Simulation Of Typical Coupling Fault Of Engine Rotor-Bearing-Support System And Research On Transfer Characteristics

Due to the complex structure of the aero-engine,numerous parts,high operating speed and other factors,engine vibration failures occur frequently and the failure mechanism is relatively complicated.In particular,the rotor-bearing-support system is a key structural system of an aero-engine.Once a failure occurs,the vibration will exceed the standard,and even serious accidents will occur.Therefore,carry out the simulation of the coupling vibration fault of the rotor-bearing-casing support system,research the characteristics of the bearing fault and the coupling fault with unbalance and different heart,and explore the mechanism of the fault feature and its transfer rule on the casing.For the engine,It is of great significance to trace the source of vibration fault diagnosis and troubleshoot the coupled vibration of the complete machine.Based on the multi-body transient dynamics and finite element co-simulation,the main bearing fault simulation of the engine is completed.After simulating the nonlinear contact force of each part of the main bearing and the flexible treatment of the thin-walled support,a dynamic model of the bearing-thin-walled support system is constructed.Realized the simulation of bearing outer ring,inner ring,cage and rolling element faults.For outer ring faults,the impact of the peeling width and number of outer ring defects on bearing vibration was analyzed,and the impact of the change of the two defect angles of the outer ring on bearing vibration was analyzed.Impact.The transient contact force of the outer ring on a single rolling element,all rolling elements,and thin-walled support is studied,and the velocity and acceleration responses of the thin-walled support structure are analyzed,and the mechanism and response characteristics of bearing fault characteristics are obtained.Based on the joint simulation of multi-body transient dynamics and finite element method,a simulation method for coupling faults of bearing faults,unbalanced high-pressure rotor and different heart is proposed.After simulating the nonlinear contact force of each part of the main bearing and the thin-walled support flexible treatment,a dynamic model of the high-voltage rotor-rolling bearing-local thin-walled support system is constructed.By studying the transient contact force of the outer ring on all rolling elements and thin-walled supports,and the response of velocity and acceleration of the thin-walled support structure,the fault characteristics in the coupling state are obtained.Two typical coupling faults,namely outer ring fault and high-voltage rotor unbalanced coupling fault,outer ring fault and high-voltage rotor support non-concentric coupling fault,are identified through different fault characteristic frequencies,which can provide support for the identification of these two coupling faults.Taking the thin-walled casing as research object,based on the inherent properties of the casing and the transfer function of different nodes of the casing,fault characteristics of the typical outer ring,the coupling fault characteristics of the outer ring fault and the unbalanced high-pressure rotor,and the outer ring fault characteristics are further studied.Transfer rule of ring fault and rotor differential center coupling fault characteristics on thin-walled casing.By analyzing the characteristic frequency of the outer ring fault and its harmonic frequency in the acceleration of different measuring points of the casing,it can provide a reference for the type of bearing fault.Diagnosis of non-concentric coupling faults,outer ring faults and high-voltage rotor unbalanced coupling faults provides references.