Monobloc Thrust Reverser Frame Design

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Solution Overview

Problem

Existing thrust reversers for dual-flow turbojet engines in aircraft nacelles are complex and costly to manufacture, with frames that require assembly of multiple parts and suffer from reduced efficiency due to gaps between deviation grids.

Innovation Solution

A monobloc frame design for the thrust reverser, made from a single piece of material, which includes a flared trunk wall and a radially extending annular wall, with actuators crossing axial orifices in one of the walls, simplifying assembly and maintaining mechanical integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple parts are assembled to form the thrust reverser frame, then the frame can accommodate actuators and support grids, but the manufacturing complexity and cost increase

Engineering Contradiction:
Improveframe functionalityVSAvoidframe assembly complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges multiple frame components into a single monobloc structure that integrates the upstream fixed part, downstream annular support, and actuator mounting features. This single piece framework eliminates the need to assemble multiple separate parts, reducing manufacturing complexity while maintaining all necessary functions for supporting deflection grids and accommodating actuators

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If grids are positioned close to the outer wall to maximize length, then flow deflection efficiency improves, but the fairing radius must be large which reduces grid length

Engineering Contradiction:
Improveflow deflection efficiencyVSAvoidgrid length
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent positions the deflection grids in an oblique arrangement that extends diagonally through the thrust reverser structure, utilizing three-dimensional space more effectively. This oblique positioning allows the grids to achieve both sufficient length for effective flow deflection and optimal proximity to the outer wall, resolving the geometric constraint between fairing radius and grid length

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If grids are spaced apart to accommodate actuator movement, then actuator installation is possible, but gaps reduce flow deflection efficiency

Engineering Contradiction:
Improveactuator installationVSAvoidflow deflection efficiency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent designs the framework with integrated actuator mounting features and pathways that allow actuators to be nested within or alongside the grid structure rather than requiring gaps between grids. The actuator mounting means are incorporated into the monobloc frame design, enabling actuator installation while maintaining continuous grid surfaces for optimal flow deflection efficiency

Inventive Principle:
Principle #7Nested doll (Nesting)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The monobloc frame design simplifies the manufacturing process, reduces assembly complexity, and maintains mechanical integrity while optimizing the flow of the secondary air flow through the deviation grids during thrust inversion.

Implementation Method 1

A monobloc frame design for the thrust reverser, made from a single piece of material, which includes a flared trunk wall and a radially extending annular wall, with actuators crossing axial orifices in one of the walls, simplifying assembly and maintaining mechanical integrity.

Methodology Applied
Scientific EffectMechanical integrity:

Implementation Method 2

elements for deflecting a secondary flow from the turbojet through the grids when the cowlings are in their downstream position

Methodology Applied
Scientific EffectFlow deflection:

Data Source

PatentEP4153856B1Thrust reverser for an aircraft bypass turbojet engine nacelle
Publication Date: 2025.05.14 SAFRAN NACELLES
  • EP4153856B1 patent drawingFigure 1~2
  • EP4153856B1 patent drawingFigure 3~4
  • EP4153856B1 patent drawingFigure 5~6

AI summary

Thrust reverser (30) for an aircraft bypass turbojet engine nacelle, said thrust reverser having a generally annular shape around an axis and comprising an annular frame (34) for securing deflection grids (38), said frame (34) comprising: - a first frusto-conical wall (52) widening in the downstream direction and comprising an upstream peripheral edge (52a) configured to be attached to a casing of the turbojet engine, and a downstream peripheral edge (52b) extending in the continuation of the wall and being used to secure the upstream ends (38a) of the grids (38), and - a second annular wall (54) which extends radially outwards from an outer frusto-conical face (52c) of the first wall (52), the first and second walls (52, 54) being integrally formed and the second wall (54) comprising axial openings (64) through which actuators (44) pass.