Nested Rack and Pinion Actuation for Wing Spar Integrity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional actuation systems for aerodynamic surfaces, such as leading edge slats on aircraft, require penetrations through the wing spar to extend and retract, which compromises fuel storage, structural integrity, and manufacturing complexity due to limited space and the need for additional seals and reinforcement.
Innovation Solution
An aerodynamic surface actuation system utilizing a rack and pinion mechanism with nested outer tracks and rollers that fit entirely within the wing, allowing full extension and retraction without penetrating the wing spar, using a carrier connected to a slat rib with rollers moving within inner channels and outer tracks that interface with fixed rollers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If single body tracks are used to extend and retract aerodynamic surfaces, then the surfaces can be actuated, but the track length required is greater than the space available inside the leading edge
Solution Approach 1:
The patent employs nested tracks where an inner track is positioned within an outer track. The inner track carries the aerodynamic surface and interfaces with rollers on the outer track, while the outer track interfaces with fixed rollers in the wing structure. This nesting arrangement allows the combined track system to achieve the necessary actuation length while fitting within the constrained space of the leading edge, eliminating the need for penetrations through the wing spar.
2Ease of operation
If penetrations are made in the wing spar to accommodate tracks, then the tracks can extend beyond the leading edge, but the structural strength of the wing spar is reduced
Solution Approach 1:
The nested track configuration allows both inner and outer tracks to be contained within the leading edge volume, eliminating the need for any penetrations through the wing spar. The outer track serves as a structural carrier that interfaces with fixed rollers mounted on the wing spar, providing track extension capability while maintaining spar integrity.
Solution Approach 2:
The patent transitions from a single linear track extending through the spar to a two-dimensional nested arrangement where tracks operate within the volume of the leading edge. This dimensional change allows the system to achieve the same functional extension without compromising the spar structure.
3Ease of operation
If penetrations are made in the wing spar, then tracks can pass through, but additional seals and structural reinforcement are required which increase weight and manufacturing complexity
Solution Approach 1:
The nested track system eliminates penetrations entirely, removing the need for slat cans, seals, and structural reinforcement. The outer track acts as a protective structure that contains the inner track system, allowing both to fit within the leading edge without requiring any openings in the wing spar.
Solution Approach 2:
The invention extracts and eliminates the problematic penetration components (slat cans, seals, reinforcement structures) by redesigning the track system to operate entirely within the available volume of the leading edge using nested tracks.
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
Enables full articulation of aerodynamic surfaces within constrained spaces without compromising structural integrity or fuel storage, reducing weight and manufacturing complexity, while maintaining the ability to achieve higher angles of attack for increased lift during take-off and landing.
Implementation Method 1
An aerodynamic surface actuation system utilizing a rack and pinion mechanism with nested outer tracks and rollers
Implementation Method 2
nested outer tracks and rollers that fit entirely within the wing, allowing full extension and retraction
Data Source
AI summary
Certain aspects of the present disclosure provide techniques for an aerodynamic surface actuation system, including: a plurality of outer tracks, wherein each outer track of the plurality of outer tracks include: an inner roller channel; and an outer roller channel positioned above the inner roller channel; an aerodynamic surface connected to a carrier, wherein the carrier includes: a plurality of rollers configured to move within inner roller channels of the plurality of outer tracks; and a carrier rack; a plurality of fixed rollers mounted to a plurality of longitudinal structural elements in an aerodynamic structure, wherein the plurality of fixed rollers are disposed within outer roller channels of the plurality of outer tracks; and a plurality of fixed racks, wherein each fixed rack of the plurality of fixed racks is mounted to a longitudinal structural element of the plurality of longitudinal structural elements.