Blade Pocket Seal Alignment via Asymmetric Abutments
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Solution Overview
Problem
The misinstallation of feather seals in gas turbine engines due to asymmetric blade pocket cavities can lead to inefficiencies in sealing, as the seals may not properly contact the cavity surfaces, resulting in air leakage and reduced engine performance.
Innovation Solution
The design includes a blade with a platform portion featuring a cavity with an abutment at the trailing end, which ensures proper alignment and contact of the seal along its periphery, preventing misinstallation by mechanical interference, thus ensuring constant contact and minimizing air leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If feather seals are used in asymmetric blade pocket cavities, then sealing efficiency can be improved, but the risk of misinstallation increases due to asymmetric shape requirements
Solution Approach 1:
The invention introduces asymmetric abutments with different heights at the trailing edge of the blade platform, corresponding to the asymmetric feather seal design. The abutments create mechanical stops that guide the seal into the correct asymmetric position within the blade pocket cavity, ensuring proper installation while maintaining the asymmetric sealing configuration needed for high sealing efficiency
Solution Approach 2:
The abutments are pre-positioned on the blade platform during manufacturing, establishing predetermined stopping positions for the feather seal legs. This preliminary positioning action ensures that during assembly, the seal automatically aligns with the correct asymmetric orientation without requiring additional installation steps or worker judgment
2Reliability
If seals are designed with asymmetric shapes to match blade pocket cavities, then sealing contact along the gap is improved, but manufacturing complexity increases
Solution Approach 1:
The feather seal is designed with asymmetric leg lengths to match the asymmetric geometry of the blade pocket cavity and abutments. This asymmetric configuration enables the seal to contact the cavity surfaces along the entire gap length, ensuring reliable sealing while the standardized asymmetric design facilitates consistent manufacturing
3Ease of operation
If abutments are added to prevent misinstallation, then installation correctness is improved, but device complexity increases
Solution Approach 1:
Rather than making the entire blade structure complex, the invention adds localized abutment features only at the trailing edge of the platform where they are needed to guide the seal. This localized approach provides the necessary installation guidance while minimizing the overall structural complexity of the blade
Data Source
AI summary
An assembly comprising a blade including a blade portion, a root portion and a platform portion between the blade portion and the root portion, the platform portion defining at least one cavity opened laterally. An abutment projects from a wall portion of the cavity at a trailing end of the blade. A seal is received in the cavity and positioned along a periphery of the cavity, the seal having a trailing edge abutting against the abutment.