Today "Tiny Cooling Fan" in order to reduce noise have put some designs, such as changing the angle of the blades, increasing lubricity and stability of the fan shaft and so on. We use lubricating bearings, since the running time is not long it is easy to cause the machine to overheat and crash phenomenon, severe cases may also burn out the movement. For this reason, there are many good brands of "Tiny Cooling Fan" are beginning to use the ball, which is to use a lot of ball bearings to reduce friction as the media. This ball bearing cooling fan is characterized by wind, long life, low noise, but the cost is relatively high, but, it is possible to use only high-grade fan to it, but for the ordinary "Tiny Cooling Fan", although called "bearing "but just bush bearing, that is, from the copper jacket and steel shaft core component, and the" ball "But the heat completely different. In addition, the author would like to stress here that it is, to have a smooth rotation of the cooling fan, or is prone to noise, so we in the purchase of "Tiny Cooling Fan", must also remember to check the fan roller axis is loose.