Tapered Seal Ring Assembly for Insert Blowout Resistance

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Solution Overview

Problem

Conventional composite bellows seal assemblies face challenges with insert blowout during high-pressure conditions and lack of weight reduction, as they rely heavily on friction and bonding agents to prevent insert displacement, which can lead to sealing system failure and increased mass.

Innovation Solution

The seal assembly features a seal ring shell with tapered portions and a shoulder portion to restrict insert movement, combined with a bonding element like room temperature vulcanized silicon rubber, allowing for secure engagement without excessive reliance on press fit, and includes a bellows connected via welding for enhanced stability and reduced mass.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If an insert is solely press fit without bonding, then weight is reduced, but the insert cannot be held in place under high pressure

Engineering Contradiction:
Improveinsert weightVSAvoidinsert retention
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The insert retention system is segmented into multiple independent features: tapered portions for axial restraint, shoulder portion for lateral restraint, and bonding element for sealing. This segmentation allows each feature to perform its specific function efficiently without relying on excessive press-fit force, reducing the need for heavy-duty fastening while maintaining reliability under high pressure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solution employs a composite retention mechanism combining mechanical features (tapered portions, shoulder) with a bonding element (epoxy or other bonding material). This composite approach allows the insert to be retained reliably through a combination of mechanical restraint and chemical bonding, enabling weight reduction while maintaining security against blowout under high-pressure conditions.

Inventive Principle:
Principle #40Composite materials

2Reliability

If bonding agent is added to prevent pressure encroachment, then insert retention is improved, but assembly weight increases

Engineering Contradiction:
Improveinsert retentionVSAvoidassembly weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The bonding element is applied locally only at the back wall interface between the shell and insert, rather than throughout the entire assembly. This localized application provides sufficient sealing and pressure containment at the critical interface while minimizing the total amount of bonding material used, thereby reducing the overall weight increase while maintaining improved insert retention.

Inventive Principle:
Principle #3Local quality

3Reliability

If friction between components is increased to prevent blowout, then insert retention is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveinsert retentionVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The tapered portions of the insert and corresponding tapered portions of the shell create a conical interface geometry. This curved/tapered surface design generates axial restraining force through the normal contact force at the inclined interface, providing effective blowout prevention through geometric constraint rather than relying on high friction coefficients or complex mechanical fastening systems.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 design effectively prevents insert blowout at high pressures and reduces assembly weight by up to 70% while maintaining operational stability and sealing integrity, addressing the limitations of conventional designs.

Implementation Method 1

a bonding element, such as an epoxy or bonding agent, is added to the back wall interface of the shell and insert to help prevent system fluid pressure unfavorably encroaching upon and affecting the interface

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

a portion of each of the insert tapered portion engages the respective seal ring shell tapered portion such that the seal ring shell tapered portions may restrict movement of the insert in a direction substantially along the inside diameter surface

Methodology Applied
Scientific EffectMechanical interference: Mechanical Force

Implementation Method 3

The seal ring shell may include a shoulder portion configured to restrict movement of the insert in a second axial direction

Methodology Applied
Scientific EffectGeometric constraint: Geometry

Implementation Method 4

The bellows may be connected to the seal ring shell via welding

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP3259505B1Blow-out resistant seal and assembly
Publication Date: 2021.09.29 EATON INTELLIGENT POWER LTD
  • EP3259505B1 patent drawingFigure 1
  • EP3259505B1 patent drawingFigure 2
  • EP3259505B1 patent drawingFigure 3

AI summary

A seal assembly (10) includes a seal ring shell (12) and an insert (14). The seal ring shell includes an inside diameter surface, and may also include a seal ring shell tapered portion that extends radially inwardly from the inside diameter surface. The insert includes an upper surface, and may also include an insert tapered portion. With embodiments, a portion of the upper surface of the insert contacts or operatively engages the inside diameter surface of the seal ring shell, and a portion of the insert tapered portion engages the seal ring shell tapered portion such that the seal ring shell tapered portion may impede movement of the insert in a direction substantially along the inside diameter surface (e.g., in an axial direction).