The Structure Design And Performance Analysis Of Motorized Spindle Used In Machining Center

High-speed machining processing as an advanced manufacturing technologyof collectinghighly effective, high quality, low consumption in one, has a strong vitality and a broadapplication prospect. To apply and develop high-speed processing technology, must first havethe well performance CNC machine tools, while the high-speed motorized spindle is the core,and the performance of it will directly determine the performance of high-speed CNC machinetools. According to the actual demand, this paper took the structure design and performanceanalysis of the electric spindle as the key point, first studied the key technology of spindle andcarried out a preliminary design of the key parts, then gave a detailed design of the structure,last carried out a static and dynamic analysis by the finite element analysis technology, and allof these had a great significance to improve the performance of electric spindle. The study wasopened in the following areas:1. Combining with the problems ofthe CNC machine tools’ motorized spindle, carried onan analysis of the key technology, made a detailed research of the bearings and its lubricationtechnology, the spindle’s heat output and cooling technology, tool clamping system anddynamic equilibrium technology, then according to the research goals, gave a preliminarydesign of these key parts.2. Carried on an overall design ofthe spindle, including the bearing selection and stiffnesscalculation, motor selection, a calculation of the inner and outer diameter, span, overhang andso on critical dimension parameters. On this basis, carried on the theoretical calculations of theshaft, such as overall stiffness, rotation accuracy, critical speed and cutting force in the typicalprocess conditions.3. Established the finite element model of the spindle system—bearings-rotor-shaft-theinterference connection parts, and carried on the static characteristics analysis of the spindleby the ANSYS software, to get the static stiffness; then, made the modal analysis, extractingthe first six order vibration mode and natural frequency, and through the calculation, obtainedthat the critical speed of the spindle is much higher than its highest speed, so would not occurresonance; last, carried out the harmonic response analysis of the front-end and the keyposition of the spindle, got the frequency-displacement response relationship of the key pointsand the dynamic stiffness of the spindle, then obtained the weak link and the dynamiccharacteristic within the scope of the maximum speed. By these analyses, had confirmed thatthe structure is rational, and the spindle has a good dynamic and static characteristic.