Valve Assembly Sealing Structure to Reduce Dynamic Gas Force on Needle
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Solution Overview
Problem
The existing valve assemblies face issues where the valve needle assembly is lifted up by high-pressure airflow, preventing the valve port from closing due to dynamic gas forces, leading to instability and potential failure.
Innovation Solution
The valve assembly incorporates an annular recess in the valve seat or needle assembly, with a sealing structure having a diameter smaller than the annular sealing portion, counteracting the dynamic gas force by exerting an opposing force on the valve needle, and includes features like annular recesses, sealing circles and rings, and balance channels to stabilize the valve needle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the valve port is throttled at small opening, then the high-pressure airflow cannot be converted into low-pressure airflow within a short time, but the high-pressure airflow impacts the valve needle assembly and subjects it to great dynamic gas force, causing the valve needle assembly to be lifted up and unable to close the valve port
Solution Approach 1:
The patent introduces a balance channel that allows high-pressure airflow to act on the balance surface of the valve needle assembly, generating a counterbalancing force that opposes the dynamic gas force lifting the valve needle. This counterforce mechanism enables the valve needle to remain stable and properly close the valve port even under high-pressure conditions.
Solution Approach 2:
The patent adds a balance channel as a new flow path dimension, allowing pressure balancing to occur through a separate channel rather than relying solely on the main valve port geometry. This dimensional addition enables independent pressure control on different surfaces of the valve needle assembly.
2Reliability
If a sealing structure is added between the valve seat assembly and valve needle assembly, then sealing reliability is improved, but the device complexity increases
Solution Approach 1:
The patent integrates the sealing structure directly into the balance channel system, combining the sealing function with the pressure balancing function. The sealing structure is positioned within the balance channel pathway, allowing both sealing and pressure balancing to be achieved through a unified structural arrangement rather than separate components.
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 effectively reduces dynamic gas forces on the valve needle, ensuring it can close the valve port reliably, enhances sealing reliability, and maintains stability even under high-pressure conditions.
Implementation Method 1
the sealing circle exerts elastic pre-tightening force towards the valve needle assembly on the sealing ring
Implementation Method 2
a cavity between the nut assembly and the valve tube communicates with the valve port through the balance channel
Data Source
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AI summary
Provided is a valve assembly. The valve assembly includes a valve seat assembly (100), a valve needle assembly (200), and a sealing structure (300), where an end of the valve seat assembly (100) is provided with a valve port (101); an inner circle of the sealing structure (300) becomes a sealing ring line in sealing fit with the valve needle assembly (200), or an outer circle of the sealing structure (300) becomes a sealing ring line in sealing fit with the valve seat assembly (100); and a diameter of the sealing ring line is less than a maximum diameter of an annular sealing portion (108) between the valve needle assembly (200) and the valve port (101), and at a position between the sealing ring line and the annular sealing portion, an action force of a fluid in the valve seat assembly on a side surface of the valve needle assembly is towards the valve port, and the fluid exerts an action force towards the valve port on the valve needle assembly. In this way, an impact force on an end portion of the valve needle assembly when a valve is opened is reduced, impact of the fluid on the end portion of the valve needle assembly is weakened, stability when the valve is opened is improved, and stability of flow change is improved. An electronic expansion valve using the valve assembly is further provided.