The Finite Element Analysis And Optimization Design Of NC Machine Electric Spindle

High speed machining technology in mechanical manufacturing industry is abreakthrough technology revolution. Electric spindle technology plays an important rolein the field of efficient processing technology, influencing the machining accuracy of ncmachine tools, surface quality and machining efficiency. So making static, dynamiccharacteristics and the thermal modal analysis and finite element analysis in motorizedspindle and making optimization design on its structure to improve the level of machinetool design and production efficiency has important significance.This topic main research content is as follows:(1) Determining the structure of electric spindle, spindle motor, bearing, bearinglubrication system and spindle cooling system type, completing the main structure ofmotorized spindle unit parameter design, finally finishing shaft through mechanicaldesign manual design, calculate the first order critical speed of shaft.(2) static characteristic analysis of the electric spindleAngle contact ball bearing structure modeling and mechanical properties analysis,according to the calculation results to obtain the axial pre-tightening force influence onthe radial stiffness of bearing.Using Pro/E modeling software to establish three-dimensional model of motorizedspindle, the model was directly imported into ANSYS finite element analysis software,through static deformation deprogram of motorized spindle, validating the motorizedspindle static stiffness can meet the design requirements.(3) dynamic characteristic analysis of the electric spindleCompleting the modal analysis and harmonic response analysis of motorizedspindle according to ANSYS dynamic analysis module, for getting modal andharmonic response analysis feature, validating the motorized spindle structure designcan effectively avoid the resonance region.(4) the electric spindle structure optimization designFirst introduced optimization design concept, the rule of optimization, optimizationmethods, on this basis, to establish the parameterized finite element model anddetermine the design variable, objective variable and state variable. By optimizing thespindle of the static and dynamic characteristics before and after contrast, validating motorized spindle structure parameters is more reasonable after optimization.(5) analysis of hot state characteristics of motorized spindleCompleting heating of the motorized spindle motor and the bearing friction heatloss calculation, on the basis，the motorized spindle thermal analysis model wasestablished, using the finite element analysis software to analyze and solute. Carryingthe finite element thermal analysis on the improved motorized spindle model again,analysis results show that the bearing outer ring for water cooling the measures toimprove the bearing’s temperature field distribution has obvious effect.