A mathematical model of the axial piston pump controller on example of Hitachi HPV102GW-RH23A

Abstract

The purpose of the paper is to develop a mathematical model of the controller of the axial piston pump Hitachi HPV102GW-RH23A to determine the influence of controller parameters on pump output characteristics and carry out the mathematical modeling of controller operation. The mathematical model of the controller is developed. Its solution scheme in Matlab-Simulink is proposed. Displacements of the spool (x₁), servo piston (x₃) are determined as well as changes in the pressure from a large area of the servo piston (p₃) in time at a nominal pressure in the system and when p>p_nom. The dependence of the servo piston displacement (x₃) on the spool spring stiffness is obtained. The developed mathematical model of the controller allows to find out the causes of malfunctions in the operation of the adjustable axial piston pump. Thus, an increase in the stiffness of the spool 1 spring by 5000 N/m decreases the servo piston displacement and, consequently, the pump flow by 20%. This reduces the load of the basic machine engine and causes the loss of excavator performance as a whole. The increase in the total stiffness of the springs of spool 6 in comparison with the nameplate data can lead to an overload of the excavator engine up to its complete stop.