Spring-Assisted Nacelle Cowl Hinge Mechanism

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Solution Overview

Problem

The existing methods for opening and closing turbojet engine cowls are labor-intensive and costly due to the large mass and wind resistance of the cowls, requiring multiple maintenance operators and increasing operational time, and existing fully automatic solutions are difficult to implement on existing nacelles without adding weight or damaging the aerodynamic skin.

Innovation Solution

An assistance device using a compression spring and lever system, integrated with the existing articulation of the cowl, provides a moment to assist in opening and closing the cowl, reducing the need for manual effort and minimizing weight addition, by using a gas or helical spring to assist the maintenance operator without requiring significant modifications to the nacelle design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If fully automatic cylinders are installed to operate the cowl, then automation is improved, but device complexity and weight increase significantly

Engineering Contradiction:
Improveautomation of cowl operationVSAvoidcomplexity of installation
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The invention extracts the essential function of automation (providing opening/closing force) from complex cylindrical actuators and implements it through a simplified spring mechanism integrated into the existing hinge structure, eliminating the need for complex mounting systems while maintaining automated operation

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The spring mechanism serves multiple functions: it provides the opening force, assists in closing, and integrates with the existing hinge structure. The same spring assembly fulfills both force generation and structural integration roles, reducing overall system complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Extent of automation

If fully automatic cylinders are installed to operate the cowl, then automation is improved, but weight increases

Engineering Contradiction:
Improveautomation of cowl operationVSAvoidweight of actuation system
Core Design Contradiction:
Extent of automationVSWeight of moving object

Solution Approach 1:

The invention replaces heavy, complex cylindrical actuators with a lightweight spring mechanism that, while simpler and shorter-lived in terms of maintenance, provides sufficient functionality for the application, significantly reducing weight

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The spring mechanism acts as a counterweight system, using elastic potential energy stored in the spring to counterbalance the weight of the cowl, eliminating the need for heavy motorized actuators

Inventive Principle:
Principle #8Anti-weight (Counterweight)

3Strength

If reinforcement is added to the cowl for cylinder attachment, then strength is improved, but weight and manufacturing complexity increase

Engineering Contradiction:
Improvestrength of cowl structureVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The invention merges the reinforcement function with the existing hinge structure. The hinge mounting points serve dual purposes: providing structural reinforcement and serving as attachment points for the spring mechanism, eliminating the need for separate reinforcement elements

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The existing hinge structure is made multi-functional by integrating the spring attachment to it, allowing the same structural elements to serve both as rotation joints and as reinforcement/actuation mounting points

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Ease of operation

If multiple maintenance operators are used to open the cowl, then ease of operation is improved, but loss of time and operational cost increase

Engineering Contradiction:
Improveease of manual operationVSAvoidtime for opening/closing operation
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The spring mechanism provides self-service by automatically generating the force needed to open and close the cowl, requiring minimal human intervention (only to initiate the motion), thereby reducing both time and labor costs

Inventive Principle:
Principle #25Self-service

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 assistance device allows a single maintenance operator to easily open and close the cowl, reducing operational time and costs while maintaining the aerodynamic integrity of the nacelle without adding significant weight or requiring new design layouts.

Implementation Method 1

a compression spring applied to said elbow piece, adapted to exert a moment on the hood fitting assistance when the hood is up

Methodology Applied
Scientific EffectCompression spring: Spring

Data Source

PatentEP3016861B1Device for assisting in the manoeuvring of a cover and turbojet engine nacelle equipped with same
Publication Date: 2017.05.31 SAFRAN NACELLES
  • EP3016861B1 patent drawingFigure 1~3
  • EP3016861B1 patent drawingFigure 4~5
  • EP3016861B1 patent drawingFigure 6~7

AI summary

The present invention concerns a device for assisting in the manoeuvring of a cover of a nacelle of a turbojet engine or similar. The assistance device comprises a joint collinear with an existing joint or hinge for a fitting of the cover (1, 2), the joint of the device being rigidly secured to an angled part (13-15) of which one end bears on the fitting (35, 38) of the cover (1, 2) and of which one point is hinged to a compression spring (17, 27) in order to apply assistance momentum to the fitting of the cover when the cover (1, 2) is raised. Application to nacelles of turbojet engines or similar.