20130043744 | METHOD OF CONSTRUCTING CORE WITH TAPERED POLE PIECES AND LOW-LOSS ELECTRICAL ROTATING MACHINE WITH SAID CORE - An electrical rotating machine having a stator or a rotor with a core that includes a plurality of tapered pole pieces is a low loss electrical machine that results in improvements such as higher output power, higher torque and higher efficiency than a machine that does not have tapered pole pieces. The stator or the rotor with tapered pole pieces may be applied to a power train in automobiles, power tools, and various appliances. A method of constructing the core includes winding an iron-based amorphous magnetic alloy ribbon to form a cylinder-shaped core, then heating, impregnating with resin, and machining the cylinder-shaped core to form a plurality of tapered pole pieces being separated in an alternating manner by a plurality of slots. The cores having an outside diameter in a range of 50 mm-1200 mm, a tapered angle in a range of 10°-45°, and a slot depth in a range of 10 mm-210 mm are advantageous. | 02-21-2013 |