The Passive Characteristics of a Repulsion Magnetic Bearing
Abstract:
Magnetic suspension systems can meet the requirements for spacecraft momentum wheel bearings. The main aim of the work described in this Report was to investigate the effects of interleaving soft iron spacer rings of various thicknesses between the magnetic rings of a repulsion type magnetic bearing. An optimum thickness of iron ring was found which produced a maximum increase in radial stiffness over the stiffness obtained with iron spacers. The magnetic inhomogeneity of the magnets was measured and found to have a small effect on the radial stiffness. Theory predicts that a single repulsion bearing will be cross-axially stable if the ratio of its length to diameter exceeds 3. This value was confirmed within the uncertainty of the experiment. The external magnetic fields from representative bearing assemblies were measured. Author