Dynamical Models Analysis Of Aircraft Engine Rolling Bearing

In order to realize the significance of guiding the actual project, this paper analyzes dynamic characteristics of the rolling bearing in a system of aero-engine rotor Based on the previous research results and Hertz contact theory, we analyze the dynamic characteristics of the rolling bearing by MATLAB and ANSYS. First, we introduce the establishment of rolling bearing dynamics models of different DOF in detail, which respectively are 2DOF,3DOF and 5DOF theoretical dynamic models, and focus on the research on 2DOF and 3DOF theoretical dynamic models by MATLAB to get numerical solutions, then analyze the influence of various geometric and physical parameters on dynamic characteristics of the rolling bearing; As to the 2DOF model, we analyze phase plane and amplitude-frequency response, and the results indicate that the characteristics of phase plane and amplitude-frequency response changes with the variation of rotation speed, clearance and damping parameter, particularly the clearance is a more significant influence factor relative to the damping parameter; As to the 3DOF model, we mainly analyze and sum up the characteristics of phase plane with the variation of axial force. By the research we find that the results of 3DOF model is more complex than that of 2DOF model, and 3DOF model has more reference value when the actual project needs to consider the effect of the axial force on the rolling bearing. Second, we analyze dynamic characteristics of the rolling bearings by ANSYS and find that the rolling bearing exhibits nonlinear stiffness at different angular positions and the nonlinearity reduces with the increase of loads, which provide the basis to select right magnitude of the force as the data points that are necessary to fit a variable stiffness curve. Finally, we can see that the result of ANSYS simulation shows a periodical variation of stiffness and the case is consistent with the theoretical calculation results by MATLAB, furthermore, the ANSYS simulation result is proved to be effective and rational to revise variable stiffness parameters of the different DOF models which promoting the theoretical analysis is more close to the case of accrual project.