Ball bearings

The term ball bearing includes the roller bearing, the type of ball bearing most frequently used in terms of quantity. The technically correct term is deep groove ball bearing. The balls are guided by deep grooves in the inner and outer race, with a narrow bevelling plane. The relatively small areas of contact between the balls and the raceway (point contact) make the rolling resistance very small. A cage keeps the balls apart and prevents them touching. This leads to relatively low-friction loads being transmitted between parts of a machine which move in relation to one another. The load transmission takes place between the ball and the inner or outer race. Modern ball bearings are assembled according to the Conrad method. 

To reduce rolling friction, deep groove ball bearings are usually lubricated by oil or grease. A lubricating film is formed during the rotational movement between ball and raceway, which prevents direct rolling contact (dry running). The lubricant has a significant influence on the reliability of a bearing. For this reason, modern roller bearings are filled with a suitable roller bearing grease in the factory. Cover or sealing plates which are fitted additionally to the narrow ends ensure that there is enough lubricant in the bearing and prevents soiling from the outside. This makes deep groove ball bearings maintenance-free for many applications. 

Experts distinguish between single-row and multi-row ball bearings depending on the number of ball rows. 

In addition, ball bearings are classified according to the raceway design into deep groove ball bearings, separable bearings, angular contact ball bearings, four point contact bearings and self-aligning ball bearings. 

The specialists at Wälzlagertechnik have a wide range of experience at their disposal for the optimum selection of ball bearing design, lubrication and sealing, so that the bearings can be optimised in terms of price, performance and service life for specific customer applications.