Gas Drive Pressure Control for Load-Independent Piston Speed
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Solution Overview
Problem
Conventional gas-operated drive systems with exhaust air throttling are energetically unfavorable due to constant maximum gas pressure in the driving chamber, leading to load-dependent speed of the working element, whereas supply air throttling results in load-independent speed but is energetically costly.
Innovation Solution
A control valve is used to adjust the opening cross-section based on control pressure, allowing increased gas flow into the driving chamber when pressure falls below a first limit pressure and reducing or closing the valve when pressure drops further, ensuring a supercritical flow and efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If exhaust air throttling is used to maintain supercritical flow, then load-independent speed is achieved, but energy consumption increases due to constant maximum gas pressure
Solution Approach 1:
The control valve dynamically adjusts its opening cross-section based on the control pressure to maintain supercritical flow conditions. When control pressure falls below the first limit pressure, the valve opens to increase gas flow; when pressure falls further below the second limit pressure, the valve closes to reduce energy consumption. This dynamic adjustment resolves the contradiction by adapting the system state to maintain speed independence while optimizing energy use.
Solution Approach 2:
The system changes the opening cross-section parameter of the control valve in response to control pressure changes. By adjusting this parameter, the system maintains supercritical flow (load-independent speed) only when necessary, and transitions to a closed state to reduce energy consumption when the pressure differential is insufficient, thereby resolving the energy-speed contradiction.
2Use of energy by moving object
If supply air throttling is used to reduce energy consumption, then energy efficiency improves, but speed becomes load-dependent
Solution Approach 1:
The control valve acts as an intermediary between the gas source and the driving chamber. Instead of throttling supply air directly (which would make speed load-dependent), the control valve regulates gas flow based on control pressure, using the exhaust air throttle as a mediator to maintain supercritical flow conditions when needed, thus achieving both energy efficiency and load-independent speed.
3Reliability
If control valve opens to increase gas flow, then supercritical flow is maintained, but energy consumption increases
Solution Approach 1:
The system uses control pressure as feedback to determine the opening cross-section of the control valve. When control pressure falls below the first limit pressure, the valve opens to maintain supercritical flow; when pressure falls below the second limit pressure, the valve closes to save energy. This feedback mechanism ensures supercritical flow is maintained only when necessary for reliable operation, optimizing energy consumption.
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
This approach achieves an energetically more favorable mode of operation with load-independent movement of the working element by regulating pressure and reducing energy consumption, maintaining supercritical flow conditions.
Implementation Method 1
the control pressure prevailing in the flow direction in front of the exhaust air throttle or falling above the exhaust air throttle
Implementation Method 2
the opening cross section of the control valve can be adjusted as a function of a control pressure prevailing in the flow direction in front of the exhaust air throttle
Implementation Method 3
pressurised gas from a pressure source which provides gas at a pressure greater than the surrounding atmospheric pressure, e.g. a compressor, is fed into one of the chambers, which exerts a force on the working element which moves the working element
Implementation Method 4
the exhaust throttle is adjusted, particularly with regard to the pressure drop across the exhaust throttle, so that a so-called supercritical flow of the gas through the exhaust throttle results
Data Source
Figure 1~2
Figure 3
Figure 4a
AI summary
The invention relates to a gas-powered drive system, comprising a drive (A) with a first chamber (1) and a second chamber (2), which are separated from one another by a movable work element (3) of the drive (A), in particular by a piston (3), wherein one chamber (1) of the two chambers (1, 2) can be connected to a gas source (4) to form a chamber (1) driving the work element (3), and the other chamber (2) of the two chambers (1, 2) can be connected at the same time via an exhaust air throttle (5) to a gas sink (6), in particular by means of a switchover valve (7), to form a chamber counteracting the movement of the work element (3), wherein a control valve (8) is assigned to the driving chamber (1), through which control valve the driving chamber (2) can be filled with gas from the gas source (4), wherein the opening cross-section of the control valve (8) can be adjusted depending on a control pressure prevailing upstream of the exhaust air throttle (5) in the flow direction or a control pressure dropping across the exhaust air throttle (5), wherein by means of the control valve (8) the opening cross-section can be made larger when, as the control pressure falls, it falls below a first threshold pressure and the opening cross-section can be made smaller, in particular the control valve (8) can be closed, when, as the control pressure falls further, it falls below a second threshold pressure. The invention also relates to a method for operating a gas-powered drive system.