Colloidal Suspension for Low-Resistance Electrical Contact

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for transferring electrical current between rotating parts, such as machine components and high-voltage swivels, face issues like wear, resistance, and uneven current distribution due to contact surface irregularities and the use of environmentally undesirable materials like mercury, or suffer from increased wear and short circuits with colloidal suspensions.

Innovation Solution

A colloidal suspension of conducting particles in a non-conducting oil with specific viscosity and particle size, which provides insulating behavior at larger gaps and becomes highly conductive at smaller gaps, reducing resistance and ensuring stable current transfer without particle accumulation or short circuits, using oils like graphite-based penetrating oils.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a colloidal suspension of conducting particles is used to reduce resistance, then current transfer efficiency improves, but particle accumulation occurs leading to short circuits

Engineering Contradiction:
Improvecurrent transfer efficiencyVSAvoidparticle accumulation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the physical-chemical parameters of the colloidal suspension, specifically using particles with 1-1000 nm size and controlling viscosity between 1-10 mm²/s, which prevents particle accumulation while maintaining conductivity. This parameter optimization resolves the contradiction between improving current transfer and preventing harmful accumulation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite colloidal suspension system combining conducting particles with a specific viscosity-modified lubricant base, creating a stable mixture that maintains uniform distribution over time. This composite approach prevents particle settling while ensuring reliable electrical contact.

Inventive Principle:
Principle #40Composite materials

2Reliability

If contact pressure is increased to reduce resistance, then current transfer improves, but local deformation occurs increasing wear

Engineering Contradiction:
Improvecurrent transferVSAvoidcontact surface life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent changes the contact interface parameters by introducing a colloidal suspension that reduces contact resistance without requiring high contact pressures. The particle size and viscosity parameters are optimized to provide conductivity while minimizing mechanical stress on contact surfaces.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The colloidal suspension acts as an intermediary substance between contact surfaces, providing a conductive path that reduces the need for direct metal-to-metal contact under high pressure. This mediator protects the contact surfaces from deformation and wear.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If traditional conductive materials are used, then current transfer is achieved, but environmental toxicity and wear occur

Engineering Contradiction:
ImproveconductivityVSAvoidenvironmental toxicity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent uses non-toxic conducting particles (such as copper or aluminum oxides, or carbon-based materials) with specifically controlled size parameters of 1-1000 nm, replacing traditional toxic materials like mercury. The viscosity parameter of the carrier fluid is also optimized to ensure stable suspension without environmental harm.

Inventive Principle:
Principle #35Parameter changes

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

Enables efficient and stable high-current transfer with minimal voltage loss and reduced wear, preventing short circuits and maintaining conductivity over time, even under varying contact pressures and movements, while avoiding the drawbacks of traditional methods.

Implementation Method 1

a colloidal suspension of graphite particles in a lubricating liquid comprising a colloidal suspension of graphite particles

Methodology Applied
Scientific EffectColloidal suspension: Colloid

Implementation Method 2

providing an insulating behavior at gap widths between the first and second conductor above 0.5 mm and becoming highly conductive at gap widths below 0.1 mm

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 3

the lubricant comprising a non-conducting oil with a viscosity between 1 and 10 mm 2 the particle size being between 1 and 1000 nm

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 4

a colloidal suspension of graphite particles in a lubricating liquid comprising a colloidal suspension of graphite particles

Methodology Applied
Scientific EffectColloidal suspension: Colloid

Implementation Method 5

the liquid with particles as a colloidal suspension provides a stable and homogeneous medium allowing uniform current transmission

Methodology Applied
Scientific EffectBrownian motion: Brownian Motion

Data Source

PatentEP3149812B1Method for reducing the resistance between two conductors
Publication Date: 2020.07.08 ROTELCON
  • EP3149812B1 patent drawingFigure 1~2
  • EP3149812B1 patent drawingFigure 3~4
  • EP3149812B1 patent drawingFigure 5~6

AI summary

The invention relates to a method of transmitting a current from a first conductor to a second conductor, which conductors are in contacting relationship along a contact interface. The method is characterized by introducing a non-conducting liquid comprising conducting particles at the contact interface. Preferably the liquid comprises a penetrating oil with carbon particles in a colloidal suspension. It was found that the resistance between the conductors was strongly reduced. The conductors can be stationary in a contact interface but can move relative to one another in a sliding or rolling manner at the contact interface plane.