Magnetorheological Fluid Additives for Friction and Soft Settling

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Solution Overview

Problem

Magnetorheological fluids face issues with particle settling and wear when in contact with surfaces, as additives that reduce friction often exacerbate settling, leading to non-uniform particle distribution and increased shear forces required for re-suspension.

Innovation Solution

Incorporating an amine oleate salt and molybdenum disulfide into the magnetorheological fluid composition, with the amine oleate salt present at 0.4 to 0.6 weight percent and molybdenum disulfide at 1.0 to 7.0 weight percent, to reduce friction and improve anti-settling properties, thereby reducing wear and facilitating easier re-dispersion of particles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional friction reducing agents are added to magnetorheological fluids, then friction is reduced, but particle settling is exacerbated

Engineering Contradiction:
ImprovefrictionVSAvoidparticle distribution uniformity
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent introduces amine oleate salt as an intermediary substance that mediates between the friction reduction function and the anti-settling function. This surfactant adsorbs onto particle surfaces, providing both lubrication to reduce friction and steric/electrostatic stabilization to prevent settling, thus resolving the contradiction between these two opposing requirements

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a composite additive system combining amine oleate salt with molybdenum disulfide particles. This composite approach integrates the friction reduction properties of molybdenum disulfide with the surfactant properties of amine oleate salt, creating a synergistic effect that simultaneously reduces friction and prevents particle settling

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If particle settling is prevented, then uniform particle distribution is maintained, but friction increases

Engineering Contradiction:
Improveparticle distribution uniformityVSAvoidfriction
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The amine oleate salt acts as a mediator that allows particles to maintain uniform distribution through steric and electrostatic stabilization while simultaneously providing a lubricating film that reduces friction between particles and between particles and surfaces, thus preventing the trade-off between stability and friction

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If friction is reduced to minimize wear, then particle re-suspension becomes easier, but particle settling increases

Engineering Contradiction:
ImprovewearVSAvoidparticle settling
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The amine oleate salt serves as a dual-function intermediary that reduces friction to minimize wear while its surfactant properties provide steric and electrostatic stabilization to prevent particle settling, thus resolving the contradiction between wear reduction and settling prevention

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The composite of amine oleate salt and molybdenum disulfide creates a synergistic system where molybdenum disulfide provides extreme pressure and boundary lubrication to reduce wear, while amine oleate salt maintains particle suspension stability, achieving both wear reduction and settling prevention simultaneously

Inventive Principle:
Principle #40Composite materials

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 amine oleate salt and molybdenum disulfide combination significantly reduces low-temperature viscosity and friction, maintaining 75% of the viscosity at -20°C and 50% of the coefficient of friction compared to baseline fluids, while improving settling characteristics by allowing for 'soft settling' and easier re-dispersion with reduced shear forces.

Implementation Method 1

molybdenum disulfide particles, which work in compliment with traditional magnetorheological fluid additives... friction reducing agent comprising an amine oleate and molybdenum disulfide

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

The amine oleate salt and molybdenum disulfide combination significantly reduces low-temperature viscosity... maintaining 75% of the viscosity at -20°C

Methodology Applied
Scientific EffectViscosity modification:

Implementation Method 3

The particles become polarized in the presence of an applied magnetic field, and become organized into chains of particles within the fluid. The particle chains increase the apparent viscosity (flow resistance) of the fluid.

Methodology Applied
Scientific EffectMagnetorheological effect: Magnetorheological Fluid

Implementation Method 4

improving settling characteristics by allowing for 'soft settling' and easier re-dispersion with reduced shear forces

Methodology Applied
Scientific EffectSoft settling:

Data Source

PatentEP3424056B1Additive for magnetorheological fluids
Publication Date: 2024.04.03 LORD CORP
  • EP3424056B1 patent drawingFigure 1
  • EP3424056B1 patent drawingFigure 2
  • EP3424056B1 patent drawingFigure 3

AI summary

A magnetorheological fluid is provided having a reduced coefficient of friction and favorable settling characteristics. The fluid contains magnetically responsive particles, a carrier fluid, and an amine oleate salt.