CN204334259U - A rotor segmented reverse oblique polarity double disc permanent magnet motor for electric vehicles - Google Patents

Abstract

The utility model relates to a segmented reverse oblique pole double-disk permanent magnet motor for electric vehicles. The motor is composed of a stator and a rotor; the stator is composed of a back-to-back slotted stator core and an armature winding. The windings span across the stator teeth of the adjacent back-to-back slotted stator core in the circumferential direction; the rotor is a disc rotor with two symmetrically distributed on both sides of the stator. The rotor is composed of a permanent magnet and a rotor yoke. The rotor The yoke is a disc structure, and the permanent magnets are evenly attached to the inside of the rotor yoke, facing the stator, and the permanent magnets are arranged in a corresponding NS structure, so that the permanent magnets are axially magnetized. The utility model utilizes the way of segmented oblique poles of the rotor to maintain a high torque and power density of the permanent magnet motor, and at the same time weaken the tooth harmonics in the back EMF, reduce the cogging torque, and improve the efficiency of the permanent magnet motor further improvement.

Description

A rotor segmented reverse oblique polarity double disc permanent magnet motor for electric vehicles

technical field

The utility model relates to a segmented reverse oblique pole double-disc permanent magnet motor for an electric vehicle rotor, which belongs to the technical field of motor manufacturing.

Background technique

Due to the excessive emission of vehicle exhaust, environmental problems such as carbon dioxide emissions and air pollution are becoming more and more serious around the world. Vigorously developing electric vehicles and allowing electric vehicles to replace traditional fuel vehicles as much as possible is the key to alleviating many environmental problems caused by vehicle exhaust. Effective Ways. Electric vehicles have the advantages of high energy utilization, zero exhaust emissions, and low noise. Electric energy is a real clean energy, and vigorously developing electric vehicles is more suitable for the environment of today's low-carbon economy. However, the most critical technology in the development process of electric vehicles is the working efficiency of its drive motors. The drive motors used in electric vehicles are required to have the advantages of high efficiency, wide speed regulation, stable operation, and low noise.

Electric vehicles require good torque control capability and high torque density for their drive system. Permanent magnet motors have flexible and diverse structures, and have the characteristics of high power density, high torque and high efficiency, and are very suitable for industrial transmission fields such as electric vehicles. The permanent magnet motor can meet the needs of electric vehicles in a wide speed range, and both the motor and the drive controller have high efficiency. Due to the good performance characteristics of rare earth permanent magnet synchronous motors, it has attracted extensive attention from the electric vehicle industry at home and abroad. Most of the newly developed electric vehicles in developed countries use permanent magnet synchronous motors as the drive motors of electric vehicles.

The disc motor has the characteristics of small size, light weight, and compact structure, and its advantages such as high power density and high material utilization rate are not available in radial motors. Radial flux structures widely used in induction motors, synchronous motors, permanent magnet motors and DC motors can be designed as disc motors. The advantages of the permanent magnet synchronous motor and the disc motor are now combined to form a double disc permanent magnet motor, which highlights its advantages in the field of thin-installed electric vehicles.

However, the permanent magnet synchronous motor for electric vehicles needs to provide a stable working environment, in order to minimize the loss, noise and torque ripple of the permanent magnet synchronous motor for electric vehicles, and to optimize the permanent magnet flux density of the no-load air gap Waveform, try to make its waveform sinusoidal. Based on this, the utility model combines the excellent characteristics of the permanent magnet motor and the disc motor, and on the basis of keeping the motor with simple structure, stable operation and high efficiency, it innovatively proposes a segmented oblique pole rotor for electric vehicles double disc permanent magnet motor. The utility model mainly utilizes the way of segmented oblique poles of the rotor to weaken the tooth harmonics of the opposite electric potential of the motor, improve the sine degree of the permanent magnet flux linkage and the induced electromotive force waveform, and effectively reduce the cogging torque and torque ripple of the motor .

Utility model content

Technical problem: The technical problem to be solved by the utility model is to provide a topological structure of the rotor segment oblique pole double-disc permanent magnet motor suitable for electric vehicles. Determine the rotor tilt mode of the motor, explore the influence of the rotor tilt angle and tilt direction on the motor tooth harmonics, and provide a new type of motor that combines the characteristics of the disc permanent magnet motor and can reduce motor loss, noise and cogging torque. Permanent magnet motors for electric vehicles.

