STATIC STIFFNESS RESEARCH AND OPTIMIZATION ON A HYBRID MACHINE TOOL CONSIDERING THE STIFFNESSES OF BEARINGS AND GUIDEWAYS

The finite element analysis (FEA) model of a new type of heavy hybrid machine tool is built considering the stiff- nesses of bearings and guideways.The deformation of the ma- chine tool under the rated loads is computed.The static stiff- nesses of the machine tool are derived and compared with the results of the static stiffness experiment.Due to the little dif- ference between them,the simulation results are considered to be reliable.In order to improve the static stiffnesses of the ma- chine tool,the bearings with better stiffnesses are chosen and preloaded more than before.The simulation results indicate that the static stiffnesses of the machine tool become better after the optimization.