Abstract: A rocker arm assembly that includes an electromagnetic latch assembly with a latch pin and an actuator operative to actuate the latch pin between a first position and a second position. The actuator includes an electromagnet powered through a coil circuit. The rocker arm assembly further includes a switch in a switch circuit. The coil circuit and the switch circuit are connected in parallel. Moving the latch pin between the first position and the second position opens and closes the switch. In an alternate embodiment, relative motion of two rocker arms opens and closes the switch. The rocker arm assembly allows OBD information to be obtained without making electrical connections to the rocker arm assembly other than ones provided to power the electromagnet.

Abstract: In an electromagnetic latch assembly of a type that includes an armature, an electromagnet operative to actuate the armature, a latch pin, and a rigid metal structure that supports both the electromagnet and the latch pin, the latch pin is attached to the armature through a bendable connection. The electromagnet may be mounted to or housed within the metal structure. The latch pin may protrude from the rigid metal structure and may be guided by the metal structure. The bendable connection couples translation of the armature to translation of the latch pin while allowing the two parts to move independently to some degree. The bendable connection may reduce forces on the armature that could cause the armature to bend or stick. Those forces may result from misalignment between the latch pin and the armature or from the latch pin being driven off axis under load.

Abstract: A rocker arm assembly constructed in accordance to one example of the present disclosure includes an outer rocker arm and an inner rocker arm. The outer rocker arm has a first roller configuration that rotates around a first axis. The inner rocker arm has a second roller configuration that rotates around a second axis. The inner rocker arm is configured to move between a latched and unlatched position relative to the outer rocker arm. One of the first and second axes is positioned for alignment over an engine valve. The other of the first and second axes is offset from the engine valve.

Abstract: An engine comprises a plurality of rotating eccentric cams on a cam rail, a valve train mechanism, and respective followers wherein at least one of the respective followers has a respective first end in contact with a respective rotating eccentric cam and a respective second end in contact with the valve train mechanism, a body extending between the first end and the second end, and a follower fluid port. The engine further comprises an oil gallery bore parallel to the cam rail wherein the oil gallery bore is configured to supply oil to the respective follower through its fluid port. The engine further comprises a gallery insert placed in the oil gallery bore and is configured to abut the respective follower to prevent axial rotation with respect to the cam rail. The engine further comprises a gallery insert abut a flat surface of a follower to prevent axial rotation.

Abstract: 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.

Abstract: A valvetrain for an internal combustion engine of the type that has a combustion chamber, a moveable valve having a seat formed in the combustion chamber, and a camshaft includes a rocker arm assembly, a pivot providing a fulcrum for a rocker arm of the rocker arm assembly, and a latch assembly. An electrical device mounted to the rocker arm assembly receives power or communicates through a circuit that includes an electrical connection formed by abutment between surfaces of two distinct parts. The rocker arm assembly is operative to move one of the two abutting surfaces relative to the other in response to actuation of the cam follower. Forming an electrical connection through abutting surfaces that are free to undergo relative motion may reduce or eliminate the need to run wires to a mobile portion of the rocker arm assembly.

Abstract: 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.

Abstract: A valvetrain for an internal combustion engine of the type that has a combustion chamber, a moveable valve having a seat formed in the combustion chamber, and a camshaft includes a rocker arm assembly, a pivot providing a fulcrum for a rocker arm of the rocker arm assembly, and a latch assembly. An electrical device mounted to the rocker arm assembly receives power or communicates through a circuit that includes an electrical connection formed by abutment between surfaces of two distinct parts. The rocker arm assembly is operative to move one of the two abutting surfaces relative to the other in response to actuation of the cam follower. Forming an electrical connection through abutting surfaces that are free to undergo relative motion may reduce or eliminate the need to run wires to a mobile portion of the rocker arm assembly.

Abstract: A valvetrain for an internal combustion engine includes a camshaft and a rocker arm assembly. The rocker arm assembly includes an electrical device, a rocker arm, and a cam follower. A contact held to the rocker arm abuts a spring attached to a component distinct from the rocker arm assembly to form an interface. The electrical device is powered through the interface. The spring slides over the contact as the rocker arm assembly pivots to actuate a moveable valve. The interface is formed near a pivot axis whereby the motion undergone by the interface is much less than the motion undergone by points on the rocker arm assembly more distal from the axis. Keeping the interface proximate the pivot axis and leaving the spring free to slide over the contact reducing the extent to which the spring undergoes movement and wear during valvetrain operation.

Abstract: A valvetrain includes a rocker arm assembly having a rocker arm and an electromagnetic latch assembly. A magnet of the latch assembly is housed within a chamber formed by the rocker arm. The chamber may be a retrofit hydraulic chamber. The magnet may be an electromagnet or a permanent magnet. A flux shifting bi-stable latch provides a sufficiently compact design. Isolation of the magnet within the rocker arm chamber may provide protection from metal particles carried by oil in an operating environment for the rocker arm assembly.

