Patent ID: 7795772

Claim:
A motor comprising: a stator including a magnetic stator core and a stator winding; a rotor including a rotor core and a plurality of permanent magnets arranged to form north(N) and south (S) poles of the rotor; a plurality of low permeability layers arranged in sequential rows with each of the low permeability layers being positioned at a different radial distance from a center of the rotor core such that at least one of the magnets is positioned along a path that extends between two directly adjacent low permeability layers and at a different radial distance from the center of the rotor than the directly adjacent low permeability layers, and each of the low permeability layers has a lower magnetic permeability than the rotor core and extends between respective ones of the N and S poles in a direction generally parallel to the magnetic flux paths of the permanent magnets, such that the permanent magnets and the low permeability layers are arranged to obstruct the magnetic flux between the N and S poles to provide a forward salient pole characteristic; and a current control device configured to produce a current whose phase is shifted such that the magnetic flux of the permanent magnets intensifies.