Rolling bearings are called anti-friction bearing. They have high loading capacity and exhibit very low rolling friction torques. The friction torques are similar or lower than ideally designed plain bearing operating under conditions of thick film lubrication. Rolling bearing has low starting torques.
The idling friction is depends on the quantity of lubricant, operating speed, viscosity of lubricant during operation, seal and operating conditions in which bearing is running.
The bearing friction torque Mr = F. f. (d/2) or
The bearing friction torque Mr = F. fm. (Dm/2)
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White Paper – Friction in Bearings