What are the advantages and design considerations of axial flux machines?

Axial flux machines have disc-shaped rotors with flux paths parallel to the shaft. Advantages include: high power density (especially for flat form factors), good cooling of stator windings, easy integration with wheels (in-wheel motors), and modular multi-disc construction for power scaling. Design considerations include: large thrust bearing requirements, electromagnetic axial forces, manufacturing of concentrated windings, and thermal management of rotor PMs. Topologies include single-rotor, dual-rotor (YASA type), and dual-stator. Growing application in EVs, aviation, and wind generators.