有限长线接触副脂润滑成膜性能研究

Study on Film-forming Ability in Finite Line Contact with Grease Lubrication

以润滑脂为润滑介质,采用Herschel-Bulkley模型,建立有限长线接触脂润滑的弹流模型,并验证该模型的正确性。分析润滑脂的流变特性对成膜能力的影响,包括流变指数、塑性黏度和屈服剪切应力。结果表明,随着流变指数的增加,油膜厚度增加,油膜压力基本不变;随着塑性黏度的增加,滚子中部油膜厚度显著增加,无油膜的塞流层宽度减小;屈服剪切应力对油膜压力以及油膜厚度影响很小,但随着屈服剪切应力的增加,塞流层的区域增加。

Based on the Herschel-Bulkley model,a finite line contact elastohydrodynamic lubrication model was set up and validated by the calculation results in the literature. The effect of the rheological properties of grease on the film-forming ability was studied,including rheological index,plastic viscosity and yield shear stress. The results show that with the increasing of rheological index,the film thickness is increased,while the oil film pressure usually keeps steady. The oil film thickness in the middle of the roller is increased significantly with the increasing of plastic viscosity,while the width of settled layer is decreased in the condition of non-oil film. The yield shear stress has little impact on film stress and film thickness. However,the area of settled layer is increased with the increasing of yield shear stress.