| 摘要 |
A fluid bearing includes a rotor and a stator. A DC motor drives the rotator. The DC motor has (1) a multi-phase set of coils on one of the rotor and stator and (2) a multi-pole magnet on the other of the rotor and stator opposed to the coils, the number of magnet poles being an even number which is different from the number of phases and the coils and magnet poles being arranged such that, at a predetermined position of the rotor, at least one of the coils is opposed by only one magnet pole. Commutation selectively applies DC current to the at least one coil, and not to a coil opposed by more than one magnet pole, when the rotor assembly is at the predetermined position of a polarity to cause the at least one coil to repel the opposed magnet pole, creating a magnetic force urging the bearing surfaces apart. |
