An Investigation of the Characteristics of Electromagnetic Bearings Using the Finite Element Method

Abstract

The load capacity of EMBs with a restricted air gap is usually small in comparison with that of traditional ball bearings. One possible way to overcome this limitation is to increase the operation field strength of EMBs; however, this approach unavoidably involves nonlinear characteristics of EMBs. This paper investigates the nonlinear behavior of two commonly used types of EMBs by using the finite element method, in which the nonlinear relation of the B-H curve, the flux leakage, and the fringing effect are taken into account. The behavior of the EMBs under different bias currents and gap lengths is investigated, as are the effects of geometric parameters on the bearing characteristics. The results of the paper provide a useful guide for designing EMBs when using their nonlinear characteristics.