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Elastic ring squeeze film damper (ERSFD) is widely used for vibration and noise control of industrial rotating machinery. However, the oil film temperature has an impact on the ERSFD rotor system under large unbalanced force and speed, which is not considered in the existing ERSFD rotor system research. In this paper, by coupling energy equation with Reynolds equation and viscosity-temperature equation, an ERSFD model considering oil film temperature is established to investigate the oil film force and temperature distribution. Based on this model, an ERSFD combined support rotor considering oil film temperature is modeled by coupling the dynamic equations of the combined support rotor with the ERSFD reaction force. Then, the influence of oil film temperature on the amplitude frequency response curve and the sudden unbalance response curve of the ERSFD rotor is analyzed. The results reveal that lower temperature decreases the vibration amplitude and shortens the transient process. Finally, the established model and some simulation results are validated by the ERSFD rotor test platform.

Elastic ring squeeze film damper (ERSFD) is widely used for vibration and noise control of industrial rotating machinery. However, the oil film temperature has an impact on the ERSFD rotor system under large unbalanced force and speed, which is not considered in the existing ERSFD rotor system research. In this paper, by coupling energy equation with Reynolds equation and viscosity-temperature equation, an ERSFD model considering oil film temperature is established to investigate the oil film force and temperature distribution. Based on this model, an ERSFD combined support rotor considering oil film temperature is modeled by coupling the dynamic equations of the combined support rotor with the ERSFD reaction force. Then, the influence of oil film temperature on the amplitude frequency response curve and the sudden unbalance response curve of the ERSFD rotor is analyzed. The results reveal that lower temperature decreases the vibration amplitude and shortens the transient process. Finally, the established model and some simulation results are validated by the ERSFD rotor test platform.

In view of the cyclostationary characteristics of vibration signals from aero-engine, the combination of cyclic autocorrelation function and intrinsic timescale decomposition (ITD) has been proposed. According to the proposed method, vibration signals are decomposed by ITD algorithm to obtain the autocorrelation function of proper rotation components (PRC), based on which characteristic extraction and identification of compound faults of rolling bearings is made possible. To validate the effectiveness of method, an analysis has been given to the vibration signals of rolling bearings collected by sensors of different positions in different compound fault modes. As shown by results, the method combining ITD and cyclostationary theory can precisely and effectively extract the characteristic frequency relative to the type of faults and identify the compound faults.