Aerofoil Tip Section Rotary Hinge Mechanism
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Solution Overview
Problem
Current aircraft designs with larger wingspans face challenges in accessing restricted airport gates due to weight and inefficiency issues with existing folding wing mechanisms, and safety concerns arise from wing tip flutter and frequent clamp wear.
Innovation Solution
A rotary hinge unit with a compound angle and a clamp unit featuring a ramped slot and actuator ensure efficient wing tip rotation and secure locking, reducing wingspan and minimizing weight and wear, while maintaining aircraft safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If a piano-type hinge is used to fold the wing tip vertically, then the wingspan is reduced to access restricted airport gates, but the weight of the lifting means increases significantly
Solution Approach 1:
The invention uses a dynamically adjustable linkage mechanism that changes its configuration during the folding process. The linkage transitions from a fully extended position (providing maximum mechanical advantage) to a retracted position, allowing the same mechanism to provide high torque initially while requiring minimal torque at the end of the folding stroke. This dynamic adjustment eliminates the need for oversized lifting means throughout the entire range of motion.
Solution Approach 2:
The invention changes the mechanical parameters (torque requirements, linkage angles, moment arms) during the folding process. By varying these parameters dynamically, the system achieves high torque multiplication when needed (at the start of folding) and reduces torque requirements as folding progresses, thereby reducing the overall size and weight of the lifting mechanism required.
2Force
If a high-torque lifting means is used to lift the wing tip, then the initial lifting capability is sufficient, but the torque capability is wasted for all but the initial phase of the lift
Solution Approach 1:
The linkage mechanism dynamically adjusts its mechanical advantage ratio during the folding process. At the beginning of the stroke, the linkage is configured to provide maximum torque multiplication. As folding progresses, the linkage retracts and the torque requirement naturally decreases. This dynamic configuration ensures that the lifting means operates at or near its maximum capability throughout the entire range of motion, eliminating wasted capacity.
Solution Approach 2:
Instead of providing excessive torque capability throughout the entire folding process, the invention uses a linkage that provides exactly the right amount of torque at each stage. The mechanical advantage is partially applied when needed (at the start) and gradually reduced as the folding progresses, matching the actual torque requirements rather than providing constant excessive capability.
3Device complexity
If a simple shot-bolt clamp is used to lock the wing tip, then the structure is simple, but clearance is required which allows play and wing tip flutter
Solution Approach 1:
The invention extracts the clearance requirement from the locking mechanism by using a positive engagement system. Instead of relying on friction and clearance (as in shot-bolt clamps), the mechanism uses interlocking teeth or a cam-based positive lock that engages without requiring play. This eliminates the source of flutter while maintaining structural simplicity.
Solution Approach 2:
The mechanism incorporates a pre-loaded spring or cam that applies constant force to maintain tight engagement between the locking components. This beforehand cushioning ensures that no play or clearance develops during operation, preventing flutter before it can occur, while the overall structure remains simple.
4Ease of operation
If clearance is provided in the clamp to allow free sliding, then engagement and disengagement are easy, but play translates to large movement at the wing tip
Solution Approach 1:
The invention removes the clearance that causes excessive wing tip movement by using a positive engagement locking mechanism. The clamp uses interlocking features or a cam-based system that engages without requiring play, thereby eliminating the amplification effect while maintaining ease of operation through a simple actuation mechanism.
Solution Approach 2:
Instead of allowing movement in one dimension (clearance for sliding) and accepting the consequences in another dimension (wing tip play), the invention changes the locking approach to a different dimensional principle - using a positive engagement system that locks in the rotational dimension without requiring linear clearance, thereby preventing the amplification of small movements into large wing tip excursions.
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
The solution allows larger aircraft to access restricted gates with reduced weight and increased efficiency, minimizing wing tip flutter and extending clamp unit lifespan, thus enhancing practicality and safety.
Implementation Method 1
a fixed gear mounted concentrically on the hinge shaft, and a drive gear coupled to the tip section and configured to mesh with the fixed gear, wherein a rotation of the drive gear against the fixed gear causes the tip section to rotate about the hinge shaft
Implementation Method 2
the clamp unit comprising a ramped slot and a clamp head configured to move along the slot until a frictional engagement corresponding to a locked configuration of the clamp unit is reached
Data Source
AI summary
There is provided an aerofoil comprising an inboard section, a tip section moveable between a flying configuration and a parked configuration, a hinge shaft mounted at a compound angle in the inboard section, a fixed gear mounted concentrically on the hinge shaft and a drive gear coupled to the tip section and configured to mesh with the fixed gear, wherein a rotation of the drive gear against the fixed gear causes the tip section to rotate about the hinge shaft between the flying configuration and the parked configuration.