CN218897117U

CN218897117U - Outer rotor structure for direct-current brushless motor

Info

Publication number: CN218897117U
Application number: CN202222926324.0U
Authority: CN
Inventors: 陈召龙
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-11-03
Filing date: 2022-11-03
Publication date: 2023-04-21
Anticipated expiration: 2032-11-03

Abstract

The utility model discloses an outer rotor structure for a direct current brushless motor, which comprises a round magnet and a shaft core, wherein the round magnet comprises a central part, an outer magnetic ring and a plurality of ribs which are connected between the central part and the outer magnetic ring and are distributed at intervals along the circumferential direction, the shaft core is connected to the center of the central part, the round magnet is integrally molded by injection molding, and the inner wall surface of the outer magnetic ring is magnetized by a magnetizing device to form N poles and S poles which are distributed at intervals.

Description

Outer rotor structure for direct-current brushless motor

Technical Field

The utility model relates to the technical field of motors, in particular to an outer rotor structure for a direct current brushless motor.

Background

The outer rotor of the current market direct current brushless motor generally comprises an outer iron shell A, an injection molding magnetic ring B and a shaft core C, wherein during assembly, the shaft core C is pressed into an inner hole in the center of the outer iron shell A, then the injection molding magnetic ring B is pressed on the inner side of the outer iron shell A, the outer iron shell A plays a role of connecting the shaft core C with the injection molding magnetic ring B, and high-temperature glue is needed in the process of pressing the injection molding magnetic ring B on the inner side of the outer iron shell A. The existing outer rotor structure has high precision requirement on the outer iron shell, and has the defects of high cost, poor precision control, complicated working procedures and low competitive power of the product market.

Accordingly, there is a need for an improvement over the prior art to overcome the deficiencies described in the prior art.

Disclosure of Invention

The present utility model aims to solve at least one of the problems of the related art to a certain extent, and therefore, an object of the present utility model is to provide an outer rotor structure for a brushless dc motor, which has a simple structure and is beneficial to reducing the product cost.

The above purpose is achieved by the following technical scheme:

the utility model provides an external rotor structure for DC brushless motor, includes circular magnet and axle core, wherein circular magnet include central part, outer magnetic ring and connect in a plurality of circumferentially spaced apart rib between the central part with outer magnetic ring, the axle core connect in the center of central part, circular magnet is injection molding integrated into one piece, magnetizes with forming N pole and the S pole of interval distribution through magnetizing device in the inner wall surface of outer magnetic ring.

In some embodiments, the outer wall of the outer magnetic ring is in a circumferential wave shape, the wave-shaped convex point is the center point of the N pole or the S pole, and the wave-shaped concave point is the boundary point of the N pole and the S pole.

In some embodiments, knurling is provided on the outer peripheral surface of the shaft core, the knurling of the shaft core being embedded within the central portion.

In some embodiments, an outwardly extending projection is provided at the bottom of the central portion, and the knurling of the shaft core is embedded within the central portion and the projection.

In some embodiments, a connecting part is arranged at the outer end of the rib in an inclined way from inside to outside, and the outer end of the connecting part is connected with the outer magnetic ring.

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

1. the outer rotor structure for the direct current brushless motor is simple in structure and beneficial to reducing the product cost.

Drawings

Fig. 1 is a schematic structural diagram of an outer rotor of a brushless dc motor in the background art;

FIG. 2 is a schematic perspective view of an outer rotor in an embodiment;

FIG. 3 is an exploded schematic view of the outer rotor in an embodiment;

fig. 4 is a schematic perspective view of a shaft core in an embodiment.

Detailed Description

The following examples illustrate the utility model, but the utility model is not limited to these examples. Modifications and equivalents of some of the technical features of the specific embodiments of the present utility model may be made without departing from the spirit of the present utility model, and they are all included in the scope of the claimed utility model.

Embodiment one: as shown in fig. 2, 3 and 4, the present embodiment provides an outer rotor structure for a dc brushless motor, which includes a circular magnet 1 and a shaft core 2, wherein the circular magnet 1 includes a central portion 11, an outer magnetic ring 12, and a plurality of ribs 13 connected between the central portion 11 and the outer magnetic ring 12 and distributed at intervals along a circumferential direction, the shaft core 2 is connected to a center of the central portion 11, the circular magnet 1 is integrally molded by injection molding, and is magnetized on an inner wall surface of the outer magnetic ring 12 by a magnetizing device to form N poles 121 and S poles 122 distributed at intervals.

The outer rotor structure for the direct current brushless motor is simple in structure and beneficial to reducing product cost.

Specifically, during production, the shaft core 2 is inserted into an injection magnetic mold and is integrally formed through injection magnetic. Thereby saving the iron shell and saving the shaft core pressing and magnet pressing process. The cost can be reduced by about 15%, so that the market competitiveness of the product can be greatly improved.

