Patent ID: 6537049
Filing Date: 2003-03-25
Classification: F04C

Abstract:
A screw pump comprising a first shaft spaced from and parallel to a second shaft mounted in a pump body, a first rotor mounted on the first shaft and a second rotor mounted on the second shaft, each rotor having formed on an outer surface at least one helical vane or thread, the helical vanes or threads intermeshing together so that rotary movement of the shafts will cause a fluid to be pumped from an inlet towards an outlet of the pump, a first bearing arrangement associated with the first shaft and a second bearing arrangement associated with the second shaft, the first and second bearing arrangements being positioned in cavities within the first and second rotors, respectively, which are sealed at their ends closest to the pump inlet, wherein a thermal shield is provided between each of the bearing arrangements and internal surfaces of the cavities, and a substantially sealed annular gap is defined between the thermal shield and each bearing arrangement thereby allowing the heat shield to operate at a higher temperature than each bearing arrangement.