The fan for the transformer is mainly used for cooling systems such as outdoor ventilation. The fan comprises a motor, an impeller, a support frame and a mounting bracket.
Axial Fan For Transformer
The impeller is composed of a hub and a blade. The impeller, the blade and the attachment block are all formed by a special stretching die, and the blade is designed such that the root portion is curved along the height toward the air inlet. Tilting, the root of the blade is forwardly swept non-linearly along the height in the direction of rotation, forming a plate surface type with an attachment block at the root of the blade. Since the wheel hub, the blade and the attachment block are all made of thin steel plate, they are formed once by a special mold, and no turning processing is required, so that the weight of the impeller is uniform, thereby ensuring the balance precision of the fan. It also shortens the time of molded products and improves production efficiency. The blade and the hub are fastened by welding, one is convenient for manufacturing and reduces cost, and the other is to strengthen the stability of the fan. The axial fan noise is reduced, the fan flow rate and the differential pressure are increased.
Figure 1 is a schematic view of the structure of the fan;
Figure 2 is a side view of the structure of the fan impeller;
Figure 3 is a schematic view of the coupling of the blade and the hub.
As shown in Fig. 1, the fan is an axial flow fan for a transformer, and includes a motor 1, an impeller 3, a support frame 2, and a mounting bracket 4. The impeller is welded by the hub 5 and the blade 6, and the hub and the blade of the impeller are dedicated. drawing die for molding the root of the blade is designed to press forward along the height of the curve law inlet direction, along the height of the blade root law nonlinear swept forward rotational direction, into the board type, there is a block 7 attached to the blade root.
As shown in Fig. 2, when designing the fan blade, the smaller the hub ratio d(D/d) = 0.45, the efficiency of the axial flow fan can be improved; when the blade structure is designed, the root portion is oriented along the height toward the air inlet. According to the curve law, it is inclined forward by 30°, and the root of the blade is forwardly swept by 15° along the height of the rotation direction, so that the blade forms a forward-sloping and forward-swept plate surface type to reduce the noise of the axial flow ventilation surface and increase the fan. Wind pressure and air volume; the pre-pitch angle is the best angle, and the performance of the fan will be the best at this angle. Due to the high rotational speed of the fan, in order to increase the strength of the blade, an attachment block is welded to the root of the blade. As shown in Figure 3, the blades and hub of the impeller are connected by a tight weld.