Large industrial fan blades three kinds of connection mode respective characteristics

Large industrial fan blade three kinds of connection mode respective characteristics
 
Large industrial fan because the fan blade length is longer, the blade is heavier, so that the root of the blade connection to withstand a greater load, the blade root structure size is large, and the root of the blade is the weak link of the overall structure, the connection of the failure mode is more, and the strength of the prediction is more difficult, so the root of the blade connection is critical. At present, there are three main ways to connect the root of large industrial fan blades on the market, one is T-bolt connection, which is perpendicular to the end face of the root along the circumferential direction of the uniformly punched circle of bolt holes, and in the corresponding orientation of the bolts, along the radial direction perpendicular to the bolt holes and the bolt holes in the direction of the hole of the round nut. One end of the double-ended screw is connected with the round nut, and the other end is connected with the bearing mounted on the hub, and the double-ended bolt and the nut become a T-type structure. As the bolt hole and the round nut hole are punched after the blade is molded, the punching accuracy is also guaranteed by the equipment, there is no need to consider the root connection problem in the production of fan blades, and will not be affected by the curing shrinkage and other problems during the blade manufacturing process and the root connection accuracy, and thus the manufacturing of blades is relatively simple, especially suitable for the production of large-scale assembly line industrial fan blades. The other is the pre-embedded bolt connection, which consists of pre-embedded bolt sleeve and double-headed screw. Pre-embedded bolt sleeve outer surface has a wavy or toothed ring raised, and the surface of the sandblasting treatment to improve the surface cleanliness and roughness, in the use of continuous fiberglass bundles winding to fill the grooves before use. Because the root of the blade is two half-cylindrical mold bonding, mold precision also directly affects the bolt connection precision. Pre-embedded bolt connection of the blade root end face is generally no longer do trimming, flatness is dependent on the molding and molding end face of the mold to ensure the flatness. Therefore, the manufacturing of pre-embedded bolt connection on the mold root stiffness, pre-embedded bolt positioning tooling manufacturing accuracy and structural reasonableness, as well as blade mold mold molding accuracy, manufacturing process puts forward higher requirements, but also increase the probability of quality problems of the blade. There is also a kind of implanted bolt connection, is in the large industrial fan blade root end face according to the requirements of the axial connection bolt holes, will be implanted in the steel connecting anchor bolt holes axial connection bolt holes, and with epoxy adhesive bonding. However, this method makes it impossible to replace the steel connecting anchors, and an improved method is to implant connecting parts similar to pre-embedded bolt sets in the axial connecting bolt holes, and then connect with the host computer with a double-ended screw.