Interlocking Labyrinth Seal for Axial Rotor Retention

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Solution Overview

Problem

Conventional roller bearing seals, particularly contact seals, experience friction and wear due to direct contact between moving parts, leading to reduced fuel efficiency, heat generation, and maintenance issues, while noncontact labyrinth seals lack a locking mechanism to prevent axial motion and maintain a tortuous path, allowing contaminants and lubricant to escape.

Innovation Solution

A labyrinth seal design featuring an interlocking rotor and insert, along with a slinger, that encircles the rotation axis to form a tortuous path without direct physical contact, limiting axial motion and preventing the labyrinth from 'opening up', thus maintaining containment of contaminants and lubricant within the bearing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a contact seal is used to form a physical barrier, then sealing effectiveness is improved, but friction and wear increase leading to reduced fuel efficiency and maintenance issues

Engineering Contradiction:
Improvesealing effectivenessVSAvoidfuel efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent replaces the contact seal mechanical system with a noncontact labyrinth seal system. The labyrinth seal uses a tortuous path geometry to impede contaminant ingress and lubricant egress without requiring direct physical contact between sealing surfaces, thereby eliminating the friction and wear associated with contact seals while maintaining sealing effectiveness.

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

2Loss of energy

If a noncontact labyrinth seal is used to eliminate friction, then fuel efficiency is improved, but axial motion control is lost allowing the labyrinth to open up

Engineering Contradiction:
Improvefuel efficiencyVSAvoidlabyrinth path integrity
Core Design Contradiction:
Loss of energyVSStability of the object's composition

Solution Approach 1:

The patent introduces an intermediary axial locking mechanism that mediates between the noncontact labyrinth seal components. The locking feature, such as an axial locking groove and locking bead, acts as an intermediary structure that prevents axial displacement of the rotor relative to the seal housing, thereby maintaining the integrity of the labyrinth path while preserving the noncontact sealing advantage.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If a locking mechanism is added to the noncontact labyrinth seal to prevent axial motion, then labyrinth path integrity is improved, but device complexity increases

Engineering Contradiction:
Improvelabyrinth path integrityVSAvoidseal structure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent merges the locking mechanism with the existing labyrinth seal structure. The axial locking groove is integrated into the rotor or seal housing, and the locking bead is formed as part of the labyrinth seal assembly, combining the sealing and axial retention functions into a unified structure rather than adding separate independent components.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4013971B1Labyrinth seal with interlocking rotor and seal case insert
Publication Date: 2024.04.03 AMSTED RAIL CO INC
  • EP4013971B1 patent drawingFigure 1~2B
  • EP4013971B1 patent drawingFigure 3~7
  • EP4013971B1 patent drawingFigure 8

AI summary

A labyrinth seal includes a seal case with an inner-diameter leg encircling a rotation axis, and an insert fixed in the seal case and encircling the rotation axis. The labyrinth seal also includes a slinger encircling the rotation axis and wrapping around the inner-diameter leg to cooperate with the seal case to form a first part of a labyrinth path. The slinger rotates relative to the seal case. The labyrinth seal also includes a rotor that encircles the rotation axis, cooperates with the insert to form a second part of the labyrinth path, and interlocks with the insert to limit axial movement of the rotor when the rotor rotates relative to the insert. The labyrinth seal may be combined with a bearing cone, a bearing cup, and a plurality of rollers to form a roller bearing assembly.