Adjustable Prestressing Mechanism for Harvester Cutting Knives

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Solution Overview

Problem

Existing cutting mechanisms for harvesting machines, such as self-loading wagons or balers, face difficulties in adjusting the prestressing force of cutting knives due to fixed initial and reduction characteristics, making it challenging to optimize performance under varying conditions like fluctuating foreign bodies, crop throughput, and blade conditions.

Innovation Solution

A cutting unit with adjustable pretensioning means that allow for variable prestressing force settings independently of cutting blade deflection or other conditions, enabling simultaneous and uniform adjustment of all cutting knives, utilizing a combination of lever mechanisms and spring means with adjustable spring strength and distance, facilitated by a drive device and sensors for optimal operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If fixed prestressing force is used in cutting knives, then the structure is simple, but the operating characteristics cannot be optimized under varying conditions

Engineering Contradiction:
Improveadaptability to varying operating conditionsVSAvoidcomplexity of prestressing mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by making the prestressing force adjustable rather than fixed. The prestressing means includes adjustment mechanisms that allow the prestressing force to be varied dynamically according to operating conditions such as crop type, moisture content, and foreign body presence. This transforms a static system into a dynamic one that can adapt to changing requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by allowing modification of the prestressing force magnitude through adjustable prestressing means. The system enables changing key parameters such as spring pre-compression, hydraulic pressure, or elastic element tension to optimize cutting performance under different operating conditions while maintaining the basic structural integrity.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If individual adjustment of each cutting knife is implemented, then the prestressing force can be optimized, but the adjustment complexity and time increase significantly

Engineering Contradiction:
Improveease of prestressing force adjustmentVSAvoidtime for adjustment operations
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent merges the adjustment functions of multiple cutting knives into a single unified adjustment mechanism. The prestressing means is designed to simultaneously adjust the prestressing force for all cutting knives or for groups of knives, eliminating the need for individual adjustment of each knife. This combining approach significantly reduces adjustment time and operational complexity while maintaining uniform optimization across all cutting elements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements universality by designing a multi-functional prestressing adjustment mechanism that can serve multiple cutting knives simultaneously. The adjustment system is designed to provide universal control over the prestressing force, allowing a single adjustment operation to optimize the performance of multiple cutting knives across different operating conditions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If large prestressing force is applied to cutting knives, then cutting performance improves, but the resilience against foreign bodies decreases

Engineering Contradiction:
Improvecutting efficiencyVSAvoidresilience to foreign body collisions
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies dynamics by enabling dynamic adjustment of the prestressing force magnitude. The system can increase prestressing force during normal high-productivity cutting operations to maintain sharp cutting performance, and then reduce the prestressing force when foreign bodies are detected or when operating conditions suggest a need for increased resilience. This dynamic modulation allows the system to optimize both productivity and reliability according to real-time requirements.

Inventive Principle:
Principle #15Dynamics

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 adjustable prestressing force optimizes the operating characteristics of the cutting unit by adapting to different operating conditions, simplifying setup and reducing maintenance and production costs, while ensuring robust and low-maintenance construction.

Implementation Method 1

Federmittel, welche die Hebelmechanismen in eine Stützlage gegen eine Hebellagerungsachse vorspannen

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

Hebelmechanismus, der mit dem jeweiligen Schneidmesser verbunden ist und verstellbar in eine Stützlage einstellbar ist, in der das respective Schneidmesser in der Schneidposition liegt

Methodology Applied
Scientific EffectLever: Lever

Data Source

PatentEP2910104B1Cutting assembly for an agricultural harvester
Publication Date: 2016.08.24 CLAAS SAULGAU GMBH
  • EP2910104B1 patent drawingFigure 1
  • EP2910104B1 patent drawingFigure 2

AI summary

A cutting unit (10) for a harvesting machine (1) comprises a feed drum (20) rotatably mounted about a longitudinal axis of rotation (A1), a plurality of cutting knives (40) which can be pivoted about a pivot axis (A2) from a cutting position, in which the cutting knives are placed in a conveying channel (11) formed on the feed drum for the harvested crop, in a pivoting direction away from the feed drum, and pretensioning means (50) which are configured to provide a pretensioning force for each cutting knife, which pretensions the respective cutting knife in a pivoting direction towards the cutting position, and which are configured to change the magnitude of the pretensioning force. According to the invention, the pretensioning means have force adjusting means (80) which are configured so that the magnitude of the pretensioning force is variably adjustable. This results in improved operating characteristics for the cutting unit.