Plastic structure multi-disc axial flux PM motor

Abstract

High efficiency at full load as well as at partial load and high torque density are the challenging characteristics required by the propulsion system for a solar aircraft. The proposed solution is a multi-disc axial flux PM motor with a mechanical structure made of plastic materials: (a) the multi-disc geometry allows high torque density by increasing the number of air-gap surfaces; (b) the PMs and the (almost) ironless magnetic circuit, cutting the no load losses, allow very high efficiency over the complete working range; (c) the motor structure made of plastic materials, with high thermal and mechanical characteristics, allows further increases in the torque density. The paper presents the motor design and performances.