Compliant Labyrinth Seal for Rotating Machinery

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Solution Overview

Problem

Labyrinth seals in hydromotive machines suffer from leakage and wear due to required axial and radial clearances that allow for dynamic shaft excursions, leading to efficiency losses and seal wear from abrasive contaminants.

Innovation Solution

A labyrinth seal configuration with radially compliant stationary elements that temporarily adjust to shaft excursions, allowing tighter radial clearances and incorporating a mount with a rigid layer sandwiched between compliant layers to manage abrasive particles and reduce wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If larger radial clearance is provided to allow for dynamic shaft excursions, then shaft position stability is improved, but leakage increases and hydraulic efficiency decreases

Engineering Contradiction:

Improveshaft position stabilityVSAvoidhydraulic efficiency

Core Design Contradiction:

Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The stationary labyrinth seal elements are made radially compliant rather than rigid, allowing them to dynamically adjust their position in response to shaft excursions. This compliance enables the seal to maintain tighter average clearances while still accommodating dynamic shaft movements, thereby reducing leakage and improving hydraulic efficiency without sacrificing shaft position stability

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The radial clearance parameter is changed from a fixed value to a variable parameter that can dynamically adjust based on operating conditions. The compliant stationary elements allow the clearance to vary radially while maintaining axial positioning, enabling optimization of leakage reduction while accommodating shaft excursions

Inventive Principle:

Principle #35Parameter changes

2Reliability

If larger axial clearance is provided to avoid interference and wear, then seal reliability is improved, but leakage increases

Engineering Contradiction:

Improveseal reliabilityVSAvoidleakage

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The seal structure is designed with different clearance characteristics in different directions: tight radial clearance to minimize leakage and larger axial clearance to prevent interference and wear. This anisotropic clearance design allows optimization for each specific function, reducing overall energy loss while maintaining reliability

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The compliant stationary elements dynamically respond to radial movements, allowing the seal to maintain optimal clearance characteristics during operation. This dynamic adaptation enables the seal to achieve both low leakage and high reliability without requiring uniformly large clearances

Inventive Principle:

Principle #15Dynamics

3Loss of energy

If tighter radial clearances are used to reduce leakage, then hydraulic efficiency is improved, but wear from abrasive contaminants increases

Engineering Contradiction:

Improvehydraulic efficiencyVSAvoidseal wear

Core Design Contradiction:

Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The compliant stationary elements act as a cushioning mechanism that absorbs and mitigates the impact of abrasive contaminants in the leakage flow. By providing a compliant surface rather than a rigid one, the wear caused by abrasive particles is significantly reduced, allowing tighter clearances to be used for improved hydraulic efficiency

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The labyrinth seal is constructed from composite materials with different properties: the rotating elements use wear-resistant materials to withstand abrasive contaminants, while the stationary elements use compliant materials that can deform to accommodate particles and reduce wear. This material composite approach enables tighter clearances with reduced wear risk

Inventive Principle:

Principle #40Composite materials

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 reduces leakage and wear, enhancing hydraulic efficiency and extending seal life by accommodating shaft dynamics and abrasive particles effectively.

Implementation Method 1

a mount (119) having a substantially rigid layer (120) sandwiched between substantially compliant layers (121)

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS20250207553A1Compliantly mounted labyrinth seal

Publication Date: 2025.06.26 OBERMEYER HENRY K

AI summary

A labyrinth seal for sealing between a rotating portion and a non-rotating portion of rotating machinery, the labyrinth seal having a first portion and a second portion. The first portion has a series of projections and recessions that are concentric about an axis of rotation of the rotating portion of the rotating machinery. The second portion has a series of projections and recessions that are concentric about the axis of rotation. The projections of the series of projections and recessions of the second portion are configured to mate with the recessions of the series of projections and recessions of the first portion. The projections of the series of projections and recessions of the first portion are configured to mate with the recessions of the series of projections and recessions of the second portion. The second portion includes a mount having a substantially rigid layer sandwiched between substantially compliant layers.