A hydraulic control system for a variable compression ratio engine, comprises: a control cylinder comprising a piston, a body in which two hydraulic chambers with equivalent sections are defined on either side of the piston and a return device arranged in one of the chambers, a hydraulic control circuit comprising: at least one duct connecting the two chambers to each other, and a controlled fluid discharging device for establishing or blocking a fluid communication between the chambers, at least one duct connecting one of the chambers to a low-pressure oil supply, and a refill valve, at least one duct connecting an oil outlet to at least one of the chambers, and a relief valve.

Methods and systems for optimizing fuel economy and maintaining particulate emissions below a threshold of an engine system in a vehicle. An engine system has port fuel injection, direct injection, variable compression ratio, and independent compression/expansion. A processor predicts settings for the four systems that optimize for a fuel economy that is maximized. A particulate rate of the engine system is computed based on the settings. A determination is made of whether the particulate rate is below a threshold. When the particulate rate is below the threshold, command signals are delivered to actuators of the systems to move to the settings. When the threshold is exceeded, the settings are revised to maintain the particulate below the threshold while optimizing for fuel economy.

At the time of increasing an actual intake air amount by increasing a valve overlap period of intake and exhaust valves (2; 3), an actual compression ratio is temporarily decreased to be lower than a steady-state target compression ratio. This makes it possible to increase the valve overlap period without causing interference of the intake and exhaust valves (2; 3) with a piston (8).

An internal combustion engine has a multi-joint crank drive wherein the multi-joint crank driver includes a plurality of coupling members which are rotatably supported on crank pins of a crank shaft and a plurality of hinged connecting rods which are rotatably supported on crank pins of an eccentric shaft wherein each of the coupling members is pivotally connected to a piston connecting rod of a piston of the internal combustion engine and one of the articulation connecting rods. In order to enable to largely or completely compensate inertia forces, it is proposed according to the invention to equip the internal combustion engine with a single balance which serves for neutralizing second order inertia forces.

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.

A compression ratio varying arrangement of an engine is adapted to work with a crankshaft having at least one crankpin offset from the centerline of the crankshaft. An eccentric has an internal bore engaged with the crankpin, and an external cylindrical surface that has a centerline that is offset from the centerline of the internal bore. A connecting rod is engaged with the external cylindrical surface of the eccentric, and a piston is connected to the connecting rod. An eccentric lever is attached to the eccentric. A compression ratio adjustment link is connected to the eccentric lever. A compression ratio adjustment mechanism is connected to the compression ratio adjustment link. The compression ratio adjustment mechanism controls the orientation of the connecting rod eccentric, and thereby the compression ratio of the engine, by extending or retracting the compression ratio adjustment link.

A device for changing a compression ratio of a cylinder unit of a reciprocating piston internal combustion engine has an eccentric bushing which is rotatably arranged in a bore of a connecting rod eye. Said eye encloses a crank pin of a crankshaft, and the bushing is rotatably guided in the bore and can be locked via locking openings, which are arranged to be offset from each other by preferably approximately 180°. The connecting rod has a locking apparatus which interacts optionally with the locking openings and via which the eccentric bushing can only ever be transferred from one position to the next. The locking apparatus has a sliding guideway extending parallel to the longitudinal axis of the bore of the connecting rod bearing eye. The sliding guide interacts with actuating pins arranged in the locking openings and can be displaced radially with respect to the bushing.

A variable compression connecting rod system (10) located in an internal combustion engine (12) and a method of assembly can include a connecting rod (28) mountable to a piston pin (26) having a first longitudinal axis at one end and 5 mountable to a crankpin (22) having a second longitudinal axis at a second end portion (36). A hydraulically actuated eccentric rotor (52) rotatable about one of the first and second longitudinal axis. The eccentric rotor (52) including first and second vanes (54a, 54b) for driving the rotor between first and second angular positions in response to fluid pressure acting on the first and second vanes. The eccentric rotor 10 (52) having an eccentric surface area with different radial distances (80, 82) movable into alignment with a longitudinal axis of the connecting rod (28) for varying a longitudinal length of the connecting rod (28) between the first and second longitudinal axis.

Apparatus with variable compression ratio and variable expansion ratio for an internal combustion engine, mounted on the engine crankshaft and the assembly of the piston-connecting rod, comprising an actuating motor, a worm, a worm gear, a sun gear, a first transmission shaft, a plurality of the transmission shafts, a first eccentric sleeve, a plurality of eccentric sleeve, a front gear of the first eccentric sleeve, a plurality of the front gear of the eccentric sleeve, a plurality of the rear gear of the eccentric sleeve, a planetary gear, the rear gear of the first transmission shaft, a plurality of the front gear of the transmission shaft, and a plurality of the rear gear of the transmission shaft. An angle α between the axis of the first transmission shaft and the axis of the crankshaft is not zero, the other axes of the transmission shafts with the axis of the crankshaft coincide, or parallel but do not coincide, or form a non zero angle.

A device for changing a compression ratio of a cylinder unit of a reciprocating piston combustion engine is provided. An eccentric bushing is rotatably arranged in a receiving bore hole of a bearing eye of a connecting rod (“conrod”). The conrod bearing eye is formed by a conrod upper part and a conrod lower part, and which surrounds a crankpin of a crankshaft. In addition, the eccentric bushing is rotatably guided in the receiving bore hole and can be locked preferably in two positions which are offset from one another by approximately 180° in the circumferential direction of the eccentric bushing. In order to achieve a targeted rotation of the eccentric bushing in the bore hole of the conrod bearing eye between the locking positions, a freewheel is arranged between an outer casing surface of the eccentric bushing and the receiving bore hole of the conrod bearing eye.