CN209963931U

CN209963931U - External rotor motor

Info

Publication number: CN209963931U
Application number: CN201920998717.8U
Authority: CN
Inventors: 余丽梅; 谢培利; 董军; 曾国辉; 王锐
Original assignee: Kinetek De Sheng Foshan Motor Co Ltd
Current assignee: Kinetek De Sheng Foshan Motor Co Ltd
Priority date: 2019-06-29
Filing date: 2019-06-29
Publication date: 2020-01-17
Anticipated expiration: 2029-06-29

Abstract

The utility model discloses an external rotor electric machine. The permanent magnet is a permanent magnet with unequal thickness, a plurality of permanent magnets with unequal thickness are uniformly and annularly arranged on the inner side surface of the rotor magnetic yoke, the stator punching sheets are arranged on the inner sides of the permanent magnets with unequal thickness, a plurality of stator teeth are annularly arranged on the periphery of the stator punching sheets, and the outer side surfaces of the stator teeth are formed by continuous multi-section arc surfaces. The utility model relates to a rationally, the stator is towards the piece and is adopted the design of multistage cambered surface, and be equipped with a plurality of recesses, can optimize air gap magnetic field, reduce the magnetic field harmonic, and effectively reduced tooth's socket torque and torque pulsation, thereby the noise and the vibration of motor operation have been reduced, the permanent magnet both is magnetic energy, also be the magnetic circuit simultaneously, effectively shared the traditional magnetic flux of magnetizing through the rotor yoke closure under the mode, both reduced the requirement of high power output motor to the rotor yoke material, again under equal size, can export higher power, the power density of motor has been improved.

Description

External rotor motor

Technical Field

The utility model relates to the technical field of electric machines, specifically relate to an external rotor electric machine.

Background

The outer rotor motor is compact in design and space-saving, the rotor magnetic yoke is usually made of common steel, the processing and the manufacturing are easy, the relative cost is low, and the outer rotor motor is suitable for wide application. However, the structural characteristics of the motor limit the application of the external rotor motor due to two disadvantages: firstly, the permanent magnet is arranged on the inner side of a rotor magnetic yoke in a blocking mode, the air gap magnetic field harmonic is large, and the load torque pulsation and the noise performance are poor; secondly, the saturation magnetic flux density of the common steel is lower, so that the use of the outer rotor motor and the improvement of the power density are limited.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a reduce external rotor electric machine of motor running noise, vibration.

The purpose of the utility model is realized like this.

The utility model provides an external rotor electric machine, includes stator, permanent magnet and the rotor yoke that is piled up by the stator punching, its characterized in that: the permanent magnet is the permanent magnet of unequal thickness, and the even annular of rotor yoke medial surface sets up a plurality of unequal thickness permanent magnet, stator punching is arranged in unequal thickness permanent magnet inboard, and stator punching periphery annular is provided with a plurality of stator teeth, and the lateral surface of stator tooth comprises the multistage cambered surface.

The technical scheme can be further perfected as follows.

More specifically, the outer side surface of the stator punching sheet is provided with a groove.

More specifically, two grooves are arranged on the outer side surface of each stator tooth, the two grooves are arranged in bilateral symmetry with the central axis of the stator tooth, and the electrical angle between the grooves and the central axis of the stator tooth is within 30-75 degrees.

More specifically, a closed magnetic circuit is formed between the adjacent permanent magnets with different thicknesses, and the closed magnetic circuit is formed between the adjacent permanent magnets with different thicknesses through a rotor magnetic yoke.

The utility model relates to a rationally, the stator is towards the piece and is adopted the design of multistage cambered surface, and be equipped with a plurality of recesses, can optimize air gap magnetic field, reduce the magnetic field harmonic, and effectively reduced tooth's socket torque and torque pulsation, thereby the noise and the vibration of motor operation have been reduced, the permanent magnet both is magnetic energy, also be the magnetic circuit simultaneously, effectively shared the traditional magnetic flux of magnetizing through the rotor yoke closure under the mode, both reduced the requirement of high power output motor to the rotor yoke material, again under equal size, can export higher power, the power density of motor has been improved.

Drawings

FIG. 1 is an exploded view of one embodiment.

Fig. 2 is an installation schematic of an implementation one.

Fig. 3 is an enlarged view of a portion a in fig. 2.

