Rail Vehicle Bogie with Elastomeric Coupling for Spring Deflection

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Solution Overview

Problem

Traditional bogies for rail vehicles experience harsh thrust movements due to relative motion between frame parts, leading to high flexibility requirements in primary suspensions and uneven wheel load distribution, which can cause collisions and increased spring deflection.

Innovation Solution

A bogie design with two frame parts connected by a flexible elastomeric element and cranked cross beams, allowing for reduced spring deflection and improved torsional and axial stiffness, combined with anti-roll stabilizers and secondary springs for balanced wheel load distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If traditional bogies use a one-piece frame with high flexibility primary suspensions to counter stress from uneven railways, then the bogie can absorb track irregularities, but the primary spring deflection and rebound increases leading to potential collisions and harsh thrust movements

Engineering Contradiction:
Improvebogie stabilityVSAvoidspring deflection and collision risk
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The bogie frame is divided into two separate frame parts (first frame part and second frame part) that can move relative to each other. This segmentation allows the frame to absorb track irregularities through controlled relative movement rather than relying solely on flexible primary suspensions, thereby reducing spring deflection and collision risk.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the stiffness parameters of the connection between frame parts by using an elastomeric element with specific radial and axial stiffness characteristics. This allows the frame to provide sufficient support while enabling controlled relative movement to reduce thrust movements and spring deflection.

Inventive Principle:
Principle #35Parameter changes

2Strength

If bogies comprise two frame parts to allow for a stiffer primary suspension, then the primary suspension stiffness is improved, but the thrust of movements between frame parts is translated harshly

Engineering Contradiction:
Improveprimary suspension stiffnessVSAvoidharsh thrust movements
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

An elastomeric element is introduced as an intermediary component between the two frame parts. This element provides a flexible connection that allows relative movement while softening the thrust forces through its elastomeric properties, preventing harsh force transmission between frame parts.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The elastomeric element acts as a flexible connection component between frame parts, allowing controlled relative movement while absorbing and softening thrust forces. The elastomeric material provides both structural support and damping characteristics to reduce harsh movements.

Inventive Principle:
Principle #30Flexible shells and thin films

3Shape

If the pins are positioned at the ends of the longitudinal beams, then the cross beams can be straight, but the tilt of the pins and cardanic deformations increase

Engineering Contradiction:
Improvecross beam straightnessVSAvoidpin alignment stability
Core Design Contradiction:
ShapeVSStability of the object's composition

Solution Approach 1:

The cross beams are designed with cranked ends instead of straight ends, creating an asymmetric geometry that compensates for pin tilt and cardanic deformations. The cranked configuration allows the pin to maintain proper alignment despite the relative movement between frame parts.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The cranked configuration of the cross beam ends introduces a curved geometric element that accommodates the angular deviations and tilts of the pins during relative frame part movement, reducing cardanic deformations while maintaining pin alignment stability.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 solution reduces spring deflection, prevents collisions, and ensures equal wheel load distribution, enhancing the running characteristics and flexibility of the rail vehicle.

Implementation Method 1

The flexible connection of the frame parts soften the thrust of the movements due to the twisting of the tracks

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a rubber bushing (45), in particular a flange bushing, which rubber bushing is attached to the pin (44a) and which absorbs torsional and cardanic movements

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Data Source

PatentEP3992053B1Bogie for a rail vehicle and rail vehicle with a bogie
Publication Date: 2025.07.02 STADLER RAIL
  • EP3992053B1 patent drawingFigure 1
  • EP3992053B1 patent drawingFigure 2~3
  • EP3992053B1 patent drawingFigure 4

AI summary

The invention relates to a bogie (10) for a rail vehicle, comprising a bogie frame (11) and at least four wheels, which are arranged at the bogie frame (11). The bogie frame (11) comprises a first and a second frame part (1,2), each frame part (1,2) comprising a longitudinal beam (3a, 3b) and a cross beam (4a,4b). Each cross beam (4a, 4b) is fixedly attached at the first end (40a) to the respective longitudinal beam (3a,3b). Each cross beam (4a,4b) comprises a pin (44a,44b) at the second end (40b). The longitudinal beam (3a) of the first frame part (1) comprises a receptacle (51a) for the pin (44b) of the second frame part (2) and the longitudinal beam (3b) of the second frame part (2) comprises a receptacle (51b) for the pin (44a) of the first frame part (1). An at least partially elastomeric element (45), in particular an elastomeric flange bushing, is fixed to each the cross beam (4a, 4b) respectively, in particular to the pin (44a, 44b).