Patent ID: 6550433
Filing Date: 2003-04-22
Classification: F01L

Abstract:
A hydraulic valve actuator for operating an engine valve comprising:an actuator housing; an actuator piston having upper and lower ends, wherein said piston is reciprocally disposed within said housing and is adapted to be moved upward and downward in response to hydraulic pressure; said lower end of said actuator piston is operatively connected to the engine valve so that the engine valve opens when said actuator piston is displaced downward in response to hydraulic pressure upon said upper end, and when the hydraulic pressure is removed from said upper end said actuator piston returns upward and the engine valve shuts, said actuator piston further comprising: a pin; a pin body; and a piston body; wherein said pin is reciprocally disposed within said pin body and said pin body is disposed within and fixed to said piston body, and said piston body is reciprocally disposed within said housing; a feed and drain passage in said housing to allow hydraulic fluid to move to and from said upper end of said actuator piston; and a control element disposed within said actuator housing, wherein said control element provides a restriction in hydraulic fluid flow during a portion of the return stroke of said actuator piston thereby limiting the velocity of the actuator piston, wherein said actuator piston includes longitudinal and transverse passages which allow fluid to move from said feed and drain passage to the upper end of said piston.