Aircraft Wing Rib-Stringer Seal for Tolerance-Absorbing Aperture Sealing
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Solution Overview
Problem
The existing methods for sealing mouseholes in aircraft wing structures are time-consuming, create access restrictions, and are not suitable for composite materials, as they require precise fitting and drilling after assembly, which is unsafe and increases weight.
Innovation Solution
A self-adjusting seal system comprising a first seal part engageable with the rib and a second seal part engageable with the stringer, featuring sliding adjusters and camming means to absorb dimensional tolerances, allowing for pre-assembly machining and assembly without post-assembly access to the wing box.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If seal plates are individually formed and fitted after wing assembly, then sealing accuracy is improved, but manufacturing time and complexity increase significantly
Solution Approach 1:
The seal plate is pre-formed with a recessed portion that anticipates the stringer's position within tolerance ranges. This preliminary configuration allows the seal to self-adjust during assembly without requiring post-assembly fitting or drilling operations, thereby maintaining sealing accuracy while dramatically reducing manufacturing time and complexity.
Solution Approach 2:
The seal plate design incorporates a recessed portion with specific dimensional parameters that accommodate stringer position variations. By carefully designing the recess depth and width parameters, the seal can absorb tolerance variations in stringer positioning while maintaining effective sealing, eliminating the need for custom-fitted seal plates for each mousehole.
2Manufacturing precision
If drilling and fitting operations are performed after wing assembly, then sealing precision is improved, but access restrictions and safety issues worsen
Solution Approach 1:
All necessary drilling and machining operations are completed on the seal plate before it is installed on the wing. The recessed portion is pre-formed to accommodate the stringer, allowing precise machining with full tool access. Once installed, the seal requires no further adjustment or drilling, eliminating safety concerns associated with working inside the assembled wing box.
3Reliability
If traditional seal plates are used for composite wing boxes, then sealing is achieved, but weight and structural integrity are compromised
Solution Approach 1:
The seal plate is segmented into a main body and a recessed portion that interfaces with the stringer. This segmentation allows the seal to be installed on the rib structure before the wing box is closed, avoiding the need to create access holes in the composite covers. The recessed portion fits around the stringer to provide sealing without requiring additional structural modifications that would increase weight.
4Manufacturing precision
If seal plates are custom-fitted to each mousehole, then sealing accuracy is improved, but device complexity and inspection requirements increase
Solution Approach 1:
The seal plate design with the recessed portion is a universal solution that can be used for all mouseholes in the wing structure. The recess is designed to accommodate stringers within the specified tolerance range, making the same seal plate design applicable across multiple locations without requiring custom fabrication for each mousehole, thereby reducing device complexity and inspection requirements.
Data Source
AI summary
A seal for sealing an aircraft fuel tank, an aircraft wing rib and stringer sealing assembly, an aircraft wing fuel tank, an aircraft structural wing box, an aircraft wing, and a method of sealing an aperture are disclosed. The seal is for sealing a wing rib to a stringer passing through an aperture in the rib at a variable position in the aperture. The seal includes self-adjustment means to absorb any tolerance when forming the seal, upon the stringer being assembled into the aperture in the rib.