High-speed Electric Spindle Thermal Deformation Of The Finite Element Analysis

Ultra-high speed machining is one of the four advanced manufacturing technologies, the cutting speed of which is 5~10 times higher than traditional cutting speed. High speed machine tool is the precondition for realizing the high speed machining. And the high speed motorized spindle is its heart part. The motorized spindle is equipped with a built-in motor, so that "zero transmission" is realized. Since the parts' stiffness and precision of the spindle units are quit high, and the loads are usually not heavy, so the machining error caused by the cutting force is small. Compared with the conventional spindle, the heat generated due to loss in the built-in motor and friction in the bearings is significant during high speed machining. The built-in spindle's thermal deformation is a main factor on the machine tool's manufacturing accuracy, and the error caused by the machine tool's thermal deformation even reaches 60%~80% of the total manufacturing errors of the part. The thermal analysis of the high speed spindle is quite necessary to in order to reduce temperature-rise and thermal deformation, and that is the main topic of this paper. In this paper, The forces acted on the bearings together with the contact deformation and contact stress are analyzed. That based on the analysis, the motorized spindle is modeled, temperature field, the change of the bearing's stress, and the thermal deformation of the spindle are all done by ANSYS software. At last, a thermal characteristic comparison between the built-in spindle and the built-out spindle is made.