Reliability Assessment Of Reducer In Small Sample Based On Bayes Method

The gear transmission as one of the most commonly used mechanical transmission form and the realization of this transmission form usually relies on a kind of mechanical device which we called reducer is widely used in machinery, electronics, aviation, aerospace and other fields. And the performance of reducer directly affects the accuracy, stability and reliability of the system accuracy, so the reliability of multi-stage gear reducer research and evaluation has an important significance for the engineering practice and the reliability design of the multi-stage reducer has high practical value.This paper chooses the tertiary spur gear transmission system of the turret slewing mechanism of a certain warship as the research object and we obtained the priori information of the transmission system based on modal characteristics and gear contact dynamics analysis that we get by using finite element technology, and then combining with test data of the reducer by a small sample test, we get the posteriori information of the transmission system by using the Bayes theory to complete the fusion calculation of the two part data, and we can make the reliability evaluation of the reducer based on the experience information. In this paper, the main research work is as follows:(1)First of all, we convert the prior information obtained by virtual simulation experiment to a certain type that we can need. In this paper, the prior information is stress distribution information acquired through virtual simulation experiment. Before we carry out the Bayes fusion calculation of small sample lifetime data and the prior information, we must convert the stress distribution to the lifetime distribution, which is the preparatory work of subsequent reliability evaluation of the system Based on the Bayes method.(2)Then, we obtain the priori reliability by use of the stress strength interference model. When we carry out the Bayes reliability assessment using reliability as the prior information, we need to solve the priori reliability. However, we get the stress distribution information by simulation experiment, so we need to expand the calculation of the intensity distribution of the structural units, and then we can solve the priori reliability by using of the stress strength interference model.(3)At last, we make a fusion calculation of the prior information and the small sample test data based on the Bayes method. Due to the experimental condition limitation, we don’t make a small sample test truly. In this case, we make respectively estimate and assumption for the possible data of changes in the scope of the small sample test data,and we finally complete reliability assessment of the system by combining the estimate and assumption data of the small sample test data with simulation data.