Rolling bearing life depends on the contact stresses that occur between the rolling elements and the raceways. Contact stresses are calculated from contact loads, which in turn depend on the external loads acting on the bearing and the precise internal geometry of the bearing.
The main function of rolling bearings is to support load and transmit rotational movement with minimum energy loss. In order to achieve this, bearings are manufactured with particularly good quality fatigue resistance materials, proper design and tight manufacturing tolerances. Particular emphasis is put in both the macro, and micro geometry of the working shapes and surfaces of the raceways. Rolling bearings come in many types and sizes as ball and roller bearings for radial and thrust loads.