Characteristics of the stationary behaviour of water- and oil-based power-control hydraulics
Keywords:distilled water, mineral oil, hydraulics, proportional directional valve, stationary characteristics
AbstractIn this paper we demonstrate with stationary pa-rameters the functionality of water hydraulics in compari-son to the usual oil hydraulics. The movements of the wa-ter hydraulics’ cylinder rod differed from the movements of the oil hydraulic cylinder by 2 to 6%. The pressures required to start the movement of the cylinder rod were up to 21% higher in the water hydraulics than in the oil hy-draulics. The working pressures required to move the cyl-inder rod with a constant velocity were 20 bar higher in the water hydraulics than in similar oil hydraulics. The great advantage of water hydraulics is the clear 45% to 65% lower pressure losses than in the oil hydraulic. The last stationary parameter that we evaluated was the time delay of the movement of the hydraulic cylinder rod. In water hydraulics this delay was 2 to 5 ms longer than in oil hydraulics.
MECHANICS OF FLUIDS AND GASES