Computational characterization of the magnetic force and stability of passive magnetic bearings with diametrical magnetization

Abstract

This paper examines the behavior of the axial component of magnetic force ($F_z$) and magnetic rigidity ($k_z$) in diametrically magnetized passive magnetic bearing configurations (PMBs). Numerical simulations of computational electromagnetism (CEM) based on the finite element method were performed to evaluate the behavior of $F_z$ and $k_z $ in various bearing configurations. First, an analytical expression of the magnetic field of a diametrically magnetized ring is presented, with the aim of identifying the parameters that determine the behavior of that field and hence the magnetic force. Additionally, $F_z$ and $k_z$ are analyzed based on the axial displacement of the internal magnets of systems formed by one or two diametrically magnetized bearings. Finally, the magnetic force and rigidity of three sets of two PMBs are compared. The first set is magnetized radially, the second set is magnetized axially, and the third set is magnetized diametrically.