Aircraft Wing Pylon Fastening via Eccentric Rings
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Solution Overview
Problem
Conventional aircraft assemblies require spigots to absorb shear forces in the XY plane, which complicates the assembly process and increases the need for counter-drilling, making it inefficient and prone to pairing tasks during final assembly.
Innovation Solution
The proposed assembly uses a mast with an upper spar and side scoops, along with a wing having longitudinal spars and fittings, employing eccentric rings and a rotation stop system to absorb shear forces without spigots, utilizing screws with smooth and threaded zones, and nuts to securely fasten the components, reducing tolerance gaps and eliminating the need for spigots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If spigots are installed to absorb shear forces in the XY plane, then the structural stability is improved, but the assembly complexity and manufacturing difficulty increase due to the need for counter-drilling and pairing tasks
Solution Approach 1:
The invention extracts and eliminates the spigots from the assembly system by transferring the shear force absorption function to the tension bolts. The tension bolts are designed with sufficient surface area and positioning to directly absorb shear forces in the XY plane, making the separate spigot components unnecessary and simplifying the overall assembly structure
Solution Approach 2:
The tension bolts are given multiple functions: they not only absorb vertical forces (Z direction) but also absorb shear forces in the XY plane. This multi-functional design eliminates the need for separate spigot components, reducing assembly complexity while maintaining structural stability
2Reliability
If spigots are used to ensure force absorption, then the reliability of force transmission is improved, but the manufacturing precision requirements increase due to tolerance gaps and alignment needs
Solution Approach 1:
The invention merges the force absorption functions of both spigots and tension bolts into a single integrated system. The tension bolts are positioned and dimensioned to simultaneously handle vertical and shear forces, eliminating the need for separate spigot components and their associated alignment requirements
Solution Approach 2:
The invention changes the critical parameters by increasing the surface area of the tension bolts and optimizing their positioning. This allows the bolts to directly absorb shear forces without requiring the tight tolerance gaps and precise alignment that would be necessary if separate spigot components were used
3Ease of operation
If tension bolts with large clearance are used to accommodate tolerance gaps, then the ease of assembly is improved, but the force absorption capacity in the XY plane is reduced
Solution Approach 1:
The invention applies preliminary action by pre-positioning the tension bolts with optimized surface area and positioning before final assembly. This preliminary design ensures that the bolts are capable of absorbing shear forces from the outset, eliminating the need for large clearance accommodations and subsequent counter-drilling operations
Data Source
AI summary
The invention relates to an assembly (200) comprising a mast (106) with an upper spar (202) and four side blades (212a), a wing with a skin (210), longitudinal spars (206a-b) and fittings (208), and for each side blade (212a), two fastening assemblies (250), wherein the skin (210) and the fitting (208) each have a first bore (251) and wherein the upper spar (202) and the side blade (212a) each have a second bore (253), wherein each fastening assembly (250) has a screw (254) passing through the first and second bores (251, 253), a nut (255), two eccentric rings (256, 258), threaded one on the other and on the screw (254), and a rotation stop system (260) for the eccentric rings (256, 258).The assembly makes it possible to do without the use of spigots while ensuring the absorption of shear forces contained in the XY plane by the bolts due to the reduced tolerances between the different bores (251,253), the external and internal surfaces of the eccentric rings (256, 258) and the smooth areas of the screws (254).