Radial Position Active Control of Double Stator Axial Gap Self-Bearing Motor for Paediatric VAD

A novel axial gap double stator self-bearing motor which can control five-degrees of freedom (5-DOF) of rotor postures have been developed for paediatric ventricular assist device (VAD). The motor has a top stator, a bottom stator and a levitated rotor driven as a synchronous permanent magnet motor. The rotor is axially suspended between the stators which have an identical structure. A double stator mechanism enhances a higher torque production and realizes radial position active control. This paper proposes a concept of radial position active control and magnetic suspension ability of developed selfbearing motor. The rotor is successfully levitated and rotated up to 6400 rpm without any physical contact with 5-DOF active control in air. The radial oscillation amplitudes are actively suppressed with the proposed radial position control concept. The developed 5-DOF controlled self-bearing motor which is suitably miniature as an actuator for paediatric VAD indicates sufficient capability of the magnetic levitation and non-contact rotation.