In the production process, the shaft core 2 is put into an injection magnetic mold in advance, and is injected into a mold cavity to be molded through high-pressure high-temperature magnetic material fluid, so that the round magnet 1 is formed and the connection between the round magnet 1 and the shaft core 2 is formed, and further, an additional iron shell, a shaft core pressing process and a magnet pressing process are not needed.

Then, the inner wall of the outer magnetic ring 12 is magnetized by a specific magnetizing device in the mold, so that a magnetic field is generated to form an N pole 121 and an S pole 122, and the number of magnetic poles (N pole and S pole) of the outer rotor can be changed according to different requirements.

In this embodiment, the outer wall of the outer magnetic ring 12 is in a circumferential wave shape, the wave-shaped protruding point is the center point of the N pole 121 or the S pole 122, the wave-shaped concave point is the boundary point of the N pole 121 and the S pole 122, the structure is simple, and the design can save 10% of raw materials under the condition of meeting the same magnetic force requirement.

Preferably, a knurl 200 is provided on the outer circumferential surface of the shaft core 2, and the knurl 200 of the shaft core 2 is embedded in the central portion 11, so that the torque force of the shaft core 2 can be increased to some extent.

The circular magnet 1 is connected with the shaft core 2 through the rib position during injection molding (the number of the rib positions is not specifically required), the joint of the shaft core 2 and the ribs 13 is provided with knurling or notches, and the design achieves the aim of increasing the torsion of the shaft core 2.

In this embodiment, the bottom of the central portion 11 is provided with the protruding portion 110 extending outwards, and the knurling 200 of the shaft core 2 is embedded in the central portion 11 and the protruding portion 110, so that the structure is simple, the design is reasonable and smart, the connection area between the circular magnet 1 and the shaft core 2 can be increased to a certain extent, and the purpose of increasing the torsion of the shaft core 2 is achieved.

Preferably, the outer end of the rib 13 is provided with a connecting portion 130 that is inclined from inside to outside, and the outer end of the connecting portion 130 is connected with the outer magnetic ring 12, so that the structure is simple, the design is reasonable and smart, and the inner space of the circular magnet 1 can be increased to accommodate the stator assembly.

According to the outer rotor structure provided by the embodiment, the end face of the outer magnetic ring 12 adopts the open design of the ribs, when the outer magnetic ring 12 operates, the ribs 13 drive air circulation in a specific space environment to play a role in heat dissipation of the motor body, and through experimental comparison, the temperature of the motor can be reduced by 18% compared with that of a magnet with the end face seal design, so that the service life of the motor can be prolonged. And the heat dissipation design of the motor is reasonable, the copper wires and the iron cores of the motor can reduce partial consumption, and the aim of saving cost is achieved.

The outer rotor structure provided by the embodiment is applied to various fans such as a floor fan, a desk fan, a bedroom lamp head-shaking fan and the like.

What has been described above is merely some embodiments of the present utility model. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit of the utility model.

Claims

1. An outer rotor structure for a direct current brushless motor is characterized by comprising a round magnet (1) and a shaft core (2), wherein the round magnet (1) comprises a central part (11), an outer magnetic ring (12) and a plurality of ribs (13) which are connected between the central part (11) and the outer magnetic ring (12) and distributed at intervals along the circumferential direction, the shaft core (2) is connected to the center of the central part (11), the round magnet (1) is integrally molded through injection molding, and the inner wall surface of the outer magnetic ring (12) is magnetized through a magnetizing device to form N poles (121) and S poles (122) which are distributed at intervals.

2. An outer rotor structure for a brushless dc motor according to claim 1, wherein the outer wall of the outer magnetic ring (12) is in a circumferential wave shape, the wave-shaped protruding point is a center point of the N pole (121) or the S pole (122), and the wave-shaped concave point is a boundary point of the N pole (121) and the S pole (122).

3. An outer rotor structure for a brushless dc motor according to claim 1, characterized in that knurling (200) is provided on the outer peripheral surface of the shaft core (2), the knurling (200) of the shaft core (2) being embedded in the central portion (11).

4. An outer rotor structure for a brushless dc motor according to claim 3, characterized in that a protruding portion (110) extending outwards is provided at the bottom of the central portion (11), and the knurling (200) of the shaft core (2) is embedded in the central portion (11) and the protruding portion (110).

5. An outer rotor structure for a dc brushless motor according to claim 1, 2, 3 or 4, wherein a connecting portion (130) is provided at an outer end of the rib (13) and is inclined from inside to outside, and an outer end of the connecting portion (130) is connected to the outer magnetic ring (12).