Microfluidic Valve Cam Seal for Contaminant-Resistant Sealing
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Solution Overview
Problem
Ball and seat check valves and relief valves can fail due to contaminants getting stuck at the ball-seat interface, leading to leaks and damage, especially in micro valves where the diameter is less than a centimeter, as contaminants can increase the spring stiffness and create a leak path between the ball and seat.
Innovation Solution
A valve design featuring a cam with a self-energizing seal and a sloped wall, along with pistons and springs, that allows for sliding seal interfaces to selectively open or close fluid communication between the inlet and outlet, preventing contaminants from disrupting the sealing mechanism and maintaining proper alignment to prevent leaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a ball and seat interface is used for sealing, then the valve can effectively regulate pressure and control fluid flow, but contaminants can become stuck at the interface causing leaks and valve failure
Solution Approach 1:
The patent extracts the sealing function from the traditional ball-seat interface and relocates it to a dedicated seal member (O-ring or elastomeric seal) that interfaces with a seal groove in the valve body. This separation allows the sealing function to be isolated from the ball movement mechanism, preventing contaminants from interfering with the sealing interface while maintaining effective sealing performance.
Solution Approach 2:
The patent introduces a seal member (O-ring or elastomeric seal) as an intermediary element between the ball assembly and the valve body. This intermediary seal creates a dedicated sealing interface that is protected from contaminant interference, while still allowing the ball to move freely to control fluid flow and regulate pressure.
2Length of moving object
If the valve diameter is reduced to less than a centimeter for micro valve applications, then the valve becomes more suitable for compact systems, but contaminants have a proportionally greater impact on sealing and can damage the small surfaces
Solution Approach 1:
In micro valve applications, the patent extracts the sealing function from the ball surface and relocates it to a dedicated seal member that interfaces with a seal groove. This prevents contaminants from damaging the small ball surface while maintaining effective sealing in the compact valve structure.
Solution Approach 2:
The patent employs flexible elastomeric seals or O-rings that can conform to the seal groove geometry in micro valve applications. These flexible sealing elements maintain effective sealing contact despite the reduced valve dimensions and are more resistant to contaminant damage compared to rigid ball surfaces.
3Reliability
If a spring is used to bias the ball against the seat, then the valve can automatically close to prevent overpressure, but contaminants can become engaged with the spring increasing stiffness and requiring higher pressure to operate
Solution Approach 1:
The patent extracts the spring from direct contact with the ball and relocates it to bias a seal member or valve closure element. This separation prevents contaminants from engaging with the spring mechanism while maintaining automatic valve closure functionality through the spring-loaded seal.
Solution Approach 2:
The patent introduces a seal member or closure element as an intermediary between the spring and the fluid path. The spring biases this intermediary element, which in turn maintains sealing contact or controls valve closure, preventing direct contaminant engagement with the spring while preserving automatic operation.
4Reliability
If particulates become pressed between the ball and seat, then they can create depressions in the surfaces forming permanent leak paths, but increasing spring force to prevent leakage worsens the contamination problem
Solution Approach 1:
The patent extracts the sealing function from the ball surface and relocates it to a dedicated seal member in a seal groove. This prevents particulates from being pressed into the ball surface to create permanent depressions, as the seal member provides a dedicated sealing interface that is not subject to repeated high-pressure contact with the ball.
Solution Approach 2:
The patent employs flexible elastomeric seals that can deform to maintain sealing contact without creating permanent surface depressions. Even if particulates are present, the flexible seal material can conform around them rather than being pressed into rigid surfaces, preventing permanent leak paths.
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 valve effectively prevents leaks and maintains sealing integrity even in the presence of contaminants, ensuring reliable operation under various pressure conditions, particularly beneficial for micro valves and applications where cleanliness is critical.
Implementation Method 1
an elastomeric biasing spring disposed in the seal piston bore and biasing the cam in the direction toward the sloped wall
Implementation Method 2
A valve construct useful for at least a check valve, pressure relief valve or pressure regulating valve... selectively open or close fluid communication between a fluid inlet and a fluid outlet in response to a fluid pressure differential
Data Source
AI summary
A valve configured to selectively communicate fluid pressure therethrough includes a valve body having an inlet, an inlet bore extending inwardly of the body from the inlet, a reduced diameter bore, a cam bore, and an outlet bore therein, the outlet bore in fluid communication with the cam bore, and the cam bore including a sloped wall therein extending inwardly on the cam bore in the direction away from the inlet bore, a first piston disposed in the a reduced diameter bore and including a piston passage therethrough fluidly communicating between the inlet bore and the cam bore, a cam disposed in the cam bore and having a self-energizing seal and a lower angled surface engagable against the sloped wall, the self-energizing seal disposed in a seal piston bore therein, and an outlet extending to the exterior of the valve body and opening into the lower angled surface.