Comparison of Eddy Current Coupling Topologies for High Efficiency Mechanical Power Transmission

The article is an investigation into permanent magnet eddy current couplings for high efficiency power transmission. Through extensive simulation studies, the performance of radial- and axial-field topologies, employing squirrel cage and conducting sheets, are compared in terms of torque transmission density and efficiency of power transmission. It is shown, that although using a conducting sheet (as it is often the case) results in higher torque transmission density, employing a squirrel cage is more suitable for high efficiency power transmission. A prototype of the proposed radial-field single sided permanent magnet eddy current coupling employing a copper squirrel cage is developed and tested, and a good agreement between measurements and predictions is demonstrated.