Evaluation of Magnetic Suspension Characteristics and Levitation Performance of a Centrifugal Blood Pump Using Radial Type Self-Bearing Motor

Magnetic levitation technology is applied for durability enhancement of artificial hearts. A centrifugal blood pump using a self-bearing motor was previously developed for use as an implantable artificial heart. Rotors of three types which are different of magnetic suspension characteristics were fabricated. The magnetic suspension characteristics, the levitation and the pump performances of the Maglev pump were examined. If the negative spring force in the radial direction was weak, the restoring force in the axial direction and the restoring torque of the inclination were not always weak. It is possible to improve the motor performance by increasing the flux density of permanent magnet, even if the air gap is increased. It revealed that the levitation performance does not influence the pump performance. And then, it is possible to improve the levitation performance by reducing the negative spring force and improving the passive stability ability.