Modelling and Experimental Verification of the Interaction in a Hydraulic Directional Control Valve Spool Pair

Abstract

This study examined the impact of mechanical oscillation on a hydraulic directional control valve. Particular attention was paid to the oscillating movement of the spool of the hydraulic directional control valve resulting from this impact. Different models of fluid and mixed friction were considered. The models analysed accounted for the relative movement of the directional control valve body and the fact that it is kinematically excited by external mechanical oscillations. It was observed that the mixed friction model, where the frictional force is considered to be the sum of molecular forces acting in micro-areas of contact and drag forces in the fluid, was the best for describing the movement of the spool for a specific spool oscillation frequency. This model yielded significantly more consistency between the simulated and experimental results than the classic fluid friction model.

The Impact of Mechanical Vibrations on Hydraulic Valves and the Possibility of Reducing the Effects

“…Since the valve control element (e.g., spool) vibrates, the area of the valve's throttling gap changes, which in the hydraulic system is manifested by pulsation of performance and, consequently, of pressure, with the components of the spectrum of this pulsation corresponding to the components of the vibration spectrum of the excited element. Our investigations and literature studies (Wang et al, 2021;Josifovic et al, 2016;Stosiak et al, 2023) show that the resonant frequencies of hydraulic valve control elements (conical poppets, spools) are below 100 Hz (Stosiak et al, 2023). The range of these frequencies is also particularly dangerous for humans since the resonant frequencies of vital internal organs are also below 100 Hz (Zheng et al, 2019;Arnold et al, 2018;Govindan et al, 2020).…”

The Preparation, Microstructure, and Wet Wear Properties of an Fe55-Based Welding Layer with the Co-Addition of 0.01 wt% CeO2 and 1.5 wt% SiC Particles Using the Plasma Beam Spraying Method

“…The size of the abrasive debris was significantly different. Part of the abrasive debris was newly generated, which indicated that not only abrasive wear but also three-body wear had occurred during wet friction [22]. The end point of partial furrows was visible (the red dashed line) in Figure 10f, which was the result of the abrasive SiC being blocked by the Cr 7 C 3 hard phase and being unable to deflect to the nearby area.…”

Research Status, Existing Problems, and the Prospect of New Methods of Determining the Lower Limit of the Physical Properties of Tight Sandstone Reservoirs

“…The formation and presence of water films are the result of complex physical and chemical processes between solids and liquids. The water-film thickness is not a fixed value and is affected by many factors such as temperature, pressure, minerals, curvature, and formation water [57]: (1) regarding the effect of temperature, a higher temperature is associated with more intense molecular thermal motion, leading to a smaller water-film thickness. ( 2) Regarding the effect of formation pressure, Wang, W.M.…”