Silent variable delivery hydraulic pump

Claim 1

IN A HYDRAULIC POWER TRANSMISSION MACHINE OF THE TYPE HAVING AN INLET, AN OUTLET, A ROTATABLE BARREL WITH A PLURALITY OF EQUALLY SPACED CYLINDERS ARRANGED PARALLEL TO THE AXIS OF ROTATION OF SAID BARREL, A PLURALITY OF PISTONS LOCATED ONE WITHIN EACH CYLINDERS, AND ADJUSTABLE CAM MEANS TO MOVE SAID PISTONS AXIALLY ALONG AXIS OF ROTATION AS SAID BARREL IS ROTATED, THAT IMPROVEMENT FOR PERMITTING SILENT FLOW BETWEEN SAID CYLINDERS AND SAID INLET AND OUTLET, WHICH COMPRISES INN COMBINATION WITH SAID MACHINE: A VALVE PLATE HAVING A PLURALITY OF APERTURES AND A PLURALITY OF VALVE CONTROLLED PASSAGES THEREIN; AND AN OVERHAULING VALVE MEANS INCLUDING A MOVABLE VALVE MEMBER, THE POSITION OF WHICH IS DETERMINED BY THE PRESSURE DIFFERENTIAL EXISTING BETWEEN SAID INLET AND OUTLET; SAID VALVE PLATE APERTURES ALSO COMPRISING A PAIR OF SPACED OPPOSED ELONGATED MAIN PORTS AND TWO PAIRS OF SPACED OPPOSED AUXILIARY PORTS, EACH OF SAID AUXILIARY PORTS COMMUNICATING WITH A PAIR OF VALVE CONTROLLED PASSAGES, THE PAIR BEING COMPRISED OF ONE PASSAGE HAVING AN INFLOW VALVE AND OF ONE PASSAGE HAVING AN OUTFLOW VALVE; EACH OF SAID FOUR PAIR OF PASSAGES BEING CONNECTED TO A FLOW REVERSING VALVE MEANS WHICH ALTERNATELY CLOSES ONE OF THE PASSAGES OF EACH PAIR AND OPENS THE OTHER OF SAID PASSAGES, THE DIRECTION OF FLUID FLOW WITHIN SAID MACHINE DETERMINING WHICH PASSAGE OF EACH PAIR WILL BE OPEN AND WHICH WILL BE CLOSED, THE PASSAGES BEING ARRANGED SO THAT THE OPEN PASSAGES WILL ALWAYS COMPRISE TWO OUTFLOW PASSAGES AND TWO IN FLOW PASSAGES, AND THUS THE CLOSED PASSAGES WILL ALWAYS COMPRISE THE SAME, ONE OF SAID PASSAGES CONNECTING ITS ASSOCIATED AUXILIARY PORT TO ONE OF SAID MAIN PORTS, ANOTHER OF SAID PASSAGES CONNECTING ITS ASSOCIATED AUXILIARY PORT TO THE OTHER OF SAID MAIN PORTS, THE OTHER TWO AUXILIARY PORTTS BEING CONNECTED BY SAID PASSAGES TO SAID OVERHAULING VALVE MEANS WHICH ALTERNATELY CONNECTS SUCH ASSOCIATED AUXILIARY PORTS TO ONE OR THE OTHER OF SAID MAIN PORTS DEPENDING UPON THE POSITION OF SAID MOVABLE VALVE MEMBER, WHICH IN TURN DEPENDS UPON WHETHER THE MACHINE IS OPERATING AS A PUMP OR AS A FLUID MOTOR; TWO OF SAID AUXILIARY PORTS HAVING VALVE CONTROLLED PASSAGES WHICH ALLOW ONLY INFLOW TO THEIR ASSOCIATED AUXILIARY PORTS AND THE OTHER TWO OF SAID AUXILIARY PORTS HAVING VALVE CONTROLLED PASSAGES WHICH ALLOW ONLY OUTFLOW FROM THEIR ASSOCIATED AUXILIARY PORTS, SAID PASSAGES BEING SO CONNECTED THAT ONE INFLOW AND ONE OUTFLOW PASSAGE CONNECT TO SAID OVERHAULING VALVE MEANS, AND ONE INFLOW AND ONE OUTFLOW PASSAGE CONNECT TO SAID MAIN PORTS.