Summary: | The objective of this research was an in-depth analysis of energy losses in hydraulic systems. Energy losses were analysed on the basis of the leakage in the annular gap between the spool of hydraulic directional control valves and the hole channel. The impact of various annular gap heights during the different pressure conditions was investigated for two hydraulic fluids with different viscosities: tap water and ISO VG 46 mineral oil. The results were obtained using analytical, simulation and experimental methods. The results of leakage show good agreement between these three approaches. It was shown that grooves with an unusually larger gap (100 µm) led to less leakage in the case of the hydraulic fluid with the lower viscosity. Although the presence of a groove in combination with standard, small gaps (in classic hydraulic systems: 1 µm–5 µm) leads to greater leakage, the grooves are important to reduce the contact pressure along the sealing side of the spool, friction and wear.
|