Abstract:

For the diagnosis of misalignment-rubbing coupling fault of rotor-sliding bearing system caused by misalignment fault, based on nonlinear finite element method, the mechanical model and finite element model of dual-disc rotor system with misalignment-rubbing coupling fault are established by short bearing oil film force, equivalent misalignment torque and Hertz contact theory. And with the augmented Lagrange method contact constraint conditions is dealt to ensure that the rotary table and casing contact each other meet boundary penetrating depth within the prescribed tolerance range. Combined with experimental study and simulation analysis, relevant dynamic characteristic of misalignment-rubbing coupling fault rotor-sliding bearing system is studied , with the different speed conditions. It is shown that rubbing fault is the leading role in the coupling fault, misalignment fault will inspire high power spectrum in a subordinate position. With the increasing of rotational speed, the main composition of the system frequency is the high power frequency. And it is gradually from the quasi periodic motion to chaos motion state. As the result of misalignment moment and rubbing force, the phenomenon of oil film instability is partial inhibition. The first and the second order of oil film oscillation phenomena are lagging behind. The results of the study provided the basis for the diagnosis of misalignment-rubbing coupling fault of rotor-sliding bearing.

Key words: coupling fault, dual-disk rotor, oil film force, rubbing, sliding bearing, misaligned bearing