Patent ID: 7564157

Claim:
An A.C. synchronous interior permanent magnet machine, comprising concentrated windings; a plurality of poles each provided on a secondary side with at least one slot, with a material thickness h 1 of said secondary side between an air-gap surface of said at least one slot and a secondary side surface, with a material thickness h 2 between an inner lying surface of the at least one slot and an inner surface, and with a thickness d of said secondary side, wherein the ratio h 1 /d lies within a range 0.05-0.35, wherein the poles on the secondary side are configured so that a section of iron between the poles on the secondary side is wider than a section of iron between said slots within the pole and is configured such that the section of iron is driven into saturation during normal operation thus increasing an inductance of a path along an axis of the machine without a need to remove the iron to create an air uocket into a flux path in order to increase an inductance.