Patent ID: 7701106

Claim:
A downhole electric motor having at least three phases and comprising: a permanent magnet rotor; and a stator comprising: a laminated stator core having closed slots formed therein; and phase windings, wherein: the phase windings extend through the closed slots, each phase winding in incorporates a plurality of coils each coil extending through a respective pair of closed slots and surrounding a respective portion of the stator core between said pair of closed slots, adjacent coils of different phases extend through opposite parts of a respective one of said pair of closed slots, said adjacent coils are separated by a gap through which cooling fluid may be pumped to cool the coils, and by virtue of the conforming shape of said respective one of the closed slots, the coils are held in thermal contact with a thermally conductive projection integral with and projecting directly from the stator core and extending at least part of the way across said respective one of the closed slots.