Reversible rotary piston motors of the screw rotor type

Claim 1

A REVERSIBLE ROTARY PISTON MOTOR COMPRISING A CASING STRUCTURE PROVIDING A BARREL PORTION WITH INTERSECTING BORES HAVING COPLANAR AXES LOCATED BETWEEN END WALL PORTIONS FORMING A WORKING SPACE AND FURTHER PROVIDING DIAGONALLY LOCATED SPACED APART PORTS FOR ADMISSION AND EXHAUST OF MOTIVE FLUID TO AND FROM SAID WORKING SPACE, A FIRST ONE OF SAID PORTS BEING LOCATED ON ONE SIDE OF THE PLANE OF SAID AXES AT ONE END OF SAID BORES AND A SECOND ONE OF SAID PORTS BEING LOCATED ON THE OPPOSITE SIDE OF SAID PLANE AT THE OPPOSITE END OF SAID BORES, ROTORS HAVING A WRAP ANGLE OF LESS THAN 360* COMPRISING A MALE ROTOR HAVING LANDS PROVIDED WITH CONVEXLY CURVED FLANKS AND INTERVENING GROOVES THE MAJOR PORTIONS OF WHICH LIE OUTSIDE THE PITCH CIRCLE OF THE MALE ROTOR AND A FEMALE ROTOR HAVING LANDS PROVIDED WITH CONCAVELY CURVED FLANKS AND INTERVENING GROOVES THE MAJOR PORTIONS OF WHICH LIE INSIDE THE PITCH CIRCLE OF THE FEMALE ROTOR, THE LANDS AND GROOVES OF SAID ROTORS INTERMESHING TO FORM WITH CONFRONTING PORTIONS OF THE CASING STRUCTURE A FIRST AND A SECOND SERIES OF CHEVRON-SHAPED WORKING CHAMBERS, THE DIFFERENT SERIES OF CHAMBERS BEING FORMED RESPECTIVELY ON OPPOSITE SIDES OF SAID PLANE OF SAID AXES WITH THE BASES OF THE CHAMBERS BEING DEFINED BY THE PLANES OF THE RESPECTIVELY OPPOSITE END WALL PORTIONS OF THE CASING STRUCTURE AT WHICH SAID PORTS ARE RESPECTIVELY LOCATED AND THE APEXES OF THE WORKING CHAMBERS OF SAID FIRST SERIES MOVING AXIALLY AWAY FROM THE BASE PLANE THEREOF WHILE THE APEXES OF SAID SECOND SERIES OF CHAMBERS SIMULTANEOUSLY MOVE IN THE SAME AXIAL DIRECTION TOWARD THE BASE PLANE OF SAID SECOND SERIES OF CHAMBERS WHEN THE ROTORS TURN IN INTERMESHING RELATION TO PROVIDE A GIVEN DIRECTION OF OPERATION FOR THE MOTOR, WHEREBY THE VOLUMES OF THE CHAMBERS OF SAID FIRST SERIES INCREASE AND THE VOLUMES OF THE CHAMBERS OF SAID SECOND DECREASE AS THE ROTORS REVOLVE, SAID APEX MOVING AXIALLY IN THE OPPOSITE DIRECTION TO CAUSE THE CHAMBERS OF SAID FIRST AND SAID SECOND SERIES TO DECREASE AND INCREASE RESPECTIVELY WHEN SAID ROTORS REVOLVE TO REVERSE THE DIRECTION OF OPERATION FROM SAID GIVEN DIRECTION, REVERSING VALVE MEANS FOR SELECTIVELY CAUSING SAID MOTOR TO OPERATE IN DESIRED DIRECTION COMPRISING A REVERSIBLE VALVE COMPONENT MOVABLE TO DIRECT MOTIVE FLUID TO ONE OR TO THE OTHER OF SAID PORTS TO BE EXPANDED IN ONE OR THE OTHER OF SAID SERIES OF CHAMBERS AND AUXILIARY VALVE MEANS ASSOCIATED WITH EACH OF SAID PORTS AUTOMATICALLY OPERABLE TO ENLARGE THE EFFECTIVE AREA OF THE PORT NOT RECEIVING MOTIVE FLUID, WHEREBY TO PROVIDE AN APPROPRIATE EXHAUST AREA FOR EXHAUSTING EXPANDED MOTIVE FLUID FROM SAID WORKING SPACE OF THE MOTOR.