Insulating Hydraulic Connection Body With Controlled Charge Dissipation

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Solution Overview

Problem

Hydraulic systems in aircraft face challenges in ensuring a seal between different fluid circuits while also dissipating electrical charges and withstanding mechanical and thermal stresses, as metal fittings are conductive and can lead to ignition risks and reduced service life due to concentrated stresses.

Innovation Solution

A central body made of electrically insulating material with a conductive printed circuit to manage electrical charges, using polymer or ceramic substrates with resistive ink for controlled electrical resistance, and a tubular junction element to connect hydraulic circuits without crimping, ensuring mechanical strength and sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metal fittings are used to ensure mechanical strength and sealing, then the hydraulic system can withstand mechanical and thermal stresses, but the electrical conductivity of metal fittings creates ignition risks and cannot dissipate electrical charges safely

Engineering Contradiction:
Improvemechanical strengthVSAvoidignition risk
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The hydraulic system is segmented into metallic parts (for mechanical strength and sealing) and insulating parts (for electrical isolation). The connection body separates the metallic upstream circuit from the metallic downstream circuit, preventing direct electrical contact while maintaining hydraulic connectivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An insulating connection body acts as an intermediary between metallic hydraulic fittings. This intermediary component provides electrical isolation while allowing mechanical force transmission and hydraulic fluid passage, thereby preventing ignition risks without compromising mechanical strength.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a polymer central body is used to provide electrical insulation, then electrical charges cannot circulate, but the central body concentrates mechanical stresses and reduces component lifespan

Engineering Contradiction:
Improveelectrical insulationVSAvoidservice life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The connection body uses composite construction combining polymer material (for electrical insulation) with reinforcing elements or geometric design features (for mechanical strength). This composite approach maintains electrical isolation while distributing mechanical stresses to extend service life.

Inventive Principle:
Principle #40Composite materials

3Reliability

If radial crimping operation is used to mount the central body, then electrical insulation is achieved, but specific tooling is required and the process becomes complex

Engineering Contradiction:
Improveelectrical insulationVSAvoidmounting process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The complex radial crimping operation and specific tooling requirements are extracted from the mounting process. The connection body is designed with integrated mounting features that allow standard installation methods, eliminating the need for specialized crimping tools and simplifying the assembly process.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If the central body meets stringent electrical, thermal, and chemical requirements, then proper function is achieved, but additional stresses are generated at connection points

Engineering Contradiction:
Improvefunctional performanceVSAvoidconnection stress
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The connection body employs local quality variations in material properties or structural features at different locations. Areas subject to high mechanical stress have enhanced strength characteristics, while areas requiring electrical insulation maintain insulating properties. This localized optimization reduces connection stresses without compromising overall functional performance.

Inventive Principle:
Principle #3Local quality

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 solution provides a sealed junction between hydraulic circuits, protects against electrical discharges, and extends the service life by separating mechanical and electrical functions, reducing the risk of ignition and leaks, while allowing for easy maintenance.

Implementation Method 1

the central body having a conductive printed circuit board in order to conduct part of the electrical charges circulating between the upstream hydraulic circuit and the downstream hydraulic circuit

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

the conductive circuit is made from a resistive ink... the resistance is within the following range [10 kOhm ; 100 MOhm]... Mixed solutions employing expanded metal and polymer components must therefore offer sufficient resistivity to absorb a certain electrical power in order to avoid any risk of ignition

Methodology Applied
Scientific EffectElectrical resistance: Electrical Resistance

Data Source

PatentEP3538803B1Connection body, fittings and hydraulic system for the passage of a fluid between two hydraulic circuits, associated method and mounting
Publication Date: 2022.03.02 PERMASWAGE SA
  • EP3538803B1 patent drawingFigure 1~2
  • EP3538803B1 patent drawingFigure 3A~3D
  • EP3538803B1 patent drawingFigure 3E~6

AI summary

The invention relates to a central body (3) for a hydraulic system (1) for fluid, comprising a frame (32) having a first tubular end (33) for connecting an upstream hydraulic circuit (2) comprising a first fitting (20), and a second tubular end (34) for connecting a downstream hydraulic circuit (4) comprising a second fitting (40), said central body (3) comprising a passage (35) passing through the frame (32) in order to convey the fluid coming from the upstream hydraulic circuit (2, 4) to the downstream hydraulic circuit (2, 4), said frame (32) being produced from an electrically insulating material, the central body (3) comprising a printed circuit having controlled electrical properties in order to conduct a part of the electrical charges flowing in the upstream hydraulic circuit (2) and the downstream hydraulic circuit (4).