"220V Cooling Fan" use of oil-bearing copper-based sintered powder made by using lubricating oil bearings need to reduce the number of sliding friction, by lithium grease lubricating oil system Stuttgart modulation. With the long run, the oil inside the bearing will evaporate and dry, the friction coefficient increases, fan operation affected may appear different sound, speed Pianman not even turn on. The "220V Cooling Fan" ball bearing rolling friction by replacing sliding friction, low coefficient of friction and to overcome the shortcomings of the friction coefficient is apt, therefore running stability, life is relatively much longer. "220V Cooling Fan" bearing system generally recommend the best selection of ball bearings, fan heat fan because life often depends on the reliability of its bearings, ball bearing system has been shown to have the characteristics of high efficiency and low heat generation.