Abstract Grease lubrication is widely used in rolling element bearing because of its special rheological characteristics. Available studies are mainly based on experiments, while the relevant numerical studies of grease are quite limited. The purpose of this article is to establish a mixed elastohydrodynamic lubrication (EHL) model in point contact based on the rheological model of grease, which can calculate film thickness distribution applied to smooth and roughness surface. The obtained result is compared with that of it operated only in base oil. Besides, the impacts of load, surface roughness and rheological parameters on the grease film thickness have been investigated. In addition, the Stribeck curves of four greases covering different base oil viscosity and thickener types were measured on a ball-on-disc device, which can ensure that the contact area was in full film lubrication. From the study, it is concluded that the obtained grease friction behavior agrees well with the variation of grease film thickness calculated by the present mixed EHL model.

中文翻译：

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考虑表面粗糙度的油脂润滑混合 EHL 模型和摩擦行为研究

摘要 油脂润滑因其特殊的流变特性而被广泛应用于滚动轴承。现有的研究主要基于实验，而对润滑脂的相关数值研究非常有限。本文的目的是在润滑脂流变模型的基础上建立点接触的混合弹性流体动力润滑（EHL）模型，该模型可以计算适用于光滑和粗糙表面的油膜厚度分布。将所得结果与仅在基础油中操作的结果进行比较。此外，还研究了载荷、表面粗糙度和流变参数对润滑脂膜厚度的影响。此外，涵盖不同基础油粘度和增稠剂类型的四种润滑脂的 St​​ribeck 曲线是在球盘装置上测量的，可以保证接触区域处于全油膜润滑状态。从研究中得出的结论是，获得的润滑脂摩擦行为与现有混合 EHL 模型计算的润滑脂膜厚度的变化非常吻合。