Turbofan Thrust Reverser Single Actuator Control
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Solution Overview
Problem
The existing actuation systems for thrust reversers in aircraft nacelles require additional mass to transmit axial thrusts to the secondary nozzle, leading to complex control mechanisms with multiple locks, which increases complexity and weight.
Innovation Solution
A thrust reverser design where cylinders are directly connected to the secondary nozzle, and locks are linked to the movable cowls, allowing for two-position control that alternates between blocking the front structure and the secondary nozzle, eliminating the need for additional mass transmission and simplifying the control system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If cylinders are used to transmit axial thrusts to the secondary nozzle through the movable cowls, then the secondary nozzle can be controlled, but additional mass is required to transmit the stresses
Solution Approach 1:
The control system is segmented into two independent locks: a fixed lock for linking the front structure to the cowls, and a movable lock for linking the cowls to the secondary nozzle. This segmentation allows the cylinders to control only the secondary nozzle when the movable lock is engaged, without requiring the nozzle to transmit the full axial thrust stresses, thereby reducing the required mass of the secondary nozzle.
2Adaptability or versatility
If two independent locks are used to control the movable cowls and secondary nozzle, then the control positions are achieved, but the control mechanism becomes complex
Solution Approach 1:
The fixed lock and movable lock are merged into a single integrated locking mechanism that provides two distinct locking positions. The fixed lock links the front structure to the cowls, while the movable lock links the cowls to the secondary nozzle. By combining these two locking functions into one mechanism, the system achieves multiple control positions without proportionally increasing complexity.
3Force
If the cylinders pass through the entire structure of the movable cowls to reach the secondary nozzle, then the axial thrust can be applied, but additional mass is required in the cowls to transmit the stresses
Solution Approach 1:
The stress transmission function is extracted from the movable cowls and assigned to the dedicated locking mechanism. The cylinders apply axial thrust to the secondary nozzle through the movable lock, which is specifically designed to handle these forces. The movable cowls are thus relieved of the burden of transmitting these stresses, allowing them to be constructed with less mass.
Data Source
Figure 1a~1c
Figure 2a~2c
Figure 2d~2e
AI summary
The invention relates to a thrust reverser of a turbofan pod, comprising movable cowlings (4) that retract relative to stationary front structure (2) to reveal stationary or movable thrust reverser cascades, as well as a secondary variable nozzle section (8) connected to the movable cowlings by guiding means enabling movement controlled by actuators (10) engaged with the front structure to apply an axial thrust. The invention is characterized in that the actuators (10) are directly connected to the secondary nozzle (8), and in that the thrust reverser comprises latches (14) connected to the movable cowlings (4), comprising two positions providing, alternately, latching onto the front structure (2) or latching onto the control (10) of the secondary nozzle (8).