The use of innovative solutions improving selected energy or environmental indices of hydrostatic drives

This paper consists of three parts. The first part presents an exemplary application of a state-of-the-art proportional directional valve in hydrostatic gear starting. It is shown that through a proper directional valve control algorithm one can shape the pressure during the starting of the gear, reducing in this way the accompanying system noise. The second part describes the digital fluid power (DFP) technology. Its main advantage is the system's simple design. One type of valve in 2 or 3 different sizes is sufficient to perform all the functions. In comparison with the often-used proportional valve, such a valve (called a binary valve), is characterized by simple circuitry, the absence of a position sensor, greater tolerance and lower sensitivity to impurities. An exemplary implementation of the DFP system as an additional drive in an off-road vehicle is presented. The third part describes the kinetostatic method for determining hydraulic system control parameters in order to increase the energy or environmental performance of the machine through the stabilization of the primary energy source and the selection of proper recuperation system components. (paper)