Prediction and Improvement of Steady-State Performance of a Power Controlled Axial Piston Pump

This paper deals with the static and dynamic behavior of a variable displacement bent axis axial piston pump with power control. A mathematical model is deduced to predict the performance of the pump and its controller. The pump static and dynamic characteristics are also evaluated experimentally. A good agreement between the experimental and theoretical results is obtained which validates the deduced pump model. A redesign of the original pump controller is carried out, in order to produce constant output power (hyperbolic P-Q relation). The proposed controller includes a hydraulic accumulator used as a gas spring. A mathematical model for the pump, equipped with the proposed controller, is developed and used for the computer simulation. The effect of the proposed controller parameters on the pump performance is studied. The proposed controller produced a P-Q relation too close to the required hyperbola. In the dynamic mode of operation, the transient pressure oscillations and settling time are considerably reduced, but the maximum over shoot is increased.