Check Valve Seal Arrangement With O-Ring Piston Groove
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional check valves used in refrigerant systems, which rely on flat gasket materials for sealing, face challenges in cost and reliability, particularly in ensuring one-way refrigerant flow and maintaining an effective seal.
Innovation Solution
A sealing arrangement featuring a piston member with a circular groove and an O-ring, where the groove flares from a narrower opening width to a wider base width, and a biasing member like a coil spring to ensure the O-ring engages with the housing sealing surface, allowing for reliable one-way flow control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flat gasket material is used for sealing in check valves, then the structure is simple and cost is low, but the reliability of sealing is insufficient
Solution Approach 1:
The patent employs an O-ring made of flexible elastomeric material as the sealing element. This flexible ring can deform to conform to the sealing surface irregularities, providing reliable sealing compared to rigid flat gaskets. The O-ring is mounted in a groove on the piston member, allowing it to maintain continuous contact with the sealing surface throughout the valve's operational cycle.
Solution Approach 2:
The patent uses a circular groove with a curved cross-section to house the O-ring. This curved geometry allows the O-ring to be properly seated and compressed against the sealing surface. The circular shape of the groove provides uniform stress distribution on the O-ring, enhancing its sealing effectiveness compared to flat or angular groove designs.
2Reliability
If flat gasket material is used for sealing, then manufacturing is simple, but the seal effectiveness and flow control reliability are compromised
Solution Approach 1:
The flexible O-ring provides consistent sealing performance that ensures reliable flow control in one direction. Its ability to deform and maintain contact with the sealing surface compensates for minor manufacturing tolerances, achieving reliable flow control without requiring extremely precise manufacturing of the sealing surfaces themselves.
Solution Approach 2:
The O-ring acts as an intermediary sealing element between the piston member and the valve body sealing surface. This intermediate component absorbs manufacturing variations and provides a consistent sealing interface, making the overall system more manufacturable while maintaining flow control reliability.
3Reliability
If a groove with flared shape is used for the O-ring, then the O-ring retention is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The flared groove design with curved surfaces provides natural retention for the O-ring through geometric interlocking. The gradual expansion of the groove from the sealing face inward creates a mechanical lock that prevents the O-ring from dislodging during operation, significantly improving retention reliability.
Solution Approach 2:
The groove dimensions are designed with specific parameters including the flare angle and depth-to-width ratio. By optimizing these geometric parameters, the design achieves reliable O-ring retention while keeping manufacturing precision requirements within practical limits. The flare angle is sufficient to provide retention but not so steep as to create excessive manufacturing difficulty.
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 described sealing arrangement enhances the reliability and cost-effectiveness of check valves by ensuring a secure seal when needed and allowing fluid passage when required, improving the overall performance of refrigerant systems.
Implementation Method 1
an O-ring disposed in the groove
Implementation Method 2
a biasing member in engagement with the housing and the piston member so as to exert a biasing force on the piston
Data Source
AI summary
A check valve includes a housing defining an inlet, an outlet, a passage between the inlet and outlet, and a sealing surface along the passage. A piston member is disposed about a longitudinal axis and has a sealing face disposed perpendicular to the longitudinal axis and a circular groove defined therein extending inward from the sealing face. An O-ring is disposed in the groove. A biasing member exerts a biasing force on the piston and thus forces the O-ring into sealing engagement with the sealing surface of the housing. The piston member is moveable from a first position in which the O-ring is sealingly engaged with the sealing surface of the housing and thus the outlet is sealed from the inlet, and a second position in which the O-ring is spaced from the sealing surface of the housing and thus the outlet is not sealed from the inlet.