Patent ID: 6776129
Filing Date: 2004-08-17
Classification: F01L

Abstract:
A hydraulic actuator for a gas exchange valve of an internal combustion engine, comprisinga cylinder bore (3), a piston (9), an annular piston (7), the piston (9) and the annular piston (7) being guided in the cylinder bore (3); the piston (9), annular piston (7) and cylinder bore (3) defining a first chamber (13) in the axial direction whose volume increases when the actuator (1) opens the gas exchange valve (23), the annular piston (7) and the cylinder bore (3) defining a second chamber (27) in the axial direction whose volume decreases when the actuator (1) opens the gas exchange valve (23); the piston (9) and the cylinder bore (3) defining a third chamber (25) whose volume decreases when the actuator (1) opens the gas exchange valve (23), and a device for limiting the volumetric decrease of the second chamber (27).