An internal combustion may include a cylinder having a first combustion chamber at one end and a second combustion chamber at an opposing end, first and second cylinder heads located at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted therein. The piston may be configured to move in a first stroke that includes an expansion stroke portion and a non-expansion stroke portion. The engine may further include first and second piston rod portions extending from opposite faces of the piston. A recess in the piston rod portions may be configured to communicate gases between a combustion chamber and locations outside the cylinder. There may also be a chamber surrounding the first or second piston rod portion, the chamber configured to be supplied with gas and the chamber being isolated from the first combustion chamber and the second combustion chamber.

Disclosed are two system devices for stratified injecting the recirculated exhaust gas and high-specific-heat-capacity or inert gas for clean combustion of an internal combustion engine. The former is composed of an exhaust gas recirculation system, an injection system, and a power system. The latter is composed of four parts, and a high-specific-heat-capacity gas or inert gas channel is added. Injectors can be arranged at any position in the cylinder between a top dead center and a bottom dead center of a piston in a cylinder; 1-3 layers of injectors can be arranged; and 2-6 injectors can be arranged on each layer. Gas participating in combustion enters the cylinder from two intake channels, namely, a scavenging port of the internal combustion engine and the injectors; an in-cylinder swirl ratio can be remarkably increased through kinetic energy carried by the gas; and fuel-gas mixing is promoted, and the combustion rate is increased.

A Schnuerle scavenging two-stroke engine is provided that can keep combustion stability in a wide rotation speed range while suppressing blow-by. The engine of the present invention is a Schnuerle scavenging two-stroke engine (2). A scavenging passage (14(in1)) related to at least one scavenging port (16(in1)) has, at its upper end portion (14a(in1)), an intake-side wall surface (204). The intake-side wall surface (204) defines a first flow direction (42) of scavenging gas discharged from the scavenging port (16(in1)) at a height level of the scavenging port (16(in1)). The upper end portion (14a(in1)) of the scavenging passage (14(in1)) related to the scavenging port (16(in1)) has a guide portion (50) defining a second flow direction (44) of scavenging gas discharged from the scavenging port (16(in1)). The second flow direction (44) is deflected to the intake side from the first flow direction (42) at the height level of the scavenging port (16(in1)).

A Schnuerle scavenging two-stroke engine is provided that can keep combustion stability in a wide rotation speed range while suppressing blow-by. The engine of the present invention is a Schnuerle scavenging two-stroke engine (2). A scavenging passage (14(in1)) related to at least one scavenging port (16(in1)) has, at its upper end portion (14a(in1)), an intake-side wall surface (204). The intake-side wall surface (204) defines a first flow direction (42) of scavenging gas discharged from the scavenging port (16(in1)) at a height level of the scavenging port (16(in1)). The upper end portion (14a(in1)) of the scavenging passage (14(in1)) related to the scavenging port (16(in1)) has a guide portion (50) defining a second flow direction (44) of scavenging gas discharged from the scavenging port (16(in1)). The second flow direction (44) is deflected to the intake side from the first flow direction (42) at the height level of the scavenging port (16(in1)).

A uniflow engine includes a cylinder having a cylinder wall, an inlet channel, an extension of a central axis of the inlet channel first intersecting the cylinder wail in a first portion of the cylinder and next intersecting the cylinder wail in a second portion of the cylinder opposite the first portion of the cylinder, an intake air gallery, the intake air gallery having a gallery wall and being in flow communication with the inlet channel, and a plurality of intake ports extending between the cylinder wail and the gallery wall, at least some of the intake ports having different areas at the cylinder wall measured perpendicular to longitudinal axes of the intake ports, and wherein an area of at least one in take port in the first portion of the cylinder is larger than an area of at least one intake port in the second portion of the cylinder.

In an internal combustion engine, first and second rotating members, one for the intake valve and one for the exhaust valve rotate next to the outside of an engine cylinder on opposite sides thereof when driven by a drive gear attached to the end of the engine's crankshaft. Each rotating member may include a ring gear having a valve port or aperture near its perimeter that cyclically aligns with a corresponding valve port formed through the cylinder wall near the top of the cylinder. A method of controlling valve timing comprises the steps of causing the rotating member containing the second valve port to periodically align in synchronism with the first port to control the passage of an air/fuel mixture and exhaust gases through the combustion cycles of the engine.

In an internal combustion engine, first and second rotating members, one for the intake valve and one for the exhaust valve rotate next to the outside of an engine cylinder on opposite sides thereof when driven by a drive gear attached to the end of the engine's crankshaft. Each rotating member may include a ring gear having a valve port or aperture near its perimeter that cyclically aligns with a corresponding valve port formed through the cylinder wall near the top of the cylinder. A method of controlling valve timing comprises the steps of causing the rotating member containing the second valve port to periodically align in synchronism with the first port to control the passage of an air/fuel mixture and exhaust gases through the combustion cycles of the engine.

The present invention relates to a piston (10) for an internal combustion engine, which has a piston skirt (14) as well as a piston head (13) having a circumferential ring belt (21) and having a circumferential cooling channel (24) closed off with a closure element (26), wherein a circumferential recess (23) is formed between the piston head (13) and the piston skirt (14). According to the invention, it is provided that the closure element (26) consists of at least two subcomponents (27, 28), that each subcomponent (27, 28) has a radially oriented base plate (29) and at least one circumferential collar (31) oriented axially on the outer edge (29a) of the base plate (29), which collar is accommodated in at least one outer fold (34) that runs underneath the ring belt (21).

A laminar-scavenging two-cycle engine which has a high laminar-scavenging effect, includes a scavenging passage having a crankcase side portion extending along a crankcase, and a cylinder side portion extending along a cylinder and having a length larger than the sum of the diameter and stroke of the cylinder. An ambient air introducing passage for introducing leading air into the scavenging passage is connected to an intermediate portion of the scavenging passage. A notch for opening a scavenging port to the side of the crankcase when a piston is near the top dead center is formed in the piston.

A laminar-scavenging two-cycle engine which has a high laminar-scavenging effect, includes a scavenging passage having a crankcase side portion extending along a crankcase, and a cylinder side portion extending along a cylinder and having a length larger than the sum of the diameter and stroke of the cylinder. An ambient air introducing passage for introducing leading air into the scavenging passage is connected to an intermediate portion of the scavenging passage. A notch for opening a scavenging port to the side of the crankcase when a piston is near the top dead center is formed in the piston.