Twin Sealing Ring Assembly for Dry Gas Wear and Leakage Control
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Solution Overview
Problem
Sealing ring assemblies, particularly twin ring configurations, face challenges with high wear rates and fracture risks in the absence of lubricating oil, leading to uneven wear and increased leakage, which limits their operational life and effectiveness in maintaining a seal between high and low-pressure regions.
Innovation Solution
The proposed sealing ring assembly includes a first ring with an axially extending surface and a second ring with an inner radial surface interface, featuring a circumferential groove open to a low-pressure boundary and a pocket to receive gas from a high-pressure boundary, along with an anti-rotation feature to prevent azimuthal movement, all made from self-lubricating materials like graphite to enhance wear resistance and maintain a seal without liquid lubricants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If self-lubricating material is used in the sealing ring, then the seal can operate without liquid lubricant, but the wear rate is relatively high leading to gap formation and unacceptable leakage flow
Solution Approach 1:
The sealing ring is divided into multiple segments (first ring and second ring) that can move independently relative to each other. This segmentation allows the rings to self-adjust and maintain sealing contact despite wear, preventing gap formation and controlling leakage flow while operating without liquid lubricant.
Solution Approach 2:
The sealing ring uses dynamic elements including a spring that applies continuous radial force to maintain sealing contact, and allows axial and radial movement of the rings relative to each other. This dynamic adjustment compensates for wear and maintains sealing effectiveness without requiring liquid lubricant.
2Ease of operation
If self-lubricating material is used in the sealing ring, then the seal can function without lubricating oil, but uneven wear occurs leading to fracture risk
Solution Approach 1:
Dividing the sealing ring into multiple segments distributes the mechanical stress and wear across separate components. This prevents stress concentration that would lead to fracture, while allowing each segment to wear relatively evenly without liquid lubricant.
Solution Approach 2:
The spring element provides continuous radial force that cushions the sealing rings against uneven wear and mechanical shocks. This pre-applied supportive force prevents fracture by maintaining uniform contact pressure and absorbing stress variations during operation without liquid lubricant.
3Duration of action of stationary object
If the sealing ring wears down radially, then the seal functions for extended operation, but gaps form between portions of the seal increasing leakage
Solution Approach 1:
The dynamic configuration allows the sealing rings to move axially and radially relative to each other in response to wear. The spring continuously pushes the rings together, maintaining sealing contact even as material is removed over extended operational periods, preventing gap formation and leakage.
Solution Approach 2:
The sealing ring assembly is self-adjusting through the spring-loaded mechanism that automatically compensates for radial wear. As the rings wear down, the spring extends and maintains constant radial force, ensuring continuous sealing effectiveness without external intervention or liquid lubricant for hundreds or thousands of hours of operation.
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 reduces wear rates, minimizes fracture risks, and maintains an effective seal by balancing radial forces and pressure locking, thereby extending the operational life of the sealing ring assembly and reducing leakage between high and low-pressure regions.
Implementation Method 1
a self-lubricating material in which the wear rate is relatively high
Implementation Method 2
the wear rate is relatively high, the gap opens by an amount that results in unacceptable leakage flow
Implementation Method 3
a groove extending circumferentially along at least one of the radially outward surface of the extension and the inner radial surface of the second ring... configured to be open to a low-pressure boundary... a pocket that extends azimuthally in an outermost radial surface of the second ring. The pocket is configured to receive gas from a high-pressure boundary
Implementation Method 4
The piston includes an anti-rotation relief and the sealing ring assembly comprises an anti-rotation tab that engages with the anti-rotation relief to prevent substantial azimuthal movement of the sealing ring assembly
Data Source
AI summary
The present disclosure provides a sealing ring assembly having a first ring and a second ring, configured to seal a high-pressure region from a lower pressure region of a piston and cylinder device. Accordingly, the sealing ring assembly includes a high-pressure boundary and a low-pressure boundary. Each ring may be segmented, and the first and second rings interface along a surface. Along the surface at the interface, a groove open to the lower pressure region aids in pressure locking the sealing ring assembly. A pocket in the second ring allows for high pressure gas to aid in balancing radial forces on the sealing ring assembly. As the sealing ring wears, the first and second rings remain engaged with one another.