Pressure balanced seal-pack for reversible pumps and motors

Claim 1

IN A GEAR PUMP OF THE TYPE HAVING A CASING FORMED WITH A GROOVE SYSTEM AND A FIGURE 8-SHAPED CHAMBER HOUSING A PAIR OF INTERMESHING GEARS MOUNTED FOR ROTATION THEREIN FOR PROPELLING A FLUID BETWEEN TWO PORTS, THE IMPROVEMENT COMPRISING: A FLUID PRESSURE SEAL PACK HAVING: A GASKET AND CHANNEL-SHAPED WEB FOR SEATING WITHIN THE GROOVE SYSTEM OF SAID CASING AND EACH HAVING A GENERALLY OVALOID-SHAPED OUTER RIM SEGMENT, TWO INTERIOR CIRCULAR RING SEGMENTS WITH A MERGING BRIDGE THEREBETWEEN, AND RADIAL ARMS EXTENDING FROM EACH OF SAID CIRCULAR RING SEGMENTS AT EQUAL ANGULAR DISPLACEMENTS ON OPPOSITE SIDES OF THE MAJOR AXIS OF SAID OVAL OUTER RIM SEGMENT TO MERGE WITH SAID OUTER RIM AND FORM TOGETHER THEREWITH A KEYSTONESHAPED ZONE ABOUT SAID MAJOR AXIS BETWEEN SAID ARMS OF EACH OF SAID RING SEGMENTS AND AN OXYOKE SHAPED ZONE BETWEEN SAID BRIDGE AND THE STRAIGHT LEG PORTIONS OF SAID OVAL RIM; SAID WEB SEATING WITHIN THE GROOVE SYSTEM BEHIND SAID GASKET FOR URGING SAID GASKET TOWARD THE ADJOINING GEAR SIDE FACE; A WEAR PLATE HAVING AN OVAL SHAPE FOR SEATING IN SAID CASING IN SAID CHAMBER AND HAVING A SEALING SURFACE JUXTAPOSED TO SAID GEARS AND AN OPPOSITE MOTIVE SURFACE IN CONTACT WITH SAID GASKET, SAID WEAR PLATE HAVING PRESSURE COMMUNICATION HOLES FOR COMMUNICATING PRESSURE FROM SAID CHAMBER AXIALLY OPPOSITE SAID ZONES INTO SAID ZONES, SAID WEAR PLATE FURTHER INCLUDING A PRESSURE COMMUNICATION GROOVE FORMED IN SAID SEALING SURFACE FOR ALLOWING THE COMMUNICATION OF PRESSURE BETWEEN SAID KEYSTONE-SHAPED ZONES AND ONE OF SAID OX-YOKE SHAPED ZONES ON THE OUTLET SIDE OF THE PUMP, SAID WEAR PLATE FURTHER BEING SELECTIVELY SEATED IN REVERSE ALIGNMENT UPON SAID GASKET IN EITHER OF TWO ORIENTATIONS SO AS TO ALLOW SUCH COMMUNICATION BETWEEN SAID KEYSTONE-SHAPED ZONES AND EITHER ONE OF SAID OXYOKE SHAPED ZONES.