Abstract: A method of operating an internal combustion engine that includes a valvetrain having a rocker arm assembly including a rocker arm on which a latch pin is mounted. An actuator for the latch pin, including an electromagnet, is mounted separately from the rocker arm. Rocker arm position information is obtained by gathering and analyzing data relating to a current or voltage in an electrical circuit that is operative to power the electromagnet. The rocker arm position information is used to perform a diagnostic.

Abstract: A method of operating an internal combustion engine of a type that has a combustion chamber, a moveable valve having a seat formed in the combustion chamber, a camshaft on which a cam is mounted, and a rocker arm assembly having a rocker arm and a cam follower configured to engage the cam as the camshaft rotates. The method includes obtaining rocker arm position data, using the rocker arm position data to obtain camshaft position information, and using the camshaft position information in an engine management operation.

Abstract: 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.

Abstract: A valvetrain for an internal combustion engine includes a camshaft and a rocker arm assembly. The rocker arm assembly includes an electrical device, a rocker arm, and a cam follower. A contact held to the rocker arm abuts a spring attached to a component distinct from the rocker arm assembly to form an interface. The electrical device is powered through the interface. The spring slides over the contact as the rocker arm assembly pivots to actuate a moveable valve. The interface is formed near a pivot axis whereby the motion undergone by the interface is much less than the motion undergone by points on the rocker arm assembly more distal from the axis. Keeping the interface proximate the pivot axis and leaving the spring free to slide over the contact reducing the extent to which the spring undergoes movement and wear during valvetrain operation.

Abstract: A method for exhaust temperature management in a multiple-cylinder, reciprocating-piston engine, comprising sensing a low temperature condition of the exhaust and implementing an increased heat output engine cycle pattern for the engine based on the sensed low temperature condition. The increased heat output engine cycle pattern comprises deactivating fuel injection to a first cylinder of the engine, the first cylinder comprising a piston reciprocating between top-dead-center and bottom-dead-center. Also, activating engine braking mode on the first cylinder by opening one or more valves when the piston is away from bottom-dead-center during a compression stroke. A second cylinder of the engine is fired in a combustion mode while the first cylinder is in engine braking mode.

Abstract: A valvetrain for an internal combustion engine of the type that has a combustion chamber, a moveable valve having a seat formed in the combustion chamber, and a camshaft includes a rocker arm assembly, a pivot providing a fulcrum for a rocker arm of the rocker arm assembly, and a latch assembly. An electrical device mounted to the rocker arm assembly receives power or communicates through a circuit that includes an electrical connection formed by abutment between surfaces of two distinct parts. The rocker arm assembly is operative to move one of the two abutting surfaces relative to the other in response to actuation of the cam follower. Forming an electrical connection through abutting surfaces that are free to undergo relative motion may reduce or eliminate the need to run wires to a mobile portion of the rocker arm assembly.

Abstract: A method of using a through axle switching rocker arm according to one example of the present disclosure is provided. The switching rocker arm comprises an outer and inner arm and a roller axle. The inner arm is pivotally coupled to the outer arm about a pivot axle and has an inner bushing that supports an inner roller. The inner bushing defines an inner diameter. The roller axle extends through the inner bushing and defines an outer diameter. The inner diameter of the inner bushing engages the outer diameter of the roller axle thereby inhibiting further pivoting of the inner arm relative to the outer arm defining a rocker arm travel constraint. The method includes designing first and second cam profiles based on the through axle switching rocker arm such that a difference in lift between the first and second cam profiles is held within the rocker arm travel constraint.

Abstract: A rocker arm comprises a first outer arm and a second outer arm joined by a pivot body, the first outer arm comprising an inner side, the inner side comprising a limiting surface. An actuatable latch mechanism is within the pivot body. A first inner arm and a second inner arm are joined by a latch arm. An axle joins the first inner arm and the second inner arm to pivot between the first outer arm and the second outer arm. A second axle is between the first inner arm and the second inner arm. A pin extends from the second axle towards the first outer arm, and the pin is configured to pivot towards and away from the limiting surface when the first inner arm and the second inner arm pivot between the first outer arm and the second outer arm.

Abstract: A method of operating an internal combustion engine that includes a valvetrain having a rocker arm assembly including a rocker arm on which a latch pin is mounted. An actuator for the latch pin, including an electromagnet, is mounted separately from the rocker arm. Rocker arm position information is obtained by gathering and analyzing data relating to a current or voltage in an electrical circuit that is operative to power the electromagnet. The rocker arm position information is used to perform a diagnostic.

Abstract: A method of operating an internal combustion engine of a type that has a combustion chamber, a moveable valve having a seat formed in the combustion chamber, a camshaft on which a cam is mounted, and a rocker arm assembly having a rocker arm and a cam follower configured to engage the cam as the camshaft rotates. The method includes obtaining rocker arm position data, using the rocker arm position data to obtain camshaft position information, and using the camshaft position information in an engine management operation.