Abstract: Semi-opened impeller belong to the complicated curved surface parts,is widely used in centrifugal pump.It carries out the structure parameter calculation and drawing of a semi-opened impeller,then it creates the accurate 3D model by UG software,and analyzes the numerical control machining process of the impeller.Then it carries on programming and simulation of numerical control (NC) machining tool path for the impeller in UG software.Finally,the generated numerical control program is passed to the machining center for actual processing.In this way,a size accuracy and good surface quality semi-opened impeller is machined.

Key words: semi-opened impeller, UG software, CAD/CAM, numerical control machining