Abstract: A Positive Fluid Displacement Device (PFDD) with single piece double-ended pistons connected to a crankpin for circular motion. Pistons are nested together to maintain all pistons in the same plane perpendicular to the axis of the crankshaft. Cylinders are driven in a reciprocating fashion by the pistons and are held loosely in a cylinder carriage along its axis with radial sealing engagement therebetween. Pliable members mount port plates within a housing such that there is no direct contact therebetween or with a two-layer manifold. A flat surface of the port plate is urged against the cylinder head by a pliable member which exerts a force on the center of the port plate. Grooves in the first layer of the manifold are sealed by the second layer to form fluid passageways. The cylinder head is guided in housing grooves with a pliable member. A sealing lip is integral with a piston head.

Abstract: A Positive Fluid Displacement Device (PFDD) with single piece double-ended pistons connected to a crankpin for circular motion. Pistons are nested together to maintain all pistons in the same plane perpendicular to the axis of the crankshaft. Cylinders are driven in a reciprocating fashion by the pistons and are held loosely in a cylinder carriage along its axis with radial sealing engagement therebetween. Pliable members mount port plates within a housing such that there is no direct contact therebetween or with a two-layer manifold. A flat surface of the port plate is urged against the cylinder head by a pliable member which exerts a force on the center of the port plate. Grooves in the first layer of the manifold are sealed by the second layer to form fluid passageways. The cylinder head is guided in housing grooves with a pliable member. A sealing lip is integral with a piston head.

Abstract: A Positive Fluid Displacement Device (PFDD) with a removable Fluid Displacement Module (FDM) having two opposing pistons connected to a drive block. The drive block slides over a crankpin bearing in assembly to provide orbital piston motion. Opposing cylinders are held within a carriage for reciprocating motion. An opening in the reciprocating cylinder head allows fluid communication to the displacement chamber through inlet and outlet ports in a floating port plate. The flat surfaces of the port plate and cylinder head wipe across each other during cylinder head movement. The piston head carries a protrusion sized to fill the cylinder head opening. Micro-adjustment mechanisms for the position of the cylinder head together with compliant piston and compliant cylinder mechanisms can provide near zero dead volume. Different sized opposing cylinders enable the delivery of pumped fluids in precise ratios.