Meander Clamping Ring Bellows for Self-Centering Seals

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Solution Overview

Problem

The existing sealing bellows with embedded clamping rings have high manufacturing costs and efforts due to complex assembly and chemical pretreatment, which can lead to environmental pollution and are not self-centering, resulting in potential leakage issues.

Innovation Solution

A sealing bellows with a clamping ring formed as a circular, meander-shaped disc that is elastically variable in diameter, allowing for self-centering and even radial expansion to securely grip machine elements without chemical bonding, using metallic or polymeric materials for cost-effective and environmentally friendly production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a clamping ring is embedded in the edge region of the sealing bellows, then the sealing reliability is improved, but the manufacturing complexity and production costs increase significantly

Engineering Contradiction:
Improvesealing reliabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The clamping ring is extracted from the embedded configuration and replaced with an external clamp that acts on the sealing bellows from the outside. This eliminates the need for embedding the clamping ring into the edge region, thereby reducing manufacturing complexity while maintaining the sealing function through external clamping force.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of embedding the clamping ring inside the edge region (internal configuration), the solution inverts the approach by using an external clamp that surrounds and clamps the sealing bellows from the outside. This inversion simplifies manufacturing while achieving the same sealing reliability through external mechanical constraint.

Inventive Principle:
Principle #13The other way round (Inversion)

2Strength

If chemical pretreatment is applied to the clamping ring for embedding, then the bonding strength is improved, but environmental pollution increases and production costs rise

Engineering Contradiction:
Improvebonding strengthVSAvoidenvironmental pollution
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The chemical bonding system (adhesive pretreatment and vulcanization) is replaced with a purely mechanical clamping system. The external clamp exerts direct mechanical force on the sealing bellows to achieve the desired sealing effect, eliminating the need for chemical pretreatment and associated environmental pollution while maintaining sufficient bonding strength through mechanical constraint.

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

Solution Approach 2:

The solution replaces the expensive and environmentally harmful chemical pretreatment process with a simpler, more cost-effective mechanical clamping approach. The external clamp provides sufficient sealing force without requiring costly adhesives or complex chemical processing, thereby reducing both production costs and environmental impact.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Manufacturing precision

If a rigid clamping ring with fixed diameter is used, then the manufacturing precision is improved, but the adaptability to tolerance variations decreases

Engineering Contradiction:
Improveclamping ring diameter precisionVSAvoidadaptability to tolerance variations
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The rigid clamping ring with fixed diameter is replaced with a dynamic clamp that can adapt its configuration to match the actual dimensions of the sealing bellows. The clamp's flexible or adjustable design allows it to accommodate tolerance variations in the sealing bellows while maintaining precise clamping force, thereby improving adaptability without sacrificing manufacturing precision.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Instead of using a clamping ring with a fixed, precisely controlled diameter, the solution employs a clamp whose effective clamping parameters can vary to adapt to the actual dimensions of the sealing bellows. This parameter flexibility allows the clamp to accommodate tolerance variations while maintaining sufficient clamping precision for reliable sealing.

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If an open clamping ring with toothed geometry is used, then the ease of assembly is improved, but the device complexity increases due to the need for assembly tools and procedures

Engineering Contradiction:
Improveease of assemblyVSAvoidassembly tool complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The separate assembly tool and clamping ring are merged into a single integrated external clamp component. This unified design eliminates the need for separate assembly tools and complex toothed engagement procedures, thereby maintaining ease of assembly while reducing overall device complexity. The clamp is designed to be installed directly onto the sealing bellows without requiring additional tools.

Inventive Principle:
Principle #5Merging (Combining)

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 simplifies assembly, ensures automatic centering, and provides a long-lasting, tight seal with reduced risk of leakage and environmental impact, suitable for large series production.

Implementation Method 1

The clamping ring (4, 5) each consist of a metallic material... the clamping ring is formed as a circular, meander-shaped disc that is elastically variable in diameter, allowing for self-centering and even radial expansion

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3726076B1Sealing bellow
Publication Date: 2022.02.09 CARL FREUDENBERG KG
  • EP3726076B1 patent drawingFigure 1
  • EP3726076B1 patent drawingFigure 2
  • EP3726076B1 patent drawingFigure 3

AI summary

A sealing bellows comprising a sheath (1) made of a rubber-elastic material, which has an edge region (2, 3) on each end face, wherein a clamping ring (4, 5) for fastening the sealing bellows to a machine element is arranged in at least one of the edge regions (2, 3). The clamping ring (4, 5) is formed by an annular disk (6) which, viewed in the circumferential direction (7), has a meandering shape.