Abstract: A combustion chamber for an opposed-piston engine is defined between a pair of pistons disposed for opposing reciprocal movement in a cylinder. The combustion chamber is formed between crowns of the pistons and has a radius that decreases from the longitudinal axis of the cylinder. Each crown includes a periphery, a bowl within the periphery defining a concave surface with a first portion curving inwardly toward the interior of the piston and a second portion curving outwardly from the interior, and a convex surface within the periphery curving outwardly and meeting the second portion of the concave surface to form a ridge. Each ridge has a height that decreases with the distance from a longitudinal axis.

Abstract: A cylinder for an opposed-piston engine is equipped with a cylinder bore that provides solid lubrication of bore/piston surface interfaces in top ring reversal zones of the cylinder bore.

Abstract: A cylinder cooling construction includes a cylinder liner with a sidewall, exhaust and intake ports opening through the sidewall, a bore, and a plurality of feed channels that are formed with and extend along the sidewall from a central band of the cylinder toward the exhaust and intake ports. A sleeve covering the sidewall includes a plurality of impingement jet ports that are arranged in at least one sequence extending around the central band and that are in liquid communication with the plurality of feed channels. An annular member disposed between the liner and the sleeve reinforces the central band. The sleeve further includes an inside surface with spaced-apart annular recesses that with the sidewall define liquid coolant reservoirs in the vicinity of the ports that are in liquid communication with the feed channels.

Abstract: In an opposed piston, compression ignition engine two crankshafts are single-side mounted with respect to a row of cylinders, which is to say that the crankshafts are mounted so that their axes of rotation lie in a plane that is spaced apart from and parallel to a plane in which the axes of the cylinders lie. Each piston of the engine is coupled to one of the crankshafts by a single linkage guided by a crosshead. The piston has a piston rod affixed at one end to the piston. The other end of the piston rod is affixed to the crosshead pin. One end of a connecting rod swings on the pin and the other end is coupled to a throw on a crankshaft. Each crosshead is constrained to reciprocate between fixed guides, in alignment with the piston rod to which it is coupled.

Abstract: A two-stroke cycle, turbo-driven, opposed-piston engine with one or more ported cylinders and uniflow scavenging has no supercharger. The engine includes a high pressure EGR loop and a pump in the EGR loop to boost the pressure of the recirculated exhaust products.

Abstract: In an opposed piston, compression ignition engine two crankshafts are single-side mounted with respect to a row of cylinders, which is to say that the crankshafts are mounted so that their axes of rotation lie in a plane that is spaced apart from and parallel to a plane in which the axes of the cylinders lie. Each piston of the engine is coupled to one of the crankshafts by a single linkage guided by a crosshead. The piston has a piston rod affixed at one end to the piston. The other end of the piston rod is affixed to the crosshead pin. One end of a connecting rod swings on the pin and the other end is coupled to a throw on a crankshaft. Each crosshead is constrained to reciprocate between fixed guides, in alignment with the piston rod to which it is coupled.

Abstract: A piston construction with an end surface is equipped with a pattern of insulating cavities embedded in an upper end of the piston, between the end surface and interior portions of the piston that are cooled by circulating liquid coolant.

Abstract: In an opposed-piston engine, two or more fuel injectors are mounted to a cylinder for direct side injection into the cylinder. The injectors are controlled so as to inject either a single fuel pulse or a plurality of fuel pulses per cycle of engine operation in order to initiate combustion during varying engine speeds and operating conditions.

Abstract: A cylinder cooling construction includes a cylinder liner with a sidewall, exhaust and intake ports opening through the sidewall, a bore, and a plurality of feed channels that are formed with and extend along the sidewall from a central band of the cylinder toward the exhaust and intake ports. A sleeve covering the sidewall includes a plurality of impingement jet ports that are arranged in at least one sequence extending around the central band and that are in liquid communication with the plurality of feed channels. An annular member disposed between the liner and the sleeve reinforces the central band. The sleeve further includes an inside surface with spaced-apart annular recesses that with the sidewall define liquid coolant reservoirs in the vicinity of the ports that are in liquid communication with the feed channels.

Abstract: A dual-crankshaft, opposed-piston, internal combustion engine includes one or more ported cylinders. Each cylinder has exhaust and intake ports, and the cylinders are juxtaposed and oriented with exhaust and intake ports mutually aligned. The crankshafts are rotatably mounted at respective exhaust and intake ends of the cylinders and are coupled by a multi-gear train. A pair of pistons is disposed for opposed sliding movement in the bore of each cylinder. All of the pistons controlling the exhaust ports are coupled by connecting rods to the crankshaft mounted near at the exhaust ends of the cylinders, and all of the pistons controlling the intake ports are coupled by connecting rods to the crankshaft mounted near at the intake ends of the cylinders. The crankshafts are connected by a timing belt operative to change the rotational timing between the crankshafts. The gear train support structure is stiffened to suppress gear train vibration.

