Performance of Powder-Lubricated Journal Bearings With MoS2 Powder: Experimental Study of Thermal Phenomena

Abstract

Powder-lubricated, quasi-hydrodynamic journal bearings assist in controlling wear and hold promise for integration in outer space systems/mechanisms and in other hostile-environment applications where the use of conventional lubricants is impractical. Described herein are the thermal phenomena and an assessment of the thermal stability, heat generation and dissipation characteristics of slider-type, powder-lubricated bearings. Powder lubricant films provide lift and separate bearing surfaces and cause side leakage. The reduction in friction coefficient and, consequently, in the heat generated in the bearings, drastically reduces wear of the tribomaterials. Further, bearing side leakage carries away most of the heat generated by shear, reducing the heat to the critical bearing surfaces. Also presented are the thermohydrodynamic effects of powder lubrication (MoS2) on bearing performance criteria, e.g., temperature and friction coefficient as a function of speed and load, including the effect of powder flow rate on bearing performance and wear.