Combine Harvester Chaff Mill Variable-Speed Drive for Power and Wear

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Solution Overview

Problem

Existing weed seed mills in agricultural harvesters operate at a single constant speed, leading to inefficient power consumption, premature wear, and increased operational costs due to unnecessary engine draw, especially when processing minimal chaff.

Innovation Solution

A gearbox is integrated into the drive system to allow the chaff mill rotor to operate at least two different speeds, optimizing power usage and reducing wear by varying the rotational speed based on processing demands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the weed seed mill operates at a single constant speed, then the drive system is simple and reliable, but power consumption is high and wear is increased when processing minimal chaff

Engineering Contradiction:
Improvepower consumptionVSAvoiddrive system complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by transitioning from a fixed-speed drive system to a variable-speed drive system. The mill rotor speed can now be adjusted dynamically based on processing conditions, allowing the system to operate at lower speeds when processing minimal chaff, thereby reducing power consumption and wear while maintaining the ability to operate at higher speeds when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying the operational speed parameter of the mill rotor. Instead of maintaining a constant speed, the system now allows the speed parameter to vary according to processing demands. This is achieved through a variable-speed drive mechanism that can adjust the rotational speed of the mill rotor, enabling optimization of power consumption and wear characteristics.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the weed seed mill operates at high constant speed, then seed destruction performance is maintained, but mill wear increases and operational efficiency decreases

Engineering Contradiction:
Improveseed destruction performanceVSAvoidmill longevity
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The variable-speed drive system allows the mill to dynamically adjust its operational speed. When processing conditions require high speed for effective seed destruction, the system can operate at high speeds. When processing minimal chaff or under lighter loads, the system reduces speed, thereby reducing wear and extending the duration of action and longevity of the mill components.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If the weed seed mill operates at constant speed, then the drive system is simple, but power consumption is unnecessary when processing minimal chaff

Engineering Contradiction:
Improvedrive system simplicityVSAvoidunnecessary power draw
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The system changes the speed parameter dynamically based on processing conditions. When processing minimal chaff, the mill rotor speed is reduced, thereby reducing power consumption and eliminating unnecessary energy draw from the engine. This parameter adjustment is achieved through a variable-speed drive mechanism that responds to processing demands.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4595742A1Variable speed drive for chaff mill of combine harvester
Publication Date: 2025.08.06 CNH INDUSTRIAL AMERICA LLC
  • EP4595742A1 patent drawingFigure 1
  • EP4595742A1 patent drawingFigure 2
  • EP4595742A1 patent drawingFigure 3A~3B

AI summary

A residue processing system for an agricultural harvester includes a chaff mill for processing a stream of chaff containing weed seeds, and a drive system for powering the chaff mill. The drive system includes a gearbox having (i) an input shaft that either directly or indirectly receives power from an engine or other power source of the agricultural harvester, and (ii) an output shaft that is either directly or indirectly connected to a rotor of the chaff mill for rotating the rotor. The gearbox is configured to selectively rotate the output shaft at at least two different speeds such that the rotor of the chaff mill can be rotated at at least two different speeds.