Mechanical Seal Sliding Face Grooves to Prevent Leakage and Wear

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Solution Overview

Problem

Conventional sliding components with pressure release grooves between positive and negative pressure generation mechanisms on the low-pressure fluid side face issues with fluid leakage, leading to wear and friction heating, which compromises the sealing function over time.

Innovation Solution

A sliding component design featuring deep grooves on the opposite-to-sealed-fluid side that communicate with the sealed fluid side, incorporating positive and negative pressure generation mechanisms arranged efficiently with Rayleigh step and reversed Rayleigh step grooves, respectively, to actively introduce fluid across the entire sliding face, preventing leakage and wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pressure release grooves are provided between positive and negative pressure generation mechanisms on the low-pressure fluid side, then fluid can be vented from the high-pressure side, but fluid cannot be introduced to the low-pressure fluid side of the sliding face, causing liquid film depletion and wear

Engineering Contradiction:
Improvesealing functionVSAvoidwear and friction heating
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The groove structure is segmented into multiple functional zones: positive pressure generation grooves for fluid intake, negative pressure generation grooves for fluid retention, and pressure release grooves strategically positioned to vent only excess fluid while preserving the liquid film on the sliding face. This segmentation allows simultaneous achievement of sealing and lubrication functions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the sliding face are assigned different groove characteristics: the high-pressure side receives positive pressure generation grooves for active fluid introduction, the low-pressure side receives negative pressure generation grooves for fluid retention, and pressure release grooves are locally positioned to manage excess fluid without compromising the lubricating film. Each region's groove configuration is optimized for its specific functional requirement.

Inventive Principle:
Principle #3Local quality

2Reliability

If conventional groove configurations are used, then sealing function is maintained, but lubrication function deteriorates due to liquid film runoff

Engineering Contradiction:
Improvesealing functionVSAvoidservice life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

Negative pressure generation grooves are configured to create a suction effect that actively retains fluid on the low-pressure side of the sliding face before fluid can runoff. This preliminary fluid retention action ensures the liquid film remains in place to provide continuous lubrication throughout the service life of the mechanical seal.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The groove configuration ensures continuous presence of the lubricating liquid film on the sliding face through the combined action of positive pressure generation (fluid introduction), negative pressure generation (fluid retention), and controlled pressure release (excess fluid management). This continuity of lubrication action extends the service life by preventing wear and friction heating throughout operation.

Inventive Principle:
Principle #20Continuity of useful action

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 maintains the sealing function by preventing fluid film runoff, reducing torque and wear, and enhancing resistance to fluid adhesion, ensuring long-term sealing performance while providing efficient lubrication.

Implementation Method 1

the outer peripheral side of a sliding part 31 of an annular shape is the high-pressure fluid side, and the inner peripheral side is the low-pressure fluid side

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

grooves 36 of reversed Rayleigh step mechanisms 34 constituting negative pressure generation mechanisms on the low-pressure side

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 3

grooves 35 of Rayleigh step mechanisms 33 constituting positive pressure generation mechanisms

Methodology Applied
Scientific EffectRayleigh step mechanism:

Implementation Method 4

grooves 36 of reversed Rayleigh step mechanisms 34 constituting negative pressure generation mechanisms

Methodology Applied
Scientific EffectReversed Rayleigh step mechanism:

Data Source

PatentEP3540274B1Sliding component
Publication Date: 2023.01.04 EAGLE INDS
  • EP3540274B1 patent drawingFigure 1
  • EP3540274B1 patent drawingFigure 2
  • EP3540274B1 patent drawingFigure 3(a)~3(b)

AI summary

A sliding component takes in fluid actively to the entire sliding face to prevent wear, burn-damage, and the like due to friction heating between sliding faces while preventing leakage. At least one sliding face of sliding faces sliding relatively to each other of a pair of sliding parts of annular shapes is provided with positive pressure generation mechanisms 10 with positive pressure generation grooves 11 and negative pressure generation mechanisms 12 with negative pressure generation grooves 13. The positive pressure generation grooves 11 and the negative pressure generation grooves 13 are separated from the opposite-to-sealed-fluid side by a land R. Deep grooves 14 deeper than the groove depth of the positive pressure generation grooves 11 and the negative pressure generation grooves 13 are located at least on the opposite-to-sealed-fluid side of the positive pressure generation grooves 11 and the negative pressure generation grooves 13. The deep grooves 14 are provided in such a manner as to communicate at least with the sealed fluid side.