A valvetrain assembly comprises a deactivatable rocker arm where a pushrod is configured to transfer a valve lift profile through to a valve end to a valve or valve bridge. A castellation assembly in a carrier and alternative two-piece rocker arm assemblies with rotary or linear actuators are shown for deactivating the transfer of the valve lift profile.

A method for controlling vehicle speed comprises selecting an engine speed profile for a vehicle. Road grade data is received and processed to determine a road grade for the vehicle. Vehicle speed data is received and processed to determine a vehicle speed for the vehicle. A cylinder deactivation mode for a valvetrain of a multi-cylinder engine of the vehicle is selected. The cylinder deactivation mode comprises deactivating one or more intake valve, exhaust valve, and fuel injection for one or more cylinder of the multi-cylinder engine. The selected cylinder deactivation mode provides a controlled deviation from the selected engine speed profile at the road grade and vehicle speed.

A latch assembly comprises a latch pin configured to reciprocate in a latch bore. The latch pin comprises a main body comprising a first plug end, a second plug end, and a clearance between the first plug end and the second plug end. The latch pin is configured to selectively move in the latch bore. A rocker arm assembly can comprise the latch assembly. An outer arm can be configured to rotate about a rocker shaft and comprise the latch bore. An inner arm can at least be partially disposed within the outer arm and configured to rotate. When the latch pin is in the activated position, the inner arm is configured to transfer force to the outer arm via the latch pin. When the latch pin is in the deactivated position, the inner arm is configured to move in the clearance and in the lost motion gap.

An overhead cam engine system comprises a rotating overhead exhaust cam rail comprising a plurality of exhaust lobes. A first switching roller finger follower actuates a first exhaust valve, and is configured to switch between a first lift profile and a second lift profile. A second switching roller finger follower is coupled to actuate a second exhaust valve, and is configured to switch between a third lift profile and a fourth lift profile. The third and fourth lift profile are different than the first and second lift profile. An actuation assembly is connected to switch the first switching roller finger follower and the second switching roller finger follower to select between at least three exhaust lift modes to open and close the first exhaust valve and the second exhaust valve using combinations of the first, second, third and fourth lift profiles.

A rocker arm assembly can include an outer arm having an outer rocker shaft bore configured to receive a rocker shaft and an inner arm having an inner rocker shaft bore configured to receive the rocker shaft. The inner arm can be configured to selectively rotate. A latch pin can be movably seated in the outer arm and configured to move between a latched position and an unlatched position. The rocker arm assembly can further include a lost motion spring. The lost motion spring can include a first end connected to a connecting portion of the inner arm above the inner rocker shaft bore and a second end connected to the outer arm. The inner arm can include an inner arm stop member configured contact with a corresponding outer arm stop member of the outer arm.

A compression-release engine brake system operating an exhaust valve of an engine during a compression-release engine braking operation. The compression-release brake system comprises an exhaust rocker arm and a brake reset device disposed in a reset bore formed in the exhaust rocker arm. The brake reset device comprises a reset check valve, a slider-piston slidably disposed in the reset bore and an external slider bias spring biasing the piston foot away from the brake reset device. The external slider bias spring is disposed outside the reset bore and around the piston-slider. The brake reset device permits pressurized hydraulic fluid to flow from a supply conduit to a reset conduit to supply a brake actuation piston when the reset check valve is open. The actuation piston extends and engages the exhaust valve toward the end of a compression stroke of the internal combustion engine, and the brake reset device resets.

A rocker arm assembly can comprise a cam side rocker arm portion configured to selectively rotate about a pivot location. The cam side rocker arm portion can comprise a first socket above the pivot location, and a cam end configured to receive a lift profile from a cam lobe. A valve side rocker arm portion can be configured to rotate about the pivot location relative to the cam side rocker arm portion. The valve side rocker arm portion can comprise a second socket above the pivot location. A lost motion spring can span between the first socket and the second socket.

A valve actuation device for actuating a first and second gas exchange valve of an internal combustion engine. A tilting lever is pivotable between a first starting position and a first actuation position and a valve bridge is movable between a second starting position and a second actuation position. A coupling device is switchable between a locking state, in which the valve bridge is movable out of the second starting position into the second actuation position via the coupling device by the tilting lever, and an unlocking state, in which, despite a movement of the tilting lever out of the first starting position into the first actuation position, there is no movement of the valve bridge out of the second starting position into the second actuation position. The coupling device is held on the tilting lever such that the coupling device is pivotable with the tilting lever.

A valve actuation system comprises a valve actuation motion source configured to provide main and auxiliary valve actuation motions for actuating at least one engine valve via a valve actuation load path. A lost motion subtracting mechanism is arranged in a valve bridge and configured, in a first default operating state, to convey at least the main valve actuation motion and configured, in a first activated state, to lose the main valve actuation motion and the auxiliary valve actuation motion. Additionally, a lost motion adding mechanism is arranged in a rocker arm and configured, in a second default operating state, to lose the auxiliary valve actuation motion and configured, in a second activated state, to convey the auxiliary valve actuation motion, wherein the lost motion adding mechanism is parallel with the lost motion subtracting mechanism in the valve actuation load path at least during the second activated state.

A switching rocker arm comprises an outer arm having a pair of integrally formed axles extending outwardly therefrom and an inner arm pivotally secured to the outer arm. A is latch slidably connected to the outer arm and is configured to selectively extend to engage the inner arm. An inner roller is configured on the inner arm, and a pair of outer rollers is mounted on the respective integrally formed axles on the outer arm. A rocker arm for variable valve lift comprises an outer arm comprising outer arm portions, rollers mounted in a cantilevered manner to the outer arm portions, and an inner arm seated between the outer arm portions, the inner arm comprising an inner roller. A pivot axle connects the outer arm and the inner arm. The inner arm and the outer arm are pivotable with respect to one another about the pivot axle.