Dynamic And Thermal Characteristics Analysis And Experiment Research Of High Speed Milling Motorized Spindles

High-speed machining technology has become the mainstream of modernmanufacturing, a variety of CNC machine tools with high-precision, high-efficiency,low-energy consumption have been widely used. Spindle is the core feature ofhigh-speed machining CNC machine tools, whose performance directly affects theprocessing precision and cutting quality of the entire machining system, the analysis ofdynamic performance and thermal properties of the spindle is significant for its structuredesign optimization and performance improvement.In this paper, the high-speed milling spindle DGZX-1425is used as the researchobject, and its structural design is verified, the theoretical simulation and experimentalstudies are combined to create a reliable finite element simulation model of the spindle,the specific works are carried out as follows:First, the dynamic analysis of angular contact ball bearings will be made, thedynamic equilibrium characteristic equations are solved to analyze the implications ofspindle speed and preload on the bearing contact angle for radial stiffness, laysfoundation for the dynamic analysis of spindle theoretically.Second, analyze two groups of bearing radial stiffness. They are loaded in frontand backend of DGZX-1425, finite element simulation analysis of the simplified modelis solved in the ANSYS Workbench, which analyzes vibration mode shapes, naturalfrequencies and the critical spindle speed at free state;cutting force is calculated byempirical formulas. It is applied to the front face of the spindle to obtain its dynamicresponse shift under working frequency. The spindle front face and end face, the rotorfront face is selected as test point to calculate spindle dynamic stiffness. Analyze theaffecting factors of the dynamic characteristics and propose improvement measures.Third, based on engineering thermodynamics and heat transfer theory, analyze themain heat source and the heat transfer and cooling system of the spindle, and obtainthermal boundary conditions of the spindle. Investigate the impact principles of spindlespeed, cooling water flow, bearing preload and other parameters. The finite elementsimulation model for thermal analysis is established to obtain the distribution charts oftemperature, heat flow and thermal strain under thermal equilibrium conditions, and analyze the main influence factors on spindle thermal characteristics.Fourth, in order to verify the accuracy of the simulation analysis method, modaltesting, vibration testing and temperature testing experiments of the spindle are carried.The reliable experimental test equipments and test methods are selected, by changingthe main related parameters such as spindle speed, bearing preload, etc. to research onthe factors of the spindle dynamics and temperature characteristic. The causes of errorsare analyzed by comparing the results of simulation analysis with experimental results.