Simulation And Static, Dynamic Characteristics Analysis Of Telescopic Rod Type Parallel Mechanism Of Two Degrees Of Freedom

Less degrees of freedom parallel mechanism has been widely studied,because it’s better than serial mechanism and six degrees of freedom parallel mechanism. Telescopic rod type parallel mechanism of two degrees of freedom is composed of a movement platform,a static platform and three branched chains. By changing the length of the telescopic rod,the moving platform can rotate an angle to X, Y axis,making the space plane rotation to the horizontal plane.It can enlarge the using range of the machine tool by these parallel mechanism when the machine tool is processing parts.In this paper, the following research of the parallel mechanism are that:First of all, using the screw theory to analysis the degree of the telescopic rod type parallel mechanism, its can realize around the X, Y axis rotation.Due to the telescopic rod is the important part of the agency, so the study of the structure form is necessary; We mainly study three kinds of the hydraulic type, the linear motor and the electric push rod. This paper selects the straight association-like electric push rod which is broader to use with the simple mechanism,and determines the size of the other components.Second, three-dimensional entity model of the parallel mechanism is built on the platform of Pro/E and is assembled according to the relationship of parts. It’s study of virtual simulation of the entity model that to check the interference between components, the dimension of the parallel workbench. It’s modify the model structure according to the results of the simulation. It’s determine the limits posture of parallel workbench by the result of motion simulation.Again, the structure statics model is established by using the finite element method to research its static characteristic. By using ANSYS software,we can get the deformation and stress distribution of each parts which the parallel workbench under the drilling load at different limit posture position. It can verify if it satisfies the requirement of the material strength and the material stiffness on the basis of the maximum deformation and the maximum stress. It can find out the weak links of the structure and provide theoretical support for the structure optimization.Finally, researching its dynamic, dynamics model is established by using the finite element method to obtain the corresponding dynamic parameters. Through the modal analysis in the first place, it can be obtained the natural frequency and vibration model at different limit position of the parallel mechanism and get the workbench vibration property under the natural frequency. Next, through the harmonic response analysis, it can be got the movement platform amplitude-frequency curves over a range of frequency. Through the study of amplitude-frequency curve, the parallel workbench should be avoided the frequency range70Hz and300-400Hz in the working process.