点接触弹流摩擦副动特性研究

弹流油膜具有显著的弹簧、阻尼特性，对高副机械零件和系统的动特性具有重要影响。研究弹流摩擦副的动特性，揭示弹流摩擦副动力学特性的变化规律，对改进和提升整个机械系统的动力学设计具有重要意义。基于弹流润滑理论和机械振动学，建立点接触弹流摩擦副的摩擦学-动力学耦合模型，采用数值方法求解弹流摩擦副在简谐激励下的振动响应；通过简谐激励下弹流摩擦副的阻尼环识别出弹流摩擦副的刚度和阻尼，用参数控制的方法研究载荷、速度、材料参数及椭圆度等对弹流摩擦副刚度和阻尼的影响。结果表明：在研究的速度和载荷范围内，摩擦副的刚度和阻尼随载荷和椭圆度的增大而增大，随速度和材料参数的增大而减小，其中载荷对点接触EHL摩擦副的刚度和阻尼的影响最为显著，相比阻尼，摩擦副的刚度随载荷、速度和材料参数的变化幅度要大得多。在数值算例的基础上，给出弹流摩擦副的刚度和阻尼关于载荷、速度和材料参数的拟合公式。数值比较结果表明，给出的拟合公式具有满意的精度，可快速计算弹流状态下点接触摩擦副的刚度和阻尼。

On the Dynamic Characteristics of Point Contact EHL Friction Pairs

Elastohydrodynamic lubrication (EHL) oil film has remarkable elasticity and damping characteristics,which has great impact on the dynamic characteristics of higher pair contact mechanical elements and mechanical systems.Studying the dynamic characteristics of EHL friction pairs and revealing its change rules are of great significance for improving the dynamic design of whole mechanical system.Based on the EHL theory and mechanical vibration theory,the tribo-dynamics coupling model of point contact EHL friction pairs was established.The vibration response of the EHL friction pairs under harmonic excitation was solved by numerical method,the stiffness and damping of the EHL friction pair were identified by the response hysteresis loop of the EHL friction pair.The influence of load,speed and material parameters on the stiffness and damping of the EHL friction pairs was studied by parameter control method.The results show that,within the speed and load range studied,the stiffness and damping of friction pairs increase with the increase of load and ellipticity, and decrease with the increase of velocity and material parameters.The influence of load on stiffness and damping of point-contact EHL friction pair is most significant,the stiffness of friction pair varies significantly with load,velocity and material parameters compared with damping.On the basis of numerical examples,the fitting formulas of the stiffness and damping of the EHL friction pairs with respect to load,speed and material parameters were proposed.The results of numerical comparison show that the fitting formulas proposed have satisfactory accuracy,which can quickly calculate the stiffness and damping of point contact friction pairs under EHL conditions.