Variable displacement pump

Claim 1

IN A FLUID ENERGY TRANSLATING DEVICE, A CASING DEFINING A CHAMBER HAVING INNER AND OUTER ENDS, A PORT MEMBER AFFIXED AT THE INNER END OF SAID CHAMBER AND HAVING FLAT PLANAR SURFACE MEANS FACING THE OUTER END THEREOF WITH INLET AND OUTLET PORTS ANGULARLY SPACED THEREIN ALONG ARCS OF A CIRCLE, A DRIVE SHAFT EXTENDING FROM END TO END THROUGH SAID CHAMBER, BEARING MEANS ROTATABLY SUPPORTING SAID DRIVE SHAFT IN SAID CASING, A SWASH PLATE MOUNTED IN SAID CHAMBER AND SPACED TOWARDS THE OUTER END THEREOF FROM SAID PORT MEMBER, A CYLINDER BARREL AFFIXED ON SAID SHAFT FOR MOVEMENT THEREWITH AND HAVING INNER AND OUTER ENDS RESPECTIVELY FACING THE PORT MEMBER AND THE SWASH PLATE, A PLURALITY OF CYLINDERS ANGULARLY SPACED ABOUT THE ROTATIVE AXIS OF THE BARREL AND HAVING INNER AND OUTER END PORTIONS RESPECTIVELY DISPOSED TOWARDS THE PORT MEMBER AND SWASH PLATE; PISTONS RECIPROCATING IN THE OUTER END PORTIONS OF SAID CYLINDER AND HAVING FORCE TRANSMITTING MEANS THEREON ENGAGING SAID SWASH PLATE FOR CAMMING SAID PISTONS IN ONE DIRECTION TOWARDS THE INNER END PORTIONS OF SAID CYLINDERS DURING ONE PHASE OF ROTATION OF SAID SHAFT, RETURN STROKE MEANS FOR FORCING SAID PISTONS IN THE OPPOSITE DIRECTION DURING ANOTHER PHASE OF ROTATION OF SAID SHAFT, A ROTATING WEAR PLATE HAVING AN OUTER SURFACE ADJACENT THE INNER END OF SAID BARREL AND AN INNER SURFACE SLIDINGLY ENGAGING THE FLAT PLANAR SURFACE MEANS OF SAID PORT MEMBER, SAID ROTATINGH WEAR PLATE HAVING A PLURALITY OF PASSAGES THERETHROUGH HAVING CIRCULAR OUTER ENDS AND INNER ENDS RESPECTIVELY REGISTERING WITH SAID CYLINDERS AND SAID PORTS, CYLINDRICAL SEATS IN THE OUTER SURFACE OF SAID WEAR PLATE RESPECTIVELY SURROUNDING THE OUTER ENDS OF SAID PASSAGES, SAID BARREL HAVING RIGHT CYLINDRICAL ENLARGEMENTS OF SAID CYLINDERS AT THE INNER END PORTIONS THEREOF, CYLINDRICAL SLEEVES HAVING CIRCULAR INNER END AND OUTER END PORTIONS SLIDABLY ENGAGING RESPECTIVELY IN SAID CYLINDRICAL SEATS AND ENLARGEMENTS AND CONSTITUTING COMBINED FLUID TRANSMITTING AND FLUIDSEAL MEANS BETWEEN SAID BARREL AND SAID ROTATING WEAR PLATE, THE INNER DIAMETERS OF THE SLEEVES BEING SUBSTANTIALLY EQUAL TO THE DIAMETERS OF THE OUTER ENDS OF SAID PASSAGES.