| Abstract:In order to investigate the influence of radial clearance of rolling bearings on the dynamic response of a flexible rotor
system with supporting non-concentricity, a dynamic similar flexible rotor test rig was designed based on the power turbine rotor of a
turboshaft engine. Firstly, the horizontal offset of the front and rear bearing housings was adjusted until an obvious 2X frequency component
can be observed in the response. Then rolling bearings with different radial clearances were sequentially replaced at each support, and the
unbalance response tests were conducted. Finally, a series of experiments were conducted using the control variable method and the flex?
ible rotor test rig, by comparing the variations of amplitudes of 1X and 2X in the responses of different measuring points under different
radial clearances, the influence and mechanism of rolling bearings radial clearance on rotor vibration responses at different supports were
analyzed. The results show that the phenomenon of "frequency locked-up" and the resulting resonance can be observed during the experi?
ments; Appropriate combinations of rolling bearings radial clearances can significantly reduce the vibration of the rotor system, with a
maximum reduction of vibration amplitude over 85%; the vibration reduction mechanism is that the radial clearance could compensate for
additional unbalance forces and moments caused by supporting non-concentricity, however, the compensation effects of the bearings at dif?
ferent axial positions varies, resulting in different vibration reduction effects. The findings of the research are of significant engineering
value for the vibration control of the aeroengine. |
