The Simulation And Analysis On Dynamics Characteristic For The Linear Motion Station Of Driven At Center Of Gravity

The processing quality and efficiency of production has seen the great leap accompanied with the development trend of high speed, efficiency and precision of workshop such as CNC in recent years. Dynamic performance requirements have been given more and more attention so as to improve the retention and reliability of machining accuracy. However, harmful factors such as different levels of vibration and noise can be created when the machine works under high speed and acceleration or some unconventional situation with big load and great displacement and so on. Research has shown that dynamic performance of the feed drive mechanism has significant impact on the processing quality and efficiency of CNC. In other words, dynamic performance of the feed drive mechanism is the key factor which can decide whether CNC machine can achieve a certain high level speed and precision.DCG (Drive at center of gravity, DCG) is a new and efficient feed-driven approach. This paper mainly focuses on the DCG which realizes its motion on the basis of a pair of lead screw, and deals with the influence trend of some key design parameters such as joint surface and structure of drive mechanism on dynamic performance, which can put forward theoretical reference for DCG system design method.The main contents of this paper are as following:(1) Figure out the research background, purpose and significance of DCG technology after referring and study the literature in relative field inside and outside the nation. Interpret this technology in detail, and what’s more, analysis how it realizes the drive as well as its advantage and disadvantage both inside and outside nation.(2) Establish the dynamic model of DCG, and the vibration differential equation is derived which figures out the response expression of six order natural frequency and position of each location. Put forward several principles in DCG design, and Steiner distance method is used to analysis the system structure. (3) In this paper, the two different methods are analyzed by dynamic test and virtual prototype simulation, and the vibration response whose drive system works in the condition of high and low-speed of DCG and traditional driving is contrasted and studied. Then, that the DCG can effectively inhibit the generation of vibration is verified, compared with traditional driving.(4) Build the parametric model of simplified DCG by using APDL language of ANSYS. First six-order natural frequency can be calculated out with considering the impact of joint surface between rail and slider on modal analysis. Set the factors that can greatly affect the dynamic performance as the key design parameters, and take the natural frequency as the indicator of the performance. Research the change trend of natural frequency under different design parameters.(5) Analysis transient dynamic and harmonic response of simplified model of DCG based on the modal analysis. Figure out the response situation under continued periodic load in structure system. Compare the vibration amplitude of gravity drive mechanism in X and Y direction under different structural parameters. Research influence law that how the stiffness parameter of joint surface between rail and slider affects the dynamic performance with other parameters keeping unchanged, which can provide theoretical basis for enhancement of dynamic performance of the drive system.