Performance investigation of a centrifugal pump with a 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. The passive stiffness 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 fluid force. The rotor vibration is significantly smaller than the fluid gaps in the pump casing. In addition, significant torque ripple of the consequent-pole bearingless motor has no influence on the suspension performance. The experimental results demonstrate that the proposed consequent-pole bearingless motor is feasible and effective for a centrifugal pump.