PROCESS FOR PRODUCING A ROTOR

• US 20100281688A1
• Filed: 05/14/2010
• Published: 11/11/2010
• Est. Priority Date: 11/19/2007
• Status: Active Grant

• Current Assignee: General Electric Technology GmbH (GE Aerospace)
• Original Assignee: Alstom Technology Ltd. (Alstom SA)
• Inventors: HARTMANN, Andreas, KELLER, Sorin
• Granted Patent: US 8,533,948 B2
• Time in Patent Office: Days
• US Class Current: 29/889.2
• CPC Class Codes: B23K 9/0026 specially adapted for particular articles or work
• CPC Class Codes: F01D 5/063 Welded rotors welding per se B23K
• CPC Class Codes: H02K 15/02 of stator or rotor bodies
• CPC Class Codes: Y10T 29/49316 Impeller making
• CPC Class Codes: Y10T 29/4932 Turbomachine making
• CPC Class Codes: Y10T 29/49321 Assembling individual fluid flow interacting members, e.g., blades, vanes, buckets, on rotary support member

Abstract

A process is provided for producing a rotor which is made by welding together disk-shaped and/or drum-shaped elements, in particular disks, wherein a device is used to join the disks together axially in sequence along a longitudinal axis and the disks are welded in a two-stage welding process. As they are joined together, the disks are stacked axially in the vertical direction. A first welding process takes place in a vertical orientation of the stacked disks, followed by a second welding process in a horizontal orientation of the stacked disks.

Claims

1. A process for producing a rotor (2) which is made by welding disks together, wherein a device is used to join the disks together axially in sequence along a longitudinal axis (A) and the disks are welded in a two-stage welding process comprising:

stacking the disks axially in a vertical direction,

carrying out a first welding process in a vertical orientation of the stacked disks, and

carrying out a second welding process in a horizontal orientation of the stacked disks.

2. The process as claimed in claim 1, wherein the first welding process is a root welding process, and the second welding process is a filler welding process.

3. The process as claimed in claim 1, wherein after the second welding process, the rotor is annealed and subjected to a material-removing turning operation and/or a quality testing operation.

4. The process as claimed in claim 1, wherein the disks are rough-turned in a horizontal position and are then stacked on top of each other in the vertical direction up to a predetermined size (L), only the first welding process being carried out while a longitudinal axis (A) of the disks which have been joined together is still in a vertical orientation, and the stacked disks, which are prewelded by the first welding process, are then tilted back into the horizontal position, and then the second welding process is carried out on the stacked disks, the longitudinal axis (A) of which is oriented horizontally.

5. The process as claimed in claim 4, wherein the second welding process is followed by tilting the prewelded, stacked disks back into the vertical position, and subjecting the disks, when their longitudinal axis (A) is in a vertical orientation, to heat treatment, in particular a stress relief annealing process, the heat treatment taking place in an annealing furnace (7) or locally.

6. The process as claimed in claim 5, wherein, after the heat treatment, the disks which have been welded to each other are tilted back into the horizontal position, and the disks, when their longitudinal axis (A) is in a horizontal orientation, are subjected to a material-removing turning operation and a quality testing operation.

7. The process as claimed in claim 1, wherein the second welding process is a twin-wire tandem narrow gap process.

8. The process as claimed in claim 1, wherein the rotor (2) is subjected to a local stress relief annealing process after it has been made by welding together stacked disks, only weld seams which are produced during the two-stage welding process being annealed, wherein use is made of inductive elements and/or resistance elements (10).

9. The process as claimed in claim 1, wherein a quality assurance operation is carried out by ultrasound on the rotor (2) in a last production step at local sites.

10. The process as claimed in claim 1, wherein at least one auxiliary wire which has been drawn from the base material of the rotor (2) is used during the first welding process and/or during the second welding process, wherein the base material is a low-alloy, heat-resistant, superclean NiCrMo grade or a high-alloy 10-13% Cr grade, a low-alloy, heat-resistant CrMo grade or a low-alloy, heat-resistant CrMoV grade.

11. The process as claimed in claim 1, wherein a substantially vertically oriented production system (5) and a substantially horizontally oriented production system (6) are suitable for receiving the overall length (L′

) of a rotor (2).

12. The process as claimed in claim 1, wherein at least two disks are joined together to form a rotor half (1a, 1b).

13. The process of claim 1, wherein three to ten disks are joined together to form a rotor half (1a, 1b).

14. The process as claimed in claim 12, wherein the at least two disks are stacked on top of each other in a vertical orientation until a predetermined length (L) of a rotor half (1a, 1b) is reached.

15. The process as claimed in claim 12, wherein the rotor (2) is made by welding together two rotor halves (1a, 1b) which are prefabricated from disks, each rotor half (1a, 1b) having a base (11) and a body (12), and the base (11) of the first rotor half (1a) is welded to the base (11) of the second rotor half (1b).

16. The process as claimed in claim 12, wherein the rotor (2) is made by welding two prefabricated rotor halves (1a, 1b) together in a two-stage welding process, the first welding process being carried out when the longitudinal axis (A) of the rotor half (1a, 1b) is in a vertical orientation, and the second welding process being carried out when the longitudinal axis (A) of the rotor half (1a, 1b) is in a horizontal orientation.

17. The process as claimed in claim 12, wherein the two rotor halves (1a, 1b) are joined together by first carrying out a root welding process, and then a filler welding process.

18. The process as claimed in claim 12, wherein the rotor (2) is prewelded in a vertical orientation in a first welding process, the prewelded rotor (2) is tilted into the horizontal position and subsequently processed in a horizontal orientation in a second welding process and the rotor (2) is then tilted back into the vertical position, the rotor (2) being subjected, in the vertical orientation, to a stress relief annealing process at welded sites.

19. The process as claimed in claim 18, wherein the rotor (2) is subjected to a material-removing turning operation in the vertical orientation.

20. The process as claimed in claim 1, wherein the rotor (2) comprises two rotor halves (1a, 1b) of equal length (L).