The Researching Of The Key Technology About Five Axis Vertical Machining Center’s Trunnion Type Rotary Turntable

With the rapid development of science and technology, CNC machine tools is gradually developing toward high speed, high precision, high efficiency and compound.Five axis vertical machining center is one of the key direction of development.Five axis CNC machine has many advantages, such as high degree of automation, flexibility and high machining accuracy, and have been widely used in machining complex surface and complex parts.Machining center can implement complex parts clamping at one time, at the same time, use a variety of processing methods for complex curved surface, so it is widely used in aerospace, national defense, and other important areas. And high precision NC worktable is an important part of a five axis machining center, is the key to realize five axis machining, so it has been received the attention of many countries and is a hot issue in the research field at present.In this paper, through computer modeling and simulation technology, the 3D modeling of the key components in the five axis vertical machining center has been built.To provide the important reference for structure optimization, static and dynamic performance,simulation and comprehensive analysis are done.Working content is as follows:(1) The whole structure of the NC rotary table is designed, the roller gear cam is selected as the key transmission components.And though the kinematics analysis, the angle of A and C shaft and the movement distance of X, Y, Z three straight axis are calculated. Though the dynamic analysis, velocity coupling, coupling torque and rotational inertia coupling formula are calculated.These are the basis for selecting the motor and bearings.The key components (such as roller-gear cam, gears and hydraulic braking device) are designed.And finally a 3D model is created.Because the working face of the roller-gear cam can not be expanded,surface equation in Pro/e is used to create the model.(2) The statics analysis on key components of rotary table.We carry on the FEA analysis and calculation on the mechanism model of transmission components that is established as a whole, including analysis of the contact force in different engaging position between the cam and the roller, and in the process of transmission of stress and deformation of the pin shaft.(3) The modal analysis on key components of rotary table. The first five nature frequencies and modes are given. And the critical rotational speeds of roller-gear cam shaft and turntable are given to avoid resonance and ensure good dynamic performance.(4) The kinematics analysis on rotary table.We give the kinematic analysis of NC rotary table mechanism by using the mechanical system dynamic simulation analysis software ADAMS. The kinematics performance of the mechanism can satisfy the working condition. The feasibility and stability of the NC rotary table can be verified.