Stiffness and Damping of an Eddy Current Magnetic Bearing

Abstract

The perturbation method, aided by symbolic computation software, is employed to solve Maxwell’s equations to obtain theoretical predictions of forces and stiffness and damping coefficients for a simplified eddy current magnetic bearing. The results show that this kind of bearing has low stiffness and extremely low damping compared to conventional bearings. In fact, the damping is probably negative in most cases. In addition, the cross-coupled stiffness is relatively high, further contributing to rotor-dynamic problems. Despite these drawbacks, if advanced high temperature superconducting materials become practical, eddy current magnetic bearings may be useful in many applications.