Patent ID: 6536384
Filing Date: 2003-03-25
Classification: F02B,F02M,F05C

Abstract:
A two-stroke internal combustion engine with isolated crankcase, which comprises:a sealed crankcase having an aperture and a crankshaft; a piston cylinder attached to said crankcase, said piston cylinder having a combustion chamber and also having a wall with a transfer port which has a top and a bottom and an exhaust port that has a top and a bottom with the top of the exhaust port being higher than the top of the transfer port; a piston slidably mounted within said piston cylinder, said piston connected to the crankshaft of said crankcase, and having a top, a bottom a piston seal around said piston sufficienty close to said bottom of said piston that said piston seal is always between (1) said crankcase and (2) the bottoms of the transfer port and of the exhaust port, and a pressure ring located around said piston near the top of said piston; an isolation chamber, said isolation chamber having an inner surface, a crankcase side, an intake side, a pressure-sensitive wall, said pressure-sensitive wall forming a barrier between said crankcase side and said intake side, and being substantially impervious to air, oil, and the fuels used in an internal combustion engine, a crankcase-side aperture on the crankcase side of said isolation chamber, an intake aperture on the intake side of said isolation chamber, and a third aperture on the intake side of said isolation chamber, said isolation chamber communicating with said crankcase through the crankcase-side aperture and the aperture in said crankcase, and said isolation chamber communicating with said piston cylinder through the third aperture and the transfer port; and a flow regulator connected to said isolation chamber and communicating with said isolation chamber through the intake aperture so that air may pass into, but will not escape outward through said flow regulator from, the intake side of said isolation chamber.