关键词: 四边滑阀, 冲蚀, 性能演化, 零偏, 惠斯通桥路

Abstract: In view of the profile changes of valve port and performance uncertainty of the high-end hydraulic components caused by erosion of the slide valves， considering the probability of particle hitting the valve port, the quantitative calculation method of the erosion fillet of full-circumference opening slide valve was established based on the Edwards erosion model. Combined with the valve-controlled symmetric cylinder systems, the evolution law of four portss profiles and the characteristics of the four-sided slide valve after erosions were obtained. The results show that the erosion fillets are directly determined by the particle size, amount, impact velocity, valve opening and so on. The greater the valve port flowrate, the greater the amount of particles, the greater the pressure drop, the greater the impact velocity. The larger the size of particles relative to the valve opening, the greater the probability of particle hitting valve port. In the valve-controlled cylinders power mechanism, the size, speed and load of the hydraulic cylinder determine the flowrate, pressure drop and opening of the valve ports. Under the conditions of constant load and consistent reciprocating speed of hydraulic cylinders, the flowrate of the four valve ports of the valve-controlled symmetric cylinder is the same but the pressure drop is different, the fillets after erosion are inconsistent. Erosion results in the decrease of the pressure gain and increase of leakage of the slide valve, and the null bias occurs, the null bias displacement may be obtained by the balance principle of Wheatstone bridge.

Key words: four-sided slide valve, erosion, performance evolution, null bias, Wheatstone bridge