Rail-Wheel Excavator Damping Control for Uneven Track Stability

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Solution Overview

Problem

Excavators with rail wheels can derail due to unevenness in railway tracks, especially when experiencing sudden shifts in center of gravity or load changes, leading to uncontrolled movements.

Innovation Solution

Implementing a controlled damping device between the rail wheel carrier and the chassis, adjustable based on operating parameters such as speed, arm position, and load, to stabilize the excavator on railway tracks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If free vertical movement of the undercarriage relative to the rail wheel carrier is allowed, then the excavator can handle unevenness in railway tracks, but uncontrolled sudden movements occur due to center of gravity shifts and load changes

Engineering Contradiction:
Improveability to handle uneven tracksVSAvoidcontrol stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The damping coefficient of the damping device is dynamically adjusted based on operating parameters (speed, arm position, load) to change the system's mechanical properties. This allows the system to maintain stability across varying operational conditions while still accommodating track unevenness.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The control system continuously monitors operating parameters and adjusts the damping device accordingly. This closed-loop feedback mechanism ensures that the damping force adapts to current operational conditions, preventing uncontrolled movements while maintaining the ability to handle track variations.

Inventive Principle:
Principle #23Feedback

2Stability of the object's composition

If damping effect is increased to prevent uncontrolled movements, then stability improves, but the ability to compensate for track unevenness decreases

Engineering Contradiction:
Improvemovement controlVSAvoidcompensation capability
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The damping device transitions from a static to a dynamic system where the damping coefficient can be adjusted in real-time. This allows the system to optimize between stability and compensation capability depending on the current operational state and track conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

By changing the damping parameter based on operating conditions, the system can provide high damping when stability is critical (e.g., during stationary work) and low damping when compensation for track unevenness is needed (e.g., during movement on variable terrain).

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

Prevents uncontrolled movements and derailment by selectively damping the relative vertical movement between the rail wheel carrier and the chassis, ensuring stable operation even on uneven tracks.

Implementation Method 1

the wheel carrier suspensions each have at least one damping device, the damping effect of which is controlled depending on at least one operating parameter of the excavator, for damping the relative vertical movement between the respective rail wheel carrier and the chassis

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Data Source

PatentEP4678428A1Excavator
Publication Date: 2026.01.14 KAISER AKTIENGES
  • EP4678428A1 patent drawingFigure 1~2
  • EP4678428A1 patent drawingFigure 3~4
  • EP4678428A1 patent drawingFigure 5~6

AI summary

Excavator (1) whose upper carriage (2) is rotatably mounted on an undercarriage (3), the undercarriage (3) having a chassis (6) on which at least two running wheels (7) for traveling on a surface (8) are mounted on each of two longitudinal sides, the undercarriage (3) additionally having at least two rail wheel carriers (9), each of which has at least two rail wheels (10) mounted opposite each other on the rail wheel carriers (9) for traveling on railway tracks (22), and the rail wheel carriers (9) are each mounted on the chassis (6) via a wheel carrier suspension (11) so as to be raised and lowered relative to the chassis (6), and compensation devices (12) enable a relative vertical movement between the respective rail wheel carrier (9) and the chassis (6) caused by external forces, limited by the respective upper stop (13) and the respective lower stop (14), the wheel carrier suspensions (11) each having at least oneThe damping device (15), the damping effect of which is controlled depending on at least one operating parameter of the excavator (1), has a damping device for damping the relative vertical movement. (Fig. 4)