Fig. 4 is a schematic diagram of a magnetic circuit embodying the first embodiment.

Fig. 5 is an enlarged view of fig. 4 at B.

Fig. 6 is a schematic view of another non-uniform thickness permanent magnet.

Detailed Description

The invention will be further described with reference to the following drawings and examples:

in a first embodiment, referring to fig. 1 to 6, an outer rotor motor includes a stator stacked by stator laminations 1, permanent magnets and a rotor yoke 3, the permanent magnets are unequal-thickness permanent magnets 2, a plurality of unequal-thickness permanent magnets 2 are uniformly and annularly arranged on an inner side surface of the rotor yoke 3, a closed magnetic path is formed between adjacent unequal-thickness permanent magnets 2, and a closed magnetic path is formed between adjacent unequal-thickness permanent magnets 2 through the rotor yoke 3.

The non-uniform thickness permanent magnet 2 refers to a permanent magnet with the middle thickness larger than the edge thickness, and as shown in fig. 6, the other non-uniform thickness permanent magnet 2 is provided, wherein the middle thickness d1 is larger than the edge thickness d 2.

The stator punching sheet 1 is arranged on the inner side of the permanent magnet 2 with different thicknesses, a plurality of stator teeth 10 are annularly arranged on the periphery of the stator punching sheet 1, the outer side surfaces of the stator teeth 10 are formed by multiple sections of arc surfaces 11, two grooves 12 are arranged on the outer side surface of each stator tooth 10, the two grooves 12 are symmetrically arranged on the left and right of the central axis of the corresponding stator tooth 10, the electrical angle between each groove 12 and the central axis of the corresponding stator tooth 10 is within 30-75 degrees, and in the embodiment, the outer side surfaces of the stator teeth 10 are divided into the three sections of arc surfaces 11 by the two. The groove 12 is circular arc-shaped or rectangular or other shapes. The design of the multi-section arc surfaces 11 and the grooves 12 of the stator teeth 10 weakens the peaks on two sides of the flat-top wave, further improves the sine degree of the air gap flux density waveform, controls the content of counter electromotive force harmonic waves below 1%, effectively reduces the cogging torque and the torque pulsation, and accordingly improves the noise and vibration characteristics of the motor.

In the embodiment, the groove 12 is preferably in an arc shape, the unequal-thickness permanent magnets 2 are magnetized by unequal diameters, the unequal-thickness permanent magnets 2 are magnetic energy and are also magnetic circuits, namely part of magnetic flux of the unequal-thickness permanent magnets 2 does not pass through the rotor yoke 3 but forms a closed magnetic circuit with the adjacent unequal-thickness permanent magnets 2, the magnetic flux density of the rotor yoke 3 is reduced, the requirement on the material of the rotor yoke 3 is reduced, higher power can be output under the same size, the power density of the motor is improved, the magnetic flux density at the center of a magnetic pole can be improved by 15% through the design, the magnetic flux density of the rotor yoke is reduced by 25%, a sinusoidal air gap magnetic density waveform is obtained, the back electromotive force THD is less than or equal to 1%, and the vibration and the noise.

Claims

1. The utility model provides an external rotor electric machine, includes stator, permanent magnet and the rotor yoke that is piled up by the stator punching, its characterized in that: the permanent magnet is the permanent magnet of unequal thickness, and the even annular of rotor yoke medial surface sets up a plurality of unequal thickness permanent magnet, stator punching is arranged in unequal thickness permanent magnet inboard, and stator punching periphery annular is provided with a plurality of stator teeth, and the lateral surface of stator tooth comprises the multistage cambered surface.

2. The external rotor electric machine of claim 1, wherein: the outer side surface of the stator punching sheet is provided with at least two grooves, and the grooves divide the outer side surface of the stator teeth into a plurality of sections of arc surfaces.

3. The external rotor electric machine of claim 2, wherein: the outer side surface of each stator tooth is provided with two grooves, the two grooves are arranged in bilateral symmetry with the central axis of the stator tooth, and the electrical angle between the grooves and the central axis of the stator tooth is within 30-75 degrees.

4. The external rotor electric machine according to any of claims 1-3, wherein: and a closed magnetic circuit is formed between the adjacent permanent magnets with different thicknesses, and the closed magnetic circuit is formed between the adjacent permanent magnets with different thicknesses through a rotor magnetic yoke.