Research Of Spring-and-Siaphragm Actuators And Optimal Design Of Spring

As the pneumatic actuator has the ability of explosion-proof,clean and safe,so it has been widely used in the process of petroleum,chemical and other industries.The main content of this subject is to study the actuator of the vertical stroke and to optimize the design of spring,which is used in diaphragm actuator.The function and structure of spring-and-diaphragm actuator are described in this paper.In view of the whole structure of the control valve,establish the dynamic equation.The transfer function is derived and the initial compression state of the spring is calculated.Using the Simulink to establish the simulation model,analysis the dynamic characteristics of the actuator.Analyses of the structure of the rolling rubber diaphragm,according to the strength of the rolling diaphragm formula,calculate the effective area of the diaphragm.According to the structure,the operating conditions,control parameters and other requirements,analysis of the balance of the valve body;according to specified ANSI class shutoff rating of the control valve,determine the seat load of the shut off force.The force balance equation of the pneumatic film actuator is established,and the stiffness range of the compression spring is deduced.MATLAB nonlinear optimization method is used to optimize the geometry of the spring.The spring 3D mould is established according to the optimized design.A finite element method is used to analyze the static stress distribution map of the spring,and to predict the occurrence of damage.In addition,the fatigue of the spring has been analyzed.According to the stiffness of the spring optimized design,the output pressure of the spring in the valve closing state is calculated.Determine the maximum load of the valve stem,in accordance with the material and geometric dimensions of the valve stem,to do the strength check and analysis.Finally to conform the valve stem will not be in the phenomenon of bending and instability.