Supplemental Hydraulic Pump Control for Low-Speed Flow Demand
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Solution Overview
Problem
Current tractor hydraulic systems experience reduced implement performance due to decreased hydraulic flow at lower engine speeds, leading to increased parasitic power losses from unnecessary pump operation at elevated pressure levels.
Innovation Solution
A hydraulic system with a supplemental pump that operates in a standby condition at lower flow and pressure when additional flow is not needed, switching to higher flow and pressure when required, managed by a controller based on swashplate angle thresholds and load sensing signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If an additional pump operates continuously at elevated pressure levels to provide supplemental flow, then implement performance is improved, but parasitic power losses increase due to unnecessary pump operation
Solution Approach 1:
The supplemental pump's displacement is made dynamically adjustable through a load sensing compensator that automatically modulates the swashplate angle based on real-time pressure differential feedback. This allows the pump to transition from a static high-pressure state to a dynamic state where displacement is continuously optimized according to actual flow demand, eliminating unnecessary energy consumption when supplemental flow is not required
Solution Approach 2:
The system changes the operating parameters of the supplemental pump by introducing a pressure differential threshold mechanism. When the difference between main pump outlet pressure and implement circuit pressure exceeds the threshold, the load sensing compensator increases supplemental pump displacement; when the differential falls below the threshold, displacement is reduced. This parameter-based control resolves the contradiction by adapting pump operation to actual system needs
2Productivity
If the supplemental pump operates at higher flow levels to meet increased hydraulic demand, then implement performance is maintained, but energy consumption increases
Solution Approach 1:
A load sensing compensator establishes a closed-loop feedback system that continuously monitors the pressure differential between the main pump outlet and the implement circuit, then automatically adjusts the supplemental pump's swashplate angle. This feedback mechanism ensures the supplemental pump operates at the minimum necessary flow level to meet implement demands, preventing energy waste from excessive flow delivery while maintaining adequate hydraulic supply
3Productivity
If the hydraulic system is designed for maximum flow at lowest engine speed, then implement performance is maintained at low speeds, but pump size and system complexity increase
Solution Approach 1:
The hydraulic system is segmented into two independent pump circuits: a main pump handling baseline hydraulic demands and a supplemental pump providing additional flow only when needed. This segmentation allows each pump to be optimized for its specific operating range, with the supplemental pump sized appropriately for intermittent high-flow需求的补充，而不是设计一个过大 的主泵 来满足所有情况下的峰值需求，从而在保证低速性能的同时降低了系统复杂性
Data Source
AI summary
A hydraulic system for a work vehicle includes a first pump providing a first flow to a first circuit. A first pressure sensor measures a first pressure in the first circuit. A first swashplate angle sensor measures a first angle of a first swashplate of the first pump. A supplemental pump provides a supplemental flow to a supplemental circuit. A supplemental pressure sensor measures a supplemental pressure in the supplemental circuit. A supplemental valve adjusts the load sense signal provided to a supplemental load sensing compensator of the supplemental pump. A first valve selectively enables flow from the supplemental circuit to the first circuit when the supplemental pressure is equal to or greater than the first pressure. A controller determines to operate the supplemental pump in one of a standby condition and a use condition based in part on the first angle of the first swashplate.