Preload usually increases the friction torque of the bearing because it eliminates radial and axial clearance, resulting in greater resistance when the bearing is running.
The role of preload is to eliminate radial and axial clearance inside the bearing, thereby improving the rigidity and precision of the bearing. However, this clearance elimination measure also increases the friction torque because the preload makes the contact between the internal parts of the bearing closer, thereby increasing the friction.
The magnitude of the friction torque is affected by several factors, including preload, operating speed, seals and lubricant amount. The initial torque is usually twice the friction torque. In addition, thermal expansion and internal fit (such as radial clearance) also affect the friction torque.
In order to reduce the friction torque, you can consider using a low-friction running design of the bearing during design, and optimize the amount of lubricant used and the seal design to reduce friction and resistance. In addition, choosing the right cleaning fluid and cleaning method to ensure that the working surface is clean and free of foreign matter can also effectively reduce the friction torque.
