A Novel OrbiTran Magnetically Geared Rotating Electrical Machine

This paper presents a novel electrical machine topology with a built-in magnetic gear, combining concepts from cycloidal magnetic gears and rolling-rotor electrical machines. It enables electromechanical conversion in both motor and generator modes. To overcome the complex rotation typically associated with cycloidal gears, the high-speed and low-speed rotors are mechanically decoupled. The high-speed rotor performs translational motion along a small orbit, which inspired the name "OrbiTran". A 2D FEM model with a gear ratio of 60 was developed, demonstrating a torque density of 114 kN·m/m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> under relatively low thermal load on the stator windings, which typically corresponds to natural convection cooling. It was also demonstrated that the proposed machine can continuously operate at maximum torque density with negligible torque ripples. Since the component of the machine responsible for electromechanical conversion relies on reluctance torque, and PMs are naturally shielded from armature magnetic fields, the proposed device is expected to exhibit a high degree of fault tolerance. Despite its many advantages, proposed topology still inherits significant radial imbalances from the cycloidal magnetic gear, and the rolling-rotor machine it is based on.