A Hybrid Coaxial Magnetic Gear Using Flux-Focusing Halbach Permanent Magnet Arrangement

The interest in developing magnetic gears (MGs) has been considerably increased in recent years due to the numerous advantages such as high torque density, low maintenance and overload protection. In this paper, a new MG that integrates flux-focusing and Halbach configurations is proposed. The special design of the radially magnetized permanent magnets (PMs) at both edges of the inner rotor improves the magnetic field distribution and enables the proposed MG to be designed with a high torque density. Parameter sweep analysis is used to maximize the torque density of the proposed flux-focusing Halbach coaxial MG (FFH-CMG), and reduce the volume of PM material used in the design. Finally, the electromagnetic performance of the proposed FFH-CMG is investigated using both 2D and 3D finite element analysis (FEA). The results show that the proposed FFH-CMG can achieve the largest torque density when compared with its counterparts and maintain a low torque ripple.