Study on Mechanism of Shaft Fault Suppression Based on Squeeze Film Damper

Considering the action of the squeeze film damper (SFD), the dynamic characteristics of a rotor-rolling bearing system are studied under rub-impact faults. Based on Lagrange equation, the dynamic model of the rotor-rolling bearing system with rub-impact faults and the SFD was established by using the finite element method, and the Newmark method was used to solve equations of the model. The results show characteristics following. Within a certain range of the SFD oil film clearance can effectively inhibit resonance amplitude of the rotor system, and with the decrease clearance of the oil film, the inhibition effect is more obvious. The rotational speed has an important effect on the rotor-rolling bearing system under rub-impact faults. When the rotational speed enters in the vicinity of the major critical speed, the system will occur complex phenomena with the increase of the rotational speed, such as synchronous full annular rub, period-doubling local rub-impact, single period local rub-impact and quasi-period local rub-impact successively. The clearance of the oil film is an important factor affecting the stability of the rotor system, and the appropriate clearance of the oil film has a higher inhibition effect on the rub-impact. In addition, less clearances of the oil film will aggravate the rub-impact, or even nonlinear phenomena.