7-Shaped Seal Ring With Dirt Lip for Contamination Blocking

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing sealing rings lack protection against contamination, which can reduce the service life and performance of the sealing lip, leading to potential damage and increased friction losses.

Innovation Solution

A 7-shaped sealing ring design featuring a dirt lip with a radially inner first boundary surface and a radially outer second boundary surface, where the first length is greater than the third length, and a second joint linking the sealing leg and dirt lip, allowing the dirt lip to follow the sealing leg's radial movements and prevent contamination from reaching the sealing lip.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sealing ring with sealing lip is used, then sealing function is achieved, but the sealing lip is exposed to contaminants that reduce service life

Engineering Contradiction:
Improveservice life of sealing lipVSAvoidcontaminant exposure
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A dirt lip is introduced as an intermediary element between the contaminants and the sealing lip. The dirt lip has a sealing edge that contacts the machine element and creates a barrier, preventing contaminants from reaching the sealing lip while allowing the sealing lip to maintain its sealing function

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sealing ring is segmented into functionally distinct parts: a sealing leg with sealing lip for sealing, and a dirt lip for contamination protection. This segmentation allows each part to be optimized for its specific function, with the dirt lip serving as a protective barrier

Inventive Principle:
Principle #1Segmentation

2Reliability

If sealing lip is made longer and more flexible, then sealing contact is improved, but friction losses increase

Engineering Contradiction:
Improvesealing contact consistencyVSAvoidfriction losses
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

Different parts of the sealing ring have different lengths and flexibility characteristics optimized for their specific functions. The sealing lip is longer and more flexible for consistent sealing contact, while the dirt lip is shorter and stiffer to minimize friction and prevent contamination

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If dirt lip sealing edge diameter is increased, then contamination protection is improved, but assembly precision requirements increase

Engineering Contradiction:
Improvecontaminant blocking capabilityVSAvoidassembly precision
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The dirt lip and sealing lip have different diameters, with the dirt lip having a larger sealing edge diameter than the sealing lip diameter. This asymmetric design allows the dirt lip to effectively block contaminants while the sealing lip maintains proper sealing contact, with each element optimized for its specific function

Inventive Principle:
Principle #4Asymmetry

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 design effectively protects the sealing lip from contamination, maintaining consistent performance and reducing friction losses, while allowing for flexible operation in various environments and applications with minimal assembly risks.

Implementation Method 1

the dirt lip is designed to prevent contaminants from the area surrounding the sealing ring from adversely penetrating to the sealing lip

Methodology Applied
Scientific EffectPhysical barrier: Physical Containment

Implementation Method 2

the sealing lip maintains a consistent radial preload on the sealing surface of the machine element throughout its service life

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

The clamping element is ring-shaped and, in cross-section, formed by a figure-eight-shaped spring

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP3872373B1Seal ring and its use
Publication Date: 2023.08.02 CARL FREUDENBERG KG
  • EP3872373B1 patent drawingFigure 1

AI summary

A sealing ring, which in cross-section is 7-shaped, comprising a first axial leg (1) and a sealing leg (2) with a sealing lip (3), wherein the sealing leg (2) is connected to a first end face (5) of the first axial leg (1) by means of a first joint (4). The sealing leg (2) has on its side axially facing the first end face (5) a dirt lip (6) with at least one sealing edge (7) and a radially inner first boundary surface (8) and a radially outer second boundary surface (9).