Electric motor with plural cooling paths through the shaft

Claim 1

IN A MOTOR-PUMP ASSEMBLY, A MOTOR HOUSING DEFINING A MOTOR CHAMBER AND A PUMP HOUSING DEFINING AN IMPELLER CHAMBER, A MOTOR INCLUDING A STATOR AND A ROTOR DISPOSED IN SAID MOTOR CHAMBER, A ROTATABLE SHAFT EXTENDING BETWEEN AND BEING DISPOSED IN SAID CHAMBERS, SAID ROTOR BEING SECURED TO SAID SHAFT FOR ROTATION THEREWITH, AN IMPELLER IN SAID IMPELLER CHAMBER SECURED TO SAID SHAFT FOR ROTATION THEREWITH, SAID PUMP HOUSING HAVING INLET MEANS COMMUNICATING WITH THE SUCTION SIDE OF SAID IMPELLER AND OUTLET MEANS COMMUNICATING WITH THE HIGH PRESSURE SIDE OF SAID IMPELLER FOR DIRECTING LIQUID FROM SAID INLET MEANS THROUGH SAID IMPELLER TO SAID OUTLET MEANS, AND MEANS FOR COOLING SAID SHAFT AND ADJACENT MOTOR CHAMBER AREA WITH LIQUID FROM SAID PUMP HOUSING, THE LAST MENTIONED MEANS COMPRISING A FIRST PASSAGE IN SAID SHAFT EXTENDING GENERALLY LENGTHWISE THEREOF, BOTH ENDS OF SAID FIRST PASSAGE BEING CLOSED, ELONGATED MEANS MOUNTED IN SAID FIRST PASSAGE AND DEFINING A SECOND PASSAGE EXTENDING GENERALLY LENGTHWISE OF SAID SHAFT, SAID ELONGATED MEANS BEING CONNECTED TO THE SHAFT-ROTOR-IMPELLER ASSEMBLY FOR ROTATION THEREWITH, SAID SECOND PASSAGE AT ONE END THEREOF COMMUNICATING WITH SAID FIRST PASSAGE, ORIFICE MEANS IN SAID SHAFT COMMUNICATING ONE OF SAID PASSAGES WITH THE HIGH PRESSURE SIDE OF SAID IMPELLER FOR INTRODUCING PRESSURIZED LIQUID FROM SAID PUMP HOUSING INTO SAID ONE PASSAGE, AND OTHER ORIFICE MEANS COMMUNICATING THE OTHER PASSAGE WITH THE SUCTION SIDE OF SAID IMPELLER FOR EGRESS OF THE PRESSURIZED LIQUID FROM SAID OTHER PASSAGE, WHEREBY LIQUID FROM SAID PUMP HOUSING WILL CIRCULATE THROUGH SAID PASSAGES UPON ROTATION OF SAID SHAFT-ROTOR-IMPELLER ASSEMBLY, FOR COOLING SAID SHAFT AND ADJACENT MOTOR CHAMBER AREA, AND THUS COOLING SAID MOTOR.