| 摘要 |
<p>PURPOSE:To allow the bearing to work with its full function even under power failure by providing the rotor with capability of starting only when the amount of suppliable power by an emergency power supply means, which is sensed prior to start of the rotor, corresponds to the amount needed to decelerate the rotor to a lower speed in the event of power failure. CONSTITUTION:When power supply to a charger 12 is started and the time T1 set on a timer relay 14 has passed, the (a) contact 14a' is put in closed condition and a motor 3 is now capable to be started. In case power supply to the circuits is shut, the (a) contact 14a' is opened and power supply to said motor 3 stops. However, the (a) contact 17a is closed in the time T2 set on a timer relay 18, and a battery supplies power to each electro-magnetic bearing. Here the time T1 is a period necessary to charge the battery fully, and the time T2 is a period to allow the rotor to speed down sufficiently when the power is shut.</p> |
