Route Chart to Stabilizing Permanent Maglev Rotator

Abstract

Permanent maglev has been since long recognized to be unstable because of Earnshaw's theory, which theoretically proved that permanent maglev can not achieve stable equilibrium in static state. How about that in dynamic state, for example, about a rotator, nobody has given an answer until now actually. A permanent maglev pump and a permanent maglev turbine have been developed, by using a patented permanent magnetic bearing developed by the author. Experiments demonstrated, there is a critic speed either in the pump or in the turbine, under which the rotors in the pump and the turbine have a maximal eccentricity being possible to reach the gap between the rotor and the stator. That means the rotors have contact with the stators occasionally, and thus the rotor is not suspended. In case the rotating speed is higher than this critic speed, the rotors' eccentricity will be remarkably smaller than the gap between the rotor and the stator, that is to say the rotor is stably levitated. Further investigation exhibtes that at the critic speed a so-called gyro-effect is generated which stabilizes the rotor, just like a gyro standing over a ball, if the rotating speed is large enough it can be stable over the ball. The critic speed, essentially to be minimal stable speed of the rotor, depends on the rotating inertia of the rotor and the bearing force, the larger the inertia and the larger the force, the lower the critic speed. Conclusively, a route chart to stabilization of permanent maglev rotator has been clear: in static state, permanent maglev is unstable (Earnshaw's theory); as the rotating speed gradually increases but not up to a critic speed, the permanent maglev rotator is also unstable; in case that the speed equals or is larger than this critic speed, the permanent maglev rotator is suspended stably because of gyro-effect; the critic speed is affected by rotating inertia of the rotor and the bearing force, by larger inertia and larger bearing force, the critic speed will be smaller.