Dynamics of slow hydraulic units with recurrent cam and variable capacity

Abstract

The paper presents a study of slow hydraulic unit with radial pistons, two recurrent cams and variable capacity, designed in the frame of a research program in faculty. For this apparatus it was developed a mathematical model which was able to supply numerical analysis for transitory and permanent regime of such a device. For simulation it was used a mathematical model derived from experimentally tested physical model, for which it was assigned the permanent regime characteristics and it was compared to the theoretical diagrams. The mathematical model coefficients have cross-correlations with unit geometrical characteristics and with the hydraulic agent used into the driving system. The analysis provides useful information especially regarding the low rev regime when functional instability becomes very pronounced and the working state was limited at a stable minimum value. This research is very useful for designers of hydrostatic devices and equipments.