Introduction
⌅Hydraulics is one of the most versatile and flexible forms of energy transmission invented by humans (Dransfield, 1981DRANSFIELD, P.: Hydraulic control systems-design and analysis of their dynamics, Ed. Springer, 1981.). Hydraulic systems simply convert energy from one form to another to perform work. In heavy machinery, this translates into using the energy provided by the internal combustion engine, commonly known as diesel engines, into hydraulic power (Guasumba et al., 2021GUASUMBA, M.J.E.; GARAY, C.V.A.; SOLÍS, S.J.M.; JIMA, M.J.C.: “Análisis del sistema de inyección electrónica de combustible para motor de combustión interna respecto a sus fallas y mantenimiento”, Polo del Conocimiento, 6(1): 603-621, 2021, ISSN: 2550-682X.).
The hydraulic pump is a mechanical system that is part of a hydraulic system that commonly exists today (Llanes et al., 2020LLANES, C.E.A.; MORENO, P.A.; GUAÑA, F.W.V.; JIMA, M.J.C.: “Análisis estructural de un bus por el método de elementos finitos”, 2020, ISSN: 2550-682X.). The pump's movement involves regulation and control actions to increase a flow rate (Manring and Fales, 2019MANRING, N.D.; FALES, R.C.: Hydraulic control systems, Ed. John Wiley & Sons, 2019, ISBN: 1-119-41647-7.).
The gear pump has a positive displacement, meaning its flow rate is determined by revolutions, but this cannot be varied (Tipán et al., 2021TIPÁN, S.A.M.; BELTRAN, C.C.M.; JIMA, M.J.C.; GUASUMBA, M.J.E.; VEGA, S.W.H.: “Análisis del rendimiento de las bombas hidráulicas de máquinas autopropulsadas dedicadas a movimiento de tierras”, Polo del Conocimiento, 6(3): 1570-1580, 2021, ISSN: 2550-682X.). The fluid is transported between the gear teeth and the casing, the meshing gears fitted to the casing (Paneque, 2010PANEQUE, R.P.: Elementos y Sistemas Oleohidráulicos en las Máquinas Agrícolas, Ed. Universidad Autónoma Chapingo, primera ed., vol. 1, Universidad Autónoma Chapingo, Departamento de Ingeniería Mecánica Agrícola, Chapingo, Texcoco, Edo. México, 285 p., 2010, ISBN: 978-959-16-2382-9.). This type of pump operates at non-regulated high speeds and low pressures and is made of a cast iron or aluminum alloy casing (Merritt, 1967MERRITT, C.: “Systems Approach to Pipe Handling, Cementing, and Mud Mixing”, En: Annual Meeting of the American Institute of Mining, Metallurgical, and Petroleum Engineers, Ed. SPE, p. SPE-1729, 1967, ISBN: 1-55563-841-4.).
The performance of a hydraulic pump is determined by the output pressure, the flow rate at which it operates, its displacement relative to the flow rate, its driving torque, and its angular velocity.
The absence of suction and discharge valves results in the existence of spaces in hydraulic machines between the fixed and moving walls, where the main energy losses occur (Paneque et al., 2018PANEQUE, R.P.; LÓPEZ, C.G.; MAYANS, C.P.; MUÑOZ, G.F.; GAYTÁN, R.J.G.; ROMANTCHIK, K.E.: Fundamentos Teóricos y Análisis de Máquinas Agrícolas, Ed. Universidad Autónoma Chapingo, vol. 1, Chapingo, Texcoco, México, 456 p., 2018, ISBN: 978-607-12-0532-2.; Yao, 2018YAO, J.: “Model-based nonlinear control of hydraulic servo systems: Challenges, developments and perspectives”, Frontiers of Mechanical Engineering, 13: 179-210, 2018, ISSN: 2095-0233.; Merritt, 1967MERRITT, C.: “Systems Approach to Pipe Handling, Cementing, and Mud Mixing”, En: Annual Meeting of the American Institute of Mining, Metallurgical, and Petroleum Engineers, Ed. SPE, p. SPE-1729, 1967, ISBN: 1-55563-841-4.; Kong et al., 2022KONG, X.; CAI, B.; LIU, Y.; ZHU, H.; LIU, Y.; SHAO, H.; YANG, C.; LI, H.; MO, T.: “Optimal sensor placement methodology of hydraulic control system for fault diagnosis”, Mechanical Systems and Signal Processing, 174: 109069, 2022, ISSN: 0888-3270.). The operating speed of a hydraulic machine is determined by the following three parameters: pressure difference or gradient, rotor rotational angular velocity, and the dynamic viscosity coefficient of the fluid (Merritt, 1967MERRITT, C.: “Systems Approach to Pipe Handling, Cementing, and Mud Mixing”, En: Annual Meeting of the American Institute of Mining, Metallurgical, and Petroleum Engineers, Ed. SPE, p. SPE-1729, 1967, ISBN: 1-55563-841-4.; Nekrasov, 1968aNEKRASOV, B.: Hidráulica, Ed. Mir, Moscú, Rusia, Moscú, Rusia, Publisher: MOSCÚ: MIR, 1968a.; 1968bNEKRASOV, B.: Hidráulica, Ed. Instituto cubano del libro, La Habana, Cuba, vol. 1, La Habana, Cuba, 976 p., 1968b.; Paneque, 2010PANEQUE, R.P.: Elementos y Sistemas Oleohidráulicos en las Máquinas Agrícolas, Ed. Universidad Autónoma Chapingo, primera ed., vol. 1, Universidad Autónoma Chapingo, Departamento de Ingeniería Mecánica Agrícola, Chapingo, Texcoco, Edo. México, 285 p., 2010, ISBN: 978-959-16-2382-9.).
