Induction bearings

A self stabilizing homopolar induction bearing withintegrated touch down bearings has been developed forhigh-speed applications like flywheels, small gas turbines andcompact vacuum cleaners. Stability is achieved without any control electronics thanksto stabilizing eddy currents induced by permanent magnets. Eddycurrent losses are reduced to a minimum using a homopolardesign with ring magnets instead of multipole or halbacharrays. The bearing currents and forces are simulated using steadystate 3D-FEM analysis, which is enabled thanks to theimplemented Minkowskij transform. From these results ananalytical model has been developed, and the results arecompared. Efforts are made to develop a qualitative understanding ofthe bearing physics. Results are converted into usefulrotordynamic data that is easily understood by machineengineers. Finally some experiences from the first experimental testruns at 90.000 RPM are discussed. Keywords:Magnetic bearing, eddy current, inductionbearing, eddy current bearing, high speed, homopolar, gasturbine, flywheelNR 2014080