Sliding Surface Random Dimples for Lubrication and Sealing

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Solution Overview

Problem

Existing sliding components with aligned dimples face challenges in achieving uniform lubrication and sealing, as they tend to concentrate fluid at the radial center, leading to inefficient lubricating and sealing performance.

Innovation Solution

The implementation of sliding components with randomly arranged dimple groups of circular, elliptical, or oval shapes, partitioned by land portions, which are inclined radially to enhance fluid lubrication and sealing effects, allowing for adaptive performance across various sliding speeds and temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dimples are arranged and aligned in order on the sliding surface, then the sealing ability is improved, but the lubricating performance deteriorates due to fluid concentration at the radial center

Engineering Contradiction:
Improvesealing abilityVSAvoidlubricating performance
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies asymmetry by transitioning from aligned dimple arrangements to random dimple patterns. The random arrangement creates asymmetric fluid distribution pathways that prevent fluid concentration at the radial center, thereby improving lubricating performance while maintaining sealing ability through the distributed dimple coverage.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent implements local quality by varying the dimple arrangement pattern across different regions of the sliding surface. The random dimple distribution ensures that each local region contributes to both sealing and lubrication functions, with fluid being drawn into dimples throughout the surface rather than concentrating in specific areas.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If random dimples are arranged on the sliding surface to improve lubricating property, then the lubricating performance is improved, but the sealing performance is insufficient

Engineering Contradiction:
Improvelubricating propertyVSAvoidsealing performance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies parameter changes by optimizing the density, size, and depth parameters of the random dimples. By carefully controlling these parameters, the dimples are sized and distributed to effectively trap and retain fluid for lubrication while maintaining sufficient sealing pressure to prevent leakage, thus achieving both improved lubrication and adequate sealing performance.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If dimples are arranged with different inclination directions on outer and inner peripheral sides, then the sealing ability is improved, but the device complexity increases

Engineering Contradiction:
Improvesealing abilityVSAvoidconfiguration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies inversion by reversing the conventional approach of using directed, inclined dimples. Instead of aligning dimples in specific directions to achieve sealing, the patent uses random dimple orientations that naturally adapt to fluid flow patterns, simplifying the configuration while maintaining or improving sealing performance through the random distribution pattern.

Inventive Principle:
Principle #13The other way round (Inversion)

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 configuration synergistically improves both lubricating and sealing performances by blocking fluid circumferential movement and generating positive pressure, effectively adapting to different conditions through adjustable inclinations and shapes of dimple groups.

Implementation Method 1

positive pressure is generated by blocking circumferential movement of a fluid flowing into the sliding surface with the land portion

Methodology Applied
Scientific EffectPositive pressure generation: Pressure Increase

Implementation Method 2

a fluid lubricating effect and a sealing effect of the random dimple groups are synergistically increased

Methodology Applied
Scientific EffectFluid lubrication: Lubrication

Implementation Method 3

The sealing effect is also called as a pumping effect of suctioning the fluid from the leakage side to the sliding surface

Methodology Applied
Scientific EffectSuction effect: Suction

Data Source

PatentEP3627012B1Sliding component
Publication Date: 2022.01.19 EAGLE INDS
  • EP3627012B1 patent drawingFigure 1
  • EP3627012B1 patent drawingFigure 2
  • EP3627012B1 patent drawingFigure 3

AI summary

[Technical Problem] The present invention is to provide sliding components with which a lubricating effect and a sealing effect can be improved. [Solution to Problem] A pair of sliding components having sliding surfaces that slide with respect to each other, wherein at least the sliding surface S on one side includes a random dimple group 11 in which plural dimples 10 are randomly arranged, and at least one land portion 15 that partitions radial portions 11a, 11b of the random dimple group 11.