plain bearing (in railroading sometimes called a solid bearing) is the simplest type of bearing, comprising
just a bearing surface and no rolling elements. Therefore the journal (i.e., the part of the shaft in
contact with the bearing) slides over the bearing surface. The simplest example of a plain bearing is a
shaft rotating in a hole. A simple linear bearing can be a pair of flat surfaces designed to allow motion;
e.g., a drawer and the slides it rests on or the ways on the bed of a lathe.
Plain bearings, in general, are the least expensive type of bearing. They are also compact and lightweight,
and they have a high load-carrying capacity.