Bearings for motor pump units

Claim 1

A MOTOR PUMP UNIT COMPRISING A STATOR, A ROTOR MOUNTED WITHIN SAID STATOR, A CYLINDRICAL CAN POSITIONED INTERMEDIATE SAID ROTOR AND SAID STATOR, A SHAFT COUPLED TO SAID ROTOR, AN IMPELLER MOUNTED ON SAID SHAFT FOR ROTATION THEREWITH, A CASING SURROUNDING SAID IMPELLER AND HAVING A HYDRAULIC INLET AND OUTLET, A BEARING HOUSING CONNECTED TO SAID CASING AND SURROUNDING SAID SHAFT INTERMEDIATE SAID ROTOR AND SAID IMPELLER, BEARINGS MOUNTED IN SAID HOUSING FOR SUPPORTING SAID SHAFT, THE RADIALLY INNER SURFACE OF SAID BEARING DEFINING A PLURALITY OF AXIALLY SPACED SETS OF CIRCUMFERENTIALLY ARRANGED CAVITIES AND ANNULAR GROOVES INTERMEDIATE SAID SETS OF SAID CAVITIES, MEANS CONNECTING THE OUTLET OF SAID CASING TO SAID CAVITIES FOR RECEIVING A PORTION OF THE FLUID BEING PUMPED, SAID MEANS INCLUDING SEPARATE PASSAGES IN SAID BEARING HOUSING EACH OF WHICH IS CONNECTED TO A DIFFERENT ONE OF SAID SETS OF CAVITIES, SAID BEARINGS HAVING AXIALLY EXTENDING CONDUITS RADIALLY SPACED FROM SAID INNER SURFACE AND COMMUNICATING WITH THE ANNULAR GROOVES IN SAID BEARINGS FOR CONDUCTING FLUID AWAY FROM SAID CAVITIES, SAID IMPELLER HAVING APERTURES THEREIN AND COMMUNICATING WITH SAID CONDUITS FOR RETURNING FLUID TO THE INLET SIDE OF THE IMPELLER.