Analysis And Control Of Doformation Of Large Size Parts

Large size parts generally refer to those parts with more than one meter long in each dimension, such as low-pressure cylinder of steam turbine, wing panel of plane and so on. Large size of these parts always causes difficult processing such that gravity of parts is overweight for machine tool and gravity causes deformation in processing.This thesis analyzed elastic restitution of 600MW steam turbine unit which connects with oversize flatness error , and mainly studied that gravity, clamping and milling force contributed to elastic restitution.When analyzed deformation caused by gravity and clamping, bottom half of generator end was taken as instance. First, created its 3D model, then exerted boundary conditions and load to simulate. The results showed that when milling horizontally middle plane, stream guidance end deformed excessively in flatness, and by adding a supporting point, the deformation was controlled effectively. When milling vertically middle plane, reinforcing rib deformed excessively in perpendicularity, and by adding two support tubes on steam guidance end, the deformation was controlled effectively.When milling horizontally middle plane, by applying milling force to bearing end and steam guidance end, simulation results showed no excessive deformation arose. When milling vertically middle plane, the worst location was reinforcing rib, but simulation showed no excessive deformation arose. So the conclusion that milling force could not lead to excessive deformation was come to finally.