensure The brushless motor 100 works well and smoothly, reduces noise and vibration, and prolongs its service life. The brushless motor 100 of the embodiment of the present application may be applied to electrical appliances such as air conditioners, washing machines, microwave ovens, refrigerators, etc.

An embodiment of the present application also provides an electrical device, which includes the brushless motor 100 described in any of the above embodiments. The use of the brushless motor 100 in the electrical equipment can ensure a good lifespan of the brushless motor 100.

The above are only optional embodiments of this application, and are not intended to limit this application. Any modification, equivalent replacement and improvement made within the spirit and principle of this application shall be included in the protection of this application. Within range.

Claims

The brushless motor includes a housing with insulating properties, a stator fixed in the housing, and a rotor rotatably placed in the stator. The stator includes a stator core and a stator core wound on the stator core. Windings, the rotor includes a rotor core and a rotating shaft penetrating the center of the rotor core, the rotating shaft is fitted with bearings at corresponding positions at both ends of the rotor core, and two fixed shafts are installed on both ends of the casing. The bearing bracket of the bearing is characterized in that conductive sheets are arranged on the outer surface of at least one of the bearing brackets at intervals, and a dielectric layer is provided between the conductive sheets and the corresponding bearing brackets. The sheet is electrically connected to the stator core.
The brushless motor of claim 1, wherein the conductive sheet is electrically connected to the stator core through a conductive arm.
The brushless motor according to claim 2, wherein the casing is provided with a groove exposing the stator core, and the conductive arm extends into the groove and is connected to the stator core .
The brushless motor of claim 3, wherein the groove is located on the outer peripheral surface of the casing.
The brushless motor according to claim 2, wherein a conductive pin is provided in the housing, one end of the conductive pin is electrically connected to the stator core, and the other end of the conductive pin is connected to the stator core. The conductive arms are connected.
8. The brushless motor of claim 5, wherein the other end of the conductive pin extends to the outer surface of the casing, and the conductive arm is connected to the other end of the conductive pin in a fit manner.
The brushless motor of claim 5, wherein a conductive cap is installed at the other end of the conductive pin, a positioning groove is correspondingly provided on the housing, and the conductive cap is installed in the positioning groove.
The brushless motor of claim 5, wherein the stator further comprises an insulating frame supporting the winding, the insulating frame is installed on the stator core, and the conductive pin is fixed to the insulating frame. On the skeleton.
The brushless motor according to claim 8, wherein the insulating frame has an inner arm and an outer arm along the radial direction of the stator iron core; the conductive pin is fixed to the stator iron core in the axial direction On the inner arm, or the conductive pin is fixed on the outer arm along the axial direction of the stator iron core, or the conductive pin is fixed on the outer arm along the radial direction of the stator iron core.
3. The brushless motor of claim 2, wherein the conductive arm is formed by extending the conductive sheet.
The brushless motor of claim 2, wherein the two bearing brackets are a first bracket and a second bracket, respectively, the first bracket covers the casing, and the The second bracket is plastic-sealed into an integral structure with the casing, the outer peripheral side of the second bracket is provided with the conductive sheet, and the casing extends to the outer circumferential surface of the second bracket to form the intermediate Electric layer.
The brushless motor according to any one of claims 1-11, wherein the peripheral side of at least one bearing bracket extends to the outer peripheral surface of the casing, and the peripheral side of the bearing bracket is spaced apart The conductive sheet and the dielectric layer are provided.
The brushless motor of claim 11, wherein the conductive sheet and the dielectric layer extend to the outer surface of the bearing bracket.
The brushless motor according to any one of claims 1-11, wherein the conductive sheet and the dielectric layer are respectively provided on each of the bearing brackets.
The brushless motor according to any one of claims 1-11, characterized in that: the housing is provided with a conductive element connecting the two bearing brackets.
The brushless motor according to any one of claims 1-11, wherein one side of the conductive sheet is an adhesive surface with conductivity, and the other side of the conductive sheet is an insulating surface with insulation.
The brushless motor according to any one of claims 1-11, wherein the conductive sheet is a metal foil or conductive paper.
The brushless motor according to any one of claims 1-11, wherein the conductive sheet is a conductive coating, and the conductive coating is disposed on the dielectric layer by spraying, coating or printing. on.
The brushless motor according to any one of claims 1-11, wherein the capacitance value between the conductive sheet and the corresponding bearing bracket is between 10-100 PF.
The electrical equipment is characterized by comprising the brushless motor according to any one of claims 1-19.