Unknown

Abstract

The invention relates to a guide vane for a gas turbine, comprising an airfoil, a platform arranged at a radial end of the airfoil, an upstream flange extending radially from the platform, and a downstream flange extending radially from the platform, wherein the flanges, together with a section of the platform lying between the flanges, bound a groove extending in the circumferential direction of the gas turbine for the arrangement of a damping element. A surface of the section of the platform bounding the groove is arched radially at least in regions thereof in the direction of an opening of the groove. The invention further relates to a guide vane cluster, a housing for a gas turbine, as well as to a gas turbine.

Claims

1. A guide vane for a gas turbine, comprising an airfoil: a platform arranged at a radial end of the airfoil, an upstream flange extending radially from the platform, and a downstream flange extending radially from the platform, wherein the flanges, together with a section of the platform lying between the flanges, bound a groove extending in the circumferential direction of the gas turbine for the arrangement of a damping element, wherein a surface of the section of the platform bounding the groove is arched radially at least in regions thereof in the direction of an opening of the groove.

2. The guide vane according to claim 1, wherein a surface of the platform facing away from the groove is arched radially at least in regions thereof in the direction of the opening of the groove and/or in that, in cross section, the section of the platform has an at least essentially uniform wall thickness.

3. The guide vane according to claim 1, wherein the airfoil has an exposed vane tip with respect to the platform.

4. The guide vane according to claim 1, wherein the upstream flange has a downstream overhang in the groove, and/or in that the downstream flange comprises an upstream overhang in the groove, and/or in that the upstream flange has an upstream overhang, which, together with the platform, forms a further groove extending in the circumferential direction of the gas turbine, and/or the downstream flange has a downstream overhang, which, together with the platform, forms a further groove extending in the circumferential direction of the gas turbine.

5. A guide vane cluster for a gas turbine, in which at least two guide vanes according to claim 1, are connected to one another by way of at least one common platform for the radial bounding of a flow channel of the gas turbine.

6. A housing for a gas turbine, with a flow channel, comprising: a plurality of guide vanes each including: a platform arranged at a radial end of the airfoil, an upstream flange extending radially from the platform, and a downstream flange extending radially from the platform, wherein the flanges, together with a section of the platform lying between the flange, bound a groove extending in the circumferential direction of the gas turbine for the arrangement of a damping element, wherein a surface of the section of the platform bounding the groove is arched radially at least in regions thereof in the direction of an opening of the groove; and/or a plurality of guide vane clusters each including: at least two of the guide vanes connected to one another by way of at least one common platform for the radial bounding of a flow channel of the gas turbine; are arranged in a cascade manner, wherein the grooves of the guide vanes and/or the guide vane clusters extending in the circumferential direction of the gas turbine are aligned flush with one another, and wherein at least one damping element is arranged in at least one of the grooves.

7. The housing according to claim 6, wherein the at least one damping element has a recess in the region of the section of the associated platform arched radially in the direction of an opening of the groove, and/or, in cross section, the damping element is U-shaped or O-shaped or clamp-shaped in design, and/or the damping element is configured and arranged to be linear in the circumferential direction.

8. The housing according to claim 6, wherein, in cross section, the damping element has at least three contact points in the groove, and/or the damping element has at least two contact points with the housing.

9. The housing according to claim 6, wherein the damping element is arranged in a bridging manner between at least two mutually adjacent guide vanes and/or guide vane clusters.

10. An aircraft engine with at least one guide vane according to claim 1.

11. An aircraft engine with at least one guide vane cluster according to claim 5.

12. An aircraft engine with at least a housing according to claim 6.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0017] Further features of the invention ensue from the claims and the exemplary embodiments. The features and combinations of features mentioned in the above description as well as the combinations of features mentioned in the following examples can be used not only in the respectively specified combinations but also in other combinations or alone, without leaving the scope of the invention. Therefore, embodiments of the invention that are not explicitly shown and explained in the examples are also be regarded as included and disclosed. Embodiments and combinations of features that do not have all features of an independent claim as originally formulated are also to be regarded as disclosed. Shown are:

[0018] FIG. 1 a perspective view of two guide vane clusters according to the invention;

[0019] FIG. 2 a schematic sectional view through a platform of a guide vane cluster arranged on a housing of a gas turbine;

[0020] FIG. 3 a schematic and sectional perspective view of the guide vane cluster arranged on the housing, with an alternative damping element being arranged in a groove; and

[0021] FIG. 4 a schematic and sectional perspective plane view of a platform of a guide vane cluster, with a further alternative damping element being arranged in the groove.

