Sliding Member Coating Embeds Foreign Matter

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Solution Overview

Problem

Bearing coatings with low elastic recovery ratios are needed to prevent foreign matter entry and maintain lubricity, as existing coatings with higher recovery ratios fail to embed foreign particles effectively, leading to seizing issues in diesel engines with heavier loads and longer maintenance intervals.

Innovation Solution

A sliding member with a coating layer composed of a resin composition including a binder resin, solid lubricant, and metal particles with a Young's modulus between 10 GPa and 100 GPa, and an elastic recovery ratio of less than 60%, where the metal particles have a specific inclination and shape to ensure efficient embedding of foreign matter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the coating layer has high elastic recovery ratio (greater than 60%), then the coating layer maintains its original shape after deformation, but foreign matter cannot be embedded in the coating layer and remains at the interface causing seizing

Engineering Contradiction:
Improveelastic recovery ratioVSAvoidseizing resistance
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent changes the elastic recovery ratio parameter from greater than 60% to less than 60% by adjusting the resin composition (using softer resins like polyamide or polyimide with specific molecular weight ranges and adding plasticizers). This parameter change enables the coating layer to plastically deform and embed foreign matter, resolving the seizing resistance problem while maintaining adequate shape recovery through the specific composition balance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite resin composition containing multiple components: binder resin (polyamide or polyimide with specific molecular weight), plasticizer (in controlled amounts), and potentially fillers. This composite structure allows the coating layer to achieve less than 60% elastic recovery ratio while maintaining coating integrity, enabling foreign matter embedding capability that prevents seizing.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the coating layer is made softer to enable foreign matter embedding, then seizing resistance improves, but the coating layer durability and load-bearing capacity may deteriorate

Engineering Contradiction:
Improveseizing resistanceVSAvoidcoating layer durability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent carefully controls the molecular weight of the binder resin (polyamide: 10,000-50,000; polyimide: 20,000-80,000) and limits plasticizer content to achieve the optimal elastic recovery ratio range. This precise parameter control ensures the coating is soft enough to embed foreign matter but maintains sufficient strength and durability for engine bearing applications under load.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates local quality differentiation within the coating layer through the resin composition design, where the binder resin provides structural integrity and load-bearing capacity while the plasticized regions enable plastic deformation and foreign matter embedding. This localized functional differentiation resolves the contradiction between softness for embedding and strength for durability.

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 effectively embeds foreign matter, maintaining lubricity and preventing seizing, with the elastic recovery ratio of less than 60% ensuring foreign particles are embedded quickly, reducing the time they are present and enhancing seizing resistance.

Implementation Method 1

the coating layer has an elastic recovery ratio of less than 60%

Methodology Applied
Scientific EffectPlasticity: Plasticity

Implementation Method 2

a solid lubricant... slip occurs between its crystal planes so that the stress of the resin composition is relaxed

Methodology Applied
Scientific EffectSolid lubrication: Lubrication

Implementation Method 3

foreign matter that has entered between the coating layer and the sliding surface of a partner member is efficiently embedded in the coating layer

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP3263932B1Sliding member
Publication Date: 2019.10.23 DAIDO METAL CO LTD
  • EP3263932B1 patent drawingFigure 1
  • EP3263932B1 patent drawingFigure 2(A)~2(B)
  • EP3263932B1 patent drawingFigure 3(A)~3(B)

AI summary

Disclosed herein is a sliding member that has a coating layer serving as a sliding surface thereof so that even when foreign matter enters between the coating layer and a partner member, smoothness between them is maintained to prevent the occurrence of seizing. When the coating layer has an elastic recovery ratio of less than 60%, foreign matter that has entered between the coating layer and the sliding surface of a partner member is efficiently embedded in the coating layer. When the coating layer is formed of a resin composition, the resin composition contains a binder resin, a solid lubricant, and metal particles having a Young's modulus of 10 GPa or more but 100 GPa or less.