UV Curable Resin Self-Lubricating Liner for Sliding Bearings

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Solution Overview

Problem

Existing self-lubricating sliding bearings face challenges such as inability to perform size adjustments through grinding or cutting due to fiber damage, low productivity with thermosetting acrylic resins, and limitations in PTFE content due to decomposition issues during thermoplastic resin processing, requiring surface roughening for adhesion.

Innovation Solution

An ultraviolet curable resin composition comprising a (meth)acrylate compound with an isocyanuric acid ring and polytetrafluoroethylene resin, allowing for high PTFE content, easy handling, and strong adhesion without surface roughening, enabling size adjustments through cutting or grinding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fibrous lubricating liner is used in an unlubricated sliding bearing, then low friction coefficient and high durability are achieved, but size adjustment through grinding or cutting becomes impossible because the fibers will be cut and the liner will not function

Engineering Contradiction:
ImprovedurabilityVSAvoidsize adjustment capability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention changes the physical state of the lubricating liner from fibrous to a solid lubricant-containing resin composition. This parameter change allows the liner to maintain its structural integrity during grinding and cutting operations while still providing self-lubrication properties, thus resolving the contradiction between durability and size adjustment capability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite resin composition containing solid lubricant (PTFE) combined with thermoplastic resin. This composite material provides both the durability of a cohesive structure and the self-lubricating properties of PTFE, while allowing post-manufacturing size adjustments through conventional machining operations

Inventive Principle:
Principle #40Composite materials

2Force

If thermosetting acrylic resin is used for self-lubricating coating, then high load capacity is achieved, but productivity decreases due to long curing time

Engineering Contradiction:
Improveload capacityVSAvoidcuring speed
Core Design Contradiction:
ForceVSProductivity

Solution Approach 1:

The invention replaces the thermal curing mechanism of thermosetting resins with a solid lubricant-containing thermoplastic resin system that cures through cooling rather than chemical reaction. This substitution eliminates the long curing time associated with thermosetting acrylic resins while maintaining high load capacity, thus resolving the contradiction between load capacity and productivity

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

Solution Approach 2:

The invention utilizes phase transition (freezing) of the thermoplastic resin from liquid to solid state to achieve curing. This phase change process occurs rapidly upon contact with the cooled sliding surface, providing high productivity while maintaining the structural integrity and load-bearing capacity required for heavy-duty applications

Inventive Principle:
Principle #36Phase transitions

3Reliability

If polytetrafluoroethylene is blended with thermoplastic resin for self-lubricating liner, then low friction coefficient is achieved, but PTFE content is limited to less than 30% by weight due to decomposition gas generation during high temperature processing

Engineering Contradiction:
Improvelubrication performanceVSAvoidPTFE content
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The invention applies the resin composition to the sliding surface in liquid or paste form before the sliding member is put into service. The thermoplastic resin then cures through freezing or cooling rather than high-temperature processing. This preliminary application approach allows incorporation of high PTFE content (30-50% by weight) without decomposition gas generation, as the curing occurs at low temperatures, thus resolving the contradiction between lubrication performance and PTFE content

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the curing temperature parameter from high temperature (thermoplastic processing) to low temperature (freezing or cooling). This parameter change eliminates the decomposition issue that limits PTFE content, allowing higher PTFE concentrations (30-50% by weight) to be used while maintaining excellent lubrication performance

Inventive Principle:
Principle #35Parameter changes

4Productivity

If thermoplastic resin is used for self-lubricating liner, then high productivity through injection molding is achieved, but surface roughening process is required for adhesion

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidsurface preparation process
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention utilizes the sliding surface itself as the curing substrate, where the thermoplastic resin cures through freezing or cooling directly on the sliding surface. This self-service approach eliminates the need for separate surface roughening processes, as the resin adheres effectively to the sliding surface through the curing process itself, thus resolving the contradiction between productivity and device complexity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention changes the adhesion mechanism from mechanical interlocking (requiring surface roughening) to thermal bonding through freezing or cooling. This parameter change in the curing process allows direct application to smooth sliding surfaces without requiring surface roughening, maintaining high productivity while reducing process complexity

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

The solution provides a self-lubricating liner with improved handling, high PTFE content, and strong adhesion, enabling efficient manufacturing of sliding members with low equipment costs and enhanced performance under high loads and temperatures.

Implementation Method 1

the resin composition is irradiated with ultraviolet rays to be cured and form a self-lubricating liner

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

a polytetrafluoroethylene resin as a solid lubricant

Methodology Applied
Scientific EffectSolid lubrication: Lubrication

Data Source

PatentEP3208283B1Ultraviolet curable resin composition, sliding member, and method for producing sliding member
Publication Date: 2020.07.29 MINEBEAMITSUMI INC
  • EP3208283B1 patent drawingFigure 1(a)~2
  • EP3208283B1 patent drawingFigure 3~4
  • EP3208283B1 patent drawingFigure 5(a)~6(b)

AI summary

There is provided a resin composition for a machinable liner of a sliding member. An ultraviolet curable resin composition for a self-lubricating liner contains a (meth)acrylate compound having an isocyanuric acid ring represented by the following formula, a polytetrafluoroethylene resin, and melamine cyanurate. In the formula (1), X is a group which contains an acryloyl group and is composed only of C, H, and O. Y and Z are groups each composed only of C, H, and O. The (meth)acrylate compound having the isocyanuric acid ring is contained in an amount of at least 20% by weight, a polytetrafluoroethylene resin is contained in an amount of 10 to 50% by weight, and the melamine cyanurate is contained in an amount of 30% by weight or less with respect to a total amount of the ultraviolet curable resin composition. The ultraviolet curable resin composition is suitable for a self-lubricating liner 24 of a spherical bearing 20 having an outer race 22 and an inner race 26.