Research on Dynamic Modeling and Decoupling Methods of Planetary Gear Trains in Wind Turbine Gearboxes with Journal Bearings
In the dynamic modeling of planetary gear trains,the influences of nonlinear oil film forces or linear stiffness damping forms on system dynamics characteristics were often considered.The former had high simulation accuracy but high computational costs,and the latter had high computa-tional efficiency but ignores the time-varying effects of oil film forces and journal sleeve eccentricity,resulting in limited simulation accuracy.Therefore,a 2MW wind turbine gearbox was taken as the re-search object herein.A time-varying linear stiffness damping model of the journal bearing was estab-lished,and a calculation method for the additional eccentricity correction force of the journal bearing considering the time-varying eccentricity of the journal sleeve was proposed.Then,the time-varying linear stiffness damping model was coupled with the additional eccentricity correction force by using the coordination relationship between the carrier-pin and planet.Finally,a dynamic model of the plan-etary gear trains in wind turbine gearboxes using journal bearings was established,and the effects of operating conditions and bearing parameters on the calculation accuracy and dynamic system responses were compared and verified through experiments.The results indicate that the fluctuation of dynamic meshing force in gear pairs may cause periodic changes in the stiffness damping coefficient and addi-tional eccentricity correction force of journal bearings.The proposed model may effectively predict system responses,especially planetary gear vibration responses,under stable and transient operating conditions.Reducing the width-diameter ratio and gap,increasing input torque may improve the sys-tem's load sharing performance.