Evacuation Valve O-Ring Seal Holder Design
Solution Overview
Problem
Existing metering devices for liquid lubricants face issues with inconsistent surface finishes and labor-intensive assembly processes in evacuation valves, leading to poor sealing and potential leaks, especially when using sheet stock or molded seals.
Innovation Solution
The use of an O-ring seated within an annular groove in a seal holder, where the O-ring is held in place by a spring and forms a critical sealing surface without the need for adhesives or specialized molding, allowing for consistent and uniform sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If sheet stock material is used for the seal, then the seal can be cut and affixed to the seal holder, but the surface finish is inconsistent leading to poor sealing
Solution Approach 1:
The patent replaces the reusable sheet stock seal with a disposable molded seal made from elastomeric material. The molded seal is formed directly in the mold cavity, eliminating the need for cutting and adhesive application. This disposable approach ensures consistent surface finish and geometry without the variability inherent in sheet stock processing.
Solution Approach 2:
The patent changes the material state from sheet stock (requiring cutting and adhesive) to liquid elastomeric material that is molded into the final seal shape. This parameter change from solid sheet to liquid moldable material enables consistent surface finish and eliminates the need for secondary operations like cutting and gluing.
2Ease of manufacture
If sheet stock seal is cut and glued to seal holder, then the seal can be assembled, but the process is labor intensive requiring multiple inspections
Solution Approach 1:
The patent merges the seal and seal holder into a single integrated component by molding the seal directly onto the seal holder within the same mold cavity. This eliminates the separate operations of cutting the seal, applying adhesive, and assembling the components, thereby dramatically improving productivity and reducing inspection requirements.
Solution Approach 2:
The seal is pre-formed in the correct position and geometry during the molding process itself, rather than being cut and attached afterward. This preliminary formation of the seal in its final position eliminates the need for subsequent assembly operations and inspections.
3Ease of manufacture
If molded seal material is injected into the mold, then the seal is formed within the cavity, but the rubber seal material can pull out resulting in non-flat seal
Solution Approach 1:
The patent uses an O-ring with a curved cross-sectional shape instead of a flat molded seal. The curved geometry of the O-ring provides inherent structural stability that prevents it from deforming or pulling out during removal from the mold, ensuring consistent sealing surface flatness without requiring additional retention features.
4Stability of the object's composition
If hex broach is formed in mold cavity to prevent rotation, then seal rotation is prevented, but flash material forms on top surface that must be removed
Solution Approach 1:
The patent extracts the hex broach feature from the mold design, eliminating the source of flash material. Instead of using a hex broach that creates flash, the O-ring's inherent curved geometry and friction fit in the annular groove provide sufficient anti-rotation capability without generating excess flash that would require cleanup.
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
This design provides a more economical, reliable, and longer-lasting evacuation valve with improved sealing performance and reduced assembly complexity, ensuring accurate metering of liquid media even in small quantities.
Implementation Method 1
A spring holds the O-ring seal in place
Data Source
AI summary
An evacuation valve for a metering device or pump for a liquid medium is disclosed. The valve includes a seal holder having an annular groove formed therein and an O-ring seal. The O-ring seal is positioned within the annular groove and provides an evacuation valve seal surface.