Dual Sickle Knife Drive Phase Angle Control
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Solution Overview
Problem
Existing crop cutting systems with split or dual sickle bars often experience undesirable vibrations due to uncontrolled phase differences between the sickle bars, which can be detrimental to the cutting process and machine operation.
Innovation Solution
A control system that adjusts the phase angle difference between the sickle bars based on operational conditions, using sensors to maintain a 180-degree phase difference when not cutting and a variable phase difference, typically around 90 degrees, when cutting, to optimize cutting efficiency and reduce vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the two sickle bars are driven by independent drive systems with no control over phase difference, then the device complexity is reduced, but undesirable vibrations are generated when the sickle bars are in phase
Solution Approach 1:
The patent employs a control system that continuously monitors the phase difference between the two sickle bars and adjusts the drive phase angle accordingly. Sensors detect the position of each sickle bar, and the control system processes this information to maintain the desired phase relationship, thereby eliminating vibrations caused by in-phase operation.
Solution Approach 2:
The patent implements a dynamic phase angle adjustment mechanism that allows the phase difference between the two sickle bars to be varied in real-time based on operational conditions. This dynamic control enables the system to transition between different phase relationships (e.g., in-phase for cutting, out-of-phase for transport) to optimize performance and minimize vibrations.
2Object-generated harmful factors
If the sickle bars are maintained at a fixed 180-degree phase difference, then vibrations are reduced during transport, but cutting efficiency is compromised when crop is present
Solution Approach 1:
The patent implements a dynamic phase angle adjustment mechanism that allows the phase difference between the two sickle bars to be varied in real-time based on operational conditions. This dynamic control enables the system to transition between different phase relationships (e.g., in-phase for cutting, out-of-phase for transport) to optimize performance and minimize vibrations.
Solution Approach 2:
The patent changes the phase angle parameter between the two sickle bars depending on the operational mode. During transport, the phase difference is maintained at 180 degrees to minimize vibrations, while during cutting operations, the phase difference is adjusted to a smaller value (e.g., 0-90 degrees) to improve cutting efficiency by ensuring continuous crop engagement.
3Object-generated harmful factors
If the phase angle difference is varied dynamically based on operational conditions, then both vibration reduction and cutting efficiency are optimized, but the device complexity increases
Solution Approach 1:
The patent employs a control system that continuously monitors the phase difference between the two sickle bars and adjusts the drive phase angle accordingly. Sensors detect the position of each sickle bar, and the control system processes this information to maintain the desired phase relationship, thereby eliminating vibrations caused by in-phase operation.
Solution Approach 2:
The patent replaces complex mechanical phase control mechanisms with an electronic control system that uses sensors and a controller to adjust the phase angle. This substitution simplifies the overall system by using electronic control instead of complex mechanical linkages, while still achieving the desired vibration reduction and cutting efficiency optimization.
Data Source
Figure 1
Figure 1A
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AI summary
A sickle cutting system is mounted on a header for forward travel over ground having a standing crop thereon and includes a cutter bar with a plurality of knife guards and two sickle bars driven at a phase angle difference where the drive system has a phase difference control component operable to drive the first and second sickle bars at a first phase angle difference typically at or around 180 degrees difference to minimize vibration when no cutting action is occurring and at a second phase angle difference which can be at or around 90 degrees to minimize variations in loading applied to the drive system when the cutting action is taking place.