Thrust Reverser Actuation Mechanism for Aero Engine Nozzle Control
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Solution Overview
Problem
Existing thrust reversal and nozzle section variation devices in turbojet engines face issues with complex actuation kinematics, reliability, maintenance difficulties, aerodynamic losses, and structural dependencies, leading to unwanted deviations and increased complexity.
Innovation Solution
A thrust reverser device with a movable cowl and rotatable panels, actuated by a drive rod system that maintains rectilinear movement parallel to the nacelle axis, eliminating guide rods through the cold flow stream and ensuring aerodynamic continuity, with actuating means comprising concentric bodies and distinct linear actuators for controlled differential movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If guide rods are used to pivot panels from one position to another, then panel positioning is achieved, but aerodynamic disturbances and drag are generated in the cold flow stream
Solution Approach 1:
The patent removes the guide rods that crossed the cold flow stream, extracting the source of aerodynamic disturbances. The panel pivoting is achieved through the actuator's rotational capability without requiring external guide rods, thereby eliminating the harmful aerodynamic effects while maintaining panel positioning functionality.
2Adaptability or versatility
If the actuator is connected to the movable cowl and panel upstream end, then simultaneous actuation is achieved, but the actuator displacement becomes non-linear during panel pivoting
Solution Approach 1:
The patent employs a dynamically adjustable actuator mechanism that can adapt its movement pattern. The actuator is capable of performing both translational movement (for simultaneous actuation of cowl and panel) and rotational movement (for panel pivoting). This dynamic capability allows the system to maintain simple rectilinear actuator displacement while achieving complex coordinated motion through the actuator's dual movement modes.
3Adaptability or versatility
If the movable cowl is displaced significantly during nozzle section variation, then nozzle section adjustment is achieved, but structural overlaps increase and aerodynamic line continuity is broken
Solution Approach 1:
The patent adds a rotational dimension to the panel actuation mechanism. Instead of relying solely on large translational displacements of the movable cowl, the panels can pivot rotationally about an axis. This dimensional change allows for effective nozzle section adjustment with minimal cowl displacement, preserving aerodynamic line continuity and avoiding structural overlaps.
4Ease of operation
If dedicated actuation systems are used for the variable nozzle and movable cowl, then desired kinematics are achieved, but system reliability decreases and maintenance becomes difficult
Solution Approach 1:
The patent employs a single multi-functional actuator that can perform multiple operations: translating the movable cowl, pivoting the panels, and coordinating their simultaneous movement. This universal actuator replaces multiple dedicated actuation systems, simplifying the overall structure, improving reliability by reducing the number of independent systems, and facilitating maintenance through a more straightforward mechanical design.
Data Source
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AI summary
The invention relates to a thrust reversing device (20) that includes at least one mobile cowling (30) mounted in translation in a direction substantially parallel to a longitudinal axis of a nacelle, capable of moving alternatively from a closing position on which it enables the aerodynamic continuity of the nacelle into an opening position in which it opens a passage in the nacelle for the bypassed flow, wherein said mobile cowling (30) also includes as an extension at least one variable nozzle section (40) including at least one panel (41) mounted so as to be capable of rotation, the panel (41) being adapted for pivoting towards at least one position entailing a variation in the nozzle section (40) on the one hand, and pivoting towards a position in which it blocks a cold flow jet (13) formed between a fixed structure of a turbojet fairing (12 and the nacelle on the other hand, wherein the mobile cowling (30) and the panel (41) are associated with actuation means (50) capable of activating the respective translation and rotation movements thereof, characterized in that said actuation means (50) are connected to an upstream end of the panel (41) by a driving connection rod (61) capable of moving about anchoring points respectively on the corresponding panel (41) and the associated actuation means (50).