Design and Construction of a Fault-Tolerant Yokeless and Segmented Armature Axial Flux Motor for Aerospace Actuator Applications

This paper presents a fault tolerant, dual three-phase yokeless and segmented armature (YASA) type axial flux permanent magnet (PM) motor, specifically developed for aerospace actuator applications. The motor features a 12-slot, 10-pole rotor configuration with segmented soft magnetic composite stator cores and concentrated tooth windings, offering optimized performance for robust aerospace operation. Response surface optimization has been conducted for the proposed machine, considering loss and torque responses in relation to the machine's geometric parameters. Various fault scenarios were simulated using 3D finite element analysis, while transient structural simulations examine the effect of magnetic forces on rotating components of the machine. The investigation indicates that the magnetic forces acting on the rotor disks in the event of short circuits induce abrupt force fluctuations in the machine's bearings causing vibration. Furthermore, the manufacturing challenges of the proposed YASA AFM have been addressed, as the machine necessitates a structural holder for the segmented SMC stator, fabricated using metal additive manufacturing technology.