Railway Disc Brake Pad Spacer Design for Pressure Distribution

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Solution Overview

Problem

Existing disc brake pads for railway vehicles face premature damage of friction elements due to non-homogeneous pressure on the disc surface, which is exacerbated by circular spacers used for cooling ventilation, as they amplify pressure irregularities and compromise cooling efficiency.

Innovation Solution

The pad design incorporates spacers with a central locking hole and radially extending support arms that contact the support plates without being fixed, providing enhanced support and ventilation by maintaining a gap for cooling while distributing pressure more evenly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If circular spacers are used to ensure cooling ventilation, then cooling efficiency is improved, but friction elements suffer premature damage due to amplified non-homogeneous pressure

Engineering Contradiction:
Improvecooling ventilationVSAvoidfriction element durability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The spacer is segmented into a central portion and multiple radially extending support arms. This segmentation allows the spacer to perform multiple functions: the central portion with the locking hole provides cooling ventilation, while the distributed support arms provide structural support to multiple points on the support plate, reducing non-homogeneous pressure and preventing friction element damage.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the diameter of circular spacers is increased to improve support of friction elements, then friction element preservation is improved, but cooling ventilation effectiveness decreases

Engineering Contradiction:
Improvefriction element supportVSAvoidcooling ventilation
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The spacer design transitions from a two-dimensional circular shape to a three-dimensional structure with radially extending arms. This dimensional change allows the spacer to maintain a compact overall diameter (preserving cooling gaps) while extending support coverage to multiple radial positions, thereby improving friction element support without compromising ventilation.

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

3Temperature

If circular spacers are used for cooling, then ventilation gap is maintained, but non-homogeneous pressure on disc is amplified causing premature damage

Engineering Contradiction:
Improvecooling ventilationVSAvoidnon-homogeneous pressure
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The radially extending support arms act as intermediaries between the spacer and the support plate. These arms distribute the mechanical loads and pressure fluctuations across multiple contact points, mediating the transmission of non-homogeneous pressure from the disc to the friction elements, thereby reducing the amplifying effect that would otherwise lead to premature damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively supports friction elements, preventing premature damage and deformation while maintaining effective cooling ventilation, leading to improved braking efficiency and extended pad life.

Implementation Method 1

The presence of the circular spacers creates a gap between the support plates and the base plate, so as to encourage a cooling ventilation on the lower surface of the friction elements

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

Each one of the circular spacers has a central hole which, in the assembled pad, is engaged by the rivet assigned to blocking the support plate on the base plate

Methodology Applied
Scientific EffectMechanical Fastening: Mechanical Fastener

Implementation Method 3

there has to be a good transmission of the braking force from the pad to the disc

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3569887B1Pad for disc brakes for railway vehicles
Publication Date: 2020.12.23 COFREN SRL
  • EP3569887B1 patent drawingFigure 1~2
  • EP3569887B1 patent drawingFigure 3~4

AI summary

A pad (1) for disc brakes for railway vehicles comprising a base plate (2), a plurality of support plates (4) mounted on the base plate (2), a plurality of friction elements (3), each fixed on a respective support plate (4), and a plurality of spacers (6; 11), each mounted between the base plate (2) and a respective support plate (4). In each one of the spacers (6; 11) there is obtained a hole (8; 13) engaged by a respective rivet (5) designed to lock the support plate (4) on the base plate (2). Each one of the spacers (6; 11) comprises a central portion (7; 12) where the hole (8; 13) is made, and a plurality of support arms (9; 14) radially extending from the central portion (7; 12).