A method of operating a rocker arm assembly in a cylinder deactivation mode according to one example of the present disclosure includes providing a two-step variable valve lift rocker arm assembly and a deactivating lash adjuster. Operation of the rocker arm assembly in cylinder deactivation mode is selected. The rocker arm assembly is operated in low-lift mode based on the selection of the cylinder deactivation mode. Subsequent to or concurrently with operating the rocker arm assembly in the low-lit mode, the deactivating lash adjuster is operated in the unlatched mode. A first amount of the total lost motion required for cylinder deactivation mode is accounted for by lost motion of the rocker arm assembly operating in the low-lift mode and a remainder amount of the total lost motion is accounted for by lost motion of the deactivating lash adjuster operating in the unlatched mode.

A method of retrofitting a rocker arm assembly for an engine includes removing a first rocker arm assembly from the engine such that a camshaft of the engine remains in the engine. The method also includes providing a second rocker arm assembly that includes a rocker shaft, a rocker arm, a pushrod, and a hydraulic lash adjuster. The rocker arm is connected to the rocker shaft such that the rocker arm can pivot relative to the rocker shaft. The rocker arm has a first end, a second end, and a first oil passage. The pushrod has a top end and a bottom end, in which the top end is connected to the second end of the rocker arm and the bottom end is configured for engaging a camshaft of the engine. The hydraulic lash adjuster includes a housing, a first body member, a second body member, a check valve, and a biasing member. The first body member is disposed in the housing such that a first radial clearance exists between an outer surface of the first body member and an inner surface of the housing. The first body member has a first bore and an opening in fluid communication with the first oil passage of the rocker arm. The second body member is disposed in the first bore of the first body member such that a second radial clearance exists between the inner surface of the first bore of the first body member and an outer surface of the second body member. The second radial clearance is less than the first radial clearance. The check valve is configured to allow oil to flow through the opening of the first body member when the check valve is in an open position and configured to prevent the flow of oil through the opening when the check valve is in the closed position. The biasing member is disposed in a second bore of the second body member. The method further includes inserting the second rocker arm assembly into the engine such that the bottom end of the pushrod engages the camshaft of the engine and the front end of the rocker arm engages a valve assembly of the engine.

An engine roller lifter for use in a leak-valvetrain of an internal combustion engine includes a body, a roller and an anti-rotation plug. The body includes an outer peripheral surface configured for sliding movement in a bore provided in the engine. The bore is supplied oil by an oil passage communicating therewith. The body defines an opening. The roller bearing is rotatably mounted to the body and is configured for rolling contact with an engine camshaft. The anti-rotation plug is received at the opening and has a plug body including an anti-rotation protrusion that extends radially beyond an outer peripheral surface of the plug body. The anti-rotation plug can be staked into the opening of the body.

Systems for valve actuation in internal combustion engines provide configurations for hydraulic lash adjusters and valve actuation valvetrain components that are particularly suitable for prevention of HLA jacking in lost motion cam environments and in valve bridge environments. In one implementation, a rocker arm may transmit motion from a lost motion cam having main event and auxiliary event lobes. Main event motion is transmitted to two engine valves through the rocker arm, a lash adjuster, lash adjuster loading component and valve bridge, which define part of a first load path. Braking motion is transmitted to one of the engine valves through an inboard valve actuator and bridge pin, which define part of a second load path. The HLA is thus disposed in a separate load path from the braking valve load and the lash adjuster loading component keeps the lash adjuster under a constant compressive force to prevent jacking.

A rocker arm includes an outer arm with an outer follower and an inner arm which selectively pivots relative to the outer arm, the inner arm having an inner follower. A lost motion spring biases the inner arm to pivot relative to the outer arm. A lock pin which slides between a coupled position and a decoupled position. A pivot shaft includes a first portion a second portion centered about a first pivot shaft axis and a third portion located between the first portion and the second portion that is centered about a second pivot shaft axis which is parallel to, and laterally offset from, the first pivot shaft axis. The third portion supports the inner arm.

A rocker arm includes an outer arm with an outer follower and an inner arm which selectively pivots relative to the outer arm, the inner arm having an inner follower. A lost motion spring biases the inner arm to pivot relative to the outer arm. A lock pin which slides between a coupled position and a decoupled position. A pivot shaft includes a first portion a second portion centered about a first pivot shaft axis and a third portion located between the first portion and the second portion that is centered about a second pivot shaft axis which is parallel to, and laterally offset from, the first pivot shaft axis. The third portion supports the inner arm.

A valve train assembly for an internal combustion engine includes: a dual body rocker arm for controlling a valve of a cylinder, the rocker arm including a first body, a second body mounted for pivotal motion with respect to the first body, a first biasing means, and a latch pin moveable between a first position in which the latch pin latches the first body and the second body together and a second position in which the first body and the second body are un-latched to allow pivotal motion of the second body relative to the first body; and an actuator arrangement external to the dual body rocker arm and drivable by an actuation source, the actuator arrangement moving the latch pin from one of the first position and the second position to the other of the first position to the second position.

A hydraulic lash adjuster assembly constructed in accordance to one example of the present disclosure includes a bucket and a hydraulic lash adjuster. The hydraulic lash adjuster is received in the bucket and has a body, a leakdown plunger and a socket. The leakdown plunger is received in the body. The socket is received by the leakdown plunger. The socket and leakdown plunger define a reservoir therebetween. The socket includes a gravity feed arrangement to feed fluid to the reservoir of the leakdown plunger.

A rocker arm assembly constructed in accordance to one example of the present disclosure includes an outer rocker arm, a first inner rocker arm, and a second inner rocker arm. The first inner rocker arm is configured to move between a latched and unlatched position relative to the outer rocker arm. The second inner rocker arm is configured to move between a latched and unlatch position relative to the outer rocker arm. The rocker arm assembly provides at least three distinct lift profiles including (i) a first lift profile when the first inner rocker arm is latched and the second inner rocker arm is unlatched, (ii) a second lift profile when the second inner rocker arm is latched and the first inner rocker arm is unlatched, and (iii) a third lift profile when both the first and second inner rocker arms are unlatched.

A hydraulic lash adjuster for an engine valve train has a hydraulic lash adjusting arrangement for automatically compensating for lash in an engine valve train, and a lost motion arrangement for inhibiting motion induced in the valve train in response to a lift profile of a rotating cam from being transferred to an engine valve.