The Static And Dynamic Analysis Of The Machine Tool' Spindle System And Its Optimization

Modern CNC machine integrated application of the latest results of mechanical design and manufacturing technology, computer and automatic control technology and so on, is developing towards high-speed, high-accuracy, complex, flexibility and so on. The static and dynamic deformation of the machine tool spindle system is the main reason which affects the machining accuracy. Utilizing the finite element analysis software into the designing machine tool will reduce a lot of work and improve the product.In this paper, the spindle system is studied by using ANSYS software. Details of studies are show as follows.(1) By modeling and studying contact characteristics of Angular Contact ball bearing in ANSYS, the displacements and the stiffness curve of the rolling of the bearing under different loads are plotted, comparing the results with the results calculated by Herz algorithm. Draw the curves which describe the relationship of the bearing stiffness and bearing preload.(2) The three-dimensional finite element model of the spindle system is established and with the combin14 element instead of the bearing, get the static stiffness of the spindle by static analysis of the spindle system.(3) Analyze the dynamics character of the spindle system, including modal analysis and harmonic analysis, four order spindle natural frequency is got in the modal analysis and calculated the critical speed. In harmonic analysis, a curve which describes the displacement of different points of the spindle changes with the frequency is got.(4) To optimize the design of the spindle. Establish the parameterized model of the spindle, To optimize the spindle with the volume of the spindle objective function, the length and the radius of the spindle design variables, the static deformation and the first order natural frequency state variables, Aiming at the spindle has a lightest structure and with good static and dynamic performance.