The basic structure of the bearing consists of four parts: the inner ring, the outer ring, the rolling elements (steel balls or rollers) and the cage.
1. Inner ring (also known as inner sleeve or inner ring): usually fixed on the journal, the inner ring rotates with the shaft. The outer surface of the inner ring has a groove for rolling a steel ball or a roller, which is called an inner groove or an inner race.
2, the outer ring (also known as the outer casing or outer ring): usually fixed on the housing of the bearing or the machine, to support the role of rolling elements. There are also grooves on the inner surface of the outer ring for the rolling of steel balls or rollers, called inner grooves or inner races.
3. Rolling body (steel ball or roller): Each set of bearings is equipped with one or several sets of rolling elements, which are installed between the inner ring and the outer ring, and play the role of rolling each transmission force. Rolling elements are load-bearing parts whose shape, size and number determine the ability of the bearing to withstand loads at high speeds.
4. Cage (also known as retainer or isolator): The rolling elements in the bearing are evenly spaced from each other so that each rolling element rolls normally between the inner ring and the outer ring.