Patent ID: 7230361

Claim:
A high efficiency, high power density permanent magnet electro-magnetic device comprising: (a) at least one stator assembly including a magnetic core formed from a low-loss soft-magnetic material and having a plurality of slots wound with stator windings adapted to be connected to at least one electrical phase; and (b) at least one magnetic field assembly including a plurality of rotor poles, the magnetic field assembly comprising a plurality of permanent magnets and being arranged and disposed for magnetic interaction with the at least one stator assembly, wherein a torque density of the device is at least about 2.5 N-m/kg and a loss density of the device is at most about 0.2 W/cm 2 , the values of the torque density and the loss density being measured during continuous operation of the device as a generator connected to a resistive load and at a rotational speed providing electrical output at a frequency of at least about 500 Hz.