Tubular Metal Sealing Ring Using Internal Pressure Equalization

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Solution Overview

Problem

Conventional metal sealing rings for forming metal-to-metal seals, such as in vacuum chambers or piston engines, require precise alignment and controlled clamping forces to ensure a reliable seal, and are prone to quality reduction due to uneven or excessive compression loads.

Innovation Solution

A metal sealing ring comprising a tubular metal body with an inlet tube for introducing internal pressure, allowing the body to deform and form a seal between opposing metal surfaces, with features like multi-metal sections, ridges, and a hydraulic medium to enhance seal integrity and adaptability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional metal sealing rings are used with flat circular gaskets crushed between metal surfaces, then a gas- or liquid-tight seal can be formed, but careful alignment and high clamping forces are required which increase device complexity and operational difficulty

Engineering Contradiction:
Improveseal integrityVSAvoidalignment precision
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The sealing ring incorporates a deformable body that can dynamically adjust its shape and size under internal pressure, transforming from a rigid structure requiring precise alignment to a flexible structure that adapts to surface irregularities. The body deforms against the opposing metal surfaces to form the seal, eliminating the need for careful alignment during installation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The sealing ring changes its physical parameters (shape, volume, cross-sectional area) in response to internal pressure. The body is adapted to increase in volume and deform under internal pressure, allowing the seal to form under varying pressure conditions without requiring precise initial alignment or excessive clamping forces.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If high clamping forces are applied to ensure seal quality, then a reliable seal can be formed, but uneven or excessive compression loads reduce seal quality and may damage the sealing ring

Engineering Contradiction:
Improveseal qualityVSAvoidsealing ring durability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The sealing ring incorporates a feedback mechanism where the internal pressure directly controls the deformation of the sealing body. The body deforms against the metal surfaces in response to internal pressure, automatically adjusting the sealing force to match the required level without exceeding it, thus preventing damage while ensuring seal quality.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The sealing ring uses internal hydraulic pressure (applied through the inlet tube) to deform the sealing body against the metal surfaces. This hydraulic action provides uniform, controlled compression forces that are distributed evenly across the sealing interface, avoiding localized stress concentrations that could damage the ring.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Adaptability or versatility

If the sealing ring is designed to be resilient and adaptable, then it can withstand varying pressures, but the structure becomes more complex requiring additional components like springs or pressurization systems

Engineering Contradiction:
Improvepressure range toleranceVSAvoidsealing ring structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The sealing ring merges the sealing function with the pressure-containing function into a single integrated structure. The tubular body serves both as the containment vessel for internal pressure and as the sealing element itself, eliminating the need for separate resilient components like springs or O-rings while maintaining adaptability to varying pressures.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sealing ring uses a flexible tubular metal body with controlled wall thickness (0.1-10 mm, preferably 0.2-2 mm) that can elastically and plastically deform under internal pressure. This flexible shell structure provides resilience and adaptability to varying pressure conditions without requiring additional mechanical components.

Inventive Principle:
Principle #30Flexible shells and thin films

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 provides a reliable, adaptable metal-to-metal seal that can withstand varying pressures without breaking, maintaining seal integrity even after pressure relief and allowing for easier installation and reduced mechanical stress, improving seal quality and durability.

Implementation Method 1

the body is adapted to increase in volume by deforming plastically upon introduction of the internal pressure. The plastic deformation allows the internal pressure in the body to be relieved without breaking the seal.

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

The body may be wholly or partially filled with a hydraulic medium. The hydraulic medium may be silicone rubber.

Methodology Applied
Scientific EffectHydraulic pressure transmission: Pascal's Law

Data Source

PatentEP3987200B1Metal sealing ring and method of forming a metal-to-metal seal
Publication Date: 2023.09.13 TOKAMAK ENERGY
  • EP3987200B1 patent drawingFigure 1~4B
  • EP3987200B1 patent drawingFigure 5A~6B
  • EP3987200B1 patent drawingFigure 7

AI summary

A metal sealing ring (1) for forming a metal-to-metal seal between two opposing metal surfaces. The metal sealing ring (1) comprises a tubular metal body (3) and an inlet tube (7) extending from the body (3) for introducing an internal pressure into the body (3). The body is adapted to deform under the internal pressure against each of the opposing metal surfaces to form the seal (1).