We disassembled thirteen fans with fluid dynamic bearing to better understand what kind of bearing design they really use. You will be surprised to know that manufacturers use the same name for different things. Check it out.

Here is a snippet: "The fluid dynamic bearing (FDB) was first used in hard disk drives. It is a modification to the standard sleeve bearing to improve the lubrication of the bearing, and thus increase the life span of the fan while retaining one of the most positive aspects of sleeve bearing fans, which is the low noise level. However, what can be classified as fluid dynamic bearing is somewhat controversial, and designs vary greatly."



Link: Hardwaresecrets