A ball bearing is a low-capacity rolling element that utilizes balls to maintain a unique space between two parts of a rotating system. Ball bearings consist of four main parts. An outer ring, a smaller inner ring, steel balls rolling between the rings, and a cage-like part that keeps the steel balls from banging together during rotation. This structure is so precise and efficient that it has been used for over 500 years.
Ball bearings are used to reduce friction during rotation and support various loads. It does this by using two or more tracks to accommodate the balls and transfer the weight of the load through the balls. Typically, one track sits in the hole and remains stationary while the other track is fixed in the rotating part. The system works simply because if the shaft is set on a rolling unit as opposed to freely rotating, there is less friction, allowing the surfaces to slide against each other.
Ball bearings come in a wide range of sizes, from components the size of rice used to run watches, to devices the size of industrial motors in warehouse machinery or airplanes. Regardless of size, ball bearings work in exactly the same way and are an undeniably important feature in day-to-day operation. Ball bearings are needed in everything from clocks and disk drives to fans, air conditioning units and car axles. In fact, anything with a motor, no matter how big or small, can be kept in smooth, working order with the help of ball bearings.