Development of an External Rotor V-Shape Permanent Magnet Machine for E-Bike Application

This paper proposes the design and development of an external rotor permanent magnet in-wheel motor for an electric bicycle application. The proposed machine utilizes V-shape magnets embedded in the external rotor to achieve enhanced magnetic flux concentration and, hence, high torque and power output. Detailed design principles and performance characteristics of the proposed machine are comprehensively evaluated with finite element analysis. Various design concerns are further investigated to ensure machine rigidity and operational safety. Finally, this paper validates the design concept with a prototype machine. High torque and high power output are achieved and the experimental results confirm the design simulations with good agreement.