Applications of Permanent Maglev Bearing in Heart Pumps and Turbine Machine

Abstract

Earnshaw's theorem (1839) stated that no stationary object made of magnets in a fixed configuration can be held in stable equilibrium by any combination of static magnetic or gravitational forces. What will happen by a moving body like a rotating passive magnetic levitator? Nobody has given an answer until now. The author applied a self-made passive magnetic bearing to radial pump and turbine machine and found that if the rotating speed could be higher than a critical value, 3250 rpm for a pump and 1800 rpm for a turbine, the rotors would be disaffiliated from stators and keep the rotation stable. It seems that the fast rotating levitator has a so-called "Gyroeffect" which makes the passive maglev rotator stable. These results have extended Earnshaw's theorem from static to dynamic equilibrium. In static state or by a speed lower than critical value, the passive maglev rotator cannot keep rotation stable; if the rotating speed is higher than critical speed, the passive magnetic levitator will have Gyroeffect and thereby stabilize its rotation.