Mower Drive Eccentric Arrangement for Grass Pressing Reduction

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Solution Overview

Problem

Existing mowing devices face issues with mechanical drive systems being heavy, prone to damage, and inefficient energy transmission, while hydraulic systems push down grass and have high energy loss, and most vehicles lack sufficient on-board hydraulics.

Innovation Solution

A mowing device with an eccentric arranged above the cutting blade and a deflection lever connected to both, utilizing a traction mechanism for power transmission within the cross member to prevent grass pressing and reduce damage susceptibility, with options for direct hydraulic motor connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a hydraulic motor is flanged directly to a runner of the drive device, then the arrangement is simpler, but the grass is pushed down and energy transmission loss increases

Engineering Contradiction:
Improvedrive device arrangementVSAvoidgrass pressing
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent moves the eccentric from a horizontal arrangement (above the cutting blade) to a vertical arrangement (below the cross member), changing the spatial dimension of the drive mechanism. This dimensional change allows the hydraulic motor to be mounted on the cross member rather than on the runner, eliminating grass pressing while maintaining simple hydraulic drive architecture

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If cardan shafts are used to transmit power to the eccentric, then the mechanical drive is established, but the construction becomes heavy and easily damaged

Engineering Contradiction:
Improvepower transmissionVSAvoiddrive device weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent replaces the mechanical cardan shaft power transmission system with a hydraulic transmission system. The hydraulic motor converts hydraulic energy directly to rotational motion, eliminating the need for heavy mechanical shafts and gears, thereby reducing weight while improving reliability and reducing energy loss

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Object-affected harmful factors

If the eccentric is arranged above the cutting blade, then the grass pressing is avoided, but the power transmission becomes more complex

Engineering Contradiction:
Improvegrass pressingVSAvoidpower transmission system
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent inverts the conventional arrangement by placing the eccentric below the cross member rather than above the cutting blade. This inversion allows the hydraulic motor to be mounted on the cross member, simplifying the power transmission system while the deflection lever mechanism ensures the cutting blade remains at the optimal height to avoid grass pressing

Inventive Principle:
Principle #13The other way round (Inversion)

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

This configuration minimizes grass pressing, enhances product safety, and reduces energy loss by using a low-loss power transmission system, suitable for various vehicle types including two-wheel tractors, while allowing for efficient energy delivery to the cutting blades.

Implementation Method 1

the at least one cutting blade is mounted in such a way that it can be moved in a direction at least approximately parallel to the cross member in a mowing area via an eccentric

Methodology Applied
Scientific EffectEccentric mechanism: Eccentric

Implementation Method 2

a deflection lever is provided, which is connected on the one hand to the at least one cutting blade and on the other hand to the eccentric

Methodology Applied
Scientific EffectLever mechanism: Lever

Data Source

PatentEP2853142B1Driving device for a mower bar
Publication Date: 2018.05.09 STOCKL FRIEDRICH
  • EP2853142B1 patent drawingFigure 1a
  • EP2853142B1 patent drawingFigure 1b
  • EP2853142B1 patent drawingFigure 1c

AI summary

Drive device (1) for a mowing device, with at least one cross member (2) on which at least one cutting blade (3) is mounted in such a way that it can be moved back and forth in a mowing area in a direction at least approximately parallel to the cross member (2) via an eccentric (5), wherein a drive shaft (4) is provided for the eccentric (5), wherein the eccentric (5) - preferably in the area of ​​one of the two ends of the cross member (2) - is arranged above the at least one cutting blade (3) at least partially, preferably completely, in the mowing area of ​​the at least one cutting blade (3), and wherein a deflection lever (7) is provided which is connected on one side to the at least one cutting blade (3) and on the other side to the eccentric (5).