METHOD FOR MANUFACTURING A HOUSING OF A TURBOMACHINE AND TURBOMACHINE HOUSING

Abstract

The invention relates to a method for manufacturing a housing of a turbomachine, in particular a gas turbine. The method comprises at least the steps: providing a housing blank (10), manufacturing a housing element (14), producing an assembly opening (12) corresponding to the housing element (14) in the housing blank (10), arranging the housing element (14) in the assembly opening (12), and joining the housing element (14) to the housing blank (10) by means of a welding method. In addition, the invention relates to a turbomachine housing.

Claims

1. A method for manufacturing a housing of a turbomachine, comprising the steps of: providing a housing blank (10); manufacturing a housing element (14); producing an assembly opening (12) corresponding to the housing element (14) in the housing blank (10); arranging the housing element (14) in the assembly opening (12); and joining the housing element (14) to the housing blank (10) by welding.

2. The method according to claim 1, wherein a housing blank (10) with an at least substantially rotationally symmetrical, particularly cylindrical or conical, geometry is provided.

3. The method according to claim 1, wherein the housing element (14) is manufactured by at least one method selected from the group consisting of: machining, electrochemical machining (ECM), additive manufacturing methods, laser beam melting and/or electron beam melting.

4. The method according to claim 1, wherein the housing element (14) is manufactured on and/or with a platform (16) to be arranged in the assembly opening (12), wherein the platform (16) has a wall thickness (d) substantially corresponding to the wall thickness (d) of the housing blank (10).

5. The method according to claim 1, wherein an assembly opening (12) with an at least substantially circular or oval or polygonal geometry is produced in the housing blank (10).

6. The method according to claim 1, wherein the housing element (14) is aligned by arranging it by at least one centering element relative to the assembly opening (12).

7. The method according to claim 1, wherein the assembly opening (12) is produced by at least one separating method, in particular from the group: eroding, milling, and laser beam cutting.

8. The method according to claim 1, wherein the housing blank (10) is heated prior to arranging the housing element (14) in the assembly opening (12), and the housing element (14) is subsequently shrunk fit into the assembly opening (12).

9. The method according to claim 1, wherein the housing element (14) is attached to the housing blank (10) by at least one welding method selected from the group consisting of: electron beam welding and laser beam welding.

10. The method according to claim 1, wherein the housing element (14) includes at least one structural element selected from the group consisting of: flange, local thickened area, shoulder, through-guide, and/or strut.

11. The method according to claim 1, wherein the housing blank (10) is thermally expanded, after which at least one rail (22) is arranged and shrunk fit in the housing blank (10), and/or in that a flange (26) is thermally expanded, after which the flange (26) is arranged on the housing blank (10) and is shrunk fit onto the housing blank (10).

12. The method according to claim 11, wherein at least one stop piece (24) is manufactured on the housing blank (10), and the rail (22) and/or the flange (26) is/are aligned relative to the housing blank (10) by this stop piece.

13. The method according to claim 12, wherein the stop piece (24) is manufactured by milling, and/or is joined to the housing blank (10) by welding and/or adhesive bonding.

14. The method according to claim 11, wherein the rail (22) and/or the flange (26) are welded to the housing blank (10) by a peripheral weld (20) and/or a fillet weld and/or an I-butt and/or and I-seam.

15. The method according to claim 1, wherein the turbomachine is a gas turbine.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0021] Further features of the invention result from the claims and the examples of embodiment. The features and combinations of features named above in the description, as well as the features and combinations of features named in the examples of embodiment below and/or shown alone can be used not only in the combination indicated in each case, but also in other combinations or uniquely, without departing from the scope of the invention. Thus, embodiments of the invention that are not explicitly shown and explained in the embodiment examples, but proceed from the explained embodiments and can be produced by separate combination of features, are also to be viewed as comprised and disclosed. Embodiments and combination of features that thus do not have all features of an originally formulated independent claim are also to be viewed as disclosed. Herein:

[0022] FIG. 1 shows a schematic perspective view of a housing blank with an assembly opening;

[0023] FIG. 2 shows a schematic perspective view of a housing element;

[0024] FIG. 3 shows a schematic perspective view of the housing blank, in which the housing element is arranged in the assembly opening and is welded to the housing blank;

[0025] FIG. 4 shows a schematic lateral sectional view of a region of the housing blank, in which a rail is welded to the housing blank;

[0026] FIG. 5 shows a schematic lateral sectional view of a region of the housing blank, in which a rail is welded to the housing blank in an alternative manner;

[0027] FIG. 6 shows a schematic lateral sectional view of a region of the housing blank, on which a flange is welded to the housing blank; and

[0028] FIG. 7 shows a schematic lateral sectional view of a region of the housing blank, on which an alternative flange is arranged and welded to the housing blank.

DESCRIPTION OF THE INVENTION

[0029] FIG. 1 shows a schematic perspective view of a housing blank 10 of a gas turbine.

[0030] It is recognized that the housing blank 10 is formed at least substantially rotationally symmetrical or cylindrical. An assembly opening 12 that corresponds to a housing element 14, which is shown schematically in FIG. 2, is produced in the housing blank 10. For this purpose, the housing element 14 comprises a platform 16, the dimensions of which (height H, width B, thickness d) correspond to those of the assembly opening 12. In particular, the thickness d of the platform 16 corresponds to the wall thickness d of the housing blank 10. The assembly opening 12 has a geometry that is as simple as possible (optionally with rounded edges); for example, it is circular or rectangular. The assembly opening 12 can be manufactured with the aid of a cutting method; thus, for example, by eroding, milling, or laser beam cutting.

