Dynamic flexible-tribo coupling modeling and analysis of closed differential herringbone gear systems considering thermal-elastohydrodynamic effects

This article investigates the multiphysics coupling mechanism among Dynamic Thermal Elastohydrodynamic Lubrication (DTEHL), Load Tooth Contact Analysis (LTCA), and system dynamics in a Closed Differential Herringbone Gear Transmission System (CDHGTS). Based on gear meshing theory, ring gear flexibility, and rough surface contact, a dynamic contact lubrication model is developed using thermoelastic fluid dynamic lubrication theory. A gear heat transfer model integrating heat transfer and flexible deformation is established to capture dynamic thermal variations at each ring gear node. By coupling the DTEHL model, heat transfer model, and LTCA model, a nonlinear dynamic model incorporating flexible-tribo coupling is constructed. The nonlinear dynamic response of the CDHGTS under DTEHL conditions is analyzed, focusing on the influence of ring gear flexibility on system vibration. Furthermore, nonlinear dynamic behavior induced by ring gear flexibility, friction coefficient, and damping coefficient is examined. The proposed model is validated through bench vibration experiments. The study refines dynamic modeling and analysis methods for herringbone gears, offering theoretical guidance for evaluating the impact of coupled engineering factors on gear dynamics.