Double-permanent magnet outer-rotor permanent magnet biased radial magnetic bearing

Abstract

The invention relates a double-permanent magnet outer-rotor permanent magnet biased radial magnetic bearing comprising outer magnetic conductive rings, outer permanent magnets, stator cores, excitation windings, inner magnetic conductive rings, inner permanent magnets and rotor cores, wherein four magnetic poles consist of each stator core, eight magnetic poles of the left end and the right end of the magnetic bearing consist of two stator cores, and magnetic poles in the positive and the negative directions of an X axis and a Y axis respectively consist of the eight magnetic poles; each stator magnetic pole is wound with the excitation winding; the rotor cores are positioned outside the stator cores; the outer magnetic conductive rings are positioned outside the rotor cores; the outer permanent magnets are positioned among the outer magnetic conductive rings; the outer magnetic conductive rings are connected with the rotor cores; certain gaps are retained on the inner surfaces of the rotor cores and the outer surfaces of the stator cores to form air gaps; and the permanent magnets are positioned among the inner magnetic conductive rings. The invention solves the problem of large remanence moment of the traditional permanent magnet biased outer-rotor radial magnetic bearing for space.

Description

technical field [0001] The invention relates to a non-contact magnetic suspension bearing, in particular to a dual permanent magnet external rotor permanent magnet offset radial magnetic bearing for compensation of residual magnetic moment, which can be used as a non-contact support for rotating parts such as magnetic suspension flywheels for space use, reducing its own Remanence Magnetic interference with external components. Background technique [0002] Magnetic suspension bearings are divided into pure electromagnetic type and hybrid magnetic suspension bearing with permanent magnetic bias and electromagnetic control. The former uses large current and high power consumption, and the hybrid magnetic suspension bearing with permanent magnetic bias and electromagnetic control uses permanent magnets instead of pure electromagnetic magnetic bearings. The bias current in the bearing generates a bias magnetic field, the magnetic field generated by the permanent magnet bears the...

AI Technical Summary

Problems solved by technology

[0003] The analysis shows that the magnetic sources that generate the residual magnetic moment in the maglev flywheel mainly include permanent magnets, soft magnetic materials and energized coils, and the magnetic moment generated by the permanent magnets is the main magnetic source of the residual magnetic moment of the entire maglev flywheel. The existing authorized patent The magnetic levitation flywheel structure proposed by ZL200710098750.7 provides a magnetic levitation flywheel with an outer rotor with short axial length, which adopts the outer rotor radial magnetic bearing structure of ZL200510011270.3, because the permanent magnet of the motor in the flywheel system is a radial Alternate and symmetrical magnetization, the axial magnetic bearings are used in pairs to make the permanent magnets symmetrical, so the permanent magnetic remanence moment of the two can be approximated to 0, only the radial magnetic bearing uses a permanent magnet circle due to the traditional structure The ring generates a bias magnetic field and is an asymmetric permanent magnet structure, so it will generate a large residual magnetic moment, which will cause magnetic interference to other components

There are few existing methods for compensating the residual magnetic moment. The main method is to measure the residual magnetic moment through experiments, and to perform magnetic compensation through the magnetic torque device in the flywheel according to the magnetic conditions in the track. This method is very complicated to implement. Another method is to compensate by adding permanent magnets. This method is still based on experimental tests, and the compensation of external permanent magnets is performed according to the measured results. The size of the permanent magnets added by this method has no rules to follow. Moreover, the external permanent magnet increases the volume of the flywheel and other devices, and the external permanent magnet brings unpredictable loss to the magnetically conductive rotating part of the flywheel and other devices at high speed, which affects the stability of the magnetic performance of the whole machine.

In view of the above reasons, the existing radial magnetic bearings have defects such as large residual magnetic moment in the axial direction and the existing compensation method is very complicated and will increase the volume of the device.

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