Dynamic Research And Fault Simulation On Cylindrical Roller Bearing Based On Explicit Dynamic

As one of the most widely used mechanical parts, rolling bearing is one of the most easily damaged parts. The fault of rolling bearing can lead to the failure of the whole machine, and cause serious economic losses and casualties. So the research on the dynamic characteristics of rolling bearing and the analysis of differences in the dynamic characteristics of the normal operation and fault situation as well as providing theoretical basis for the fault diagnosis of rolling bearing have very important practical significance.First, this paper introduces some of the common fault forms of rolling bearing and their diagnostic methods, describes the basic mechanics theory of the rolling bearing, and establishes the dynamic theory model of rolling bearing. On the base of the above model, the relative motion relations between the various parts of the rolling bearing and the force on roller, cage, inner ring and outer ring were analyzed. The paper also introduces the basic thought of finite element method to solve problem briefly, the functions and their features, application range, unit type and contact model of ANSYS/LS-DYNA, which provides the theoretical basis for the explicit dynamic analysis of rolling bearing. This paper takes the GB2612cylindrical roller bearing, which was used in gear box, as an example, completing the explicit dynamic simulations under the condition of normal operation and fault operation with spalling on outer raceway. The finite element model of cylindrical roller bearing was established by using of APDL and by establishing material constant, contact model, boundary conditions and load suitable for the condition of normal operation and fault operation with spalling on outer raceway. Compares the equivalent stress nephogram and section stress nephogram in the condition of normal operation and fault operation with spalling on outer raceway, as well as displacement, velocity and acceleration that varied with time. By using both FFT and Cycle Autocorrelation Function methods, we analyzed Y direction acceleration signal obtained by simulating the condition of normal operation and fault operation with spalling on outer raceway. Then by using Cycle Autocorrelation Function, analyses Y direction acceleration signal measured in testing tag under the condition of normal operation and fault operation with spalling on outer raceway. At last, we contrast simulating result with testing result by Cycle Autocorrelation Function analysis.Through the analysis and comparison of simulation and experiment results, we can discover when spalling occurs on outer raceway, contact stress increases obviously in the fault area. The displacement, velocity and acceleration of the node is periodic changing signal caused by rolling elements periodically going through the outer ring. We can find the significant failure frequency by contrasting the results which by using Cycle Autocorrelation Function analyses Y direction acceleration signal that belong to simulation and experimente.Those results proved that the simulation method is feasible. And this method provides the guidance for bearing fault diagnosis.