1-Dof Bearing Arrangement with Passive Radial Bearings and Highly Efficient Integrated Electrodynamic Dampers, EDD

This paper briefly describes a novel 1-DOF bearing arrangement with integrated passive electrodynamic dampers. A general problem with passive magnetic bearings is that sufficient damping in the radial direction is difficult to provide, without using additional rubber bushings or squeeze film dampers. Electrodynamic damping schemes are sometimes proposed, but they tend to have either weak or nonlinear properties, or they contribute to additional bearing instability in terms of negative stiffness. The proposed bearing arrangement is inherently stable in terms of positive stiffness in radial direction. For dynamic stability it comprehends short circuit coils with geometries that allow for both damping coefficient and cut-off frequency to be chosen at will. A discussion on alternative coil winding schemes and possible active control is done, and finally some preliminary test results from the first prototype are presented, indicating both a stable and a linear behavior.