Large axial flow impeller

Abstract

The invention relates to the technical field of large axial flow fans, in particular to a large axial flow impeller, which includes a hub, blade joints and blades. Composed of bolts, the mounting seat includes an upper mounting seat and a lower mounting seat. The lower end of the bushing is fixedly connected to the lower plate through the bushing flange, and the upper end is fixedly connected to the upper plate through the bushing flange. The centers of the lower mounting seat and the upper mounting seat correspond to each other. There are grooves for blade joints, fixed screw holes are provided on the mounting seat, and fastening through holes are respectively provided for the corresponding fixing screw holes of the upper plate and the lower plate. There is an installation gap between them. The width of the installation gap is larger than the width of the installation seat. There are installation screw holes between the two adjacent fixed screw holes on the installation seat. The installation screw holes are arranged along the circumference of the lower plate. The lower plate is provided with installation through holes correspondingly, and the mounting seat is fixedly connected with the lower plate through the mounting bolts passing through the mounting screw holes. It has the advantages of simple structure, high bending strength, light weight, convenient installation, safety and reliability, and low cost.

Description

technical field [0001] The utility model relates to the technical field of a large axial flow fan, in particular to a large axial flow impeller for a large axial flow fan. Background technique [0002] At present, the impeller of the existing large-scale axial flow fan is composed of blades, blade joints and hubs. There are usually two types of hubs. One kind of hub is provided with circular ribs on the outer edge, and the thickness of the circular ribs is usually 40-50mm. , with a diameter of about 1500mm, there is a mounting seat for the blade joint on the end face of the reinforcing rib, the blade is stuck in the groove on the mounting seat through the blade joint and fixedly connected to the reinforcing rib through the mounting seat through the U-shaped bolt, its advantages It is: easy to install, and its disadvantages are: the hub is bulky, high in cost, and insufficient in bending strength; the other hub is composed of an upper plate, a lower plate, a bushing, a bushin...

AI Technical Summary

Problems solved by technology

[0002] At present, the impeller of the existing large-scale axial flow fan is composed of blades, blade joints and hubs. There are usually two types of hubs. One kind of hub is provided with circular ribs on the outer edge, and the thickness of the circular ribs is usually 40-50mm. , with a diameter of about 1500mm, there is a mounting seat for the blade joint on the end face of the reinforcing rib, the blade is stuck in the groove on the mounting seat through the blade joint and fixedly connected to the reinforcing rib through the mounting seat through the U-shaped bolt, its advantages It is: easy to install, and its disadvantages are: the hub is bulky, high in cost, and insufficient in bending strength; the other hub is composed of an upper plate, a lower plate, a bushing, a bushing flange, a mounting seat and a fixing bolt, and the mounting seat includes The upper mounting seat and the lower mounting seat, the lower end of the shaft sleeve is fixedly connected to the lower plate through the sleeve flange, and the upper end is fixedly connected to the upper plate through the shaft sleeve flange. The mounting seat and the upper mounting seat, the center of the lower mounting seat and the upper mounting seat are respectively equipped with blade joint grooves, and in order to reduce the bending moment of the blade root, the upper end surface of the lower mounting seat and the lower end surface of the upper mounting seat are usually set correspondingly The upper plate, the upper mounting seat, the lower mounting seat and the lower plate are fixed together by fixing bolts. The advantages are: due to the double-layer structure, the bending strength of the hub is greatly improved, and the overall weight is also greatly reduced. Compared with one type, the weight is reduced by 40-50%, and the processing is also simple, which greatly reduces the cost; its disadvantage is: because the total weight of the large axial flow impeller is more than 1 ton, the single blade weighs more than 11kg, and the impeller It needs to be installed at high altitude on site, so the installation is very troublesome. When installing, firstly, the upper plate needs to be pushed away with spacers, and the blade joint and mounting seat are put between the upper plate and the lower plate, and then the mounting seat is aligned with the upper plate After the positioning holes on the plate and the lower plate are aligned, they can be positioned accurately. After all the blades are positioned, they can be fixed together at last.

[0003] In addition, the blades of the above two impellers are fixedly connected on both sides of the lower blade and the upper arc blade, so that the lower blade and the upper arc A cavity is formed between the shaped blades to reduce the weight of the impeller during operation and increase the speed of the impeller. This blade is usually made by pultrusion. The pultrusion blade and the hub of the impeller are fixedly connected by steel joints. Due to the pull The wall of the extruded blade is relatively thin, and the diameter of the large axial flow impeller can reach about 10 meters. The cavity between the lower blade and the upper curved blade is relatively large. There is a support plate between the leaf plate and the upper arc leaf plate to increase the strength of the pultruded blade. The disadvantage is that during use, due to the thinner wall of the pultruded blade, the local stress at the joint between the blade and the steel is relatively large. , so that the connection between the support plate on both sides of the steel joint and the lower leaf plate and the upper arc-shaped leaf plate is prone to cracks under the action of external force, resulting in damage to the blade, and serious quality accidents will occur

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