Bearings are the part that supports the rotating shaft. They are used in various types of machine including engines, and almost always used when there are rotating parts inside a machine.
Bearing contribute by rotating the shaft smoothly, preventing energy loss through friction, and reducing heating which, without the bearings, would lead to engine failure. It is said that bearings are such an important part as they can affect a machine’s performance. Bearings can be classified as either rolling bearings or sliding bearings.
Rolling bearings, often called ball bearings, use balls to rotate the shaft smoothly. Sliding bearings, often called plain bearings, use a lubricant such as oil between the bearing and the shaft, and this oil helps the shaft to rotate smoothly.
Daido Metal is a manufacturer of plain bearings.

Sliding and Rolling Bearings where plain bearing are used