Common bearing cooling fan are: ball bearings, oil bearing, magnetic bearings.
Ball bearing
Ball Bearings (Ball Bearing) has changed the way of bearing friction, rolling friction, two balls or hoops middle of some steel columns, supported by some of the grease. This approach is more effective in reducing the friction between the bearing surface phenomenon, effectively raising the fan bearing life, and therefore the heat sink is reduced, longer life. The disadvantage is brought about by a more complex process, which will raise costs, it also brings higher operating noise.
Oil-bearing
Oil bearing (Sleeve Bearing)) is the use of sliding friction sleeve bearings, use of lubricants as a lubricant and DRA. Can be said that the market is now the most common type of bearing technology, because of its low cost, simple to manufacture many products, including well-known brands are still in continuous use. The advantage is the use of the initial quiet, low noise, low price.
Magnetic Bearings
Magnetic bearing (Magnetic Bearing) motor using magnetic levitation (Magnetic System, MS) design is the use of magnetic force of the rotor is suspended in the air, so there is no mechanical contact between the rotor and the stator. The principle is that the magnetic flux lines and maglev line perpendicular to, the axis and the maglev line are parallel, so the weight of the rotor is fixed on the running track, the use of almost no load spool core to the opposite maglev line direction of the top support, form the entire rotor vacant, fixed running track. Compared with the traditional ball bearing, oil bearing, magnetic bearing no mechanical contact with the rotor can run into very high speed, mechanical wear, low energy consumption, low noise, long life, no lubrication, no oil pollution, etc. , especially for high-speed, vacuum, and other special clean environment. Maglev in fact only an auxiliary function, not form independent bearing, have specific applications in combination with other forms of bearings, such as ball bearings + maglev, maglev + oil bearing, magnetic bearings, etc. + vaporization.