Mulching Tool Pendulum Suspension Center of Mass Balancing

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Solution Overview

Problem

Existing mulching devices for processing plant stubble face issues with tool deformation and premature wear due to rigid attachments, and inefficiencies in material usage, leading to high manufacturing costs and potential tilting moments that affect performance.

Innovation Solution

A mulching device with tools mounted in a freely oscillating manner using pendulum bearings, featuring a fastening area and processing body with an asymmetric shape where the center of mass lies in the plane of symmetry, allowing for a more efficient and cost-effective design that avoids tilting moments and deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If tools are rigidly attached to the shaft, then structural stability is improved, but tool deformation increases upon collision with foreign objects

Engineering Contradiction:
Improvestructural stabilityVSAvoidtool deformation resistance
Core Design Contradiction:
Stability of the object's compositionVSStrength

Solution Approach 1:

The tool is changed from a rigid attachment to a dynamic pendulum suspension system. The tool can now swing freely around a horizontal axis perpendicular to the shaft rotation axis, allowing it to absorb impact forces from foreign objects through controlled movement rather than rigid deformation. The pendulum bearing enables this dynamic response while maintaining operational stability during normal mulching operations.

Inventive Principle:
Principle #15Dynamics

2Strength

If pendulum suspension is used, then tool deformation resistance is improved, but tilting moment on self-aligning bearing increases due to vertical asymmetry

Engineering Contradiction:
Improvetool deformation resistanceVSAvoidtilting moment on bearing
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The tool is deliberately designed with vertical asymmetry in its working geometry to optimize mulching performance, while the pendulum suspension system compensates for the resulting tilting moment. The asymmetric shape allows the cutting edge to engage plant material effectively, and the pendulum bearing absorbs the resulting unbalanced forces, preventing premature wear and maintaining reliable operation.

Inventive Principle:
Principle #4Asymmetry

3Object-generated harmful factors

If solid cylindrical bodies are used, then tilting moment is reduced, but material usage increases with upper half not interacting with plant stumps

Engineering Contradiction:
Improvetilting moment reductionVSAvoidmaterial usage efficiency
Core Design Contradiction:
Object-generated harmful factorsVSLoss of substance

Solution Approach 1:

The tool geometry is segmented and optimized so that only the necessary portions of material are present. Instead of using complete solid cylinders, the tool features a selectively distributed mass configuration where material is concentrated in regions that actively engage with plant stumps during rotation. This reduces unnecessary material while maintaining balanced operation and minimizing tilting moments on the bearing.

Inventive Principle:
Principle #1Segmentation

4Loss of substance

If asymmetric tool shape is used, then material usage efficiency is improved, but manufacturing precision requirements increase to balance center of mass

Engineering Contradiction:
Improvematerial usage efficiencyVSAvoidcenter of mass positioning
Core Design Contradiction:
Loss of substanceVSManufacturing precision

Solution Approach 1:

The tool design incorporates self-balancing features where the asymmetric geometry is configured to naturally position the center of mass in a location that minimizes tilting moments on the pendulum bearing. The mass distribution is arranged so that the tool's own geometry provides the balancing effect, reducing the need for post-manufacturing adjustments and simplifying the precision requirements while maintaining material efficiency.

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 solution enables effective defibration of plant stubble with reduced material usage and lower manufacturing costs, while maintaining tool stability and extending the lifespan of self-aligning bearings.

Implementation Method 1

the tool is deformed to at least a greater extent than with a pendulum suspension (which allows the tool to deflect backward relative to the driving shaft)

Methodology Applied
Scientific EffectPendulum motion: Pendulum

Implementation Method 2

any vertical asymmetry of the tool is compensated for by a spherical shape of the pendulum bearing, which allows movement of the tool relative to the holder about an axis oriented tangentially to the direction of rotation of the tool

Methodology Applied
Scientific EffectSelf-aligning mechanism: Ball Bearing

Data Source

PatentEP3918903B1Tool for a mulching apparatus for processing plant stumps on a field
Publication Date: 2024.12.25 DEERE & CO
  • EP3918903B1 patent drawingFigure 1
  • EP3918903B1 patent drawingFigure 2
  • EP3918903B1 patent drawingFigure 3

AI summary

A tool (54) for a mulching device (50) for processing plant stubble in a field comprises: a mounting area (72) configured to be coupled to a support (56) via a pivoting axis of rotation (84) and through which an imaginary plane of symmetry (90) oriented orthogonally to the axis of rotation (84) passes, and a processing body (70) configured to shred the plant stubble standing in a field and which is asymmetrically shaped along the axis of rotation (84), wherein the tool (54) is shaped such that its center of mass (82) lies in the plane of symmetry (90).