Análise de viabilidade técnica de uma bomba hidráulica compacta de deslocamento positivo, de pistão axial de dupla ação, acionada por tomada de força de um trator

Abstract

Hydraulic pumps assign energy to the fluid to transport it by flow from one point to another, converting mechanical work into energy for operation. Among the existing types of pumps, positive displacement piston pumps operate with low flow and high pressures, with the fluid displaced from suction to discharge in defined and continuous volumes. The use of these pumps presents the possibility of working with viscous fluids and with suspended particles, either in pressurization or atomization services according to the working fluid. The use of this type of pump in remote locations presents restrictions due to the size of the equipment and its peripherals, the type of drive and even its mechanical complexity regarding maintenance. The development of a prototype that can be used in situations of scarcity of resources and activated by the tractor itself encourages the possibility of saving time for certain agricultural tasks, as well as the practicality of using simple maintenance and handling equipment. This study aims to explore the technical feasibility of a positive displacement hydraulic pump, with a double-acting axial piston, driven by the power take-off of tractors of various types. The prototype under analysis has the advantage of a reduced size and high working pressure, ideal for spraying crops and transporting fluids between short distances, without using electricity. The pump casing was subjected to a computer simulation using the Finite Element Method (FEM), which showed stress concentrating points along the working body and other aspects related to safety factors, torsion in the casing and others. The prototype was tested at constant speed of 150 rpm, and also at constant speed of 300 rpm, presenting approximately 87 bar of working pressure before breaking off. The cracks found on the carcass during the failure analysis contributed with the computer simulation by the FEM, proving to be a reliable analysis. The prototype operating equations showed values for the average flow rate Q = 0.00029134 m³ / s, specific energy supplied to the liquid Y = 22155.878 J / kg and pressure drop in the valves 𝑯𝒂 = 0.9822 mca. Based on the information analyzed throughout this study from drawings, calculations and simulations, the developed prototype is technically feasible for agricultural applications since it presents reduced dimensions, adequate pressure and flow, and also simple mechanical requirements.