CN106374705B

CN106374705B - Axial flux permanent magnet machine

Info

Publication number: CN106374705B
Application number: CN201611104587.6A
Authority: CN
Inventors: 张鲁; 寇宝泉; 李伟力; 罗俊; 张赫
Original assignee: Harbin Institute of Technology Shenzhen
Current assignee: Harbin Institute of Technology Shenzhen
Priority date: 2016-12-05
Filing date: 2016-12-05
Publication date: 2020-04-24
Anticipated expiration: 2036-12-05
Also published as: CN106374705A

Abstract

The invention provides an axial flux permanent magnet motor with low eddy current loss, and belongs to the field of motors. The motor adopts an outer rotor structure; the stator comprises a stator frame and two sets of slotless and ironless armature windings, the two sets of armature windings are symmetrically distributed on two sides of the stator frame, and phases of corresponding coils of the two sets of armature windings are different in an electrical angle theta along the circumferential direction. The invention adopts a special armature structure to form the axial flux coreless permanent magnet synchronous motor, and the suppression and the enhancement of electromotive force harmonic waves are realized through the armature structure, thereby reducing the eddy current loss in the permanent magnet when the motor runs at high speed and improving the efficiency of the motor.

Description

Axial flux permanent magnet machine

Technical Field

The invention relates to an axial flux permanent magnet motor, in particular to an axial flux permanent magnet motor with low eddy current loss, and belongs to the field of motors.

Background

The axial flux permanent magnet synchronous motor is also called a disc type permanent magnet synchronous motor, is used as a modern high-performance servo motor and a large-torque direct drive motor, is widely applied to mechanical and electrical integration products such as robots and the like, and starts to replace the traditional servo motor product.

The axial flux permanent magnet synchronous motor has the advantages of short axial size, light weight, small volume and compact structure. Because the permanent magnet is adopted for excitation, the rotor part has no magnetic hysteresis and eddy current loss, and the running efficiency of the motor is high; because the stator and the rotor are symmetrically arranged, the stator winding has good heat dissipation conditions, and high power density can be obtained. The rotor has the advantages of small rotational inertia, small electromechanical time constant, high peak torque and locked-rotor torque, large torque/weight ratio, stable low-speed operation and excellent dynamic performance.

In order to reduce the magnetic resistance of a magnetic circuit, an axial flux permanent magnet synchronous motor is usually manufactured by laminating silicon steel sheets with high magnetic permeability into an iron core, and the iron core has the problems of large size, heavy weight, large loss, large vibration noise and the like.

Disclosure of Invention

In view of the above disadvantages, the present invention provides an axial flux permanent magnet motor with small volume, light weight, low loss and low vibration noise.

The axial flux permanent magnet motor comprises a stator, a rotor and an air gap, wherein the motor adopts an outer rotor structure;

the stator comprises a stator frame and two sets of slotless and ironless armature windings, the two sets of armature windings are symmetrically distributed on two sides of the stator frame, and phases of corresponding coils of the two sets of armature windings are different in an electrical angle theta along the circumferential direction.

Preferably, the electrical angle θ is:

wherein p is₁The number of harmonics desired to be retained for an axial flux permanent magnet machine;

p₂the number of harmonic waves to be eliminated is the number of the harmonic waves to be eliminated of the axial flux permanent magnet motor;

when p is₁<p₂When is not in use, and

odd, offset by an electrical angle θ;

when p is₁<p₂When is not in use, and

even, offset by an electrical angle θ, while the current is reversed;

when p is₁>p₂When is not in use, and

odd, offset by an electrical angle θ, while the current is reversed;

when p is₁>p₂When is not in use, and

even, offset by an electrical angle θ.

Preferably, a cooling water tank is provided in the stator frame.

Preferably, the cooling water tank is located corresponding to armature windings on both sides of the stator frame.

Preferably, the rotor is of a double-rotor structure, the double-rotor structure is symmetrically distributed on two sides of the stator, double air gaps are formed between the double-rotor structure and the stator, and n is an even number greater than zero;

each rotor structure comprises a rotor core and n fan-shaped permanent magnets, wherein the n fan-shaped permanent magnets are bonded on the rotor core and are uniformly distributed along the circumference, the fan-shaped permanent magnets are magnetized in parallel along the axial direction, the polarities of the adjacent fan-shaped permanent magnets on the same rotor are opposite, and the polarities of the fan-shaped permanent magnets axially opposite on the two opposite rotors are opposite.

The axial flux coreless permanent magnet synchronous motor has the advantages that the special armature structure is adopted, the axial flux coreless permanent magnet synchronous motor is formed, and the suppression and the enhancement of electromotive force harmonic waves are realized through the armature structure, so that the eddy current loss in the permanent magnet during the high-speed operation of the motor is reduced, and the efficiency of the motor is improved.

Drawings

Fig. 1 is a schematic structural diagram of a stator.

Fig. 2 is a schematic structural view of the rotor.

