Abstract: A thermodynamic apparatus, such as a Stirling engine or a Vuilleumier heat pump, has a heat exchanger in which energy is exchanged between a working fluid and an exhaust gas stream. On top of the cylinder of the thermodynamic apparatus is a dome-shaped section. By incorporating the heat exchanger within the dome, the flow paths can be simplified, the number of separate components reduced, and overall weight reduced. Flow passages for the working fluid are embedded in the dome. Channels for the exhaust gases are formed in an outer surface. The passages and the channels are helically arranged, one clockwise and one counter clockwise. The dome can be cast with a core for the casting fabricated via three-dimensional printing. In some embodiments, the dome is made of fiber-reinforced material.

Abstract: The disclosure relates to an internal combustion engine (1) with at least one double cylinder (2), in which two inner pistons (6) and two outer pistons (7) are arranged such that they reciprocate in the double cylinder (2) by at least one respective inner connecting rod (8) or a respective first outer connecting rod (11a) and a respective second outer connecting rod (11b) with the aid of a crankshaft (4). The present disclosure provides an internal combustion engine (1) in which the outer connecting rods do not pivot. The two first outer connecting rods (11a) of the two outer pistons (7) are coaxial and integrally formed; and the two second outer connecting rods (11b) are coaxial and integrally formed.

Abstract: A thermodynamic apparatus, such as a Stirling engine or a Vuilleumier heat pump, has a heat exchanger in which energy is exchanged between a working fluid and an exhaust gas stream. On top of the cylinder of the thermodynamic apparatus is a dome-shaped section. By incorporating the heat exchanger within the dome, the flow paths can be simplified, the number of separate components reduced, and overall weight reduced. Flow passages for the working fluid are embedded in the dome. Channels for the exhaust gases are formed in an outer surface. The passages and the channels are helically arranged, one clockwise and one counter clockwise. The dome can be cast with a core for the casting fabricated via three-dimensional printing. In some embodiments, the dome is made of fiber-reinforced material.

Abstract: An internal combustion engine includes a crankshaft having a first web portion defining an inner opening and defining an undercut proximate the inner opening, a second web portion defining an inner opening and defining an undercut proximate the inner opening and an inner bearing portion that engages with the inner opening of the first web portion and with the inner opening of the second web portion. First and second pushrods each have a piston end and a crankshaft end. The crankshaft ends of the first and second pushrods each have a concave surface placed over different portions of the inner bearing portion between the first and second web portions, and each further have shoulders adjacent their respective concave surface that engage with the undercuts of the first and second web portions.

Abstract: Reciprocating motion can be converted to rotary motion through a crankshaft and a connecting rod. In a connecting rod that is primarily in compression, two opposing connecting rods can be coupled to a single journal. Two bearing shell portions are placed over the journal with a pushrod placed over each bearing shell portion. The pushrods are normally in compression. To overcome the potentiality of the pushrods briefly being in tension, retainers can be coupled to the pushrods. Because both pushrods are coupled in-line, the width of the journal that can accommodate these pushrods is shorter than for a journal on which the two pushrods are side by side. The crankshaft can be shorter, stronger, and lighter weight.

Abstract: Two-stroke engines are particularly prone to piston scuffing due to insufficient oil at some operating conditions. A system and method to precisely deliver oil is disclosed. An oil reservoir groove is formed in the piston with an oil reservoir ring welded to the surface of the piston. A cavity behind the ring forms an oil reservoir. The ring has an inlet gap. The cylinder wall has an oil injector installed therein which sprays oil into the inlet gap when the inlet gap is proximate the oil injector tip. An electronic control unit commands the quantity of oil to provide to the oil reservoir, with the quantity and timing of the injections based on the operating conditions of the engine.

Abstract: Reciprocating motion can be converted to rotary motion through a crankshaft and a connecting rod. In a connecting rod that is primarily in tension, two opposing connecting rods can be coupled to a single journal. Two bearing caps are placed over the journal, the bearing caps having fingers that extend away from the bearing cap with the fingers of the two bearing caps being enmeshed. Fingers of each bearing cap are coupled to the connecting rods. The resulting joint is compact and lighter weight with a shorter journal than prior joints.

Abstract: A combustion chamber of an internal combustion engine has primary intake ports located a first distance from the crankshaft and primary intake ports located a second distance from the crankshaft. One or more unidirectional valves, such as reed valves, are place in an intake duct upstream of the primary intake ports. The valves prevent backflow from the cylinder into the intake when the pressure in the cylinder exceeds that of the intake. The backflow into the intake is reduced by having valves in the intake; therefore scavenging efficiency is improved. Furthermore, the asymmetry between the intake and exhaust port timing may be reduced by providing such valves. Additionally, the total intake port area can be increased with two sets of intake ports and valves disposed in the primary ports, thereby improving the volumetric efficiency in spite of the pressure drop presented by the valves.

Abstract: An opposed-piston, opposed-cylinder OPOC engine is disclosed in which the central axis of the two cylinders is collinear. In four-stroke engines, this is possible with a built up crankshaft. Disclosed are connecting rod configurations that are suitable for a two-stroke engine that can be assembled to a unitary crankshaft, including both pullrods in tension and pushrods in compression. The configuration includes pistons arranged symmetrically, but with offset timing of the intake and exhaust pistons. The offset timing leads to a slight imbalance which can be partially overcome by having the center of gravity of the crankshaft offset from the axis of rotation.

