Pump

Claim 2

A pump comprising: a rotor in a housing having a primary inlet and a primary outlet and crescent-shaped pumping cavities; said rotor being journaled for rotation in bearings and having slots therein; means for rotating said rotor; blades in said rotor slots movable outwardly by centrifugal force and pressure forces in said cavities to pump liquid, which is likely to include solid contaminants, from said primary inlet to said primary outlet; a cylindrical self-cleaning wash-flow filter; means for conveying the contaminated liquid from said primary outlet and along the axis of said wash flow filter; a secondary pumping section defined at least in part by said slots and the inner portion of said blades; a secondary inlet and a secondary outlet inwardly of the outer periphery of said rotor and communicating with said secondary pumping section; means for filtering a relatively small portion of the contaminated liquid through said wash flow filter to provide a source of clean liquid; and means for supplying said clean liquid to said secondary inlet, the clean liquid thereby being pumped to said secondary outlet and in so doing cleaning the primary pumping section handling the contaminated liquid.

Claim 3

A dual function lobe pump having a primary pumping section and a secondary pumping section, said pump comprising: a housing having an inlet connected to a source of a liquid, which is likely to include solid contaminants, and an outlet for said liquid; a cavity in said housing; a rotor having journals arranged for rotation in said cavity with its periphery defining therewith at least one crescent-shaped pumping chamber; means for rotating said rotor; inlet and outlet ports communicating respectively with sAid inlet and outlet and said pumping chamber; radial slots in said rotor; blades in said slots movable outwardly by centrifugal and pressure forces to pump the contaminated liquid through said pumping chamber and from said inlet to said outlet; a secondary pumping chamber defined by the inner end of a blade and a slot; a secondary inlet port and a secondary outlet port; filter means for deriving clean liquid from the pumped contaminated liquid; said secondary inlet port communicating with said filter means and said secondary pumping chamber at one position of said rotor; said secondary outlet port communicating with said secondary pumping chamber at another position of said rotor; whereby upon rotation of said rotor, clean liquid is pumped from said filter means through said secondary inlet to and out said secondary outlet.

Claim 4

A dual function lobe pump having a primary pumping section and a secondary pumping section, said pump comprising: a housing having an inlet connected to a source of a liquid, which is likely to include solid contaminants, and an outlet for said liquid; a cavity in said housing; a rotor having journals arranged for rotation in said cavity with its periphery defining therewith at least one crescent-shaped pumping chamber; means for rotating said rotor; inlet and outlet ports communicating respectively with sAid inlet and outlet and said pumping chamber; radial slots in said rotor; blades in said slots movable outwardly by centrifugal and pressure forces to pump the contaminated liquid through said pumping chamber and from said inlet to said outlet; a secondary pumping chamber defined by the inner end of a blade and a slot; a secondary inlet port and a secondary outlet port; filter means for deriving clean liquid from the pumped contaminated liquid; said secondary inlet port communicating with said filter means and said secondary pumping chamber at one position of said rotor; said secondary outlet port communicating with said secondary pumping chamber at another position of said rotor; whereby upon rotation of said rotor, clean liquid is pumped from said filter means through said secondary inlet to and out said secondary outlet.

Claim 5

A pump as recited in claim 2 further comprising means communicating said secondary outlet with said journals for the passage of liquid for lubrication thereof.

Claim 6

A pump as recited in claim 3, further comprising bearing surfaces in said housing for said rotor and means communicating said secondary outlet with said bearing surfaces for the lubrication thereof.