Zero leakage valveless positive fluid displacement device

A positive fluid displacement device (PFDD) for delivering a fluid comprising

• a housing for said device;
• a crankshaft mounted within said housing, said crankshaft for coupling to the driveshaft of a motor;
• a crankpin connected to said crankshaft to provide an orbital movement around said crankshaft;
• a fluid displacement module (FDM) for quick and easy assembly with said housing and said crankpin, said FDM having a first piston/cylinder assembly comprising
• a piston connected in assembly to said crankpin to operably provide said piston with a circular motion, said piston having a piston head;
• a cylinder having a cylinder head, said cylinder head having a side enclosing one end of a displacement chamber, said cylinder for holding said piston, said piston head enclosing a second end of said displacement chamber;
• said cylinder head having a flat surface on a side opposite to the side enclosing said displacement chamber;
• and
• an opening in said cylinder head, said opening allowing fluid communication to and from said displacement chamber, said piston head having a protrusion sized to empty said opening of fluid at top dead center of piston travel;
• a first port plate having a flat surface which in assembly is in sealing engagement with the flat surface of said cylinder head, said port plate having two ports for fluid communication through said opening to said displacement chamber, one port being an inlet port to said displacement chamber and one port being an outlet port from said displacement chamber, in assembly said housing and said port plate are held from direct mechanical contact therewith by interposing pliable members to bear against said housing and each said port plate thereby allowing micromotion of said port plate in two dimensions while allowing movement of said port plate to follow movement of the mating flat surface of the cylinder head;
• and
• wherein in operation, the circular movement of said crankpin imparts a reciprocating movement to said cylinder, the flat surface of said cylinder head moving back and forth across the flat surface of said port plate once per revolution of said crankpin wherein said opening is successively brought into fluid communication with said inlet port and said outlet port.

A positive fluid displacement device (PFDD) for delivering a fluid comprising

• a housing for said device;
• a crankshaft mounted within said housing, said crankshaft for coupling to the driveshaft of a motor;
• a crankpin connected to said crankshaft to provide an orbital movement around said crankshaft;
• a fluid displacement module (FDM) for quick and easy assembly with said housing and said crankpin, said FDM having a first piston/cylinder assembly comprising
• a piston having a piston head, said piston connected to said crankpin to operably provide said piston with a circular motion;
• a cylinder having a cylinder head, said cylinder head having a side enclosing one end of a displacement chamber, said cylinder for holding said piston, said piston head enclosing a second end of said displacement chamber;
• said cylinder head having a flat surface on a side opposite to the side enclosing said displacement chamber;
• and
• an opening in said cylinder head, said opening allowing fluid communication to and from said displacement chamber, said piston head having a protrusion sized to empty said opening of fluid at top dead center of piston travel;
• a first port plate having a flat surface which in assembly is in sealing engagement with the flat surface of said cylinder head, said port plate having two ports for fluid communication through said opening to said displacement chamber, one port being an inlet port to said displacement chamber and one port being an outlet port from said displacement chamber, in assembly said housing holds said port plate from direct mechanical contact therewith by interposing pliable connections to bear against said housing and each said port plate thereby allowing micromotion of said port plate in two dimensions while allowing movement of said port plate with the mating flat surface of the cylinder head;
• and
• a manifold connected in assembly to said housing, said manifold having passageways for fluid to connect inlet and outlet ports in said manifold to corresponding inlet and outlet ports in each port plate, said manifold comprising two layers, a first layer having grooves on a flat surface thereof, said second layer having a flat surface for mating with the grooved flat surface of said first layer wherein said grooves are sealed to provide said passageways.

A method of eliminating valves and achieving near dead volume in a positive fluid displacement device (PFDD) employing pistons to draw fluid into a displacement chamber and expel fluid therefrom, and to eliminate internal leakage in said PFDD, said method comprising

• providing a PFDD housing with a crankshaft and a crankpin, said crankpin providing circular motion around said crankshaft;
• providing a piston capable of being driven by said crankpin in a circular motion;
• providing a cylinder, said cylinder having a cylinder head, said cylinders capable of being driven by said crankpin in a reciprocating motion;
• providing an opening in said cylinder head for allowing fluid communication to and from the displacement chamber;
• providing a protrusion on said piston, said protrusion sized to empty said opening when the piston is at top dead center to achieve near zero dead volume in the displacement chamber;
• providing inlet and outlet ports for allowing alternating fluid communication through the opening to fill the displacement chamber on an intake stroke of the piston and to empty the displacement chamber on an exhaust stroke of the piston to achieve valveless operation;
• providing a port plate containing said inlet and outlet ports, said port plate having a flat surface for mating with a flat surface on said cylinder head to provide a sealing relationship therebetween;
• providing for a port plate mounting arrangement that allows said port plate to move in one dimension to maintain the sealing relationship with said cylinder head and to accommodate sufficient clearance of said cylinder head in two other dimensions to allow for movement in said one dimension wherein said port plate mounting arrangement includes
• providing for no direct mechanical contact between said port plate and said housing;
• and
• providing for the maintenance of sufficient force on said port plate in a dimension perpendicular to the plane of reciprocating motion to maintain said sealing relationship and thereby eliminate internal leakage in said PFDD.