三级电液伺服阀零位高频自激振荡机理分析

Analysis of null high-frequency free-running oscillation of 3-stage electro-hydraulic servo valve

通过对三级电液伺服阀的建模和仿真分析,揭示了三级电液伺服阀零位高频自激振荡现象的本质,即该现象是因小球由线性环节变化为磨损后的非线性环节并产生了极限环振荡而造成的。通过计算分析给出了极限环振荡的幅值、频率与小球磨损量之间的关系。

Null high-frequency free-running oscillation will gradually come forth in the 3-stage electro- hydraulic servo valve after being used for a certain time period. The trouble, when it develops to a certain degree, will directly interfere with normal operation of hydraulic control system. This paper has modeled and simulated the 3-stage electro-hydraulic servo valve, and revealed that the null high- frequency free-running oscillation of the 3-stage electro-hydraulic servo valve is essentially due to the ultimate circular oscillation of the spherules which have turned into a non-linear gap segment from a linear one. Finally, the relationships between the amplitude, the frequency of the ultimate circular os- cillation and the abrasion of the spherules have been obtained from computation and analysis. The understanding of the phenomenon is beneficial to the maintenance, use and reliability design of the 3- stage electro-hydraulic servo valve.