Abstract: The present invention relates to methods of improving engine braking of a reciprocating piston internal combustion engine by variable valve actuation. One embodiment of the present invention enables independent two-valve actuation for each cylinder, and engine braking horsepower can be optimized using two-valve braking at high engine speeds and one-valve braking at low speeds. Another embodiment of the present invention enables better a sequential valve actuation to reduce engine braking load and compliance. Another embodiment of the present invention enables better engine starting and warming up by controlling timing and lift of each valve.

Abstract: A lost motion valve actuation system for an internal combustion engine is disclosed. The system includes a motion feedback system (100) for detecting the motion and timing of a valve actuator (130) and an engine valve (140). By providing information on the condition of the engine during operation, the motion feedback system (100) permits adjustment of the valve actuation system that can optimize operation or prevent engine damage. The motion feedback system may be used in a common rail or a lost motion valve actuation system. In alternate embodiments, the valve actuation system includes an accumulator (300) with an accumulator piston (310) whose motion is limited by an accumulator stop (330) or a control valve (200). The limited accumulator (300) controls the amount of lost motion in the valve actuation system to provide fail-safe operation in the event of electrical failure.

Abstract: The present invention is directed to a start-up system for an engine valve actuation assembly. The start-up system may comprise a removal assembly for removing at least one of air and debris from the engine valve actuation assembly during an engine start up operation. The removal assembly may include a supply assembly for supplying fluid to the engine valve actuation assembly under high pressure to remove at least one of air and debris from the engine valve actuation assembly. The supply assembly may include a storage assembly for storing a supply of hydraulic fluid, and a fluid supply assembly for supplying fluid to the storage assembly. The fluid may be supplied under pressure from the storage assembly to the engine valve actuation assembly. Furthermore, the fluid may be supplied under an influence of gravity from the storage assembly to the engine valve actuation assembly.