A Rifle Bearing, abbreviated as RB, is a type of bearing used in fans. It is an improved variant of a simpler sleeve bearing. Its main component is a shaft with a milled helical groove, which acts as a pump when rotating. This groove pumps lubricant from the lower part of the bearing and distributes it along the entire length of the shaft, thereby ensuring constant and effective lubrication. Thanks to this mechanism, the bearing has a longer lifespan and is quieter than basic sleeve bearings, which suffer from faster lubricant drying. Compared to ball bearings, it offers quieter operation. Therefore, it is often used in fans within complete water cooling sets, where emphasis is placed on the balance between quiet operation and reliability.