Quantitative considerations to self-centering magnetic suspensions with permanent magnets

Center containment and simultaneous support of rotating bodies by forces between two permanent magnets has become a technical reality due to high-coercive force magnets. The Self-Centering principle is described and experimental results are reported as examples for the advantages of the new arrangement over conventional magnetic bearings. Performance tests of prototype units are described concerning the damping conditions and the centering functions. Centering forces and supporting forces can be adjusted independently to meet changing requirements by positioning of the axle by an end bearing or by ac-forces. The actual forces measured for barium ferrite units are compared with the forces measured for samarium cobalt units. Typical values show the samarium cobalt units to be up to 25 times stronger (by weight) and up to 40 times better (per unit volume) than barium ferrite bearings, forces were measured in excess of 100 times the weight of the magnets. Analytical, computerized studies for the basic forces have been made for optimization and the design for combinations of many units for high stiffness requirements.