Two-Ply Bellows Seal Joining to Prevent Ply Separation
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Solution Overview
Problem
Gas turbine engines face fluid leakage issues between rotor and stator stages, and existing bellows seals are prone to ply separation during operation, which can reduce their effectiveness and operational lifespan.
Innovation Solution
A metal gasket bellows seal with multiple coupling locations, using resistance, laser, or electron beam welding, and an adhesive with a melting temperature below the operating temperature, applied at specific positions to prevent ply separation and maintain seal integrity during transportation and assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bellows seals include multiple plies to reduce fluid leakage, then sealing performance is improved, but the likelihood of ply separation increases
Solution Approach 1:
The patent applies preliminary action by spot joining the first and second plies at multiple locations during manufacturing, before the seal is installed and subjected to operational stresses. This pre-joining prevents ply separation from occurring during service, addressing the contradiction by establishing structural integrity in advance.
Solution Approach 2:
The patent combines multiple joining methods - spot joining (welding or brazing) at multiple locations around the seal circumference, plus adhesive bonding at the slip joint. This merging of joining techniques creates redundant attachment points that prevent ply separation while maintaining the multi-plied sealing structure.
2Ease of manufacture
If adhesive is used to couple plies at the slip joint, then ease of assembly is improved, but the adhesive may melt at temperatures below operating temperature
Solution Approach 1:
The patent applies beforehand cushioning by selecting an adhesive specifically designed to melt at a controlled temperature below the operating temperature. This controlled melting acts as a safety mechanism - the adhesive holds the plies together during assembly and transportation, then melts during a green run or initial operation to allow the slip joint to function properly, preventing damage from thermal expansion constraints.
Solution Approach 2:
The patent exploits phase transitions by using an adhesive that transitions from solid to liquid at a specific temperature. During assembly and transportation, the adhesive is solid and provides bonding. During initial operation (green run), the temperature rises above the adhesive's melting point, causing it to transition to liquid and release the plies, allowing the slip joint to accommodate thermal expansion without damage.
3Productivity
If the seal is manufactured remotely from the assembly facility, then manufacturing efficiency is improved, but the risk of ply separation during transportation increases
Solution Approach 1:
The patent applies preliminary action by spot joining the plies at multiple locations during remote manufacturing, before transportation. This pre-joining ensures that the plies remain attached during the transportation process from the manufacturing facility to the assembly facility, preventing ply separation despite the extended handling and transport time enabled by remote manufacturing.
Solution Approach 2:
The patent combines multiple joining methods - spot joining at multiple locations around the seal circumference plus adhesive bonding at the slip joint. This merging of joining techniques creates redundant attachment points that prevent ply separation during transportation, enabling the seal to be manufactured remotely and then transported safely to the assembly facility.
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 solution effectively reduces ply separation and maintains seal integrity under high temperatures and mechanical stress, enhancing the performance and lifespan of gas turbine engines by minimizing fluid leakage and accommodating thermal expansion.
Implementation Method 1
an adhesive to couple the first ply and the second ply at the slip joint
Implementation Method 2
the adhesive may be configured to melt at a melting temperature that is less than an operating temperature of an environment of the metal gasket bellows seal
Implementation Method 3
the spot joining may include at least one of at least one of resistance welding, laser welding or electron beam welding
Implementation Method 4
the spot joining may include at least one of at least one of resistance welding, laser welding or electron beam welding
Implementation Method 5
the spot joining may include at least one of at least one of resistance welding, laser welding or electron beam welding
Data Source
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AI summary
A metal gasket bellows seal (300) includes a first ply (400) and a second ply (402) coupled to the first ply at a first location (428) via spot joining at one or more locations.