Patent EP-2535513-A1 (EP)
Inventor: DURIEU FRANCOIS
IPC: F01D5/06
Filed: 2011-06-17
Abstract: The process comprises positioning a rotor, initiating friction of a blade (20) against an area (42) of the rotor for receiving the blade so as to reach a temperature of welding, and immobilizing the blade relative to the rotor and then forging the blade against the rotor so as to obtain a connection joint (48) between the blade and the rotor. The initiation and immobilization steps are carried out with the presence of a carrier (46) on an inner surface of the rotor opposite to the receiving area of the blade. The process comprises positioning a rotor, initiating friction of a blade (20) against an area (42) of the rotor for receiving the blade so as to reach a temperature of welding, and immobilizing the blade relative to the rotor and then forging the blade against the rotor so as to obtain a connection joint (48) between the blade and the rotor. The initiation and immobilization steps are carried out with the presence of a carrier (46) on an inner surface of the rotor opposite to the receiving area of the blade. A length of a contact surface of the carrier with the inner surface of the rotor along a rotational axis of the rotor is 50% of the length of the receiving region of the blade so as to generate, after cooling and release of pressure, a concentration of compressive stress in the center of the thickness of the connecting joint with an axial end of the joint. The rotor comprises a floor wall that is symmetrical in revolution about the rotational axis of the rotor, and a hollow internal volume. The wall has, at the receiving area of the blade, a longitudinal section with a U-shaped profile with its opening directed towards the rotational axis of the drum and stiffening portions (43, 45), and forms a web corresponding to the rotor. The contact surface of the carrier with the inner surface in a cavity has a length, along the rotational axis of the rotor, that is less than the length of a bottom of the cavity. The profile of the longitudinal section comprises a central portion (44) relative to the web. The stiffening portions connect the central portion to the web. The carrier is disposed in the cavity and on the inner surface of the central portion. The stiffening portions are perpendicular to the rotational axis of the rotor or at an angle of 40[deg] with a perpendicular direction to the axis, and are laterally disposed on a side of the central portion projecting from one of the stiffening portions so as to form a section in a form of pi . An outer surface of the central portion defines a fluid stream, and has cylindrical, conical or convex shape along the length of the surface. The receiving area of the blade is formed by a projection of the outer surface of the rotor. The projection forms a lower portion of the blade when the blade is welded to the rotor, where the lower portion corresponds to 20% of the height of the blade. The carrier is arranged so that its contact surface with the inner surface of the rotor is centered with the receiving area of the blade in the direction of the rotational axis of the rotor. An independent claim is included for a rotor of axial turbomachine.