| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a vacuum pump having superior rotation startability. <P>SOLUTION: The vacuum pump includes a magnetic bearing 3 for carrying out the magnetic levitation of a rotor 4, a bearing control unit 8 for controlling the levitation position of the rotor 4 by controlling the excitation current of the magnetic bearing 3, a motor rotor fixed to the rotor 4 and having a permanent magnet, a motor stator for rotation-driving the motor rotor, and a main control unit 9 which makes the rotor 4 eccentric from the bearing center position to the prescribed radial direction by the magnetic bearing 3, generates the fixed magnetic field facing the prescribed direction by the motor stator, and adjusts the angle in the rotational direction of the rotor 4. The main control unit 9 returns the rotor 4 with its angle in the rotational direction adjusted to the bearing center position from the offset state in the prescribed radial direction, and the motor control unit 7 generates the rotational magnetic field for rotating the rotor 4 returned to the bearing center position by the motor stator. <P>COPYRIGHT: (C)2013,JPO&INPIT |
