Active Steering Bogie Leverage Mechanism for Railway Vehicles

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Solution Overview

Problem

Conventional railway bogies lack sufficient steering force to counteract centrifugal forces, leading to increased noise, vibration, and the risk of derailment due to complex construction and heavy weight from torque reducers.

Innovation Solution

An active steering bogie using leverage to actuate steering links with a small force, eliminating the need for reducers and simplifying the construction, allowing for improved maintainability and enhanced steering responsiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If conventional bogies use torque reducers to increase steering force, then steering force is improved, but weight and device complexity increase

Engineering Contradiction:
Improvesteering forceVSAvoidbogie weight
Core Design Contradiction:
ForceVSWeight of stationary object

Solution Approach 1:

The patent replaces the conventional mechanical torque reducer system with a lever-based mechanical advantage system. The lever arm connected to the actuator creates rotational motion that amplifies steering force without requiring a torque reducer, thereby reducing weight while maintaining sufficient steering force to counteract centrifugal forces.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the mechanical parameters by using a lever arm with specific length ratios to achieve mechanical advantage. By adjusting the lever arm dimensions and pivot point positions, the system transforms small actuator forces into large steering forces, eliminating the need for torque reducers and reducing overall bogie weight.

Inventive Principle:
Principle #35Parameter changes

2Force

If torque reducers are added to increase steering force, then steering force is improved, but device complexity and maintainability worsen

Engineering Contradiction:
Improvesteering forceVSAvoidconstruction complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent substitutes the complex torque reducer mechanism with a simple lever-based system. The lever arm rotates about a pivot point connected to the actuator, creating a mechanically advantageous system that requires no additional reduction gears, belts, or complex transmission components, thereby simplifying the overall construction.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and removes the torque reducer component from the steering system, retaining only the essential lever arm and pivot point mechanism. This extraction eliminates unnecessary complexity while preserving the core function of force amplification through mechanical advantage.

Inventive Principle:
Principle #2Taking out (Extraction)

3Device complexity

If conventional bogies are used, then structure is simple, but steering force is insufficient to counteract centrifugal force

Engineering Contradiction:
Improveconstruction simplicityVSAvoidsteering force
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

The patent modifies the conventional simple structure by introducing a lever arm with optimized dimensional parameters. The lever arm length, pivot point position, and connection geometry are specifically designed to provide mechanical advantage, transforming the simple structure into one that delivers sufficient steering force without adding excessive complexity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamic elements to the simple conventional structure by allowing the lever arm to rotate freely about the pivot point. This rotational degree of freedom enables the system to dynamically adapt to steering requirements and generate the necessary centrifugal counteracting force through lever arm motion driven by the actuator.

Inventive Principle:
Principle #15Dynamics

4Force

If friction between wheel flange and lateral rail face increases, then steering force is improved, but noise and vibration increase

Engineering Contradiction:
Improvesteering forceVSAvoidnoise and vibration
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary steering action by using the lever-based system to proactively guide the wheel shaft through the curve before excessive centrifugal force builds up. The actuator-driven lever arm continuously adjusts the steering angle, preventing the wheel flange from pressing against the lateral rail face, thereby eliminating the source of noise and vibration while maintaining adequate steering force.

Inventive Principle:
Principle #10Preliminary action

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 significantly reduces the weight of the bogie, improves steering ability, and enhances driving stability and comfort by allowing greater wheel displacement with less actuator force, preventing derailment and minimizing wheel and rail vibrations.

Implementation Method 1

a lever arm having one end pivotally connected to one of the axle boxes and having the other end connected to an actuator; when the actuator operates, the lever arm rotates about the pivot point, thereby steering the wheel shaft

Methodology Applied
Scientific EffectLeverage: Lever

Data Source

PatentEP2086812B1Active steering bogie for railway vehicles using leverage
Publication Date: 2015.11.18 KOREA RAILROAD RESEARCH INSTITUTE
  • EP2086812B1 patent drawingFigure 1
  • EP2086812B1 patent drawingFigure 2~3
  • EP2086812B1 patent drawingFigure 4~5

AI summary

An active steering bogie for railway vehicles can improve the driving stability of a railway vehicle running at a high speed, thereby increasing the stability of the vehicle, so that the vehicle is not derailed, and can also minimize the vibration of wheels and rails during the driving of the vehicle, thereby ensuring driving comfort. The active steering bogie uses leverage, has a simple structure of links for steering wheel shafts of the bogie, and can use leverage to actuate the links with a small force, thereby reducing the weight of the bogie and facilitating maintenance. The active steering bogie includes a front steering unit, hinged to front axle boxes on both sides of a front wheel shaft to steer the front wheel shaft; and a rear steering unit, hinged to rear axle boxes on both sides of a rear wheel shaft to steer the rear wheel shaft.