Rail Spring Element Cover Layer to Prevent Fire-Retardant Wear

Solution Overview

Problem

Spring elements in the rail vehicle sector face challenges in meeting fire-protection requirements due to the poor fire behavior of damping bodies with high natural rubber content and the rapid wear of fire-retardant overlayers, which impair mechanical properties and lead to premature replacement.

Innovation Solution

A spring element with a fire-retardant overlayer featuring a compensation zone that prevents folding under stress, achieved through an interruption or thinner design, and crosslinking with the damping body to enhance mechanical strength and fire-protection, using materials like chloroprene rubber with flame retardants and acid-scavengers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If damping bodies with high natural rubber content are used to achieve good mechanical properties and vibration damping, then mechanical properties and damping performance are improved, but fire-protection behavior deteriorates

Engineering Contradiction:

Improvemechanical propertiesVSAvoidfire behavior

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The spring element is divided into two functional parts: a damping body made of natural rubber for mechanical performance and vibration damping, and a fire-retardant overlayer for fire protection. This segmentation allows each part to optimize its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The spring element uses a composite structure combining natural rubber damping body with a fire-retardant overlayer made of fire-resistant materials. This composite approach enables the system to simultaneously achieve good mechanical properties from the rubber and fire protection from the overlayer.

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If fire-retardant additives are incorporated into damping bodies to improve fire behavior, then fire-protection behavior is improved, but mechanical properties deteriorate

Engineering Contradiction:

Improvefire behaviorVSAvoidmechanical properties

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The spring element is divided into two functional parts: a damping body made of natural rubber for mechanical performance and vibration damping, and a fire-retardant overlayer for fire protection. This segmentation allows each part to optimize its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

3Object-affected harmful factors

If a fire-retardant overlayer is applied to protect damping body from fire, then fire-protection behavior is improved, but mechanical properties of overlayer deteriorate causing rapid wear

Engineering Contradiction:

Improvefire behaviorVSAvoidusage lifetime

Core Design Contradiction:

Object-affected harmful factorsVSDuration of action of stationary object

Solution Approach 1:

The overlayer is designed with different local properties: a compensation zone with specific geometric configuration that is less elastic and more wear-resistant, and other regions that provide fire protection. This local differentiation allows the overlayer to withstand mechanical loads in critical areas while maintaining fire-protection functionality elsewhere.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The compensation zone in the overlayer acts as a buffer that anticipates and absorbs mechanical stresses before they can cause damage to the less elastic fire-retardant material. This pre-positioned cushioning structure prevents excessive mechanical loading and extends the service life of the overlayer.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

4Object-affected harmful factors

If overlayer is made less elastic to improve fire-protection, then fire behavior is improved, but folding occurs during compression causing rapid wear

Engineering Contradiction:

Improvefire behaviorVSAvoidmechanical durability

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The overlayer is designed with different local properties: a compensation zone with specific geometric configuration that is less elastic and more wear-resistant, and other regions that provide fire protection. This local differentiation allows the overlayer to withstand mechanical loads in critical areas while maintaining fire-protection functionality elsewhere.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The compensation zone in the overlayer acts as a buffer that anticipates and absorbs mechanical stresses before they can cause damage to the less elastic fire-retardant material. This pre-positioned cushioning structure prevents excessive mechanical loading and extends the service life of the overlayer.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 allows for the use of damping bodies with good mechanical properties while ensuring compliance with fire-protection standards, extending the lifespan of spring elements by preventing excessive wear and maintaining fire-protection effectiveness under high loads.

Implementation Method 1

the at least one compensation zone (4) is configured in such a manner that folding of the overlayer (3) is prevented in the stressed condition of the spring element (1), in particular in a maximal stressing condition of the spring element (1)

Methodology Applied

Scientific EffectBuffer zone mechanism:

Implementation Method 2

the overlayer (3) and the damping body (2) are crosslinked to one another

Methodology Applied

Scientific EffectCrosslinking:

Implementation Method 3

using materials like chloroprene rubber with flame retardants and acid-scavengers

Methodology Applied

Scientific EffectFlame retardancy:

Implementation Method 4

using materials like chloroprene rubber with flame retardants and acid-scavengers

Methodology Applied

Scientific EffectAcid-scavenging:

Data Source

PatentUS12055192B2Spring element and fire-resistant cover layer

Publication Date: 2024.08.06 GMT GUMMI METALL TECHNIK GMBH

AI summary

The invention relates to a spring element for vibration damping and/or suspension of a rail vehicle, comprising at least one elastic damping body and at least one fire-resistant cover layer arranged on the damping body, the cover layer having at least one compensation zone, wherein the compensation zone is compressed in the loaded state of the spring element such that wrinkling of the cover layer is prevented, wherein the cover layer and the damping body are inseparably connected to form a composite element. The invention further relates to a cover layer and the use of a spring element or a cover layer.