A two-stroke, opposed-piston engine includes a cylinder with an inlet piston controlled inlet port and an exhaust piston controlled exhaust port, the cylinder defining a combustion chamber with the inlet piston and the exhaust piston, a charge air channel in flow communication with the inlet port, a conduit extending directly from the combustion chamber to the charge air channel, and a valve arranged to selectively open and close flow communication through the conduit.

Multiple tubular members 40 that include multiple cam members 41 and 42 having cam parts 11 are connected to each other to form a single cam tube 12. Multiple female splines 45, which are partially arranged on an inner tube surface 44 of the tubular members which include the cam members 41 and 42, mate with male splines 47 formed on the outer tube surface 46 of a drive shaft 13, and the cam tube 12 rotates integrally with the drive shaft 13, and is capable of moving freely in the axial direction thereof.

A valve operating system for a multicylinder engine opens and closes a pair of valves provided on each of cylinders by means of a pair of rocker arms operated by a cam provided on a camshaft supported on a cam holder. When viewed in a direction of a cylinder axis, the pair of rocker arms of at least one of the cylinders are inclined in opposite directions to each other with respect to a direction orthogonal to a camshaft axis. Therefore, thrust loads acting on the camshaft from the pair of rocker arms are counteracted individually for each of the cylinders, thereby enabling the thrust load to be reduced and axial movement of the camshaft to be prevented.

A valvetrain includes a rocker arm assembly and a power transfer module that provides power to the rocker arm assembly. The power transfer module includes a mounting frame that positions a resilient contact to abut and slide over a corresponding contact on the rocker arm assembly thereby maintain an electrical connection to the rocker arm assembly during rocker arm assembly operation. In some embodiments the structure facilitates retention of the rocker arm assembly on a pivot. The contact on the rocker arm may be provided by a contact pin. The mounting frame may abut and/or go around a pivot for the rocker arm assembly. A contact frame on the rocker arm may hold conductors of the electrical circuit extending from the contacts.

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 method of precision manufacture of an outer arm of a rocker arm assembly is performed by determining structures of a rough outer arm that would require precision processing and locations to support the structures as they are processed. Starting with at least one structure requiring precision processing, locations on the outer arm close to the structure to hold the outer arm during processing are determined that would cause minimal distortion of the outer arm during processing. The outer arm is then provided with clamping lobes at these locations. The clamping lobes of the outer arm are clamping into a fixture for manufacturing. The slider pad may now be precision ground while the outer arm is clamped in the fixture with minimal risk of distortion of the outer arm.

A valve train assembly includes: at least one dual body rocker arm having a first body, a second body, a latching arrangement for latching and unlatching the first body and the second body, the latching arrangement having a latching pin that is biased to an unlatched configuration; and an actuator arrangement for controlling the latching arrangement, the actuator arrangement being able to contact the latching arrangement to cause the latching pin to be moved into a latched configuration in which it latches the first and second bodies together. In use, movement of the rocker arm under action of a cam to cause a valve event moves the actuator arrangement out of contact with the latching arrangement while a contact force between the latching pin and one or other of the first and second bodies maintains the latching pin in the latched configuration.

A rocker arm includes an outer arm and an inner arm which selectively pivot relative to each other. A lock pin moves between a coupled position in which the lock pin prevents the inner arm from pivoting relative to the outer arm past a predetermined in a first direction and a decoupled position in which the lock pin permits rotation past the predetermined position in the first direction. A lost motion spring biases the inner arm to pivot relative to the outer arm in a second direction which is opposite of the first direction. A travel stop extends along a travel stop axis and has a travel stop surface such that the extent to which the inner arm pivots relative to the outer arm in the second direction is dependent upon the rotational position of the travel stop about the travel stop axis.

A roller pin decoupling type cylinder deactivation (CDA) system includes a roller rocker arm, rocker shaft, a camshaft, and an actuation valve. When oil is not supplied to a rocker shaft sub passage of the rocker shaft and a hydraulic pressure is released from the actuation valve, the roller and the pin are not restrained so that the CDA is generated. Thus, the roller is switched to a non-rotating state and a rotating state according to non-operation and operation of the CDA. In particular, a degree of freedom of control over a system mechanism is imparted due to restriction control of the roller pin through the actuation valve which is operated by a hydraulic pressure, which makes it possible to improve operation efficiency for each engine operating condition.

An internal combustion engine includes a cylinder head and a valvetrain including a poppet valve, a cam shaft on which is mounted a cam, and a rocker arm assembly. The rocker arm assembly includes a rocker arm and a cam follower configured to engage the cam as the cam shaft rotates. The rocker arm assembly is operative to transmit force from the cam to actuate the valve and includes an electrical device mounted to the rocker arm. A first electrical circuit includes the electrical device and a first conductor mounted to the rocker arm and a second electrical circuit includes a second conductor mounted off the rocker arm. The first and second conductors are inductively coupled to an extent that enables effective power transfer or communication between them. Inductive power transfer avoids the use of wires that could become caught, clipped, or fatigued and consequently short out.