Self-Healing Bearing Surfaces Using Field-Controlled Lubricant Particles

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Solution Overview

Problem

Existing bearing devices face challenges such as wear and tear, leakage, and limited load-carrying capacity due to the reliance on controlled viscosity lubricants, which restricts the choice of lubricant properties and performance.

Innovation Solution

A bearing device utilizing a lubricant with particles that respond to magnetic or electric fields, where field generators create localized spatially varying fields to form agglomerates and obstruct lubricant flow, enhancing load-carrying capacity and reducing wear without the need for surface texturing or continuous pressurized lubricant supply.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If surface texturing is used to create recess and land areas for hydrostatic bearing, then load-carrying capacity is improved, but manufacturing precision requirements increase and wear resistance decreases

Engineering Contradiction:
Improveload-carrying capacityVSAvoidsurface finish precision
Core Design Contradiction:
ForceVSManufacturing precision

Solution Approach 1:

The patent replaces the mechanical surface texturing system with a magnetic field-based particle control system. Instead of relying on precisely machined recess and land areas, the invention uses magnetic field generators to manipulate particles in the lubricant, creating flow obstructions that generate hydrodynamic pressure. This substitutes mechanical precision requirements with magnetic field control, resolving the contradiction between load-carrying capacity and manufacturing precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the state of particles in the lubricant from suspended to agglomerated by applying magnetic fields. This parameter change allows dynamic control of flow obstructions without requiring fixed surface geometries. The particles can be moved between suspended and agglomerated states to adapt to different operating conditions, eliminating the need for precise surface texturing while maintaining load-carrying capacity.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If continuous pressurized lubricant supply is used in hydrostatic bearing, then wear is reduced, but reliability decreases due to external pressurized source malfunction risk

Engineering Contradiction:
ImprovewearVSAvoidbearing operation reliability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent implements a self-service lubrication system where the bearing generates its own hydrodynamic pressure through particle agglomerates formed by magnetic fields. The relative motion between bearing surfaces automatically drives lubricant flow through the particle obstructions, creating pressure without external pumps or pressurized sources. This eliminates the reliability issues associated with external pressurization systems while maintaining wear protection.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent introduces particles as an intermediary medium between the magnetic field generators and the lubricant flow. These particles act as movable obstructions that mediate the conversion of magnetic field energy into hydrodynamic pressure. The particles enable pressure generation without direct mechanical contact or external pressurization, resolving the contradiction between wear reduction and reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If hydrodynamic pressure is used for load bearing, then manufacturing complexity is reduced, but wear increases during start-up and slowdown when relative speed is low

Engineering Contradiction:
Improvesurface texturing complexityVSAvoidwear during start-up
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a dynamic particle control system where magnetic field generators can adjust particle agglomeration in real-time. During start-up and slowdown conditions, the magnetic fields can be intensified to create stronger flow obstructions that generate sufficient pressure even at low relative speeds. This dynamic adaptability allows the system to maintain load-carrying capacity across all operating conditions without the wear issues of traditional hydrodynamic bearings.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies magnetic fields to pre-position particles and create flow obstructions before full load conditions are reached. During start-up, the magnetic fields establish particle agglomerates that generate initial hydrodynamic pressure, preventing metal-to-metal contact. This preliminary action ensures protection during vulnerable low-speed periods before hydrodynamic pressure can naturally develop.

Inventive Principle:
Principle #10Preliminary action

4Quantity of substance

If particles are held in suspension in lubricant, then lubricant flow is maintained, but load-carrying capacity is limited without viscosity control

Engineering Contradiction:
Improvelubricant flowVSAvoidload-carrying capacity
Core Design Contradiction:
Quantity of substanceVSForce

Solution Approach 1:

The patent exploits a phase transition-like behavior where particles transition from a suspended state to an agglomerated state under magnetic fields. In the suspended state, particles maintain lubricant flow and lubrication. Under magnetic fields, particles agglomerate to create flow obstructions that generate hydrodynamic pressure for load bearing. This state transition allows the system to achieve both adequate lubricant flow and high load-carrying capacity without requiring viscosity control.

Inventive Principle:
Principle #36Phase transitions

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 effectively reduces wear and tear, minimizes leakage, and allows for the use of high-quality lubricants, improving load-carrying capacity and dynamic pressure creation while providing flexibility in lubricant selection and operation under varying conditions.

Implementation Method 1

the field generators are magnetic field generators configured to generate a localized spatially varying magnetic field which is configured to locally remove the particles from suspension by exerting a field force on the particles

Methodology Applied
Scientific EffectMagnetic field force on particles: Magnetic Field

Implementation Method 2

The local flow obstruction is configured to locally obstruct a flow of the lubricant through the bearing gap in an obstruction zone

Methodology Applied
Scientific EffectHydrodynamic pressure: Pressure Gradient

Implementation Method 3

enhancing load-carrying capacity and reducing wear without the need for surface texturing or continuous pressurized lubricant supply

Methodology Applied
Scientific EffectFriction reduction: Friction

Data Source

PatentEP4045805B1Self-healing bearing device using electric or magnetic fluids
Publication Date: 2024.02.21 BIFROST RES & DEV BV
  • EP4045805B1 patent drawingFigure 1A~1C
  • EP4045805B1 patent drawingFigure 1D
  • EP4045805B1 patent drawingFigure 2A~2C

AI summary

Bearing device comprising: - a first bearing surface and a second bearing surface which are moveable relative to one another and which face one another, wherein the first bearing surface and second bearing surface are separated by a bearing gap filled with a lubricant, wherein the lubricant comprises a carrier fluid and particles which respond to magnetic or electric fields, wherein said particles are suspended in the carrier fluid in the absence of magnetic or electric fields, - one or more field generators which are embedded in the first or second bearing surface, wherein the field generators are magnetic or electric field generators configured to generate a localized magnetic or electric field which is configured to locally remove the particles from suspension by exerting a field force on the particles, thereby forming a local flow obstruction on at least one of the bearing surfaces in the form of an agglomerate of previously suspended particles, wherein the local flow obstruction is configured to locally obstruct a flow of the lubricant through the bearing gap in an obstruction zone.