磁気勾配浮上機構における円筒状鉄ロータの動的挙動(機械力学,計測,自動制御)

抄録

The magnetic gradient levitation is also called as a mixed-μ levitation and composed of at least three materials with different magnetic permeability, namely iron, air and superconductor. This levitation method enables to levitate the iron rotor keeping no contact with any parts. Utilization to flywheel is expected considering of the reduction of rotational loss and cost-down of rotor. We constructed the levitation experimental device which arranged the circular superconducting coils, the cylindrical magnetic shielding plate made of NbTi superconductor, and the cylindrical iron rotor farther inside in series. We tried the rotational tests of the iron rotor. As a result, the non-contact levitation keeping rotation was realized, but the unstable whirling phenomena appeared at the high rotational speed over 2100min^<-1>. We analyzed this behavior by the aid of finite element magnetic analysis and revealed the mechanism of this instability.