Simulation Analysis of Wear Characteristics on Sealing Surfaces in High-Pressure and Large-Flow Hydraulic Directional Valves

In response to the problem of sealing failure caused by severe wear of the sealing surface of metal hard sealing directional valves under high pressure and large flow conditions, a simulation model for predicting the wear trend of the valve seat-spool sealing pair of the directional valve was established based on the Archard wear model and finite element analysis method. Based on the wear simulation model, the influence rules of material parameters, sealing surface quality, and load on the wear characteristics of the directional valve sealing surface were studied. The simulation results show that during the switching process, the wear on the valve seat contact surface is concentrated at the edge positions and diagonal areas, while the wear on the spool is concentrated at the positions on both sides of the orifice near the spool and at the edge positions. The load is directly proportional to the amount of wear; the worse the surface quality, the larger the friction coefficient and wear coefficient, and the higher the total wear amount. The amount of wear is mainly affected by the wear coefficient, which is a comprehensive parameter for measuring the wear characteristics of the sealing surface. Accurately measuring the wear coefficient of the sealing surface through experiments is key to achieving high-precision wear simulation. Titanium nitride and tungsten carbide coatings exhibit excellent wear resistance and can serve as a development direction for optimizing the surface treatment process of subsequent directional valve sealing surfaces.