PC fans have been and continue to be decisive for many users, especially those looking for the best performance and sound. One of the most used types are the so-called FDB or Fluid Dynamic Bearing fans, translated as fluid dynamic bearing, of which several types have been manufactured based on the basis designed by Panasonic, but which are the best currently?
Before starting to break down the types you have to clarify something. Within the FDB designs there was great controversy because many manufacturers refused to pay the royalties to Matsushita , a Panasonic subsidiary at the time.
So they investigated based on the same principles and designed up to four versions that, legally, cannot be FDB bearings, but that as they share principles are included within them.
Still, the main story behind these bearings starts with hard drives, where Nidec has the patented initial design, and then ended up driving fans for their obvious advantages.
Types of FDB bearings
FDB Rifle Bearing
It is widely used by brands such as BitFenix or Arctic, where it starts with the premise that the bearing interior is largely smooth. One could speak of two types of design within this type of bearing, since some have a grooved design on the outside, while others like the one in the image above work with grooves that allow the fluid to do its job.
The interior design also plays a fundamental role, since the fluid will follow the direction of the internal grooves and will press against the walls of the same by pure rotation of the axis, which prevents the two metals from colliding with each other and generating friction.
FDB Bearing Groove
Also called a groove design because of the way the fluid moves. It has two different systems: the interior and the exterior, but both work in the same way.
Due to the twist, the liquid flows through the grooves to all parts of the walls, maximizing the pressure of the same against the walls and allowing there never to be a metal-to-metal collision. Some bearings can be completely smooth inside, something that loses a little effectiveness to the shaft when turning.
Bearing Groove little
It is based on the normal Groove, except that it only includes a vertical slot on the outside, the interior being completely smooth. It is a very basic type of bearing and could hardly be considered FDB, because its design leaves much to be desired, however much it includes a liquid on its walls and interior.
Obviously, among the fluid bearing designs, it is the cheapest to manufacture and the least optimal in terms of useful life and noise.
HDB
They are somewhere in the middle between FDBs and their own category, as they are listed as hydrodynamic, but they really follow the principle of fluids. They are therefore the most advanced and except in high-end models we will not see them as well.
They have both inside and outside triangular grooves that, as in the Grooves, focus the flow and pressure at the end point of the drawing, making the liquid remain as a lubricant between it and the walls of the engine.
It is the most aggressive and expensive design to manufacture, but it also achieves the best results. At the same time, it is the most faithful to the original Panasonic design, except that its technology has been carried within the same bearing.