Steady State and Dynamic Characteristics of Water Hydraulic Valves for Mining Robot
Laine, Anton (2022)
2022
Konetekniikan DI-ohjelma - Master's Programme in Mechanical Engineering
Tekniikan ja luonnontieteiden tiedekunta - Faculty of Engineering and Natural Sciences
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Hyväksymispäivämäärä
2022-10-19
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202209277307
https://urn.fi/URN:NBN:fi:tuni-202209277307
Tiivistelmä
This master’s thesis was done on the mechatronics research group of Tampere University. The thesis is related to the robominers project in which a completely new water hydraulic mining robot is developed. The objectives of the thesis were to determine the maximum control frequency of two different water hydraulic on-off valves and to study the response of a water hydraulic pressure-reducing valve. To find answers to the research questions measurements were conducted in laboratory with three different test systems. One of the tested on-off valves was direct operated and the other tested valve was pilot operated. As expected according to the literature the maximum control frequency of the direct operated valve was higher than the maximum control frequency of the pilot operated valve. With the maximum on-off valve control frequencies determined in this thesis the actuators of the mining robot can be precisely controlled.
The pressure-reducing valve was constructed of two direct-operated on-off valves, pressure sensor and two accumulators. The purpose of the two accumulators were to dampen the pressure peaks. The pressure-reducing valve was tested with different flows when keeping the target pressure constant. The pressure-reducing valve was tested also with different target pressures when keeping the flow constant. According to the measurements the performance of the pressure-reducing valve was good with pressures of 40 bar or above, but the pressure-reducing valve had poor performance with pressures 30 bar or less. The measurements of this thesis prove that the operation principle of the pressure-reducing valve works in practice and according to the measurements the pressure-reducing valve can now be used on the mining robot where pressure is reduced to 40 bars.
The pressure-reducing valve was constructed of two direct-operated on-off valves, pressure sensor and two accumulators. The purpose of the two accumulators were to dampen the pressure peaks. The pressure-reducing valve was tested with different flows when keeping the target pressure constant. The pressure-reducing valve was tested also with different target pressures when keeping the flow constant. According to the measurements the performance of the pressure-reducing valve was good with pressures of 40 bar or above, but the pressure-reducing valve had poor performance with pressures 30 bar or less. The measurements of this thesis prove that the operation principle of the pressure-reducing valve works in practice and according to the measurements the pressure-reducing valve can now be used on the mining robot where pressure is reduced to 40 bars.