Design and Analysis of A Novel AFPM with Opposite-Rotation Dual Rotors

This paper proposes a novel opposite-rotation dual-rotor axial flux permanent-magnet machine (ORDR-AFPM) for underwater vehicle counter-rotation propeller propulsion system. The structure of the machine mainly consists of dual identical surface-mounted PM rotors, dual sets of concentrated windings and single stator sandwiched in between the dual rotors. The dual rotors operate independently like dual conventional machines but toward opposite directions. For the purpose of exploring the interaction between the dual rotors and verify the feasibility of the machine, the flux distribution in the dual air gaps is analyzed by magnetic equivalent circuit (MEC). Meanwhile, finite-element method (FEM) is also used to confirm the validity of the theoretical analysis. During the process of machine design, the axial magnetic force is analyzed by using Maxwell stress tensor and the main design parameters of the machine get optimized.