deep groove ball bearing

Everyday experiences demonstrate that rolling resistance is much less than sliding resistance. This principle is used in the rolling-element bearing which has found wide use. In the development of the automobile, ball and roller bearings were found to be ideal for many applications, and today they are widely used in almost every kind of machinery. These bearings are characterized by balls or cylinders confined between outer and inner rings. The balls or rollers are usually spaced uniformly by a cage or separator. The rolling elements are the most important because they transmit the loads from the moving parts of the machine to the stationary supports. Balls are uniformly spherical, but the rollers may be straight cylinders, or they may be barrel- or cone-shaped or of other forms, depending upon the purpose of the design. The rings, called the races, supply smooth, hard, accurate surfaces for the balls or rollers to roll on. Some types of ball and roller bearings are made without separators. In other types there is only the inner or the outer ring, and the rollers operate directly upon a suitably hardened and ground shaft or housing. Figure 5 shows a typical deep-grooved ball bearing, with the parts that are generally used.