Comparison of leakage level in water and oil hydraulics

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.

[1]  Ke Jian,et al.  Research on the lubrication characteristics of water hydraulic slipper friction pairs , 2006 .

[2]  Yoshiharu Inaguma,et al.  A practical approach for analysis of leakage flow characteristics in hydraulic pumps , 2013 .

[3]  Holger Löwe,et al.  Chemical micro process engineering : fundamentals, modelling and reactions , 2005 .

[4]  G. Vaidyanathan,et al.  Pressure drop and cavitation investigations on static helical-grooved square, triangular and curved cavity liquid labyrinth seals , 2011 .

[5]  Sushil Kumar,et al.  The effect of piston grooves performance in an axial piston pumps via CFD analysis , 2013 .

[6]  Deyou Li,et al.  Influence of clearance parameters on the rotor dynamic character of hydraulic turbine shaft system , 2014 .

[7]  Ugur Yücel.  Calculation of leakage and dynamic coefficients of stepped labyrinth gas seals , 2004, Appl. Math. Comput..

[8]  Ting Rui,et al.  A time–frequency analysis based internal leakage detection method for hydraulic actuators , 2016 .

[9]  K. Jacobs.  Introduction to Microfluidics. By Patrick Tabeling. , 2006 .

[10]  Liu Shuyin,et al.  Simulation and experiment on the flow field in fit clearance for a large size spool valve , 2011, Proceedings of 2011 International Conference on Fluid Power and Mechatronics.

[11]  J. Watton,et al.  Axial piston pump grooved slipper analysis by CFD simulation of three-dimensional NVS equation in cylindrical coordinates , 2009 .

[12]  Volker Hessel,et al.  Chemical micro process engineering , 2003 .

[13]  Himadri Chattopadhyay,et al.  Analysis of flow structure inside a spool type pressure regulating valve , 2012 .

[14]  H. Laborit,et al.  [Experimental study]. , 1958, Bulletin mensuel - Societe de medecine militaire francaise.

[15]  Dušan Gordić,et al.  Spool valve leakage behaviour , 2011 .

[16]  Riccardo Amirante,et al.  Flow forces analysis of an open center hydraulic directional control valve sliding spool , 2006 .

[17]  Xing-Dong Li,et al.  Effects of groove shape of notch on the flow characteristics of spool valve , 2014 .

[18]  J. Y. Kazakia,et al.  Air flow in cavities of labyrinth seals , 1995 .

[19]  S. P. Asok,et al.  Neural network and CFD-based optimisation of square cavity and curved cavity static labyrinth seals , 2007 .

[20]  J. Watton,et al.  A complete analysis of axial piston pump leakage and output flow ripples , 2012 .

[21]  S. H. Hong,et al.  A new type groove for hydraulic spool valve , 2016 .

[22]  Weizhe Wang,et al.  Numerical Analysis of Leakage Flow Through Two Labyrinth Seals , 2007 .

[23]  H. A. El-Gamal,et al.  Leakage from labyrinth seals under stationary and rotating conditions , 1996 .

[24]  Nirmal K. Manna,et al.  Study of leakage flow through a spool valve under blocked-actuator port condition—Simulation and experiment , 2014 .

[25]  Xudong Pan,et al.  Flow field simulation and a flow model of servo-valve spool valve orifice , 2011 .

[26]  Thomas Pütz,et al.  Reduced order model for estimation of fluid flow and flow forces in hydraulic proportional valves , 2008 .

[27]  Huan Liu,et al.  Numerical simulation of flow characteristics for a labyrinth passage in a pressure valve , 2016 .