No-trial-weight Identification And Accurate Description Of The Unbalance Vector For Rotor Bearing System

The unbalanced fault is the main cause of the vibration of the rotor bearing system,and it is also a common phenomenon in the rotor bearing system.When running at high speed,even a small imbalance will cause violent vibration,which will have a great impact on the running state of the rotating machinery.Therefore,how to suppress the unbalance vibration becomes a key problem of rotor system.In this paper,the dynamics model of the rotor bearing system is built,and on this basis,no-trial-weight identification of rotor unbalance based on modal equivalence and accurate description of the anisotropic rotor unbalance vector are studied.The main research contents are as follows:Firstly,the five degree of freedom dynamic models of rotor and counterweight disc are established by finite element method respectively.The stiffness matrix and damping matrix of sliding bearing can be calculated by analyzing the structure and force.The finite element model of high-speed rotor bearing system can be obtained by integrating each element matrix.Through the MATLAB simulation analysis of this model,the frequency response curve is obtained,and compared with the results of the modal experiment.The results of the two have a high matching degree,which indicates that the model is accurate and reliable.Secondly,no-trial-weight identification method of rotor unbalance based on modal equivalence is studied.The mechanical behavior of the unbalanced rotor is analyzed by the dynamic model,the principle of unbalanced force equivalence is studied,the correlation between unbalanced response and unbalance is established on the main coordinate,and then a method of unbalanced suppression based on modal equivalence is proposed to solve the amplitude and phase of unbalance.The effectiveness of the method is verified by MATLAB simulation analysis,and the experiment is carried out on the multi-functional rotor test bench.The experimental results showed that the dynamic balance recognition method without trial weight can accurately and quickly identify the system unbalance,and the unbalanced vibration of the system is effectively controlled after adding the counterweight.Finally,the unbalanced response of the anisotropic rotor bearing system is analyzed,theinfluence law between the unbalanced state and the unbalanced vibration energy is analyzed,and the vibration energy is proposed to accurately characterize the unbalanced state of the rotor.Based on the dynamic model of rotor bearing system,the feasibility of the balance description technique is verified by MATLAB simulation.Then the functional experiment is carried out on the multi-functional rotor bench to verify the higher accuracy of the vibration energy to represent the unbalance.And the effectiveness of the vibration energy to characterize the unbalanced state is verified by experiments.In general,no-trial-weight identification and accurate description of the rotor unbalance vector are studied in this paper,and the corresponding recognition and description methods are given,which lay the technical foundation for the efficient and accurate dynamic balance implementation of the rotating machinery system and guarantee the safe and stable work of the rotating machinery system.