Closed Center Pump Height Control for Combine Headers
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Solution Overview
Problem
Agricultural combine harvesters face challenges in quickly responding to ground contours due to slow hydraulic circuits, leading to increased energy consumption and fuel usage with open center systems, while closed center systems are slow to react.
Innovation Solution
A closed center hydraulic circuit with a variable displacement pump and a pressure feedback loop, coupled with an electronic control unit and pressure sensor, allows for faster and more efficient feederhouse height control by maintaining commanded pressure and reducing energy waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If an open center hydraulic circuit is used, then the response speed to ground contours is improved, but the energy consumption increases
Solution Approach 1:
The patent employs a variable displacement pump that dynamically adjusts its displacement based on real-time hydraulic circuit conditions and control signals from the electronic control unit, allowing the system to optimize between response speed and energy consumption depending on operational requirements
Solution Approach 2:
The system changes the displacement parameter of the hydraulic pump dynamically, switching between different displacement settings to achieve fast response when needed while minimizing energy consumption during normal operation, directly addressing the contradiction between speed and energy use
2Use of energy by moving object
If a closed center hydraulic circuit is used, then the energy consumption is reduced, but the response speed to ground contours deteriorates
Solution Approach 1:
The variable displacement pump dynamically adjusts its characteristics based on control signals from the electronic control unit, enabling the closed center circuit to achieve fast response when needed while maintaining low energy consumption during steady-state operation
Solution Approach 2:
The electronic control unit receives feedback from sensors monitoring ground contours and hydraulic circuit parameters, using this feedback to adjust pump displacement and valve positions in real-time, ensuring both energy efficiency and rapid response to terrain changes
3Speed
If the hydraulic pump displacement is increased for faster response, then the response speed is improved, but the power demands increase
Solution Approach 1:
The variable displacement pump adjusts its displacement dynamically based on actual operational needs rather than maintaining a fixed high displacement setting, achieving fast response when required while minimizing power consumption during normal operation
Solution Approach 2:
The system uses partial displacement of the pump only when fast response is needed, rather than continuously operating at full displacement, thereby achieving necessary response speed without excessive power demands during all operating conditions
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 solution reduces power demands and fuel consumption, enabling faster response times to ground changes, thus preventing damage to the harvesting head while maintaining efficient operation.
Implementation Method 1
said displacement is controllable by application of hydraulic fluid to a control line of said pump
Implementation Method 2
A pressure sensor responsive to a pressure in the cylinders, wherein the pressure sensor is coupled to the electronic control unit to provide a signal to the electronic control unit, wherein the signal corresponds to the pressure in the cylinders
Implementation Method 3
said hydraulic lift valve being further coupled to the cylinders to supply hydraulic fluid thereto from said pump
Data Source
Figure 1
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AI summary
An agricultural combine (100) has a header height control circuit supplied with hydraulic fluid from a closed center pump (110). The pump (110) has a variable displacement that is controlled by a control line (200) connected to the pump (110). The control line (200) is supplied with fluid from the feederhouse lift cylinders (114) that passes through a valve (206). The valve (206) supplies hydraulic fluid from the feederhouse lift cylinders (114) to the control line (200) of the pump (110). Upon receiving fluid from the valve (206) the closed center pump (110) rapidly changes its outlet pressure to match the pressure in the feederhouse lift cylinders (114) and thus reduces the response time of the closed center pump (110).