旋转轴唇形密封混合润滑理论模型和试验验证

A Mixed Lubrication Theoretical Model and Experimental Verification of Rotary Lip Seals

基于旋转轴唇形密封的反向泵送机理,采用流量因子统计学方法同时考虑密封唇表面粗糙峰接触的影响进行唇封性能的理论分析,建立唇封的混合润滑模型,模型耦合考虑流体力学分析,粗糙峰接触力学分析以及变形分析。求解雷诺方程得出油膜压力和切应力,利用GREENWOOD-WILLIAMSON接触模型计算粗糙峰与轴之间的接触压力,采用影响系数法进行变形分析。基于所建立的混合润滑模型,结合一种典型的唇封结构,对评价唇封性能的泵送率和摩擦扭矩进行数值计算,并通过自主研制的台架试验验证了唇封混合润滑模型的正确性。由于表面粗糙峰是导致旋转轴唇形密封产生泵送效果的原因,利用验证的理论模型对粗糙度对泵送率、摩擦扭矩和接触面积的影响进行分析。

A mixed lubrication model of rotary lip seals using a statistical approach with flow factors based on reverse pumping mechanism has been developed. The model consists of coupled fluid mechanics analysis, asperity contact analysis and deformation analysis. The oil film pressure and shear stress are obtained from solving the Reynolds equation. Using the GREENWOOD- WILLIAMSON surface contact model computes the contact pressure between the lip and shaft. The deformation analysis of lip seals is carried out using the influence coefficient method. Applying the mixed lubrication model to a typical lip seal, the pumping rate and friction torque are the two most important factors of evaluating seal characteristics, which are the output results of theoretical simulation. Most important, the pumping rate and friction torque are measured with bench test designed by the authors. The measurement of these two factors verifies the validity of the mixed lubrication model. For the reverse pumping action of rotary lip seals is resulted from the surface asperities, the influence of roughness on the pumping rate, friction torque and the contact area are carried out by using the verified theoretical mixed lubrication modle.