WO2012058859A1

WO2012058859A1 - Electric motor

Info

Publication number: WO2012058859A1
Application number: PCT/CN2011/001511
Authority: WO
Inventors: 陈龙; 陈克银; 邓全伟
Original assignee: 深圳市轴心自控技术有限公司
Priority date: 2010-11-01
Filing date: 2011-09-06
Publication date: 2012-05-10
Also published as: CN101976898A

Abstract

An electric motor comprises a frame (1A), at least two stators (2A) fixed on the frame (1A), an electric motor shaft (3A) extending through a centre axis of the stators, and a rotor (4A) fixed on the electric motor shaft (3A); the stators (2A) are axially opposite to the rotor (4A), and excitation windings (5A) are disposed on the stators (2A) enabling the stators (2A) to generate a repulsive force against the rotor (4A), the magnetic flux generated by the excitation windings (5A) being parallel to the electric motor shaft (3A). When the electric motor is operating, both an attractive force and a repulsive force exist between the stators (2A) and the rotor (4A) at the same time, and these forces are the same in magnitude and direction; therefore the power density of the electric motor is increased, the utilization ratio of the electric motor windings and magnetic circuits is increased, and the torque ripple is reduced.

Description

Instruction manual

Technical field

The invention belongs to the field of electric motors, power electronics and electric drives, and in particular to an electric machine and a mechanical device having the same.

Background technique

The motor is a new-generation speed-regulating motor that utilizes the principle of magnetoresistance. It has excellent performance, simple and robust structure, large braking and low-speed torque, low current, strong overload capability, and high efficiency in a wide speed range. An increasingly widespread application. How to further improve motor efficiency, overload capability and simplify the heat dissipation structure is the direction of engineering and technical personnel.

Invention Patent 1 200680043128.X (Motor) discloses a method of reducing the noise of a radial air gap motor and preventing overheating of the motor. The essence is to design the stator and the rotor with different curvature radius (such as ellipse) shape, so that the gap between the protruding core of the stator core and the protruding magnetic pole of the rotor core is gradually reduced in the air gap of the phase inductance increasing region, and the phase inductance is The air gap in the reduced area gradually increases. Also ensure that the air passage is not filled with resin to prevent the motor from overheating. Although this structure reduces the motor noise, reduces the torque ripple, and facilitates the heat dissipation of the motor, the disadvantages are: (1) increasing the power output requirement of the motor to increase the rate of change of the phase inductance, resulting in phase inductance variation due to an increase in the air gap The rate is reduced, although the torque ripple and motor noise are reduced, but the motor performance is weakened; (2) Although this structure can ensure the air circulation inside the motor, the heat dissipation performance of the motor is improved to some extent, but since the motor is closed, The internal air cannot convect with the outside air, and the internal heat cannot be exchanged with the outside heat, so the heat dissipation performance is limited.

Invention Patent 2 200510010551.7 (short magnetic circuit hybrid excitation motor) discloses a method of embedding a permanent magnet in a motor with a radial air gap, thereby achieving an effect of increasing the space utilization of the motor and reducing the torque pulsation. However, the disadvantages of this method are obvious: permanent magnets have problems such as hysteresis and demagnetization and are expensive, have difficulty in manufacturing and installation, and reduce the effect of torque ripple. If it is not obvious, the motor performance is limited.

Invention Patent 3 200710024615.8 (Axial Motor) discloses an axial air gap motor. Unlike a conventional radial air gap motor, the winding motor generates a magnetic flux direction along the axial direction of the motor instead of Radial. In this way, the stator and the rotor are axially pulled apart, the radial dimension of the motor is reduced, and the energy transmission mode is direct axial transmission, and the energy utilization rate is improved. However, there is still no problem that the conventional motor has a long magnetic circuit and a large iron loss. SUMMARY OF THE INVENTION The present invention is directed to the shortcomings of conventional motors and provides structural improvements to improve the overall performance of the motor.

