Study On Multi-field Coupling Vibration Characteristics Of Armature Assembly In A Hydraulic Servo Valve Torque Motor

For the servo valves which use the jet-flow components as the prestage, it is easy to produce self-excited high frequency noise, which seriously affects the performance of servo valves. The nonlinearity of the servo valve, the forced vibration of the armature assembly and the shear layer oscillation in the prestage are all the possible causes of high frequency noise. So the study on the vibration characteristics of armature assembly is of great importance for the discovery of the mechanism of self-excited noise.The vibration characteristics of armature assembly are studied by means of simulation and experiments. The mathematical model of the forces on the armature assembly is built. The basic theory and method of modal analysis and harmonic response analysis are carried out in detail. The finite element model of armature assembly under different installment ways are built based on ANSYS software. The natural vibration frequencies and corresponding vibration modes are calculated through modal analysis. The effects of the spool and the hydraulic spring on the results are analyzed. The harmonic response analysis of the armature assembly coupled with the electromagnetic field and the flow field is carried out based on the modal analysis method. The harmonic response curves of three key points are obtained and the regularity of the vibration energy distribution is analyzed. The effects of the load and the damping on the vibration characteristics are studied. To compare with the results of the simulation, the experiments of the static and dynamic response are performed by using a laser displacement sensor. The effectiveness of the finite element model is validated by error analysis.The results of this paper offer useful reference for the discovering of the mechanism of self-excited noise and the seeking of some effective restraining measures.