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.

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.

A drive circuit (203) of an actuator (2) calculates an actual working angle from an actual operation quantity with reference to a reference table used to calculate a target operation quantity, and transmits the actual working angle and the actual operation quantity to a command unit (4). The command unit (4) determines whether or not the received values of the actual working angle and the operation quantity correspond to the valve working angle and the operation quantity of the reference table stored in the command unit (4), to detect a discrepancy between the operation modes of the actuator (2) and the command unit (4).

The variable valve actuating device (20) comprises a valve lifter (24) interposed between a swing end of a rocker arm 22 and a stem end of an engine valve (17), and a switch pin (53) slidably received in the valve lifter (24) so as to selectively abut the end surface of the valve stem as the valve lifter is actuated by a cam (21a). The swing end of the rocker arm abuts an upper end of a projection (55) projecting from the upper end of the valve lifter via an engagement feature (26b, 55a) that prevents a rotational movement of the valve lifter relative to the swing end around the axial line of the valve stem.

A valve switching apparatus includes a rocker arm coming into contact with a cam to open and close a valve along with a rotation of the cam, and an eccentric generation means provided to the rocker arm so as to allow an eccentric position to be changed by rotation thereof.

A valvetrain includes a rocker arm assembly having a rocker arm and an electromagnetic latch assembly. An electromagnet of the latch assembly is housed within a chamber formed by the rocker arm. Passageways suitable for oil cooling of the electromagnet are formed through and inside the rocker arm. In some embodiments, oil for cooling is supplied through a pivot. In some embodiments, oil for cooling is obtained from oil splash. Oil cooling may allow modes of operation such as of dynamic cylinder deactivation and dynamic variable valve actuation to be used without overheating the electromagnet.

Embodiments are directed toward an engine. In some embodiments, the engine includes a water pump and a balancer shaft. In some embodiments, the water pump has a plain bearing. In some embodiments, plain bearing is supplied with pressurized oil. In some embodiments, the balancer shaft drives the water pump as well as cam shafts.

A continuously variable valve lift apparatus may include a camshaft, a cam portion on which a cam is formed and to which the camshaft is inserted, a slider housing to which the cam portion is rotatably inserted and is movable with respect to the camshaft, a control portion selectively changing the position of the slider housing, an output portion rotatable around a pivot shaft and to which a valve shoe is formed. The valve shoe drives a valve unit.

A columnar-type hydraulic tappet, provided with a housing, a plunger moving axially with respect to the housing being mounted in an inner cavity of the housing, a high pressure cavity used for a hydraulic medium extending between a lower end surface of the plunger and a lower side of the housing, a first ring groove being arranged below a head portion of the plunger, a second ring groove being arranged at a central portion of the plunger, a plunger central wall being between the first ring groove and the second ring groove, the second ring groove being a concave wide ring groove, wherein at least one plunger oil inlet hole being arranged on the plunger concave wide ring groove or the plunger central wall, a bottom portion edge of the plunger oil inlet hole containing flanging facing towards an inner cavity of the plunger.