At present, we know that there are two main ways of heat dissipation:water cooling and air cooling. However, due to factors such as cost and installation operation, the main position of air cooling is self-evident. However, whenever you encounter the annoying noise of the radiator in a dry winter, you should know why the noise of the radiator fan is becoming more and more obvious. Come on, let's get closer to the bearing world of the cooling fan.

First of all, there are many factors that determine the noise level of the fan, including rotating speed, fan blade size, fan dynamic balance, and user's noise environment. However, the most important factor is the bearing inside the fan. The bearings are divided into the following types:

oil-retaining bearing

          The oil bearing is the most commonly used cooling fan bearing at present. It uses lubricating oil as lubricant and drag reducer, and is suitable for low-speed fans and fans of small size ( less than 9 cm ), and usually has a life of 5000-8000 hours. The price is very low, the bearing is easy to wear and tear, the service life is short, the lubricating oil in the bearing sleeve is easy to leak out, the noise increases, and the main board and other accessories will be polluted.

hydraulic bearing

          Hydraulic bearing was originally initiated by AVC and was improved on the basis of oil bearing. The hydraulic bearing adopts a unique annular oil supply circuit, which greatly reduces the problem of oil leakage and greatly prolongs its service life to 40000 hours compared with the common oil bearing and inherits the advantages of the oil bearing. Is the current mainstream bearing technology, bearing type fans have a high proportion in the current radiator market. Longer life, lower noise and lower price than oil bearing, but oil leakage still exists.

Double ball bearing

          The dual ball bearing ( dual ball bearing or two ball bearing ) uses two ball bearings, in which there are several tiny steel balls around the axle center.When the fan or axle center rotates, the steel balls will rotate with each other, because they are all spheres, so the friction force is small and there is no problem of oil leakage. The service life has reached 50,000 to 100,000 hours. Good sealing property, long service life, but high cost and high noise ( because the friction point of ball bearing has increased 2 times ).

          Double ball bearings are relatively high-grade bearings, and nearly all large-diameter fans of 5000 rpm grade use double ball bearings. Therefore, we can see that high-end video cards generally focus on the use of double ball bearings. In fact, this kind of bearing is generally used in the radiator of the video card, so it can be used as a performance reference for consumers to choose.

Single ball bearing

          One ball bearing or ball + sleeveless bearing is an improvement on the traditional oil bearing, which uses a combination of sliding friction and rolling friction to reduce the cost of double ball bearings with one ball bearing and one oil bearing. Its rotor and stator are lubricated with balls and lubricated with lubricating oil, and its service life has reached 40000 hours. Overcomes the problems of short service life, unstable operation and low cost of the oil seal bearing. Noise is higher than oil seal bearing, but lower than double ball bearing.

          Through the above comparison, we can see that the oil-bearing is increasingly abandoned by famous factories because of its short service life and the direct influence of oil control inside the bearing on the noise level during operation. Double ball bearings are now widely favored by the industry and become the first choice for high-quality radiator fans.The running stability is not equal to the right, but the price is also higher. As a good and cheap choice, the compromise solution of each major manufacturer is to use single ball bearing.