Air Spring Bellows Folded Reinforcement Against Twist-Induced Leakage

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Solution Overview

Problem

Air suspension bellows in rail vehicles face premature wear and leakage due to strong lateral and twisting movements, which cause stress peaks and detachment of fabric layers from the bellows wall, leading to potential complete failure.

Innovation Solution

The reinforcement fabric is folded over the entire bellows wall, including the bead cores, with the free ends connected to create a self-contained, wear-resistant structure that can absorb multi-dimensional loads without detachment, eliminating the need for additional reinforcement measures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the free ends of fabric layers are looped around cores by hand and vulcanized to the bellows wall, then the air spring can be manufactured with embedded reinforcing elements, but the free ends detach during use under lateral and torsional movements, leading to wear and leakage

Engineering Contradiction:
Improvemanual looping and vulcanization processVSAvoidfabric layer attachment durability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The fabric layers are segmented into multiple layers with different orientations. Each layer is folded back onto itself to create separate attachment zones at the open ends, allowing each layer to be independently secured to the core without interfering with others, thus preventing detachment while maintaining manufacturability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fabric layers are folded back onto themselves in a direction perpendicular to their original extension, creating a multi-layered attachment structure at the open ends. This dimensional transformation allows the free ends to be securely attached to the core in a different spatial configuration, preventing detachment under lateral and torsional movements

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

2Reliability

If additional abrasion protection is applied to the bellows wall in the steel belt area, then the bellows is protected from abrasion damage, but the manufacturing process becomes complex

Engineering Contradiction:
Improveabrasion protectionVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The fabric layers themselves serve as both structural reinforcement and abrasion protection. By folding the fabric layers back onto themselves and attaching them to the core, the same material provides both functions, eliminating the need for separate abrasion protection layers and simplifying the manufacturing process

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

This design enhances the durability and reliability of air suspension systems by preventing fabric layer detachment and leakage, reducing manufacturing costs and maintaining suspension comfort while withstanding harsh rail vehicle movements.

Implementation Method 1

An air spring bellows (2) consists of an elastomer matrix with an outer elastomer layer and an inner elastomer layer, which form the outer and inner surfaces of the bellows wall (13), respectively

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

In the subsequent vulcanization process of the blank, the ends of the fabric layers are vulcanized flush with the bellows wall by the elastomer layers

Methodology Applied
Scientific EffectVulcanization:

Implementation Method 3

the air spring bellows (2) defines a working chamber (5) filled with compressed air

Methodology Applied
Scientific EffectGas pressure: Pressure Increase

Data Source

PatentEP3779233B1Air spring and method for manufacturing such an air spring
Publication Date: 2022.06.29 CONTITECH LUFTEDERSYSTEME GMBH
  • EP3779233B1 patent drawingFigure 1
  • EP3779233B1 patent drawingFigure 2

AI summary

The invention relates to an air spring bellows (2) which can be sealedly attached with its two open ends to connecting parts (3, 4) of two spaced-apart components, and which, in the assembled state of the air spring, at least partially delimits a working chamber (5) filled with compressed air, wherein the two ends of the air spring bellows are designed as bulges (6, 10) in which an annular core (7, 11) is arranged in each, and in which the cores are connected to a fabric-shaped reinforcing element (14) embedded in an elastic bellows material. To improve the operational reliability and load-bearing capacity of the air spring bellows (2), it is provided that the reinforcement element is folded over itself over the entire bellows wall (13), whereby the cores (7, 11) in the ridges (6, 10) are completely enclosed by the reinforcement element (14), and that the two free ends (17a, 17b) of the reinforcement element are brought together and connected to each other.In a process for manufacturing such an air spring bellows (2), the reinforcing element (14) is first folded over itself in a bellows blank over the entire bellows wall (13), whereby the cores are completely enclosed and the free ends (17a, 17b) of the reinforcing element are joined and connected at a seam (18), and then the bellows blank is vulcanized.