Labyrinth Seal Structure for Water Ingress and Debris Discharge

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Solution Overview

Problem

Existing sealing devices fail to effectively prevent water, including muddy or salt water, from entering sealed objects and do not efficiently discharge foreign matter when used in wet environments.

Innovation Solution

A sealing device with a first sealing member and a second sealing member, featuring a cylindrical part, an annular part, a radial lip, and a labyrinth lip that extends radially outward, creating a second clearance for the discharge of foreign matter, which covers the first clearance to prevent ingress and facilitates rapid discharge through a radial second clearance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional sealing device with a first clearance between the flange and cylindrical part is used, then the structure is simple and easy to manufacture, but water and foreign matter can easily enter the sealed object

Engineering Contradiction:
Improveprotection against water ingressVSAvoidsealing structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sealing device combines a rigid cylindrical part with a flexible lip made of elastic material. This composite structure allows the lip to deform and seal effectively against the flange, preventing water ingress while maintaining structural integrity. The elastic material compensates for manufacturing tolerances and surface irregularities, enhancing sealing reliability without requiring overly complex machining.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention extends the sealing solution into the radial dimension by adding a lip that protrudes from the cylindrical part toward the flange. This creates a three-dimensional sealing path rather than relying solely on a planar clearance, effectively blocking water ingress routes while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If the first clearance is left open for simple structure, then manufacturing is easier, but foreign matter cannot be discharged efficiently

Engineering Contradiction:
Improveforeign matter discharge efficiencyVSAvoidsealing structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The sealing structure is divided into functional segments: the first clearance for initial foreign matter entry, the lip for sealing, and the second clearance for discharge. This segmentation allows each component to perform its specific function optimally - the first clearance accepts debris, the lip seals the main gap, and the second clearance provides an escape route, achieving efficient foreign matter management without excessive complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lip acts as an intermediary element between the first and second clearances. It selectively controls the flow path: allowing small particles to pass through while blocking larger foreign matter and water, then directing controlled discharge through the second clearance. This intermediary structure achieves sophisticated foreign matter management with a single, relatively simple component.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the lip extends far toward the flange to improve sealing, then water ingress is prevented, but the lip may contact the flange and cause wear or damage

Engineering Contradiction:
Improvesealing effectivenessVSAvoidlip durability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention optimizes the geometric parameters of the lip, specifically its length and curvature, to achieve the right balance. The lip extends sufficiently to contact or near-contact the flange for effective sealing, but its elastic material properties and precise dimensional control prevent excessive contact pressure that would cause wear. The parameter optimization allows the lip to deform elastically during operation, maintaining sealing contact while distributing wear evenly and preventing damage.

Inventive Principle:
Principle #35Parameter changes

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 sealing device provides superior protection against foreign matter ingress and rapid discharge of water, enhancing the sealing performance in wet environments by utilizing the labyrinth lip to cover the first clearance and ensure foreign matter is discharged through the second clearance.

Implementation Method 1

at least one lip made of an elastic material that extends toward the flange of the second sealing member

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a labyrinth lip extending from the flange radially outward and extending toward the atmosphere side more than the cylindrical part of the first sealing member, and a second clearance is provided between the labyrinth lip and the outer member

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3985271B1Sealing device
Publication Date: 2024.05.08 NOK CORP
  • EP3985271B1 patent drawingFigure 1
  • EP3985271B1 patent drawingFigure 2
  • EP3985271B1 patent drawingFigure 3

AI summary

A sealing device adapted to be disposed between an inner member and an outer member that rotate relative to each other includes a first sealing member including a cylindrical part adapted to be mounted to the outer member, and an annular part that extends radially inward from the cylindrical part; and a second sealing member including a sleeve adapted to be mounted to the inner member, and a flange. The first sealing member includes a lip that extends toward the flange of the second sealing member. An annular first clearance is provided between the flange and the cylindrical part of the first sealing member. The second sealing member includes a labyrinth lip extending from the flange radially outward and extending toward the atmosphere side more than the cylindrical part of the first sealing member, and a second clearance is provided between the labyrinth lip and the outer member. The second clearance is radially outside the first clearance and communicates with the first clearance.