Abstract
Bearingless canned motor pumps, which employ 5-axis active electromagnetic control, have been developed. In this paper, two types of 5-axis active control type bearingless canned motor pump are introduced and explained about the difference of each structure. One is a conventional structure which was investigated in the past research, the other is a novel structure which was newly proposed. One of the most important difference between these two types is the machine size. To realize miniaturization, the structure of suspension stator core was optimized to insert radial gap sensors into slots. In addition, suspension rotor cores were also used as gap sensor targets. Thus, the area of the radial gap sensors and the gap sensor targets which was arranged to the both ends of the electromagnetic machine could be deleted. Furthermore, a passive thrust magnetic bearing was effectively inserted in the dead space of an active radial magnetic bearing arranged at the buttocks side. As a result, the whole machine size could be miniaturized. Although the machine size was miniaturized, the experimental results demonstrated that the proposed novel structure has enough output power and suspension force. In addition, the proposed structure could reduce the flow loss, because the rotor length was decreased through the miniaturization. Accordingly, whole input power also could be reduced. In this paper, these advantages will be shown by the pump experiments with water.
