Axial flow pump

Claim 1

A PUMP COMPRISING A FIXED TUBULAR HOUSING, TWO HOLLOW, LONGITUDINALLY SPACED END CAPS WITHIN AND RIGIDLY CONNECTED TO SAID HOUSING, ONE AT THE INLET AND THE OTHER AT THE OUTLET END OF THE PUMP, A FIXED AXLE EXTENDING FROM ONE CAP TOWARD THE OTHER, AN INDUCTION MOTOR STATOR FIXEDLY CARRIED BY SAID AXLE BETWEEN SAID CAPS, A TUBULAR WALL COAXIAL WITH AXLE AND DISPOSED BETWEEN SAID CAPS, A PAIR OF CAP PLATES ON OPPOSITE SIDES OF THE STATOR CLOSING THE ENDS OF SAID TUBULAR WALL AND RESPECTIVELY CLOSING THE HOLLOWS OF THE CAPS A ROTATIONAL BEARING BETWEEN ONE CAP AND THE CAP PLATE AT THAT END, AN ANTIFRICTION BEARING BETWEEN THE LATTER CAP PLATE AND THE AXLE, AN ANTI-FRICTION BEARING BETWEEN THE OTHER CAP PLATE AND THE AXLE, MEANS RIGIDLY CONNECTING SAID TUBULAR WALL AND THE CAP PLATES TO FORM A STATOR-ENCLOSING ASSEMBLY ROTATIONAL ON THE AXLE AND HAVING AN INTERIOR SPACE, A MOTOR ROTOR CARRIED BY SAID TUBULAR WALL IN ELECTRICAL RELATIONSHIP TO THE MENTIONED STATOR, AN ANNULAR PASSAGE BEING DEFINED BETWEEN THE TUBULAR HOUSING AND THE TUBULAR WALL, AND COOPERATING PUMP COMPONENTS DISPOSED IN SAID PASSAGE, ONE CARRIED BY THE ROTATIONAL TUBULAR WALL AND THE OTHER BY THE FIXED TUBULAR PUMP HOUSING, THE HOLLOWS OF BOTH CAPS BEING VENTED TO THE INLET END OF THE PUMP TO PROVIDE EQUAL AND OPPOSITE PRESSURE IN SAID HOLLOWS AGAINST THE CAP CLOSURE PLATES TO BALANCE THE PRESSURE DIFFERENTIAL BETWEEN THE DISCHARGE AND SUCTION ENDS OF THE PUMP AS IMPOSED ON THE MOTOR ROTOR.