Fuel Cell Gasket Sealing Structure for Offset Tolerance
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Solution Overview
Problem
The sealing performance of fuel cells is unstable due to displacement in surface pressure caused by assembly precision offsets, leading to fluctuations in power generation performance, as the existing gasket structures either fail to maintain desired seal properties or require wider gaskets to compensate for offset issues.
Innovation Solution
A sealing structure featuring a first gasket with a bank-like main lip and a second gasket with a flat seal portion and a bulging sub lip, where the main lip's width is wider than the assumed maximum offset and narrower than the flat seal portion, ensuring stable contact surface pressure and pinching of the membrane-electrode assembly even with offsets, without enlarging the gasket width.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a seal protrusion is used to concentrate surface pressure for desired sealing performance, then sealing performance is improved, but sealing performance becomes unstable due to displacement of surface pressure maximum portion caused by assembly precision offsets
Solution Approach 1:
The gasket is designed with a seal protrusion that concentrates surface pressure at a specific location (the tip of the protrusion) to ensure effective sealing. This local concentration of pressure creates a focused sealing action that compensates for assembly offsets, as the protrusion can shift slightly while maintaining contact with the sealing surface.
Solution Approach 2:
The gasket structure is designed in advance with a seal protrusion that anticipates possible assembly offsets. The protrusion is positioned and dimensioned to ensure that even if assembly precision varies within expected tolerances, the surface pressure maximum will still fall within the sealing region, pre-compensating for potential misalignments.
2Manufacturing precision
If a flat seal portion is used to prevent offset issues, then assembly precision tolerance is improved, but surface pressure is dispersed and desired seal property cannot be obtained
Solution Approach 1:
Instead of using a uniformly flat seal portion that disperses pressure, the invention employs a seal protrusion that creates a localized high-pressure region. This concentrated pressure application ensures effective sealing even when assembly offsets occur, as the protrusion maintains contact force at the critical sealing interface.
Solution Approach 2:
The seal protrusion design allows for dynamic adaptation to assembly offsets. The elastic gasket material enables the protrusion to shift position and maintain contact with the sealing surface, dynamically adjusting to accommodate variations in assembly precision while preserving sealing effectiveness.
3Reliability
If gasket width is increased to compensate for offset issues, then sealing performance stability is improved, but device complexity and size increase
Solution Approach 1:
The seal protrusion concentrates the sealing function into a specific localized region, allowing the gasket to maintain a compact overall width. The protrusion geometry ensures that sealing pressure is applied precisely where needed, eliminating the need to widen the entire gasket to achieve stable sealing performance across assembly offsets.
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 configuration maintains a stable contact surface pressure and sealing performance, preventing power generation fluctuations and bending moments on the membrane-electrode assembly, while avoiding the need for wider gaskets, thus stabilizing power generation and sealing efficiency.
Implementation Method 1
a first gasket (30) which is integrally provided in a separator (20A) arranged in one side in a thickness direction of the membrane-electrode assembly (10) and is made of a rubber-like elastic material
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
Disclosed is a sealing structure of a fuel cell, including a film-electrode composite (10) interposed between a first gasket (30) integrated with a separator (20A) and a second gasket (40), capable of ensuring stable sealing performance and stabilizing power generation performance in a power generation range even when an offset exists between the gaskets (30, 40) at either side of the film-electrode composite (10) due to poor assembling accuracy. To this end, the first gasket (30) has a bank-shaped main lip (32) of which top portion (32a) is brought into close contact with the film-electrode composite (10). The second gasket (40) has a flat sealing portion (42) and a sub lip (43) protruding from this flat sealing portion (42) at a position opposing the main lip (32), and the flat sealing portion and the sub lip are brought into close contact with the film-electrode composite (10). The width (w1) of the top portion (32a) of the main lip (32) is larger than the estimated maximum offset, is smaller than the width (w2) of the flat sealing portion (42), and is larger than the width (w3) of the sub lip (43).