Accurate Prediction and Analysis of Electromagnetic Fields and Forces in Flux-Focusing Eddy Current Coupling With Double Slotted Conductor Rotors

Permanent magnet eddy current couplings are promising devices for torque and speed transmission without any mechanical contact. In this paper, flux-focusing permanent magnet eddy current couplings with double slotted conductor rotors are proposed and investigated. Given the drawback of the accurate 3-D finite element method, the purpose of this paper lies to establish an accurate and fast analytical model to evaluate the electromagnetic field and torque of such devices with non-homogeneous boundary conditions. Thus, based on the 2-D sub-domain method, the magnetic vector potential in each sub-domain is formulated and solved by the separation of variables method. Taking into account the eddy current effects and slotting effects, the closed-form expressions of magnetic field, induced current, electromagnetic force, and torque for such devices are obtained. Finally, the 3-D finite element method is employed to validate the analytical results.