Rheological and Physical Studies of Lubricating Greases Before and After Use in Bearings

Abstract

Lithium soap and calcium complex soap-based lubricating greases are studied when fresh and after use in roller and ball bearings. Examination of the rheological properties of these greases using rotating rheometers reveals changes that have occurred during use in the bearings. These modifications are not uniform throughout the hearing. Physical and chemical analyses enable these modifications in rheological properties to be linked to variations in composition or structure, depending on the type of grease and bearing. Several mechanisms involved in lubricating a bearing with a lubricating grease are confirmed or clarified.