Analysis of the magnetic field created by permanent magnet rings in permanent magnet bearings

This paper presents a simple mathematical model to determine the three dimensional (3D) magnetic field components in Permanent Magnet (PM) bearings made of ring magnets with axial, radial and perpendicular polarizations. MATLAB codes are written to evaluate the magnetic field components using Coulombian model and simple vector approach. In addition, the effect of axial, radial and angular displacements (five degrees of freedom) of the rotor magnet ring on the magnetic field created by the ring magnets in PM bearings is presented. Finally, the effect of movement of the outer ring magnet on the magnetic field created by two rings in the air gap is discussed.