Hydraulic valve with pressure limiter function
AssigneeDanfoss Power Solutions II Technology A/S
InventorsMahesh K. Jadhav, Nilesh Anant Sutar, Muzammil Qayyumoddin Quazi
Life of this patent
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Abstract
A hydraulic system includes first and second valve assemblies connected to a common pump. The first valve assembly includes a main valve housed inside a manifold. A pressure compensator valve maintains a constant pressure drop across a variable orifice of the main valve. A pressure limiter valve is in communication with the main valve and the pressure compensator valve, and allows an actuator connected to the first valve assembly to operate independently of the second valve assembly so that fluid flow to a work port of the first valve assembly is not interrupted by operation of the second valve assembly.
Claims20
A valve assembly for connecting to a pump having load sensing functionality, the valve assembly comprising:
- a main valve having a variable orifice;
- a pressure compensator valve adapted to maintain a constant pressure drop across the variable orifice and to communicate fluid from the variable orifice to a work port;
- and
- a pressure limiter valve in communication with the main valve and the pressure compensator valve, the pressure limiter valve being biased by a threshold relief pressure and having a pilot surface that receives a local load sense pressure from the work port, wherein the pressure limiter valve drains fluid from the pressure compensator valve to tank when the local load sense pressure overcomes the threshold relief pressure of the pressure limiter valve.
A hydraulic system comprising:
- a pump;
- a load sensing compensator mounted to the pump;
- a first valve assembly connected to the pump and to a first actuator via a work port, the first valve assembly adapted to communicate a first load sense pressure to the load sensing compensator, the first valve assembling including:
- a pressure limiter valve being biased by a first threshold relief pressure, and including a pilot surface that receives the first load sense pressure from the work port, wherein the pressure limiter valve drains to tank fluid from a pressure compensator valve connected to the work port when the first load sense pressure overcomes the threshold relief pressure;
- a second valve assembly connected to the pump and to a second actuator, the second valve assembly adapted to communicate a second load sense pressure to the load sensing compensator, the second valve assembly including:
- a pressure relief valve being biased by a second threshold relief pressure;
- wherein flow to the work port of the first valve assembly is maintained when the second load sense pressure is higher than the first load sense pressure.
A hydraulic system for connecting to a pump having load sensing functionality, the hydraulic system comprising:
- a first valve assembly connectable to the pump and to a first actuator, the first valve assembly adapted to communicate a first load sense pressure to a load sensing compensator mounted to the pump;
- a second valve assembly connectable to the pump and to a second actuator, the second valve assembly adapted to communicate a second load sense pressure to the load sensing compensator mounted to the pump;
- and
- a pressure limiter valve having a pilot surface that receives a local load sense pressure from a work port of the first valve assembly, wherein the pressure limiter valve maintains flow to the work port of the first valve assembly when the first valve assembly operates under a lower load sense pressure than the second valve assembly.
Dependencies are inferred from the claim text.