Side Lip Sealing Structure for Lubricant Retention and Wear Control

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Solution Overview

Problem

Conventional sealing devices experience accelerated wear and noise due to lubricant depletion over time, which affects their performance and durability.

Innovation Solution

The sealing device incorporates a side lip with a plurality of annular grooves on its sliding surface, where the annular protrusions between grooves protrude most at the center, decreasing gradually, and are symmetrically shaped, allowing lubricant to be retained and moved evenly, preventing depletion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If lubricant is applied on the sliding surface of the side lip, then the side lip can prevent dust or mud water from entering the device, but the lubricant becomes depleted over time causing accelerated wear and noise

Engineering Contradiction:
Improvesealing performanceVSAvoidlubricant depletion
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The sliding surface of the side lip is segmented into multiple annular grooves that divide the lubricant retention area into separate sections. This segmentation allows lubricant to be distributed and retained in multiple locations simultaneously, preventing depletion at any single point while maintaining continuous sealing performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The annular grooves are pre-formed on the sliding surface to create lubricant retention areas before the sealing device begins operation. This preliminary structuring ensures that lubricant is immediately available at the contact surface from the start of operation, eliminating the need for external lubrication maintenance during operation.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If the side lip sliding surface is made planar for simple manufacturing, then manufacturing is easier, but lubricant cannot be retained and depletion occurs quickly

Engineering Contradiction:
Improvesliding surface fabricationVSAvoidlubricant retention
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

The sliding surface is segmented into multiple annular grooves that are easily formed using conventional machining processes. This segmentation creates lubricant retention areas without requiring complex manufacturing steps, as the grooves can be produced through simple radial or axial cutting operations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The annular grooves create a porous-like structure on the sliding surface that physically traps and retains lubricant. This structured surface allows the side lip to self-lubricate during operation, maintaining sealing performance without requiring external lubrication systems.

Inventive Principle:
Principle #31Porous materials

3Reliability

If asymmetric protrusions are provided on the side lip to improve sealing, then sealing performance improves, but imbalance in movement directions causes uneven lubricant distribution and depletion

Engineering Contradiction:
Improvesealing effectivenessVSAvoiduneven lubricant distribution
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The annular protrusions are designed with asymmetric cross-sectional shapes that optimize sealing effectiveness while maintaining symmetric radial distribution. The asymmetric profile provides enhanced sealing contact on one side while the symmetric radial arrangement ensures uniform lubricant distribution around the entire circumference, preventing localized depletion.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The annular protrusions provide localized sealing enhancement at specific radial positions while the overall symmetric arrangement ensures uniform lubricant distribution. This local quality approach allows optimized sealing at critical points without compromising overall lubricant retention and distribution.

Inventive Principle:
Principle #3Local quality

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 configuration effectively suppresses lubricant depletion, reduces wear on the side lip, prevents noise generation, and enhances the durability of the sealing device.

Implementation Method 1

the side lip is provided with a plurality of annular grooves on the sliding surface, so that the side lip can retain lubricant in the plurality of annular grooves

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP3974687B1Sealing device
Publication Date: 2025.02.19 NOK CORP
  • EP3974687B1 patent drawingFigure 1
  • EP3974687B1 patent drawingFigure 2
  • EP3974687B1 patent drawingFigure 3

AI summary

A sealing device capable of suppressing depletion of lubricant is provided. A sliding surface of a side lip 220 at a position away from a distal end of the side lip 220 is provided with a plurality of annular grooves 222 adjacent each other, each of all parts that form annular protrusions 223 between adjacent annular grooves 222 protrudes most at a center in a width direction thereof, with an amount of protrusion gradually decreasing with increasing separation from the center, and both sides of the center in the width direction are symmetric in shape. A tip portion of the sliding surface of the side lip 220 on the distal side of a region, which is provided with the plurality of annular grooves 222, is configured to make a planar contact with an end face of the annular member.