Thrust Reverser Blocker Door Slider Mechanism

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional thrust reverser designs in high bypass turbofan engines suffer from increased aerodynamic drag and reduced performance due to blocker doors and link arms that protrude into the duct flow path during normal operation, causing surface interruptions, duct leakage, and exposure to damage.

Innovation Solution

A thrust reverser assembly featuring a translating cowl and cascade with a pivotally coupled blocker door that pivots relative to the translating cascade, using a slider assembly and track to deploy the blocker door into the bypass duct, reducing drag and exposure during normal operation, and an actuator to translate the cowl and cascade in the aft direction for thrust reversal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the blocker door and link arms are used in conventional thrust reverser design, then the thrust reversal function is achieved, but aerodynamic drag increases and aerodynamic performance reduces during normal operation

Engineering Contradiction:
Improvethrust reversal functionVSAvoidaerodynamic drag
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The blocker door is extracted from the conventional fixed position and made movable through a slider assembly mechanism. During normal operation, the blocker door is completely removed from the bypass duct flow path, eliminating aerodynamic drag. When thrust reversal is needed, the slider assembly translates the blocker door into position to block the bypass duct and redirect flow through the cascade.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The blocker door transitions from a static component to a dynamic one that can translate between stowed and deployed positions. The slider assembly enables this dynamic movement, allowing the blocker door to be positioned optimally for both normal operation (stowed, minimal drag) and thrust reversal (deployed, effective flow blocking).

Inventive Principle:
Principle #15Dynamics

2Object-generated harmful factors

If the blocker door is covered by stowed blocker doors during normal operation, then the aerodynamic performance is maintained, but the blocker door is exposed to damage

Engineering Contradiction:
Improveaerodynamic performanceVSAvoiddamage exposure
Core Design Contradiction:
Object-generated harmful factorsVSObject-affected harmful factors

Solution Approach 1:

The translating cowl acts as an intermediary protective structure that covers the blocker door during normal operation. The cowl translates in the aft direction to expose the blocker door for thrust reversal, and during normal operation, it shields the blocker door from potential damage while maintaining smooth aerodynamic flow through the bypass duct.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If the translating cowl and translating structure are used, then the blocker door can be concealed during normal operation, but the device complexity increases

Engineering Contradiction:
Improvesurface interruptionsVSAvoidtranslating mechanism
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The translating cowl and translating cascade are merged into a single translating structure that moves together as one unit. This integration reduces the number of separate mechanisms needed, simplifying the overall system while still achieving the goal of concealing the blocker door during normal operation and exposing it for thrust reversal.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3029306B1Gas turbine engine and thrust reverser assembly therefor
Publication Date: 2021.07.07 RTX CORP
  • EP3029306B1 patent drawingFigure 1
  • EP3029306B1 patent drawingFigure 2
  • EP3029306B1 patent drawingFigure 3

AI summary

The present disclosure relates generally to a thrust reverser for a gas turbine engine. As a translating cowl (234A) is translated aft (240) from the nacelle (212) of the gas turbine engine, a cascade (234B) is also translated in the aft direction and a blocker door (234C) coupled to the cascade is pivoted into a fan duct (230), thereby diverting air in the fan duct through the cascade. In the stowed position, both the cascade and the blocker door are disposed radially outward of a radially inner wall of the nacelle and/or the translating cowl.