Permanent Maglev Centrifugal Pump Stabilized by Gyro-effect

The authors have studled on the permanent maglev centrifugal pump just using passive magnetic bearings for working permanently. A radially driven centrifugal pump was constructed, which had a rotor and a stator. The rotor consisted of driven magnets and an impeller ; the stator had a motor coil and a pump housing. Two passive magnetic bearings were devised to resist the attractive force between the motor coil iron core and rotor driven magnets.Bench testing with saline demonstraed that the rotor can be suspended in the stator if the rotating speed of the pump was larger than 3,250rpm and the flow rate was larger than 1 lit/min. High speed is a precondition to realize a so-called gyro-effect which stabilizes the passive maglev rotor and high flow rate is an indication of a good hydraulic property of the pump.