ROTATING BLADE FOR A TURBOMACHINE

Abstract

The present invention relates to a rotating blade for a turbomachine, having a blade element and a shroud, wherein the shroud is profiled at a peripheral side, i.e., when observed in a tangential section, has a contact flank that is oriented axially, at least proportionally, and has a free flank that is also oriented axially, at least proportionally, and is in fact opposite the contact flank, wherein, when observed in the tangential section, an intermediate segment between the contact flank and the free flank has a first curvature in a first transition segment to the contact flank and has a second curvature in a second transition segment to the free flank, wherein the first curvature is greater than the second curvature.

Claims

1. A rotating blade for a turbomachine, comprising a blade element and a shroud, wherein the shroud is profiled at a peripheral side when observed in a tangential section, has a contact flank that is oriented axially, at least proportionally, and has a free flank that is also oriented axially, at least proportionally, and is opposite the contact flank, wherein, when observed in the tangential section, an intermediate segment between the contact flank and the free flank, in a first transition segment to the contact flank has a first curvature and in a second transition segment to the free flank has a second curvature, wherein the first curvature is greater than the second curvature.

2. The rotating blade according to claim 1, in which the intermediate segment between the first and the second transition segments has a central segment, which runs linearly when observed in the tangential section.

3. The rotating blade according to claim 1, wherein, in the intermediate segment, the first and the second transition segments transition directly into one another.

4. The rotating blade according to claim 1, wherein the intermediate segment, when observed in the tangential section, has a constant first radius of curvature R.sub.1 over the first transition segment.

5. The rotating blade according to claim 1, wherein the intermediate segment, when observed in the tangential section, has a constant second radius of curvature R.sub.2 over the second transition segment.

6. The rotating blade according to claim 4, wherein the intermediate segment, when observed in the tangential section, apart from a linear extension that is in sections, is included exclusively with the first and the second radii of curvature R.sub.1, R.sub.2.

7. The rotating blade according to claim 1, wherein, when observed in a tangential section, from the linear contact flank to the particularly linear free flank, every curvature of the peripheral side has the same sign and/or every transition from a curved to a linear segment is tangential.

8. The rotating blade according to claim 1, wherein the first transition segment, when observed in the tangential section, transitions tangentially into the particularly linear contact flank.

9. The rotating blade according to claim 1, wherein the second transition segment, when observed in the tangential section, transitions tangentially into the particularly linear free flank.

10. The rotating blade according to claim 1, wherein, when observed in the tangential section, an angle bisecting line that lies in the middle between the contact flank and the free flank and bisects the intermediate segment in a groove base, lies diagonally to a tangent placed in the groove base of the intermediate segment.

11. The rotating blade according to claim 1, wherein the intermediate segment, when observed in the tangential section, apart from a linear extension optionally in sections, is curved exclusively concavely.

12. A rotating blade ring having a rotating blade according to claim 1.

13. A turbine module having a rotating blade according to claim 1.

14. A jet engine, having a turbine module according to claim 13.

15. The rotating blade according to claim 5, wherein the intermediate segment, when observed in the tangential section, apart from a linear extension that is in sections, is included exclusively with the first and the second radii of curvature R.sub.1, R.sub.2.

16. A turbine module having a rotating blade ring according to claim 12.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The invention will be explained in more detail in the following on the basis of an example of embodiment, wherein the individual features in the scope of the present invention can also be essential to the invention in another combination, and wherein also no distinction is made individually between the different claim categories. Taken individually,

[0025] FIG. 1 shows schematically a turbofan engine in an axial section;

[0026] FIG. 2 shows a rotating blade with blade element and shroud in a schematic lateral view;

[0027] FIG. 3 shows the shroud of the rotating blade according to FIG. 2 in a tangential section;

[0028] FIG. 4 shows a view of a detail of FIG. 3;

[0029] FIG. 5 shows an alternative embodiment of the profiling of FIG. 4.

DESCRIPTION OF THE INVENTION

[0030] FIG. 1 shows a turbomachine 1 in a schematic view, concretely a turbofan engine. The turbomachine 1 is functionally divided into compressor 1a. combustion chamber 1b and turbine 1c; the latter comprises a high-pressure turbine module 1ca and a low-pressure turbine module 1cb. In this case, both the compressor 1a as well as the turbine 1c are each constructed of several stages; each stage is composed of a guide vane ring and a rotating blade ring. During operation, the rotating blades rotate around the longitudinal axis 2.

[0031] FIG. 2, in a lateral view, shows a rotating blade 20 of the turbine 1c, concretely of the low-pressure turbine module 1cb. The latter comprises a rotating blade element 23 and a shroud 24; it is mounted on a disk (not shown here) by way of a blade root 21. Sealing tips 25, which, for example, run into a run-in lining of the housing (not shown) during operation, are arranged radially outside on the shroud 24.

[0032] FIG. 3 shows the shroud 24 in a tangential section, wherein its axial front end 24.1 lies on the left in FIG. 2 and the axial back end 24.2 lies on the right in FIG. 2. Further, for orientation, in FIG. 3, the sealing tips 25 are shown, but they lie outside the plane of section and thus are reproduced by dotted lines. The subject is particularly directed to the profiling of the peripheral side 30 of the shroud 24. The latter is assembled with a free flank 32 and a contact flank 31 that lies opposite axially, as well as an intermediate segment 33 formed therebetween.

[0033] The intermediate segment 33 is composed of a first transition segment 33.1 that runs tangentially into the contact flank 31 and has a first curvature 41, which is greater than a second curvature 42, by which a second transition segment 33.2 runs into the free flank 32. The curvatures 41, 42 are realized here by way of a first and a second radius of curvature R.sub.1, R.sub.2, wherein the greater curvature is associated with a smaller radius, The combination of smaller and greater curvature can be of advantage, on the one hand, with respect to the mechanical stress level in the shroud 24, wherein, on the other hand, the extent of the contact flank 31 and thus attachment to the adjacent shroud is at least not essentially reduced; see the introduction to the description in detail. For orientation in FIG. 3, an axial direction 45 as well as a circumferential direction 46 are also shown.

[0034] FIG. 4 shows the groove 50 formed between the contact flank 31 and the free flank 32 once more in a detailed view (also in a tangential section). Shown further is an angle bisecting line 55 that bisects the intermediate segment 33 in the base 56 of the groove, a line that lies in the middle between contact flank 31 and free flank 32. A tangent 57 that is indicated there lies diagonally due to the asymmetric shaping, thus not at a right angle to the angle bisecting line.

[0035] FIG. 5 shows a slightly modified embodiment, in which the first and the second transition segments 33.1, 33.2 do not directly transition into one another. Instead of this, a central segment 60 is formed therebetween, which extends linearly and in each case tangentially into the two transition segments 33.1, 33.2.