Thermal Analysis On TH5650 Vertical Machining Center's Motorized Spindle

In the late decades, with the development of science and technology, machine tool products and equipments also develop to high-speed, efficient, precise, multi-function and automation. The new spindle system, which is named motorized spindle, unites high frequency alternating-current machine to spindle, is widely applied to high-speed machine tool products. As a result of motor united to spindle and running at high revolution, the whole system especially spindle's temperature ascending and temperature distribution determines the machine's processing quality. The dissertation is about the research of TH5650 vertical machining center manufactured by the Limited Corporation of Xi'an Transportation University & Kunming Machining Tool. The aim of the thesis and study is to enhance the thermal performance of the machining center.In order to analyze the thermal characteristic, the Finite Element Method(FEM)is used to build the thermal-model of the motorized spindle. Then, the temperature fields and the thermal-stress fields of structure are analyzed. In conclusion, factors which influence the thermal characteristic of motorized spindle most were found and analyzed before the improved measures are brought forward.In this paper, it is mainly focus on aspects such as the principle of bearing's heat generation and calculation, heat transfer boundary conditions'analysis and calculation, the analysis of motorized spindle's temperature fields and thermal-stress fields, measures to improve the motorized spindle's thermal characteristic. On the running condition of its designed max revolution at 8,000r/min, main researches which have achieved are listed as below:(1) The bearings'movement and mechanical circumstances is analyzed on the condition of enduring preload. The causes of bearing's heat generation are revealed, and calculate the heat generation amount of every bearing, analyze the main factors which have an effect upon bearing's heat generating.(2) By using the heat transfer fundamental and related expressions, the motorized spindle's convection heat transfer coefficients(the thermal boundary conditions of FEM)are calculated.(3) Choosing ANSYS 9.0 edition software as analyzing tool, the motorized spindle's finite element geometrical axis-symmetric 2D plane model is built up. Then,after the model was meshed and refined, the FEM is built up.(4) Using the results from(1),(2)steps, the FEM's loadings and thermal boundary conditions are defined and loaded on; ANSYS software calculates nodes'steady state temperatures automatically.(5) The temperature field and temperatures ascending of critical components are analyzed,and measures how to improve the thermal characteristic of the motorized spindle are discussed and brought forward on the model.(6) The motorized spindle FEM's stress field is calculated and formed in ANSYS software after transformed calculated temperature as a loading on nodes; then, the thermal stress of critical components are analyzed and discussed.After the thermal and thermal-stress analysis of the motorized spindle is finished, here comes to conclusions as below:(1) The thermal steady state analysis of motorized spindle shows that the average...