Bearings introduction and application
A bearing is a mechanical element that limits relative motion to only the desired motion and at the same time it reduces the frictional resistance to the desired motion. Depending on the design of the bearing, it may allow free rotation around a fixed axis (such as the case of shafts) or free linear movement, or both in some cases.
Bearings may be classified according to the type of operation, the motions allowed, or to the directions of the loads applied to the parts. The most broad classification of bearings is according to the type of operation where they are classified in two groups;
• Rolling-contact bearings
• Sliding-contact bearings