A control device of an engine including a cylinder, a piston, a cylinder head, and a combustion chamber is provided, which includes intake and exhaust ports, a swirl control valve provided in an intake passage connected to the intake port, a fuel injection valve attached to the cylinder head to be oriented into the center of the combustion chamber in a plan view thereof, and having first and second nozzle ports, and a control unit. The control unit includes a processor configured to execute a swirl opening controlling module to output the control signal to the swirl control valve to have a given opening at which a swirl ratio inside the combustion chamber becomes 2 or above, and a fuel injection timing controlling module to output the control signal to the fuel injector to inject fuel at a given timing at which the swirl ratio becomes 2 or above.

free-piston engine power plant incorporating a first combustion cylinder having a first combustion piston, a fluid expander having an expansion cylinder with an expander piston therein, the expander piston reciprocating in unison with the first combustion piston, a bottoming cycle having a working fluid and a heat exchanger.

A free-piston (FP) engine is a type of internal combustion engine with no crankshaft, so that its piston trajectory is no longer constrained by the mechanical linkage. FP engines have a high potential in terms of energy saving given their simple structure, high modularity and high efficiency, among other attributes. One of the technical barriers that affect FP engine technology is a lack of precise piston trajectory control. For example, the presence of a transient period after a single combustion event can prevent the engine from continuous firing. The present subject matter provides a control scheme that can utilize a reference and control signal shifting technique to modify the tracking error and the control signal to reduce the transient period.

An object of the present invention is to provide a method and a system for implementing the method so as to alleviate the disadvantages of a reciprocating combustion engine and gas turbine when generating power. The invention is based on the idea of arranging a multifunction valve inside a combustion chamber to create more favourable favorable conditions for combustion process. The multifunction valve may act as an output valve, but it can also provide additional final compression to contents of the compression chamber and it may even capture part of energy released in a combustion process.

Various embodiments of the present invention are directed toward a linear generator, comprising: a cylinder having a cylinder wall and a pair of ends, the cylinder including a reaction section disposed in a center portion of the cylinder; a pair of opposed piston assemblies adapted to move linearly within the cylinder, each piston assembly disposed on one side of the reaction section opposite the other piston assembly, each piston assembly including a spring rod and a piston comprising a solid front section adjacent the reaction section and a gas section; and a pair of linear electromagnetic machines adapted to directly convert kinetic energy of the piston assembly into electrical energy, and adapted to directly convert electrical energy into kinetic energy of the piston assembly for providing compression work during the compression stroke.

Various embodiments of the present disclosure are directed towards free-piston combustion engines. As described herein, a method and system are provided for displacing a free-piston assembly to achieve a desired engine performance by repeatedly determining position-force trajectories over the course of a propagation path and effecting the displacement of the free-piston assembly based, at least in part, on the position-force trajectory. In a dual-piston assembly free-piston engine, synchronization of the two piston assemblies is provided.

Various embodiments of the present disclosure are directed towards free-piston combustion engines. As described herein, a method and system are provided for displacing a free-piston assembly to achieve a desired engine performance by repeatedly determining position-force trajectories over the course of a propagation path and effecting the displacement of the free-piston assembly based, at least in part, on the position-force trajectory. In a dual-piston assembly free-piston engine, synchronization of the two piston assemblies is provided.

Various embodiments of the present invention are directed toward a linear combustion engine, comprising: a cylinder having a cylinder wall and a pair of ends, the cylinder including a combustion section disposed in a center portion of the cylinder; a pair of opposed piston assemblies adapted to move linearly within the cylinder, each piston assembly disposed on one side of the combustion section opposite the other piston assembly, each piston assembly including a spring rod and a piston comprising a solid front section adjacent the combustion section and a gas section; and a pair of linear electromagnetic machines adapted to directly convert kinetic energy of the piston assembly into electrical energy, and adapted to directly convert electrical energy into kinetic energy of the piston assembly for providing compression work during the compression stroke.

A modular motor is disclosed that includes a piston/harmonic drive assembly that is axially cycled. The piston/harmonic drive assembly is coupled to a ball transfer arrangement that converts the axial motion into rotary motion to rotate a rotor that can be used to rotate a drill bit.

An air motor assembly includes an exhaust block with an exhaust port that conveys exhaust air into an exhaust manifold. The exhaust port includes an expansion chamber that creates a pressure drop in the exhaust gas, thereby decreasing the temperature of the exhaust gas. The expansion chamber is defined between a first wall that is tangential to the air motor cylinder and a second wall that is transverse to an axis of the exhaust port. Poppet valves control actuation of a shuttle. The poppet valves are disposed on the exterior of the air motor assembly and are thermally insulated from the air motor assembly.