Valve assembly
AssigneeLuk Fahrzeug-Hydraulik GmbH & Co. KG
InventorsVan Doan Nguyen, Yuejin Gong, Randolf Kortge, Hans-Jurgen Lauth, Gerhard Overdiek, Willi Parsch, Thomas Nied-Menninger
Life of this patent
Estimating the term…
Abstract
A valve assembly for controlling volume flow from a discharge device to an actuator and including a discharge throttle, and a flow control valve for controlling flow through the throttle and having a piston, and end portion of which overlaps a channel for returning excess fluid to a suction side of the discharge device and has an end region forming a seated valve preventing leakage past the end region, when the end region completely overlaps the return channel.
Claims21
A valve assembly for controlling a volume flow to hydraulic actuator from a hydraulic discharge device including a housing and a return channel formed in the housing for returning an excess fluid volume to a suction side of the discharge device, said valve assembly comprising:
- a discharge throttle;
- and
- a flow control valve for controlling fluid flow through said discharge throttle, said flow control valve including:
- a valve piston displaceable in a first bore, which is formed in the discharge device housing and intersects the return channel, between a first position, in which the fluid flow through said discharge throttle is at its maximum, and a second position, in which the fluid flow through said discharge throttle is reduced, said valve piston having an end portion, which completely overlaps the return channel in the first position of said piston and which has an end region defining at least partially a seated valve substantially eliminating leakage of pressure fluid past said end portion into the return channel;
- spring means for biasing said piston to the first position thereof;
- and
- an annular valve seat forming, with said end region, said seated valve and having a sealing edge, and wherein said end region is conical and has an outer surface engageable by said sealing edge, said annular valve seat having an inner surface defining together with said outer surface an annular space, and said inner surface and said outer surface extending parallel to each other.
A valve assembly for controlling a volume flow to hydraulic actuator from a hydraulic discharge device including a housing and a return channel formed in the housing for returning an excess fluid volume to a suction side of the discharge device, said valve assembly comprising:
- a discharge throttle;
- and
- a flow control valve for controlling fluid flow through said discharge throttle, said flow control valve including:
- a valve piston displaceable in a first bore, which is formed in the discharge device housing and intersects the return channel, between a first position, in which the fluid flow through said discharge throttle is at its maximum, and a second position, in which the fluid flow through said discharge throttle is reduced, said valve piston having an end portion, which completely overlaps the return channel in the first position of said piston and which has an end region defining at least partially a seated valve substantially eliminating leakage of pressure fluid past said end portion into the return channel;
- spring means for biasing said piston to the first position thereof;
- and
- an annular valve seat forming together with said end region, said seated valve and having a sealing edge, and wherein said end region has a conical outer surface engageable by said sealing edge.
Dependencies are inferred from the claim text.