Patent ID: 7044289

Claim:
Screw conveyor for the transport of flowable substances and/or lumps of material, comprising: a rotatable first screw provided with helical windings and arranged in a housing with an inlet opening and an outlet opening, said housing comprising an inlet chamber and a pumping chamber between said inlet and outlet openings, a second screw provided with helical windings and arranged for rotation in an opposite direction of the first screw, said first and second screws inside the pumping chamber providing a positive displacement pumping function by close-fitting engagement between flights and grooves of the first and second screws and between the flights of the first and second screws and a wall of the pumping chamber, two transport screws in the inlet chamber mounted on common axles with the first and second screws, wherein a transition between the first and second screws and the two transport screws is positioned such that at least one half winding of the first and second screws extends out of the pumping chamber and into the inlet chamber, and wherein the first and second screws have a constant pitch, and wherein downstream ends of the first and second screws are mounted in bearings, said bearings being fixed relative to one another by a first rod connection between the bearings forming a floating connection.