5. Friction torque of roller or needle bearings and thrust bearings

Friction in a bearing generates heat, which affects the operating temperature. Total rolling resistance consists of friction:

• rolling in the rolling element/track contacts;

• sliding in the cage/rolling element contacts and cage on guide ring;

• viscosity of the lubricant;

• and seals in protected bearings.

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