"Mini Air 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. Belong to rolling friction ball bearing rolling of metal beads, small contact surface, the friction coefficient is small; and oil-bearing "Mini Air Cooling Fan" for sliding friction, a large contact surface, after long-term use, the oil will be volatile, bearing easy to wear, friction coefficient big, big noise late, short life. Oil-bearing fan used copper-based sintered powder made by using the oil-bearing "Mini Air Cooling Fan" need to add oil to reduce the number of sliding friction, by lithium grease lubricating oil system Stuttgart modulation.