Technical solution: a rotor segmented reverse oblique pole double disc permanent magnet motor for electric vehicles, characterized in that the motor is composed of a stator and a rotor (2);

The stator is composed of a back-to-back slotted stator core (1) and an armature winding (5), and the armature winding (5) adopts a concentrated winding and spans across the adjacent back-to-back slotted stator core (1) in the circumferential direction. on the stator teeth;

The rotor (2) is a disk-type rotor with two symmetrically distributed on both sides of the stator. The rotor is composed of a permanent magnet (3) and a rotor yoke (4). The rotor yoke (4) is a disk The permanent magnet (3) is evenly attached to the inside of the rotor yoke (4), facing the stator, and the permanent magnets adopt an N-S corresponding arrangement structure, so that the permanent magnets are axially magnetized.

Utilizing the structural characteristics of the segmented oblique poles of the rotor poles, the tooth harmonics in the back EMF of the motor can be effectively weakened, the cogging torque and torque ripple of the motor can be effectively controlled, and the efficiency of the motor can be significantly improved.

The armature winding (5) adopts a concentrated winding, spans the adjacent stator teeth in the circumferential direction, and the armature winding (5) faces the inside of the two rotor disks, adopting a back-to-back structure.

The rotors (2) of the two-disc structure are symmetrically distributed on both sides of the back-to-back stator core (1). Both the stator and the rotor of the motor are made of wound silicon steel sheets, forming a part of the magnetic flux circuit.

The permanent magnet (3) adopts a segmented inclined pole structure, and the whole permanent magnet is evenly divided into several pieces. The segmented permanent magnets are staggered by a certain displacement to form an oblique angle between the rotor segments. The oblique angle is 0 ~40 electrical angles, the oblique angles between adjacent rotor segments are kept consistent; at the same time, the corresponding segmented permanent magnets on both sides are inclined in opposite directions.

The rotor segment oblique pole double disc permanent magnet motor of the utility model is composed of a stator and a rotor. The stator core of the motor adopts a slotted back-to-back structure. The armature windings are arranged on both sides of the stator core in the circumferential direction. Evenly distributed on the surface of the rotor yoke, the permanent magnets on both sides adopt an arrangement structure corresponding to N poles and S poles, and are made of rare earth permanent magnet material NdFeB; the whole permanent magnet is evenly divided into several pieces, divided into The permanent magnets of each segment are staggered by a certain displacement to form the oblique angle between the rotor segments, and the oblique angles between adjacent rotor segments are kept consistent; the oblique directions of the permanent magnets on the rotor discs on both sides are opposite, providing a more Effectively weaken the back EMF harmonic component and suppress torque ripple; the rotor disk and stator core are made of magnetically conductive materials; the motor shaft is made of nonmagnetically conductive steel.

The specific working principle of the motor is as follows:

When the motor is working, the magnetomotive force is generated by the permanent magnet surface-attached on the rotor disk. The magnetic flux path of the main magnetic flux of the motor is: starting from the N pole of the permanent magnet, passing through the stator core and the air gaps on both sides in the axial direction and entering the opposite pole. The S pole of the side rotor flows along the circumferential direction of the rotor yoke, passes through the N pole of the opposite rotor, and then returns to the S pole of the rotor in the axial direction, as shown in Figure 3. In the utility model, since the magnetic flux directly passes through the middle stator and does not generate circumferential circulation in the stator core, in order to generate electromagnetic torque, the surrounding winding with a simple structure cannot be used.

When the motor performs electromagnetic conversion, it is inevitable to generate tooth harmonics and redundant losses. The eddy current loss of the permanent magnet is reduced by using the rotor segmented oblique pole motor structure, which reduces the temperature of the permanent magnet, and at the same time, the anti-demagnetization ability of the permanent magnet is also significantly improved. The permanent magnets on the rotors on both sides adopt the method of opposite oblique directions, which can weaken the cogging torque of the motor and reduce the torque ripple to the greatest extent.

Both the number of permanent magnet segments and the offset angle have a great influence on the performance of the segmented rotor oblique pole permanent magnet motor. With the increase of segment number and displacement angle, the weakening of cogging torque and torque ripple is more obvious, and the back EMF waveform is more sinusoidal. When the number of segments is large, all low-order harmonics in the cogging torque can be basically suppressed. However, as the number of segments increases, while weakening the tooth harmonics, it will also reduce the main magnetic field of the motor and reduce the output torque. In summary, choosing a reasonable number of segments and offset angles is the key to designing a segmented oblique pole permanent magnet motor for electric vehicles.

