Sliding Component Dynamic Pressure Grooves Seal Leakage

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Solution Overview

Problem

Existing mechanical seals face challenges in maintaining seal integrity and preventing leakage, especially during initial rotation and at low speeds, due to the lack of effective dynamic pressure generation and lubrication, leading to increased friction, vibration, and unstable sliding properties.

Innovation Solution

The introduction of dynamic pressure-generating grooves and pumping areas with periodic linear indentation structures on the sealing faces of sliding parts, which communicate with the sealed fluid and generate a pumping action to control seal integrity and lubrication, ensuring sufficient lubrication and reducing leakage by forming a stable fluid film between the sealing faces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If dynamic pressure-generating grooves are provided to generate dynamic pressure during rotation, then sliding resistance decreases due to reduced friction, but leakage increases because the fluid film thickens and sealing faces break contact

Engineering Contradiction:
Improvesliding resistanceVSAvoidleakage
Core Design Contradiction:
Loss of energyVSLoss of substance

Solution Approach 1:

The pumping area is designed with a specific local structure (periodic linear indentations) within the dynamic pressure-generating groove to create a localized pumping action that controls fluid flow direction, allowing the fluid film to maintain appropriate thickness for both lubrication and sealing

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The periodic linear indentations in the pumping area change the fluid flow parameters by creating a pumping action that directs fluid flow, thereby controlling the fluid film thickness and pressure distribution to balance lubrication and sealing functions

Inventive Principle:
Principle #35Parameter changes

2Reliability

If dynamic pressure-generating grooves are provided to generate dynamic pressure, then wear is reduced during sliding part rotation, but leakage increases due to lack of seal integrity control

Engineering Contradiction:
Improvewear resistanceVSAvoidleakage
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The pumping area with periodic linear indentations is locally structured within the groove to create a pumping action that controls fluid flow, enabling the system to simultaneously achieve wear protection through dynamic pressure and leakage prevention through controlled seal integrity

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The pumping action created by the periodic linear indentations provides a feedback mechanism that regulates fluid flow between the sealing faces, maintaining optimal fluid film thickness for both wear protection and leakage prevention

Inventive Principle:
Principle #23Feedback

3Speed

If rotation begins from standstill, then sealing operation starts, but sufficient lubrication cannot be introduced until dynamic pressure is generated, leading to increased torque and unstable sliding properties

Engineering Contradiction:
Improverotational speedVSAvoidsliding stability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The pumping area with periodic linear indentations performs preliminary action by actively pumping lubricating fluid into the sealing face gap from standstill, establishing sufficient lubrication before dynamic pressure generation, thereby reducing starting torque and stabilizing sliding properties during acceleration

Inventive Principle:
Principle #10Preliminary action

4Loss of energy

If dynamic pressure is generated between sealing faces, then lubrication is improved, but seal tightness deteriorates because fluid escapes from the positive pressure portion

Engineering Contradiction:
ImprovefrictionVSAvoidfluid outflow
Core Design Contradiction:
Loss of energyVSLoss of substance

Solution Approach 1:

The pumping action created by the periodic linear indentations changes the fluid flow parameters by directing fluid flow and controlling pressure distribution, allowing dynamic pressure generation for lubrication while preventing fluid escape through the structured pumping mechanism

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

This solution prevents leakage when stopped, provides stable sliding properties at low speeds, and optimizes seal integrity by controlling fluid flow, reducing friction and improving sliding performance during rotation, even at high pressures and speeds.

Implementation Method 1

a plurality of dynamic pressure-generating grooves for generating dynamic pressure via the relative rotational sliding of the stationary ring and the rotating ring

Methodology Applied
Scientific EffectDynamic pressure generation: Hydrodynamic Cavitation

Implementation Method 2

pumping areas for generating pumping action via the relative rotational sliding of the stationary ring and the rotating ring

Methodology Applied
Scientific EffectPumping action: Pump

Implementation Method 3

the pumping areas having periodic linear indentation structures

Methodology Applied
Scientific EffectPeriodic structure pumping effect: Peristalsis

Data Source

PatentEP2754930B1Sliding component
Publication Date: 2017.06.14 EAGLE INDS
  • EP2754930B1 patent drawingFigure 1
  • EP2754930B1 patent drawingFigure 2
  • EP2754930B1 patent drawingFigure 3(a)~3(b)

AI summary

{Problem} To provide sliding parts that do not leak when stopped, that operate under fluid lubrication and prevent leakage when rotating, including during initial rotation, and that are capable of having a balance seal tightness and lubrication. {Solution} A plurality of dynamic pressure-generating grooves for generating dynamic pressure via the relative rotational sliding of the stationary ring and the rotating ring is formed in a circumferential direction on a sealing face of one of a stationary ring and the rotating ring so as to communicate with a sealed fluid-containing space, and pumping areas for generating pumping action via the relative rotational sliding of the stationary ring and the rotating ring are formed within the dynamic pressure-generating grooves.