Asymmetrical Bogie Brake Disc Layout for Tramway Weight Reduction

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Solution Overview

Problem

Existing railway vehicle bogies face challenges in achieving optimal braking performance while maintaining a reasonable size and weight, especially when incorporating an automatic piloting device with a speed sensor, as symmetrical brake disc distributions either compromise braking or increase mass and cost.

Innovation Solution

A bogie with an asymmetrical distribution of three brake discs, where one wheel is without a brake disc, allowing for the installation of a speed sensor and maintaining good braking performance, reducing bulk and weight compared to traditional configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If four brake discs are installed on the bogie to improve braking performance, then braking performance is improved, but the bogie size and mass increase

Engineering Contradiction:
Improvebraking performanceVSAvoidbogie mass
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent applies asymmetry by installing brake discs on only three wheels instead of four, creating an asymmetric brake disc distribution. This resolves the contradiction by maintaining sufficient braking performance through strategic placement while reducing the overall number of brake discs, thereby decreasing bogie mass and size.

Inventive Principle:
Principle #4Asymmetry

2Ease of operation

If only two brake discs are installed to accommodate a speed sensor on an unbraked wheel, then the speed sensor can be installed, but braking performance is reduced

Engineering Contradiction:
Improvespeed sensor installationVSAvoidbraking performance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent uses asymmetric distribution with three brake discs placed on three different wheels, leaving one wheel unbraked for speed sensor installation. This configuration improves upon the symmetric two-disc approach by adding a third brake disc to enhance braking performance while still preserving one unbraked wheel for sensor accommodation.

Inventive Principle:
Principle #4Asymmetry

3Reliability

If four brake discs are installed, then braking performance is sufficient, but the lifecycle cost increases

Engineering Contradiction:
Improvebraking performanceVSAvoidlifecycle cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts one brake disc from the traditional four-disc configuration, reducing the total number to three. This extraction maintains adequate braking performance through optimized placement while directly reducing manufacturing costs, maintenance requirements, and overall lifecycle costs associated with fewer brake components.

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

The asymmetrical brake disc configuration enhances braking performance, reduces the bogie's size and weight, and enables reliable speed sensor installation for automatic piloting without compromising braking efficiency.

Implementation Method 1

braking means comprising brake discs, each brake disc being associated with a respective wheel

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3299659B1An optimized bogie for a railway vehicle, in particular a tramway
Publication Date: 2019.07.03 ALSTOM TRANSPORT TECH SAS
  • EP3299659B1 patent drawingFigure 1

AI summary

The bogie (10) comprises four wheels (12A, 12B, 12C, 12D) and braking means (18) comprising brake discs (20A, 20B, 20C), each brake disc (20A, 20B, 20C) being associated with a respective wheel. The braking means (18) comprise only three brake discs (20A, 20B, 20C), one of the wheels (12D) being without a brake disc.