Dynamic properties of superconducting magnetic bearings

The potential use of YBa/sub 2/Cu/sub 3/O/sub 7/ as an active component in a magnetic bearing is being investigated. Although the load bearing capacity is high and increases with the square of the magnetic field trapped, the stiffness is low. Both the stiffness and the levitation height are a function of the loading history of the bearing. The authors have been investigating the effects of dynamic loading such as single large excursions from steady state loads and cyclically applied loads such as vibrations. Since a superconducting bearing has little inherent damping, cyclic loads applied at or near its natural frequency can have catastrophic effects. The information being gathered by the authors will be used to enable these effects to be mitigated in the bearing design process.