CN112671137A

CN112671137A - Brushless motor

Info

Publication number: CN112671137A
Application number: CN202011578578.7A
Authority: CN
Inventors: 钱文晶; 周洪文
Original assignee: Jiangsu Woerson Electronic Technology Co ltd
Current assignee: Jiangsu Woerson Electronic Technology Co ltd
Priority date: 2020-12-28
Filing date: 2020-12-28
Publication date: 2021-04-16
Also published as: WO2022142085A1

Abstract

The invention discloses a brushless motor, which comprises an outer stator unit and an inner rotor unit, wherein the outer stator unit and the inner rotor unit are concentric rings, the outer stator unit comprises a ring-shaped stator framework and a plurality of armature windings arranged on the stator framework, the inner rotor unit comprises a ring-shaped rotor core, a rotor sleeve and a rotor shaft, the rotor core is connected with the rotor sleeve, the rotor sleeve is sleeved on the rotor shaft, the rotor core is arranged on the annular surface close to the outer stator unit, a plurality of rotor teeth and rotor grooves are arranged at intervals along the circumferential direction, permanent magnets are arranged in the rotor grooves, the permanent magnets correspond to the rotor grooves one by one, and the permanent magnets are embedded in the corresponding rotor grooves.

Description

Brushless motor

Technical Field

The invention relates to the technical field of motors, in particular to a brushless motor.

Background

The description of the background of the invention pertaining to the related art to which this invention pertains is given for the purpose of illustration and understanding only of the summary of the invention and is not to be construed as an admission that the applicant is explicitly or implicitly admitted to be prior art to the date of filing this application as first filed with this invention.

The stator of the brushless motor is composed of a magnetic conducting stator framework, an electric conducting stator winding and a plurality of components for fixing an iron core and the winding, the parts are a machine base, an iron core pressing plate, a winding support and the like, in order to reduce the iron loss in a stator framework of the brushless motor, the stator framework is formed by laminating silicon steel sheets with the thickness of 0.5mm, when the outer diameter of the stator framework is more than 1mm, fan-shaped silicon steel sheets are used for splicing a whole circle, when the stator is stacked, the seam of each layer is staggered to reduce the eddy current loss of the iron core, the inner circle of the stator framework is provided with a groove, a stator winding is arranged in the groove, the groove shape of the stator is generally made into an open groove to facilitate wire embedding, the stator winding of the brushless motor is formed by connecting a plurality of coils, each coil is formed by winding a plurality of strands of copper wires, conductors arranged in the groove are pressed and fixed by a groove wedge, the end part of the conductor is fixed by a support, and the stator framework of the brushless motor is pressed and sleeved in a shell.

The inventor of this application discovers, and current brushless motor is at the in-process that uses because the magnetic line of force of the inside permanent magnet of brushless motor can radially extend along the iron core, will take place the phenomenon of magnetic leakage like this at brushless motor pivoted in-process, and then can cause the loss of moment of torsion, the efficiency of reduction brushless motor output that long-time work can be great.

Disclosure of Invention

The embodiment of the invention aims to provide a brushless motor, which solves the problems that magnetic flux lines of permanent magnets in the brushless motor extend along the radial direction of an iron core in the use process of the existing brushless motor, so that magnetic flux leakage occurs in the rotation process of the brushless motor, further torque loss is caused, and the output efficiency of the brushless motor is greatly reduced in long-time operation.

The purpose of the embodiment of the invention is realized by the following technical scheme:

the invention provides a brushless motor, which comprises an outer stator unit and an inner rotor unit, wherein the outer stator unit and the inner rotor unit are concentric rings, the outer stator unit comprises a ring-shaped stator framework and a plurality of armature windings arranged on the stator framework, the inner rotor unit comprises a ring-shaped rotor core, a rotor sleeve and a rotor shaft, the rotor core is connected with the rotor sleeve, the rotor sleeve is sleeved on the rotor shaft, the rotor core is arranged on the annular surface close to the outer stator unit, a plurality of rotor teeth and rotor grooves are arranged at intervals along the circumferential direction, permanent magnets are arranged in the rotor grooves, the permanent magnets correspond to the rotor grooves one by one, and are embedded into the corresponding rotor grooves,

and a magnetism isolating connecting piece is arranged between the rotor core and the rotor sleeve.

Furthermore, a first through groove is formed in one end, close to the rotor sleeve, of the rotor tooth, a first end of the magnetism isolating connecting piece is embedded into the first through groove and fixedly connected with the rotor tooth, and a second end of the magnetism isolating connecting piece is fixed on the rotor sleeve;

and a second through groove is formed in one end, close to the outer stator unit, of the rotor tooth, and a magnetic shoe is arranged in the second through groove.

Further, the magnetic shoe and the magnetism isolating connecting piece are both made of stainless steel materials.

Furthermore, the permanent magnet is of a magnetic shoe structure and is made of a rubidium iron boron permanent magnet material.

