Rotor of electromotor

Abstract

The invention discloses a rotor of an electromotor. The rotor of the electromotor comprises a rotor core and multiple sets of permanent magnets, wherein the multiple sets of permanent magnets are buried in the rotor core. Each set of permanent magnets comprise multiple permanent magnet layers which are mutually arranged in the radial direction of the rotor core at intervals. The permanent magnet layer, closest to the surface of the outer circumference of the rotor core, of the multiple permanent magnet layers is a ferrite permanent magnet layer. The other permanent magnet layers of the multiple permanent magnet layers are rare earth neodymium ferrum boron permanent magnet layers. By the adoption of the rotor of the electromotor, the reluctance torque and the electromagnetic torque of the electromotor can be increased, efficiency of the electromotor is increased without increasing cost of the electromotor, and the problems of noise and vibration deterioration of the electromotor can not be caused. Besides, operating reliability of the electromotor can also be guaranteed, and the electromotor can also be stably operated under high frequency.

Description

technical field [0001] The invention relates to the technical field of motors, in particular to a rotor of a motor. Background technique [0002] At present, in the rotor of a motor made of high magnetic permeability materials, in order to improve the output torque and efficiency of the motor, there are generally multiple sets of permanent magnets embedded in the rotor core, and each set of permanent magnets includes radially arranged With 2 or 3 permanent magnet layers, this type of rotor has the characteristics of making full use of the reluctance torque to improve the output torque and efficiency of the motor. [0003] However, in the prior art, such as figure 1 The rotor of a motor shown, although the reluctance torque of the motor has increased, and Pn*ψa*Iq representing the electromagnetic torque, due to the inherent characteristics of the low remanence Br in the ferrite material, it is different from the motor stator The interlinked magnetic flux ψa is low, and the ...

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Problems solved by technology

[0003] However, in the prior art, such as figure 1 The rotor of a motor shown, although the reluctance torque of the motor has increased, and Pn*ψa*Iq representing the electromagnetic torque, due to the inherent characteristics of the low remanence Br in the ferrite material, it is different from the motor stator The interlinked magnetic flux ψa is low, and the electromagnetic torque is also low, so the total torque T does not increase much, and the efficiency of the motor is not ideal. In addition, the coercive force in the ferrite material is low, and the demagnetization performance of the motor Deterioration, when the motor is subjected to abnormal conditions, the motor is prone to failure, and its reliability cannot be guaranteed

[0004] In addition, in the prior art, such as figure 2 The rotor of another motor shown is made of high-cost rare earth materials, and its remanence Br is also high, and the magnetic flux ψa interlinked with the motor stator is relatively high, so that the total electromagnetic torque and the efficiency of the motor can also reach ideal state, but the cost of the motor is greatly increased, and the problem of vibration and noise deterioration of the motor will also occur. In addition, when the motor needs to be operated at a high frequency, due to the high remanence Br of the rare earth material, the back electromotive force of the motor increases with the speed The corresponding increase in proportion to the rise of the external power supply makes it impossible for the external power supply to inject current into the motor, so that the motor cannot run stably at high frequency

[0005] To sum up, the rotor of the existing electric motor will either lead to an unsatisfactory increase in the efficiency of the electric motor and low reliability; or it will cause the cost of the electric motor to increase greatly, the vibration and noise of the electric motor will deteriorate, and the electric motor cannot be stabilized at high frequency running problems, therefore, the rotor of the existing motor needs to be improved

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