Sectorised Aircraft Engine Casing Groove for Modular Maintenance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing propulsion unit assemblies for aircraft turbojets require the entire annular groove to be replaced in case of damage, leading to increased maintenance duration and material wastage, as well as disproportionate stress and wear on certain areas.

Innovation Solution

The intermediate casing extension is segmented into angular sectors that can be replaced individually, allowing for varying materials and designs based on stress levels, with a junction ferrule connecting these sectors to form an annular downstream connecting end, enabling efficient maintenance and reduced wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the entire annular groove is replaced in case of damage, then the structural integrity is maintained, but the maintenance duration increases and material is wasted

Engineering Contradiction:
Improvestructural integrityVSAvoidmaintenance duration
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The annular groove is divided into multiple replaceable segments that can be individually replaced when damaged, rather than replacing the entire annular groove structure. This segmentation allows for quick replacement of only the affected segment, significantly reducing maintenance time while maintaining structural integrity through the modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different materials and designs can be applied to different segments of the annular groove based on their specific stress levels and functional requirements. This allows for optimized local properties where high-wear areas receive more durable materials while other areas use lighter or more cost-effective materials, reducing overall material waste during partial replacements.

Inventive Principle:
Principle #3Local quality

2Reliability

If the entire annular groove is replaced in case of damage, then the structural integrity is maintained, but material wastage increases

Engineering Contradiction:
Improvestructural integrityVSAvoidmaterial wastage
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The annular groove is divided into multiple replaceable segments that can be individually replaced when damaged, rather than replacing the entire annular groove structure. This segmentation allows for replacement of only the affected segment, significantly reducing material wastage while maintaining structural integrity through the modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The segmented design allows the undamaged portions of the annular groove to be retained and reused, while only the damaged segment is discarded and replaced. This selective replacement approach minimizes material wastage by preserving functional components.

Inventive Principle:
Principle #34Discarding and recovering

3Ease of manufacture

If uniform material is used for the entire annular groove, then manufacturing is simplified, but wear resistance is insufficient in high-stress areas

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidwear resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

Different materials and designs can be applied to different segments of the annular groove based on their specific stress levels and functional requirements. This allows for optimized local properties where high-wear areas receive more durable materials while other areas use lighter or more cost-effective materials.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The annular groove can incorporate different materials in different segments, creating a composite structure that optimizes wear resistance in high-stress areas while maintaining ease of manufacture through standardized segment designs. Each segment can be manufactured separately with appropriate materials and then assembled into the complete annular groove.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP2072397B1Intermediate casing extension for an aircraft jet engine, comprising a sectorised annular groove for receiving nacelle covers
Publication Date: 2015.02.11 SN DETUDE & DE CONSTR DE MOTEURS DAVIATION (S N E C M A)
  • EP2072397B1 patent drawingFigure 1
  • EP2072397B1 patent drawingFigure 2
  • EP2072397B1 patent drawingFigure 3~4

AI summary

The invention relates to an extension (30) of an intermediate casing for an aircraft turbojet engine, designed to project downstream from an outer ferrule of the intermediate casing. This extension comprises an annular downstream connecting end (64) forming an annular groove (66) open radially outwards, intended to receive nacelle cowlings. According to the invention, the annular downstream connecting end (64) is formed using a plurality of angular sectors (76a, 76b).