The FEM Analysis Of Static And Dynamic Characteristics Of Four-head High Speed Motorized Spindle For Wood-working Machine

As a development trend of modern manufacturing, High speed machining(HSM) can not only significantly improve the processing efficiency of the product, but also improve the surface quality of machined parts, machining accuracy and economy. As a core component of the high speed machine tools, high speed motorized spindle has achieved "zero transmission", with low inertia, high precision, superior dynamic characteristics and a good many of other advantages. Wood processing involves multiple processing including sawing, milling, drilling and other processes. The compact four-head high speed motorized spindle can basically meet the wood-working milling and drilling requirements. To achieve precise and efficient during the processing of wood, it requires that the spindle unit has good dynamic and static performance. So it is important to perform an FEM(finite element method) analysis on its dynamic and static characteristics to improve the performance of the designed spindle.In this paper, the finite element method(FEM) has been used. Based on the finite element analysis software ANSYS Workbench, the four-head high speed motorized spindle for wood-working was simulated and modeled, its static and dynamic characteristics were analyzed and calculated by considering the major factors.This paper includes the following contents:(1) The structure of the four-head high speed motorized spindle for wood-working has been analyzed. Focused on the selection and design of key components of motor configurations, including the way of shaft seal, bearing selection, lubrication and configurations options, motor cooling system design, and balancing design.(2) The dynamic and static stiffness of the angular contact ball bearing has been calculated. Based on Hertz contact theory, the bearing static stiffness has been deduced and bearing dynamic stiffness has been obtained using the finite element method.(3) The static characteristics of the spindle have been analyzed. Based on ANSYS Workbench, through modeling, meshing, and imposing constraints and load processes, static stiffness of the spindle has been derived, and the influence of bearing stiffness and support span on static stiffness of the spindle unit has been analyzed.(4) The modal characteristics of spindle unit have been studied. The natural frequencies and mode shape of the spindle unit has been obtained by the finite element analysis, and its critical speed has also been calculated, and the influence of the stiffness of the bearing on the modal characteristics of the spindle unit has been analyzed.(5) The experimental modal analysis of spindle has been studied. Compared the results of the experimental modal analysis with that of the finite element analysis, the average relative error of them is 2.9%, and the reasonableness of the finite element analysis and the electro-spindle design has been verified.