Vibration Analysis Of CJ190Z4 Machine Tool Spindle System

In the modern era,the level of the industry is still an important indicator to measure the overall strength of a country.Manufacturing industry has always occupied an extremely important part.At the same time,with the gradual improvement of scienC and technology,the automation level of manufacturing industry is getting higher and higher.Especially the development of the machine tool industry plays an important role in the development of the national manufacturing industry.With the continuous development of modern scienC and technology,the machine tools continue developing to speed up,high-precision direction,so the requirements of machine tool dynamics are also gradually increased,machine vibration and dynamics problems are increasingly prominent.The spindle system is an important part of a machine tool.The vibration characteristics of the spindle system directly affect the overall performanC and the machining accuracy of the machine tool.It is also one of the important indexes for judging the safety and reliability of a machine tool.Therefore,the spindle used for high-precision lathe requires not only high spindle speed,but also high precision rotation,small vibration.Therefore,it is neCssary to consider the dynamic characteristics when designing the spindle.Considered above problems,CJ190Z4 machine tool spindle system experimental model was studied for this thesis,this thesis mainly carried out the following aspects:(1)Solidworks three-dimensional software was used to establish a three-dimensional simulation model of the experimental model of the machine tool spindle,Then,the model was imported into the design range of ANSYS Workbench finite element analysis software,and the parametric modeling method was simplified.After some steps like simplifying the mesh,distributing the properties of the material to the unit,a simplified finite element model was eatablished,then got the first six-axis machine tool natural frequency and the corresponding vibration shape diagram,and critical speed of rotation.(2)In this thesis using the finite element analysis software to got the static analysis,modal analysis and harmonic response analysis of the spindle system.The static analysis of the spindle of the machine tool gives the static stiffness of the spindle,the dynamic and static deformation of the spindle under Crtain load and the stress-strain curve of the spindle system.Then the modal analysis,harmonic response analysis and critical speed analysis of the spindle of the machine tool were carried out.The critical speed was calculated by the theoretical formula and the dynamic analysis data of the machine tool spindle was supported and referenCd.(3)Based on the finite element method,the dynamic model of a ten-DOF machine tool spindle system was established.For the first time,the finite element equations of static deformation and dynamic balanC of machine tool based on Lagrange equation and elastic theory were established considering spindle system elasticity,bearing elasticity and side plate elasticity.The differential equations of motion of the spindle system were established.By solving the differential equation of vibration,the analytical solution of the model was obtained.Using numerical analysis and computer analysis software MATLAB to calculated the dynamic model of the natural frequency and the main vibration mode.Through the simulation analysis of MATLAB software,the amplitude-frequency characteristic curves of the spindle system under different parameters such as damping,stiffness,ecCntricity and mass of the spindle system were studied and analyzed.The dynamic characteristics of the vibration under elastic constraint were analyzed by the amplitude-frequency characteristic curve.Runge-Kutta algorithm was used to solve the spindle system time-domain waveform,axis trajectory and phase plane diagram,etc.,to analyze the vibration of the spindle system.(4)The vibration test signal was obtained through the experiment and the actual natural frequency,damping ratio and corresponding vibration mode of the spindle model of the machine tool were obtained.Then modal matrix checking,the experiment verifies the rationality of finite element simulation analysis were accomplished.The dynamic responses of the spindle system at different speeds were tested and the amplitude and acCleration of the spindle at different speeds were obtained.The correctness of the simulation model and the correctness of the simulation results were verified by comparing the experimental data with the simulation data.