Combined magnetizing type permanent magnet built-in rotor of axial magnetic field permanent magnet motor

Abstract

The invention discloses combined magnetizing permanent magnet built-in rotor of an axial magnetic field permanent magnet motor. The rotor structurally comprises two rotor discs installed on a rotatingshaft, the first rotor disc comprises a rotor iron core, permanent magnets, a rotor supporting shell and a rotor back yoke, the permanent magnets comprise the first permanent magnet and the second permanent magnet, and the rotor iron core comprises a rotor outer iron core and a rotor inner iron core; the rotor back yoke is installed on the rotor supporting shell, and the first permanent magnets and the second permanent magnets are alternately and evenly arranged on the rotor back yoke in the circumferential direction. The rotor core is fixed to the second permanent magnets arranged on the rotor back yoke together so as to keep the permanent magnets fixed in the radial direction and the axial direction; the rotor iron core, the permanent magnets, the rotor supporting shell and the rotor back yoke are fixed together to form the first rotor disc which is installed on the rotating shaft, and then the first rotor disc is connected with the second rotor disc through the rotating shaft to fix the position of the second rotor disc in the axial direction to form a double-rotor structure. The permanent magnet rotor is good in magnetism gathering effect, high in air gap flux density and large in reluctance torque.

Description

technical field [0001] The invention relates to the technical field of axial flux permanent magnet motors, in particular to an axial magnetic flux permanent magnet motor combined magnetization type permanent magnet built-in rotor. Background technique [0002] Axial field PM motors, also known as disc PM motors, are an attractive alternative to cylindrical radial flux PM motors due to their pancake shape, compact construction, and high power density. Built-in type and surface-mounted type are two main rotor magnetic circuit structures, and in the axial field permanent magnet motor, the permanent magnet surface-mounted type structure is generally used. The main disadvantages of the surface-mounted structure are: the eddy current loss on the surface of the permanent magnet of the rotor is serious, the permanent magnet is difficult to fix, the structural strength of the rotor is not high, the reluctance torque cannot be used, and the magnetic density of the air gap is low, espe...

AI Technical Summary

Problems solved by technology

The main disadvantages of the surface-mounted structure are: the eddy current loss on the surface of the permanent magnet of the rotor is serious, the permanent magnet is difficult to fix, the structural strength of the rotor is not high, the reluctance torque cannot be used, and the magnetic density of the air gap is low, especially when the motor operates at high power and high speed. In the case of operation, the permanent magnet will also be subject to a large centrifugal force and the electromagnetic attraction of the stator, and the installation and protection of the permanent magnet has become a technical difficulty

[0003] The patent "An Axial Magnetic Field Permanent Magnet Ironless Motor with Magnetic Concentration Function" adopts the method of setting permanent magnetic strips to reduce magnetic flux leakage in the gap between two adjacent opposite-sex sectoral main magnetic poles of surface-mounted permanent magnets. The magnetic concentration effect is achieved. The patent "a hub motor based on the axial magnetic field of the rotor with a magnetic concentration structure" achieves the magnetic concentration effect by setting the first sector magnet and the second sector magnet whose magnetization directions are perpendicular to each other. However, these two methods The permanent magnet surface mount type can not avoid the disadvantages of the surface mount type structure

The patented "Stator Coreless Halbach Permanent Magnet Array Axial Flux Motor" uses Halbach permanent magnet array to achieve high air gap flux density, but the amount of permanent magnets is large, and the magnetization direction of each permanent magnet under each pole is different , which increases the difficulty of processing and installation of permanent magnets, and still uses a surface-mounted structure

[0004] To sum up, almost all the rotor structures of the axial field permanent magnet motors that can achieve the magnetic concentration effect at present adopt the permanent magnet surface-mounted structure. It is difficult to avoid the defects of the permanent magnet surface-mounted rotor structure, and there are still permanent magnets. Large eddy current loss, difficult installation and protection of permanent magnets, low structural strength, inability to utilize reluctance torque, low air gap flux density, high cost, etc.

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