A One-degree-of-freedom Controlled Magnetic Bearing for Compact Centrifugal Pumps

We propose a compact one-degree-of-freedom controlled magnetic bearing for centrifugal pumps, such as implantable ventricular assist devices. The magnetic bearing passively supports radial and tilt motion of the rotor by a combination of attraction and repulsion of permanent magnets. A pair of electromagnets controls axial motion of the rotor and stabilizes the levitation of the rotor. An experimental rotor, which is 50 mm in diameter, 17 mm in height and 0.11 kg in weight, could levitate stably and rotate at a rotational speed of up to 2 400 rpm without contact in air.