Sealing Face Dimples with Directional Projections for Leakage Control
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Solution Overview
Problem
Mechanical seals with smooth sealing faces experience leakage due to cavitation-induced streak-like fluid flows, which are challenging to control, especially under varying differential pressures between the inner and outer periphery.
Innovation Solution
The introduction of stripe-shaped projections with directionality at the bottom of dimples on the sealing faces, acting as geometrical barriers to control the streak-like flow and prevent leakage, along with continuous grooves that release positive pressure and extend cavitation formation areas, allowing fluid to be returned to the high-pressure side.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If smooth sealing faces are used to reduce friction, then lubrication performance is improved, but sealing performance deteriorates due to uncontrolled cavitation-induced fluid flow
Solution Approach 1:
The sealing face is divided into different functional zones: a cavitation formation area with stripe-shaped projections for fluid control, and other areas with smooth surfaces for low friction. This local differentiation allows simultaneous optimization of lubrication and sealing performance in different regions.
Solution Approach 2:
The cavitation phenomenon, which causes harmful streak-like fluid flow, is converted into a beneficial mechanism by deliberately creating a cavitation formation area. The stripe-shaped projections within this area control the cavitation-induced flow to redirect fluid toward the high-pressure side, transforming the harmful effect into a sealing enhancement mechanism.
2Reliability
If pumping mechanisms are added to push back leaked fluid, then sealing performance is improved, but device complexity increases
Solution Approach 1:
The sealing system uses the cavitation phenomenon and stripe-shaped projections to automatically redirect leaked fluid back to the high-pressure side without external pumping mechanisms. The structure self-regulates fluid flow based on the pressure differential and cavitation dynamics, eliminating the need for additional active components.
Solution Approach 2:
The invention extracts and utilizes the natural cavitation phenomenon that occurs in hydrodynamic sealing, separating it from the main sealing surface design. By creating a dedicated cavitation formation area with stripe-shaped projections, the system harnesses this phenomenon for fluid control without adding complex pumping mechanisms.
3Reliability
If stripe-shaped projections are added to control cavitation flow, then sealing performance is improved, but manufacturing precision requirements increase
Solution Approach 1:
The stripe-shaped projections are designed to work dynamically with the cavitation phenomenon and fluid flow. Their function emerges from the interaction between the projections, cavitation bubbles, and streak-like flow rather than requiring extremely precise static geometry. The system adapts to varying operating conditions through the dynamic cavitation process.
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 effectively prevents leakage regardless of differential pressure levels by controlling the streak-like flow and ensuring fluid is redirected to the high-pressure side, enhancing the sealing performance and reducing fluid loss.
Implementation Method 1
cavitation occurring in the fluid also forms a phase between them
Implementation Method 2
generate dynamic pressure between the sealing faces by means of rotation to create the so-called hydrodynamic lubrication state where the surfaces slide against each other with a liquid film in between
Implementation Method 3
generate dynamic pressure between the sealing faces by means of rotation
Data Source
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AI summary
{Technical Problem} The object is to provide a sliding component that can prevent leakage regardless of the level of differential pressure between the inner periphery and outer periphery of the sealing face by controlling the streak-like flow of fluid due to cavitation that occurs in a dimple or other concaved part formed on the sealing face. {Solution to Problem} The sliding component is characterized in that dimples are provided on one sealing face of a pair of sliding parts that mutually slide relative to each other, and stripe-shaped projections with directionality are provided in a cavitation formation area in each dimple.