An engine braking system includes a camshaft, a follower, an exhaust armature, a lever, and a hydraulically actuated piston. The camshaft includes at least one cam. The cam has a lobe and a brake bump. The follower engages the cam. The exhaust armature is coupled to the follower. The lever is coupled to the exhaust armature. The hydraulically actuated piston moves the lever. Hydraulic actuation of the piston causes a change in lash distance between the cam and the follower. In an engine brake mode, the follower contacts the cam throughout rotation of the cam.

An engine includes a block containing multiple valves, and a camshaft defining multiple cams for rotation about a camshaft axis. A valve lift assembly is operatively associated with a respective one of the cams and a respective one of the valves to transfer motion from the cam to the valve by reciprocal motion of the valve lift assembly along a lift axis. The assembly includes a follower and a follower control mechanism. The follower is disposed in contact with the cam at a contact point that defines a contact path extending along a surface of the cam as the cam rotates about the camshaft axis. The follower is moveable through an adjustment range to change the position of the contact point along the contact path at a given angular position of the cam. The follower control mechanism is operable to control the movement of the follower within the adjustment range.

A valve train assembly includes a first exhaust valve, a second exhaust valve, and a valve bridge including a main body and a lever rotatably coupled to the main body, the main body configured to engage the first exhaust valve, and the lever configured to engage the second exhaust valve. An exhaust valve rocker arm assembly is configured to selectively open the first and second exhaust valves, the exhaust valve rocker arm assembly including an exhaust valve rocker arm with a hydraulic lash adjuster (HLA) assembly coupled thereto, the HLA assembly in contact with the valve bridge main body. An engine brake rocker arm assembly is configured to selectively open the second exhaust valve and including an engine brake rocker arm with a combined HLA and added motion capsule coupled thereto. The combined HLA and added motion capsule is configured to selectively engage and rotate the lever.

Variable-length assemblies, including lost motion assemblies eliminate hydraulic or pneumatic working fluids for operation in internal combustion engine valve trains and may be integrated into valve rocker arm pivots. An example piston and actuating plate are provided with working surfaces that interact when the actuating plate is rotated relative to the piston. The working surfaces include ramped transition portions and may include upper and lower flat portions. A shallow ramp angle prevents counter-rotation of the actuating plate under load. Actuating assemblies include an actuating solenoid includes a plunger that engages and pivots the actuating arm to cause rotation of the actuating plate relative to the piston and changes the state of the lost motion assembly from an off state, where motion may be absorbed, to an on state where the lost motion assembly is rigid and does not absorb motion.

Variable-length assemblies, including lost motion assemblies eliminate hydraulic or pneumatic working fluids for operation in internal combustion engine valve trains and may be integrated into valve rocker arm pivots. An example piston and actuating plate are provided with working surfaces that interact when the actuating plate is rotated relative to the piston. The working surfaces include ramped transition portions and may include upper and lower flat portions. A shallow ramp angle prevents counter-rotation of the actuating plate under load. Actuating assemblies include an actuating solenoid includes a plunger that engages and pivots the actuating arm to cause rotation of the actuating plate relative to the piston and changes the state of the lost motion assembly from an off state, where motion may be absorbed, to an on state where the lost motion assembly is rigid and does not absorb motion.

A rocker arm system provides variable ratio valve actuation. A rocker arm extends between a pair of ends. One end receives a movement input and the second end delivers a movement output. The rocker arm reacts against a bearing cap to deliver the movement output in response to the movement input. The bearing cap includes a load surface facing the rocker arm that defines a trajectory of the rocker arm.

A valve train assembly having a valve train carrier including a body having a cartridge cavity formed in the body, a hydraulic lash adjuster adjustment (HLA) assembly, and a cartridge removably disposed in the cartridge cavity. The cartridge includes a main body defining an inner bore, wherein the HLA assembly is disposed in the inner bore, and the cartridge is sized and shaped for insertion into the cartridge cavity formed in an underside of the valve train carrier. The cartridge is configured to have a valve train lash set prior to insertion into the cartridge cavity. A rocker arm assembly includes a body configured to engage the hydraulic lash adjustment (HLA) assembly, an end having a socket formed therein, and an e-foot extending through the socket and coupled to the end, the e-foot configured to maintain substantially flat contact with a top surface of an engine valve.

A rocker arm system provides variable ratio valve actuation. A rocker arm extends between a pair of ends. One end receives a movement input and the second end delivers a movement output. The rocker arm reacts against a bearing cap to deliver the movement output in response to the movement input. The bearing cap includes a load surface facing the rocker arm that defines a trajectory of the rocker arm.

A valve train assembly includes a first exhaust valve, a second exhaust valve, and a valve bridge including a main body and a lever rotatably coupled to the main body, the main body configured to engage the first exhaust valve, and the lever configured to engage the second exhaust valve. An exhaust valve rocker arm assembly is configured to selectively open the first and second exhaust valves, the exhaust valve rocker arm assembly including an exhaust valve rocker arm with a hydraulic lash adjuster (HLA) assembly coupled thereto, the HLA assembly in contact with the valve bridge main body. An engine brake rocker arm assembly is configured to selectively open the second exhaust valve and including an engine brake rocker arm with a combined HLA and added motion capsule coupled thereto. The combined HLA and added motion capsule is configured to selectively engage and rotate the lever.

An engine braking system includes a camshaft, a follower, an exhaust armature, a lever, and a hydraulically actuated piston. The camshaft includes at least one cam. The cam has a lobe and a brake bump. The follower engages the cam. The exhaust armature is coupled to the follower. The lever is coupled to the exhaust armature. The hydraulically actuated piston moves the lever. Hydraulic actuation of the piston causes a change in lash distance between the cam and the follower. In an engine brake mode, the follower contacts the cam throughout rotation of the cam.