High Integrated Methodology and Evaluation for Switched-Reluctance Type Bearingless Motors with Five Degree of Freedom Magnetic Levitation

To make bearingless motors more competitive in military and industrial applications, the volume and cost issues for the system need to be taken into account. In this paper, a series of highly integrated five degree of freedom (DOF) bearingless switched reluctance motors (BSRMs) without rare earth materials are proposed. The features of the novel topologies include the conical pole, the conical disk, the conical cylinder, and the thrust cylinder. The magnetization current is applied to generate the radial and axial fluxes based on these topologies. The axial levitation can be implemented by the two units without axial levitation windings. The two rotors are assembled on the shaft in parallel with 15
$^{\circ }$
shifted for the torque compensation, and the four-DOF radial levitation can be implemented as well. According to the simulation and experiment results, the characteristics of the proposed topologies are evaluated. These novel topologies have a greater axial bearing capacity, and the capacities of the torque and the five-DOF levitation are guaranteed. In addition, the proposed topologies have broad application prospects in high-speed rotation and high-integration fields.