| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic bearing in which touch-down can be prevented upon power interruption without using a large and high capacity battery. SOLUTION: Upon interruption of a power supply 21, a rotary shaft sustains inertial rotation to supply each part of a magnetic bearing 3 with a current i1 generated by electromotive force induced in a motor 2 thus sustaining magnetic levitation of the rotary shaft. Electromotive force being induced in the motor 2 decreases as them revolution decreases and when it reaches a limit level where electromagnets 6, 7 can not levitate a rotator 1, a battery 23 begins to power supply to each part of the magnetic bearing 3 through a diode 24. Consequently, the rotary shaft 1 can be stopped without causing touch-down. Since touch-down is prevented through combination of the electromotive force induced in the motor 2 and the battery 23 power in case of power interruption, battery capacity can be reduced. |
