Design And Simulation Of Machine Tool Spindle Structure Based On Stiffness Optimization

It is a hardware compensation method to improve machining precision in the structure design phases, which is the foundation of the effective implementation of other software compensation methods. How to distribute the stiffness of the spindle effectively is the crux to improve machining precision in the design phases. The article targets the spindle of a vertical machining center, through the method of deducing the expression of constraint conditions in the mathematical model which represent spindle structure design process, based on the equal strength results, to optimize the stiffness of the spindle with actual conditions. Through the finite element modeling and simulation to verify the design results. The detailed contents are as follows.(1) Established the preliminary mathematics model of spindle structure design, calculate the constraint expression of strength condition and stiffness condition.(2) Calculate the minimum size distribution results which satisfied the strength condition, and discuss the features of the size distribution which satisfied the stiffness condition, they are not only.one of the size distributions is worthly to get because it conform to principle which the meterial distribution reasonable.(3) The proportion of the minimum size distribution which satisfied the strength condition approximately conform to the principle of stiffness distribution reasonable, so it can be treat as a base in the structure optimization design when hop to increase the stiffness. On the basis of this madification, we can get a approximate stepped shaft model, and simulate it in the FEA software.(4) Find ways to improve performance of spindle through the expression of the constraint inequalities, and optimize the support span and inertia of the stepped shaft model as multi-target optimization problem.(5) Simulate the optimized stepped shaft model in the temperature field, make a comparison with the spindle which is designed by traditional experience mthod.The simulation results show that taking the limit size distribution under the condition of the strength constraints as the designing basis of stiffness optimization, can achieve the goal of improving the spindle machining accuracy.