Method for attaching a spring washer to a combustion chamber housing

Abstract

The invention relates to a method for fastening a spring washer (05) to a combustion chamber housing (02). The combustion chamber housing (02) has a cylindrical receiving section (03) at least at the downstream end. The spring washer (05) comprises a cylindrical fastening section (06) and a plurality of spring tabs (07) distributed around the circumference. First, a brazing material is applied to the inside of the fastening section (06). The spring ring (05) is then joined to the combustion chamber housing (02) so that the fastening section (06) is located on the receiving section (03). Heating the fastening section (06) and / or the receiving section (03) creates a connection between the fastening section (06) and the receiving section (03). The spring tabs (07) are cooled at the same time.

Description

TECHNICAL FIELD

[0001] The invention relates to a method for fastening a spring ring to a combustion chamber housing. BACKGROUND

[0002] In gas turbines, it is common practice to install a transition duct to the expansion turbine adjacent to a combustion chamber casing. The combustion chamber casing is inserted into the transition duct in sections. Elastically deformable spring tabs are often used in the connection between the combustion chamber casing and the transition duct, which are attached to the combustion chamber casing at distributed locations around the circumference.

[0003] As a rule, the spring tabs are attached individually or in groups to the combustion chamber housing by welding.

[0004] The spring tabs are subject to high dynamic and thermal stress, so they usually need to be repaired or replaced over the course of the gas turbine's service life. For this purpose, they are mechanically removed and new parts are then welded on.

[0005] The disadvantage is, on the one hand, the effort required to weld the spring tabs on. On the other hand, the welding process causes deformation of the combustion chamber housing, which in turn negatively impacts its service life. SUMMARY OF THE INVENTION

[0006] The task is therefore to provide an improved repair process.

[0007] The object is achieved by a method according to the invention according to the teaching of claim 1. Advantageous embodiments are the subject of the dependent claims.

[0008] The method serves to attach a spring washer to a combustion chamber housing. The combustion chamber housing has a cylindrical receiving section at least at the downstream end. The spring washer (05) comprises a cylindrical fastening section and a plurality of spring tabs distributed around the circumference.

[0009] First, a brazing material is applied to the inside of the mounting section. The spring washer is then joined to the combustion chamber housing so that the mounting section is positioned on the receiving section. Heating the mounting section and / or the receiving section creates a connection between the mounting section and the receiving section. The spring tabs are cooled at the same time. DESCRIPTION OF THE INVENTION

[0010] The method is used to attach a spring washer to a combustion chamber housing. The shape of the combustion chamber housing is initially irrelevant. At a minimum, it is required that it has a cylindrical receiving section at the downstream end. The spring washer comprises, as essential elements, a cylindrical fastening section and a plurality of spring tabs.

[0011] Preferably, the inner diameter of the fastening section substantially corresponds to the outer diameter of the receiving section. Taking into account the intended assembly and fastening method, a slight difference between the inner diameter of the fastening section and the outer diameter of the receiving section may be advantageous.

[0012] The design of the spring tabs is initially irrelevant for the process. Regarding their function as a subsequent connection between the combustion chamber housing and a transition section, they preferably extend in the direction of flow with a distance from the center axis of the spring ring increasing upstream. To ensure the elastic properties of the spring tabs, they are separated from each other by a gap and connected only on the side of the fastening section.

[0013] For the fastening according to the invention, a solder material must be applied to the inside of the fastening section. How this is applied is initially irrelevant. At the very least, it should be evenly distributed around the circumference.

[0014] It is particularly advantageous to apply the solder material using a build-up welding process, so that the solder material appears in the form of a coating.

[0015] In the next step, the spring ring is mounted on the combustion chamber housing so that the fastening section surrounds the receiving section.

[0016] It can be advantageous to first heat the spring washer, or at least the fastening section, before joining. Alternatively or additionally, the combustion chamber housing or at least the receiving section can be cooled. Care must be taken to ensure that the temperature of the spring washer is not set too high, so that, on the one hand, the solder material remains in the applied area and, on the other hand, the spring tabs are not thermally damaged. At the very least, the thermal difference leads to different expansions of the components, thus simplifying the joining process.

