Sliding Component Recess Structure for Long-Life Lubricity

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Solution Overview

Problem

The existing sliding components with dimples for reducing friction and preventing fluid leakage face a decline in lubricity due to wear over time, as the depth of dimples decreases, leading to inadequate fluid retention and potential leakage.

Innovation Solution

A sliding component design featuring recessed portions and hollow portions that maintain lubricity by forming new recessed portions as the surface wears, with throttle passages allowing fluid and debris movement, and strategically positioned hollow portions to ensure consistent volume and fluid retention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dimples are provided in the sliding surface to reduce friction and prevent fluid leakage, then lubricity is improved, but the depth of dimples decreases due to wear over time, leading to decline in lubricity

Engineering Contradiction:
ImprovelubricityVSAvoidservice life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The invention transitions from a two-dimensional surface feature (dimples on the sliding surface) to a three-dimensional volume feature (hollow portions extending into the sliding member). This dimensional extension allows the lubricating fluid reservoir to replenish surface dimples during wear, maintaining consistent lubricity throughout the service life of the sliding component.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Quantity of substance

If dimples are made deeper to hold more sealed fluid, then fluid retention is improved, but wear debris accumulates more easily and manufacturing complexity increases

Engineering Contradiction:
Improvesealed fluid volumeVSAvoidstructure complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The invention divides the fluid retention system into multiple segments: surface dimples for immediate lubrication and subsurface hollow portions for fluid reservoir. This segmentation allows each component to perform its function optimally - surface dimples provide instant lubrication while hollow portions store additional fluid without accumulating excessive wear debris.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies different qualities to different regions: the sliding surface has shallow dimples that are easy to clean and maintain, while the subsurface region has larger hollow portions for fluid storage. This local differentiation optimizes both fluid retention and wear debris management without excessive overall complexity.

Inventive Principle:
Principle #3Local quality

3Duration of action of stationary object

If the volume of recessed portions is increased to maintain lubricity during wear, then lubricity sustainability is improved, but the sliding member thickness requirement increases

Engineering Contradiction:
Improveservice lifeVSAvoidsliding member thickness
Core Design Contradiction:
Duration of action of stationary objectVSLength of stationary object

Solution Approach 1:

The invention implements a nested structure where hollow portions are positioned beneath and aligned with surface dimples, creating a hierarchical arrangement. This nesting allows the system to maintain lubricity over extended service life by replenishing surface dimples from subsurface hollow portions, achieving long-duration lubricity without requiring excessive overall thickness.

Inventive Principle:
Principle #7Nested doll (Nesting)

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

This design sustains inter-sliding surface lubricity by maintaining a consistent volume of recessed portions and preventing wear debris accumulation, thus preventing a decline in sealability and lubricity even as the sliding surface wears.

Implementation Method 1

When the pair of sliding members rotate relative to each other, a sealed fluid is supplied to the dimples provided in the sliding member, dynamic pressure is generated between the sliding surfaces

Methodology Applied
Scientific EffectDynamic pressure: Pressure Increase

Implementation Method 2

the sliding surfaces can be slid with each other with a liquid film interposed between the sliding surfaces

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 3

throttle passages extending in the thickness direction allow the recessed portions and the hollow portions to communicate with each other

Methodology Applied
Scientific EffectFluid flow:

Data Source

PatentEP4253779B1Sliding component and method for manufacturing sliding component
Publication Date: 2024.12.18 EAGLE INDS
  • EP4253779B1 patent drawingFigure 1
  • EP4253779B1 patent drawingFigure 2
  • EP4253779B1 patent drawingFigure 3

AI summary

Provided are a sliding component capable of sustaining inter-sliding surface lubricity for a long time and a method for manufacturing a sliding component. At least one of a pair of sliding members 10 and 20 is provided with: a group of recessed portions 22A including a plurality of recessed portions 22 and 22' formed in a sliding surface 21 of the sliding member 20; and a plurality of hollow portions 24a to 24d and 24a' to 24d' formed inside the sliding member 20 so as to be out of alignment with the recessed portions 22 and 22' in a thickness direction of the sliding member 20. The sliding member 20 is further provided with the hollow portions 24a to 24d and 24a' to 24d' disposed so as to generate at least part of a new group of recessed portions until the sliding member 20 is worn by the thickness of deepest one of the recessed portions 22 and 22'.