Compact lost motion system for variable valve actuation

A system for providing engine valves with variable valve actuation for engine valve events, said system comprising:

• a housing having a master piston bore and a slave piston bore;
• a master piston slidably disposed in the master piston bore;
• a cam operatively connected to the master piston, said cam dedicated to operation of the master piston;
• a slave piston slidably disposed in the slave piston bore, wherein the slave piston is selectively hydraulically linked to the master piston and adapted to actuate one or more engine valves;
• a valve seating assembly incorporated into the slave piston;
• and
• a trigger valve operatively connected to the slave piston bore.

A lost motion valve actuation system comprising:

• a housing having a master piston bore and a slave piston bore, wherein the master piston bore and the slave piston bore extend axially in directions substantially perpendicular to each other;
• a master piston slidably disposed in the master piston bore, wherein the master piston is adapted to receive an input motion;
• and
• a slave piston slidably disposed in the slave piston bore, wherein the slave piston is adapted to actuate one or more engine valves.

A method of providing variable valve actuation for an internal combustion engine valve using a slave piston hydraulically linked to a master piston for all non-failure mode valve actuations carried out by the engine valve, said method comprising the steps for:

• displacing the master piston in a master piston bore responsive to a cam motion;
• providing hydraulic fluid to a slave piston bore directly from the master piston bore responsive to displacement of the master piston;
• displacing the slave piston in the slave piston bore responsive to the provision of hydraulic fluid to the slave piston bore;
• actuating the engine valve responsive to displacement of the slave piston;
• and
• selectively releasing hydraulic fluid from and adding hydraulic fluid to the slave piston bore to achieve variable valve actuation.