Novel Lorentz Force-Type Magnetic Bearing With Flux Congregating Rings for Magnetically Suspended Gyrowheel

摘要

The Lorentz force-type magnetic bearing (LFMB) depends on the high uniformity of magnetic flux density to output high precision torque for the magnetically suspended gyrowheel (MSGW) integrating attitude measurement and control. In this article, to investigate the reasons of poor uniformity of magnetic flux density, the magnetic field distribution of the conventional LFMB is analyzed. Using flux congregating rings, a novel LFMB is proposed and its magnetic field in the radial and circumferential directions is studied. The magnetic flux density uniformity is improved effectively without the reduction of the magnetic field. The force mathematical model of the novel LFMB is established by magnetic field division and equivalent magnetic circuit method. Its suspension force and torque are calculated by the 3-D finite-element method (3-D FEM). The error between theoretical and FEM simulation results is less than 10%. The performance of the conventional and novel LFMBs is comparatively analyzed by FEM. The force linearity between force and rotor deflection angle was improved effectively in the novel LFMB, which could improve the measurement accuracy of an attitude angular rate of the gyro carrier for the MSGW.