Reciprocating hydraulic motor with a differential piston
AssigneeSociete Civile De Recherche Sam
InventorPhilippe Cloup
Life of this patent
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Abstract
The invention relates to a reciprocating hydraulic motor having a differential piston interposed between an inlet pipe for fluid at a pressure P1 and an exhaust pipe for fluid at a pressure P2 which is less than the pressure P1 The moving assembly constituted by the different-section pistons that slide in a stepped cylinder includes a flap having two positions and controlling three ports, the flap being mounted to pivot about an axis. In each of its positions, the flap bears against two wall portions disposed on opposite sides of the flap and at different distances from the pivot axis so that the effect of the pressures P1 and P2 on the faces of the flap is to establish a positive closure torque.
Claims9
A reciprocating hydraulic motor having a differential piston interposed between an inlet duct for communicating a fluid at a pressure P1 and an exhaust duct for communicating a fluid at a pressure P2 less than P1, and comprising:
- a stepped cylinder;
- a moving assembly including a cavity and two interconnected pistons of different sections, mounted to slide in sealing engagement with inside portions of the stepped cylinder and defining three variable-volume chambers including an inlet chamber interposed between said two pistons and in communication with said inlet duct, an exhaust chamber situated on a side of the piston with a smaller section which is opposite to said inlet chamber and in communication with said exhaust duct, and an intermediate chamber situated on a side of the piston with a larger section which is opposite to said inlet chamber;
- a first passage for temporarily placing said inlet chamber in communication with said intermediate chamber;
- a second passage for temporarily placing said intermediate chamber in communication with said exhaust chamber;
- and
- control means for alternatingly opening and closing said first and second passages during each of a plurality of operating cycles;
- wherein said first passage and said second passage are formed by said cavity and by three ducts for placing said cavity in communication with said inlet chamber, with said exhaust chamber, and with said intermediate chamber, respectively;
- and
- wherein said control means includes a single flap disposed in said cavity and pivotally mounted on a pivot shaft situated in a plane defined by said flap and extending substantially perpendicular to a plane defined by said ducts, and actuator means for operating said flap and operatively associated with said moving assembly, for moving said flap between two different positions during each of said operating cycles including a first position in which said inlet chamber communicates with said intermediate chamber, and said exhaust chamber is isolated, and a second position in which said intermediate chamber communicates with said exhaust chamber, and said inlet chamber is isolated.
Dependencies are inferred from the claim text.