Hydropneumatic Crawler Track Damping with Adaptive Throttle

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Solution Overview

Problem

Agricultural working machines with rigidly mounted crawler tracks experience limited ride comfort and impaired driving safety due to high pretensioning forces and vibrations, especially on asphalt roads, and adjusting suspension/damping to changing ground conditions is labor-intensive.

Innovation Solution

A crawler drive system with deflection rollers and support rollers equipped with hydro-pneumatic damping elements and a controlled throttle device that adjusts flow resistance, allowing for adaptive damping during operation to improve suspension and reduce vibrations, featuring fluidically coupled damping elements and a pressure accumulator for enhanced ride comfort and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If rigidly mounted crawler tracks are used, then high pretensioning forces can be applied for improved traction, but ride comfort is limited and driving safety is impaired due to vibrations

Engineering Contradiction:
Improvepretensioning forceVSAvoidride comfort
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

A damping element is introduced as an intermediary component between the support roller and the carriage. This damping element absorbs vibrations and shocks while allowing the crawler track to maintain high pretensioning forces for improved traction, thereby resolving the contradiction between force transmission and ride comfort

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The damping characteristics of the system are made adjustable by providing a controllable throttle device that can modify the damping effect of the damping element. This allows the pretensioning force and damping parameters to be optimized for different operating conditions, improving both traction and ride comfort

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If rigidly mounted crawler tracks are used, then structural stability is maintained, but driving safety is impaired due to vehicle vibrations

Engineering Contradiction:
Improvestructural stabilityVSAvoiddriving safety
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The damping element serves as a mediator that isolates vibrations from the vehicle structure while maintaining the structural stability of the crawler track mounting. This reduces harmful vibrations that compromise driving safety without sacrificing structural integrity

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If spring-loaded and damped suspension support rollers are used, then ride comfort is improved, but adjustment of suspension/damping to changed ground conditions requires great effort

Engineering Contradiction:
Improveride comfortVSAvoidadjustment complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The system enables self-adjustment of damping characteristics through the controllable throttle device, which can be regulated during operation to adapt to different ground conditions without requiring manual intervention or complex adjustment procedures

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The damping characteristics are made dynamically adjustable during operation rather than fixed during manufacturing. The controllable throttle device allows real-time modification of damping parameters to match varying ground conditions, simplifying the adaptation process

Inventive Principle:
Principle #15Dynamics

4Object-affected harmful factors

If larger contact area is achieved through air-filled wheels, then soil compaction is reduced, but space required for wheels increases

Engineering Contradiction:
Improvesoil compactionVSAvoidspace required
Core Design Contradiction:
Object-affected harmful factorsVSVolume of moving object

Solution Approach 1:

The use of air-filled wheels leverages pneumatic principles to create a large contact area with the ground while maintaining a compact wheel structure. The air pressure within the wheels allows them to deform and conform to the ground surface, increasing contact area without proportionally increasing wheel volume

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 system provides improved driving comfort and safety by allowing continuous adjustment of damping to match different driving conditions, reducing the effort required for suspension adjustments and enhancing traction on uneven ground.

Implementation Method 1

at least one deflection roller and/or a support roller is assigned a damping element, in particular a hydro-pneumatic damping element

Methodology Applied
Scientific EffectHydro-pneumatic damping: Hydraulic Accumulator

Implementation Method 2

A first damping element is fluidically connected to a pressure accumulator for a first fluid

Methodology Applied
Scientific EffectFluid compression: Compression

Implementation Method 3

hydro-pneumatic damping element

Methodology Applied
Scientific EffectGas compression: Compression

Implementation Method 4

at least one controlled throttle device is provided which is assigned to a damping element and is designed in such a way that its flow resistance can be adjusted

Methodology Applied
Scientific EffectFluid flow resistance: Drag

Implementation Method 5

The crawler belt is driven in a frictionally engaged and/or positively engaged manner via at least one driven deflection roller

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3483048B1Caterpillar track for an agricultural machine
Publication Date: 2023.07.12 CLAAS INDUSTRIETECHNIK GMBH
  • EP3483048B1 patent drawingFigure 1
  • EP3483048B1 patent drawingFigure 2~5

AI summary

A track drive (10) for an agricultural machine comprises at least a first and a second deflection roller (12, 14), wherein the first deflection roller (12) is mounted on a first support arm (18) and the second deflection roller (14) is mounted on a second support arm (20), at least one support roller (32) arranged between the deflection rollers (12, 14), and a track belt (16) encircling the deflection rollers (12, 14) and the at least one support roller (32), wherein at least one deflection roller (12, 14) and/or one support roller (32) is associated with a damping element (36, 38), in particular a hydropneumatic one. According to the invention, at least one controlled throttling device (46) associated with a damping element (36, 38) is provided, which is designed such that its flow resistance is adjustable, in particular during operation of the track drive (10).