ABSTRACT
Getting wisdom is the most important thing you can do! And whatever else you do, get good judgment.
Proverbs 4:7
This chapter focuses on bearings that are conformal in their geometry, with a lubricant interspersed between the surfaces. There are two basic types of bearings considered in this chapter: hydrodynamic bearings, where the pressure generated in a lubricant film is caused by viscosity and bearing motion, and hydrostatic, where the pressure is produced by some external (pumping) means. Such bearings have the typical characteristics of very low friction, high efficiency and reliability, and very good load support. The main drawbacks to these bearings are their larger size compared to rolling element bearings, high startup friction, and the need to consider thermal effects on the lubricant. Wear is very low, and generally occurs only during startup. Building upon the information in Chapter 8, this chapter begins with an in-depth analysis of the fluid mechanics involved in such bearings by presenting the Reynolds equation and investigating all of its terms. Application of the Reynolds equation to thrust bearings is then followed by presentation of numerical results. The unique geometry, boundary conditions, and pressure profile in journal bearings are then discussed, and numerical solutions and design charts are presented and demonstrated. Finally, squeeze film and hydrostatic bearings are analyzed.
