Research On Life Prediction For RV Reducer Based On Accelerated Degradation Testing

This subject comes from the National Natural Science Foundation of China "The recession prediction of rotating mechanical properties based on the method of functional approximation".With the continuous development of space science and technology in China,various types of spatial mechanisms are from "a single short time use" to become "a long time uninterrupted use".Such changes have put forward higher requirements for the reliability and durability of the spatial mechanism.As a new type of high torque transmission mechanism,RV reducer is widely used in various kinds of spatial mechanisms and industrial robots.But at the present stage,the RV reducer is the key part of the rotating mechanism,and there is no method and system to predict the reliability life prediction.It will bring a great impact on the maintenance and repair of the RV reducer,and even cause immeasurable damage to the overall mechanism.In view of the above problems,this paper analyzes the life prediction of RV reducer based on accelerated degradation testing.The reliability life model of RV reducer is established by processing the data of the product performance degradation.Therefore,it is possible to predict the reliability life of the RV reducer under normal operating conditions.The specific research contents of this paper are as follows:1.The failure mechanism of the RV reducer is defined.First of all,this paper analyzes the common failure modes and causes of all kinds of reducers,and compares with the RV reducer itself.Secondly,it refers to the actual use environment of RV reducer,and focuses on the wear and consumption of the key parts of the system.Finally,the failure mechanism of RV reducer is clearly analyzed.2.The accelerated degradation testing of the RV reducer is based on the pseudo failure life.Firstly,this paper determines the accelerated testing plan,including the reasonable accelerated stress and the number of samples,etc.,and then sets up the testing platform of the accelerated testing system,and the performance degradation data of samples are collected under different conditions.3.Some reliability data of product life are obtained by processing the degradation data.Firstly,the performance degradation model of RV reducer is determined based on the traditional degradation model and performance degradation data,and the pseudo failure life of the product is obtained by referring to the failure threshold value.Secondly,distribution function of the reliability life of the RV reducer based on Weibull distribution is fitted by chart estimation method and MATLAB.The hypothesis testing based on Minitab verifies the rationality of product life model.Finally,this paper estimates the parameters of Weibull distribution based on the extreme value distribution and the Gauss-Markovian theorem,and obtains the reliability life data of the RV reducer under normal working conditions.4.Analysis and verification of the key link of accelerated degradation testing.Firstly,this paper establishes the performance degradation model based on the theory of Brown motion,and analyzes the life function of the RV reducer,so as to verify the rationality of the product life model.Secondly,the actual torsional stiffness is obtained by finite element simulation analysis of the RV reducer based on the torsional stiffness conditions,and compared with the index of product design,so as to verify the rationality of the accelerated stress selection in accelerated degradation testing.