The Static And Dynamic Analysis Of Ultra-High Speed Grinding Machine Tool

Ultra-high speed grinding(UHSG) is a key element in advanced manufacturing technology with advantages of high efficiency and high machining surface quality. The development of UHSG machine tool with excellent performance has become more and more important nowadays.Aiming at improving the static and dynamic ability of the UHSG machine tool we are now researching, the dynamic models of high-speed motorized spindle system and the whole machine structure were created by the combination of FEM methods and experimental tests. Based on the correct model, some analyses were carried out to evaluate the performance and weakness of the UHSG machine for further study.The main research works are as follows:(1) The finite element model of the spindle system was established by the use of Ansys software and verified with the static hammer test, finding that its 1st critical speed is higher than the maximum speed. The influences of structure parameters of the shaft, bearing preloads, material and size of the wheel on the critical speeds of the high-speed motorized spindle were analyzed. And the unbalance response increased with the decreasing of the dynamic balancing precision of the grinding wheel.(2) By the combination of FEM and EMA(experimental modal analysis), the stiffness of the spring damping unit, which is used to simulate the joint surface of the grinding machine, was identified, being the foundation for the dynamic analysis of the UHSG machine.(3) The dynamic model of whole machine structure was created with the combination of FEM and EMA methods. Based on the modal analysis, the weakness of the UHSG machine tool were found in the joint surface of column and the support of worktable, and modified through structural developments and surface parameter adjustments to improve its dynamic characteristics.