Hydraulic Drain Amplifier for Fast Closed-Loop Actuator Discharge
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Solution Overview
Problem
Existing hydraulic actuators require a large volume of oil and an external pressure supply, leading to environmental risks and complexity in systems like gas turbines and die-casting machines, due to an open oil circuit.
Innovation Solution
A closed hydraulic system with a piston-cylinder arrangement and a secondary line with a larger cross-section for rapid hydraulic fluid flow, featuring a hydraulic valve that switches positions based on pressure differences to control inflow and outflow, reducing oil volume and environmental risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an open oil circuit with external pressure supply is used, then the hydraulic actuator can function, but the oil volume required is large and environmental risks increase
Solution Approach 1:
The hydraulic actuator uses its own output to generate the pressure needed for actuation. The pump delivers hydraulic fluid to the piston chamber, and the pressure generated by this same hydraulic fluid actuates the valve via the pressure line and amplification mechanism, eliminating the need for external pressure supply
Solution Approach 2:
The invention uses a hydraulic amplification mechanism where a small volume of hydraulic fluid under pressure (in the pressure line) controls a much larger volume of hydraulic fluid (in the piston chamber). This hydraulic leverage allows the system to function with minimal oil volume while maintaining full actuator capability
2Reliability
If an open oil circuit is used, then the hydraulic actuator can operate, but the system complexity increases due to external pressure supply requirements
Solution Approach 1:
The invention combines the pressure generation function and the actuation function into a single integrated system. The pump that delivers hydraulic fluid also generates the pressure that is fed back to control the valve, merging what would otherwise be separate external pressure supply and actuation systems
Solution Approach 2:
The hydraulic fluid serves multiple functions simultaneously: it acts as the working medium to move the piston, it generates the pressure signal for valve control, and it provides the force for actuation. This multi-functionality eliminates the need for separate external pressure supply systems
3Volume of moving object
If a small cross-section line is used for hydraulic flow, then the system is compact, but the outflow speed is insufficient for rapid blocking requirements
Solution Approach 1:
The system dynamically adjusts the flow path cross-section based on operational requirements. During normal operation, the compact small cross-section line is sufficient. During rapid blocking requirements, the valve opens to activate the larger cross-section secondary line, providing the necessary high flow rate temporarily when needed
4Speed
If a larger cross-section secondary line is added for rapid outflow, then the outflow speed increases, but the device complexity increases
Solution Approach 1:
The hydraulic flow path is segmented into two distinct lines: a small cross-section main line for normal operation and a large cross-section secondary line for rapid outflow. A valve controls which line is active, allowing the system to achieve high speed when needed while maintaining compactness during normal operation, with each segment optimized for its specific function
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
Significantly reduces oil volume requirements, minimizing environmental hazards and simplifying containment measures, while enabling rapid control of hydraulic systems with increased efficiency and safety.
Implementation Method 1
If the first piston chamber is to be emptied quickly, the hydraulic machine first sucks the hydraulic fluid out of the first piston chamber via the main line
Implementation Method 2
At a predefined volume flow, depending on the volume flow, an increased pressure arises in the second control line, which is connected between the hydraulic resistance and the first piston chamber
Implementation Method 3
The valve can have a first position 'blocked' and a second position 'flow'. The hydraulic valve is controlled by hydraulic actuators
Implementation Method 4
In order to empty the first piston chamber quickly, the actuator has a secondary line, which has a higher cross section, in particular a significantly higher cross section, than the main line
Data Source
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AI summary
The present invention relates to an actuating drive having a variable-speed pump, as used, for example, in steam turbines, gas turbines and die casting machines. The electrohydrostatic actuating drive (10) has a variable-volume and/or variable-speed hydraulic machine which is driven by an electric motor, for the provision of a volumetric flow of a hydraulic fluid. Furthermore, the actuating drive comprises a cylinder (200) with a piston (210), a piston rod (230) and a first piston chamber (220), a valve (100) with a first position and a second position, which valve (100) can be moved by a first hydraulic actuator into the first position and by a second hydraulic actuator into the second position, wherein the second position controls a greater volumetric flow of the hydraulic fluid than the first position, a sink, a main line (130, 160) which connects a first piston chamber (220) of the cylinder (200) to the sink and in which the hydraulic machine (50) is arranged, an auxiliary line (110, 120) which connects the first piston chamber (220) to the sink and in which the valve (100) is arranged, a first control line (140) to the first hydraulic actuator, and a second control line (150) to the second hydraulic actuator. The actuating drive is characterized in that a hydraulic resistance (180) is arranged in the main line (130, 160) in series with the hydraulic machine (50), the first control line (140) is connected at the main line (130, 160), and the second control line (150) is connected between the hydraulic resistance (180) and the first piston chamber (220).