A world without bearings would look far different. Although rarely noticed, bearings are ubiquitous: computers have a few, electric appliances contain several, and an automobile has hundreds. Without bearings, much of the motion that is taken for granted would not be possible.

Since the first wheel was invented, people understood that it takes less effort to move an object on rollers than to simply slide it over a surface. People later discovered that lubrication also reduces the effort to side objects. Bearings combine these two basic findings to provide rolling motion necessary for things as simple as a tiny in-line skate wheel and as complex and large as a steam turbine. Bearings save energy, which is otherwise required to counteract friction arising from any elements related rotation, the better the bearing, the greater the energy savings.

Types of Bearings

Bearings can be divided into rolling element bearings and...