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 roller-lifter assembly for a cam-actuated engine, comprising a two-part roller lifter (10, 13, 16) comprising a pump actuator main body, a receiving portion extending from the main body (160, 161, 162, 163 164), and a cam follower comprising a roller assembly (31) or a flat tappet integrated to the main body and configured to follow a rotating cam of a cam-actuated (32) engine. A hydraulically-actuated capsule (200, 202, 203, 204, 205) is fitted to the receiving portion of the pump actuator, the capsule configured to rotate with respect to the pump actuator (100, 101, 102, 103, 104).

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.

A valvetrain assembly configured to selectively perform a bleeder brake operation includes a rocker arm configured to rotate about a rocker shaft, a camshaft having a lobe configured to impart motion to the rocker arm through a pushrod, and a valve bridge assembly operably associated with the rocker arm and configured to be selectively engaged by the rocker arm to open at least one of a first and second engine valve. An engine brake capsule is operably associated with the valve bridge assembly and configured to operate in a drive mode where the engine brake capsule does not cause the valve bridge assembly to open the first or second engine valves, and a brake mode where the engine brake capsule engages the valve bridge assembly to partially open the first engine valve to perform the bleeder brake operation.

An engine valve lifter assembly comprises a lifter body, a plunger assembly, and a spring. The lifter body comprises an oil control portion comprising an exterior surface, oil ports, and an interior oil chamber. A plunger interface end comprises an interior plunger chamber and a second spring seat. Selectively reciprocating plunger assembly comprises a piston end coupled to reciprocate in the oil chamber and a cam input end comprising a spring seat. A spring is biased between the spring seat and the second spring seat. The spring is configured to push the cam input end away from the plunger chamber. A sleeve is coupled around the oil control portion of the lifter body, and the sleeve is slidable between a lower position and an upper position to selectively block and unblock the oil ports.

Shown is a latch pin for use in a valve lifter and a valve lifter including the same. The latch pin for selectively latching within a pin chamber provided in the valve lifter is configured as a whole as a cylindrical pin with one end in the shape of a spherical crown, wherein a stepped flat is formed on radially one side of said one end and is dimensioned to be received within the pin chamber to engage with an axial latching surface thereof. On the top side of said one end, a first relief is formed by beveling the spherical crown, and on the radially other side opposite to the stepped flat across said first relief, a second relief is formed by beveling the spherical crown, wherein the second relief radially adjoins the first relief and circumferentially adjoins a remaining pin face in the shape of the spherical crown.

Provided is a tappet capable of supplying lubricating oil to a cam even when provided with a lash adjuster. A tappet (10) includes: a lash adjuster (11) having a plunger (14) and a body (13) in which the plunger (14) is housed so as to be vertically movable, wherein the plunger (14) has a top portion (16) against which a lower end portion of a push rod (88) slidably abuts; and a tappet body (12) which has an assembly hole (45) in which the body (13) is inserted, has a cup-like shape, and has a lower surface portion (27) which slidingly contacts a cam (70). The tappet body (12) has an oil guide passage (30) extending so as to guide lubricating oil from the push rod (88) side to the cam (70).

A gas engine is disclosed. The gas engine may include a combustion cylinder. The combustion cylinder may include an intake with an intake valve. The combustion cylinder may include an exhaust with an exhaust valve. The gas engine may include a gas admission valve assembly coupled to the intake. The gas admission assembly may include a trimmable electro-hydraulically actuatable gas admission valve to control a gas flow into the intake.

A roller-lifter assembly for a cam-actuated engine, comprising a two-part roller lifter (10, 13, 16) comprising a pump actuator main body, a receiving portion extending from the main body (160, 161, 162, 163 164), and a cam follower comprising a roller assembly (31) or a flat tappet integrated to the main body and configured to follow a rotating cam of a cam-actuated (32) engine. A hydraulically-actuated capsule (200, 202, 203, 204, 205) is fitted to the receiving portion of the pump actuator, the capsule configured to rotate with respect to the pump actuator (100, 101, 102, 103, 104).

In a tappet with a built-in lash adjuster, hydraulic oil is prevented from leaking from a low pressure chamber during a long-period stop. A tappet (10) includes a hydraulic lash adjuster (11) which supports a lower end portion of a push rod (96) and a tappet case (12) to which the lash adjuster (11) is internally fitted and which is reciprocally displaced in a vertical direction according to a rotating cam (85). An inner peripheral surface of the tappet case (12) is provided with an air-vent passage (34) through which air existing between the tappet case (12) and the lash adjuster (11) can be discharged upward when the lash adjuster (11) is being assembled.