Development of a Compact Centrifugal Pump With a Two-Axis Actively Positioned Consequent-Pole Bearingless Motor

A novel centrifugal pump has been developed that employs a bearingless motor with two-axis radial active positioning control. The structure of this motor is an extension of a hybrid of consequent-pole and homopolar-type bearingless motors. Based on 3-D finite-element-method analysis, the influence of the permanent-magnet dimension and motor current on magnetic suspension characteristics has been investigated. The passive stiffness of this motor has been enhanced. The test pump was fabricated and found to provide a maximum pump output of 1 W with a flow rate of 4 L/min against a head pressure of water of 1.5 m. An impeller with a shroud contributes to a significant reduction in axial impeller movement caused by axial thrust. The rotor vibration is significantly smaller than the fluid gaps in the pump casing. The experimental results demonstrate that the proposed consequent-pole bearingless motor is feasible and effective for use with a centrifugal pump.