Ω Shaped axial-flux permanent-magnet machine for direct-drive applications with constrained shaft height

This contribution investigates an original solution that can be used in the design of AFPM machines, whenever a constrained shaft height requirement penalizes a standard design. The machine is tailored for electrical traction, but the ideas that are set forth are valid for any application with constrained shaft height. Two design solutions are investigated that comply with the constrained shaft height: a standard Torus AFPM machine and an asymmetrically wound Torus machine, named “Ω AFPM” due to the shape of the stator. It is shown that the Ω AFPM machine has lower losses and a higher efficiency. FE simulations and experimental tests on a full-scale prototype confirm the validity of the proposed solution.