Free-piston engine
OwnerAlan Kent Johnsoninventor
Life of this patent
Estimating the term…
Abstract
A multicylinder internal combustion free-piston engine (FPE) with synchronized reciprocating plungers. The invention provides a solution for the problem of the slow engine speed typical of FPE's with heavy plunger mass. Bounce chambers fitted with sleeve valves control the engine's speed and stroke length. The invention's configuration prevents piston head-strikes and operates at standard compression ratios. Piston “pop-top” intake valves allow uniflow scavenging and connecting rod oil channels provide lubrication with no combustion chamber contamination. Poppet combustion head valves are operated by linear cams attached to the plungers. Hydraulic valve actuators implement variable valve timing under computer control.
Claims12
A two-stroke internal combustion free-piston engine comprising:
- two or more reciprocating gear racks;
- two or more power pistons;
- two or more bounce pistons;
- a power cylinder for each power piston arranged with its power piston reciprocating within the power cylinder;
- a power head for each power cylinder for enclosing the outboard side of the power cylinder to form a combustion chamber;
- a bounce chamber for each bounce piston comprising a bounce cylinder and bounce cylinder ceiling, arranged with its bounce piston reciprocating within the bounce cylinder, and arranged to trap and compress a mass of air within the bounce chamber during the bounce piston's upstroke;
- a bounce valve for each bounce chamber arranged to vary the mass of air trapped within the bounce chamber during its bounce piston's upstroke;
- at least one pinion gear engaging the gear racks and arranged so that the reciprocating motion of each gear rack produces an opposing reciprocating motion of at least one other gear rack;
- wherein each said power piston is connected to a said gear rack and each said bounce piston is connected to a said gear rack, with the power pistons and the bounce pistons and the gear racks arranged to form at least two reciprocating plungers;
- wherein said plungers and said bounce chambers and said combustion chambers and said at least one pinion gear are arranged so the compression stroke of each power piston is mechanically linked to the compression stroke of at least one bounce piston.
Dependencies are inferred from the claim text.