Performance Evaluation of Variable Flow Axial Piston Pump with Displacement Control Valve in Steady State Conditions

In order to improve the efficiency of hydraulic circuits, it is necessary to change the displacement volume of the pump and its output flow based on the load on the actuator. The use of a displacement control valve next to a variable flow pump makes it possible for the pump output oil flow to adapt to the load on the hydraulic actuators. In this paper, first of all, the mathematical relationships governing the variable flow pump with the displacement control valve are presented. Then, in order to determine the variables of the hydraulic pump in steady-state conditions, the mathematical relations governing it are solved in three working positions of the pump displacement control valve. Also, the effect of the load on the hydraulic motor shaft and the cross-sectional area of the flow control valve between the pump and the motor on the circuit state variables was investigated. The appropriate closeness of the experimental results with the results of solving mathematical relations in steady-state conditions and different working conditions of the displacement control valve confirmed the correctness of the mathematical relations governing the hydraulic circuit including variable displacement pump with control valve and variable displacement motor.