Ball bearings in "Micro Cooling Fan" application. Ball bearing is a rolling bearing, spherical steel beads attached to the inner and outer rims of intermediate steel ring, a rolling power transmission to reduce friction and improve the process of mechanical power transmission efficiency. Ball can not afford a large heavy loads, more common in light industry machinery. Ball is also called ball bearings. "Micro Cooling Fan" ball is the use of metal beads round operation, are the point of contact, so the operation is very easy to activate. Coupled with the use of ball bearings with the spring, so the spring top propped outside Ball Bearing metal ring, leaving the entire "Micro Cooling Fan" weight of the rotor blades is located on the ball, and is propped by the spring indirectly top, so It can be used in different directions, the angle of the portable products, but still prevent the fall, in order to avoid damage to the ball bearing, causing noise generation and life impairment.