Nonlinear response of rotor system with bearing dynamic misalignment

AbstractAiming at the nonlinear vibration problem caused by the dynamic misalignment of rolling bearings in the rotating machinery, a rotor dynamic model with bearing dynamic misalignment is established, and the effects of the dynamic misalignment of single and two bearings and the phase relationship of two dynamic misalignment bearings on the rotor vibration characteristics are researched. The effects of bearing clearance, raceway curvature radius, the ball number and radial load on the nonlinear vibration response of the dynamic misalignment bearing-unbalance rotor system are further analyzed. The results show that the dynamic misalignment of the bearing can excite the vibration at twice the rotor frequency, raise the resonance speed and enhance the hardening-type nonlinearity characteristics of the rotor. The influence of dynamic misalignment under two bearings with out-of-phase on rotor resonance is greater than that of the in-phase. The stability of the system can be improved by decreasing the bearing clearance and increasing the curvature radius coefficient. The vibration caused by bearing dynamic misalignment can be reduced by selecting the bearing with more balls and appropriately increasing the bearing load.Keywords: Dynamic misalignmentbearing-rotor systemnonlinear dynamicsbifurcation Disclosure StatementThe authors declared that they have no conflicts of interest.Additional informationFundingThis project was supported by the National Natural Science Foundation [Grant Number 11972112]; the National Key Research and Development Program of China [Grant Number 2020YFB2007802]; the National Science and Technology Major Project [Grant Number J2019-IV-0018-0086]; and the Basic Research Project [Grant Number 20195208003].