Investigation of a New Ironless-Stator Self-Bearing Axial Flux Permanent Magnet Motor

In this paper, a new type of self-bearing axial flux permanent magnet (SBAFPM) motor with ironless stator is proposed. The torque windings and the suspension windings are integrated into a cohesive whole with the same pole number for both torque and radial force generation. The fundamental structure and the working principle of the presented ironless-stator SBAFPM motor with ironless stator are illustrated. The control method and the implementation for the integrated windings system to produce force and torque independently are presented, as well as an FEA model for calculating the achievable drive torque and suspension force. Results indicate that the bearing force and the drive torque depend linearly on the respective current. The presented ironless-stator SBAFPM motor is free from tradeoff between force and torque, which will simplify the control of the torque and the levitation force.