Dynamics Study of Multi-Supports Rotor Systems with Bearing Clearance Considering Angular Deflections

Bearing clearance, prevalent in multi-supports rotor systems of aero engines, exerts a significant influence on the dynamics of rotor systems, actuators, and aero engines. The essence of it lies in the complex mechanical effects between the bearing and support. These effects become more complicated when significant relative angular deflections between the bearing and support exist, which is rarely considered in previous studies. In this paper, a model of support structure with bearing clearance considering angular deflections is proposed, and a mechanical model of the multi-supports rotor system with bearing clearance is developed. The dynamic response of the multi-supports rotor system with bearing clearance is investigated by numerical calculation and experimental verification. The results indicate that, in addition to the rotational frequency, remarkable harmonic frequency components occur in the response, which are generated by the relative movement and periodical collision between the bearing and support, and the relative angular deflections between the bearing and support have a significant impact on the amplitude of them; reducing the bearing clearance or increasing the misalignment both leads to a notable increase in the amplitudes of the harmonic frequency components.