Pressure Compensation Valve Membrane Layout for Repeatable Flow Control
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Solution Overview
Problem
Existing fluid flow control valves face challenges in miniaturization and precision due to high biasing forces required to counteract pressure differences, leading to increased size and power requirements, and are sensitive to external factors like supply pressure and flow rates, which affects their repeatability and accuracy.
Innovation Solution
A valve assembly with a pressure compensation chamber and a flexible membrane that includes a pressure compensation flow path with varying cross-sectional areas and openings between the armature and the flexible membrane, allowing for quicker transmission of pressure fluctuations and improved control accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high biasing force is used to counteract pressure differences, then the valve element remains securely closed, but the actuator size and power requirements increase
Solution Approach 1:
A pressure compensation chamber is introduced as an intermediary between the valve element and the actuator. This chamber receives compensation fluid through a compensation flow path, generating a pressure compensation force that acts on the valve element to assist the biasing member. The compensation force reduces the burden on the actuator, allowing smaller actuators to control valves with high pressure differences while maintaining reliable sealing.
Solution Approach 2:
The invention uses fluid pressure (pneumatics or hydraulics) to provide the compensation force. Compensation fluid is supplied to the pressure compensation chamber, creating a pressure that generates an upward force on the valve element. This hydraulic/pneumatic compensation mechanism reduces the mechanical burden on the actuator and biasing member, enabling miniaturization while maintaining valve control reliability under high pressure differences.
2Volume of moving object
If the valve assembly is miniaturized, then the displacement and actuating forces are reduced, but the precision and control accuracy deteriorate
Solution Approach 1:
The pressure compensation chamber acts as a mediator that stabilizes the valve element position. By supplying compensation fluid to this chamber, a controlled compensation force is generated that counteracts disturbances and maintains precise valve control. This intermediary mechanism enables miniaturized valves to achieve the same control precision as larger valves by providing active pressure compensation.
Solution Approach 2:
The invention changes the pressure parameter in the pressure compensation chamber to achieve precise control. By adjusting the compensation fluid pressure, the compensation force can be precisely controlled, allowing the valve element to be positioned accurately even in miniaturized valves. This parameter control approach maintains precision despite reduced size.
3Reliability
If the pressure compensation flow path has a large cross-sectional area, then the pressure compensation is effective, but the valve assembly size increases
Solution Approach 1:
The pressure compensation flow path is designed with locally optimized cross-sectional areas. Rather than uniformly large dimensions throughout, the flow path has varying cross-sectional areas at different locations, with larger areas where high compensation flow is needed and smaller areas where less flow is required. This local optimization provides effective pressure compensation while minimizing the overall valve assembly size.
Solution Approach 2:
The pressure compensation flow path is segmented into multiple sections with different cross-sectional areas. This segmentation allows the flow path to provide adequate compensation capacity in critical sections while having reduced dimensions in other sections, thereby achieving effective pressure compensation without proportionally increasing the overall valve assembly volume.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables more precise and repeatable operation of the valve by reducing friction, minimizing the size and energy requirements of the actuator, and enhancing the control accuracy by optimizing the pressure compensation flow path, making it suitable for precision applications like micro-fluidic valves.
Implementation Method 1
a flexible membrane which forms a seal against the moveable member and the valve body to divide the valve chamber into a flow chamber in which the valve seat and valve element are located and a pressure compensation chamber within which the armature is entirely enclosed
Implementation Method 2
A solenoid may be used to generate a magnetic field which can exert a magnetic force on a moveable member to provide opening, closing and/or switching of the valve
Implementation Method 3
Such valves typically include a biasing member that generates a biasing force to oppose the magnetic force. Therefore, in the absence of a magnetic field from the solenoid, the biasing force maintains the valve in a normally open or normally closed position
Data Source
AI summary
A valve assembly is disclosed, which includes a valve body defining a valve chamber and a moveable member. The moveable member has a valve element at its first end and an armature at its second end. The moveable member is moveable in an axial direction to selectively open and close the valve. The entire moveable member is spaced from the walls of the valve body when the valve is open or partially open. A flexible membrane forms a seal against the moveable member and the valve body to divide the valve chamber into a flow chamber in which the valve seat and valve element are located and a pressure compensation chamber within which the armature is entirely enclosed. A first fluid port is fluidly connected to the pressure compensation chamber via one or more bores in a pressure compensation flow path with at least one opening extending into the pressure compensation chamber at an axial position between the armature and the flexible membrane. The pressure compensation flow path includes a first axial portion with a first cross-sectional area and a second axial portion with a second, smaller cross-sectional area.