| In high-speed precision machining,the temperature rise of a ball screw will occur due to friction and other factors during operation,and the thermal deformation will greatly affect the accuracy of a ball screw.In order to compensate the thermal deformation of ball screw and improve its accuracy stability,an adaptive method based on carbon fiber composite is proposed to reduce the thermal deformation of ball screw.Firstly,the method of solving the thermal deformation of a ball screw is studied.Based on the theory of heat transfer and finite element method,the thermal-structural coupling analysis model of a ball screw is established,and the thermal deformation is solved.The accuracy of the FE analysis model is verified by experiments.On the basis of that,the FE analysis model of the improved ball screw based on carbon fiber composite is established,and the thermal deformation is determined.Secondly,the Kriging surrogate model of the improved ball screw is established and verified,and the approximate functional relationship between the key design parameters and thermal deformation of the improved ball screw is obtained.Based on Kriging surrogate model,the thermal deformation characteristics of the improved ball screw under single design parameter is studied,and the key design parameters of the improved ball screw are optimized by genetic algorithm and the optimal combination of the key design parameters is obtained.It is shown that the thermal deformation compensate effect of the optimized ball screw is obvious.Thirdly,the dynamic characteristics and compensation effect robustness of the optimized improved ball screw are studied.Modal analysis and harmonic response analysis of the optimized ball screw are conducted.The results show that the dynamic characteristics of the improved ball screw are basically similar to the ordinary ball screw.And the thermal deformation compensation effect of the optimized improved ball screw under different rotational speeds and different overall axial elastic modulus of fiber composites is obtained.The thermal deformation robustness of the optimized improved ball screw is verified.Finally,the actual compensation effect of the optimized improved ball screw is verified by experiments.The design scheme of is improved.According to the experimental results,the thermal deformation of optimized improved ball screw issmaller than the ordinary ball screw.It is important for the practical application of the optimized improved ball screw. |
