As long as the machinery that can compress or transport gas can be called blower, so blowers, fans and even wind turbines belong to the same kind of products, centrifugal fans are also regarded as part of it. According to different requirements, centrifugal fans are designed into different structural forms, but no matter what form they are designed, they can be roughly divided into two parts: rotating parts and stationary parts.
As the rotating parts of centrifugal fan, it usually refers to the rotor, which includes spindle, impeller, pulley, coupling and other components. The static parts of centrifugal fan mainly refer to the shell, bearing box and other components, and the materials used in different parts are also required.
For stationary components such as chassis and air intake, static load is the main force to bear in general, and only a few components bear dynamic load. So when choosing materials, rigidity and strength are mainly considered, and mechanical properties are not strictly required, so Q235 materials are mostly used.
Bearing box is also a static part of centrifugal fan, but most of the force it bears is dynamic load, its size is related to the residual unbalanced weight of the rotor, and the shape of the bearing box in the centrifugal fan is complex, so cast iron is long used as its manufacturing material. When the rotor of the centrifugal fan is very heavy and the dynamic load is very large, the material of the bearing box can also be selected as advanced material. Cast steel in cast iron.
Specifically, cast iron can be used when the circumferential velocity of centrifugal fan is less than 45m/s, and cast steel can be used when the circumferential velocity is greater than 45m/s. Because the circumferential velocity of the pulley and coupling of centrifugal fan is generally not more than 40m/s, the material of cast iron grade is also the main material.