An Integrated Gear Drive Unit with Flux-Focusing Magnetic Gear

This paper presents a novel integrated gear drive unit (IGDU), which integrates a high torque density flux-focusing magnetic gear with a V-shaped interior permanent magnet (IPM) motor into a compact structure. The proposed configuration enables direct torque amplification and efficient low-speed, high-torque operation, addressing the inherent torque limitations of conventional electric motors. Critical design parameters, including pole-pair selection, modulation ring dimensions, and stator slot openings, are optimized to enhance torque performance and minimize cogging torque. Finite element analysis (FEA) verifies a maximum torque output of 43.7 Nm. A prototype of the proposed IGDU was fabricated, and experimental validation confirms the effectiveness of the design, with a good match between the measured back-EMF and the simulated one. The results highlight the potential of the proposed machine for compact, high-performance applications such as electric vehicles and industrial drives.