Gas turbine moving blade

Abstract

A moving blade for a turbine or compressor stage of a gas turbine is provided, including a vane (10) and a radially outer shroud (20), for at least one contour point (P.sub.K) of an outer contour of a profile cross section (P) of the vane at a radial outer gas channel boundary, the wall thickness of the shroud at at least one edge point (P.sub.R) of the shroud, whose connecting line (V), including the contour point with a normal (N), which is perpendicular to the outer contour of the profile cross section in the contour point, encloses an angle (σ), which is no more than 5°, is less than a wall thickness of the shroud at the contour point, the wall thickness of the shroud decreasing strictly monotonously along the connecting line.

Claims

1. A moving blade for a turbine or compressor stage of a gas turbine, comprising: a blade; and a radially outer shroud, for at least one contour point (P.sub.K) of an outer contour of a profile cross section of the blade at a radially outer gas channel boundary, a wall thickness of the shroud at at least one edge point (P.sub.R) of the shroud is less than a wall thickness of the shroud at the at least one contour point, wherein a connecting line (V), which connects the at least one contour point with the at least one edge point, intersects the at least one contour point and encloses an angle (σ) of no more than 5° with a normal (N) perpendicular to the outer contour of the profile cross section at the at least one contour point, and wherein the wall thickness of the shroud decreases strictly monotonically along the connecting line, wherein the at least one contour point (P.sub.K) is located at a junction between the blade and the shroud; and the shroud having two opposing end faces in a circumferential direction, at least one of the end faces of the shroud in the circumferential direction having a cam having an uppermost cam point (O) in the circumferential direction and a groove having a lowermost groove point (U) in the circumferential direction forming an end face surface, wherein the wall thickness of the shroud at at least one edge point between the cam and the groove, the wall thickness of the shroud at at least one edge point on a side of the cam facing away from the groove and the wall thickness of the shroud at at least one edge point on a side of the groove facing away from the cam is smaller than the wall thickness of the shroud at the uppermost cam point and/or the lowermost groove point.

2. The moving blade as recited in claim 1 wherein the wall thickness of the shroud at the at least one edge point is no more than 70% or at least 5% of the wall thickness of the shroud at the at least one contour point.

3. The moving blade as recited in claim 1 wherein for a second contour point of the outer contour of the profile cross section, the wall thickness of the shroud at a second edge point of the shroud, wherein a second connecting line intersects the second contour point with a second normal perpendicular to the outer contour of the profile section and wherein the second connecting line and the second normal form an angle of no more than 5°, is less than a wall thickness of the shroud at the second contour point wherein the second contour point is located at a junction between the blade and the shroud.

4. The moving blade as recited in claim 3 wherein the wall thickness of the shroud at the second edge point is no more than 70% or at least 5% of the wall thickness of the shroud at the second contour point, or the wall thickness of the shroud decreases monotonically along the second connecting line.

5. The moving blade as recited in claim 3 wherein the wall thickness of the shroud along the second connecting line decreases strictly monotonically.

6. The moving blade as recited in claim 1 wherein the moving blade is at least partially manufactured with an additive manufacturing method.

7. The moving blade as recited in claim 6 wherein the additive manufacturing method includes selective laser melting.

8. The moving blade as recited in claim 1 wherein the shroud has at least one depression.

9. The moving blade as recited in claim 8 wherein the at least one depression is on a side facing away from the gas channel boundary.

10. The moving blade as recited in claim 1 further comprising at least one sealing rib situated on a side of the shroud facing away from the gas channel boundary.

11. A turbine or compressor stage for a gas turbine comprising at least one moving blade as recited in claim 1.

12. A gas turbine comprising at least one turbine or compressor stage as recited claim 11.

13. An aircraft gas turbine engine comprising the gas turbine as recited in claim 12.

14. A method for manufacturing the moving blade as recited in claim 1 comprising: at least partially manufacturing the moving blade with an additive manufacturing method.

