Patent ID: 6463895
Filing Date: 2002-10-15
Classification: F02B

Abstract:
A free piston internal combustion engine, comprising:a housing including a combustion cylinder and a single hydraulic cylinder; a piston including a piston head reciprocally disposed within said combustion cylinder and movable during a compression stroke to a top dead center position and during a return stroke to a bottom dead center position, a plunger head reciprocally disposed within said hydraulic cylinder, and a plunger rod interconnecting and rigidly affixed to each of said piston head and said plunger head, said plunger head and said hydraulic cylinder defining a variable volume pressure chamber on a side of said plunger head generally opposite said plunger rod; a hydraulic accumulator; and at least one valve interconnecting said hydraulic accumulator with said pressure chamber during a portion of said compression stroke to act on said plunger head and thereby move said piston head toward said top dead center position, and interconnecting said hydraulic accumulator with said pressure chamber during said return stroke to pressurize said hydraulic accumulator during movement of said piston head toward said bottom dead center position.