Internal combustion engines having multi-stage telescoping poppet valves in lieu of conventional poppet valves are disclosed. The engines may have pistons with a skirt with a field of pockets that provide a ringless, non-lubricated, seal equivalent. The piston heads may include one or more depressions and may be domed to facilitate the movement of air/charge in the cylinder. The engines may also have non-circular, preferably rectangular, cross-section pistons and cylinders. The engines also may include a split crankshaft. The engines may use the pumping motion of the engine piston to supercharge the cylinder with air/charge. The engines also may operate in an inverted orientation in which the piston is closer to the local gravitationally dominant terrestrial body's center of gravity at top dead center position than at bottom dead center position.

Internal combustion engines having non-circular, preferably rectangular, cross-section pistons and cylinders are disclosed. The pistons may include a skirt with a field of pockets that provide a ringless, non-lubricated, seal equivalent. The pistons also may have a domed piston head with depressions thereon to facilitate the movement of air/charge in the cylinder. The engines also may use multi-stage poppet valves in lieu of conventional poppet valves, and a split crankshaft. The engines may use the pumping motion of the engine piston to supercharge the cylinder with air/charge. The engines also may operate in an inverted orientation in which the piston is closer to the local gravitationally dominant terrestrial body's center of gravity at top dead center position than at bottom dead center position.

An internal combustion engine includes an engine main body defining a cylinder bore, a piston received in the cylinder bore, and a crankshaft rotatably supported by the engine main body and connected with the piston via a connecting rod, the piston including a skirt. The cylinder bore includes a first region defined as a range along the cylinder axial line on a side of a top dead center from a first piston position, and a second region defined as a range along the cylinder axial line on a side of the bottom dead center from a second piston position closer to the bottom dead center than the first piston position, and a connection region positioned between the first and second regions. A diameter of the cylinder bore is smaller in the first region than in the second region, and the connection region connects the first and second regions smoothly.

An internal combustion engine includes: a cylinder in which a piston reciprocates; a cylinder head positioned above the cylinder; a gasket disposed between the cylinder and the cylinder head; a stepped portion that is formed at an upper end portion of an inner peripheral surface of the cylinder and positioned below the gasket; a ring member having a cylindrical shape provided to the stepped portion; and a protrusion portion that is formed in a manner to protrude from the ring member and bites into a lower surface of the gasket.

The present invention relates to an internal-combustion engine comprising a combustion chamber provided with a single intake valve (2), a single exhaust valve (3), two plugs (4a, 4b) and a fuel injector (5). Furthermore, the combustion chamber comprises means for forming an aerodynamic swirling motion structure of the intake gas in the combustion chamber. Besides, fuel injector (5) is oriented so as to inject the fuel into the central area of the combustion chamber in the direction of the aerodynamic swirling motion structure.

The present invention relates to a combustion chamber of a combustion engine. The combustion chamber comprises a single intake valve (2), a single exhaust valve (3), a fuel injector (5) and two plugs (4). According to the invention, the combustion chamber is substantially elliptical (6) and the components of the combustion chamber are arranged as follows: valves (2, 3) are located at the ends of the major axis (8) of ellipse (6), plugs (4) are located close to the minor axis (9) of ellipse (6), fuel injector (5) is located on the periphery of ellipse (6) between intake valve (2) and a plug (4).

The present invention relates to an internal-combustion engine comprising at least two cylinders wherein a piston in connection with a combustion chamber moves. Said combustion chamber comprises a single intake valve (SA), a single exhaust valve (SE), a single fuel injector (ID), two spark plugs (Al) and means for creating a swumble flow in said chamber.

According to one embodiment, a drive device includes a first piston reciprocatively along a first direction within a first mount plane, a first crankshaft orthogonal to the first mount plane, a first XY separation crank mechanism between the first piston and the first crankshaft, which converts reciprocating motion of the first piston and rotary motion of the first crankshaft into each other, a second piston reciprocatively along a second direction symmetrical to the first direction within a second mount plane symmetrical to the first mount plane about a central reference plane, a second crankshaft orthogonal to the second mount plane, a second XY separation crank mechanism between the second piston and the second crankshaft, which converts reciprocating motion of the second piston and rotary motion of the second crankshaft into each other, and a coupler-synchronizing mechanism which rotates the first and second crankshafts in synchronous with each other.

Internal combustion engines having pistons with one or more depressions located on the piston head to facilitate the movement of air/charge in the cylinder are disclosed. The pistons may include a skirt with a field of pockets that provide a ringless, non-lubricated, seal equivalent. The piston head also may be domed to further facilitate the movement of air/charge in the cylinder. The engines may also have non-circular, preferably rectangular, cross-section pistons and cylinders. The engines also may use multi-stage poppet valves in lieu of conventional poppet valves, and may include a split crankshaft. The engines may use the pumping motion of the engine piston to supercharge the cylinder with air/charge. The engines also may operate in an inverted orientation in which the piston is closer to the local gravitationally dominant terrestrial body's center of gravity at top dead center position than at bottom dead center position.

Internal combustion engines having non-circular, preferably rectangular, cross-section pistons and cylinders are disclosed. The pistons may include a skirt with a field of pockets that provide a ringless, non-lubricated, seal equivalent. The pistons also may have a domed piston head with depressions thereon to facilitate the movement of air/charge in the cylinder. The engines also may use multi-stage poppet valves in lieu of conventional poppet valves, and a split crankshaft. The engines may use the pumping motion of the engine piston to supercharge the cylinder with air/charge. The engines also may operate in an inverted orientation in which the piston is closer to the local gravitationally dominant terrestrial body's center of gravity at top dead center position than at bottom dead center position.