1. Generally, ductile iron is preferred as the hub material of wind turbines. Physical and chemical inspection must be carried out after the wheel hub is cast, and the casting blank must not have casting defects such as cracks, shrinkage cavities, shrinkage porosity and sand holes.

2. Measure the actual distance between the longitudinal center line of the hub and the upper surface of the spindle from the scribing platform, and calculate the machining allowance as the machining allowance of the upper and lower spindle surfaces; Using the excircle or blank hole of the upper and lower spindle blank as a rough reference, find out the center line of the spindle hole, and then draw the distance line between the center line and the three blade mounting surfaces based on the center line, and the distance between the center line and the blade mounting blank surface is the machining allowance of the blade mounting surface. Check whether the machining allowance on the installation surface of the three blades is consistent. If the machining allowance deviation is large, adjust them one by one until the machining allowance of the three blade mounting surfaces is consistent.

3, vertical lathe machining alignment benchmark generally use line drawing flat line.

4. After the vertical lathe is qualified, the machining of the three blade mounting surfaces will be completed by the CNC boring machine, in which the deviation of marking will be checked by the CNC boring machine programming, and the accurate machining dimensions of the three blade mounting surfaces will be guaranteed by the fixture and CNC programming. According to the datum on the positioning seat, calculate the Y-direction center lines of the three blade mounting surfaces, and then divide them into equal parts with 120 degrees, which runs through the horizontal direction of the blade mounting surfaces, so as to determine the equal parts of the three blade mounting surfaces.

4. After the machining of the hub spindle hole and the three blade mounting surfaces is completed, the machining of the seat surface screw holes in other positions is generally completed by drilling fixtures, so that the positioning is accurate and the position and size are completely guaranteed. After the mechanical processing is completed, all exposed burrs and acute angles should be polished smooth and flat.