An engine includes a cylinder block including a cylinder hole, a crank shaft as an offset crank, and a connecting rod that connects the piston and the crank shaft. An inclined surface is provided on an entire circumference of a crank-shaft-side opening edge of one end of the cylinder hole. When viewed in the axial direction of the crank shaft, a boundary line between the inclined surface and the cylinder hole extends towards the other end of the cylinder hole as it extends toward an offset side on which the crank shaft is offset from the center axis of the cylinder hole. The offset crank engine has the entire circumference of the crank-shaft-side opening edge of the cylinder hole chamfered without any bad influence on the sliding surface and posture of the piston to avoid interference between the crank-shaft-side opening edge of the cylinder hole and the connecting rod.

A fluid flow machine includes a casing including a cylinder and a crankshaft support. A piston is slidably disposed in the cylinder for reciprocating along an axis of the cylinder. A crankshaft includes a main bearing journal rotationally supported in the crankshaft support, a crankpin radially offset from an axis of the main bearing journal and a crank web connecting the main bearing journal and the crankpin. A multi-linkage connecting rod mechanism is connected between the piston and crankpin and includes a connecting rod, a first hinge link and a crankpin link pivotally connected to each other. A force transfer mechanism connects the multi-linkage connecting rod mechanism to the casing for transferring a vertical piston force into a horizontal crankpin force.

An offset in-line four cylinder engine has reduced vibration generated by a secondary inertia couple based on lateral pressures from pistons. A reference line passes through a shaft center of a crankshaft and is parallel or substantially parallel to cylinder axes of four cylinders as viewed in the axial direction of the crankshaft. As viewed in the axial direction of the crankshaft, the direction in which the reference line extends is referred to as first direction, and the direction perpendicular to the first direction is referred to as second direction. A distance between the shaft center of a first balancer shaft and the reference line as measured in the second direction is different from the distance between the shaft center of a second balancer shaft and the reference line as measured in the second direction, or a magnitude of a first unbalancing portion is different from a magnitude of the second unbalancing portion.

A compression ignition internal combustion engine (1), which includes a cylinder (2), a piston (3) reciprocably received within the cylinder (2), a pair of contra-rotating crankshafts (4, 5) rotatably mounted relative to the cylinder (2), a pair of connecting rods (6, 7) each having a first end (61, 71) connected to a crank journal (41, 51) of a respective one of the crankshafts (4, 5) and a second end (62, 72) connected to the piston (3). The engine (1) is configured such that the stroke of the piston (3) in a first direction toward the crankshafts (4, 5) causes each crankshaft (4, 5) to rotate by a first angle and the piston stroke in a second direction opposite the first direction causes each crankshaft (4,5) to rotate by a second angle different (β−α) from the first angle.

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.

A compressor has a crankcase in which a crankshaft is rotatably mounted in a crankspace. The crankcase contains at least one cylinder space in which a piston, mounted eccentrically on the crankshaft by way of a connecting rod, can be driven in reciprocating motion. The crankshaft is connected, via a gearing having a modulus m, to a drive source, wherein the gear wheel arranged on the crankshaft engages with the gear wheel on the drive source. The axis of rotation of the crankshaft is offset with respect to the center axis of the cylinder space by an amount dl which is a whole multiple of m/2. The center axis of the cylinder space is understood as the axis which proceeds from the center point of the base area of the cylinder space, perpendicular to this base area, and along which the piston moves. This makes it possible to change the transmission ratio of the gearing within an advantageous range, without it being necessary to undertake modifications to the external dimensions of the compressor or to the motive source. Depending on the transmission ratio, it is possible to reduce the operating noise of the compressor or to increase the air capacity.

This invention relates to the field of opposed-piston engines having two pistons in one cylinder configured to have facing heads. Specifically, this is an engine with two crankshafts, two piston heads facing each other in a single cylinder, with the following features: compact size relative to a comparable design, improved or equivalent performance to a comparable design as a result of any of the following: locating crankshafts in a different plane from the cylinder axes; the use of shared duct structures; and the use of an embedded compressor chamber for efficient operation to cover all volumetric requirements, fulfilling the entire thermodynamic cycle, and performing in addition the sweeping and overloading of air or an air/fuel mixture in the cylinder combustion chamber in each revolution of two or more crankshafts, either with or without advancement between the crankshafts.

A compression ignition internal combustion engine (1), which includes a cylinder (2), a piston (3) reciprocably received within the cylinder (2), a pair of contra-rotating crankshafts (4, 5) rotatably mounted relative to the cylinder (2), a pair of connecting rods (6, 7) each having a first end (61, 71) connected to a crank journal (41, 51) of a respective one of the crankshafts (4, 5) and a second end (62, 72) connected to the piston (3). The engine (1) is configured such that the stroke of the piston (3) in a first direction toward the crankshafts (4, 5) causes each crankshaft (4, 5) to rotate by a first angle and the piston stroke in a second direction opposite the first direction causes each crankshaft (4,5) to rotate by a second angle different () from the first angle.

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 reciprocating internal combustion engine having a line of cylinders arranged in parallel which are joined via connecting rods and pistons by means of a crank drive that is jointly mounted in a crankshaft bearing, whereby the crankshaft bearing of the crank drive can have been offset relative to the cylinder axis.