Rail Wheel Brake Disc Segmentation for Mass and Thermal Stability

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Solution Overview

Problem

Existing wheel brake discs for rail vehicles face challenges in balancing thermal stability and mass reduction, particularly in high-speed applications where energy absorption and friction performance are critical, and existing designs often compromise on mass and temperature management.

Innovation Solution

The wheel brake disc features an annular friction belt with reduced thickness, cooling ribs, and elastic screw receptacles, along with annular grooves on the friction surface to manage thermal expansion, allowing for efficient heat dissipation and reduced mass without compromising friction performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If the thickness of the friction belt is reduced, then the mass of the wheel brake disc is reduced, but the temperature management and friction performance may deteriorate

Engineering Contradiction:
Improvemass of wheel brake discVSAvoidfriction temperature
Core Design Contradiction:
Weight of moving objectVSTemperature

Solution Approach 1:

The brake disc is segmented into a thin friction belt and a thicker cooling body with cooling ribs. This segmentation allows the friction belt to be thin (reducing mass) while the cooling ribs provide thermal management, resolving the contradiction between low mass and temperature control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention moves from a uniform thickness design to a variable thickness design where the friction belt is thin but the overall disc includes thick cooling ribs extending in the radial direction. This dimensional change allows mass reduction in the friction area while maintaining thermal capacity through the cooling structure.

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

2Weight of moving object

If the thickness of the friction belt is reduced, then the mass is reduced, but the structural strength and deformation resistance may worsen

Engineering Contradiction:
Improvemass of wheel brake discVSAvoidstrength and deformation resistance
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The structure is divided into a thin friction belt for friction contact and a thicker support structure with cooling ribs for mechanical strength. This segmentation allows the friction belt to be thin (low mass) while the cooling ribs provide the necessary structural strength and deformation resistance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The brake disc employs a composite structure combining a thin friction belt material with a thicker cooling body material, optimizing both mass and strength properties through material and structural composition rather than uniform material selection.

Inventive Principle:
Principle #40Composite materials

3Temperature

If cooling ribs are added to the wheel brake disc, then heat dissipation is improved, but the mass and device complexity increase

Engineering Contradiction:
Improveheat dissipation capabilityVSAvoidmass of wheel brake disc
Core Design Contradiction:
TemperatureVSWeight of moving object

Solution Approach 1:

Cooling ribs are added only in specific locations where thermal management is needed, rather than uniformly throughout the entire disc. This localized approach improves heat dissipation while minimizing the mass increase and structural complexity.

Inventive Principle:
Principle #3Local quality

4Weight of moving object

If the friction belt thickness is reduced, then mass is reduced, but the permissible temperature gradient and thermal stability may deteriorate

Engineering Contradiction:
Improvemass of wheel brake discVSAvoidthermal stability
Core Design Contradiction:
Weight of moving objectVSStability of the object's composition

Solution Approach 1:

The thin friction belt is segmented or supported by cooling ribs that prevent excessive thermal gradients. The cooling ribs act as thermal anchors, allowing the thin friction belt to maintain thermal stability despite its reduced thickness and lower thermal mass.

Inventive Principle:
Principle #1Segmentation

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 maintains permissible friction temperatures and reduces mass, enhancing thermal stability and energy efficiency while minimizing dynamic screw forces and material accumulation, thus preventing permanent deformations.

Implementation Method 1

a multiplicity of cooling ribs which are formed on an assembly side facing away from a friction surface of the friction belt

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

The thickness of the friction belt is less than a third of the maximum thickness of the wheel brake disc

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

an annular friction belt, a multiplicity of cooling ribs which are formed on an assembly side facing away from a friction surface of the friction belt

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 4

a region of the screw receptacles of the wheel brake disk surrounding the bore is, according to an advantageous variant, designed to be elastic in a direction axial to the longitudinal axis of the screw neck

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3760891B1Rail wheel and wheel brake disc for a rail wheel of a railway vehicle
Publication Date: 2022.03.23 KNORR BREMSE SYST FUR SCHIENENFAHRZEUGE GMBH
  • EP3760891B1 patent drawingFigure 1
  • EP3760891B1 patent drawingFigure 2~3
  • EP3760891B1 patent drawingFigure 4~5

AI summary

A wheel brake disc (3) for a rail wheel of a rail vehicle has an annular friction belt, a plurality of cooling fins (32, 36) which are integrally formed on a mounting side facing away from a friction surface (311) of the friction belt, several screw receptacles (33) for receiving a nut or screw head of a screw for fastening the wheel brake disc (3) to a wheel web of a wheel body of the rail wheel, wherein the thickness (d1) of the friction belt (31) is less than one third of the maximum thickness of the wheel brake disc (3).