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An eccentric harmonic magnetic gear (EHMG) is better suited for situations requiring larger transmission ratios than magnetic-field-modulated magnetic gears. In the meantime, to increase the torque density even further, a new structure for EHMGs is presented in this paper. The stator's permanent magnets (PMs) are irregularly distributed, while the rotor's PMs are applied to a fan-shaped structure. Moreover, a Halbach array is adopted in both the rotor and the stator. A two-dimensional finite element (FE) model of the proposed EHMG is developed, and the flux density distribution and torque of the EHMG are calculated and verified via FE analysis. When compared to a conventional EHMG, the presented model's torque increases from 38.04 Nm to 50.41 Nm. In addition, for the sake of avoiding the oscillation and noise caused by resonance, a modal analysis of the proposed model is conducted and the consequences show that it has better antivibration properties. Finally, a prototype is made, a test bench is established, and the correctness and effectiveness of the proposed model are verified. [ABSTRACT FROM AUTHOR]

As a typical representative of the stator permanent magnet (PM) machines, the flux reversal machines (FRMs) have a simple structure, high availability of PMs, and high efficiency, making them suitable for direct drive applications. However, the PMs of the FRMs are mounted on the surface of the stator tooth, and its equivalent length of air gap is relatively large, which limits the torque increase. To improve the torque density, a novel FRM with auxiliary teeth is proposed in this paper. Half of the stator teeth are replaced by auxiliary teeth without PMs to reduce magnetic flux leakage, the number of PMs on each stator tooth is also changed. To improve the torque, the genetic algorithm is used to optimize the key design parameters to determine the optimal parameters of the machine. Finally, a finite element model is established to verify the analysis results. Compared with the conventional FRM, the torque of the proposed FRM is increased by 25.1%, the torque ripple is reduced by 24.1%, and the consumption of PMs is reduced by 24.1%. Therefore, the proposed FRM has a broader application prospect. [ABSTRACT FROM AUTHOR]