Synthesis of Lithium and Calcium complex greases delivering hightemperatureperformance for high-speed bearings

Grease is a gel-like lubricant that has different types due to a variety of applications. High temperatureperformance for high speed bearing is considered. For this demand we need to synthesize a greasewith a high dropping point and low viscosity. So we have prepared four samples, which are Lithiumsimple(۱) and complex(۲), Calcium simple(۳) and complex(۴) greases, using sebacic acid ascomplexing agent, to achieve that goal. The dropping points of samples are ۱۹۰, ۲۵۰, ۱۴۸ and ۲۵۰℃,respectively. The viscosity test has indicated that Lithium greases, either complex or simple, are moreviscose in a temperature range of ۸۰℃ to ۱۸۰℃ with a shear rate of ۵۰ s-۱. This was expected becausethe fiber length in Lithium soap is much longer than Calcium soap, and this causes an increase inviscosity in comparison. The amount of viscosity for samples with a shear rate of ۵۰ at initial andfinal temperatures of ۸۰℃ and ۱۸۰℃ is reported as follows: ۵۳۷۰-۳۲۴۰, ۶۴۰۰- ۳۹۰۰, ۴۷۵-۹, ۱۲۰۰-۲۵۵ mPa.s, respectively.

کلیدواژه ها:

Gel ، complex grease ، viscosity ، high speed ، high temperature grease ، fiber length