Design And Research Of The Two-Stage Electric Cylinder

The two-stage electric cylinder is a kind of industrial linear actuator, it can convert motor rotary motion into linear reciprocating motion of screw drive system. The electric cylinder has been widely used in agriculture, industrial, automatic line as well as national defense in a number of developed countries such as Europe and the United States. China's electric-cylinder product technology and research began rather late, is also mainly used in erecting the radar, inertial navigation technology, specialty vehicles and space simulation technology and other sophisticated research. Moreover, the current research and application of the electric cylinder mainly use single-stage drive. Many domestic scholars have also done a lot of research in the multi-stage electric cylinder. For some workplaces that require relatively larger stroke on the installation space constrained, the research and application of two-stage electric cylinder will have an important application value and theoretical significance.In the technical requirements of two-stage electric cylinder, the paper based on structural design is written towards research of the theory and characteristics, taking the research work as follows:(1)It presents a two-stage screw drive structure based on combining hollow screw and sliding spline by studying the present domestic and international electric linear actuator and designs overall transmission scheme;(2)The parameters of the screw drive system were designed through writing MATLAB program with MATLAB optimization toolbox and GA, SUMT optimum design method. The parameters design of synchronous belt transmission and assembly drawing of the two-stage electric cylinder were done as well;(3)Mechanical transmission system properties such as motion characteristic, deflection problem, transient impact properties, mechanical transmission precision properties, dynamic properties were studied and analyzed briefly according to the transmission structure scheme and parameters, which provides theory basis for further research of the two-stage electric cylinder;(4)The 3D components models and assembly model of the two-stage electric cylinder were built by using Pro/E. Then, the assembly model was imported into ADAMS through MECH/PRO program so as to build the multi-body dynamics model of the two-stage electric cylinder and study the kinematic properties. The results were consistent with obtained correlation characteristic theory and synthetic motion theory and confirmed the movement's rationality of the two-stage lead screw drive;(5)The modal analysis of the main screw and the static analysis of the rear cover based on the finite element method were done in the platform of ANSYS software so as to obtain natural frequencies and mode shapes of the main screw as well as the deformation results of the rear cover.The results showed that the main screw could avoid the vibration frequency from reciprocating work frequency of the two-stage electric cylinder so that the resonance could not occur on main screw and the back cover design and material selection meet the design functional requirements. After that, it simplified the structural model of two-stage electric cylinder at the maximum effective stroke and obtained the value of buckling load by buckling analysis, the results showed that the two-stage electric cylinder does not occur lateral bending instability within the design load requirements;(6)The servo control system scheme of the two-stage electric cylinder was described simply and the mathematical model was built. And, the paper obtained the transfer function of servo control system providing the basis for further design and research by using the signal flow diagram and Mason's gain formula.