15. The method as recited in claim 14 wherein the method includes selective laser melting.

16. The moving blade as recited in claim 1 wherein the shroud includes, on a side facing away from the gas channel boundary, a pair of depressions.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantageous refinements of the present invention are derived from the subclaims and the following description of preferred embodiments. In a partially schematic illustration:

(2) FIG. 1 shows a perspective view of one part of a moving blade according to one embodiment of the present invention;

(3) FIG. 2 shows a top view of the moving blade radially from the outside; and

(4) FIG. 3 shows a sectional view of the moving blade radially from the inside.

(5) FIG. 4 shows the thickness between P.sub.K and P.sub.R in FIG. 3.

DETAILED DESCRIPTION

(6) FIG. 1 shows a perspective view of one part of a moving blade according to one embodiment of the present invention, including one part of a vane 10 and a radially outer shroud 20 (at the top in FIG. 1); FIG. 2 shows a top view of the moving blade or its shroud 20 radially from the outside, in which pocket-like depressions 21 as well as two sealing ribs 22 are apparent.

(7) FIG. 3 shows a sectional view of the moving blade radially from the inside, i.e. a sectional view of its hollow vane 10.

(8) It is apparent that the two end faces of the shroud each have a cam or lobe in the circumferential direction, i.e., the left end face in FIG. 3 and the right end face in FIG. 3, which has a top cam point O in the circumferential direction and a groove having a bottom groove point U in the circumferential direction.

(9) In each case, the wall thickness of shroud 20 is slightly greater at the cams and grooves than in the areas axially adjacent thereto (vertically in FIG. 3, 30 in FIGS. 1 and 4), so that, in particular the wall thickness at at least one edge point between the cam and the groove and/or at at least one edge point on a side of the cam facing away from the groove (left: bottom; right: top in FIG. 3) and/or at at least one edge point on a side of the groove facing away from the cam (left: top; right: bottom in FIG. 3) is less than at the particular cam point and groove point.

(10) Normal N in contour point P.sub.K, which is perpendicular to outer contour P and passes through an edge point of the gas channel-side surface of shroud 20, which is viewed from above in FIG. 3, is plotted in FIG. 3 as an example of a contour point P.sub.K of an outer contour of a profile cross section P of vane 10 at a radially outer gas channel boundary of the shroud.

(11) A normal cone around this normal N is marked by C, which includes half a cone or opening angle Σ of 15°.

(12) For at least 50% of all edge points of shroud 20 or its gas channel-side surface within this normal cone C, of which one edge point P.sub.R as well as its connecting line V, including contour point P.sub.K, is plotted by way of example in FIG. 3, a wall thickness of shroud 20 along the particular connecting line, including contour point P.sub.K, decreases and/or, at the edge point itself, is between 5% and 70% of a wall thickness of shroud 20 at contour point P.sub.K. (FIG. 4).

(13) Accordingly, angle σ enclosing connecting line V of an edge point P.sub.R of this type, with normal N, is smaller than or equal to half the cone or opening angle Σ of 15° in terms of absolute value.

(14) The wall thickness profiles or conditions explained above by way of example for a contour point P.sub.K of outer contour P plotted in FIG. 3 apply to at least 50% of all contour points of outer contour P.

(15) While the description above explains exemplary embodiments, it should be pointed out that a large number of modifications are possible. Moreover, it should be pointed out that the exemplary embodiments are only examples which are not intended to limit the scope of protection, the applications and the design in any way. Rather, the description above gives those skilled in the art a guideline for implementing at least one exemplary embodiment, various modifications being possible, in particular with respect to the function and arrangement of the described components, without departing from the scope of protection as it is derived from the claims and feature combinations equivalent to the claims.

LIST OF REFERENCE NUMERALS

(16) 10 vane 20 shroud 21 depression 22 sealing rib C normal cone N normal O (top) cam (point) P outer contour of a profile cross section P.sub.K contour point P.sub.R edge point R edge U (bottom) groove (point) V connecting line Σ half-cone angle σ angle between normal N and connecting line V