Influence of Sulfur-Phosphorus Additive Interaction Effects on the Performance of Roller Bearing Greases

Friction wear is inevitable in roller bearings at high speeds, under heavy loads and vibration, and in other operating conditions. The use of grease can significantly reduce frictional wear. Sulfur–phosphorus additives have excellent anti-wear properties, oxidation resistance, and stability under high load and high-speed conditions. Their application in roller bearings enhances the performance of the grease, thus ensuring the normal operation of roller bearings. This study focuses on the effect of interaction between sulfur–phosphorus additives. Using a friction and wear tester and a rotational rheometer, the original roller bearing grease Fuchs 585k plus was used as the original grease, and the original grease was blended with MoS2, MoS2+TBP, and MoS2+T321, respectively, to comparatively analyze the effect of sulfur–phosphorus additives and their interaction effect on the tribological and rheological properties of the roller bearing grease. The results show that the addition of all the above three additives can improve the anti-wear performance and anti-shear performance of roller bearing grease. Among them, the most significant optimization effect is MoS2+T321, followed by MoS2, and finally MoS2+TBP. This result provides a new idea for the performance enhancement and formulation optimization of roller bearing grease.