Abstract: The present invention provides a variable reluctance actuator system and method that can be adapted for simultaneous rotation and translation of a moving element by applying a normal-direction magnetic flux on the moving element. In a beneficial example arrangement, the moving element includes a swing arm that carries a cutting tool at a set radius from an axis of rotation so as to produce a rotary fast tool servo that provides a tool motion in a direction substantially parallel to the surface-normal of a workpiece at the point of contact between the cutting tool and workpiece. An actuator rotates a swing arm such that a cutting tool moves toward and away from a mounted rotating workpiece in a controlled manner in order to machine the workpiece. Position sensors provide rotation and displacement information for a swing arm to a control system.

Abstract: An a.c. electrical machine includes a plurality of first elements spaced from each other; a plurality of second elements spaced from each other and interstitially disposed with the first elements; a plurality of electrical windings on each of the first elements providing a current flow in a first direction; and a return for completing a magnetic flux path in a second direction perpendicular to the first direction on successive first elements and through the second elements for generating a force in a third mutually perpendicular direction between the first and second elements.

Abstract: An a.c. electrical machine includes a plurality of first elements spaced from each other; a plurality of second elements spaced from each other and interstitially disposed with the first elements; a plurality of electrical windings on each of the first elements providing a current flow in a first direction; and a return for completing a magnetic flux path in a second direction perpendicular to the first direction on successive first elements and through the second elements for generating a force in a third mutually perpendicular direction between the first and second elements.