Dolly Axle Steering Geometry for Snaking Reduction

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Solution Overview

Problem

Long vehicle combinations experience snaking and swaying issues due to inadequate steering behavior, particularly in existing dolly axles that rely on complex sensors and motor drives.

Innovation Solution

The dolly axle incorporates a steering geometry with a steering damper and rotatable saddle coupling, adjustable distance ratios for steering angle correction, and dampers on both sides of the drawbar to reduce snaking and swaying, along with a reversing lock and height-adjustable fastening arrangement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex sensors and motor drives are used in dolly axles, then steering precision can be improved, but device complexity and cost increase

Engineering Contradiction:
Improvesteering precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex electronic steering systems with a purely mechanical linkage system. The drawbar is mechanically connected to the steering lever through a linkage mechanism that automatically converts drawbar pivoting movements into wheelset steering angles, eliminating the need for sensors, motors, and electronic control systems while maintaining steering precision

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

Solution Approach 2:

The mechanical linkage system is self-actuating, using the natural pivoting movement of the drawbar during vehicle operation to automatically steer the wheelsets. The system requires no external power source or active control, as the geometry of the linkage automatically translates drawbar angle changes into appropriate steering angles

Inventive Principle:
Principle #25Self-service

2Ease of manufacture

If fixed steering geometry is used in dolly axles, then manufacturing simplicity is maintained, but adaptability to different driving conditions deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidadaptability to driving conditions
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent implements a dynamic steering geometry where the linkage parameters can be adjusted during operation or manufacturing. The linkage includes adjustable connection points and variable geometry elements that allow the steering ratio and response characteristics to be modified based on driving conditions, vehicle load, and maneuvering requirements, transitioning from static to adaptive behavior

Inventive Principle:
Principle #15Dynamics

3Speed

If drawbar pivoting movements are directly transmitted to wheelsets, then steering response is improved, but tire wear and rolling resistance increase due to incorrect steering angles

Engineering Contradiction:
Improvesteering response speedVSAvoidtire wear and rolling resistance
Core Design Contradiction:
SpeedVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a mechanical linkage system as an intermediary between the drawbar and the steerable wheelset. This linkage includes a drawbar connection, control arms, and steering levers that mediate the transmission of steering movements. The intermediary mechanism transforms the raw drawbar pivoting into corrected steering angles that account for vehicle geometry and driving conditions, ensuring optimal tire contact and reducing wear while maintaining responsive steering

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This configuration improves steering behavior, reduces tire wear and rolling resistance, and prevents rocking, allowing for smoother vehicle maneuverability and reduced stress on steering components.

Implementation Method 1

the dolly axis of the type mentioned is characterized in that a steering damper is provided, on which the drawbar acts in an articulated manner

Methodology Applied
Scientific EffectDamping: Damping

Implementation Method 2

specifically in its neutral position, in a spring-loaded reversing locking claw which can be connected to the drawbar

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP1900610B1Dolly axle
Publication Date: 2010.02.10 FAHRZEUGWERK BERNARD KRONE
  • EP1900610B1 patent drawingFigure 1
  • EP1900610B1 patent drawingFigure 2
  • EP1900610B1 patent drawingFigure 3

AI summary

The dolly-axle has a pulling drawbar (6) fastened to a frame (4) and rotatable movable around a rotation axis. A saddle coupling (8) is arranged on an upper side of the frame, and a wheel set (10) is supported at a wheel axis (12.1). A switching guide is provided as a transmission unit and transfers the rotating movement of the drawbar to a steering lever acting on the wheel set, where the position of the guide is changed by an adjusting unit. The rotation axis of the drawbar is situated in a forward driving direction before the wheel axis.