The invention discloses a two-stroke internal combustion engine having an engine housing with a crankcase in which a crankshaft is connected to a piston moving in a cylinder, an exhaust port leading from the cylinder space and opening at the level of the lower dead center of the crankshaft, the exhaust port is configured to be closed by a piston when the crankshaft is in its top dead center position, characterized in that it further has a rotary disk with an opening or recess on a part of its circumference, or with a protrusion on a part of its circumference, the rotary disk extending with its circumference into the exhaust port so that the exhaust port is completely closable by the rotary disk.

The invention discloses a two-stroke internal combustion engine having an engine housing with a crankcase in which a crankshaft is connected to a piston moving in a cylinder, an exhaust port leading from the cylinder space and opening at the level of the lower dead center of the crankshaft, the exhaust port is configured to be closed by a piston when the crankshaft is in its top dead center position, characterized in that it further has a rotary disk with an opening or recess on a part of its circumference, or with a protrusion on a part of its circumference, the rotary disk extending with its circumference into the exhaust port so that the exhaust port is completely closable by the rotary disk.

Provided is a two-stroke internal combustion engine, including: a fuel injection valve configured to supply a fuel into a crank chamber; an intake passage configured to allow only air to be sucked thereinto under a negative pressure generated when a piston is actuated; and a scavenging passage that allows communication between the crank chamber and a combustion chamber. Further, air passing through the intake passage is introduced into the scavenging passage, and air stagnant in the scavenging passage at end of air suction contributes to scavenging.

Provided is a two-stroke internal combustion engine, including: a fuel injection valve configured to supply a fuel into a crank chamber; an intake passage configured to allow only air to be sucked thereinto under a negative pressure generated when a piston is actuated; and a scavenging passage that allows communication between the crank chamber and a combustion chamber. Further, air passing through the intake passage is introduced into the scavenging passage, and air stagnant in the scavenging passage at end of air suction contributes to scavenging.

A breather chamber for an internal combustion engine wherein the breather chamber has a large size that is formed while an increase in the size of the internal combustion engine is suppressed. The breather chamber of an internal combustion engine includes looped cam chains for transmitting the power of a horizontally disposed crankshaft to camshafts provided in cylinder heads and includes cam chain chambers disposed alongside portions of cylinder block portions which intersect the direction of the crankshaft. The breather chamber is located on a side of a plane formed by a rotation locus of the cam chain in the direction of the crankshaft in the cam chain chamber.

The invention provides an internal combustion engine comprising a piston mounted for reciprocating linear motion within a cylinder along a cylinder axis. The piston is coupled to an output shaft by a power transfer assembly arranged to convert linear motion of the piston to rotary motion of the output shaft. The piston has a first head moveable within a first chamber and a second head opposite the first head and moveable within a second chamber. The power transfer assembly has a lubrication system for lubricating moving components of the power transfer assembly. The lubrication system is sealed from the first chamber and the second chamber to prevent the passage of fluid from the lubrication system into the first chamber and the second chamber.

The invention provides an internal combustion engine comprising a piston mounted for reciprocating linear motion within a cylinder along a cylinder axis. The piston is coupled to an output shaft by a power transfer assembly arranged to convert linear motion of the piston to rotary motion of the output shaft. The piston has a first head moveable within a first chamber and a second head opposite the first head and moveable within a second chamber. The power transfer assembly has a lubrication system for lubricating moving components of the power transfer assembly. The lubrication system is sealed from the first chamber and the second chamber to prevent the passage of fluid from the lubrication system into the first chamber and the second chamber.

A separator device for a system for recirculation of the blow-by gases of an internal combustion engine includes a casing containing a separation chamber and having an inlet for communication with the engine crankcase and an outlet for communication with the engine intake manifold, and drainage outlets ending in the engine crankcase, for returning the liquid separated in the separation chamber into the engine crankcase. Actuator means sensitive to pressure in the engine crankcase are associated to the inlet and to the drainage outlets so that when the pressure in the engine crankcase is higher than the pressure in the separator device, the inlet is open and the drainage outlets are closed, while when the pressure in the engine crankcase is lower than the pressure in the separator device, the inlet is closed and the drainage outlets are open.

A vibration-type oil separator includes a housing having a blow-by gas entering path through which a blow-by gas enters, an oil-discharging path which discharges an oil separated from the blow-by gas to outside, and a gas-discharging path which discharges a gas obtained by separating the oil from the blow-by gas to the outside. A vibration cylinder has an orifice formed thereon for escaping the gas and generating vibration by a back pressure of the blow-by gas and an external force applied to the housing to separate the oil and the blow-by gas. A fixing rod fixes the vibration cylinder in an internal space of the housing, in which both side portions thereof are fixed to the housing and a central portion thereof is fixed to the vibration cylinder.

An internal combustion engine for an automotive vehicle has an intake manifold receiving fresh air via an inlet duct. The engine includes a crankcase. A turbocharger is provided having a compressor with an inlet coupled to the inlet duct and an outlet coupled to the intake manifold. A first vent line couples the crankcase with the compressor inlet. A second vent line couples the crankcase with the compressor outlet and intake manifold. The second vent line has a valve blocking air flow into the crankcase and allowing air flow out from the crankcase. The first vent line comprises a dual-acting valve having a first flow capacity into the crankcase and a second flow capacity out from the crankcase which is greater than the first flow capacity. Thus, crankcase ventilation is optimized for both engine idle and high engine load conditions.