Estimating equation of the radial type self-bearing motor's the passive stability

Abstract

An implantable ventricular assist device requires that to have a high durability and efficiency, to flow blood without non-sliding, and miniaturizing the device. Therefore, we have developed a ventricular assist device using a radial type self-bearing motor. In the self-bearing motor, the radial position of the rotor is controlled actively, and the axial position of the rotor is passively stable within the thin rotor structure. In this paper, the estimating equation of the restoring force corresponding to the self-bearing motor's the passive stability in the axial direction was developed in order to reduce the designing time and elucidate the magnetic suspension characteristic. The estimating equation has the sufficient calculation accuracy that can be used for the prior design of the magnetic field analysis. The estimating equation has elucidated the interaction of the permanent magnet field and the magnetic field of rotation.