Abstract
A compact maglev motor has been developed for use in implantable ventricular assist devices. The maglev motor consists of a homopolar type radial magnetic bearing (MB) and a radial flux permanent magnet synchronous motor (PMSM). A rotor is magnetically suspended with the inner MB and is driven by the outer PMSM. The maglev motor has an external diameter of 60 mm and a height of 20 mm. In this research, torque and energy efficiency characteristics of the developed PMSM were evaluated. In addition, magnetic levitation and rotation performance was then investigated. Maximum rotational torque of the PMSM is 26 mNm. Maximum energy efficiency of the PMSM is 58% at a rotating speed of 5000 rpm and rotating torque of 11 mNm. Power consumption of the PMSM is less than 8 W at required toque for circulatory support. Oscillation amplitude of the levitated impeller in radial direction is around 0.06 mm, except maximum oscillation amplitude of 0.17 mm at the resonance rotating speed of 3800 rpm. Power consumption of the MB is less than 2 W at an operational speed range of the VAD. The developed maglev motor indicated the better rotation performance and the sufficient magnetic levitation stability.
