Analysis of specific load capacity of radial hybrid magnetic bearing

This paper proposes a method based on vector calculation of flux density to evaluate thespecific load capacity (SLC) of radial hybrid magnetic bearing (RHMB). The vector sum of the fluxdensities generated by the permanent magnet and the control current is calculated in this method, andthen the functional expression of the SLC is built up via the flux densities. The influence of outer rotordiameter, fraction of circumferential rotor surface covered by poles and the length of the air gap areanalyzed. It turns out that the SLC decreases with the maximum force of the bearing, and increasesfirst and then decreases with the increase of pole area and length of the air gap. The maximumattainable SLC for RHMB of all sizes does not vary substantially from 23:1. The results of theanalysis provide basis for the prediction of volume and mass for the RHMB in application.