A rocker arm can comprise a first outer arm and a second outer arm joined by a pivot body. An actuatable latch mechanism is within the pivot body. An inner arm assembly comprises a latch arm. A first spring prop is on the inner arm assembly distal from the latch arm. An axle joins the inner arm assembly to pivot between the first outer arm and the second outer arm. A spring is biased against the first outer arm and against the first spring prop. The first spring prop can comprise a hooked end. Or, the first spring prop can extend laterally out from the rocker arm and parallel to the axle. The spring can comprise a one-piece spring comprising first and second coil springs connected by a lateral connector. Or, two separate torsion springs can comprising tangential spring ends extending at approximately 90 degrees.

A type III rocker arm assembly operable in a first mode and a second mode based on rotation of a cam shaft includes a rocker shaft and a first rocker arm assembly. The first rocker arm assembly receives the rocker shaft and is configured to rotate around the rocker shaft in the first mode based on engagement with the first cam lobe. The first rocker arm assembly collectively comprises a valve side rocker arm, a cam side rocker arm and a latch pin. The valve side rocker arm defines a valve side rocker arm bore. The cam side rocker arm defines a cam side rocker arm bore. The latch pin assembly is received by the valve and cam side rocker arm bores and selectively couples the valve side rocker arm and the cam side rocker arm for concurrent movement in the first mode.

A method for advancing valve actuation during low load or idle diesel engine conditions to promote aftertreatment heat up comprises switching a cam phaser from a nominal lift position to an advance lift position to open an affiliated valve before nominal. Valve lift is actuated via the cam phaser. The valve is lowered towards nominal closure, and valve closure is interrupted by actuating a latch phaser. Valve closure is extended beyond nominal valve closure.

A latch assembly comprises a latch pin and a cage. The latch pin comprises a latch nose and a pin body. The pin body comprises an outer surface and an inner compartment. The inner compartment comprises a first inner wall segmented by a first slot and a second inner wall segmented by a second slot. The first slot and the second slot vent out of the inner compartment. The cage comprises a stepped base and a shaft extending from the stepped base into the inner compartment. The shaft comprises a first exterior flat adjoining the first inner wall and a second exterior flat adjoining the second inner wall. A spring can be biased against the latch pin and the cage. The latch assembly can be used in a latching device of a valvetrain such as a switching roller finger follower or other rocker arm.

A hydraulic lash assembly (HLA) for use in a valvetrain. The HLA preferably includes a first arm configured to transition a valve between a closed orientation and an open orientation. The first arm can include an engagement surface to receive a driving force from a timing member and to cause the valve to transition to the open orientation for a predetermined period. The HLA further preferably includes a second arm to receive a holding force from an actuator and a pivot section to couple to the first arm and displace the first arm based on the holding force from the actuator. Preferably, the first arm and the second arm form a lever arrangement whereby the pivot section of the second arm underlies and supports the first arm and allows for rotational movement of the first arm that is independent from the second arm.

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, a second arm also having a first end pivotally connected near the first end of the first arm along a pivot axle, at least one torsion spring coiled around an end of the 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 first and second arms that can detect when the arms are moving relative to each other, and adapted to provide a signal indicating the sensed movement.

A rocker arm assembly for pivoting around a rocker shaft comprises a follower side arm, a valve side arm, and a latch assembly. The follower side arm comprises a main body (1016, 2016, 3016), a rocker shaft through-bore (1061), and a follower end (11, 21, 31) comprising a latch through-bore (1019, 2019, 3019). The valve side arm comprises a forked body (1026, 2026) and a valve end (12,22) extending from the forked body. A first arm extension (1025, 2025, 3025) and a second arm extension (1028, 2028, 3028) extend from the forked body and straddle the main body. A first distal end (1125, 2125) comprises a first latch pocket (51) distal from the forked body. A second distal end (1128, 2128) comprises a second latch pocket (81) distal from the forked body. The latch through-bore selectively aligns with the first latch pocket and the second latch pocket.

A system for selectively activating and deactivating cylinders includes a first cylinder positioned in a cylinder block. A first intake or exhaust valve is coupled to the first cylinder and is actuated by a first coupling mechanism. A first oil control solenoid is coupled to the first coupling mechanism, the first oil control solenoid deactivates the first coupling mechanism to maintain the first intake or exhaust valve in a closed position. A second cylinder is positioned in the cylinder block, and a second intake or exhaust valve is coupled to the second cylinder. The second intake or exhaust valve is actuated by a second coupling mechanism. A second oil control solenoid is coupled to the second coupling mechanism, the second oil control solenoid deactivates the second coupling mechanism to maintain the second intake or exhaust valve in a closed position. The first oil control solenoid and the second oil control solenoid have different operating parameters.

Systems, devices, and methods are disclosed that during cylinder deactivation, including skipfire, at low engines speeds and low engine loads maintain adequate oil pressure of valvetrain components or hardware required for CDA and/or skipfire operation.

A rocker arm assembly can comprise a main rocker arm and a latch assembly. A latching arm can control the latch assembly and thereby control the extent to which a secondary rocker arm acts on the main rocker arm. The main rocker arm can comprise a main body configured to rotate around a rocker shaft, a valve end extending from the main body, a reaction end extending from the main body, and a latch bore. A bias pin can extend from the main body. The latch assembly can be configured to selectively rotate in the latch bore. The latch assembly can comprise a first latch end comprising a switch plate configured to receive actuation force on a first side and to receive bias force from the bias pin on a second side. A second latch end can comprise a first latch seat and a second latch seat.