A connecting rod for an internal combustion engine having an adjustable length between a first connecting rod eye and a second connecting rod eye. An eccentric member having a bearing bore which is positioned eccentrically to an outer diameter is rotated to adjust the length. The eccentric member is rotated by a rack and pinion drive and a double acting hydraulic cylinder.

A variable compression ratio internal combustion engine includes: a variable compression ratio mechanism arranged to vary an engine compression ratio in accordance with a rotation position of a first control shaft; an actuator arranged to vary and hold the rotation position of the first control shaft; and a link mechanism arranged to connect the actuator and the first control shaft, the link mechanism including; a second control shaft, a lever, a first arm portion, a first link pin, a second arm portion, and a second link pin, the first link pin having a diameter larger than a diameter of the second link pin.

A variable compression ratio internal combustion engine includes: a variable compression ratio mechanism arranged to vary an engine compression ratio in accordance with a rotation position of a first control shaft; an actuator arranged to vary and hold the rotation position of the first control shaft; and a link mechanism arranged to connect the actuator and the first control shaft, the link mechanism including; a second control shaft, a lever, a first arm portion, a first link pin, a second arm portion, and a second link pin, the first link pin having a diameter larger than a diameter of the second link pin.

A variable compression ratio (VCR) internal combustion engine includes an engine block defining a cylinder and a cylinder head mounted to the engine block and defining at least a part of a combustion chamber. The engine also includes a reciprocating primary piston arranged inside the cylinder and configured to compress a mixture of air and fuel and a crankshaft arranged in the engine block and rotated by an application of a combustion force to the primary piston. The engine additionally includes a secondary piston mounted in the cylinder head, movably with respect to the combustion chamber and a mechanism configured to shift the secondary piston in the cylinder head and thereby vary a volume of the combustion chamber and a compression ratio of the engine. A vehicle employing such an engine is also disclosed.

A variable compression ratio apparatus may include: a piston pin; a small diameter eccentric cam disposed on a piston; a large diameter eccentric cam disposed between the small diameter eccentric cam and a small end portion of a connecting rod; a first plunger movably disposed in a first plunger space inside the piston pin; a second plunger movably disposed in a second plunger space formed inside the piston pin; and first and second oil injection nozzles disposed at a lower portion of the piston. In particular, the first and second oil injection nozzles control a control position of the first and second plungers by supplying hydraulic pressure to an end portion of the first plunger and the other portion of the second plunger through first and second guide passages formed inside the piston by injecting oil to the lower portion of the piston.

An internal combustion engine includes a crankshaft rotatably supported by an engine block, and rotatable about a crank axis. A control shaft is rotatably supported by the engine block, and rotatable about a control axis. A link rod is rotatably connected to the crankshaft. A lower connecting rod includes a first end rotatably connected to the link rod, and a second end rotatably connected to the control shaft. An upper connecting rod is rotatably connected to the link rod and a piston. The second end of the lower connecting rod and the control shaft are rotatably connected at a location offset from the control axis to define an eccentric connection relative to the control axis. Rotation of the control shaft about the control axis rotates the second end of the lower connecting rod about the control axis to adjust a compression stroke length of the piston.

A variable length connecting rod comprises a connecting rod body, an eccentric member, a hydraulic cylinder, a hydraulic piston, a check valve, a switching mechanism and a hydraulic mechanism. The check valve permits a flow of hydraulic oil from a primary side of the check valve to a secondary side of the check valve and prohibits the flow from the secondary side to the primary side. The switching mechanism comprises a single switching pin. The connecting rod body is formed with first to fourth oil paths. The switching pin is switched between a first position making the first oil path communicate with the fourth oil path and making the second oil path communicate with the third oil path, and a second position making the first oil path communicate with the third oil path and making the second oil path communicate with the fourth oil path.

Systems and methods are provided for varying a compression ratio in an engine having a pressure reactive piston. The pressure reactive piston may include a piston crown, and a spring positioned within the piston crown, wherein the spring includes a first ring, a second ring comprising a plurality of apertures, a rolling element positioned within each of the plurality of apertures, and a third ring. The first ring, the second ring, and the third ring of the spring may be arranged concentrically and the second ring may be positioned between the first ring and the third ring.

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.

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.