[0017] After the spring ring has been arranged at the intended location, the fastening section and / or the receiving section are heated so that the solder material is at least partially melted.

[0018] After the assembly has cooled down, the spring ring is firmly connected to the combustion chamber housing.

[0019] The advantageous method for attaching the spring washer prevents, in particular, thermal deformation of the combustion chamber housing and the spring washer. This leads to a better fit of the assembly during later use in the transition channel and thus to a longer service life.

[0020] It is advantageous that the heating takes place inductively.

[0021] Furthermore, it is advantageous to provide active cooling of the spring tabs simultaneously with the heating, so that they are not thermally damaged and do not lose some of their elasticity. Cooling air is supplied to the spring tabs in a both simple and advantageous manner.

[0022] For this purpose, a joining tool is particularly advantageously used, which is positioned over the spring ring and contains at least one induction coil. Care should be taken to ensure that the joining tool allows the cooling air to be guided along the spring tabs while shielding it from the fastening section. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 outlines an example combustion chamber housing 02. Fig. 2 schematically sketches a spring ring 05 during the application of the solder material. Fig. 3 schematically outlines the process of attaching the spring ring 05 to the combustion chamber housing 01. Fig. 4 outlines a combustion chamber arrangement 01 with the combustion chamber housing 02 and the spring ring 05. DESCRIPTION OF THE EMBODIMENTS

[0023] In the Fig. 1 shows an exemplary combustion chamber housing 02. This housing 02 has a cylindrical receiving section 03 at the downstream end.

[0024] In the Fig. 2 shows an example of a spring ring 05 which has a cylindrical fastening section 06 and a plurality of spring tabs 07 arranged distributed around the circumference.

[0025] Furthermore, the application of the solder material to the inside of the fastening section 06 is schematically outlined.

[0026] In the Fig. 3 shows the combustion chamber housing 02 with the spring ring 05 mounted thereon, wherein the fastening section 06 of the spring ring 05 is surrounded by a joining tool 11. It is provided that an induction coil for heating the fastening section 06 is arranged in the joining tool 11.

[0027] Furthermore, Fig. 3 shows a cooling air supply 12, which is intended for cooling the spring tabs 07. The cooling air should preferably be shielded from the fastening section 06 and diverted from the joining tool 11.

[0028] In the Fig. 4 shows the finished combustion chamber arrangement 01 with the combustion chamber housing 02 and the spring ring 05 attached to it.

Claims

[1] Method for fastening a spring ring (05) to a combustion chamber housing (02), wherein the combustion chamber housing (02) has a cylindrical receiving section (03) at least at the downstream end and the spring ring (05) has a cylindrical fastening section (06) and a plurality of spring tabs (07) distributed around the circumference, comprising the steps - application of a solder material on the inside of the fastening section (06), - joining the spring ring (05) to the combustion chamber housing (02) with the positioning of the fastening section (06) on the receiving section (03), - Heating of the fastening section (06) and / or the receiving section (03) while simultaneously cooling the spring tabs (07). [2] The method according to claim 1, wherein the solder material is applied by means of build-up welding. [3] Method according to claim 1 or 2, wherein at least the receiving portion (03) of the combustion chamber housing (02) and / or the spring ring (05) and / or the solder material is based on a nickel-based alloy. [4] Method according to one of claims 1 to 3, wherein the heating is carried out inductively. [5] Method according to one of claims 1 to 4, wherein the cooling is carried out by active air cooling. [6] Method according to one of claims 1 to 5, wherein a joining tool (11) is arranged on the spring ring (05) for heating and cooling, wherein the joining tool (11) comprises an induction coil and cooling air duct. [7] Method according to one of claims 1 to 6, wherein the fastening section (06) is heated and / or the receiving section (03) is cooled before the spring ring (05) is joined to the combustion chamber housing (02).

Images