Aircraft Thrust Reverser Rack and Pinion Drive
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Solution Overview
Problem
Existing aircraft gas turbine thrust reverser designs with sliding elements suffer from high friction, leading to complex structures, increased weight, and high costs due to stability and jamming issues, requiring intricate manufacturing and redundant systems for reliable operation.
Innovation Solution
A rack and pinion drive system actuates petal cascade elements, ensuring synchronized movement and eliminating jamming risks, with toothed racks on each element connected to a central drive unit, allowing for reliable displacement of the engine cowling and thrust reverser operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If sliding elements with plain bearings are used for thrust reverser operation, then the structure can be simple, but friction increases causing high reaction forces and jamming risks
Solution Approach 1:
The patent replaces the sliding element mechanism with a rack and pinion drive system. The rack and pinion mechanism eliminates direct sliding contact between thrust reverser doors and engine cowling, substituting it with a gear-based actuation system that transmits force without friction-induced jamming. This mechanical substitution resolves the contradiction by maintaining structural simplicity while eliminating the reliability issues associated with sliding elements.
2Reliability
If redundant drive means and monitoring measures are added to prevent jamming, then operational safety improves, but device complexity and manufacturing costs increase
Solution Approach 1:
The patent extracts and eliminates the need for redundant drive means and monitoring measures by implementing a single, well-designed rack and pinion drive system. The rack and pinion mechanism inherently prevents jamming through its gear-based operation, removing the necessity for backup systems. This extraction of unnecessary components reduces device complexity while maintaining operational safety.
3Reliability
If small tolerances during manufacture are enforced to maintain functionality, then operational reliability improves, but manufacturing complexity and costs increase
Solution Approach 1:
The patent segments the thrust reverser system into modular components, particularly the petal-shaped cascade elements that can be manufactured separately and then assembled. This segmentation allows for standardized manufacturing processes with relaxed tolerances on individual components, while the overall assembly maintains functionality. The modular approach reduces manufacturing complexity compared to monolithic designs requiring tight tolerances throughout.
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 simplifies the structure, reduces weight and manufacturing complexity, and enhances operational safety by eliminating redundant systems and jamming, while ensuring reliable and efficient thrust reverser operation.
Implementation Method 1
a toothed rack is formed on one or both sides of each petal cascade element, which can be moved via a respective gear wheel that is coupled to a drive device
Implementation Method 2
each petal cascade element is connected via at least one coupling element to a rear region of the engine cowling for its displacement in the axial direction
Data Source
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AI summary
The present invention relates to an aircraft gas turbine comprising a thrust-reverser device that is arranged at the rear area of an engine cowling and that has multiple cascade elements which are distributed at the circumference and which divert a stream, characterized in that the cascade elements are mounted in a displaceable manner, in that on both sides of each cascade element at least one gear rack is formed that can be displaced via a respective cog wheel which is coupled to a driving device, and in that each cascade element is connected to a rear area of the engine cowling via a coupling element for the purpose of displacing the engine cowling in the axial direction.