A crankshaft has a main journal surrounded by a main bearing defining a groove provided with oil from an oil gallery and at least one oil inlet formed in the main journal providing oil from the groove into the main journal. A first crankpin journal is connected to a first side of the main journal by way of a first web. A second crankpin journal is connected to a second side of the main journal by way of a second web. Pairs of crankpin bearings are provided around each of the first and second crankpin journals. Each crankpin bearing supports a piston rod thereon. Each of the first and second crankpin journals has a pair of oil outlets providing oil to a respective crankpin bearing. Oil passageways in the crankshaft provide the pairs of oil outlets in both the first and second crankpin journals with oil from the main journal.

A device lubricates a big-end bearing on a crankshaft of an internal combustion engine. The device includes a piston with a fluid channel and an outlet channel fluidically connected thereto, and a connecting rod. The connecting rod has a small connecting rod eye, a large connecting rod eye and a connecting channel. The small connecting rod eye is fluidically connected to the outlet channel. The connecting channel forms a fluidic connection between the small and large connecting rod eyes so that a cooling lubricant fluid can be supplied from the fluid channel to the large connecting rod eye via the outlet channel, the small connecting rod eye and the connecting channel. In this way, the big-end bearing can be lubricated by cooling oil from the fluid channel of the piston.

A device lubricates a big-end bearing on a crankshaft of an internal combustion engine. The device includes a piston with a fluid channel and an outlet channel fluidically connected thereto, and a connecting rod. The connecting rod has a small connecting rod eye, a large connecting rod eye and a connecting channel. The small connecting rod eye is fluidically connected to the outlet channel. The connecting channel forms a fluidic connection between the small and large connecting rod eyes so that a cooling lubricant fluid can be supplied from the fluid channel to the large connecting rod eye via the outlet channel, the small connecting rod eye and the connecting channel. In this way, the big-end bearing can be lubricated by cooling oil from the fluid channel of the piston.

A telescopic control connecting rod for a variable compression ratio engine, comprises: a small end having, respectively, an eye and a piston at its ends; a big end serving as cylinder body in which the piston defines a first and a second hydraulic chamber, and a third side chamber located between the first and the second hydraulic chambers; the big end comprises two coaxial side bearings configured to establish a pivot link with a fixed part of the engine; a lubrication circuit comprising at least a first duct provided in the big end, connecting an inner space of each side bearing and the third chamber, whatever the length of the connecting rod, and comprising at least one second duct provided in the small end, connecting the third chamber and the eye.

A telescopic control connecting rod for a variable compression ratio engine, comprises: a small end having, respectively, an eye and a piston at its ends; a big end serving as cylinder body in which the piston defines a first and a second hydraulic chamber, and a third side chamber located between the first and the second hydraulic chambers; the big end comprises two coaxial side bearings configured to establish a pivot link with a fixed part of the engine; a lubrication circuit comprising at least a first duct provided in the big end, connecting an inner space of each side bearing and the third chamber, whatever the length of the connecting rod, and comprising at least one second duct provided in the small end, connecting the third chamber and the eye.

A controller for a vehicle that includes an internal combustion includes processing circuitry. The processing circuitry obtains a predicted temperature outside the vehicle and estimates the viscosity of a lubricating oil based on the oil pressure and the oil temperature of the lubricating oil when the internal combustion engine satisfies a specific operation condition. When the processing circuitry determines that there is a likelihood of a cranking failure occurring in the internal combustion engine on condition that the predicted temperature is less than a threshold value that is based on the viscosity, the processing circuitry outputs a notification signal indicating that that there is a likelihood of a cranking failure occurring in the internal combustion engine.

A controller for a vehicle that includes an internal combustion includes processing circuitry. The processing circuitry obtains a predicted temperature outside the vehicle and estimates the viscosity of a lubricating oil based on the oil pressure and the oil temperature of the lubricating oil when the internal combustion engine satisfies a specific operation condition. When the processing circuitry determines that there is a likelihood of a cranking failure occurring in the internal combustion engine on condition that the predicted temperature is less than a threshold value that is based on the viscosity, the processing circuitry outputs a notification signal indicating that that there is a likelihood of a cranking failure occurring in the internal combustion engine.

An internal combustion engine is provided, which includes an engine body provided with a cylinder and a piston reciprocatably accommodated in the cylinder, a crankshaft that converts reciprocating movement of the piston into rotational movement, and a bearing member pivotally supporting the crankshaft via lubricating oil. The crankshaft includes a crank journal pivotally supported by the bearing member, and a counterweight extending radially outward from an axial end part of the crank journal. The crank journal has a recess formed in a part thereof corresponding to the extended position of the counterweight, the recess being depressed radially inwardly. The recess is deeper at the axial end part of the crank journal than an axial center part.

An internal combustion engine is provided, which includes an engine body provided with a cylinder and a piston reciprocatably accommodated in the cylinder, a crankshaft that converts reciprocating movement of the piston into rotational movement, and a bearing member pivotally supporting the crankshaft via lubricating oil. The crankshaft includes a crank journal pivotally supported by the bearing member, and a counterweight extending radially outward from an axial end part of the crank journal. The crank journal has a recess formed in a part thereof corresponding to the extended position of the counterweight, the recess being depressed radially inwardly. The recess is deeper at the axial end part of the crank journal than an axial center part.

A rocker shaft assembly configured to support a rocker arm and deliver oil to the rocker arm and related method of making is provided. The rocker shaft assembly includes a core shaft and a sleeve. The core shaft has a core body including a main oil supply channel formed thereon. The sleeve has passages formed thereon. The sleeve is disposed around the core shaft. The main oil supply channel aligns with at least one of the passages on the sleeve. The main oil supply is milled into the core shaft.