Patent ID: 7294948

Claim:
A rotor-stator structure for electrodynamic machines comprising: cylindrical magnets having cylindrical surfaces arranged axially on an axis of rotation, said cylindrical magnets including at least two cylindrical magnets being positioned so that the directions of polarization of said at least two cylindrical magnets are in substantially opposite directions; and field pole members arranged coaxially to said axis and having flux interaction surfaces formed at the ends of said field pole members adjacent to portions of said cylindrical surfaces that confront said flux interaction surfaces, said flux interaction surfaces and said portions of said cylindrical surfaces defining air gaps, said flux interaction surfaces being configured to magnetically couple said field pole members to said cylindrical magnets, wherein said flux interaction surfaces are contoured to maintain a substantially uniform cross-section for each of said air gaps, wherein said directions of polarization are in one or more planes that are substantially perpendicular to said axis of rotation, wherein at least one of said field pole members is a substantially straight field pole member.