CENTRIFUGAL PUMP IMPELLER FORMING METHOD Russian patent published in 2006 - IPC B21K1/36 F04D29/28 

FIELD: power machine engineering, possibly production of large-size pumps with complex-shape spatial interval of inter-blade ducts, mainly main circulation pumps used in nuclear power plants in nuclear electric power stations.

SUBSTANCE: impeller is formed of two parts; each part includes two mutually joined members. One member is in the form of protrusion formed on main disc as one piece with it. Other member is formed on covering disc as one piece with it. Members of each blade are milled in order to provide possibility of their joining by butt welding and to realize quality control of their joining by irradiating with penetration irradiation. After joining before welding, portions of impeller are geometrically divided by means of surface of revolution. At movement along said surface from inlet to impeller towards its outlet the least angle between rotation axis of impeller and line normal to said surface of revolution does not increase.

EFFECT: enhanced quality of product due to increased strength of welded seam and elimination of distortion of shape of inter-blade ducts.

5 cl, 9 dwg