Mulching Tool Coupling With Break-Pin Overload Protection

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Solution Overview

Problem

Existing mulching devices for corn harvesting are prone to damage due to excessive torque when encountering stones or obstacles, leading to potential damage to the drive train and gearbox, as their design does not effectively absorb forces acting transversely to the axis of rotation.

Innovation Solution

A mulching device equipped with an overload protection system featuring connecting means with pins that break off in case of excessive torque, allowing the tool to tilt and absorb transverse forces, thereby protecting the drive train and gearbox from damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the mulching device uses a rigid connection between the drive shaft and tool, then torque transmission is efficient, but the device is vulnerable to damage from transverse forces when hitting stones or obstacles

Engineering Contradiction:
Improvetorque transmission efficiencyVSAvoidresistance to damage from transverse forces
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The connection between the drive shaft and tool is made dynamic rather than rigid. The tool can tilt relative to the drive shaft when subjected to transverse forces, allowing the system to adapt to obstacles like stones. This dynamic connection maintains torque transmission while protecting against damage through controlled movement.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

An intermediary mechanism is introduced between the drive shaft and tool that allows selective movement. This intermediary enables the tool to tilt when hit by stones while maintaining the driving connection, acting as a mediator that balances torque transmission with impact absorption.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the mulching device allows the tool to tilt freely to absorb transverse forces, then damage protection is improved, but torque transmission reliability deteriorates

Engineering Contradiction:
Improvedamage protectionVSAvoidtorque transmission reliability
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

The connection is designed to be dynamic under transverse loading (allowing tilt) but maintains rigidity under normal operating conditions. The tool tilts only when subjected to impact forces from stones or obstacles, while maintaining secure attachment during normal mulching operations for reliable torque transmission.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Different parts of the connection have different properties: the connection allows rotational movement (tilt) in response to transverse forces but maintains firm attachment for torque transmission. This local differentiation of connection properties enables both damage protection and reliable power transmission.

Inventive Principle:
Principle #3Local quality

3Reliability

If the mulching device uses a complex overload protection mechanism, then damage protection is improved, but device complexity increases

Engineering Contradiction:
Improveoverload protectionVSAvoidcomplexity of protection mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The overload protection is achieved through the inherent dynamic capability of the tool's mounting connection rather than a separate complex mechanism. The tool's ability to tilt relative to the drive shaft provides automatic overload protection without requiring additional components, keeping the device simple.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The connection mechanism itself provides overload protection through its dynamic properties. When excessive transverse forces occur, the tool automatically tilts to absorb the impact, and the connection self-regulates to maintain proper operation under normal conditions, eliminating the need for separate protection mechanisms.

Inventive Principle:
Principle #25Self-service

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 overload protection system effectively prevents damage to the mulching device by allowing the tool to tilt and absorb transverse forces, reducing the risk of gearbox and drive train damage when encountering obstacles, with the broken pins being replaceable and the tool remaining securely attached to the holder.

Implementation Method 1

The overload protection device is configured to break when a maximum torque acting between the drive shaft and the tool is exceeded

Methodology Applied
Scientific EffectFracture Mechanics: Fracture Mechanics

Data Source

PatentEP3881665B1Mulching apparatus for processing plant stubble
Publication Date: 2023.11.22 DEERE & CO
  • EP3881665B1 patent drawingFigure 1
  • EP3881665B1 patent drawingFigure 2~3
  • EP3881665B1 patent drawingFigure 4~5

AI summary

A mulching device (50) for processing plant stubble (80) comprises a drive shaft (56), a tool (54) coupled to the drive shaft (56) for processing the plant stubble (80) and connecting means (64) for torque-transmitting connection of the drive shaft (56) to the tool (54), which includes an overload protection.