Conductor Arrangement for Loss Reduction in Concentrated Winding PCB AFPM for Robotic Joints

The growing demand for compact and high-performance motors in industrial robotic joints has intensified interest in axial flux permanent magnet motors (AFPMs), which inherently offer high torque density and a thin form factor compared with conventional radial flux permanent magnet motors (RFPMs). Among various AFPM structures, printed circuit board (PCB) Stator motors have gained significant attention due to their slotless configuration, reduced cogging torque, low vibration and acoustic noise, and enhanced geometric thinness enabled by PCB-etched conductors. This study proposes a conductor arrangement strategy that mitigates back-EMF imbalance in concentrated-winding single-rotor PCB AFPM for robotic joints. Several conductor configurations are analyzed and compared through electromagnetic finite-element evaluation, and an optimized arrangement is identified that effectively improves phase EMF symmetry while maintaining structural thinness. The results provide design guidelines for high-performance PCB AFPMs suitable for next-generation robotic actuators.