Low-suction head pumps

Claim 1

AN IMPROVED PUMPING SYSTEM FOR AN ABSORPTION REFRIGERATION SYSTEM COMPRISING IN COMBINATION, A HERMETICALLY SEALED HOUSING DISPOSED TO RECEIVE SPENT ABSORBENT; A CENTRIFUGAL PUMP DISPOSED IN SAID HERMETICALLY SEALED HOUSING SAID PUMP INCLUDING A CENTRAL INLET AND A PERIHERAL OUTLET SECTION; A PUMP IMPELLER SHAFT, BEARING FOR SAID SHAFT A ROTARY IMPELLER SUBSTANTIALLY COAXIAL WITH SAID INLET MOUNTED ON SAID SHAFT; MEANS FOR PREVENTING ROTATION OF LIQUID IN THE INLET, INCLUDING AN INLET SECTION HAVING NONCONVERGING WALLS IMMEDIATELY ADJACENT TO THE IMPELLER; AND MEANS FOR PREVENTING TURBULENCE IN THE INLET SECTION, INCLUDING IMPELLER BLADES ARRANGED TO IMPART IMPART AND FRICTIONAL FORCES TO THE LIQUID IN THE PUMP SUBSTANTIALLY ENTIRELY IN DIRECTIONS TO MOVE THE LIQUID IN RADIALLY OUTWARD AND TANGENTIAL DIRECTIONS; AN ELECTRIC DRIVE MOTOR DISPOSED IN THE HERMETICALLY SEALED HOUSING, SAID ELECTRIC MOTOR INCLUDING A STATOR AND A ROTOR MOUNTED ON SAID PUMP IMPELLER SHAFT; AND MEANS IN THE HERMETICALLY SEALED HOUSING FOR COOLING AND LUBRICATING THE BEARING OF THE SHAFT BY A PORTION OF A PUMPED STREAM INCLUDING A SETTLING CHAMBER COMMUNICATING WITH THE PERIPHERAL OUTLET SECTION OF THE PUMP, A COOLING COIL IN THE STATOR OF THE DRIVE MOTOR A LINE ARRANGED TO WITHDRAW A PART OF THE PUMPED STREAM AND TO INTRODUCE THE SAME INTO SAID COOLING COIL AND TO SAID BEARING TO BE LUBRICATED AND COOLED.