Aircraft Engine Combustion Chamber Injection System Axial Fixing

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Solution Overview

Problem

The existing aircraft engine combustion chamber injection systems experience significant wear and reduced service life due to vibratory activity at the collars, leading to premature failure.

Innovation Solution

The injection system is fixed to the deflector using clamping means that prevent axial movement between the first and second collars, employing a split retaining ring and peripheral retaining skirts to immobilize the system, reducing vibrations and wear on the fuel injector nozzle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If half-rings are used to fix the injection system to the deflector, then the assembly is easy to implement, but the fuel injector nozzle exhibits significant wear and reduced service life

Engineering Contradiction:

Improveease of assemblyVSAvoidservice life of fuel injector nozzle

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The retaining ring is divided into two separate half-rings that can be independently positioned and secured. This segmentation allows each half-ring to be optimally positioned to prevent axial movement of the collars while maintaining ease of assembly through modular installation

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A retaining ring is introduced as an intermediary component between the half-rings and the collars. This retaining ring prevents radial separation of the half-rings and provides a stable mounting structure that eliminates vibratory activity at the collars, thereby reducing wear on the fuel injector nozzle

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the injection system is freely mounted on the deflector, then assembly is simple, but vibratory activity at the collars amplifies wear on the fuel injector

Engineering Contradiction:

Improveease of assemblyVSAvoidvibratory activity causing wear

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The half-rings and retaining ring are pre-assembled into a complete fixing system before installation. This preliminary assembly ensures that the collars are properly positioned and constrained from the start, preventing vibratory activity and wear on the fuel injector nozzle while maintaining ease of operation through modular installation

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP2609372B1Combustion chamber for an aircraft engine, and method for attaching an injection system in a combustion chamber of an aircraft engine

Publication Date: 2019.07.03 SAFRAN AIRCRAFT ENGINES SAS

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AI summary

The invention relates to a combustion chamber in which the injection system is attached so as to prevent any axial motion of said injection system. To this end, the combustion chamber includes: a baffle (4) comprising at least one tubular portion (6) having a first upstream end (9) surrounded by a first radially projecting collar (10); and an injection system comprising at least one bowl (7) which in turn comprises a cylindrical portion (8) inserted into the tubular portion (6), the cylindrical portion (8) comprising a second upstream end (11) surrounded by a second radially projecting collar, the second collar (12) axially bearing against the first collar (10), wherein the combustion chamber comprises clamping means which axially clamp the first and the second collars (10, 12) against one another, and attachment means which retain the clamping means clamped on either side of the first and second collars (10, 12).