Finger Seal Retention System for Gas Turbine Engines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing seal systems for gas turbine engines face challenges in maintaining effective sealing while allowing for easy removal and replacement of finger seals, which are prone to damage due to thermal expansion mismatches and require fasteners that compromise the structural integrity of the fairing.
Innovation Solution
A finger seal retention system where the finger seal is removably attached using a tab that is bent at an angle and inserted into a channel, allowing for easy detachment and reattachment without fasteners, and is permanently secured to the fairing using welding, brazing, or bonding, with a cooling air gap for insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If finger seals are attached using bolts and nuts or rivets and doubler plates, then the finger seal is securely fixed to the fairing, but the structural integrity of the fairing is compromised and the attachment process becomes complex
Solution Approach 1:
The attachment system is segmented into three distinct components: the fairing, the finger seal, and the retention unit. This segmentation allows each component to be optimized independently and simplifies the overall attachment process by eliminating the need for complex fastening mechanisms.
Solution Approach 2:
The tab of the finger seal is inserted into and nested within the retention unit, creating a nested configuration. This nested arrangement provides secure fixation while maintaining simplicity, as the tab is retained by the retention unit without requiring additional fasteners.
2Reliability
If finger seals are permanently attached to the fairing, then the sealing is reliable, but the maintenance and replacement of finger seals becomes difficult
Solution Approach 1:
The attachment system transitions from a static permanent attachment to a dynamic removable attachment. The tab can be inserted into the retention unit for secure operation and removed when maintenance is required, providing both reliability during operation and ease of repair during maintenance.
Solution Approach 2:
The retention unit acts as an intermediary component between the finger seal and the fairing. This intermediary allows the finger seal to be securely attached during operation while enabling easy removal and replacement when needed, without requiring permanent attachment methods.
3Reliability
If the tab completely occupies the opening between the fairing and the finger seal retention unit, then the sealing is improved, but the cooling air path is blocked
Solution Approach 1:
The tab is designed with local quality variations: it has a sealing portion that contacts the fairing to provide effective sealing, and a non-sealing portion that leaves space for cooling air flow. This localized differentiation allows the tab to perform both sealing and cooling functions simultaneously.
Solution Approach 2:
The tab is designed as a thin, flexible component that can conform to the sealing surface while maintaining gaps for cooling air flow. The flexibility allows it to provide effective sealing contact while its thin profile and strategic positioning preserve the cooling air path.
4Ease of operation
If the tab is bent at an angle before insertion, then the installation is easier and the seal is more effective, but the manufacturing process becomes more complex
Solution Approach 1:
The tab is pre-bent at an angle during manufacturing to facilitate easier insertion and achieve better sealing contact. This preliminary action of bending the tab before installation simplifies the installation process and improves sealing effectiveness, while the bending operation can be integrated into the manufacturing process.
Solution Approach 2:
The tab's geometric parameters, specifically its angle, are changed during manufacturing to optimize both installation ease and sealing effectiveness. By controlling the bending angle as a manufacturing parameter, the process achieves improved operational characteristics while maintaining manufacturing feasibility.
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 solution ensures reliable sealing, reduces thermal stress on the finger seal, and allows for easier maintenance and replacement without compromising the structural integrity of the fairing, while also providing insulation to mitigate heat transfer.
Implementation Method 1
a cooling air gap for insulation
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A seal system for a gas turbine engine (10) is disclosed. The seal system includes a fairing (46). The seal system also includes a finger seal retention unit (104) attached to the fairing (46), the finger seal retention unit (104) comprising a channel (502) defining an opening between the fairing (46) and the finger seal retention unit (104). The seal system also includes a finger seal (102) comprising a tab (404) corresponding to the channel (502) of the finger seal retention unit (104), the finger seal (102) configured to be removably attached to the finger seal retention unit (104) by inserting the tab (404) into the channel (502).