A Novel S-Shape Offset Type of a Modulated Ferromagnetic Pole Piece Design for a Pseudo Direct Drive Motor

This paper proposes a novel Pseudo Direct Drive (PDD) motor design. An S-Shape Offset Type (SOT) of a modulated ferromagnetic pole piece ring based on a self-adhesive steel sheet was introduced to improve the fragile structure and flux leakage problems of the traditional PDDs. The stress and flux distribution comparison between the traditional PDD and the proposed design were simulated by three-dimensional finite element analysis (FEA). It was found that the SOT pole piece ring could not only maintain the same flux leakage but also enhance the structural strength. Moreover, the torque behavior and efficiency were investigated, and a prototype was manufactured to prove its feasibility.