Abstract: A combustion chamber of an internal combustion engine has primary intake ports located a first distance from the crankshaft and primary intake ports located a second distance from the crankshaft. One or more unidirectional valves, such as reed valves, are place in an intake duct upstream of the primary intake ports. The valves prevent backflow from the cylinder into the intake when the pressure in the cylinder exceeds that of the intake. The backflow into the intake is reduced by having valves in the intake; therefore scavenging efficiency is improved. Furthermore, the asymmetry between the intake and exhaust port timing may be reduced by providing such valves. Additionally, the total intake port area can be increased with two sets of intake ports and valves disposed in the primary ports, thereby improving the volumetric efficiency in spite of the pressure drop presented by the valves.

Abstract: Reciprocating motion can be converted to rotary motion through a crankshaft and a connecting rod. In a connecting rod that is primarily in compression, two opposing connecting rods can be coupled to a single journal. Two bearing shell portions are placed over the journal with a pushrod placed over each bearing shell portion. The pushrods are normally in compression. To overcome the potentiality of the pushrods briefly being in tension, retainers can be coupled to the pushrods. Because both pushrods are coupled in-line, the width of the journal that can accommodate these pushrods is shorter than for a journal on which the two pushrods are side by side. The crankshaft can be shorter, stronger, and lighter weight.

Abstract: Reciprocating motion can be converted to rotary motion through a crankshaft and a connecting rod. In a connecting rod that is primarily in tension, two opposing connecting rods can be coupled to a single journal. Two bearing caps are placed over the journal, the bearing caps having fingers that extend away from the bearing cap with the fingers of the two bearing caps being enmeshed. Fingers of each bearing cap are coupled to the connecting rods. The resulting joint is compact and lighter weight with a shorter journal than prior joints.

Abstract: An opposed-piston, opposed-cylinder OPOC engine is disclosed in which the central axis of the two cylinders is collinear. In four-stroke engines, this is possible with a built up crankshaft. Disclosed are connecting rod configurations that are suitable for a two-stroke engine that can be assembled to a unitary crankshaft, including both pullrods in tension and pushrods in compression. The configuration includes pistons arranged symmetrically, but with offset timing of the intake and exhaust pistons. The offset timing leads to a slight imbalance which can partially overcome by having the center of gravity of the crankshaft offset from the axis of rotation.

Abstract: In an opposed-piston, opposed-cylinder engine, a high degree of swirl is developed during the scavenging process and persists into the combustion stroke. The engine has one or more injectors at the periphery of the combustion chamber injecting fuel into the air at the point in which the air has the highest tangential velocity. The swirling air causes the jets to be pushed together and some of the jets to be pushed into the cylinder wall. According to an embodiment of the disclosure, the exhaust piston has a raised portion and a recessed portion. Protuberances extending inwardly are provided on the raised portion of the exhaust piston to dampen the swirl.

Abstract: An electrical generator utilizing two internal combustion engine having an expanded range of power output is disclosed. A primary internal combustion engine is coupled to the magnet rotor assembly. The primary engine is operated solely in a lower power range. A secondary engine, coupled to a coil assembly is locked in place in such lower power range to make the coil assembly stationary. In a higher power range, that overlaps the lower power range, the secondary engine is unlocked and operated to rotate in a counter-rotating direction with respect to the first engine. The secondary engine can be started by operating the generator (consisting of the magnet rotor assembly and the coil assembly) as a motor by appropriate application of current.

Abstract: A two-stroke internal combustion engine is disclosed having opposed cylinders, each cylinder having a pair of opposed pistons, with all the pistons connected to a common central crankshaft. The inboard pistons of each cylinder are connected to the crankshaft with pushrods and the outboard pistons are connected to the crankshaft with pullrods. Each opposed cylinder further comprises an integrated scavenge pump for providing positive intake pressure. This configuration results in a compact engine with a very low profile, in which the free mass forces can be substantially balanced. The engine configuration also allows for asymmetrical timing of the intake and exhaust ports through angular positioning of the journals on the crankshaft.

Abstract: A two-stroke internal combustion engine is disclosed having opposed cylinders, each cylinder having a pair of opposed pistons, with all the pistons connected to a common central crankshaft. The inboard pistons of each cylinder are connected to the crankshaft with pushrods and the outboard pistons are connected to the crankshaft with pullrods. Each opposed cylinder further comprises an integrated scavenge pump for providing positive intake pressure. This configuration results in a compact engine with a very low profile, in which the free mass forces can be substantially balanced. The engine configuration also allows for asymmetrical timing of the intake and exhaust ports through angular positioning of the journals on the crankshaft.

Abstract: An internal combustion engine is disclosed having opposed cylinders, each cylinder having a pair of opposed pistons. All the pistons may be connected to a common central crankshaft. The inboard pistons of each cylinder may be connected to a common joint on the crankshaft with pushrods and the outboard pistons may be connected to a common joint on the crankshaft with pullrods. Each opposed cylinder may include an integrated scavenge pump for providing positive intake pressure. The engine configuration also allows for asymmetrical timing of the intake and exhaust ports through angular positioning of the journals on the crankshaft.

Abstract: A two-stroke internal combustion engine is disclosed having opposed cylinders, each cylinder having a pair of opposed pistons, with all the pistons connected to a common central crankshaft. The inboard pistons of each cylinder are connected to the crankshaft with pushrods and the outboard pistons are connected to the crankshaft with pullrods. Each opposed cylinder further comprises an integrated scavenge pump for providing positive intake pressure. This configuration results in a compact engine with a very low profile, in which the free mass forces can be substantially balanced. The engine configuration also allows for asymmetrical timing of the intake and exhaust ports through angular positioning of the journals on the crankshaft.