The Dynamic Friction Moment Gathering System Applied To Failure Diagnosis Of Sensitive Bearings

Sensitive bearings are mainly used in the domain of high accuracy navigation such as aerospace, aviation, ships and precision guided munitions as well. The values and volatility of friction moment related to sensitive bearings directly affect the orientation and precision of the navigation saystem as well as longevity of the bearings, even threatening main engine's security. There are multi-factors affecting friction moment and volatility such as the bearing structure parameter, the material performance, the operating condition, and lubricant, etc, which is a complex problem. The less the friction and volatility is, the higher the stability and precision will be.This dissertation starts from the introduction to the background and the goal of the research. Based on the working principles of the bearing dynamic friction moment measuring instruments, systematic design thought is specifically formulated. To enhance the precision of system gathering, the improvement program related to hardware is worked out: the hardware which the system needed is equipped, the related anti-electromagnetic interference measure has also been taken. Then the detailed software realization of friction moment gathering system is put forward. Finally, statistical analysis of the breakdown factors, of which the data are obtained from test, is carried out. And the failure diagnosis model is established.The bearing dynamic friction moment gathering analysis system based on the virtual instrument technology has realized data acquisition of bearing friction moment signals with high speed and large capacity, guaranteing the precision of data analysis, realizing real-time memory and demonstration of the sampled data, carrying on time domain analysis and frequency range analysis. Much work had been done to make up the bearing diagnose system based on the friction moment.In theory, through application of statistics to the failure diagnosis, the establishment dynamic friction moment diagnostic model has achieved diagnosis accuracy rate of 70%, then proposing one kind of theoretical research direction for the sensitive bearing's dynamic friction moment diagnosis. In application, the improved sensitive bearing dynamic friction moment measurement system increases its precision by approximately 1.4%, more accurately reflecting actual profile of moment. Therefore, this research facilitates the manufacturers and the users of sensitive bearing in the examination and the analysis of the product-related dynamic friction moment, and also provides theoretical support for and the improvement way of producing and employing precision bearings with higher reliability.