SATISFACTORY performance of a lubricant depends upon characteristics of the lubricant, operating conditions and design of the device in which the lubricant is used. Applied lubrication requires a study of the relation among these factors in their effect upon performance.
The authors treat journal bearings, ball and roller bearings and gears. Equations are given for journal bearings operating under various conditions of design, lubrication, friction and heat dissipation.
The authors conclude that neither ZN/P nor PV alone is adequate as a measure of the power dissipated by a bearing, a composite relation involving both terms being required over a large part of the operating range. They show that each bearing has a minimum value of ZN/P below which it may get into the unstable region of thin-film lubrication and fail.
Temperature rise in the oil film was studied and the recommendation is made that the metallic parts should be cooled, as by the use of an efficient oil-cooler and a system that will provide effective heat transfer from the metallic parts to the cooled oil.