Research On Frequency Reliability Of Power Servo Turret System

At present,CNC machine tools are widely used in the design and processing of automobiles,ships,bridges,aerospace,communications equipment,medical equipment and other manufacturing industries.Due to the significant improvement in performance requirements of modern mechanical equipment products,the requirements for high efficiency and high reliability of CNC machine tools are receiving more and more attention.As an important functional component of modern CNC machine tools,the power servo tool holder transmits the motor torque to the load end of the power tool through high-speed operation during the working process,so as to cut the workpiece and cut the tool in the working process.The tooth surface stress received and the exciting force of the tool holder are constantly changing.Under the joint action,the tool holder system resonance problem may occur,which has an impact on personal safety and engineering efficiency.In this paper,the dynamic analysis and reliability evaluation of a typical gear drive system with dual servo power tool holders are carried out,and the frequency reliability and sensitivity of the tool holder are studied.The main research work is as follows:(1)This thesis firstly introduces the background and significance of reliability and sensitivity analysis of power servo tool holders,and summarizes the development and research status of CNC machine tools,power servo tool holders,artificial neural networks and reliability theory.(2)Secondly,the whole machine model of the dual servo power tool turret analyzed in this paper is introduced,and the solid modeling and assembly of the gear transmission system are carried out with solidworks.A detailed mathematical description of the excitation of the gear transmission system and a preliminary theoretical introduction to the vibration mode theory are given.(3)Based on Newton's second law,the dynamic equation of the tool post gear transmission system is established by the lumped mass method.According to the nonlinear coupling vibration characteristics of the multi-stage gear transmission system,the vibration characteristics of the tool post drive system under the internal and external excitation coupling are studied,and the vibration displacement and vibration speed of the influence parameters such as the excitation frequency on the gear system are analyzed.Impact.The theoretical first-order natural frequency is calculated by the differential equation of motion and compared with the results of vibration modal analysis to verify the stability of the transmission system in the model.(4)Furthermore,the failure mode and impact analysis method are used to analyze the failure form basis of various components of the dual servo power tool block gear transmission system,and the degree of influence on the system reliability is sorted,and the components with greater influence degree are calculated for reliability.Based on the theory of gear fatigue contact strength and gear bending fatigue strength,the reliability of the gear in the model is calculated.Based on the bearing contact fatigue theory,the reliability of the rolling bearing is calculated.The reliability model of the gear-bearing system under the capacity-related conditions is calculated.Reliability of the power servo tool holder gear transmission system.(5)Finally,the parameterized modeling of the tool holder is carried out.The size parameters and material parameters are used as random variables.1000 sets of data about random variables are generated in the Isight test design,and combined with BP neural network theory to obtain the natural frequency of the whole machine.The functional relationship between size parameters and material parameters is based on the frequency reliability theory to analyze the frequency reliability and sensitivity of the whole machine,sort the sensitivity values,analyze the influence of random parameters on the frequency reliability of the whole machine,and guide the subsequent reliability design optimization,the study.