Patent ID: 6135073
Filing Date: 2000-10-24
Classification: F01L

Abstract:
A hydraulic valve actuator for a poppet valve operatively associated with a high pressure fluid source and with a dual pressure source that is selectively connectable to the high pressure fluid source and to a low pressure fluid source, the actuator comprising:a high pressure conduit connected to the high pressure source;a dual pressure conduit connected to the dual pressure source;a body having a cylindrical interior surface, a generally cylindrical exterior surface and axially opposite ends;plug means for closing one of said axially opposite ends;a plunger disposed within said interior surface for movement axially of said interior surface, the plunger having one axial end disposed in the body and spaced axially from said plug means and having an opposite end axially extendable from the body;recuperation means for opening fluid communication to the high pressure conduit from within said interior surface at a recuperation location disposed axially along the interior surface between said plug means and said one axial end of the plunger when fluid pressure at said location is greater than fluid pressure in said high pressure conduit, said recuperation means includes a recuperation passage extending radially through the body at said recuperation location and includes a recuperation check valve disposed in said recuperation passage for blocking fluid flow radially inwardly of the body through the recuperation passage and for passing fluid flow radially outwardly of the body through the recuperation passage; andpassage means for providing fluid communication between said dual pressure conduit and said one axial end of the plunger, said passage means includes a closing passage extending radially through the body at a location spaced axially along said interior surface from the recuperation location toward said opposite end of the plunger, a closing check valve disposed in said closing passage for blocking fluid flow in a direction radially inwardly of the body through the closing passage and for passing fluid flow radially outwardly of the body through the closing passage, an opening passage extending radially through the body at a location spaced axially along said interior surface from the closing passage toward said opposite end of the plunger, an annular groove disposed exteriorly of the plunger for fluid communication with said opening passage at said interior surface of the body, a plunger conduit disposed in the plunger for fluid communication between said annular groove and said one axial end of the plunger, restrictor means disposed in said plunger conduit for restricting fluid flow in a direction from said one axial end toward said annular groove to a greater extent than said plunger conduit restricts fluid flow in a direction from said annular groove toward said one axial end, the dual pressure conduit communicates at said exterior surface of the body with said closing passage and with said opening passage.