[0031] In addition, the housing element 14 comprises local design features or structural elements 18, which are formed on the platform 16. Structural elements 18 can comprise, for example, flanges, local thickened areas, shoulders, through-guides, and/or struts, in order to provide the housing blank 10 with specific properties, connection points, or the like. The housing element 14 thus can be manufactured separately, independently from the fabrication of the housing blank 10, for example, by machining, ECM, or by additive manufacture. The platform 16 can be provided as the base for building up the structural element 18 or it can be manufactured together with the structural element 18, depending on the manufacturing method. In the case of an additive manufacture, laser beam melting or electron beam melting is preferably used, in order realize a so-called near net shape geometry, i.e., a geometry that is close to the final contours and requires no additional processing.

[0032] FIG. 3 shows a schematic perspective view of the housing blank 10, in which the housing element 14 is arranged in the assembly opening 12 and is welded to the housing blank 10 with the formation of a peripheral weld 20. This is preferably conducted by electron beam welding or laser beam welding. The advantages of this manufacturing method, in addition to minimizing the costs of the blank, in particular include a reduction in fabricating time, since the design features 18 can be manufactured on the housing blank 10 independently from the fabrication sequence. Also, when joining the housing element 14 there is a much smaller introduction of heat into the housing blank 10, so that a delay is advantageously avoided for the housing blank 10. In addition, it can be provided that the housing element 14 and the housing blank 10 have centering elements corresponding to one another (e.g., a centering lip), in order to ensure a correct three-dimensional arrangement relative to one another (“failproof design”). Likewise, it can be provided that the housing element 14 is shrunk fit into the assembly opening 12. For this purpose, the housing blank 10 is first heated to around a specific temperature ΔT before the housing element 14 is arranged in the assembly opening 12. Upon cooling, a force-fit connection results between the housing blank 10 and the housing element 14.

[0033] FIG. 4 shows a schematic lateral sectional view of a region of the housing blank 10, in which an annular rail 22, i.e., an internal flange, is welded peripherally to the housing blank 10, with the formation of a weld 20 executed as an I-seam. For welding the rail 22 or a flange 26, it is in fact generally possible, but usually not necessary, to use welding fillers. Prior to welding, the rail 22 is aligned by means of a stop piece 24 provided with a centering lip 28, opposite the housing blank 10. The stop piece 24 can be manufactured, for example, peripherally by a milling technique, wherein this requires, if need be, a small machining allowance of the housing contour. It is likewise possible to join the stop piece 24 to the housing blank 10 by means of a joining technique. Spot welding, adhesive bonding, etc. are conceivable as joining methods.

[0034] FIG. 5 shows a schematic lateral sectional view of a region of the housing blank 10, in which an annular rail 22 is welded peripherally to the housing blank 10, with the formation of a fillet weld 20. Prior to welding, the rail is aligned again opposite the housing blank 10 by means of a stop piece 24. The stop piece 24 can also be manufactured peripherally by a milling technique, whereby this may require a small machining allowance of a few tenths of a millimeter for the housing contour. Likewise, it is also possible in this case, of course, to join local seating elements to the housing blank 10 by a joining technique. Spot welding, adhesive bonding, etc. are conceivable as joining methods. Additionally, it can be provided to shrink fit the rail 22 in the housing blank 10 prior to welding. For this purpose, the housing blank 10 is heated first in an oven to a temperature ΔT according to the formula (I)

ΔT=ΔD/(α*D)   (I)

[0035] in which

[0036] ΔT: temperature increase

[0037] α: thermal expansion coefficient

[0038] D: diameter of the housing blank 10

[0039] ΔD: difference in the diameters of housing blank 10 and rail 22.

[0040] If the housing blank 10 and the rail 22, for example, are composed of the material IN718 with α≈1.2*10.sup.−5 K.sup.−1, for D=1 m and ΔD=5/10 mm, a temperature increase ΔT≈40 K is necessary. It is generally preferred if the rail 22 is composed of a highly heat-resistant material, since high temperatures occur in this region during the operation of the finished turbomachine. The use of a highly heat-resistant material thus particularly prevents the occurrence of cracks and other wear phenomena (fretting). In addition, it can be provided that the rail 22 and the housing blank 10 have mutually corresponding centering elements (e.g., a centering lip 28) in order to ensure a correct three-dimensional arrangement relative to one another (“failproof design”). Several rails 22 can be manufactured by repeatedly applying the above-described procedure in one direction (i.e., from “bottom to top” or from “top to bottom”).

[0041] FIG. 6 shows a schematic lateral sectional view of a region of the housing blank 10, in which a flange 26 is welded to the housing blank 10. For this purpose, first a stop piece 24 is manufactured on the upper edge of the housing blank 10 by milling a peripheral groove. Subsequently, the annular flange 26 is positioned on the housing blank 10 and welded to the latter. In the present example of embodiment, this is carried out by means of another peripheral weld 20 formed as an I-butt. It can be basically provided that the flange 26 and the housing blank 10 have mutually corresponding centering elements (e.g., “centering lip”) in order to ensure a correct three-dimensional arrangement relative to one another (“failproof design”). Additionally, it can be provided that the flange 26 is heated prior to arranging on the housing blank 10 and is shrunk fit on the housing blank 10. Formula (I) above can be drawn on to determine the temperature increase ΔT necessary for this.

[0042] FIG. 7 shows a schematic lateral sectional view of a region of the housing blank 10, on which an alternative flange 26 is arranged and welded to the housing blank 10. Unlike the previous exemplary embodiment, the housing blank 10 does not comprise a stop piece 24. The annular flange 26 is thus arranged only on the housing blank 10 and welded to the latter by means of a fillet weld 20. Optionally, it can be provided that the flange 26 and the housing blank 10 have mutually corresponding centering elements (e.g., “centering lip”) in order to ensure a correct three-dimensional arrangement relative to one another (“failproof design”).