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 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: A method of providing diagnostic information for an electromagnetic latch assembly (122) includes providing a pulse to a circuit (200) that include one or more electromagnetic latch assemblies. The circuit (200) includes coils (199) of the electromagnetic latch assemblies. Each coil is inductively coupled with an armature (131) that is mechanically coupled to a latch pin (118). The circuit (200) is pulsed and a DC current in the circuit (200) that results from the pulse is measured over a first interval to determine a primary response. The current in the circuit (200) over a second interval is measured to determine a reference response. A second pulse may be used to generate the current for the reference response. The primary response and the reference response are compared to provide diagnostic information relating to position or movement of one or more of the latch pins (118).

Abstract: A valvetrain includes a rocker arm assembly having a rocker arm and an electromagnetic latch assembly. An electromagnet of the latch assembly is housed within a chamber formed by the rocker arm. Passageways suitable for oil cooling of the electromagnet are formed through and inside the rocker arm. In some embodiments, oil for cooling is supplied through a pivot. In some embodiments, oil for cooling is obtained from oil splash. Oil cooling may allow modes of operation such as of dynamic cylinder deactivation and dynamic variable valve actuation to be used without overheating the electromagnet.

Abstract: A valvetrain includes a camshaft (501), a pivot (303), a rocker arm assembly (203) mounted on the pivot (303), a latch assembly (122), a power transfer module (100) a rocker arm (401), a cam follower (301) configured to engage a cam, and two contacts pin (403) protruding to opposite sides of the rocker arm (401). The electromagnetic latch assembly (122) includes a latch pin (405) and an electromagnet (119) that is powered through at least one of the contact pins (403). The power transfer module (100) includes a framework (101) that supports two contact pad each contacting a respective one of the contact pins. The framework (101) has a base that abuts the pivot (303). The contact pads extend upward from the base and terminates at a height that is below a height of the rocker arm assembly (203) above the pivot (303).

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 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 method for engine braking on a type III valvetrain diesel engine comprises, on a first downstroke of a reciprocating piston, deactivating a normal intake lift profile on a first intake valve to implement a deactivated intake profile. Before a first upstroke of the reciprocating piston completes, a late intake valve closing lift profile is actuating on a second intake valve and beginning an engine brake lift profile on a first exhaust valve. On a second downstroke of the reciprocating piston, the engine brake lift profile on the first exhaust valve is completing and a normal exhaust lift profile is deactivating on a second exhaust valve to implement a deactivated exhaust profile on the second exhaust valve. Before a second upstroke of the reciprocating piston completes, a second engine brake lift profile is beginning on the first exhaust valve.

Abstract: A valvetrain includes a rocker arm assembly basing a rocker arm and an electromagnetic latch assembly. An electromagnet of the latch assembly is housed within a chamber formed by the rocker arm. Passageways suitable for oil cooling of the electromagnet are formed through and inside the rocker arm. In some embodiments, oil for cooling is supplied through a pivot. In some embodiments, oil for cooling is obtained from oil splash. Oil cooling may allow modes of operation such as of dynamic cylinder deactivation and dynamic variable valve actuation to be used without overheating the electromagnet.

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: A method of providing diagnostic information for an electromagnetic latch assembly (122) includes providing a pulse to a circuit (200) that include one or more electromagnetic latch assemblies. The circuit (200) includes coils (199) of the electromagnetic latch assemblies. Each coil is inductively coupled with an armature (131) that is mechanically coupled to a latch pin (118). The circuit (200) is pulsed and a DC current in the circuit (200) that results from the pulse is measured over a first interval to determine a primary response. The current in the circuit (200) over a second interval is measured to determine a reference response. A second pulse may be used to generate the current for the reference response. The primary response and the reference response are compared to provide diagnostic information relating to position or movement of one or more of the latch pins (118).

Abstract: A valvetrain suitable for an internal combustion engine of a type that includes a combustion chamber, a moveable valve having a seat formed within the combustion chamber, and a camshaft. The valvetrain includes a rocker arm assembly having a rocker arm and an electrical device that either configures the rocker arm assembly or provides position feedback for a part of the rocker arm assembly. The valvetrain includes a framework that fits around a spark plug tube while holding a component of a circuit that includes the electrical device in a position adjacent the rocker arm assembly. The position may place the component in contact with or very close to the rocker arm assembly. This framework structure may effectively utilize the available space under a valve cover while facilitating correct positioning of the component in relation to 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: 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 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 method for engine braking on a type III valvetrain diesel engine comprises, on a first downstroke of a reciprocating piston, deactivating a normal intake lift profile on a first intake valve to implement a deactivated intake profile. Before a first upstroke of the reciprocating piston completes, a late intake valve closing lift profile is actuating on a second intake valve and beginning an engine brake lift profile on a first exhaust valve. On a second downstroke of the reciprocating piston, the engine brake lift profile on the first exhaust valve is completing and a normal exhaust lift profile is deactivating on a second exhaust valve to implement a deactivated exhaust profile on the second exhaust valve. Before a second upstroke of the reciprocating piston completes, a second engine brake lift profile is beginning on the first exhaust valve.

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 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: An internal combustion engine 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. Therefore, the rocker arm is able to move independently from the electromagnet. The electromagnet is operative to cause the latch pin to actuate through magnetic flux following a magnetic circuit that passes through the rocker arm. Mounting the electromagnet apart from the rocker arm allows wires powering the electromagnet to be held in relatively static positions. The magnetic circuit is arranged to bring magnetic flux into the latch pin, or a co-acting part, within the volume of the rocker arm. This enables a compact design that is suitable for installation in engines where the available space under the valve cover may be very limited.