A Novel Low-Cost Endplate Using Same Rotor Core Silicon Steel Sheet for Interior Permanent Magnet Motors in Domestic Applications

This paper proposes a low-cost endplate for interior permanent magnet (IPM) motors in domestic applications. The novelty of the proposed solution lies in utilizing the same rotor core silicon steel sheet as the endplate to eliminate the cost of dedicated rotor endplates. However, since the proposed endplates and rotor core are the same, the magnets can move axially without the limitation of the endplates. To address this issue, the proposed endplates are rotated at a certain mechanical angle concerning the rotor core. In such a solution, the endplates cannot be mounted to the rotor core using rivets since the original rivet holes between them no longer coincide. Thus, additional rivet holes are designed so that some rivet holes between them can coincide after the rotation of the proposed endplates. Besides, due to the high permeability of the endplates, flux barriers in the endplates are studied to mitigate leakage flux at the rotor end. Specifically, the design considerations of the proposed endplates are investigated, including the rotation angle, rivet holes, and flux barriers. Two IPM motors adopting the proposed endplates at different rotation angles are developed and compared with the conventional counterpart by using three-dimensional (3D) finite element analysis (FEA). It shows that the overall performance of the IPM motor adopting the proposed endplates at a proper rotation angle is comparable to the conventional design. Experimental results verify the effectiveness of the IPM motor with the proposed low-cost endplates.