An apparatus includes a valve and an actuator. The valve has a portion movably disposed within a valve pocket defined by a cylinder head of an engine. The valve is configured to move relative to the cylinder head a distance between a closed position and an opened position. The portion of the valve defines a flow opening that is in fluid communication with a cylinder of an engine when the valve is in the opened position. The actuator is configured to selectively vary the distance between the closed position and the opened position.

Improvements in a vertical sliding valve arm has been disclosed with systems and methods related to eliminating the common pivot-type rocker arm and reversing the use of the valve spring in internal combustion engines. More specifically, the camshaft lobes activate a sliding valve arm to close the engine valve instead of opening it and the valve spring is used to push open the valve instead of closing it.

A device for actuating at least one valve in an internal combustion engine includes a camshaft arrangement including a hollow outer shaft and an inner shaft, which is concentrically mounted inside of the outer shaft to be pivotable relative to the outer shaft. A first cam lobe is mounted on one of the inner shaft and the outer shaft in a rotationally fixed manner and a second cam lobe is mounted on the other of the inner shaft and the outer shaft in a rotationally fixed manner. The device further includes a rocker arm arrangement including a first primary rocker arm, which is arranged to follow the first cam lobe and arranged to actuate a first valve when it follows the first cam lobe. The rocker arm arrangement further includes an auxiliary rocker arm, which is arranged to follow the second cam lobe. The auxiliary rocker arm is adapted to actuate the first primary rocker arm so that an opening tune of the first valve may be extended by the auxiliary rocker arm following the second cam lobe.

A synchronous belt drive system having: a synchronous belt with a tensile cord of high-modulus fiber such as glass, carbon, PBO, or aramid; a driver sprocket and at least one driven sprocket, at least one of which is an obround sprocket; and a tensioner having: a base having a cylindrical portion extending axially with a radially outer surface and a receiving portion, an eccentric arm pivotally engaged with the radially outer surface, a torsion spring disposed within the receiving portion, the torsion spring applying a biasing force to the eccentric arm, and a pulley journalled to the eccentric arm. Preferably, no one of the eccentric arm, pulley, or torsion spring is axially displaced along an axis A-A from the others. The obround sprocket has a toothed surface and at least one linear portion disposed between two arcuate portions having a constant radius, the linear portion having a predetermined length.

A valve bridge system comprises a valve bridge configured to extend between at least two engine valves of an internal combustion engine. In one embodiment, a valve bridge guide is operatively connected to the valve bridge and configured to extend between at least two valve springs respectively corresponding to the at least two engine valves, the valve bridge guide defining a surface conforming to a valve spring of the at least two valve springs. In another embodiment, the valve bridge guide may comprise at least a first member maintained in a first fixed position relative to and at a predetermined distance from the valve bridge. In both embodiments, the valve bridge guide is configured to avoid contact with the valve bridge in a controlled state, but to permit contact with valve bridge to resist uncontrolled movement of the valve bridge.

A camshaft housing includes two longitudinal frame bars and lateral frame bars. The longitudinal frame bars extend in the axial direction of a camshaft. The lateral frame bars extend between the longitudinal frame bars. A bearing portion is arranged in each of the lateral frame bars to rotationally support the camshaft. Each lateral frame bar has a bolt hole to receive a bolt that is inserted through the bolt hole to fix the camshaft housing to a cylinder head body. The bolt hole extends through the lateral frame bar and is arranged on the outer side of the bearing portion in the longitudinal direction of the lateral frame bar. Each longitudinal frame bar has a vibration reducing portion. The cross-sectional area of the longitudinal frame bar gradually changes in the longitudinal direction of the longitudinal frame bar.

A collapsible valve bridge actuation system that is configured to alter the lift of poppet valves in a reciprocating piston machine cylinder. The system has a rocker arm configured to be actuated by a cam lobe, and a collapsible valve bridge device that is functionally attached to the rocker arm. The device has a deactivation assembly that contains lock pins within a housing and springs. Also, the device is configured to remain rigid, partially collapse, or fully collapse. The extent of collapse is a function of the strength of the springs.

Improvements in a vertical sliding valve arm has been disclosed with systems and methods related to eliminating the common pivot-type rocker arm and reversing the use of the valve spring in internal combustion engines. More specifically, the camshaft lobes activate a sliding valve arm to close the engine valve instead of opening it and the valve spring is used to push open the valve instead of closing it.

There is provided an assembling structure of an engine. An oil control valve unit is configured to control oil pressure in a variable valve timing device of the engine. The oil control valve unit is installed on a cylinder head. The cylinder head is assembled to a crankcase. An outer wall of the cylinder head is formed with an opening into which the oil control valve unit is partially inserted. A mating surface of the cylinder head and the crankcase is fastened by at least a pair of bolts spaced apart across the opening.

There is provided an installation structure of an oil control valve unit configured to control a hydraulic pressure in a variable valve timing device of an engine by a control valve supported by a valve housing. The engine is formed with an installation surface on which the valve housing is installed. The valve housing is installed on the installation surface by a plurality of bolts. Two bolts of the plurality of bolts are attached at facing positions across a center of the valve housing in a direction along a cylinder axial direction of the engine.