Study On Chatter Stability Of Ring Gear Turning Process

Cutting chatter is almost present in all metal cutting processes and it is the main obstacle to improve the cutting efficiency. In this paper, processing of the typical high precision and weak stiffness of the ring gear is studied aiming to gain the condition of stable cutting without chatter. The main contents include the following aspects:Firstly, the 3D simulation of the cutting process of 20Cr2Ni4 A material ring gear is carried out by using the finite element simulation software ABAQUS. In order to make the simulation reliable, the thermo mechanical coupling of the cutting process is considered. So the cutting force we finally get is with higher credibility. Then the cutting force coefficient of unit area of the 20Cr2Ni4A material is calculated to establish the instantaneous cutting force.Secondly, by hammer test, the modal parameters of tool-machine system and workpiece-machine system including first-order natural frequency and equivalent stiffness and damping ratio are obtained by using Single Input Single Output method and orthogonal polynomial fitting method.Thirdly, machining chatter mechanism and the dynamic system of the ring gear cutting process are analyzed. Then the two degrees of freedom second order linear differential equations is established to describe the cutting system and in the frequency domain equation is solved. By using MATLAB software the relationship between spindle speed, and cutting width is shown in the cutting stability lobe diagram.Finally, according to the cutting stability lobe diagram, machining parameters are selected and turned into cutting test in order to verify the correctness of the model. In the end Stable region of ring gear cutting is identified.