Structural Optimization And Dynamic Analysis On A/C Biaxial Rotary Cnc Universal Milling Head

High-end CNC machine tools are the basis of manufacturing industry, for instance, five-axis CNC machine tools are powerful in the machining process of complicated, non-standard, and high-precision parts, that is why they have great influence on aerospace, shipbuilding, precision equipment and power generation industry.As the key assembly of five-axis CNC machine tools, biaxial rotary milling head composed of many parts, so it is complex in structure, difficult in ensuring the stiffness and hard to drive or control. In this paper, the work of precision design and analysis of static-dynamic characteristics for A/C biaxial rotary milling head is carried out, based on the modern precision design theory and Finite Element Method.Firstly, presented the overall design of A/C biaxial rotary milling head, demonstrated the control scheme of it, given the precision guarantee program, listed the follow-up work of mechanical design and the accuracy targets needed to achieve.Secondly, carried out the precision design for A-axis and C-axis drive system. Introduced the basic theory of precision design and discussed of the error synthesis method; allocated the transmission ratio, according to the angular error estimate method; derived A-axis and C axis error formula after discussing of the transmission error and return error calculation method in transmission chain, selected the accuracy class of gear and carried out accuracy calibration according to the indicators of point positioning accuracy and repeatability of positioning accuracy.Thirdly, created 3D solid models in SolidWorks based on engineering drawings, then imported them into ANSYS to generate the finite element model, discussed model simplification strategy and meshing strategies; calculated out the milling force, which was used as part of loading conditions in static structural analysis, according to actual milling parameters; discussed the results of static analysis.Finally, launched the dynamic characteristic analysis, to explore milling head's properties when working in dynamic load and thermal load environment for long-time. Introduced the basic theory of modal analysis, given the treatment of boundary conditions and the milling approach load, practiced the structure modal analysis, discussed the results of modal analysis and its impact on the structure properties; introduced the basic theory of thermal analysis, given the thermal load, boundary conditions and thermal-structural coupled analysis strategy, discussed the results of thermal analysis and its impact on the structure properties.