Gas turbine blade

Abstract

The present invention relates to a blade for a gas turbine, in particular of an aircraft engine, which is produced at least in part from ceramic matrix composite with a plurality of superimposed fabric layers, wherein at least one pair of superimposed fabric layers comprises a first fabric layer that has at least one first point of interruption between two mutually facing first edges of this fabric layer, and a second fabric layer that has at least one second point of interruption adjacent to the first point of interruption between two mutually facing second edges of the second fabric layer, this second point being displaced from the first point of interruption.

Claims

1. A blade for a gas turbine composed at least in part from ceramic matrix composite with a plurality of superimposed fabric layers, wherein at least one pair of superimposed fabric layers comprises a first fabric layer that has at least one first point of interruption between two mutually facing first edges of this fabric layer, and a second fabric layer that has at least one second point of interruption adjacent to the first point of interruption between two mutually facing second edges of the second fabric layer, this second point being displaced from the first point of interruption, wherein the first fabric layer comprises at least one first cut piece of fabric that has at least one of the two first edges, and the second fabric layer comprises at least one second cut piece of fabric that has at least one of the two second edges, wherein at least one of the two cut pieces of fabric has an area of at least 100 mm.sup.2 and at most 1.Math.10.sup.4 mm.sup.2.

2. The blade according to claim 1, wherein the two cut pieces of fabric are stitched together.

3. The blade according to claim 1, wherein the second point of interruption is displaced from the first point of interruption by at least 1.5 times a diameter of a fiber bundle of the first fabric layer that is adjacent to the first point of interruption.

4. The blade according to claim 1, wherein at least one blade is configured and arranged in a turbine stage or compressor stage.

5. The blade according to claim 1, wherein the first and second cut pieces of fabric, being cut by an automated machine; the first and second cut pieces of fabric on each other in such a way that, for a first and second fabric layer that has been inserted into a die, the second point of interruption is displaced from the first point of interruption by at least 1.5 times a diameter of a fiber bundle of the first fabric layer that is adjacent to the first point of interruption, by use of the first automated machine or a second automated machine; the first and second cut pieces of fabric being stitched together by the first or second automated machine, or another automated machine; the cut pieces of fabric that have been stitched together being inserted into the die; and the ceramic matrix composite with the cut pieces of fabric that have been stitched together and inserted into the die being provided.

6. The blade according to claim 5, wherein the cut pieces of fabric, which have been stitched together and inserted into the die, surround a core, at least in part.

7. The blade according to claim 6, wherein the cut pieces of fabric are stitched together with the core by an automated machine.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

(1) Additional advantageous further developments of the present invention ensue from the dependent claims and the following description of preferred embodiments. For this purpose, in a partially schematic manner:

(2) FIG. 1 shows the production of a blade in accordance with one embodiment of the present invention in a section perpendicular to a longitudinal axis of the blade;

(3) FIG. 2 shows a plurality of fabric layers or cut pieces of fabric of the blade in a view from the top;

(4) FIG. 3 shows the production of the blade in a section perpendicular to FIG. 1;

(5) FIG. 4 shows a view from the top of cut pieces of fabric of the blade that have been stitched together; and

(6) FIG. 5 shows a core that is surrounded by the cut pieces of fabric and stitched together with them.

DESCRIPTION OF THE INVENTION

(7) FIG. 1 shows the production of a blade in accordance with one embodiment of the present invention in a section perpendicular to a longitudinal axis of the blade.

(8) For this purpose, first of all, fabric for a ceramic matrix composite is cut by an automated machine (not illustrated), the cut pieces of fabric are superimposed on one another by the same automated machine, and subsequently they are stitched together by this automated machine or by another automated machine.

(9) For this purpose, FIG. 4 shows a view from the top of an excerpt of cut pieces of fabric that have been stitched together, in which the fiber bundles 50, which form the fabric or the fabric layers thereof, the filaments or (single) fibers 51, which comprise these fiber bundles 50, and the (fixing) stitches 60 are indicated. In the excerpt of FIG. 4, only a top fabric layer with a cut piece of fabric 10 can be seen; in the view from the tope in FIG. 2, in contrast, three of the superimposed fabric layers of cut pieces of fabric 10, 20, 30, together with the (fixing) stitches 60, with which they are stitched together, can be seen.

(10) The fabric layers or cut pieces of fabric 10, 20, 30 that have been stitched together are wound around a core 100 and stitched together with it by (fixing) stitches 61, as indicated in FIG. 5.

(11) Subsequently, the core 100 and the fabric layers or cut pieces of fabric 10, 20, 30 that have been stitched together with it and surround it are inserted into a reusable mold 101, 102, which is then closed, as indicated in FIG. 1 by closing arrows.

(12) In this state, adjacent points of interruption between the edges 11, 21, 31, 41 of the superimposed fabric layers or cut pieces of fabric 10, 20, 30, and 40 are displaced away from and with respect to one another perpendicular to the wall thickness of the fabric layers, so that a chain of points of interruption that are displaced from or against or toward one another results between the edges 11, 21, 31, 41, this being illustrated in a highlighted manner in FIG. 3.

(13) The fabric layers or cut pieces of fabric are already superimposed on one another by the cutting and stacking machine (and stitched together by this machine or by the other automated machine) in such a way that, in the state shown in FIGS. 1, 3, respective pairs (10, 20), (20, 30), and (30, 40) of superimposed fabric layers each have a first fabric layer 10, 20, and 30, respectively, which has at least one first point of interruption between two mutually facing first edges 11, 21, and 31, respectively, of this fabric layer, and a second fabric layer 20, 30, and 40, respectively, which has at least one second point of interruption adjacent to the first point of interruption between two mutually facing second edges 21, 31, and 41, respectively, of the second fabric layer, which is displaced from the first point of interruption (in each case, in the same direction).

(14) In this state, a ceramic matrix composite with cut pieces of fabric that have been stitched together and inserted into the reusable mold is produced and, in this way, a blade is produced, in particular by a polymer or the like that contains Al, Si, and/or C atoms.

(15) Subsequently, the reusable mold is opened and the blade is removed, this being indicated by the removal direction arrow in FIG. 3. The CMC blade can then be finished by pyrolysis or baking.

(16) Even though exemplary embodiments have been discussed in the preceding description, it is noted that a large number of modifications are possible. Moreover, it is noted that the exemplary embodiments are merely examples, which are not intended to limit the protective scope, the applications, and structure in any way. Instead, the preceding description provides the person skilled in the art with a guideline for implementing at least one of the exemplary embodiments, whereby diverse changes, in particular in regard to the function and arrangement of the described structural parts, can be made, without leaving the protective scope, as ensues from the claims and the combinations of features equivalent to said claims.