Hydraulic Drive Flow Control Using Speed-Based Displacement Adjustment
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Solution Overview
Problem
Conventional hydraulic drives with hydrostatic pumps and mechanical control systems face challenges in maintaining a constant flow rate due to external influences, as they rely solely on swivel angle or pressure control, which is not adaptable to consumer load changes.
Innovation Solution
A method for controlling a hydraulic drive with an electronically controllable hydraulic machine that adjusts displacement volume based on consumer load, using electronic signal processing to regulate flow and pressure independently, incorporating a control circuit that detects actual speed and target volume flow to calculate and control displacement volume and operating variables.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional hydraulic-mechanical control of swivel angle is used, then displacement accuracy is improved, but pressure control capability is lost
Solution Approach 1:
The patent combines swivel angle control and pressure control into a unified electronic control system. The control unit receives both a swivel angle specification and a pressure specification, then determines the swivel angle based on both parameters, enabling the hydraulic machine to simultaneously achieve precise displacement control and pressure control that were previously mutually exclusive in conventional mechanical control systems.
2Stress or pressure
If pressure control is used, then pressure regulation is improved, but constant flow rate delivery is lost
Solution Approach 1:
The control system dynamically adjusts the swivel angle based on both the pressure specification and the actual speed of the hydraulic machine. By continuously adapting the displacement based on operating conditions, the system can maintain constant flow rate delivery while simultaneously achieving pressure regulation, resolving the contradiction between these two control modes.
3Adaptability or versatility
If electronic control with both swivel angle and pressure specifications is implemented, then control versatility is improved, but control complexity is increased
Solution Approach 1:
The patent replaces complex mechanical control systems with an electronic control unit that processes both swivel angle and pressure specifications. This electronic substitution simplifies the overall control architecture by using software-based logic to determine the optimal swivel angle based on multiple inputs, rather than requiring complex mechanical linkages and sensors for each control parameter.
Data Source
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AI summary
The invention relates to a method using a hydraulic drive which has at least one hydraulic machine comprising an adjustable displacement volume which, in order to supply pressure medium to at least one hydraulic consumer, can be electronically controlled based on the load thereof, the method at least comprising the steps of: identifying an actual rotational speed and a target volume flow rate, in each case of the hydraulic machine; and calculating a target displacement volume of the hydraulic machine on the basis of the actual rotational speed and the target volume flow rate.