An exhaust valve rocker arm assembly operable in a drive mode and an engine braking mode includes a rocker shaft, a rocker arm, a hydraulic lash adjuster assembly, an accumulator assembly and a locking pin. The rocker shaft has an oil gallery defined thereon. The rocker arm receives the rocker shaft and is configured to rotate around the rocker shaft. The rocker arm has an oil feed channel that is fluidly connected to the oil gallery. The rocker arm further defines an engine brake relief hold and an accumulator relief hole. The accumulator assembly is disposed in the rocker arm and is fluidly coupled to the hydraulic lash adjuster through an engine brake relief hole. The locking pin assembly is disposed in the rocker am and is selectively movable by a high pressure fluid from a closed position to an open position.

An engine system and valvetrain can comprise a rocker shaft combined with a first block, a first cylinder deactivation oil control valve in the first block, a second cylinder deactivation oil control valve in the first block. Also, a second block can be combined with the rocker shaft with a third cylinder deactivation oil control valve and an early exhaust valve opening oil control valve in the second block. The rocker shaft can comprise oil infeeds and oil outfeeds configured for supplying hydraulic pressure to the first and second blocks, the blocks can distribute the pressure to the control valves, and the blocks can return pressure to the rocker shaft. Intake and exhaust rocker arms can receive the returned pressure to actuate valves, and the rockers arms can be arranged line-to-line with no overlap during motion.

Methods and systems are provided for oil flow for hydraulic lash adjusters of a vehicle engine. In one example, an engine cylinder bank includes a plurality of deactivatable hydraulic lash adjusters and a plurality of non-deactivatable hydraulic lash adjusters. A first linear oil supply passage and a second linear oil supply passage are formed within the cylinder bank and extend linearly through the cylinder bank without bends or curvature to the deactivatable and non-deactivatable hydraulic lash adjusters, with the deactivatable and non-deactivatable hydraulic lash adjusters having a same length.

A compression release type of engine brake socket module is provided between an exhaust rocker arm rotating with respect to a rocker arm shaft and a valve bridge connecting an exhaust valve of an engine. In particular the socket module incudes: a housing which includes an inlet through which brake oil is introduced, a brake piston mounting portion, and a reset member mounting portion communicating with the brake piston mounting portion; a brake piston that is provided to be movable in the brake piston mounting portion; a stopper disposed on one side of an inner space of the housing to limit a moving position of the brake piston; and a reset member that is provided in the reset member mounting portion, and that discharges the brake oil by selectively contacting a push pin coupled to an upper portion of a cylinder head.

A control valve for a valve train in an internal combustion engine using four-way control logic for dynamic skip fire control of a pair of cylinders is described. A four cylinder engine can be controlled using two control valves, with each control valve controlling a pair of cylinders. Each control valve has four ports: one control port for each cylinder, a pressure inlet port, and a tank port. The control valve is used to activate or deactivate a cylinder's intake and/or exhaust valves.

An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine braking mode includes: a rocker shaft that defines a pressurized oil supply conduit; a rocker arm that receives the rocker shaft and rotates around the rocker shaft, the rocker arm including a rocker arm oil supply passage defined in the rocker arm; a valve bridge for engaging a first exhaust valve and a second exhaust valve; a hydraulic lash adjuster assembly, disposed on the rocker arm, including a first plunger body movable between a first position and a second position; and a check valve, disposed on the rocker arm, including an actuator for selectively releasing pressure in the hydraulic lash adjuster assembly. In the engine braking mode, by rotation of the rocker arm the pressurized oil supply conduit is brought into fluid communication with the rocker arm oil supply passage.

A compression-release brake system for operating an exhaust valve of an engine during an engine braking operation. The compression-release brake system comprises a self-contained compression brake control module (CBCM) operatively coupled to the exhaust valve for controlling a lift and a phase angle thereof. The CBCM includes a casing defining an actuator cavity, a actuation piston disposed outside the casing so as to define an actuation piston cavity between the casing and the actuation piston, and a check valve provided between the actuation piston cavity and a compression brake actuator disposed in the actuator cavity. The actuation piston reciprocates relative to the casing. The compression brake actuator includes an actuator element and a biasing spring. The actuator element selectively engages the check valve when deactivated so as to unlock the actuation piston cavity and disengages from the check valve when activated so as to lock the actuation piston cavity.

A hydraulic lash adjuster includes a longitudinally extending pushrod having a proximal end and a distal end, and a cavity located at the distal end and a piston received in the cavity. The piston includes an internal reservoir and a fluid pathway to the internal reservoir. The fluid pathway includes a longitudinal passage and a radial passage.

A compression release type of engine brake socket module is provided between an exhaust rocker arm rotating with respect to a rocker arm shaft and a valve bridge connecting an exhaust valve of an engine. In particular the socket module incudes: a housing which includes an inlet through which brake oil is introduced, a brake piston mounting portion, and a reset member mounting portion communicating with the brake piston mounting portion; a brake piston that is provided to be movable in the brake piston mounting portion; a stopper disposed on one side of an inner space of the housing to limit a moving position of the brake piston; and a reset member that is provided in the reset member mounting portion, and that discharges the brake oil by selectively contacting a push pin coupled to an upper portion of a cylinder head.

An exhaust valve rocker arm assembly operable in an engine braking mode includes a rocker arm configured to rotate about a rocker shaft defining a pressurized fluid supply conduit, the rocker arm having a fluid supply passage defined therein. An engine brake capsule is disposed in the rocker arm and in fluid communication with the fluid supply passage. The engine brake capsule is configured to selectively move from a retracted position to an extended position where the engine brake capsule engages and partially opens an exhaust valve to perform a bleeder brake operation. A reset pin assembly is configured to selectively drain fluid from the engine brake capsule.