Research On The Research Of Static And Dynamic Characteristics Of Milling-turning Compound Machining Center Of Motoirzed Spindle

As one kind of the compound machining technology, milling-turning compoundmachining requires high efficiency, and functions which can adjust to complexconditions, thus the spindle system of machine tool requires good static and dynamiccharacteristics. The performance of the milling-turning compound machining centersis largely determined by the structural design of the motorized spindle and static anddynamic characteristics, and which are also important factors to affect the machiningaccuracy. The optimization of spindle structure and the study of static and dynamiccharacteristics is strategically critical to improve the performance of themilling-turning compound machining centers.Some integrated factors of modeling and simulation of milling-turning compoundmotorized spindle are presented to study the static and dynamic characteristics of themotorized spindle in FEM based on the software ANSYS in this thesis. Specificdetails of the thesis are as follows:(1) The structural of the milling-turning compound motorized spindle is analyzed,the spindle span and the front bearing spacing are optimized by the establishment oftwo-dimensional model of motorized spindle, besides, the interference fit of the shaftand motor is calculated.(2) Static rigidity of angular contact ceramic ball bearings is calculated, and thevariation of static rigidity with the effect of the axial preload is studied. Also, moreaccurate three-dimensional solid model of the milling-turning compound motorizedspindle is established, the static rigidity of motorized spindle is calculated by staticfinite element analysis based on ANSYS, and the effect of bearing preload on thestatic rigidity of motorized spindle is analyzed.(3) Through dynamic finite element model, the critical speed of themilling-turning compound motorized spindle is obtained by using ANSYScomputational analysis. The natural frequencies and mode shapes of the motorizedspindle are studied by modal analysis, the effect of bearing preload on the ordernatural frequency of the motorized spindle is analyzed.(4) Through the harmonic analysis of the motorized spindle, its response to theperiodic force and its variation of the dynamic rigidity are analyzed. The maximumdynamic displacements of the leading-end and middle of the rotor on spindle are studied. Consequently, the theoretic basis for improving and optimizing the motorizedspindle’s dynamic characteristics is provided.