Electric vehicle permanent magnet motor composite rotor and preparation method thereof

Abstract

The invention discloses an electric vehicle permanent magnet motor composite rotor, which is characterized in that the composite rotor is composed of a reluctance section rotor and a permanent magnetsection rotor, and specifically comprises a hollow rotor iron core and a central rotating shaft, the center of the rotor iron core is provided with a central rotating shaft hole through which the central rotating shaft passes, and the central rotating shaft hole tightly sleeves the motor central rotating shaft; the rotor core comprises an outer wall and an inner wall, the end surface of the rotorcore is provided with N (even number) groups of magnetic steel grooves into which permanent magnet monomers are inserted; two permanent magnet monomers are symmetrically embedded in each group of magnetic steel grooves, wherein the permanent magnet monomers with the same polarity are inserted into the magnetic steel grooves in the same group, and the permanent magnet monomers with opposite polarities are inserted into the magnetic steel grooves in the adjacent group. The invention also discloses a preparation method of the electric vehicle permanent magnet motor composite rotor. By synchronously improving the structure and the preparation process, the material cost is reduced, the torque density and other properties are kept at a high level, the torque density and the power density of themotor are high, and the irreversible demagnetization resistance is high.

Description

technical field [0001] The invention relates to the technical field of permanent magnet motors for new energy electric vehicles, in particular to a composite rotor of permanent magnet motors for electric vehicles and a preparation method thereof. Background technique [0002] Motors are devices that convert mechanical energy to electrical energy, including motors and generators, and are widely used in many fields such as industry, agriculture, aerospace, transportation, communications, computers, scientific research, office equipment, household appliances, medical equipment, and environmental protection machinery. In response to the shortage of fuel resources and the damage to the natural environment caused by vehicle exhaust emissions, many countries in the world are actively working to develop various new energy vehicles; as a new energy, pollution-free and zero-emission vehicle, the motor has become the core power drive components, and can also be used as a generator to r...

AI Technical Summary

Problems solved by technology

[0005] One is the AC motor, which has low efficiency, large volume and weight, and poor speed response

[0006] The second is the permanent magnet motor. The permanent magnet synchronous motor also has its own shortcomings. The permanent magnet material on the rotor will have magnetic degradation under the conditions of high temperature, vibration and overcurrent. Therefore, under relatively complicated working conditions, the motor is easy to Damage occurs; and the price of permanent magnet materials is high, so the cost of the entire motor and its control system is high

[0007] The third is the switched reluctance motor. At present, judging from the mature motor technology, the switched reluctance motor seems to be more in line with the needs of electric vehicles in terms of various technical characteristics, but its vibration and noise problems are particularly important for electric vehicles, especially small ones. Passenger vehicles cannot withstand it, so it has not yet been popularized, and it is only in the testing stage on cargo transport vehicles

[0009] However, there are still some defects in the existing technology. The amount of rare earth used in the rare earth permanent magnet brushless DC motor is relatively large, and the price of rare earth materials is expensive. Usually, only the raw material cost of the rare earth permanent magnet material accounts for the total cost of the entire motor material. more than half of

Moreover, the price of rare earth permanent magnet materials fluctuates greatly, which is not conducive to the long-term and stable cost control of manufacturers

In order to reduce the material cost of the motor, if the amount of rare earth permanent magnets is directly reduced, the torque density of the motor will be difficult to reach the level of the existing permanent magnet brushless DC motor, which will reduce the performance of the motor

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