WEAR REDUCTION SYSTEMS FOR COAL-FUELED DIESEL-ENGINES .1. THE BASICS OF POWDER LUBRICATION

The objective of this investigation is to resolve the problem of sever e wear occurring in systems using coal-water particulates as fuels or as a process material. The approach discussed herein consists of repla cing conventional oil lubrication with a powder lubrication system tha t uses the process particles, either alone or in combination with anot her powder. Unlike previous work in this field, this approach is based on the postulate of the quasi-hydrodynamic nature of powder lubricati on. This postulate is deduced from past observation and present verifi cation that there are a number of basic features of powder flow in nar row interfaces that have the characteristic behavior of fluid film lub rication. In addition to corroborating the basic mechanism of powder l ubrication, the conceptual and experimental work performed in this inv estigation provide guidelines for selection of the proper geometries, materials, and powders suitable for this tribological process. The pre sent investigation describes the fundamentals of quasi-hydrodynamic po wder lubrication and defines the rationale underlying the design of th e test facility. A follow-up paper dealing with the performance and th e results of the experimental investigation presents conclusions reach ed regarding design requirements as well as the formulation of a prope r model of quasi-hydrodynamic powder lubrication.