The efficiencies of rotary hydraulic machines are simply expressed by the isogonality coefficient and the leakage coefficients of fluid friction losses and dry friction losses (Pérez and Paneque, 2001PÉREZ, S.; PANEQUE, P.: “Parámetros de rendimiento de una bomba oleohidráulica”, Revista Ciencias Técnicas Agropecuarias, 10(1): 37-40, 2001.).
Taking into account the above, the present work aims to develop an automated system for the theoretical determination of the operating parameters of hydraulic machines (pumps and motors).
Materials and methods
⌅Based on the theoretical research developed by Pérez et al. (2005)PÉREZ, S.L.; PANEQUE, R.P.; DE LAS CUEVAS, M.H.: “Fundamentación de los parámetros de funcionamiento de la máquina hidráulica rotatoria”, Revista Ciencias Técnicas Agropecuarias, 14(1): 19-22, 2005, ISSN: 1010-2760., as well as experimental and statistical data on the operating parameters of hydraulic machines, the automated Performance Curves version 2.0 system was developed using the Excel platform of Microsoft Office Professional Plus 2021.
This automated system (Performance Curves) is used to determine the operating parameters of rotating hydraulic machines. The software was developed based on the synthesized flow diagram shown in Figure 1.
Upon entering the system, you directly access the Control Panel, which includes the selection of the machine (pumps or motors), selection of the machine status (normal or abnormal), selection of the coefficients (normal or abnormal), results (table and graph) and About: (Figure 2).
The machine status selection window contains the following:
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Normal or Abnormal: Allows you to enter data on the machine's status (normal or abnormal) using a radio button.
These windows have command buttons that facilitate returning to the Control Panel, the results table, and the efficiency graph for the selected conditions (Figures 3 and 4).
- The results window contains the following buttons:
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Table: Accesses the results window for the isogonality coefficient, volumetric efficiency, mechanical efficiency, and total efficiency for a range of pressures preset by the user. It also determines the value of the isogonality coefficient* and the maximum total efficiency of the hydraulic machine.
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This window has command buttons that allow you to return to the Control Panel and the efficiency graph for the selected conditions.
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Graph: Displays the volumetric, total, and mechanical efficiency curves as a function of the isogonality coefficient, allowing you to study their behavior for a hydraulic machine under different wear conditions, resulting from contamination and operation (Figure 5).
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This window has command buttons that allow you to return to the Control Panel and the results table.
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About: Window showing the authors' names, version, logo, and work center address, etc.
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Conclusions
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The automated "Performance Curves" system is easy to use, allowing access to each component via the user's link to the Main Control Panel.
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Performance Curves allows for the accurate and reliable determination of the operating parameters of hydraulic machines (pumps and motors).
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The software allows for determining the maximum total efficiency of hydraulic pumps and motors.