DESCRIPTION OF THE INVENTION

[0022] FIG. 1 shows a perspective view of two guide vane clusters 10 according to the invention, which are arranged in a way that is known as such with further guide vane clusters 10 in a cascading manner as a stator group in a housing 12 (see FIG. 2) of a gas turbine (not shown), in particular a gas turbine of an aircraft engine. Each guide vane cluster 10 has a plurality of airfoils 14, which are connected to one another by way of a common, radial outer platform 16. The platform 16 forms a shroud for the bounding of a flow channel S of the associated gas turbine. In the exemplary embodiment shown, the guide vane cluster 10 is designed as a so-called cantilevered construction, so that the vane tips 18 of the airfoils 14 are exposed. FIG. 1 will be explained below in conjunction with FIG. 2, which shows a schematic sectional view through the platform 16 of a guide vane cluster 10 arranged on the housing 12 of the gas turbine. It can be seen that the platform 16 has an upstream flange 20 extending radially from the platform 16 and a downstream flange 22 extending radially from the platform 16. The flanges 20, 22, together with a section 24 of the platform lying between the flanges 20, 22, form a groove 26 extending in the circumferential direction U of the gas turbine or of the housing. As shown in FIG. 2, a clamp-shaped damping element 28 is arranged in the groove 26 for vibrational damping. As can be seen in FIG. 2, in particular, a surface of the section 24 of the platform 16 bounding the groove 26, is arched radially at least in regions thereof in the direction of a radial upper opening of the groove 26. In other words, the surface of the platform 16 forming the floor or a wall region of the groove 26 is not planar or formed from circular cylindrical segments in the circumferential direction, but rather, in cross section, has a convex arch in the axial direction, which may also be referred to as a relative thickening, a rib, or a contact rib. Such an uneven form of the floor of the groove 26 makes possible an improved frictional contact and accordingly an improved force transmission for the damping element 28 arranged in the groove 26, which, in accordance therewith, can form a more uniform and operationally secure contact to a guide vane or a guide vane cluster 10 and hence realize an improved vibrational damping. In FIG. 1, the rib-shaped thickening or deformation of the platform 16 can be seen and, in the case of a fully mounted guide vane cascade, is formed around the circumferential side. As can be seen in FIG. 2, it is possible in many embodiments for a surface of the section 24 of the platform 16 facing away from the groove 26 also to be arched radially at least in regions thereof in the direction of the opening of the groove 26, as a result of which, in cross section, the section 24 of the platform 16 has an at least essentially uniform or constant wall thickness. Beyond this, the platform 16 accordingly has an aerodynamically favorable wall contour for the passing flow of working medium during operation of the gas turbine. Preferably, the guide vane or the guide vane cluster 10 is additively manufactured in order that the mentioned geometric features can be realized simply and reliably. The present u-shaped damping element 28 has at least three contact points or areas and lies upstream against the flange 20, in its middle region against the rib-shaped section 24, and downstream against the flange 22. As can be seen further in FIG. 2, the downstream flange 22 has wall inclined downstream, against which a downstream arm of the damping element 28 rests, as well as, at its radial outer end region, an upstream overhang 30, which projects into the groove 26 and bounds the opening of the groove 26, as a result of which a kind of pocket or securing against falling out as well as, if need be, an additional contact point for the damping element 28 are realized. Furthermore, the downstream flange 22 has a downstream overhang 32, which, together with the platform 16, forms a further groove 34, which extends likewise around the circumferential side and is suitable for mounting fastening hooks or the like for fixing the guide vane cluster 10 to the housing 12, to a sealing element, or to other structural elements. Accordingly, in cross section, the flange 22 has an approximatively T-shaped form. Regardless of the flange 22, it is fundamentally possible for the flange 20 to have a T-shaped form as well.

[0023] The upstream flange 20, on its part, has a wall that is inclined upstream, against which an upstream arm of the damping element 28 rests. Furthermore, the flange 20 comprises an upstream overhang 36, which likewise serves for the fastening of the guide vane cluster 10. On their part, the overhangs 30, 32, 36 function, in addition, as additional damping elements.

[0024] FIG. 3 shows a schematic and sectional perspective view of the guide vane cluster 10 arranged on the housing 12, with an alternative damping element 28 being arranged in the groove 26. The general construction of the guide vane cluster 10 corresponds to the above exemplary embodiment. In contrast to the above u-shaped damping element 28 in FIG. 2, the damping element 28 in the present case is clamp-shaped in form or is bent back upon itself in some regions. In this way, the damping element 28 has, in addition to the previously mentioned three contact points or areas IIIa in the groove, a contact site IIIb with itself as well as, optionally, a contact site IIIc with the housing 12. The vibrational damping can therefore be realized not only by friction with the guide vane cluster 10, but also by friction in itself as well as, if need be, by friction with the housing 12.

[0025] FIG. 4 shows a schematic and sectional perspective plane view of a platform 16 of a guide vane cluster 10, with a further alternative damping element 28 being arranged in the groove 26. In contrast to the previous exemplary embodiments, the platform 16 in the section 24 is not deformed on its side facing the flow channel S, but rather has a flat contour. Furthermore, the damping element 28 has a recess 38 in the contact region with the section 24 of the platform 16 for adaptation of its damping properties. Furthermore, it can be seen that an end region E of the damping element 28 extends obliquely with respect to the edge of the platform 16 and does not end flush with the platform 16. In this way, it is possible to arrange the damping elements 28 of adjacent guide vane clusters 10 in an overlapping or segment-overlapping manner, as a result of which it is possible advantageously to dispense with additional sealing plates or the like. In the case of short guide vane clusters 10 or individual vanes, it is possible to design the damping element 28 as a straight element, thereby simplifying its fabrication.