Segmented Thrust Reverser for Turbojet Engine Maintenance

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Solution Overview

Problem

The O-type thrust reverser for turbojet engines is time-consuming to operate due to the need to remove the thrust reverser mobile unit, which hampers engine change operations, while D-type reversers have aerodynamic inefficiencies and increased fuel consumption due to obstacles in the cold air stream.

Innovation Solution

A gated thrust reverser design combining O-type and D-type features, with a cylindrical thrust reverser wheel set having semi-cylindrical half-parts connected by a removable device, allowing sliding motion and pivotable outer cowls for maintenance access, and a cradle connecting the wheel set to the pylon for sliding, along with anti-rotation devices and screw-nut connecting mechanisms for efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If O-type thrust reverser is used, then aerodynamic efficiency is improved, but engine change time increases due to removal requirement

Engineering Contradiction:
Improvefuel consumptionVSAvoidengine change time
Core Design Contradiction:
Loss of energyVSLoss of time

Solution Approach 1:

The thrust reverser mobile unit is divided into two separable half-parts (first half-part and second half-part) connected by a removable connecting device. This segmentation allows the half-parts to be quickly disconnected and removed during engine changes, eliminating the time penalty of removing the entire thrust reverser while maintaining the aerodynamic efficiency of the O-type design when connected.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If D-type thrust reverser is used, then engine access is improved, but aerodynamic efficiency deteriorates due to obstacles in cold air stream

Engineering Contradiction:
Improveengine accessVSAvoidfuel consumption
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The thrust reverser mobile unit is segmented into two half-parts that can be separated. When engine maintenance is required, the half-parts can be disconnected and moved aside to provide clear access to the engine, replicating the D-type advantage. When connected, the O-type smooth structure is maintained to preserve aerodynamic efficiency and reduce fuel consumption.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The thrust reverser mobile unit transitions between two dynamic states: connected (O-type configuration for aerodynamic efficiency) and separated (D-type configuration for engine access). This dynamic adaptability allows the system to optimize for either aerodynamic performance or maintenance accessibility depending on operational requirements.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If thrust reverser mobile unit is removed for engine change, then engine replacement is possible, but operational time increases

Engineering Contradiction:
Improveengine replacement capabilityVSAvoidoperational time
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The removable connecting device enables quick segmentation of the thrust reverser mobile unit into separable half-parts. This allows maintenance personnel to rapidly disconnect and remove only the necessary components during engine changes, rather than removing the entire thrust reverser assembly, thereby reducing operational time while maintaining full engine replacement capability.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3732360B1Grid-type thrust reverser for turbojet engine
Publication Date: 2023.06.07 SAFRAN NACELLES
  • EP3732360B1 patent drawingFigure 1~3
  • EP3732360B1 patent drawingFigure 4~6
  • EP3732360B1 patent drawingFigure 7~8

AI summary

The invention concerns a grid-type thrust reverser (22) for a turbojet engine, the reverser comprising a moving O-shaped thrust reverser body (30) that is generally cylindrical in shape around a longitudinal central axis (A) and that comprises an inner wall (34) designed to delimit a cold air stream, with an inner structure that surrounds the turbojet engine, the movable thrust reverser body (30) being mounted so as to be able to slide along the longitudinal central axis (A) between a direct jet position in which the outer cowl (32) covers the thrust reverser grids (28), and a thrust-reversal position in which the outer cowl (32) uncovers the thrust reverser grids (28), characterised in that the movable thrust reverser body (30) comprises a first half-portion (48) and a second half-portion (50) that are mounted so as to each pivot about a longitudinal pivot axis (B), between a closed position and an open gullwing position for removing the turbojet engine, via the cradle (40).