Patent ID: 7064469

Claim:
Core for an axial flow electrical machine comprising a substantially ring shaped coreback and a plurality of teeth, wherein said coreback includes: a plurality of stacked, ring shaped sheets of soft magnetic material and a barrier of electrical resistance arranged between two adjacent sheets of soft magnetic material for reducing effects of eddy currents, wherein each sheet of soft magnetic material in at least a subset of said plurality of stacked, ring shaped sheets of soft magnetic material includes a plurality of first tooth engaging portions and a plurality of second tooth engaging portions, a first tooth engaging portion and a second tooth engaging portion being arranged to at least partially define a tooth opening, and wherein each sheet of soft magnetic material in at least a subset of said plurality of stacked, ring shaped sheets of soft magnetic material further includes a plurality of first outer closing portions and a plurality of second outer closing portions, a first outer closing portion and a second outer closing portion being arranged to face each other between an outer perimeter of said sheet of soft magnetic material and said tooth opening, and wherein said plurality of teeth are made of soft magnetic material and each tooth of said plurality of teeth is arranged in a tooth opening and is extending from said coreback in a direction essentially parallel with an axial direction of said coreback.