Insulated Brake Lining Retainer for Railway Stray Currents

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Solution Overview

Problem

Stray currents in electrically powered rail vehicles, caused by electrical return currents during braking, disrupt electronic devices and pose safety risks, particularly in high-speed trains with light metal bodies and conductive brake pads, and existing insulation methods are costly and prone to heat degradation.

Innovation Solution

The introduction of electrical insulation between the brake lever and brake pad holder, using lightweight materials like polymer or ceramic bushings, maintains insulation even with wear and reduces heat exposure, allowing for cost-effective and durable insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrical insulation is applied to the brake caliper to prevent stray currents, then stray current propagation is prevented, but the cost increases and the insulation is exposed to high mechanical loads due to the large mass of the brake caliper

Engineering Contradiction:
Improveprevention of stray current propagationVSAvoidcost of insulation implementation
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts the electrical insulation function from the brake caliper and relocates it to the brake pad holder. This separation allows the insulation to be applied only where necessary (at the articulated connection point) rather than on the entire heavy brake caliper assembly, reducing material costs and simplifying implementation while maintaining the stray current prevention function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the braking system into functionally independent components with respect to electrical insulation. The brake pad holder is electrically insulated from the brake lever at the articulated connection, creating distinct electrical zones. This segmentation allows insulation to be applied locally at the connection point rather than throughout the entire brake caliper assembly.

Inventive Principle:
Principle #1Segmentation

2Reliability

If adhesive connection is used to electrically insulate the brake pad from the brake pad holder, then current path isolation is achieved, but the adhesive connection becomes complex due to high temperature load requirements

Engineering Contradiction:
Improveisolation of current pathVSAvoidcomplexity of adhesive connection
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary element - the articulated connection between the brake lever and brake pad holder - that provides electrical insulation without requiring high-temperature adhesive bonds. The insulated articulated connection acts as a mediator that maintains both mechanical connection for braking function and electrical isolation, simplifying the overall connection design compared to direct adhesive bonding of high-temperature materials.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Weight of moving object

If the brake caliper is made of light metal for high-speed trains, then weight is reduced, but electrical conductivity increases making the vehicle more susceptible to stray current effects

Engineering Contradiction:
Improveweight of brake caliperVSAvoidsusceptibility to stray currents
Core Design Contradiction:
Weight of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the electrical insulation requirement from the light metal brake caliper by relocating the insulation to the brake pad holder and articulated connection. This allows the brake caliper to maintain its lightweight aluminum construction without needing electrical insulation, while the insulated articulated connection prevents stray current propagation from the conductive brake pad into the light metal caliper and bogie.

Inventive Principle:
Principle #2Taking out (Extraction)

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

Effectively prevents the propagation of stray currents, reducing the risk of electronic disruptions and allowing for easy maintenance and conversion of disc brakes without requiring extensive safety testing.

Implementation Method 1

electrical insulation is formed between the brake lever and the brake pad holder

Methodology Applied
Scientific EffectElectrical insulation: Electrical Resistance

Data Source

PatentEP2337965B1Disk brake for a railway vehicle having an electrically insulated brake lining retainer
Publication Date: 2012.12.26 SIEMENS AG OESTERR
  • EP2337965B1 patent drawingFigure 1
  • EP2337965B1 patent drawingFigure 2~3
  • EP2337965B1 patent drawingFigure 4

AI summary

The invention relates to a disk brake for a railway vehicle, comprising: - a disk brake (5), - a brake caliper (9) encompassing the brake disk (5), said caliper pressing a brake lining (3) disposed on a brake lining retainer (4) against the brake disk (5) in case of actuation by means of a brake lever (11), wherein the brake lever (11) and the brake lining retainer (4) are connected to each other by means of a hinged connection (7), wherein – the brake lever (11) and the brake lining retainer (4) are configured in a manner such that the same are electrically insulated from each other.