The Influence of Misalignment on the Performance of the Herringbone Groove Journal Bearing-Rotor System

Misalignment of the herringbone groove radial bearing can lead to changes in performance and system abnormalities. To investigate the effects of different misalignment modes and magnitudes on the HGJB-rotor system, a coupled dynamic model was established. Based on this model, the influences of parallel misalignment and angular misalignment on bearing performance were analyzed, and the variation law of rotor vibration was revealed. The results indicate that the rotor motion trajectory and bearing dynamic coefficients (including critical journal mass and critical whirl frequency) exhibit time-varying characteristics. Specifically, compared with the aligned condition, a parallel misalignment of δ = 8.0 × 10−6 m reduces the relative film thickness by 17.8% and increases the maximum film pressure by 1.85%. Meanwhile, an angular misalignment of θ0 = 8.0 × 10−4 rad results in a 45.9% reduction in relative film thickness and a 33.1% increase in maximum film pressure. Additionally, the increased misalignment magnitude enhances the rotor vibration amplitude significantly. For instance, the Y-direction displacement amplitude increases by 59.4% under the maximum parallel misalignment. Moreover, the misalignment also alters the axial trajectory of the rotor. Overall, different misalignment modes and magnitudes exert significant effects on the rotor vibration characteristics. The research findings provide theoretical support and technical references for the further development and engineering application of HGJBs.