SUMMARY OF THE INVENTION An object of the present invention is to provide a motor which aims to solve the problem that the existing motor has a low utilization ratio of the motor winding and the magnetic circuit, the power density of the motor is small, and the torque ripple is relatively large. The present invention is achieved in that the motor includes a base, at least two stators fixedly disposed on the base, a motor shaft penetrating the central axis of the stator, and a rotor fixedly disposed on the motor shaft The stator is axially opposed to the rotor, and the stator is provided with a field winding that causes a stator to generate a repulsive force to the rotor, and the magnetic flux generated by the field winding is parallel to the motor shaft.

Preferably, the base comprises a magnetic base or a magnetic base.

Preferably, the stator is U-shaped or C-shaped.

Preferably, the rotor is disposed between two adjacent stators, and the pole-to-number of the stator and the rotor is 6/4 or 8/6 or 12/8.

Preferably, the stator and the rotor are both made of a soft magnetic material.

Preferably, the magnetic isolation plate is disposed in the middle of an adjacent rotor disposed on the magnetic pole base.

In the technical solution disclosed by the present invention, the suction force and the repulsive force are simultaneously existed between the stator and the rotor of the motor, and they are equal in size and in the same direction, thereby improving the power density of the motor and improving the motor compared with the conventional motor. The utilization of windings and magnetic circuits reduces torque ripple. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic view showing the overall structure of a motor according to a first embodiment of the present invention;

Figure 2 is a cross-sectional view showing the structure of a motor according to a second embodiment of the present invention;

3 is a magnetic circuit diagram of a motor according to an embodiment of the present invention;

4 is a perspective exploded view of a motor provided by an embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

Fig. 1 shows the structure of a motor according to a first embodiment of the present invention, and for convenience of explanation, only parts related to the embodiment of the present invention are shown.

The motor provided by the present invention comprises a base 1A, at least two stators 2A fixed to the base 1A, a motor shaft 3A penetrating the central axis of the stator 2A, and a rotor 4A fixed to the motor shaft 3A, the stator 2A and the rotor 4A is opposite in the axial direction. In the present embodiment, the base 1A is made of a magnetically permeable material, and the stator 2A and the rotor 4A are both made of a soft magnetic material such as a silicon steel sheet, and the stator 2A is U-shaped or C-shaped, and each stator 2A is provided with a The field winding 5A which causes the stator 2A to generate a repulsive force to the rotor 4A, the magnetic force of the rotor 4A is generated by the field winding 5A, and the magnetic flux generated by the field winding 5A is parallel to the motor shaft 3A.

During operation of the motor, the field winding is always energized to maintain the rotor 4A with a fixed magnetic field direction. The field winding 5A is energized or de-energized according to the relative position of the rotor 4A and the stator 2A. When the rotor 4A approaches the stator 2A, the field winding 5A is not When the rotor 4A is magnetized by the field magnetoresistance, a suction force is generated between the stator 2A and the rotor 4A, and the rotor 4A gradually approaches the stator 2A. When the rotor 4A passes through the stator 2A, the field winding 5A is energized to generate a magnetic field direction opposite to the rotor 4A, and the stator 2A generates a repulsive force to the rotor 4A, and the phase windings on the stator operate once according to the relative positions of the rotors. Since the torque directions generated by the suction force and the repulsive force are the same, the motor continuously rotates.

