Tribo-dynamic modelling and analysis of gear-rotor system: Effects of stationary and nonstationary conditions

Abstract

As crucial indicators of stability and service reliability, dynamic and tribological behaviors of gear-rotor system are investigated under both stationary and nonstationary conditions based on a new tribo-dynamic modelling approach. In the global dynamic model, the shaft compliance is considered with the gyroscopic effect, and the dynamic meshing force formulations under elastohydrodynamic and hydrodynamic lubrication states are integrated. The stepwise coupling strategy is developed to describe the two-way interaction between vibration and lubrication parameters in each time step. The methodology is validated numerically and experimentally. The investigation shows that high-speed and light-load conditions result in chaos, accompanied by extremely high subsurface stress. Higher additional torque during the acceleration and deceleration brings about rotating speed oscillation and more complex frequency components. Faster torque fluctuation contributes to multi-periodic and chaotic motions. The non-monotonic relationship with maximum pressure and minimum film thickness is also observed. Disturbing loads in the forms of sudden load variation and random load disturbance have limited impacts on system tribo-dynamic performance generally. The methodology and results provide useful guidelines for the tribo-dynamic design of gear-rotor system.