Rubber-Tired Light Rail Bogie With Bidirectional Return Spring

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Solution Overview

Problem

Rubber-tired light rail vehicles experience excessive rotational movement and vibration when traveling in curved or inclined sections due to unidirectional coil springs and lack of leftward-rightward shock absorption, leading to decreased riding comfort and stability.

Innovation Solution

A bogie design featuring a return spring with equal force compression and decompression, combined with a leftward-rightward shock absorber, to stabilize the vehicle body and frame, reducing rotational movement and lateral vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a unidirectional coil spring is used for rotation control between bogie and vehicle body, then the spring can exert force in one direction, but excessive rotational movement occurs and different spring forces are exerted bidirectionally

Engineering Contradiction:
Improvespring forceVSAvoidrotational stability
Core Design Contradiction:
ForceVSStability of the object's composition

Solution Approach 1:

The patent combines a compression spring and an extension spring into a single rotation control mechanism, allowing bidirectional force application. The compression spring handles one direction of rotation while the extension spring handles the opposite direction, ensuring consistent rotational control and preventing excessive yawing movement.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a dynamic adjustment mechanism that allows the spring forces to be equalized bidirectionally. By making the spring forces adjustable and equal in both compression and extension directions, the system achieves stable rotational control without excessive movement.

Inventive Principle:
Principle #15Dynamics

2Device complexity

If no leftward-rightward shock absorber is provided for the guiding wheel, then the structure remains simple, but vibration and shock between guiding rail and guiding wheel increase

Engineering Contradiction:
Improvestructure complexityVSAvoidvibration and shock
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a leftward-rightward shock absorber as an intermediary component between the guiding wheel and the guiding rail. This shock absorber mediates the interaction by absorbing lateral vibrations and shocks, reducing the harmful effects transmitted to the vehicle body while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Force

If the rotation control spring generates initial rotational displacement, then the spring can control rotation, but the traveling wheel develops arbitrary steering angle causing one-sided wear

Engineering Contradiction:
Improverotational control forceVSAvoidtire wear uniformity
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The patent adjusts the parameters of the rotation control springs to eliminate initial rotational displacement. By carefully selecting spring preloads and stiffness values, the system achieves neutral alignment of the traveling wheel in straight travel, preventing arbitrary steering angles and ensuring uniform tire wear.

Inventive Principle:
Principle #35Parameter changes

4Force

If excessive guiding load occurs on the guiding wheel at specific position, then the bogie can be controlled, but the passenger's feeling of riding comfort decreases and vibration increases

Engineering Contradiction:
Improveguiding loadVSAvoidriding comfort
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The patent introduces dynamic damping elements that adapt to varying guiding loads. The damping characteristics change based on the magnitude and direction of forces, allowing the system to handle excessive guiding loads without transmitting harsh vibrations to the passenger compartment, thereby maintaining riding comfort.

Inventive Principle:
Principle #15Dynamics

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

Prevents excessive rotational movement and reduces leftward-rightward vibrations, enhancing riding comfort and stability while allowing for easy replacement of damaged components.

Implementation Method 1

a return spring that is disposed between a frame thereof and a vehicle body for accommodating passengers and/or baggage and which exerts the same magnitude of force when compressed or stretched

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

install a leftward-rightward shock absorber behind the guiding wheel in order to increase the transportation capacity by increasing a maximum speed of the rubber-tired light rail vehicle

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP3848269B1Bogie for rubber-tired light rail vehicle
Publication Date: 2023.08.09 KOREA RAILROAD RESEARCH INSTITUTE
  • EP3848269B1 patent drawingFigure 1~2
  • EP3848269B1 patent drawingFigure 3~4(b)
  • EP3848269B1 patent drawingFigure 5~6(b)

AI summary

Provided is a bogie for a rubber-tired light rail vehicle. The bogie for a rubber-tired light rail vehicle includes a return spring between a vehicle body accommodating a passenger and/or baggage and a bogie frame, with the same magnitude of force being applied to the return spring when the return spring is compressed or decompressed. Thus, when a rubber-tired light rail vehicle travels in a curved section, excessive rotational movement of the bogie is prevented, and shock or vibration in a leftward-rightward direction is reduced, thereby preventing a decrease in a feeling of riding comfort and improving stability of vehicle traveling.