Patent ID: 6293231
Filing Date: 2001-09-25
Classification: B60K,F02B,F02M,Y02T

Abstract:
A free-piston internal combustion pump-engine comprising:a housing including a piston bore;at least one free-piston, reciprocably mounted within the piston bore for movement between a bottom-end position and a top-end position during expansion and compression strokes, the free-piston having a drive end and a combustion end,the drive end of the free-piston including a first axial face and a second axial face cooperating with the piston bore to define a first chamber and a second chamber,the combustion end of the free-piston cooperating with the piston bore to at least partially define a combustion chamber; anda fluid flow control system for the drive end of the free-piston, the fluid flow control system variably pressurizing said first and second axial faces of the drive end for providing varying axial forces at the free-piston during both the compression stroke to compress combustion air during the compression stroke and the combustion stroke to extract work during the combustion stroke,the fluid flow control system including at least a first fluid flow control device, at least one non-return valve, and first and second fluid conduits, the first fluid conduit providing fluid communication between the first chamber and a first source of pressurized fluid to supply pressurized fluid to the first chamber during a first portion of the compression stroke and to return pressurized fluid from the first chamber to the first source of pressurized fluid during a portion of the combustion stroke of the free piston, the non-return valve providing fluid communication between the first chamber and a fluid reservoir during a suction portion of the compression stroke, and the second fluid conduit and the first fluid flow control device providing fluid communication between the second chamber and the first fluid conduit independently of the position of the free-piston to supply the second chamber with pressurized fluid from the first fluid conduit during a portion of the compression stroke following said suction portion and during a portion of the combustion stroke.