Magnetically floating actuator having angular positioning function

Abstract

An actuator is provided with a rotor formed to include teeth at a predetermined pitch and a rotation control coil is wound on each of plural pole pieces formed on a core member opposing the rotor, the coils forming first, second, third and fourth magnetic poles. The rotor is rotatatively driven and angularly positioned by attracting forces between the magnetic poles and the teeth of the rotor. Magnetic flotation coils are wound on the base portion of the magnetic member to form magnetic flotation poles. The rotor is floated magnetically by attracting forces between the magnetic flotation poles and the teeth of the rotor. In an embodiment, the rotor is provided with grooves crossing the teeth to form the teeth into a mesh-like configuration. The mesh-like teeth cooperate with the magnetic poles to provide a holding force in the axial direction, so that a function equivalent to that of a thrust bearing may be performed.

Dependencies are inferred from the claim text.