Fluid Film Bearing Design Considerations

Abstract

The basic and practical design concepts of fluid film bearings as applied to turbomachinery will be discussed. The discussion will cover specific applications that are representative of a wide range of conditions that can be expected. This will include the types of bearings that are most indicated for the specific machinery and their operating conditions. Although the basic theoretical criteria will be included, the emphasis will be on "hardware" examples that describe tile bearing design for the particular job, speed, and type of fluid lubricant and temperature will basically categorize the design applications. Applications will cover speeds ranging as high as 100.000 rpm. The use of lubricants that are the process fluids result in simplicity of over-all design and are, in many cases, quite feasible. The fluid lubricants covered will be, the conventional oils, the low viscosity liquids such as water, Mercury, etc., and gases such as air. The discussion will give the designer a feel for the type of bearing most applicable, and information to ballpark the size. Additional influencing factors such as alignment, and the types and effect of shaft and bearing instabilities will be discussed.