Shaft rotation driving apparatus for machine tool

摘要

A shaft rotation driving apparatus for a machine tool having a main spindle for rotating a tool or a workpiece, comprises: a magnetic anisotropic rotor formed integral with the main spindle itself or with a rotary sleeve itself fitted to the main spindle; a stator disposed coaxially along an outer circumference of the magnetic anisotropic rotor; a field winding wound around the stator, for magnetizing the rotor in a predetermined direction; and an armature winding wound around the stator, for providing a rotative force to the rotor.