Erosion behavior and influence of solid particles in hydraulic spool valve without notches

Hydraulic spool valve without notches is used as a kind of important amplification component in hydraulic servo valve. Its static and dynamic properties have a significant impact on the performance of servo valve and hydraulic system. Under solid particles erosion in oil, the metering edges of spool valve were usually eroded and worn. This process was irreversible and induced serious control performance degradation of orifice and valve. In this paper, the erosive behavior and influence of solid particles in hydraulic spool valve without notches were investigated. By the surface microtopography measurement of the spool, erosion corners failure were present. The CFD simulation of solid-liquid two-phase flow was carried out by discrete phase model (DPM) to analyze the erosion failure. The migration route of the severe erosion region of hydraulic spool valve without notches was obtained and the mechanism of local erosion was revealed. An interesting phenomenon of erosion inflection point and face-back flow was found. The exact calculation method of the orifice area under erosion was discussed and put forward. This paper provides a reference for further study on the erosion damage and erosion resistance of hydraulic spool valve without notches.