Structural Optimization Of Spindle Box For Heavy-load CNC Lathe

This paper focused on structural optimization of spindle box for N-099heavy-load CNC lathe.The purpose of the structural optimization is to reduce the mass of spindle box and seek morereasonable distribution of material. In the mean time, stiffness, strength and low natural frequencies ofthe spindle box remain unchanged. Numerical simulation was performed in HyperWorks system. Themain work is as follows:1. Modal test was conducted on spindle box. The results between experiment and simulationwere compared to verify reliability of finite element model;2. Static and modal analyses were taken to get the displacements and stress of spindle box, aswell as each order modal parameters. The spare of spindle hole’ displacements isn’t very much, butthe stress is low and the first-order natural frequency is much higher than the spindle operatingfrequency. The results showed that strength and dynamic property of spindle box is good;3. Based on the static and modal analyses, mathematical model of topological optimization wasbuilt by constraints of spindle hole’s displacements and four lower-order natural frequencies, and thenapplied minimum volume as objective function. The topological optimization was performed and gota reference model;4. According to the reference model and heat dissipation requirements, a new spindle box modelafter optimization was obtained in SolidWorks. New static and modal analyses were taken. Theresults showed that the mass of spindle box is reduced, as well as the displacements and stress. Andlow-order natural frequencies were increased.