Bearing application knowledge: computer cooling fan, reliability of the fan bearing system determines the service life of cooling fan and its noise and stability. Classification according to the fan bearings, air cooling radiator generally has two kinds: oil bearing and ball bearing fan. Oil bearing though cheap, but the oil bearing for sliding friction, large contact surface, the long-term use, the lubricating oil volatilization, bearing is easy to wear, friction coefficient, the late big noise, short service life. While the ball is rolling friction, has the features of high efficiency and low heat generation, the friction coefficient, low wear, so the service life is generally 40000 hours later, the noise is smaller. Along with the computer radiation volume increasing, oil bearing fan has obviously can not meet the demand of the computer radiation, ball fan has gradually become the mainstream of computer cooling fan. In bearing manufacturing process, the main part of the impact on the quality of the steel ball manufacturing, product selection, production process of cleaning, stainless steel materials used in aerospace industry and precision assembly etc.. The micro fan motor bearing, bearing the current domestic production of limited to technical reasons, can not meet the quality of high speed, high performance fan's request, after using the product performance is not just as one wishes. Even some of the illegal manufacturers, the so-called ball fan tend to choose the price and performance of waste bearing production as poor, a serious violation of the rights and interests of consumers. Only the outside to watch, high-quality bearings and shoddy bearings were not obvious, but the technical content of which both are unable to compare. The bearing preload as an example, the domestic manufacturers and international brand reflects the technical differences in the process. Preloading, refers to the ball is fixed to the bearing sleeve, the ball and the bearing sleeve surface tightly, no gap, so that the steel ball wear degree is the smallest. Usually make the domestic manufacturers in the bearing, preload on the bearing sleeve is opposite before, because the ball size and bearing sleeve size will certainly there are some errors, so the preloading force, a total clearance of 5-10 microns ball bearing is set between the coaxial, this gap, the aging degree of wear the bearing greatly increased, shortened service life. Similarly, in bearing manufacturing company NSK, pre pressure when the upper and lower bearings have a relative distance of about 5 microns, so the bearing sleeve in compression will be tightly jammed ball, so that the gap is reduced to zero, the fan, the ball will not beat, so wear to a minimum, to ensure smooth running and long fan. The production of the best fan, of course, to choose the best bearing. As a radiator brand well-known, Aeolus computer radiator from the listed at the beginning of the strict requirements, the application of high quality raw materials to ensure the products with high performance. Through the whole series high temperature of bearing of different manufactures all kinds of bearing aging experiment testing, selection and use, as early as in 1999, Aeolus has been officially identified with the world's largest precision bearings manufacturer -- NSK company of Japan imported cooperation. At present, the Aeolus series of computer radiator products are used NSK company imported ball bearing, from the fundamental guarantee for the quality of the fan.