Patent ID: 6582204
Filing Date: 2003-06-24
Classification: F02B,F04B

Abstract:
A free-piston engine having at least one engine unit comprising:a pair of axially opposed combustion cylinders; a pair of free-floating combustion pistons respectively mounted in said combustion cylinders for reciprocating linear motion therein, responsive to successive combustion events within said combustion cylinders; a pumping piston extending from and fixed to each of said pair of combustion pistons; a pair of axially aligned hydraulic cylinders located between said pair of combustion cylinders and respectively receiving said pumping pistons for reciprocating linear motion therein; a cage rigidly connecting said pair of combustion pistons and surrounding said hydraulic cylinders and pumping pistons to form a reciprocating dual piston assembly which reciprocates as a single unit comprising said pair of combustion pistons, said pumping pistons and said cage; and ports in each of said hydraulic cylinders for admitting fluid at a first pressure and discharging fluid at a second pressure higher than the first pressure.