A piston arrangement for a clean combustion engine, such as a hydrogen engine. The piston arrangement comprises a piston configured for reciprocal movement inside a cylinder having a cylinder wall, the piston having a piston head configured to face a first compartment with pressurized gas, a sealing arrangement comprising at least one sealing ring configured to be arranged to seal the piston to the cylinder wall and separating the first compartment from a second compartment, and a water channel extending from an interior of the piston to the sealing ring to provide water for lubricating the sealing ring. The piston head comprises a pumping element configured to be arranged to pressurize the water in the water channel by pressurised gas in the first compartment.

A piston arrangement for a clean combustion engine, such as a hydrogen engine. The piston arrangement comprises a piston configured for reciprocal movement inside a cylinder having a cylinder wall, the piston having a piston head configured to face a first compartment with pressurized gas, a sealing arrangement comprising at least one sealing ring configured to be arranged to seal the piston to the cylinder wall and separating the first compartment from a second compartment, and a water channel extending from an interior of the piston to the sealing ring to provide water for lubricating the sealing ring. The piston head comprises a pumping element configured to be arranged to pressurize the water in the water channel by pressurised gas in the first compartment.

A cylinder actuator includes a body assembly and a piston assembly. The body assembly includes a first cylinder nested concentrically within a second cylinder. The piston assembly slides linearly within the first and second cylinders. The piston assembly includes a first piston assembly end and a second piston assembly end. The first piston assembly end includes first and second pistons. The first piston moves within the first cylinder. The second piston moves within the second cylinder. The piston assembly includes first and second piston rods. The first piston rod extends from the first piston through a first end of the first cylinder. The second piston rod extends from the second piston through a first end of the second cylinder. The piston rods are joined at the second end of the piston rod assembly located outside of the first and second cylinders.

In an opposed piston engine, an inlet piston crankshaft axis and an exhaust piston crankshaft axis both extend parallel to a central cylinder plane extending through a centerpoint of a cylinder of the engine and along a central axis of the cylinder. The inlet piston crankshaft axis and the exhaust piston crankshaft axis are both offset from the central cylinder plane. The inlet piston and the exhaust piston linked to the inlet piston crankshaft and the exhaust piston crankshaft are arranged so that the inlet piston closes an inlet port as the inlet piston moves from its bottom dead center toward its top dead center at substantially a same time as the exhaust piston closes the exhaust port as the exhaust piston moves from its bottom dead center toward its top dead center.

In an opposed piston engine, an inlet piston crankshaft axis and an exhaust piston crankshaft axis both ex tend parallel to a central cylinder plane extending through a centerpoint of a cylinder of the engine and along a central axis of the cylinder. The inlet piston crankshaft axis and the exhaust piston crankshaft axis are both offset from the central cylinder plane. The inlet piston and the exhaust piston linked to the inlet piston crankshaft and the exhaust piston crankshaft are arranged so that the inlet piston closes an inlet port as the inlet piston moves from its bottom dead center toward its top dead center at substantially a same time as the exhaust piston closes the exhaust port as the exhaust piston moves from its bottom dead center toward its top dead center.

A Polygon Oscillating Piston Engine having multiple pistons on one of two oscillating disks. Each piston moves in a straight line along one of the sides of a polygon within a cylindrical chamber, while the oscillating disks move in an arc about a central shaft. The difference in the straight motion of the piston and angular motion of the oscillating disk is accommodated by a slip sleeve within the piston that slides on a peg or bar mounted to each disk. The engine can be configured to operate as an internal combustion engine that uses diesel fuel, gasoline, or natural gas, or it can be configured as an expander to convert high pressure high temperature gas to rotary power. This engines compact design results in a high power-to-weight ratio.

A Polygon Oscillating Piston Engine having multiple pistons on one of two oscillating disks. Each piston moves in a straight line along one of the sides of a polygon within a cylindrical chamber, while the oscillating disks move in an arc about a central shaft. The difference in the straight motion of the piston and angular motion of the oscillating disk is accommodated by a slip sleeve within the piston that slides on a peg or bar mounted to each disk. The engine can be configured to operate as an internal combustion engine that uses diesel fuel, gasoline, or natural gas, or it can be configured as an expander to convert high pressure high temperature gas to rotary power. This engines compact design results in a high power-to-weight ratio.

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 using a two stroke cycle includes a pair of opposing cylinder units, each of which are located on opposing sides of a crankcase. In each cylinder unit is a cylinder with a piston disposed in the cylinder. Each piston is coupled to a piston rod that is aligned along an axis that passes through the center of each cylinder bore. The piston rods pass through the crankcase wall into the crankcase chamber, and are further coupled to a yoke. Each cylinder unit has an intake channel from the crankcase chamber to a cylinder intake port in the cylinder. As the piston traverses its upstroke in its cylinder, it creates a vacuum under the piston. At the top of its stroke a piston intake port becomes aligned with the cylinder intake port, allow fuel to be drawn into the cylinder under the piston. As a result, a continuous vacuum is experienced in the crankcase without the need for mechanical valving arrangements.

An opposed piston engine includes an engine housing, at least one cylinder housing coupled to the engine housing, and at least one cylinder supported by the engine housing and by the cylinder housing along an exterior of the engine housing.