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 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.