Research On Reliability Analysis Method Of NC Turntable Based On Vibration Characteristics

As the "blood" of manufacturing industry,CNC machine tools promote the stable development of China's manufacturing industry.In recent years,with the continuous improvement of machining requirements and efficiency,the performance of CNC machine tools has been put forward higher requirements.As the core function component of CNC machine tool,the performance of CNC turntable determines the quality and applicable scope of the machine tools.Compared with the CNC turntable produced by foreign famous manufacturers,the domestic CNC turntable is relatively backward in reliability and efficiency,which has also become the "jam neck" problem in the development of domestic machine tools.Therefore,in order to improve the core competitiveness of domestic machine tools,it is necessary to study the reliability of the core components such as the CNC turntable,in order to improve the performance stability of the CNC turntable.This paper is based on a National Natural Science Foundation project: "Research on the Collaborative Design Technology of Multiple Quality Characteristics Centric on the Meta-motion Reliability of Complex Electromechanical Products".Taking the domestic TK13 series CNC turntable as the research object,the proportional failure rate reliability analysis model,which takes the vibration characteristics of CNC turntable as the covariates,is proposed,which makes up the shortcoming of reliability evaluation method based on fault time,and the effectiveness of the method for the real-time reliability analysis of the CNC turntable is finally verified by experiment.The details of the study are as follows:(1)Firstly,the structure and function of the TK13 series turntable of the research object are introduced,through the collection of CNC turntable failure data,the fault mechanism of the turntable is analyzed.Based on the vibration signal of the CNC turntable,an analytical method for vibration characteristic extraction is proposed through time domain,frequency domain and wavelet analysis.(2)Based on the collected turntable fault data and reliability analysis theory,the reliability modeling and analysis of the collected CNC turntable fault data are carried out by traditional reliability analysis methods.In order to make up for the deficiency of the traditional reliability analysis method,a Weibull scale failure rate model based on the vibration characteristics of the turntable is established for the real-time reliability evaluation of the turntable.The maximum likely estimation method based on genetic algorithm optimization is proposed to obtain the pending parameters of the Weibull scale failure rate model.(3)A CNC turntable operational reliability evaluation test bench was set up,and the covariate of the vibration characteristics obtained by the turntable in different working conditions was added to the Weibull scale failure rate model,the real-time reliability evaluation function of the CNC turntable was obtained,and the effectiveness of the method in the reliability evaluation of the turntable was verified.