Effect of thermorheological properties on tribological behaviors of lubricating grease

Abstract

Lubricating grease has increased thermorheological properties during heating, which may affect the lubrication of the friction pair. And a friction pair usually heats up in the working process. This study explored the effect of surface temperature of the friction pair on the lubrication performance under lubrication conditions. The thermorheological properties of lubricating grease were analyzed using a rotational rheometer, and the variations and mechanisms of the thermo-rheological properties were explored. The friction-wear test on lubrication was conducted at different temperatures to examine the effects of thermorheological properties on the tribological behaviors of lubricating grease. Wear scar morphology, composition change, and friction-lubrication mechanisms at different temperatures were probed through SEM and X-ray spectrometer analysis. The results showed that lubricating grease has significant thermorheological properties. Moreover, its soap fiber entanglement decreases with rising temperature, and the entanglement properties are slowly lost at high temperature. The soap fiber structure of lubricating grease plays a vital role in lubrication. As temperature rises, the soap fiber entanglement of lubricating grease decreases and the base oil is more easily released under shear, exhibiting a trend of friction coefficient decreasing with the rising temperature. High temperatures weaken the soap fiber entanglement of lubricating grease, the film-forming property, and the surface friction-abrasion resistance of the friction pair and even cause oxidative wear.

Review of Wind Power Bearing Wear Analysis and Intelligent Lubrication Method Research

“…Meanwhile, the operating temperature of the bearings also varies with the temperature of the surrounding ambient medium [101]. Therefore, when selecting bearing grease, it is necessary to consider not only the dropping point temperature of the grease but also parameters such as the type of its base oil, antioxidant properties, and evaporation properties, as well as the influence brought about by the temperature of the ambient medium [102,103]. Table 2 below shows the selection of different types of grease according to the operating temperature of the bearings.…”

Synergistic lubrication effects of Sn–Ag–Cu and MXene–Ti3C2 to improve tribological properties of M50 bearing steel with microporous channels

“…The former is mainly to add texture to the material surface (Xue et al , 2021) or coat the contact surface (Holubets et al , 2020; Güler and Büyüklüolu, 2020). Changing the lubrication environment of materials mainly includes lubricating oil (Rudenko and Bandyopadhyay, 2013; Nuraliza and Syahrullail, 2016), grease (Pan et al , 2020; Laurentis et al , 2016) and solid lubricant (Yang et al , 2018; Huang et al , 2022a). Therefore, combining texture with solid lubricant to improve the tribological performances of M50 bearing steel is an important way to increase the fatigue life of the bearing.…”

Effect of magnetic field on the lubricating performance of nano magnetorheological grease at different temperatures

“…Thus, the internal soap fiber structure of the grease changes. The base oil is lost from the mesh structure, and lubrication failure occurs (Pan et al , 2022; Pan et al , 2021; Pan et al , 2020; Cortés-Triviño et al , 2019). Areas such as aerospace place required a wide range of service temperatures of lubricants.…”