Noncontacting Intershaft Seal Ring Using Magnetic Separation

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Solution Overview

Problem

Existing sealing systems in rotating machinery face challenges in maintaining effective sealing while minimizing contact-related effects such as heat and wear, especially under extreme operational conditions.

Innovation Solution

A noncontacting intershaft seal system is introduced, which includes an outer and inner shaft with axially spaced plates defining a gland opening. A ring, configured to expand under rotational forces, is disposed in the gland opening, and force generating elements, such as magnetic or hydrodynamic systems, are used to maintain separation between the ring and the plates, reducing contact-related issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If contact seals are used to maintain sealing between shafts, then sealing effectiveness is improved, but heat generation and wear increase

Engineering Contradiction:
Improvesealing effectivenessVSAvoidheat generation and wear
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces traditional mechanical contact seals with a magnetic coupling system where magnetic forces transmit torque between shafts without physical contact. This substitution eliminates friction-based heat generation and wear while maintaining sealing effectiveness through the non-contact magnetic field interaction.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a magnetic field as an intermediary between the two shafts to transmit rotational force. The magnetic coupling acts as a mediator that allows torque transmission across the seal interface without direct mechanical contact, thereby preventing wear and heat generation while maintaining functional connectivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If seal faces are loaded to improve sealing, then sealing performance is improved, but heat and wear are generated

Engineering Contradiction:
Improvesealing performanceVSAvoidheat generation
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent replaces loaded mechanical seal faces with a magnetic coupling system that transmits torque through magnetic attraction and repulsion forces. This eliminates the need for high contact pressure on seal faces, thereby preventing heat generation from friction while maintaining effective sealing through the non-contact magnetic interaction.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If traditional seals are used, then sealing is maintained, but contact-related wear reduces service life

Engineering Contradiction:
ImprovesealingVSAvoidservice life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent replaces traditional mechanical seals with a magnetic coupling system that eliminates physical contact between rotating components. By using magnetic fields to transmit torque without friction, the system eliminates wear mechanisms that limit service life, thereby extending operational duration while maintaining effective sealing between shafts.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If sealing systems are designed for extreme conditions, then operational reliability is improved, but complexity increases

Engineering Contradiction:
Improveoperational reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical seal assemblies with a simpler magnetic coupling system. The magnetic coupling consists of basic magnetic elements that can be integrated into the shaft structure, eliminating the need for complex seal faces, springs, and adjustment mechanisms while maintaining reliability under extreme operational conditions.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 effectively reduces heat generation and wear, leading to longer service life and enabling higher operating speeds and pressures, thus extending the operational range of the machinery.

Implementation Method 1

The end plates include force generating elements that generate desirable forces to separate the ring from the end plates, reducing contact related heat generation and wear

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Implementation Method 2

A split ring is disposed in the gland opening and operates to expand during rotation to engage and rotate with the outer shaft

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP4108959B1Non-contacting intershaft seal system
Publication Date: 2025.04.23 HONEYWELL INTERNATIONAL INC
  • EP4108959B1 patent drawingFigure 1
  • EP4108959B1 patent drawingFigure 2
  • EP4108959B1 patent drawingFigure 3

AI summary

A noncontacting intershaft seal system (58) includes force generating mechanisms (88, 92, 100, 106, 108) to reduce contact related effects. A sealing system (58) includes an outer shaft (41) that has a hollow interior (70). An inner shaft (42) extends through the hollow interior (70) of the outer shaft (41). Spaced apart end plates (72, 74) encircle and rotate with the inner shaft (42). A gland opening (78) is defined between the inner (42) and outer (41) shafts and between the end plates (72, 74). A ring (80) is disposed in the gland opening (78). The end plates (72, 74) and/or the ring (80) include force generating elements (88, 92, 100, 106, 108) that generate force to separate the ring (80) from the end plates (72, 74), reducing contact related heat generation and wear.