Hollow Cylindrical Rail Simulation System for Adhesion Analysis

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Solution Overview

Problem

Existing systems for simulating the contact between a railway vehicle wheel and rail struggle to maintain a stable contaminant layer due to centrifugal forces, limiting the simulation of rail contamination and adhesion analysis to specific types and speeds, and introducing unrealistic cleaning effects.

Innovation Solution

A system comprising a hollow cylindrical structure with a rail simulation surface and a wheel, where both are rotated independently by motors, and a contaminant control system ensures a stable contaminant layer on the inner surface, using sensors to measure adhesion and load forces, and a contaminant distribution system to maintain the layer, allowing for varied contaminants and speeds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a cylindrical roller is used to simulate a rail and the angular speed of the roller is increased, then the simulation speed increases, but the centrifugal force flings away the contaminant from the roller surface

Engineering Contradiction:
Improveangular speed of the rollerVSAvoidstability of the contaminant layer
Core Design Contradiction:
SpeedVSStability of the object's composition

Solution Approach 1:

The patent inverts the traditional roller configuration by using a hollow cylindrical structure with the rail simulation surface on the inner surface rather than the outer surface. This inversion changes the direction of centrifugal force acting on the contaminant, causing it to press against the rail simulation surface instead of being flung away, thereby maintaining contaminant stability at higher rotation speeds

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the geometric parameter of the roller configuration from a solid cylindrical roller with outer surface contact to a hollow cylindrical structure with inner surface contact. This parameter change fundamentally alters the centrifugal force direction and enables stable contaminant layer maintenance across a wider speed range

Inventive Principle:
Principle #35Parameter changes

2Speed

If the angular speed of the roller increases, then the simulation capabilities improve, but the cleaning effect between wheels becomes unrealistic

Engineering Contradiction:
Improveangular speed of the rollerVSAvoidrealism of contaminant simulation
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

By inverting the roller configuration to use inner surface contact, the patent eliminates the unrealistic cleaning effect that occurs in traditional outer surface rollers. The contaminant remains stably adhered to the inner surface even at high speeds, accurately simulating real rail contamination conditions without artificial cleaning between wheel passages

Inventive Principle:
Principle #13The other way round (Inversion)

3Quantity of substance

If contaminant injection systems are used on traditional rollers, then contaminant application is achieved, but the contaminant is flung away due to centrifugal force

Engineering Contradiction:
Improvecontaminant applicationVSAvoidcontaminant retention
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent applies contaminant to the inner surface of the hollow cylindrical structure, where centrifugal force during rotation presses the contaminant against the surface rather than flinging it away. This inversion of the application surface fundamentally resolves the contaminant retention problem while maintaining effective contaminant application

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent converts the harmful centrifugal force that flings contaminant away in traditional rollers into a beneficial force that presses contaminant against the inner surface of the hollow cylindrical structure. By inverting the configuration, the same centrifugal effect that causes problems in conventional systems becomes the mechanism for stable contaminant retention

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

Enables stable simulation of rail contamination and evaluation of its impact on adhesion, considering realistic cleaning effects, for any type of contaminant and speed, providing accurate adhesion coefficient calculations.

Implementation Method 1

the contaminant substance deposited on the roller by the injection system is flung away by the roller due to centrifugal force, Fcentr, proportional to the square of the angular speed of the roller and the radius of the roller

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

at least one wheel (9) having a second diameter (D2), smaller than said first diameter (D1), and including a rolling surface (11) placed in contact with said rail simulation surface (5)

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3601978B1A system and a method for simulating the contact between wheel and rail for detecting the adhesion value
Publication Date: 2021.01.20 FAIVELEY TRANSPORT ITAL SPA
  • EP3601978B1 patent drawingFigure 1
  • EP3601978B1 patent drawingFigure 2
  • EP3601978B1 patent drawingFigure 3

AI summary

A system is described for simulating the contact between wheel and rail (1), in particular of a rail vehicle, comprising: - at least one hollow cylindrical structure (3) having a first diameter (D1) and including a rail simulation surface (5) arranged integrally with an internal surface (7) of said hollow cylindrical structure (3); and - at least one wheel (9) having a second diameter (D2) smaller than the first diameter (D1) and including a rolling surface (11) adapted to be placed in contact with said rail simulation surface (5) of the hollow cylindrical structure (3).