Further, the first through groove is a T-shaped groove, the first end of the magnetism isolating connecting piece is formed into a T-shaped part matched with the T-shaped groove, and the T-shaped part is embedded into the T-shaped groove.

Furthermore, a plurality of the magnetism isolating connecting pieces and the rotor shaft sleeve form an integrated punching sheet structure through blanking.

Further, the rotor core is made of silicon steel sheets.

Further, the motor also comprises a shell, the outer stator unit is arranged in the shell, and the rotor shaft is rotatably arranged on the shell through a bearing.

The embodiment of the invention has the following beneficial effects:

the brushless motor is designed by researching the structure and the using process of the traditional brushless motor, the magnetism isolating connecting piece is made of insulating materials, so that magnetic lines of force cannot extend and diffuse towards the magnetism isolating connecting piece in the rotating operation process of the brushless motor, the magnetic leakage situation can be further reduced, the loss magnetic field is further compensated by installing the auxiliary magnetic shoe on the outer edge of the rotor core, and the brushless motor can be ensured to rotate with the maximum efficiency.

Drawings

Fig. 1 is a schematic view of the overall structure of a brushless motor in an embodiment of the present invention;

FIG. 2 is a schematic structural view of a magnetic shield connector in an embodiment of the present invention;

fig. 3 is a schematic structural view of a rotor core in an embodiment of the present invention;

fig. 4 is a schematic structural view of an inner rotor unit in the embodiment of the present invention;

FIG. 5 is a schematic view of magnetic lines of force of a permanent magnet of a prior art brushless motor;

FIG. 6 is a parameter schematic of a prior art brushless motor;

FIG. 7 is a schematic view of magnetic lines of force after the magnetic shoe is installed in the embodiment of the present invention;

FIG. 8 is a parameter diagram after the magnetic shoe is set in the embodiment of the present invention;

FIG. 9 is a schematic view of magnetic lines of force after the magnetic shoes and the magnetic isolation connectors are installed in the embodiment of the present invention;

fig. 10 is a parameter diagram after the magnetic shoe and the magnetism isolating connector are arranged in the embodiment of the invention.

Detailed Description

The present application is further described below with reference to examples.

In the following description, different "one embodiment" or "an embodiment" may not necessarily refer to the same embodiment, in order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art. Various embodiments may be replaced or combined, and other embodiments may be obtained according to the embodiments without creative efforts for those skilled in the art.

As shown in fig. 5-6, magnetic lines of force of the permanent magnet of the brushless motor in the prior art extend and diffuse toward the rotor shaft, so that magnetic flux leakage occurs during the rotation of the brushless motor, which further causes torque loss, and reduces the output efficiency of the brushless motor greatly during long-time operation. The present embodiment provides a brushless motor to solve the above problems.

As shown in fig. 1 to 4, the brushless motor of the present embodiment includes an outer stator unit 1 and an inner rotor unit 2, the outer stator unit 1 and the inner rotor unit 2 are concentric circular rings, the outer stator unit 1 includes a circular stator frame 11 and a plurality of armature windings 12 disposed on the stator frame 11, the inner rotor unit 2 includes a circular rotor core 25, the rotor core 25 is provided with a plurality of rotor teeth 251 and rotor slots 252 at intervals along a circumferential direction on an annular surface adjacent to the outer stator unit 1, permanent magnets 24 are disposed in the rotor slots 252, the permanent magnets 24 are in one-to-one correspondence with the rotor slots 252, the permanent magnets 24 are embedded in the corresponding rotor slots 252, and the rotor core 25 is connected to a rotor shaft 21 by a plurality of magnetism isolating connectors 23; a first through groove is formed in one end, close to the rotor shaft 21, of the rotor tooth 251, a first end of the magnetism isolating connecting piece 23 is embedded into the through groove and fixedly connected with the rotor tooth 251, and a second end of the magnetism isolating connecting piece 23 is fixed to the rotor shaft 21; a second through groove 253 is formed at one end of the rotor teeth 251 close to the outer stator unit 1, and magnetic shoes 254 are arranged in the second through groove 253.

According to one embodiment of the present invention, the magnetic shoe 24 and the magnetism isolating connector 23 are made of stainless steel material.

According to one embodiment of the present invention, the permanent magnet 24 is a magnetic shoe structure and is made of a rubidium-iron-boron permanent magnet material.

In some embodiments of the invention, injection molded parts are filled between the permanent magnets 24 and the rotor core in order to further prevent magnetic leakage. The arrangement can further avoid magnetic flux leakage between adjacent magnetic poles.

According to an embodiment of the present invention, the first through groove is a T-shaped groove, the first end of the magnetism isolating connector 23 is formed as a T-shaped portion 231 matched with the T-shaped groove, and the T-shaped portion 231 is embedded in the T-shaped groove.

In other embodiments of the present invention, a magnetic isolation pad is disposed between the T-shaped portion and the T-shaped groove, and may be a material such as compressed resin, in other embodiments, the compressed resin may be in a hollow design, and the hollow portion may be a vacuum.

