渐开线斜齿轮传动摩擦动力学耦合研究

Coupling Research on Dynamical Behavior and Elastohydrodynamic Lubrication Property of Helical Gear

综合考虑时变啮合刚度、轴承刚度以及摩擦力等对动力学行为的影响,基于载荷分担理论和动力学、弹流润滑理论,建立12自由度斜齿轮摩擦动力学模型。采用解耦方法求解该摩擦动力学模型,将动力学求解获得的动态轮齿作用力用于润滑分析中,而润滑分析获得的摩擦因数再次用于动力学分析计算中。通过实例研究了齿面摩擦学特性和动力学行为以及两者之间的耦合关系。研究表明:考虑耦合效应后的斜齿轮动态响应与定摩擦因数下的动态响应相比有较大不同,且时变摩擦力对垂直于啮合线方向的动态响应影响尤为显著;动态载荷等对斜齿轮润滑特性影响较大,转速接近共振转速时,动态载荷作用下的油膜厚度、油膜承载比例、油膜温升和摩擦因数分布规律与幅值与稳态载荷相比差异明显。动态载荷对斜齿轮润滑特性以及时变滑动摩擦力对动态响应的影响不可忽略。

A twelve-degree-of-freedom tribo-dynamics model for helical gear pair is proposed based on load sharing theory,dynamics and elastohydrodynamic lubrication theory.Time-varying mesh stiffness,bearing stiffness,as well as the friction force are considered when establishing the model.A decoupling method of dynamics and tribology is proposed to solve the lubrication and dynamics models simultaneously.In the iterative loop,the dynamic model predicted the dynamic tooth forces to be used in the lubrication model.In return,the gear lubrication model is provided the dynamic model with periodic friction coefficient.An example gear pair is analyzed using the proposed model and method to demonstrate this coupling relationship between tribological and dynamic behaviors.The results show that the helical gear’s dynamic response with consideration of coupling effect is different from the dynamic response under the constant friction factor.Friction force has significant effect on dynamic response that’s perpendicular to action line.Dynamic load offects lubrication property greatly.Moreover,when the working rotational speed is approaching the resonance speed,compared with steady load,the distribution and amplitude of oil film thickness,portion of load carried by film,film temperature rise and the friction coefficient the oil film thickness is quite different.The influence of dynamic load on helical gear’s lubrication property can’t be ignored,so does the influence of time-varying sliding friction on dynamic response.