Hidden Thrust Reverser Link Arm Fitting Design

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The existing thrust reverser blocker door link arm and fitting in gas turbine engines cause duct losses and increase thrust specific fuel consumption (TSFC) due to their design, which obstructs airflow and reduces efficiency.

Innovation Solution

A linkage system is introduced that includes a thrust reverser link arm and a fitting arrangement, where the fitting is positioned to not extend into the bypass flow path, allowing for efficient airflow and reducing TSFC by minimizing obstruction, and a method for installing this system to a nacelle that maintains efficient airflow without opening the thrust reverser blocker door.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the fitting extends into the bypass flow path to provide structural support for the link arm, then the structural strength and stability are improved, but the airflow efficiency deteriorates and TSFC increases

Engineering Contradiction:

Improvestructural strengthVSAvoidTSFC

Core Design Contradiction:

StrengthVSLoss of energy

Solution Approach 1:

The fitting is extracted from the bypass flow path and repositioned to attach to the inner fixed structure surface, removing the source of airflow obstruction while maintaining the structural connection function between the link arm and the engine structure

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The fitting attachment location is moved from a radial extension into the flow path to a surface-mounted position on the inner fixed structure, changing the spatial dimension of attachment and eliminating interference with bypass airflow

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Loss of energy

If the fitting is repositioned to avoid the bypass flow path, then the airflow efficiency and TSFC are improved, but the ease of installation deteriorates due to limited access from the bypass flow path

Engineering Contradiction:

ImproveTSFCVSAvoidease of installation

Core Design Contradiction:

Loss of energyVSEase of manufacture

Solution Approach 1:

Instead of accessing the fitting installation location from the bypass flow path (traditional approach), the installation is performed from the opposite side through the core compartment, reversing the access direction to reach the repositioned fitting location

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The core compartment serves as an intermediary access route, allowing installation personnel to reach the repositioned fitting on the inner fixed structure from the opposite side of where the link arm operates

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP3293387B1Hidden thrust reverser blocker door link arm fitting

Publication Date: 2019.10.02 UNITED TECH CORP

Figure 1
Figure 2A
Figure 2B

AI summary

A linkage system (232; 432; 532; 632) for a nacelle (112) may comprise a pivot (330; 430; 530) configured to extend through a second aperture disposed in a link arm (256), a base member (310; 410; 510; 610), and a retaining member (320; 420; 520; 620) at least partially defining a first aperture and a cavity (342; 442; 542). The pivot (330; 430; 530) is configured to extend at least partially into the first aperture. The cavity (342; 442; 542) is configured to accommodate a portion of the link arm (256).