Segmented Knotter Gear Radial Replacement

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Solution Overview

Problem

The existing knotter gear systems in large square balers require significant time and effort to replace a broken or worn knotter gear, as the entire knotter assembly must be removed axially from the drive shaft.

Innovation Solution

A two-piece knotter gear design is introduced, where the first and second knotter gear sectors are divided at a diametrical line, allowing for radial removal and replacement without the need to remove the entire knotter assembly from the drive shaft.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If the entire knotter assembly is removed axially from the drive shaft to replace the knotter gear, then the knotter gear can be replaced, but significant time and effort are required

Engineering Contradiction:
Improveknotter gear replacementVSAvoidmaintenance downtime
Core Design Contradiction:
Ease of repairVSLoss of time

Solution Approach 1:

The knotter gear is divided into two separate sectors (first knotter gear sector and second knotter gear sector) that can be removed independently from the drive shaft. This segmentation allows the knotter gear to be replaced without removing the entire knotter assembly, thereby reducing maintenance time and effort while maintaining the functional integrity of the complete knotter gear when both sectors are installed together.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If the knotter gear is designed as a single piece, then the structure is simple, but the entire assembly must be removed for replacement

Engineering Contradiction:
Improveknotter gear structureVSAvoidknotter gear replacement
Core Design Contradiction:
Device complexityVSEase of repair

Solution Approach 1:

The knotter gear is segmented into two independent sectors that can be separately installed and removed from the drive shaft. This segmentation increases the ease of repair by allowing partial replacement without complete disassembly, while the modular design maintains relatively simple individual sector structures that can be manufactured and handled independently.

Inventive Principle:
Principle #1Segmentation

3Loss of time

If the knotter gear sectors are removed radially from the drive shaft, then replacement time is reduced, but the removal mechanism must accommodate radial movement

Engineering Contradiction:
Improvegear replacement timeVSAvoidremoval mechanism
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The knotter gear sectors are designed with features that enable radial removal from the drive shaft, such as splined interfaces or keyed connections that allow axial and radial movement. This segmentation and design approach reduces replacement time by allowing quick radial extraction and installation of individual sectors without complex disassembly procedures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The drive shaft incorporates intermediary features such as splines, keys, or tapered surfaces that facilitate the radial removal and reinstallation of the knotter gear sectors. These intermediary elements mediate between the sectors and the drive shaft, enabling simple radial movement while maintaining secure rotational engagement during operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3932184B1Intermittent knotter gear
Publication Date: 2025.01.22 DEERE & CO
  • EP3932184B1 patent drawingFigure 1A
  • EP3932184B1 patent drawingFigure 1B
  • EP3932184B1 patent drawingFigure 2

AI summary

A knotter drive apparatus for a baler includes a knotter gear drive shaft having a drive shaft axis and a shaft outside diameter. A plurality of knotter assemblies are mounted on the knotter gear drive shaft. Each assembly includes a first knotter gear sector including a first sector hub portion and a first sector radial portion. The first sector hub portion includes a central passage at least partly defined in the first sector hub portion for receiving the knotter gear drive shaft. The first sector radial portion extends radially outward from the first sector hub portion relative to the drive shaft axis, and has defined thereon a plurality of intermittent gear tooth segments. The first sector hub portion has a circumferential gap defined therein greater than the shaft outside diameter such that the first knotter gear sector is removable radially, relative to the drive shaft axis, from the knotter gear drive shaft.