Fluid displacement pump

An internal gear fluid displacement pump. The fluid displacement pump includes an outer gear having internal teeth disposed about an inner surface thereof, an annular element constituting the rotor of an electric motor, this element having an internal diameter substantially equivalent to an external diameter of the outer gear, the annular motor rotor affixed to the outer gear, an inner gear having external teeth disposed about an outer surface thereof for meshing with the internal teeth of the outer gear, the inner gear having fewer teeth than the outer gear, the internal teeth of the outer gear and the external teeth of the inner gear defining a plurality of expansion and pumping chambers when the outer gear is rotatably driven by the electric motor rotor, the bearing surface operable to support the outer gear during rotation thereof, a motor stator element electromagnetically engaging the annular motor rotor element for rotationally driving the outer gear, the motor stator having a soft ferromagnetic core and coil winding assembly and a non-magnetic housing disposed between the motor stator coil windings and the annular magnet, the outer diameter of the annular motor rotor element and the inner diameter of the non-magnetic housing constituting a journal and bearing system which is lubricated by the pumped fluid and is effective to maintain a fixed electromagnetic circuit gap between the inner diameter of the motor stator and the outer diameter of the annular motor rotor element during the operation of the pump.