4. Ball bearing friction

Friction in a bearing generates heat, which determines the operating temperature. Total rolling resistance is made up of :

• rolling friction in ball/track contacts,

• sliding friction in cage/ball and cage/guide ring contacts,

• viscous friction of the lubricant,

• and seal friction in protected bearings.

In the 1930s and 1940s, Palmgren established semi-empirical expressions for bearing friction torque. .