Development of highly efficient hybrid magnetic bearing and application to ultra-low temperature fluid pump

Highly efficient hybrid type magnetic bearing is proposed in this paper. It is intended to apply the proposed magnetic bearing to ultra low temperature fluid pump. Traditional low temperature pump is supported by a ceramic ball bearing which is damaged by the low temperature liquid. Non-contact support is highly requested. However, the standard electro-magnet type magnetic bearing consumes high electric power causing heat to the liquid. This paper proposes highly efficient hybrid type radial magnetic bearing which can operate with very low power consumption. Also the pump is canned by FRP pipe which has thick wall to separate the stator from the liquid. The designed magnetic bearing has 3 mm wide air gap. The fabricated magnetic bearing shows good dynamic properties with high force factor.