Patent ID: 7362012

Claim:
An armature assembly including a plurality of windings; a base portion; a plurality of teeth extending from the base portion to form a stack and about which the windings can be positioned, and wherein the plurality of teeth are spaced apart from each other at a predetermined pitch, t t , to define slot openings at ends of and between adjacent teeth, and including a first end tooth positioned at one end of the stack in a direction of motion and a second end tooth positioned at another end of the stack in the direction of motion; and wherein the first and second end teeth are formed to have a wedge shape, and further wherein a length of the stack in any cross-section in the direction of motion is selected so that the stack covers an area of a plurality of magnets in a field assembly corresponding to a non-integer number of magnets which area is substantially the same over a range of motion and further wherein the first and second end teeth each have a portion which extends outwardly beyond the base portion in the direction of motion.