Beneficial effects: Due to the novel structure of the rotor segmented oblique pole double disc permanent magnet motor, the motor has the functions of weakening the tooth harmonics of the opposite potential, suppressing the cogging torque and reducing the torque ripple. , can be widely used in electric vehicles and other industries. At the same time, combined with the characteristics of the disc motor, it is easy to install in the electric vehicle, and it works stably and reliably. The segmented oblique pole double-disc permanent magnet motor for electric vehicles also has a high utilization rate of permanent magnets, which can alleviate the shortage of rare earth permanent magnet materials such as NdFeB to a certain extent.

The stator of the motor body adopts a slotted back-to-back structure, and the manufacturing process is relatively mature now; the rotor has a simple structure, no windings, and high reliability; when the rotor rotates, the permanent magnet can also act as a fan, and the motor has better heat dissipation performance and reduces the heat loss of the motor Lower to increase the efficiency of the motor.

The motor adopts a double disc structure, which is very suitable for thin installation in electric vehicles. It adopts a single stator/double rotor structure. Although there is a stator core in the middle of the motor, there will be a magnetic pull between the rotor magnetic steel and the stator core. However, the motor uses a double rotor symmetrical structure. When the motor is installed correctly, there is no axial force. Magnetic pulling force improves the reliability of motor operation.

The same purpose of the stator skew can be achieved by using the rotor skew pole, that is, to weaken the harmonic component of the electromotive force and suppress the cogging torque of the motor. However, the oblique pole of the rotor can also reduce the eddy current loss of the permanent magnet, which has a gain effect on reducing the temperature of the motor; at the same time, the anti-demagnetization ability of the permanent magnet has also been greatly improved by using the oblique pole of the rotor. These are all caused by the stator chute Not available.

In the utility model, the permanent magnet adopts a segmented inclined pole method, which is different from the continuous inclined pole structure, so that it has a higher utilization rate of the permanent magnet, and not only has a stronger weakening effect on tooth harmonics and cogging torque, but also It is more conducive to reducing the production cost of the permanent magnet.

The utility model adopts a double-disk permanent magnet motor structure, and the directions of the oblique poles of the permanent magnets on the rotors on both sides are opposite, so that limited resources can be utilized to realize maximum weakening of tooth harmonics. The back EMF waveform of the segmented oblique pole double-disk permanent magnet motor for electric vehicles is more sinusoidal, and the effect of reducing cogging torque and torque ripple is more obvious.

To sum up, the utility model integrates the disc motor and the permanent magnet motor. Under the condition of ensuring the high power density and high efficiency of the motor, the tooth harmonics of the motor are reduced by using the rotor with segmented oblique poles, so that the motor The sine degree of the back EMF waveform is significantly improved, which weakens the cogging torque and torque ripple, reduces motor loss and noise, and is more suitable for the working environment of electric vehicles.

Description of drawings

Fig. 1 is a structural diagram of a segmented oblique pole double disc permanent magnet motor for an electric vehicle rotor;

Figure 2-1 and Figure 2-2 are schematic diagrams of the segmented oblique pole structure of the rotors on both sides;

Figure 3 is a schematic diagram of the plane development of the magnetic circuit of the motor;

Figure 4 is the ideal waveform of flux linkage, induced electromotive force and current in the armature winding;

In Fig. 1 there are: stator 1, rotor 2, permanent magnet 3, rotor yoke 4, armature winding 5;

In Fig. 2-1 and Fig. 2-2, there are: rotor 2, rotor yoke 4, N pole permanent magnet 6, and S pole permanent magnet 7.

Detailed ways

A rotor segmented reverse oblique polarity double disc permanent magnet motor for an electric vehicle, characterized in that the motor is composed of a stator and a rotor (2);

The stator is composed of a back-to-back slotted stator core (1) and an armature winding (5), and the armature winding (5) adopts a concentrated winding and spans across the adjacent back-to-back slotted stator core (1) in the circumferential direction. on the stator teeth;

The rotor (2) is a disk-type rotor with two symmetrically distributed on both sides of the stator. The rotor is composed of a permanent magnet (3) and a rotor yoke (4). The rotor yoke (4) is a disk The permanent magnet (3) is evenly attached to the inside of the rotor yoke (4), facing the stator, and the permanent magnets adopt an N-S corresponding arrangement structure, so that the permanent magnets are axially magnetized.

Utilizing the structural characteristics of the segmented oblique poles of the rotor poles, the tooth harmonics in the back EMF of the motor can be effectively weakened, the cogging torque and torque ripple of the motor can be effectively controlled, and the efficiency of the motor can be significantly improved.

