A system for monitoring operation of an internal combustion engine having a rocker arm assembly for actuating an engine valve is disclosed. The rocker arm assembly includes a first arm with a first end, a second arm also having a first end pivotally connected near the first end of the first arm along a pivot axle, at least one torsion spring coiled around an end of the pivot axle, a latch that when latched secures the first arm relative to the second arm in a latched mode, and when unlatched allows the first arm to move relative to the second arm in an unlatched mode. The system also employs a sensor attached to one of the first and second arms that can detect when the arms are moving relative to each other, and adapted to provide a signal indicating the sensed movement.

The disclosure relates to a hydraulic unit of an electrohydraulic gas exchange valve control system of an internal combustion engine. The hydraulic unit includes a hydraulic housing having a receiving opening, a piston guide, and a slave piston. The piston guide is fastened in the hydraulic housing by way of self-staking with a wall of the receiving opening.

The piston guide includes an outer part that brings about the self-staking and an inner part that guides the slave piston. An inner surface of the outer part is radially interspaced from the outer surface of the inner part in an axial region of the self-staking and the outer part and the inner part are connected in an axially form-locked manner so that a first end section of the outer part facing the gas exchange valve is partially or fully formed into an outer circumferential recess of the inner part.

An internal combustion engine is provided, which includes an engine body provided with a cylinder having openings for intake and exhaust, and valve bodies that open and close the openings, cam shafts, each provided with a cam lobe that depress the corresponding valve body to open the openings, and bearing members pivotally supporting the cam shaft via lubricating oil. The cam shaft includes cam journals pivotally supported by the bearing members, and a recess formed at a position of the cam journal, opposing the cam lobe in the circumferential direction, and depressed radially inwardly of the cam journal, the recess being deeper in an axial end part of the cam journal than an axial center part.

An internal combustion engine includes an engine body provided with a cylinder having openings for intake and exhaust, and valve bodies that open and close the openings, cam shafts provided with cam lobes that depress the valve bodies so as to open the openings, and bearing members that pivotally supports the cam shaft via lubricating oil. Each cam shaft includes cam journals pivotally supported by the bearing members, and a hollow bore extending in the axial direction of the cam shaft. When an area of the cam journal around the hollow bore is seen in a cross-sectional view perpendicular to the axial direction, a thickness on a projecting side of the cam lobe is X1, and a thickness on the opposite side to the cam lobe in the circumferential direction is X2, a relationship of X1>X2 is satisfied in at least a part of the cam journal.

A spool valve for controlling the flow of a fluid into a reciprocating piston cylinder. A spool is slideably inserted into an outer casing, the spool valve having a first and a second non-waisted end portions and having a waisted middle portion. The casing has an intake port and output port for fluids entering and exiting the casing. A first non-waisted end portion covers the intake port during a first valve-closed event as the spool slides in one direction within the casing. The waisted middle portion is sufficiently wide to uncover both the intake port and the output port during a valve-open event as the spool slides in one direction within the casing. A second non-waisted end portion covers the output port during a second valve-closed event as the spool slides in the same one direction within the casing.

A switching roller finger follower comprises an inner arm assembly. A pair of outer arms surround the inner arm assembly. A pivot axle connects the inner arm assembly to pivot with respect to the pair of outer arms from a starting position to a lost motion position. A latch assembly comprises a latch selectively movable from a latched position latching the inner arm assembly to move dependent with the outer arms and an unlatched position unlatching the inner arm assembly to pivot independent of the outer arms. A stop pin spans between the pair of outer arms and through an inner port in an axle of inner arm assembly. The stop pin comprises a clearance fit with the inner port, and the stop pin is configured pivotable independent of the outer arms. At least one return spring biases the stop pin toward the starting position.

An internal combustion engine includes an engine body provided with a cylinder having openings for intake and exhaust, and valve bodies that open and close the openings, cam shafts provided with cam lobes that depress the valve bodies so as to open the openings, and bearing members that pivotally supports the cam shaft via lubricating oil. Each cam shaft includes cam journals pivotally supported by the bearing members, and a hollow bore extending in the axial direction of the cam shaft. When an area of the cam journal around the hollow bore is seen in a cross-sectional view perpendicular to the axial direction, a thickness on a projecting side of the cam lobe is X1, and a thickness on the opposite side to the cam lobe in the circumferential direction is X2, a relationship of X1>X2 is satisfied in at least a part of the cam journal.

A system for monitoring operation of an internal combustion engine having a rocker arm assembly for actuating an engine valve is disclosed. The rocker arm assembly includes a first arm with a first end and a second end, at least one slider pad connected to the first arm near the second end of the first arm, a second arm also having a first end pivotally connected near the first end of the first arm along a pivot axle, a latch that when latched secures the first arm relative to the second arm in a latched mode, and when unlatched allows the first arm to move relative to the second arm in an unlatched mode. The system also employs a sensor attached to one of the arms that can detect when the arms are moving relative to each other, and adapted to provide a signal indicating the detected movement.

A type II valve train assembly that selectively opens first and second intake valves and first and second exhaust valves is provided. The valve train assembly includes an intake rocker arm assembly and an exhaust rocker arm assembly. The valve train assembly is configurable for operation in any combination of activated and deactivated states of engine braking and cylinder deactivation. The exhaust rocker arm assembly includes a first exhaust rocker arm, a second exhaust rocker arm and an engine brake exhaust rocker arm. A first exhaust HLA is associated with the first exhaust rocker arm. A second exhaust HLA is associated with the second exhaust valve. An exhaust actuation assembly selectively actuates to alter travel of the first and second exhaust HLA's to change a state of cylinder deactivation between activated and deactivated.

A switching roller finger follower (SRFF) assembly for valve actuation comprises an outer arm, an inner arm, an inner roller, a bearing axle and a pair of outer rollers. The outer arm is pivotally coupled to a pivot axle. The inner arm is at least partially disposed within the outer arm and pivotally coupled to the pivot axle. The inner roller assembly comprise a bushing and an outer ring. The bushing defines a curved slot therein. The bushing is fixed to the inner arm. The outer ring is configured to rotate around the bushing. The bearing axle extends through the curved slot. The pair of outer rollers are disposed on each end of the bearing axle.