US Patent 7701095 Permanent-magnet generator and method of cooling

The invention is a generator and cooling mechanism. The generator includes a rotor comprising a shaft with a skewed alignment of magnets on a ring, a stator of toothed laminations with coils wound around the teeth, and a housing with cooling chambers. The housing has annular subchambers arranged successively along the length of the generator in such a way that cooling fluid must flow to the opposite side of the generator to pass into the next chamber. Because the housing is highly heat conductive, this structure of annular subchambers increases the uniformity of the fluid temperature.