Dynamic PerformanceAnalysis Of Machine Tool Feed Drive

Modern CNC is developing constantly in the direction of the high precision and highspeed, which makes it to challenging to guarantee manufacturing accuracy in heavy load.Therefore, it is significant to study CNC’s dynamic performance in operation state. TakingCNC milling machine as the research object, this thesis proposed a dynamical modelconcerning the complicated dynamic performance of movable joint interface. Theelectro-mechanical co-simulation, rigid-flexible couple and discrete feed system arecombined to establish a dynamic characteristic analysis platform to predict the dynamicperformance of CNC. Main contributions of this dissertation are shown as follows:Firstly, based on Hertz contact theory and the structural characteristics of feed systemmovable joint interface, the dynamic parameters of ball linear guide way, bearing and ballscrew were distinguished. The influences of pre-tightening force, centrifugal force andgyro torque were considered. The influence relation of speed and force to contactdeformation was obtained.Secondly, the structure of lead screw and guide rail were divided by the self-development module. Besides, the kinematic pairs were custom designed according to thedynamic performance of movable joint interface. Examples showed that the discrete feedsystem is more realistic comparing to the traditional joint model.Finally, a dynamic characteristics analysis platform for whole machine wasestablished, combining the rigid-flexible couple and electro-mechanical co-simulationtechniques. Dynamic error in the progress of triangular moving without load and millinground boss wave was analyzed. Comparing with traditional modeling method, thedynamic error obtained by new method was more reasonable. Influences of control system,structure elastic and movable joint interface to dynamic characteristics was discussed.According to the above research, a feasible method was proposed for buildinghigh-accuracy multi-body dynamics virtual prototyping and analyzing dynamicperformance of machine tools.