Reversible Reel Motor System for Automatic Debris Clearing

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Solution Overview

Problem

Grass mowing machines often face issues with cutting reels getting stuck due to rust or clogging with debris, which can lead to motor damage and require manual intervention, disrupting productivity and safety.

Innovation Solution

A system with an electric or hydraulic reel motor that alternates between forward and reverse rotation commands until the reel motor rotates sufficiently, allowing for automatic clearing of stuck reels without operator intervention and maintaining productivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the reel motor provides high torque to start a stuck reel, then the reel can be cleared more effectively, but the motor may not have sufficient torque available and could be damaged

Engineering Contradiction:

Improvereel clearing effectivenessVSAvoidmotor torque capacity

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The system applies periodic reverse rotation commands to the reel motor at intervals during startup attempts. When the reel fails to reach minimum speed within a threshold time, the controller commands the motor to reverse rotate for a specified duration, then pauses before attempting forward rotation again. This periodic reverse action prevents continuous high torque application that could damage the motor while effectively clearing stuck reels by loosening debris accumulations over time.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system reverses the rotation direction of the reel motor when a startup failure is detected. Instead of continuously applying forward torque that may cause motor damage, the controller commands reverse rotation to loosen the stuck condition. This inversion of the normal rotation direction allows the motor to clear debris and thatch accumulations without exceeding its torque capacity, thereby protecting the motor while maintaining clearing effectiveness.

Inventive Principle:

Principle #13The other way round (Inversion)

2Ease of operation

If the operator manually cleans the reel by hand, then the reel can be cleared of debris, but the operator must shut off the engine and PTO, reducing productivity

Engineering Contradiction:

Improvereel clearing safetyVSAvoidmowing operation continuity

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The system enables the reel to clear itself of debris and thatch accumulations through automated reverse rotation commands. When a startup failure indicates a stuck reel, the controller automatically commands the motor to reverse rotate for a specified time, then attempts forward rotation again. This self-service clearing mechanism eliminates the need for operator intervention and shutdown of the engine and PTO, thereby maintaining productivity while ensuring safe operation.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system monitors reel motor performance during startup by detecting whether the reel reaches minimum speed within a threshold time. When startup failure is detected, the controller provides feedback by commanding reverse rotation to clear the stuck condition. This feedback-based automated response allows the system to detect and clear stuck reels without operator intervention, maintaining both safety and productivity by keeping the engine and PTO running.

Inventive Principle:

Principle #23Feedback

3Reliability

If the system attempts to start the reel multiple times, then the reel may clear itself, but time is lost and productivity is reduced

Engineering Contradiction:

Improvereel startup successVSAvoidstartup delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system implements periodic reverse rotation commands with specific timing intervals during startup attempts. When the reel fails to reach minimum speed within a threshold time, the controller commands reverse rotation for a predetermined duration, then pauses before attempting forward rotation again. This structured periodic action with optimized timing allows the reel to clear itself efficiently, minimizing startup delay while maximizing the likelihood of successful startup.

Inventive Principle:

Principle #19Periodic action

4Ease of operation

If the operator intervenes to clean the reel, then the reel can be cleared safely, but operator intervention is required and productivity decreases

Engineering Contradiction:

Improvereel clearing safetyVSAvoidoperator intervention requirement

Core Design Contradiction:

Ease of operationVSExtent of automation

Solution Approach 1:

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS7797915B1System to clear stuck reels on grass mowing machine

Publication Date: 2010.09.21 DEERE & CO

AI summary

A system to clear stuck reels on a grass mowing machine with a reversible electric or hydraulic motor connected to a cutting reel. The reel motor can rotate in a forward direction and a reverse direction. A controller provides electric signals to the reel motor, and commands the motor to reverse direction if the reel motor does not rotate in the forward direction at a rotational speed at least as high as a preset minimum speed, or rotate a pre-specified number of revolutions.