Abstract: A hydraulic valve actuation system (30) and a method of assembly can include a plurality of hydraulically actuatable valves (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) operably associated with an internal combustion engine (86) having a crankshaft (50) rotatable about a longitudinal axis. The actuation system (30) can include at least one cam lobe (52) mounted on or integrally formed with the crankshaft for rotation with the crankshaft (50). At least one fluid piston pump (36, 36a, 36b) connected to the at least one cam lobe (52) for generating a reciprocating fluid flow in response to rotation of the at least one cam lobe (52). At least one hydraulically actuated valve (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) in fluid communication with the reciprocal fluid flow generated by the at least one fluid piston pump (36, 36a, 36b) to drive the valve (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) to be controlled toward an open position.

Abstract: A crankshaft driven valve actuation system (30), and methods of operation and assembly, for controlling opening and closing at least one hydraulically actuated engine valve (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) associated with a cylinder of an internal combustion engine can include a crankshaft (50) driven by the engine, at least one fluid piston pump (36a, 36b) mounted for rotation on the crankshaft (50) for generating a reciprocating fluid flow in response to rotation of the crankshaft (50), a fluid passage providing fluid communication of the reciprocating fluid flow with one of the at least one hydraulically actuated valves to be controlled, and at least one control valve (56a, 56b, 56c, 56d) providing fluid flow between at least one accumulator (46, 46a, 46b, 46c, 46d) and the at least one fluid piston pump (36a, 36b) for modifying a valve timing actuation curve of the hydraulically actuated engine valve (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) during reciprocal fluid flow.