Abstract: In a two-cycle, opposed-piston internal combustion engine, opposed pistons disposed in a cylinder are coupled to a pair of side-mounted crankshafts by connecting rods that are subject to substantially tensile forces acting between the pistons and the crankshafts. This geometry reduces or eliminates side forces between the pistons and the bore of the cylinder. The cylinder and the pistons are independently cooled to reduce cylindrical deformation caused by thermal expansion during engine operation.

Abstract: An internal combustion engine including a cylinder with bore and a piston disposed to reciprocate in the bore is operated by moving the piston in the bore between top and bottom dead center positions and applying lubricant to a portion of the piston that protrudes from the bore. Lubricant is wiped from the piston as the piston travels into the bore toward its top dead center position.

Abstract: An opposed piston engine includes at least one cylinder with inlet and exhaust ports and opposed pistons disposed in the cylinder for reciprocating opposed motion toward and away from each other. An auxiliary system pumps liquid coolant separately to the cylinder and pistons. Another auxiliary system controls the flow of intake and exhaust gas in the engine.

Abstract: In a two-stroke opposed-piston engine, a ported cylinder with a pair of opposed pistons is equipped with an engine brake including an engine braking valve that can be opened to release air from the cylinder as the pistons cycle between BDC and TDC positions.

Abstract: An opposed piston engine includes at least one cylinder with a bore surface and longitudinally-spaced exhaust and intake ports that open through the sidewall of the cylinder. A pair of opposed pistons is disposed in the cylinder for sliding movement along the bore surface. An oil-retaining surface texture pattern in an interface between the pistons and the bore surface extends in a longitudinal direction of the cylinder, aligned with bridges of at least one port. The surface texture pattern includes a plurality of separate recesses on an outside surface of a skirt of each piston. Alternatively, or in addition, the surface texture pattern includes a plurality of separate recesses extending in a longitudinal direction of the cylinder, aligned with bridges of at least one port.

Abstract: In a two-cycle, opposed-piston internal combustion engine, opposed pistons disposed in a cylinder are coupled to a pair of side-mounted crankshafts by connecting rods that are subject to substantially tensile forces acting between the pistons and the crankshafts. This geometry reduces or eliminates side forces between the pistons and the bore of the cylinder. The cylinder and the pistons are independently cooled to reduce cylindrical deformation caused by thermal expansion during engine operation.

Abstract: In a two-stroke opposed-piston engine, a ported cylinder with a pair of opposed pistons is equipped with a decompression port including a valve and a passage with an opening through the cylinder wall that is located between the cylinder's intake and exhaust ports. The decompression port enables release of compressed air from the cylinder after the intake and exhaust ports are closed. The valve is opened to permit compressed air to be released from the cylinder through the passage, and closed to retain compressed air in the cylinder. Engine braking is supported by release of compressed air through the decompression port into an exhaust channel when the pistons are at or near top dead center positions as the cycle transitions from the intake/compression stroke to the power/exhaust stroke. Compression release from the cylinder after intake and exhaust port closure can also support other engine operations.

Abstract: An opposed-piston internal combustion engine with one or more ported cylinders and uniflow scavenging includes fuel injectors supported at compound angles with respect to the cylinders in order to directly inject spray patterns of fuel in opposing directions through the side walls of the cylinders.

Abstract: A combustion chamber for an opposed-piston engine includes a squish zone defined between circumferential peripheral areas of opposing end surfaces of the pistons, a cavity defined by one or more bowls in the end surfaces, and at least one injection port that extends radially through the squish zone into the cavity. The cavity has a cross-sectional shape that imposes a tumbling motion on air flowing from the squish zone into the cavity. Opposing spray patterns of fuel are injected into the combustion chamber. In some aspects, the opposing spray patterns are injected along a major axis of the combustion chamber.

Abstract: A piston construction for an opposed-piston engine accommodates contoured end surfaces of the piston crowns and articulation of the pistons with piston rods. The shape of each piston crown includes a bowl with an adjoining ridge that protrudes axially of the piston. A cooling construction for the piston includes an outer gallery running around the inner surface of the piston sidewall in the vicinity of the crown. The outer gallery girds and is in fluid communication with a central gallery that abuts the deepest part of the bowl. The outer gallery has an asymmetric profile that rises under the ridge and that slants upwardly under a peripheral portion of the bowl. A mechanism for coupling the piston to a piston rod includes a biaxial slipper bearing.