Bogie Suspension Traction Device for Low-Floor Rail Vehicles

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Solution Overview

Problem

Existing bogies for low-floor articulated rail vehicles have poor curving performance, high floor height, and cumbersome traction systems, which affect stability, ride comfort, and maintenance costs.

Innovation Solution

A bogie design featuring two groups of swing bolster mechanisms connected via rotary and traction rod mechanisms, with a lifting device and oiling system, to improve curving performance, reduce floor height, and enhance ride comfort and reliability, while simplifying the structure and reducing weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If traditional bogie structure is used, then floor height is reduced, but curving performance deteriorates

Engineering Contradiction:
Improvefloor heightVSAvoidcurving performance
Core Design Contradiction:
ShapeVSEase of operation

Solution Approach 1:

The bogie structure is segmented into independent functional modules: swing bolsters for curving, traction rod mechanisms for force transmission, and suspension systems for stability. This segmentation allows each component to optimize its function without compromising overall performance, enabling low floor height while maintaining excellent curving capability through the swing bolster's independent rotation capability.

Inventive Principle:
Principle #1Segmentation

2Force

If complex traction device is used, then traction force is improved, but structure complexity increases

Engineering Contradiction:
Improvetraction forceVSAvoidstructure complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent merges the traction and braking force transmission functions into a single integrated traction rod mechanism. The traction rod directly connects the swing bolster to the frame, combining both traction and braking capabilities in one simple structural element, thereby achieving strong traction force while minimizing structure complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The traction rod mechanism serves multiple functions simultaneously: it transmits traction force, transmits braking force, and accommodates the longitudinal movement of the swing bolster. This multi-functionality eliminates the need for separate mechanisms for each function, reducing overall system complexity while maintaining effective force transmission.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Area of stationary object

If swing bolster mechanisms are closely connected, then space utilization is improved, but vibration transmission increases

Engineering Contradiction:
Improvespace utilizationVSAvoidvibration transmission
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The central cross beam acts as an intermediary structure between the two swing bolster mechanisms. It provides a rigid mounting platform that spatially separates the connection points of the two mechanisms, allowing compact arrangement while preventing direct vibration transmission between adjacent bolsters through the frame structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of manufacture

If number of bogies is reduced, then manufacturing cost is improved, but load bearing capacity deteriorates

Engineering Contradiction:
Improvemanufacturing costVSAvoidload bearing capacity
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The swing bolster mechanism introduces dynamic adaptability to the bogie structure. The ability of the swing bolster to rotate and adjust its position allows a single bogie to handle varying load conditions and curving requirements more effectively, compensating for the reduced number of bogies while maintaining adequate load bearing capacity through optimized force distribution.

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

The design enhances curving performance, reduces floor height for easier access, improves ride comfort, and decreases maintenance costs by simplifying the structure and reducing the number of bogies required.

Implementation Method 1

a slewing bearing (14)

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

a lifting device is provided between the lower portion of the swing bolster and the frame

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Implementation Method 3

the bayonet at the bottom of the lifting rod will be stuck in the lifting opening, playing the role of a vertical stop

Methodology Applied
Scientific EffectImpact Force: Impact Force

Data Source

PatentEP3459809B1Bogie suspension traction device for use in low-floor articulated rail vehicle
Publication Date: 2021.07.07 CRRC QINGDAO SIFANG CO LTD
  • EP3459809B1 patent drawingFigure 1~2
  • EP3459809B1 patent drawingFigure 3~4
  • EP3459809B1 patent drawingFigure 5~6

AI summary

The present disclosure relates to a suspension traction device of a low floor articulated rail vehicle, which comprises swing bolster mechanisms, traction rod mechanisms, primary springs and secondary springs. Two swing bolster mechanisms and two traction rod mechanisms are provided, two swing bolster mechanisms are provided respectively in the middle of two groups of wheel-sets. Each swing bolster mechanism is connected to the frame by a set of traction rod mechanisms and is connected to the vehicle body by means of a rotary mechanism. The disclosure has the advantages of simple and compact structure and light weight. It not only realizes the transmission of the traction and the braking force when the vehicle is running, carries the vertical, horizontal and vertical load, which greatly improves the small curving performance of the vehicle, but also reduces the height of the floor surface and the driving performance of the vehicle has also been greatly improved.