Cutter Assembly Gear Preload Control to Reduce Gear Chatter
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Solution Overview
Problem
Agricultural windrowers experience gear chatter due to uneven loading of the cutter assembly, leading to premature wear of gears, as the gear train is alternately loaded in different rotational directions during crop cutting operations.
Innovation Solution
A cutter control system that pre-loads the gear train by driving the first gear at a higher speed and the second gear at a lower speed, using a dual motor configuration to maintain torque wind-up in one rotational direction, thereby reducing gear chatter and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single motor drives the gear train in conventional windrowers, then the device complexity is reduced, but gear chatter and premature wear occur due to uneven loading and alternating rotational directions
Solution Approach 1:
The single motor drive system is segmented into two separate motors (first motor and second motor), each driving a respective gear (first gear and second gear) of the gear train. This segmentation allows independent control of each motor to maintain unidirectional loading on the gear teeth, preventing gear chatter and premature wear while distributing the mechanical load more evenly across the gear train.
2Reliability
If dual motors are used to pre-load the gear train, then gear chatter is reduced and gear lifespan is extended, but the device complexity increases
Solution Approach 1:
The first motor and second motor are controlled to create a pre-load condition on the gear train before normal cutting operations begin. By driving the gears at slightly different speeds (first speed and second speed), the system establishes a persistent torque wind-up that maintains the gear teeth in continuous unidirectional contact, preventing the alternating loading that causes gear chatter and extending gear lifespan.
3Reliability
If the first motor drives the first gear at a higher speed, then the gear train is pre-loaded in one direction, but energy consumption increases
Solution Approach 1:
The system utilizes small differential speed parameters between the first motor and second motor to achieve the pre-loading effect. Rather than requiring large speed differences or excessive power, the controller maintains a slight parameter difference (first speed vs. second speed) that is sufficient to create the necessary torque wind-up and unidirectional gear engagement, minimizing energy consumption while ensuring reliable gear operation.
Data Source
AI summary
A work vehicle for cutting crops includes a header a supported by a chassis of the work vehicle. The header includes a cutter assembly having a cutter bar frame supporting a series of rotary cutters arranged in a lengthwise direction. A gear train, having a first gear and a second gear, is coupled to the series of rotary cutters to transfer power thereto. A cutter control system includes a first motor coupled to the first gear of the gear train and a second motor coupled to the second gear of the gear train. A controller, including a processor and memory architecture, is operably connected to the first motor and the second motor to control operation thereof. The cutter control system drives the first gear at a first speed via the first motor and drives the second gear at a second speed via the second motor. The second speed is different than the first speed to pre-load the gear train into enmeshing engagement with each other in one rotational direction.