Patent ID: 6470677
Filing Date: 2002-10-29
Classification: F02B

Abstract:
A free piston engine system, comprising:at least one hydraulic pump, each said pump having a first fluid port and a second fluid port; a free piston internal combustion engine including a combustion cylinder having a single respective hydraulic cylinder associated therewith, a piston reciprocally disposed within said combustion cylinder, and a single plunger attached to said piston, said plunger being disposed within said hydraulic cylinder; a low pressure accumulator fluidly coupled with said hydraulic cylinder; a first control valve interconnecting said low pressure accumulator with said hydraulic cylinder; at least one high pressure accumulator fluidly coupled with said hydraulic cylinder; at least one second control valve, each said second control valve interconnecting a respective said high pressure accumulator with said hydraulic cylinder; a third control valve interconnecting said hydraulic cylinder with said first fluid port of each said pump; a fourth control valve interconnecting said hydraulic cylinder with said second fluid port of each said pump; and a first working pressure accumulator coupled between each said pump and one of said third control valve and said fourth control valve.