According to an embodiment of the present invention, the second end of the magnetic isolation connecting piece 23 is fixedly connected to the rotor shaft 21 by means of a rotor shaft sleeve 22, and the plurality of magnetic isolation connecting pieces 23 and the rotor shaft sleeve 22 are formed into an integrated punching structure by blanking.

According to an embodiment of the present invention, the rotor core 25 is made of a silicon steel sheet.

According to one embodiment of the invention, it further comprises a housing in which the outer stator unit 1 is built, the rotor shaft 21 being rotatably mounted on the housing by means of bearings.

As shown in fig. 7-8, in this embodiment, an auxiliary magnetic shoe is installed on the outer edge of the rotor core to compensate for the lost magnetic field, so as to ensure that the brushless motor can rotate with maximum efficiency.

As shown in fig. 9-10, in this embodiment, the magnetic isolation connector is made of an insulating material, so that the magnetic lines of force cannot extend and diffuse toward the magnetic isolation connector during the rotation operation of the brushless motor, and the occurrence of magnetic flux leakage can be reduced, thereby further improving the output power of the brushless motor.

In some embodiments, the inner wall of the outer stator unit 1 is provided with spaced magnetic poles with opposite polarities, a magnetizer is arranged between two adjacent magnetic poles with opposite polarities, and the magnetizer is arranged between two adjacent magnetic poles with opposite polarities to reduce an air gap space, increase a solid magnetic path channel and improve magnetic flux density, so that magnetic flux leakage is reduced and motor efficiency is improved.

In some embodiments, the brushless motor is controlled by a control system, the control system is installed inside the brushless motor, the control system is provided with a leakage induction module, and when the leakage reaches a set value, the control module sends out a stop signal to control the brushless motor to stop working.

In other embodiments, the induction module is used for inducing by arranging a coil at the magnetic leakage position, when the magnetic leakage reaches a set value, an induced current can be generated, the coil is connected with the switch, and when sufficient current exists, the switch is driven to be disconnected.

In other embodiments, the applicant researches and finds that the leakage flux is related to the internal temperature of the motor, the temperature sensor is arranged in the motor, when the set temperature is reached, the heat dissipation auxiliary module is started to accelerate the heat dissipation in the motor, the heat dissipation auxiliary module controls the working group of the heat dissipation device, for example, a group of heat dissipation devices is normally adopted, and when the temperature rises to reach the set value, the standby heat dissipation device is started.

It should be noted that the above embodiments can be freely combined as necessary. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A brushless motor is characterized by comprising an outer stator unit (1) and an inner rotor unit (2), wherein the outer stator unit (1) and the inner rotor unit (2) are concentric rings, the outer stator unit (1) comprises a circular stator framework (11) and a plurality of armature windings (12) arranged on the stator framework (11), the inner rotor unit (2) comprises a circular rotor iron core (25), a rotor sleeve (22) and a rotor shaft (21), the rotor iron core (25) is connected with the rotor sleeve (22), the rotor sleeve (22) is sleeved on the rotor shaft (21), the rotor iron core (25) is close to the annular surface of the outer stator unit (1), a plurality of rotor teeth (251) and rotor slots (252) are arranged at intervals along the circumferential direction, permanent magnets (24) are arranged in the rotor slots (252), the permanent magnets (24) are in one-to-one correspondence with the rotor slots (252), the permanent magnets (24) are embedded in the corresponding rotor slots (252),

and a magnetism isolating connecting piece (23) is arranged between the rotor iron core (25) and the rotor sleeve (22).

2. The brushless motor according to claim 1, wherein one end of the rotor teeth (251) close to the rotor sleeve (22) is provided with a first through groove, a first end of the magnetism isolating connector (23) is embedded into the first through groove and fixedly connected with the rotor teeth (251), and a second end of the magnetism isolating connector (23) is fixed on the rotor sleeve (22);

one end of the rotor teeth (251) close to the outer stator unit (1) is provided with a second through groove, and magnetic shoes are arranged in the second through groove.

3. The brushless electric machine according to claim 1, wherein the magnetic shoe (254) and the magnetism isolating connector (23) are each made of a stainless steel material.

4. The brushless electric machine according to claim 1, wherein the permanent magnets (24) are of a magnetic shoe construction, made of a rubidium-iron-boron permanent magnetic material.

5. The brushless motor according to claim 1, wherein the first through groove is a T-shaped groove, the first end of the magnetism isolating connector (23) is formed as a T-shaped portion (231) that fits into the T-shaped groove, and the T-shaped portion (231) is fitted into the T-shaped groove.

6. The brushless electric machine according to claim 1, wherein a plurality of the magnetism isolating connectors (23) are formed as an integral piece of a stamped sheet structure with the rotor bushing (22) by blanking.

7. The brushless electric machine according to claim 1, wherein the rotor core (25) is made of silicon steel sheet.

8. The brushless electric machine according to claim 1, further comprising a housing, the outer stator unit (1) being built into the housing, the rotor shaft (21) being rotatably mounted on the housing by means of a bearing.