This invention has two main embodiments. An opposed piston 2-stroke axial engine and a 4-stroke axial engine. The opposed piston two stroke also offers an option of a novel cylinder deactivation design. Both, two stroke and four stroke engines share novel systems for coupling piston reciprocation to shaft rotation, piston and piston ring lubricant distribution, and provision for reacting out piston side load with minimum mechanical friction

The invention relates to a method (100) for controlling a powertrain system (10) of a vehicle (1) during gear upshifting, said powertrain system comprising: an internal combustion engine system (11) comprising an internal combustion engine (12) configured to output a rotational speed (W1) via an engine output shaft (8); a transmission arrangement (14) having a number of gear stages to obtain a set of gears, the transmission arrangement being operatively connected to the internal combustion engine via a transmission input shaft (64) and further having a transmission output shaft (24) for providing a rotational speed to one or more drive wheels (26) of the vehicle; the method comprising the steps of: operating (110) the engine in a four-stroke operation to provide engine rotational speed output via the engine output shaft; receiving (120) an indication of an intended upshifting from a gear of the set of gears to a higher gear of the sets of gears; reducing (130) the rotational speed of the engine output shaft by adjusting the operation of the engine from the four-stroke operation to a two-stroke braking operation; and, when said engine is in the two-stroke braking operation, performing (140) the intended upshifting from said gear of the set of gears to said higher gear of the sets of gears.

An internal combustion engine may be used to compress natural gas for vehicle fuel. The engine may contain a plurality of gas compression cylinders, at least one standard combustion cylinder to drive the compression cylinders, and a common crankshaft in a crankcase coupling the compression cylinders and the at least one standard combustion cylinder. Some combustible gas being compressed may leak past the piston rings of the compression cylinders into the engine crankcase posing a safety concern. This invention eliminates this concern by actively flushing the crankcase at a higher rate than normal.

In an exemplary embodiment, an internal combustion engine, in which a valve is opened and closed when a piston reciprocates in a cylinder, has a configuration to perform repeatedly the following combined strokes: an intake stroke.fwdarw.a compression stroke.fwdarw.a combustion stroke.fwdarw.an exhaust stroke in a four-cycle internal combustion engine are combined with an intake and compression stroke.fwdarw.a combustion and exhaust stroke in a two-cycle internal combustion engine. The internal combustion engine can reduce pumping loss in a six-cycle internal combustion engine and increase the output.

An internal combustion engine includes a hollow cylinder, a piston within the hollow cylinder, and a cylinder head. A base valve assembly at a base of the hollow cylinder permits or restricts fluid flow from an intake manifold into a sub-chamber below the piston. The piston includes at least one intake port connecting a combustion chamber above the piston with the sub-chamber, and a transfer valve that opens and closes the at least one intake port. When the transfer valve opens the at least one intake port, fluid is permitted to flow from the sub-chamber to the combustion chamber. The internal combustion engine operates according to a four-stroke piston cycle, wherein multiple intake stages are provided. The intake stages may include intake of air into the sub-chamber during a compression stroke, transfer of air from the sub-chamber to the combustion chamber during a power stroke, intake of air-fuel mixture into the sub-chamber during an exhaust stroke, and transfer of air-fuel mixture from the sub-chamber to the combustion chamber during an intake stroke.

A method of injection of liquid or gaseous ammonia fuel into a reciprocating engine that includes at least two cylinders, each cylinder including a piston that moves reciprocally within that cylinder, each cylinder having a head location at one end located opposite to a compression end of the piston and defining a combustion chamber therebetween, the cylinder including at least one inlet valve through which combustion gases are fed into the combustion chamber and at least one exhaust valve through which spent combustion gases egress the combustion chamber, the piston moving the cylinder in a cycle between top dead center where the piston is located closest to the head location and bottom dead center where the piston is located furthest from the head location, and including at least one fuel injector located at or in the head location, and wherein the method comprises: injecting the ammonia fuel into the combustion chamber of each cylinder as at least one fuel jet with a timing of: after the at least one exhaust valve of the respective cylinder is substantially closed; and before the respective piston moves to at most 35 degrees, preferably at most 45 degrees, prior to top dead centre.

An internal combustion engine may include a first piston reciprocatingly disposed in a first cylinder, and a second piston reciprocatingly disposed in a second cylinder. A crankshaft may be coupled with the first piston and the second piston for rotational motion associated with reciprocating movement of at least one of the first piston and the second piston. A combustion chamber may be fluidly coupled with the first cylinder and the second cylinder. An ignition source may be at least partially disposed within the combustion chamber. An intake valve may provide selective fluid communication between an intake system and the combustion chamber, and an exhaust valve may provide selective fluid communication between an exhaust system and the combustion chamber.

The present invention relates to a two strokes per cycle Scotch Yoke engine that completes four power strokes per revolution per pair of pistons/cylinders by using both sides of each piston as a combustion chamber. This doubles the power to weight ratio over previous scotch yoke engines and quadruples the power to weight ratio over conventional 4 stroke cycle engines. The present invention is capable of operating in and withstanding the forces of either deflagration (subsonic) and pulse detonation (supersonic) cycles, and is capable of homogeneous charge compression ignition. The present invention can also be an internal/external combustion gas/steam hybrid. The present invention can operate under constant volume or constant pressure cycles as well as most thermal cycles of operation (EG the Otto and Diesel cycle). The present invention works best when using a modified Humphrey cycle to achieve homogeneous charge compression ignition pulse detonation engine using constant volume combustion.

An internal combustion engine may include a first piston reciprocatingly disposed in a first cylinder, a combustion chamber fluidly coupled with the first cylinder, and an ignition source at least partially disposed within the combustion chamber. An intake valve may provide selective fluid communication between an intake system and the combustion chamber, and an exhaust valve may provide selective fluid communication between an exhaust system and the combustion chamber. A second piston may be reciprocatingly disposed within a second cylinder. An inlet associated with the second cylinder may be fluidly coupled with the intake system, and an outlet may be fluidly coupled with one or more of the first cylinder and the combustion chamber. A crankshaft may be coupled with the first piston and the second piston for rotational motion associated with reciprocating movement of the first piston and the second piston.

An internal combustion engine may include a first piston reciprocatingly disposed in a first cylinder, a combustion chamber fluidly coupled with the first cylinder, and an ignition source at least partially disposed within the combustion chamber. An intake valve may provide selective fluid communication between an intake system and the combustion chamber, an exhaust valve may provide selective fluid communication between an exhaust system and the combustion chamber. A second piston may be reciprocatingly disposed within a second cylinder, configured to draw a fluid into the second cylinder via a fluid inlet, and expel the fluid via a fluid outlet. A pressure accumulator may receive the fluid from the second cylinder and provide a reservoir of pressurized fluid. A crankshaft may be coupled with the first piston and the second piston for rotational motion associated with reciprocating movement of the first piston and the second piston.