Patent ID: 8564228

Claim:
An electric machine including: a first part, being a stator or rotor/runner, including a first segment with a first number of mutually spaced poles; a second part, being a rotor/runner or stator, including a second segment with a second number of mutually spaced poles arranged to transduce between electrical and mechanical energy by magnetic interaction with the poles of the first segment, the second segment having substantially the same length as the first segment; and permanent magnets in the poles of the first or second parts, wherein the second number differs from the first number by one to substantially reduce the magnetic interference forces in the direction of motion, wherein gap depths in gaps between the poles of each part are sufficiently deep to substantially attenuate magnetic interactions between a body of each part and the poles of the other part, thereby reducing magnetic interference forces between the first part and the second part, and wherein each part is symmetrical in a direction transverse a direction of motion between the first part and the second part and transverse a depth of the parts for substantially balancing magnetic forces acting perpendicular to the direction of motion.