Thrust Reverser Locking Assembly Inhibits Deflection
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Solution Overview
Problem
Conventional thrust reverser cowlings are prone to significant deflection under high-thrust engine loads, which can damage components and is not mitigated by increasing the thickness of inner walls due to space constraints, necessitating a solution to inhibit deflection.
Innovation Solution
The implementation of a locking assembly that includes a movable locking member coupled to a blocker door and drag link, which inhibits deflection of the nozzle inner wall when the blocker door is deployed and allows deflection when stowed, ensuring the inner V-groove and V-blade remain coupled and preventing load path alterations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the thickness of the inner walls is increased to prevent deflection, then the structural strength is improved, but the space constraints are violated
Solution Approach 1:
The inner wall structure is segmented into multiple components: the nozzle inner wall, the V-blade, the V-groove, and the locking member. This segmentation allows each component to be optimized independently for strength while maintaining overall compactness, resolving the contradiction between structural strength and space constraints.
Solution Approach 2:
The locking member is designed to be movable between locked and unlocked positions, allowing the structure to dynamically adjust its rigidity. During high-load operations, the locking member engages to prevent deflection, while during maintenance, it releases to allow access, thus providing strength when needed without permanently occupying additional space.
2Reliability
If the inner walls are made stiffer to inhibit deflection, then the reliability is improved, but the ease of maintenance is worsened
Solution Approach 1:
The locking member provides a dynamic solution where the structure transitions between rigid (locked) and flexible (unlocked) states. During operation, the locking member engages to prevent deflection and ensure reliability. During maintenance, the locking member is released to allow the V-blade and V-groove to be accessed and serviced, thus maintaining ease of maintenance.
Solution Approach 2:
The locking mechanism is extracted as a separate, removable component that can be independently accessed and serviced. This allows the locking member to be maintained or replaced without disassembling the entire thrust reverser assembly, thereby maintaining ease of maintenance while ensuring reliability during operation.
3Strength
If a locking mechanism is added to prevent deflection, then the structural strength is improved, but the device complexity is worsened
Solution Approach 1:
The locking member is merged with the existing V-blade and V-groove assembly rather than being a completely separate mechanism. This integration allows the locking function to be achieved using existing structural components, minimizing the increase in device complexity while still providing the necessary strength prevention.
Solution Approach 2:
The locking member is designed to be actuated by the existing blocker door mechanism, utilizing the movement already present in the thrust reverser system. This self-actuating approach eliminates the need for additional actuators or control systems, thereby minimizing the increase in device complexity while still providing effective locking.
Data Source
AI summary
Aircraft systems having thrust reversers with locking assemblies are disclosed herein. In one embodiment, an aircraft system includes a fan casing and a thrust reverser attached to the fan casing. The fan casing includes a first member. The thrust reverser includes a nozzle inner wall, a second member proximate to the nozzle inner wall for engaging with the first member, and a locking member positioned proximate to the first member. The locking member is movable between (a) a first position in which the first member is positioned between the locking member and the second member such that the locking member inhibits disengagement of the first and second members, and (b) a second position in which the locking member does not inhibit disengagement of the first and second members. The first member can be a V-groove, and the second member can be a V-blade.