Center Drive Sickle Knife Flywheel Vibration Isolation

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Solution Overview

Problem

Current center drive systems for sickle knives in agricultural cutting machines face challenges with high acceleration and deceleration forces, leading to vibration and fatigue in structural components, particularly in larger headers, and require complex mechanical drive lines that add weight and cost.

Innovation Solution

A center drive system utilizing a rotary input drive member with a high-speed flywheel and eccentric mechanisms to provide additional energy and balance forces, reducing vibration and structural stress, while eliminating the need for long drive lines and allowing for a lighter header structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a center drive system is used to eliminate long timing apparatus and reduce header weight, then device complexity and weight are reduced, but high acceleration and deceleration forces generate vibration and fatigue in structural components

Engineering Contradiction:

Improvedrive line complexityVSAvoidvibration and fatigue

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent applies vibration isolation elements (springs and dampers) between the drive mechanism and header structure to absorb and dissipate the high-frequency vibrations generated by rapid acceleration and deceleration of the knife assembly, thereby reducing transmitted vibration and fatigue to structural components

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The patent incorporates elastic elements and shock-absorbing components in advance within the drive mechanism design to cushion the high impact forces generated during rapid start-stop operations, protecting structural components from fatigue failure before it occurs

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Weight of stationary object

If the drive mechanism is located at the center of the header, then long timing apparatus can be eliminated and header weight reduced, but the structure must accommodate high loads without interfering with crop flow

Engineering Contradiction:

Improveheader weightVSAvoidstructural load capacity

Core Design Contradiction:

Weight of stationary objectVSStrength

Solution Approach 1:

The patent segments the drive mechanism into modular components mounted on a distributed framework rather than a single heavy central structure, allowing the header to support high loads while maintaining reduced overall weight and avoiding interference with crop flow paths

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent positions the drive mechanism in three-dimensional space above and behind the cutter bar, utilizing vertical and rearward space rather than horizontal space across the header width, thereby eliminating long timing apparatus while maintaining structural integrity and crop flow clearance

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Productivity

If two knife assemblies are used on larger headers, then cutting coverage is increased, but acceleration and deceleration forces are doubled generating higher vibration and fatigue

Engineering Contradiction:

Improvecutting coverageVSAvoidvibration and fatigue

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent merges the drive mechanisms of two knife assemblies into a single integrated center drive system, where both knife bars are driven from common mounting points, thereby reducing the number of drive units and timing apparatus while using vibration isolation elements to manage the combined acceleration and deceleration forces

Inventive Principle:

Principle #5Merging (Combining)

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 effectively reduces vibration and structural stress, enhances energy efficiency, and allows for a more compact and maneuverable harvesting machine design without compromising crop flow or increasing weight and complexity.

Implementation Method 1

Methodology Applied

Scientific EffectFlywheel energy storage: Flywheel

Implementation Method 2

A center drive system utilizing a rotary input drive member with a high-speed flywheel and eccentric mechanisms to provide additional energy and balance forces

Methodology Applied

Scientific EffectEccentric mechanism: Eccentric

Data Source

PatentUS11259460B2Center drive for sickle knife

Publication Date: 2022.03.01 MACDON INDS

AI summary

The cutter bar of a header including two sickle bars is driven by a center drive system including a rotary input drive member driven by a motor, first and second rotary members each driven by the drive member about a generally upstanding first rotational axis. Each of the rotary members has an eccentric drive system for driving a respective sickle bar. A flywheel is driven by the rotary input drive member for common rotation therewith and the first and second rotary members are driven by a common drive sprocket to rotate in the same direction about the first and second rotary axes.