An analysis of the mechanisms of grease lubrication in rolling element bearings

There are over eighteen billion bearings in use in the world, and most are grease lubricated. Grease is chosen for a variety of reasons: it gives low friction, is easily confined, and has a long lubricating life at low cost. In many applications, the grease is expected to lubricate effectively over a wide range of conditions and for extended periods. For such applications, lubricant failure leads to instantaneous and rapidly increasing damage of the components and eventually breakdown. Thus, an improved understanding of the fundamental aspects of grease lubrication has far-ranging technical and economic implications. Despite the overwhelming importance of this subject, very little is known about the mechanisms of grease lubrication and the relationship between composition, lubrication performance, and life. This paper attempts to summarise current understanding of grease lubrication mechanisms in rolling element bearings and to consolidate the different aspects of this complex topic.

[1]  P. D. Fleischauer,et al.  Chemical Analysis of Hydrocarbon Grease from Spin Bearing Tests , 1983 .

[2]  A. Cameron,et al.  Optical Analysis of Ball Bearing Starvation , 1971 .

[3]  E. Kingsbury.  Parched Elastohydrodynamic Lubrication , 1985 .

[4]  Stephen E. Wiberley,et al.  Flow Properties of Lithium Stearate-Oil Model Greases as Functions of Soap Concentration and Temperature , 1960 .

[5]  B. Hamrock,et al.  Fundamentals of Fluid Film Lubrication , 1994 .

[6]  Jun Cheng.  Elastohydrodynamic Grease Lubrication Theory and Numerical Solution in Line Contacts , 1994 .

[7]  D. Zhu,et al.  Effect of Surface Roughness on the Point Contact EHL , 1988 .

[8]  J. A. Greenwood,et al.  Elastohydrodynamic Lubrication With Herschel-Bulkley Model Greases , 1972 .

[9]  Pressure distribution and shape of an elastohydro-dynamic grease film , 1979 .

[10]  Ito Hiroyuki,et al.  Grease Life Equations for Sealed Ball Bearings. , 1995 .

[11]  Henrik Åström,et al.  Lubricating Grease Replenishment in an Elastohydrodynamic Point Contact , 1993 .

[12]  Erik Höglund,et al.  Starting and Steady-State Friction Torque of Grease-Lubricated Rolling Element Bearings at Low Temperatures—Part II: Correlation with Less-Complex Test Methods , 1996 .

[13]  B. Williamson.  An Optical Study Of Grease Rheology in an Elastohydrodynamic Point Contact Under Fully Flooded and Starvation Conditions , 1995 .

[14]  D. Dong,et al.  A theory of elastohydrodynamic grease-lubricated line contact based on a refined rheological model , 1988 .

[15]  Henrik Åström,et al.  Video recordings of an EHD point contact lubricated with grease , 1991 .

[16]  Hugh Spikes,et al.  A study of parched lubrication , 1992 .

[17]  W. Jonkisz,et al.  The properties of elastohydrodynamic grease films , 1982 .

[18]  Hugh Spikes,et al.  Film thickness measurements of lubricating greases under normally starved conditions , 1992 .

[19]  Victoria Wikström,et al.  Rolling bearing lubrication at low temperature , 1996 .

[20]  Antonius Lubrecht,et al.  Track Depletion and Replenishment in a Grease Lubricated Point Contact: A Quantitative Analysis , 1997 .

[21]  Philippa Cann,et al.  Starvation and Reflow in a Grease-Lubricated Elastohydrodynamic Contact , 1996 .

[22]  R. H. Focke.  Multi-purpose greases: a new dimension , 1994 .

[23]  G. Dalmaz,et al.  Film Thickness in Starved EHL Point Contacts , 1998 .

[24]  P. Cann.  Grease lubricant film distribution in rolling contacts , 1997 .

[25]  Y. Chiu.  An Analysis and Prediction of Lubricant Film Starvation in Rolling Contact Systems , 1974 .