Friction Damper Cylindrical Guide for Railway Wheelset

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Solution Overview

Problem

Existing railway car wheelset suspension systems face challenges in maintaining consistent kinetic forces and controlling uncontrolled movements, particularly due to the formation of ice or rime on guide and damper surfaces, which can lead to unpredictable friction changes and unstable travel.

Innovation Solution

The system incorporates helical springs with a cylindrical guide surface and a friction damper featuring planar, slanting surfaces that prevent lateral sliding and maintain even surface pressures, allowing for adjustable damping and improved control over the wheelset's movement, even in changing weather conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional guide surfaces are used in wheelset suspension, then the structure is simple, but ice or rime formation causes unpredictable friction changes and unstable travel

Engineering Contradiction:
Improvetravel stabilityVSAvoidice/rime formation on surfaces
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs a cylindrical guide surface with a specific radius of curvature (R = 50-150 mm) that guides the slider movement. This curved surface prevents moisture accumulation and ice/rime formation by ensuring continuous contact and pressure distribution, eliminating the flat surface problems that lead to unstable friction characteristics during cold weather operation.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention changes the geometric parameters of the guide surface from flat to cylindrical with specific radius constraints. This parameter change modifies the friction characteristics and pressure distribution, ensuring reliable travel stability by preventing ice/rime formation through continuous surface contact and pressure application during slider movement.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If curved guide surfaces are used to prevent ice formation, then travel stability improves, but the device complexity increases

Engineering Contradiction:
Improvetravel stabilityVSAvoidguide surface geometry
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cylindrical guide surface is integrated into the slider component itself, combining the guiding function with the moving part. This integration approach maintains travel stability through curved surface geometry while minimizing additional complexity by making the guide surface an inherent part of the slider rather than a separate component.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Ease of manufacture

If friction dampers with planar surfaces are used, then manufacturing is easier, but lateral sliding occurs and surface pressures become uneven

Engineering Contradiction:
Improvefriction surface fabricationVSAvoidsurface pressure distribution
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The cylindrical guide surface naturally distributes the load around its circumference, creating even pressure distribution across the friction surfaces. The curved geometry ensures that the slider maintains consistent contact with the guide surface throughout its movement, preventing lateral sliding and ensuring uniform pressure application without requiring complex manufacturing processes.

Inventive Principle:
Principle #14Spheroidality (Curvature)

4Reliability

If traditional dampers are used, then the structure is simple, but damping response cannot be forecast reliably under varying weather conditions

Engineering Contradiction:
Improvedamping response predictabilityVSAvoidfriction damper structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The friction damper incorporates a cylindrical guide surface with specifically controlled radius (R = 50-150 mm) and defined friction surface geometry (planar slanting surfaces at specific angles). These controlled geometric parameters ensure consistent friction characteristics and predictable damping response across varying operating conditions, including temperature and moisture variations, making the damping behavior forecastable despite environmental changes.

Inventive Principle:
Principle #35Parameter changes

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 prevents the formation of rime or ice between friction surfaces, ensuring stable travel and allowing for higher speeds, while adjustable friction surfaces enable controlled damping and reduced wear, maintaining consistent friction forces and surface pressures.

Implementation Method 1

a friction damper, the damping response of which can be better forecast than previously, irrespective of the running situation and conditions

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

helical springs fitted to the ends of the axle on both sides of the axle's axle box, in order to support the frame of the railway car

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3045373B1Friction damper supported by a joint
Publication Date: 2020.03.04 VR YHTYMAE
  • EP3045373B1 patent drawingFigure 1
  • EP3045373B1 patent drawingFigure 2

AI summary

Friction damper supported by a joint in the suspension of a wheelset of a railway car, comprising an axle (1), together with wheels (12), bearings (13), and axle boxes (2), there are helical springs (3) fitted to the ends of the axle (1) at least on both sides of the axle box (2) of the axle (1), in order to carry the railway car or to attach the bogie of the railway car to the frame of the bogie (4). At the side of the upper end of each helical spring (3) there is a slider (6) arranged to be moveably attached to the axle box (2) of the axle (1), in which there is at least one curved guide surface (7), which guide surface (7) has at least one radius of curvature parallel to the axle of the wheel pair around the axle. At the upper end of the helical springs (3), a friction damper is fitted, which comprises a counter surface (8) supported on the curved guide surface (7) of the axle box's (2) slider (6), the shape of which corresponds to the shape of the curved guide surface (7), a spring plate (9), which contains a head cap (17) for supporting the upper end of the helical spring (3), and at least one planar slanting friction surface (10) to be supported on a planar slanting counter surface (11) in the frame (4) of the bogie/car, which is correspondingly arranged to correspond to the slanting friction surface (10) of the friction damper.