US Patent 7963259 Hydro-mechanical valve actuation system for split-cycle engine

A hydro-mechanical system is disclosed for actuating an outwardly opening valve of an engine, such as a crossover passage valve of a split-cycle engine. A developed embodiment includes a body having a plunger cylinder in hydraulic fluid communication with a valve cylinder. A plunger in the plunger cylinder is reciprocated to displace hydraulic fluid into the valve cylinder, the engine valve being opened by the hydraulic fluid displaced by the plunger into the valve cylinder and acting against the valve piston. A valve spring, preferably an air spring returns the engine valve to engage an outwardly facing valve seat to close a gas passage of the engine. Control valves and an energy reusing accumulator, along with valve seating control and lift brake features may also be included.