A flange coupling is a type of coupling with a very simple structure, mainly composed of two half couplings and connecting bolts. The main processing steps of flange couplings include boring, cutting, and repairing keyways before assembling the coupling sleeve holes, as well as processing the coupling end face and other surfaces.

   The shaft sleeve hole of the half coupling has two forms: conical hole and cylindrical hole, and conical hole has more advantages in process characteristics than cylindrical hole. The end face machining of the coupling is often carried out by fitting it onto the shaft, in order to ensure that the tenon on the coupling end face can be accurately concentric with the shaft centerline. In this machining process, special attention should be paid to ensuring that the coupling end face is perpendicular to the rotor shaft, and at the same time, attention should be paid to whether the mutual matching of the centering tenon meets the requirements. For flange couplings without centering tenons, after drilling, the two and a half couplings should be fitted together for reaming processing.

   The conical shaft sleeve hole is easy to obtain concentricity between matching components, and the contact between the coupling and the shaft matching surface can achieve a good fit. Inspection is also relatively convenient, so the use of conical holes is more common. Half couplings are generally made of forgings, with a margin of 2-3mm on each side during rough machining, and require heat treatment to eliminate residual stress before proceeding with the boring process. The boring of the coupling is usually carried out on a lathe, as high precision is required for the machining of the coupling sleeve hole. Therefore, the precision machining of the hole is usually done by grinding.

   The precision machining of the outer surface of the coupling is carried out in the same fixture for boring. The size of the processed hole and the contact between the hole and the shaft mating surface need to be inspected. For mass-produced couplings, taper sample columns can generally be used to ensure the interchangeability of the parts. Couplings produced individually can be inspected by fitting the coupling onto the shaft end. If the fit between the shaft and the hole does not meet the requirements, the hole of the coupling can be repaired and scraped.