Dual Vacuum Seal Structure for Cleaning-Gas-Resistant Chambers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In vacuum systems, there is a conflict between achieving low leakage and permeation for maintaining a high vacuum while ensuring that seals are resistant to cleaning gases, as exposure to these gases can cause degradation and leaks.
Innovation Solution
A vacuum system design using distinct materials for outer and inner seals, where the outer seal provides tighter vacuum sealing and is less resistant to cleaning gases, and the inner seal is more resistant, with a gap between them evacuated by a vacuum pump to reduce pressure differential.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If identical material O-rings are used for both inner and outer seals, then the sealing structure is simple and easy to manufacture, but the inner seal degrades when exposed to cleaning gases causing leaks and particle emission
Solution Approach 1:
The patent applies local quality by using different materials for the inner and outer seals based on their specific functional requirements. The inner seal uses material resistant to cleaning gases (e.g., perfluoroelastomer), while the outer seal uses material optimized for vacuum sealing (e.g., fluoroelastomer). This resolves the contradiction by tailoring material properties to local needs rather than using a uniform material throughout.
Solution Approach 2:
The patent employs composite materials by combining different elastomeric materials in the dual seal configuration. Each seal is made from a distinct material selected for its specific properties - the inner seal from gas-resistant material and the outer seal from vacuum-sealing-optimized material. This composite approach allows both seals to perform their respective functions optimally without compromising either reliability or manufacturability.
2Reliability
If the inner seal is made more resistant to cleaning gases, then seal degradation and particle emission are reduced, but vacuum sealing tightness may be compromised
Solution Approach 1:
The patent resolves this contradiction by assigning different material qualities to different locations. The inner seal is specifically engineered with gas-resistant material properties, while the outer seal is engineered with vacuum-sealing-optimized material properties. This local differentiation ensures that each seal performs its primary function optimally without compromising the other.
Solution Approach 2:
The patent segments the sealing function into two distinct seals with different material compositions. The inner seal handles gas resistance while the outer seal handles vacuum sealing tightness. This segmentation allows independent optimization of each seal's material properties according to its specific functional requirements, resolving the contradiction between gas resistance and sealing tightness.
3Device complexity
If a single seal is used between the wall and flange, then the sealing structure is simple, but it cannot simultaneously provide tight vacuum sealing and resistance to cleaning gases
Solution Approach 1:
The patent segments the single seal function into two separate seals with distinct material properties. The inner seal is dedicated to resisting cleaning gases, while the outer seal is dedicated to providing tight vacuum sealing. This segmentation resolves the contradiction by allowing each seal to be optimized for its specific function, achieving both gas resistance and sealing tightness simultaneously.
Solution Approach 2:
The patent uses composite materials in the form of two different elastomeric materials arranged in a dual seal configuration. Each material is selected for its specific properties - one for gas resistance and one for vacuum sealing optimization. This composite material approach enables the system to achieve both reliability requirements that a single material could not satisfy alone.
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 enhances vacuum sealing while minimizing seal degradation and particle emission during cleaning, maintaining a high vacuum and reducing contamination within the chamber.
Implementation Method 1
The outer seal is separated from the inner seal by a gap. The outer seal is capable of providing tighter vacuum sealing between the wall and the flange than the inner seal. The vacuum system also includes a path to couple the gap to a first vacuum pump, to evacuate the gap.
Data Source
AI summary
A vacuum system includes a wall of a vacuum chamber, a flange of the vacuum chamber, an outer seal disposed between the wall and the flange, and an inner seal disposed between the wall and the flange. The outer seal includes a first material; the inner seal includes a second material distinct from the first material. The inner seal is closer to the interior of the vacuum chamber than the outer seal and is separated from the outer seal by a gap. The outer seal may be capable of providing tighter vacuum sealing between the wall and the flange than the inner seal. The inner seal may be more resistant than the outer seal to a gas to be used to clean the interior of the vacuum chamber. The vacuum system also includes a path to couple the gap to a first vacuum pump, to evacuate the gap.