"AC Fan" by the rotor shaft, impeller, bearings, timing gears, couplings, bushings and the like. Impeller are optional involute surface, high volume applications. Near the end the choice of the coupling end of 3000 as a positioning double row spherical roller bearings. Near the gear end as a free end selection 32000 single row radial cylindrical roller bearings in order to adapt the axial displacement of the rotor thermal distention. Medium and small wind turbine equipped with common base, with a large fan only fan base means to facilitate debugging. Submerged gears, bearings splash smooth. Smooth result is good, safe and reliable. Blower body casing and is composed of left and right wall.