Ageing Evaluation of No.2 Lithium Lubricating Grease

Contamination, acid number, moisture, thickness and dropping point are summarized as ageing indexes of lubricating grease. Size distribution, composition and weight of contamination which influence lubricating performance most and are used to evaluate performance of lubricating grease broadly in No.2 lithium lubricating grease which is used in main clutchs release ring of a certain type vehicle were analyzed after a vehicle which had run for about 20000 kilometers. Results showed that, the number of large size particle (larger than 25 μm) in aged grease was much larger than that in fresh grease, concentration of element Fe, Cr, Ni, Si, P, Ti, Mo, V, Na, Ca in aged grease was much higher than that in fresh grease, weight percentage contamination occupied in aged grease was very higher.