The armature winding (5) adopts a concentrated winding, spans the adjacent stator teeth in the circumferential direction, and the armature winding (5) faces the inside of the two rotor disks, adopting a back-to-back structure.

The rotors (2) of the two-disc structure are symmetrically distributed on both sides of the back-to-back stator core (1). Both the stator and the rotor of the motor are made of wound silicon steel sheets, forming a part of the magnetic flux circuit.

The permanent magnet (3) adopts a segmented inclined pole structure, and the whole permanent magnet is evenly divided into several pieces. The segmented permanent magnets are staggered by a certain displacement to form an oblique angle between the rotor segments. The oblique angle is 0 ~40 electrical angles, the oblique angles between adjacent rotor segments are kept consistent; at the same time, the corresponding segmented permanent magnets on both sides are inclined in opposite directions.

As shown in Figure 1, the rotor segmented oblique pole double disc permanent magnet motor for electric vehicles adopts a single stator/double rotor structure, which mainly includes: stator 1, rotor 2, permanent magnet 3, rotor yoke 4, electric motor Pivot winding 5 etc. The stator core is fixed on the casing of the motor with a back-to-back structure; the armature winding 5 is distributed circumferentially on both sides of the slotted stator core, using concentrated winding; the two rotors 2 are symmetrically distributed on both sides of the stator core, coaxially flexible with the stator 1 connect.

The stator core and the rotor yoke 4 are made of coiled silicon steel sheet, which can conduct axial and circumferential magnetization. The material can be 0.5mm thick 50W470 cold-rolled non-oriented silicon steel sheet. In order to avoid magnetic flux leakage, the motor shaft should be made of non-magnetic material, so stainless steel can be used.

In Fig. 1, the number of single-side armature windings is 48, and the number of motor poles is 16.

As shown in Figure 2-1 and Figure 2-2, the permanent magnet 3 is directly surface-attached to the inner side of the rotor 2 on both sides. A certain displacement is staggered between the permanent magnets 3 to form a skew angle between rotor segments, and the skew angles between adjacent rotor segments are kept consistent.

The permanent magnets 3 on both sides are arranged circumferentially facing the stator core in the form of N poles and S poles, and the inclination directions of the segmented permanent magnets 3 on both sides are kept reversed.

In addition, in consideration of improving the air gap flux density of the motor and the thermal stability of the permanent magnet, NdFeB with higher intrinsic coercive force and remanence density is selected as the material of the permanent magnet 3 of the motor.

It should be understood that these embodiments are only used to illustrate the present utility model and are not intended to limit the scope of the present utility model. In addition, it should be understood that after reading the content taught by the utility model, those skilled in the art can make various changes or modifications to the utility model, and these equivalent forms also fall within the scope defined by the appended claims of the application.

Claims (3)

1. a kind of double-disc type permanent-magnet motor of rotor subsection reverse oblique polarity type for electric vehicle, it is characterized in that, described motor is made up of stator and rotor (2); The stator is composed of a back-to-back slotted stator core (1) and an armature winding (5), and the armature winding (5) adopts a concentrated winding and spans across the adjacent back-to-back slotted stator core (1) in the circumferential direction. on the stator teeth; The rotor (2) is a disk-type rotor with two symmetrically distributed on both sides of the stator. The rotor is composed of a permanent magnet (3) and a rotor yoke (4). The rotor yoke (4) is a disk The permanent magnet (3) is evenly attached to the inside of the rotor yoke (4), facing the stator, and the permanent magnets adopt an N-S corresponding arrangement structure, so that the permanent magnets are axially magnetized. 2. A kind of electric vehicle rotor segmented reverse oblique pole double-disk permanent magnet motor according to claim 1, characterized in that: the rotors (2) of the two-disk structure are symmetrically distributed on the back-to-back stator core ( 1) On both sides, the stator and rotor of the motor are made of wound silicon steel sheet material, which constitutes a part of the magnetic flux circuit. 3. A segmented reverse oblique pole double-disk permanent magnet motor for an electric vehicle rotor according to claim 1, characterized in that: the permanent magnet (3) adopts a segmented oblique pole structure, and the whole permanent magnet The magnet is evenly divided into several pieces, and the segmented permanent magnets are staggered by a certain displacement to form an oblique angle between the rotor segments. The oblique angle is 0 to 40 electrical degrees, and the oblique angles between adjacent rotor segments are kept consistent; At the same time, the inclination directions of the corresponding segmented permanent magnets on both sides are opposite.