Rail Bogie Suspension Stiffness Control for Bearing Wear Reduction

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Solution Overview

Problem

Existing secondary suspension bogies in rail vehicles suffer from serious wear of axle box bearings due to inappropriate selection of longitudinal stiffness and combined structural elements, leading to reduced dynamics performance and service life.

Innovation Solution

Adjust the longitudinal, axial, torsional, and conical stiffness of the rotating arm bush in the primary suspension system, modify the vertical stopper and fulcrum ball hinge in the secondary suspension system, and control the nonlinear stiffness of the traction ball hinge to reduce transverse loads and prevent axial movements, thereby improving the overall bogie performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the longitudinal stiffness of the rotating arm bush is increased to improve axle box positioning stability, then the axle box positioning stability is improved, but the transverse load on the bearing increases causing serious wear

Engineering Contradiction:
Improveaxle box positioning stabilityVSAvoidbearing wear
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by adjusting the longitudinal stiffness parameter of the rotating arm bush to an optimal range (11-13 KN/mm) rather than maximizing it. This controlled parameter adjustment achieves sufficient positioning stability while preventing excessive transverse loads that cause bearing wear, resolving the contradiction between stability and wear prevention.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The rotating arm bush is constructed as a composite structure combining rubber elastomer with metal sheathes. This composite material approach allows the rubber to provide flexible positioning while the metal sheathes reinforce the structure, enabling the system to achieve both stable axle box positioning and reduced bearing wear through material synergism.

Inventive Principle:
Principle #40Composite materials

2Force

If the vertical stiffness of the primary suspension is increased to improve load transmission, then the load transmission capability is improved, but the steel spring cracks due to excessive stress

Engineering Contradiction:
Improveload transmission capabilityVSAvoidsteel spring strength
Core Design Contradiction:
ForceVSStrength

Solution Approach 1:

The patent changes the vertical stiffness parameter of the primary suspension by adjusting the rubber elastomer properties and pre-compression force. This parameter adjustment optimizes the balance between load transmission capability and steel spring stress, preventing spring cracks while maintaining sufficient vertical stiffness for effective load transmission.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The rubber elastomer acts as an intermediary element between the steel spring and the axle box. It absorbs and distributes stresses, protecting the steel spring from excessive loads while still transmitting vertical forces effectively. This intermediary function resolves the contradiction between load transmission and spring strength.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the torsional stiffness of the rotating arm bush is increased to improve curve negotiation performance, then the curve negotiation performance is improved, but the conical stiffness increases causing excessive transverse load on the bearing

Engineering Contradiction:
Improvecurve negotiation performanceVSAvoidtransverse load on bearing
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent independently adjusts the torsional stiffness parameter to achieve optimal curve negotiation performance while controlling the conical stiffness parameter to prevent excessive transverse loads. By changing these parameters to specific ranges, the system achieves good curve handling without overloading the bearing, resolving the contradiction between adaptability and harmful loads.

Inventive Principle:
Principle #35Parameter changes

4Stability of the object's composition

If the axial stiffness of the fulcrum ball hinge is increased to prevent antiroll torsion bar axial movement, then the antiroll stability is improved, but the installation precision requirements increase

Engineering Contradiction:
Improveantiroll stabilityVSAvoidinstallation precision
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent adjusts the axial stiffness parameter of the fulcrum ball hinge to an optimal range that provides sufficient antiroll stability while avoiding excessive sensitivity to installation variations. This parameter optimization allows the system to maintain antiroll performance with relaxed installation precision requirements, resolving the contradiction between stability and manufacturing precision.

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

The adjusted structures effectively reduce axle box bearing wear, enhance vehicle stability, and prevent derailment by optimizing the stiffness ratios and preventing structural deformation, thus improving the overall performance and service life of the bogie.

Implementation Method 1

adjusting the rubber layer thickness of the rotating arm bush, the angle of a rubber layer bevel, the pre-compression amount of the rubber layer and the structural dimensions of metallic sheathes

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

structural dimensions of metallic sheathes

Methodology Applied
Scientific EffectMechanical Strength:

Implementation Method 3

pre-compression amount of the rubber layer

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP3369640B1A bogie suspension system
Publication Date: 2026.03.11 ZHUZHOU TIMES NEW MATERIAL TECHNOLOGY CO LTD
  • EP3369640B1 patent drawingFigure 1~2
  • EP3369640B1 patent drawingFigure 3~4
  • EP3369640B1 patent drawingFigure 5~6

AI summary

Disclosed are a method for improving overall performance of a rail vehicle bogie and a suspension damping system. The system rigidity of a torque arm node is adjusted by changing and adjusting torque arm node parameters so as to lower the longitudinal rigidity and the deflection rigidity of the torque arm node; meanwhile the axial rigidity is increased, such that a reduction in the torsional rigidity of the torque arm node is avoided. The structure of a vertical stop is changed to lower the vertical rigidity of a primary suspension. The structure of a supporting ball joint of an anti-side-roll torsion bar is changed to prevent the axial movement of the anti-side-roll torsion bar. The structure of a traction ball joint of a traction rod system component is adjusted to control the non-linear rigidity of the traction ball joint such that the non-linear rigidity of the traction ball joint has a smooth transition. The longitudinal rigidity, axial rigidity, torsional rigidity and deflection rigidity of the entire bogie are adjusted by changing the torque arm node and the vertical stop of the primary suspension system, changing the structure of the supporting ball joint of the anti-side-roll torsion bar of a secondary suspension system and changing the structure of the traction ball joint, such that the overall performance of the bogie is further improved.