(1) bad "Mini Air Cooling Fan" lubricating quality. Lubrication aim is not to make direct contact with the movement part of the friction, and the formation of friction between solids and liquids. If the number of inadequate or poor quality lubricants, static and dynamic part of the direct causes friction and heat, or heat can not be taken away by the lubricating oil, leaving the bearing temperature.
(2) poor quality of the rolling bearing assembly. Such as the inner sleeve and the shaft clamping force is not enough, jackets and bearing clearance is too large or too small.
(3) "Mini Air Cooling Fan" bearing vibration is too large to withstand shock loads, seriously affect the stability of the lubricant film.
(4) felt tight seal and heat.
(5) "Mini Air Cooling Fan" poor quality bearings. Bearing scraping poor quality, Ugyen bad contact or bodiless; Rolling rolling decent cracks, chipping, peeling, etc., will undermine the stability and uniformity of the film, the surface of the bearing heat.