Five-Degree-of-Freedom Actively Suspended Axial-Gap Self-Bearing PMSM with Double Inner Stator

An axial-gap self-bearing permanent magnet synchronous motor (PMSM) controls axial force via the d-axis magnetic field, while radial force and tilting torque are regulated using the ±2-pole magnetic field components. By employing two stators, the motor achieves active control of six degrees of freedom in force and torque, enabling contactless suspension and rotation without the involvement of passive magnetic bearings. This paper presents a novel outer-rotor structure specifically designed for pump applications. The structure, control system, and the results of the levitation and rotation tests conducted on the proposed motor are presented.