Research And Design Of New Shaft Core Of Electric Spindle Based On Structural Bionics

High-speed machining has good application prospects due to its advantages of high productivity and high precision.As a key component of high-speed machining equipment,the dynamic performance of the electro-spindle directly determines the machining quality.There is a gap between the high-speed dynamic performance of the domestic motorized spindle and the international advanced level.Starting from changing the structure of the motorized spindle shaft core,this paper develops a new type of high specific stiffness shaft based on the theory of structural bionics.On the premise of ensuring that the stiffness and strength meet the requirements,the dynamic performance of the bionic shaft core and its own heat dissipation performance of the shaft core are analyzed,and the bionic structure is improved according to the analysis results.The specific research contents are as follows:(1)Based on the structural bionic idea,select high specific stiffness bionic prototype.According to the fuzzy similarity theory,the relationship between the mechanical properties of wheat stalk and its microstructure was analyzed,and the biomimetic design criteria were extracted to obtain the biomimetic configuration.The finite element stiffness analysis of the bionic motorized spindle was carried out,and the bionic shaft core was generated by 3D printing and strength experiments were carried out to determine the structure of the bionic shaft core.(2)To analyze the dynamic characteristics of the bionic shaft core,the transfer matrix method and the finite element method are used to conduct modal analysis on the bionic shaft core-rotor-bearing system based on MATLAB and ANSYS Workbench software,respectively,to obtain its natural frequency and mode shape,The critical speed is calculated based on this;the results obtained by the two methods are compared,and the harmonic response analysis is completed by means of finite element software on the basis of modal analysis.The thermal-structural coupling analysis is carried out on the bionic shaft core,and the temperature rise and thermal displacement of the shaft core are solved.The above analysis results are compared with the prototype to verify the many advantages of the bionic shaft.(3)For the bionic configuration,the response surface optimization is carried out with the static maximum deformation as the state variable and the natural frequency as the objective function,and the bionic structure is further optimized to obtain the optimal parameters of the bionic structure.