Additively Manufactured Winding Design for Thermal Improvement of an Oil-Cooled Axial Flux Permanent Magnet Machine

This article proposes a new additively manufactured winding with integrated heat sinks to improve thermal performance of an oil-cooled yokeless and segmented armature (YASA) axial flux permanent magnet machines. The heat sinks featuring pin-fin structure are integrated to the two sides and top of the winding to increase the heat transfer area and convective heat transfer coefficient, thus improving the thermal performance. Computational fluid dynamics is employed to evaluate the thermal performance of the proposed winding, which is further compared with that of the state-of-the-art rectangular winding. Besides, the influence of pin spacing in streamwise direction, tilt angle, flow rate and resistances on the thermal performance and pressure drops of the proposed winding are investigated. Finally, prototypes of the proposed winding and the counterpart rectangular winding are manufactured to verify the numerical analyses. The experimental results show that the winding temperature of the proposed winding can be reduced by 27.6 °C compared with that of rectangular winding.