Wing Tip Device Sealing via Non-Sliding Cut Line Geometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing aircraft wing tip devices face challenges in sealing between the fixed wing and the wing tip device, particularly due to relative sliding motion, which leads to wear and damage, necessitating frequent inspection and replacement.
Innovation Solution
The implementation of an interfacing cut line that separates the outer surfaces of the fixed wing and the wing tip device, comprising a first length offset from the primary cut plane, a second length within a plane containing the axis of rotation, and a transition section, allowing for non-sliding compression seals and reducing sliding contact, thereby enhancing sealing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sliding seal is employed at the interface between the fixed wing and wing tip device, then sealing can be provided during rotation, but the seal is subjected to large amounts of wear and damage requiring frequent inspection and replacement
Solution Approach 1:
Instead of using a sliding seal that accommodates relative motion through sliding contact, the invention inverts the approach by designing a non-sliding seal where the sealing surfaces separate during rotation. The seal is applied to surfaces that move apart rather than slide against each other, eliminating wear and extending service life while maintaining sealing effectiveness.
Solution Approach 2:
The interface between the fixed wing and wing tip device is segmented into multiple surfaces: a first surface that remains stationary for seal application, and a second surface that rotates and separates from the first surface. This segmentation allows the seal to remain on the stationary surface while the moving surface separates during rotation, avoiding sliding contact and wear.
2Adaptability or versatility
If the wing tip device rotates about an axis normal to the primary cut plane, then the span can be reduced in ground configuration, but relative sliding motion occurs at the interface requiring sliding seals that wear rapidly
Solution Approach 1:
The invention inverts the sealing approach by designing surfaces that separate during rotation rather than slide. The first surface is formed by a cut offset from the primary cut plane, and the second surface is formed by a cut through the outer surface, creating a geometry where rotation causes separation rather than sliding contact at the sealing interface.
Solution Approach 2:
Different regions of the interface have different functional qualities: the first surface provides a stationary sealing surface with specific geometric features for seal engagement, while the second surface is designed to rotate and separate from the first surface. This local differentiation of surface properties and functions eliminates sliding wear while maintaining the rotational span adjustment capability.
Data Source
AI summary
An aircraft (1002) including a wing (1001), having a fixed wing (1005) with a wing tip device (1003) moveably mounted at the outer end thereof. The wing tip device (1003) is moveable between: a flight configuration; and a ground configuration. The wing tip device (1003) and the fixed wing (1005) are separated along an oblique primary cut plane (1013). The wing tip device (1003) and the fixed wing (1005) meet along an interfacing cut line (1035). The interfacing cut line (1035) includes a first length (1037) offset from the primary cut plane (1013) in a first direction; a second length (1041) that extends within a plane (P) containing the axis of rotation (1011), or a plane parallel thereto; and a transition section (1039) over which the interfacing cut line (1035) transitions from the first length to the second length. The second length may extend around the upper surface, around the leading edge and onto the lower surface.