Reserch On The Main Drive System And Optimal Design Of Spindle Span In Machine Tool

As one of the most important components of machine tool,the function of spindle assembly is to drive the workpiece or tool during machining,so its performance will directly affects the machine's processing accuracy,surface quality and productivity.In order to solve some key problems on the design of main driving system and optimization of spindle span in development of CNC machine tool spindle design and analysis tool set,the dissertation investigated the design specification of main driving system.Based on the finite element analysis model of spindle-bearing system,the spindle span is optimized by means of simulation and experimental verification.Finally,a digital design software of spindle is implemented by integrating the above studied fruits into the CNC machine tool spindle design and analysis tool set with Visual C ++.Firstly,design of main driving system and development of corresponding software are carried out.Calculation of transmission on stepped transmission and stepless transmission is conducted based on the basic principles to design main driving system in CNC machine tools.Then the design processes of main driving system are standardized and its software manual is given.Secondly,the optimal design of NC machine tool spindles span was studied based on finite element method(FEM).According to the theory on static stiffness calculations for spindle,stiffness analysis and calculation of ball bearings and the optimal analysis and calculation of spindle span and,a parameterized finite element model of spindle was established and a series of optimization were applied to design the lathe spindle by first order optimization algorithm and overall optimization algorithm in ANSYS,the optimal span curves of the lathe spindle under certain conditions were obtained.Finally,the spindle span optimization simulation analysis and experimental verification were achieved.The simplified lathe spindle finite element model was built by parametric modeling method,and was optimized by first-order optimization algorithm in ANSYS when setting the displacement of the front end of spindle as optimum objective.The curves of radial static stiffness variation with span progressed for spindle were obtained.Spindle's static stiffness in different span was acquired by applying a radial load to the front end of spindle and measuring the radial displacement of corresponding position.At last,the reliability of the parametric modeling was validated by comparing the spindle stiffness analysis curve and simulation curve.