Example 2

As shown in FIG. 2, FIG. 3 and FIG. 4, a motor according to a second embodiment of the present invention includes a rotor 1B, a stator 2B, a field winding 3B, a base 4B, a motor shaft 5B, and a magnetic shield 6B. The winding 3B is disposed on the stator 2B. The base 4B is made of a non-magnetic material, the rotor 1B has a flat shape as a whole, and the stator 2B has a U-shape or a C-shape. The rotor 1B and the stator 2B are magnetizers made of a magnetically permeable material, wherein a magnetic isolation plate 6B made of a non-magnetically permeable material is disposed in the middle of the rotor 1B, and the stator 2B and the rotor 1B are axially opposed with a predetermined The gap, the rotor 1B is fixed to the motor shaft 5B, and the two sets of stators 2B are arranged along the axial direction of the motor. The field winding 3B of one stator block 2B forms a two-pole magnetic pole, which is called "one phase". The pole-to-digital matching of the U-shaped stator 2B and the rotor 1B can be in the form of an existing switched reluctance motor such as 6/4, 8/6, 12/8, and the like.

During the operation of the motor, when the rotor 1B approaches the stator pole of the stator 2B, the field winding 3B is energized and energized. According to the principle of minimum reluctance, the stator 2B generates electromagnetic torque to the rotor 1B in an attempt to rotate the rotor 1B to a position where the main axis of the rotor 1B coincides with the main axis of the stator pole of the U-shaped stator 2B, since the magnetic resistance is the smallest, the U-shaped stator 2B A magnetic circuit as shown in Fig. 4 will be formed with the rotor 1B.

When the rotor 1B leaves the U-shaped stator 2B, the field winding 3B is de-energized to avoid reverse electromagnetic torque. In this way, the electric current is energized and de-energized for each phase of the excitation winding, and the motor continuously rotates.

In the motor disclosed in this embodiment, compared with the first embodiment, the base is made of a magnetic material, and a magnetic shield is disposed on the rotor. In this embodiment, the magnetic circuit of the motor adopts an axial air gap layout. To eliminate the unilateral axial tensile force, the motor is symmetrically arranged with two flat rotors 1B, two sets of U-shaped stators 2B and two groups. The field winding 3B, the magnetic isolation plate 6B separates the two rotor blocks 1B, and ensures that the axially opposite U-shaped stator block 2B has no magnetic flux loop. The magnetic lines of force when the motor is working are shown in Figure 3. It can be seen that the magnetic circuit 11 is relatively short, which greatly reduces the motor loss. Due to motor windings and The U-shaped stator is open, easy to convect air, has good heat dissipation effect, greatly simplifies the heat sink, and is easy to manufacture, install and maintain. It can be modularized and suitable for large-scale application.

Since the air gap of the motor provided by the present invention is axial, the stator yoke of the prior art motor is eliminated, and the stator and the rotor directly constitute a magnetic flux loop, the magnetic circuit is short, and the iron loss is low. At the same time, since the field winding, the rotor and the stator are all open structures, the air is easy to form convection, which facilitates the formation of heat exchange, which is very advantageous for preventing the motor from overheating and improving the overload capability of the motor.

In addition, the present invention also provides a wide range of motor applications, such as robots, CNC machine tools, electric vehicles, motion control equipment, power drag and wind power applications, and the disclosed motor can be used.

It is to be understood that those skilled in the art can make modifications and changes in the above-described description, and all such modifications and changes are intended to fall within the scope of the appended claims.

Claims

Claim

What is claimed is: 1. A motor comprising: a base, at least two stators fixedly disposed on the base, a motor shaft extending through a central axis of the stator, and a rotor fixedly disposed on the motor shaft, The stator is axially opposed to the rotor, and the stator is provided with a field winding that causes a stator to generate a repulsive force to the rotor, and the magnetic flux generated by the field winding is parallel to the electronic axis.

2. A machine as claimed in claim 1, wherein the base comprises a magnetic or magnetic base.

The motor according to claim 1 or 2, wherein the stator is U-shaped or C-shaped.

4. The electric machine according to claim 3, wherein: the rotor is disposed between two adjacent stators, and the pole-to-number of the stator and the rotor is 6/4 or 8/6 or 12/8 .

5. The motor of claim 4, wherein: said stator and rotor are each made of a soft magnetic material.

A motor according to claim 5, wherein: said magnetic shield is disposed in the middle of an adjacent rotor disposed on the pole mount.