Variable positive fluid displacement system

A variable positive fluid displacement apparatus comprising

• a crankshaft,
• a crankcase surrounding said crankshaft,
• first and second chambers,
• a first piston assembly slideably positioned within said first chamber having first and second spaced leg members,
• a second piston assembly slideably positioned within said second chamber having third and fourth spaced leg members,
• first piston drive means connected at spaced positions on said crankshaft to said first and second leg members for reciprocating said first piston assembly, and
• second piston drive means connected at spaced positions on said crankshaft to said third and fourth leg members for reciprocating said second piston assembly

In a fluid displacement apparatus, the method comprising the steps of

• providing a displacement chamber,
• positioning in said chamber a piston having a plurality of fluid ports,
• guiding said piston for reciprocating movement along an axis in said chamber while restraining said piston from angular movement with respect to said axis,
• positioning in face-to-face relationship with said piston a port plate having a plurality of fluid ports,
• guiding said port plate for movement parallel with and transverse to said axis while restraining said port plate from angular movement with respect to said axis,
• driving said port plate with a circular motion whereby the surface of said port plate adjacent said piston describes a circular path while remaining in a plane perpendicular to said axis, the transverse component of movement of said port plate cyclically changing the alignment of said ports in said port plate relative to those in said piston and the component of movement of said port plate parallel with said axis causing reciprocating motion of said piston.