Forestry Vehicle Bogie With Pivotable Center Wheel Hub

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Forestry vehicles equipped with bogie axles face challenges in maintaining load-bearing capacity on soft ground while avoiding soil damage, and existing solutions compromise climbing capabilities when encountering obstacles.

Innovation Solution

A bogie design featuring a swing arm with a pivotable center wheel hub, controlled by a spring and/or damper element, which can swivel relative to the bogie body to maintain ground contact and distribute load uniformly, preventing the vehicle from being supported solely by the center wheel over obstacles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a third or fourth row of wheels is added to reduce ground pressure, then soil damage is prevented, but climbing capabilities over obstacles are lost

Engineering Contradiction:
Improvesoil damageVSAvoidclimbing capability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies the dynamics principle by making the center wheel hub pivotable relative to the bogie body. This allows the center wheel to dynamically adjust its position and maintain ground contact during obstacle crossing, preventing the vehicle from being supported solely by the center wheel while still providing additional support wheels for soft ground conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of wheel hub position by allowing it to pivot between a bearing position (below the line connecting outer wheel hubs) and a rest position (above the line). This parameter change enables the system to adapt to different terrain conditions, maintaining climbing capability while providing soil protection when needed.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If the center wheel hub is fixed in position, then structural simplicity is maintained, but the vehicle cannot adapt to soft ground conditions

Engineering Contradiction:
Improvesoil loadingVSAvoidbogie structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent transforms the fixed center wheel hub into a dynamic, pivotable component that can adjust its position relative to the bogie body. This dynamic adjustment allows the vehicle to adapt to soft ground conditions by distributing load more effectively, while the pivot mechanism remains relatively simple in design.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent segments the bogie structure into distinct functional components: the bogie body, the swing arm, and the pivotable center wheel hub. This segmentation allows each component to perform its specific function independently, with the center wheel hub able to pivot to adjust load distribution on soft ground while maintaining overall structural integrity.

Inventive Principle:
Principle #1Segmentation

3Reliability

If the swing arm is designed with large movement range, then obstacle clearance is improved, but stability on firm ground is reduced

Engineering Contradiction:
Improveobstacle clearanceVSAvoidvehicle stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent uses parameter changes by defining specific positions for the center wheel hub: a bearing position below the line connecting outer wheel hubs for obstacle clearance, and a rest position above the line for stability on firm ground. The system can transition between these parameter states as needed.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies dynamics by allowing the swing arm and center wheel hub to pivot between different positions based on terrain conditions. The swing arm can move to clear obstacles while maintaining connection to the bogie body, providing both obstacle clearance capability and stability when needed.

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

Enhances load-bearing capacity on soft ground and reduces soil damage while maintaining climbing capabilities by ensuring all wheels maintain contact with the ground, even when encountering obstacles, through the controlled movement of the center wheel hub.

Implementation Method 1

a spring and/or damper element (26), which at one end portion (26a) is hinged on the bogie body (12) and at the other end portion (26b) is hinged on the swing arm (20) and by means of which the swing arm (20) is capable of being applied with force

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

a spring and/or damper element (26), which at one end portion (26a) is hinged on the bogie body (12) and at the other end portion (26b) is hinged on the swing arm (20) and by means of which the swing arm (20) is capable of being applied with force

Methodology Applied
Scientific EffectDamper: Damping

Implementation Method 3

the wheel hub for arrangement of the center wheel (24) is configured to pivot between a bearing position, in which a center of the wheel hub is positioned below a line connecting a center of the first wheel hub (14a) and a center of the second wheel hub (14b), and a rest position, in which a center of the wheel hub is positioned above the line connecting a center of the first wheel hub (14a) and a center of the second wheel hub (14b)

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP3556579B1Bogie for a forestry vehicle and vehicle with at least one bogie axle
Publication Date: 2022.02.09 NAF NEUNKIRCHENER ACHSENFABRIK
  • EP3556579B1 patent drawingFigure 1~2
  • EP3556579B1 patent drawingFigure 3~4
  • EP3556579B1 patent drawingFigure 5~6

AI summary

The invention relates to a bogie (10) for a forestry vehicle, comprising a bogie body (12), which has a first wheel hub (14a) for arrangement of a first wheel (16a) and a second wheel hub (14b) for arrangement of a second wheel (16b). The bogie (10) comprises a swing arm (20), which is pivotably hinged at a first end portion (20a) on the bogie body (12) and at a second end portion (20b) comprises a wheel hub (22) for arrangement of a center wheel (24) between the first wheel (16a) and the second wheel (16b). The bogie (10) further comprises a spring and/or damper element (26), which at one end portion (26a) is hinged on the bogie body (12) and at the other end portion (26b) is hinged on the second end portion (20b) of the swing arm (20) and by means of which the swing arm (20) is capable of being applied with force. The invention further relates to a vehicle, in particular a forestry vehicle, comprising at least one bogie axle comprising such a bogie (10).