An engine includes an engine housing defining a pair of cylinders, a pair of ignitor cylinders and a crankcase, a pair of cylinder heads connected to the engine housing and enclosing the pair of cylinders, a pair of spark plugs connected to the pair of cylinder heads and in communication with the pair of cylinders, a piston assembly in communication with the pair of cylinders, a rocker arm connected to the piston assembly, a connecting rod connected to the rocker arm, and a drive shaft disposed within the crankcase and connected to the connecting rod, a pair of ignitor cylinder plugs fit within the pair of ignitor cylinders, ignitor piston rod apertures formed though the engine housing, and rod aperture plugs fit within the piston rod apertures.

An internal combustion engine for providing a linear reciprocating movement of an output shaft along a longitudinal axis. The engine has a double sided cylinder that is bounded by an engine head at each side of the cylinder. An exhaust unit is positioned at each side of the cylinder. A piston is positioned within a cylinder inner space and freely slides with respect to the cylinder along the longitudinal axis. Two piston rods are aligned with the longitudinal axis. Each piston rod is connected at a different side of the piston. Each of the piston rods has exhaust openings.

A linear reciprocating engine may include an engine block, a cylinder having combustion chambers at opposing ends, cylinder heads located at an end of the respective combustion chambers, respectively, and a double-faced piston. The engine may further include piston rod portions extending from both faces of the piston through the combustion chambers. The engine may further include an exhaust outlet in a peripheral cylinder wall and elongated channels in the piston rod portions being configured to serve as an intake inlet for gas from a location external to the cylinder. When the piston is in a combustion stage in a first combustion chamber, the piston blocks the exhaust outlet from communicating with the first chamber with the first channel access opening outside the first chamber, while simultaneously the exhaust outlet is in communication with a second combustion chamber with the second channel access opening within the second chamber.

An internal combustion engine may include an engine block, a cylinder within the engine block, and a piston within the cylinder. The piston may have an outer peripheral wall, and a groove in the outer peripheral wall of the piston may have a first edge and a second edge spaced from the first edge. The piston may have a piston ring in the groove, and the piston ring may have a shape that meanders within the groove, such that the shape of the piston ring differs from a shape of the groove and such that the piston ring does not substantially fill the groove. The piston ring may be constructed of a material that when subjected to heat causes a shape of the meanderings to change, thereby enabling the piston ring to expand in an axial direction of the piston, between the edges of the groove.

A linear reciprocating engine 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 within the cylinder. The engine may further include a first piston rod portion extending from a first face of the double-faced piston through the first combustion chamber, and a second piston rod portion extending from a second face of the piston through the second combustion chamber. Passageways in the piston rod portions may be configured to communicate gases between the combustion chamber and a location outside the cylinder and configured to prevent gases from being exchanged between the cylinder and a location outside the cylinder via a path that crosses both face of the piston.

An internal combustion engine for use in land, aerial and water vehicles and various kinds of machinery. A first version of the engine has a cylinder with the inlet channel of compressed air and the outlet exhaust channel situated in the middle of it. In the cylinder head as well as in the partition there are the fuel injector, the water injector and the ignition element. In the middle of the partition the slide bearing is embedded, through which the tappet rod goes. The upper end of this rod is attached to the bilateral piston, whereas its lower end is connected to the connecting rod. The water injectors are powered from the water container through the heating element and the metering device. A second version the engine has a plurality of cylinders in a radial orientation.

A linear reciprocating engine may include a cylinder having first and second combustion chambers at opposing ends, first and second cylinder heads at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted within the cylinder. The engine may further include an exhaust port located in a peripheral cylinder wall and at least one combustion gas inlet in a location other than the peripheral cylinder wall. The combustion gas inlet and the exhaust port may be configured to cooperate such that combustion gases introduced through the inlet are evacuated from the cylinder through the exhaust port. The double-faced piston may have an axial length from one face to an opposite face of the piston less than or equal to of a distance from at least one of the first cylinder head and the second cylinder head to the exhaust port.

A linear reciprocating engine 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 within the cylinder. The engine may further include a first piston rod portion extending from a first face of the double-faced piston through the first combustion chamber, and a second piston rod portion extending from a second face of the piston through the second combustion chamber. Passageways in the piston rod portions may be configured to communicate gases between the combustion chamber and a location outside the cylinder and configured to prevent gases from being exchanged between the cylinder and a location outside the cylinder via a path that crosses both face of the piston.

An internal combustion engine comprises an engine block defining a cylinder having a longitudinal axis A. A piston is arranged slidably within the cylinder and an impeller is arranged at one end of the cylinder. The impeller is rotatably mounted on a shaft, which extends out of the cylinder and which is driven in rotation by rotation of the impeller. The engine further comprises an anti-rotation formation to prevent the piston rotating about a longitudinal axis of the cylinder and a swirl-inducing vane arranged on the face of the piston which faces the end of the cylinder at which the impeller is arranged. Combustion gas generated by combustion of a fuel in the cylinder between the piston and the impeller is caused to swirl by reaction with the swirl-inducing vane and the swirling combustion gases, in turn, cause the impeller to rotate.

An engine may include a cylinder having a first combustion chamber at one end thereof and a second combustion chamber at an opposing end thereof, first and second cylinder heads at an end of the first combustion chamber and the second combustion chamber, respectively, and a double-faced piston slidably mounted within the cylinder. The piston may be configured to move in a first stroke from the first end to the second end of the cylinder. The piston and the cylinder may be configured such that the first stroke includes an expansion stroke portion during which chemical energy from combustion in the first combustion chamber is converted into mechanical power of the piston, and a momentum stroke portion during which the piston continues to move to the second end of the cylinder and gases are exchanged between the first combustion chamber and a location outside the cylinder.