Study on Slot Number of Stator for Development of Small Diameter Radial Type Self-Bearing Motor

Abstract

Magnetic levitation technology is applied for durability enhancement of ventricular assist device. We have developed a pediatric magnetic levitated ventricular assist device using a radial type self-bearing motor. The radial type self-bearing motor consist of a stator and a rotor which has 4 permanent magnet on the inner surface of the rotor. The minus two-pole algorithm is adopted to levitate and rotate the rotor. Radial position of the rotor is controlled actively, and axial position of it is passively stable within the thin rotor structure. In this paper, two-dimensional magnetic field analysis of the self-bearing motor using 5 slots stator, 6 slots stator and 7 slots stator were performed, and an optimal slot number of stator for development of small diameter radial type self-bearing motor was examined. As a result, 5 slots stator is good slot number for the radial type self-bearing motor which has 4-pole rotor.