Fig. 3 is a schematic diagram of an axial flux permanent magnet machine including the stator of fig. 1 and the rotor of fig. 2.

Fig. 4 is a schematic structural diagram of a stator frame.

Fig. 5 is a structural view of a stator including the stator frame of fig. 4.

Fig. 6 is a schematic diagram of an axial flux permanent magnet machine including the rotor of fig. 2 and the stator of fig. 5.

Detailed Description

The present embodiment is described with reference to fig. 1 to 6, and the axial flux permanent magnet motor of the present embodiment includes a stator, a rotor, and an air gap, and the motor adopts an outer rotor structure;

the stator comprises a stator frame 2 and two sets of slotless and ironless armature windings 1, wherein the two sets of armature windings 1 are symmetrically distributed on two sides of the stator frame 2, and phases of coils corresponding to the two sets of armature windings 1 are different in an electrical angle theta along the circumferential direction.

In the embodiment, the suppression and the enhancement of the electromotive force harmonic are realized by arranging the two sets of armature windings 1 and the electric angle theta, so that the eddy current loss in the permanent magnet during the high-speed operation of the motor is reduced, and the efficiency of the motor is improved.

In a preferred embodiment, the electrical angle θ is:

when p is₁<p₂When is not in use, and

odd, offset by an electrical angle θ;

when p is₁<p₂When is not in use, and

even, offset by an electrical angle θ, while the current is reversed;

when p is₁>p₂When is not in use, and

odd, offset by an electrical angle θ, while the current is reversed;

when p is₁>p₂When is not in use, and

even, offset by an electrical angle θ.

The present embodiment specifically provides how to determine the electrical angle θ and the current direction as needed.

In the preferred embodiment, a cooling water tank is provided in the stator frame 2.

This embodiment reduces the heat loss of the motor.

In the preferred embodiment, the cooling water slots are located to correspond to the armature windings 1 on both sides of the stator frame 2.

As shown in fig. 4, the shape of the stator frame 2 is used for supporting, and the position of the cooling water tank in the stator frame 2 is also used for corresponding to the armature winding, so as to absorb the heat generated during the operation of the armature winding and reduce the heat loss.

In a preferred embodiment, the rotor is a dual-rotor structure, the dual-rotor structure is symmetrically distributed on two sides of the stator, a dual air gap is formed between the dual-rotor structure and the stator, and n is an even number greater than zero;

each rotor structure comprises a rotor core 4 and n fan-shaped permanent magnets 3, the n fan-shaped permanent magnets 3 are bonded on the rotor core 4 and are uniformly distributed along the circumference, the fan-shaped permanent magnets 3 are magnetized in parallel along the axial direction, the polarities of the adjacent fan-shaped permanent magnets 3 on the same rotor are opposite, and the polarities of the fan-shaped permanent magnets 3 opposite to each other in the axial direction on the two opposite rotors are opposite.

This embodiment gives the structure of rotor, through rotor and stator cooperation, realizes the motor function.

Claims

1. An axial magnetic flux permanent magnet motor, the motor comprises a stator, a rotor and an air gap, the motor adopts an outer rotor structure, and the stator comprises a stator frame (2) and two sets of slotless and ironless armature windings ( 1), two sets of armature windings (1) are symmetrically distributed on both sides of the stator frame (2), and it is characterized in that, and the phases of the corresponding coils of the two sets of armature windings (1) differ by electrical angle θ along the circumferential direction;

The electrical angle θ is:

Among them, p ₁ is the harmonic order that the axial flux permanent magnet motor hopes to retain;

p ₂ is the harmonic order to be eliminated by the axial flux permanent magnet motor;

When p ₁ <p ₂ , and

is an odd number, the offset electrical angle θ;

When p ₁ <p ₂ , and

is an even number, offset the electrical angle θ, and the current is reversed at the same time;

When p ₁ >p ₂ , and

is an odd number, offset the electrical angle θ, and the current is reversed at the same time;

When p ₁ >p ₂ , and

is an even number, offset by an electrical angle θ.

2 . The axial flux permanent magnet motor according to claim 1 , wherein a cooling water tank is arranged in the stator frame ( 2 ). 3 .

3 . The axial flux permanent magnet motor according to claim 2 , wherein the positions of the cooling water grooves correspond to the armature windings ( 1 ) on both sides of the stator frame 2 . 4 .

4 . The axial flux permanent magnet motor according to claim 2 , wherein the rotor is a double-rotor structure, the double-rotor structure is symmetrically distributed on both sides of the stator, and a double-air gap is formed between the double-rotor structure and the stator. 5 . , n is an even number greater than zero;

Each rotor structure includes a rotor iron core (4) and n sector-shaped permanent magnets (3). The n sector-shaped permanent magnets (3) are bonded on the rotor iron core (4) and are evenly distributed along the circumference. ) are magnetized in parallel along the axial direction, and the polarities of the adjacent sector-shaped permanent magnets (3) on the same rotor are opposite, and the polarities of the axially opposite sector-shaped permanent magnets (3) on the two rotors are opposite.