Aircraft Turbomachine Blade and Method for Manufacturing Same Using Lost-Wax Casting

Abstract

An aircraft turbine engine blade includes at least one inner cavity for circulating a ventilation air flow and having a wall with first projecting elements oriented in a first direction and forming air flow disrupters, and at least a second projecting element oriented in a second direction different from the first direction. The second projecting element and at least one of the first projecting elements overlap each other in one area. At least one of the first projecting elements overlaps the second projecting element and has a height (H2, H4′) which is greater than that of the second projecting element in the area and greater than that of the other first projecting elements of the wall, in order to retain its disruptive function along the entire length thereof.

Claims

1. Aircraft turbine engine blade, comprising at least one inner cavity configured to circulate a ventilation air flow, the cavity comprising a wall that comprises first projecting elements oriented in at least one first direction and forming air flow disrupters, the wall further comprising at least one second projecting element oriented in at least one second direction different from the first direction, wherein the second projecting element and at least one of the first projecting elements overlap each other in an area, at least one of the first projecting elements overlapping the second projecting element and having a height greater than a height of the second projecting element in said area and which is greater than that of the other first projecting elements of the wall, to retain a disruptive function over an entire length thereof.

2. The blade according to claim 1, wherein a direction of the first projecting element is perpendicular to a direction of the second projecting element.

3. The blade according to claim 1, wherein the directions of the first and second projecting elements are inclined against one another.

4. The blade according to claim 1, wherein at least one of the first and second projecting elements has an elongate shape.

5. The blade according to claim 1, wherein only one of the first projecting elements overlaps said second projecting element and forms a cross with the second projecting element.

6. The blade according to claim 1, wherein two of the first projecting elements overlap said second projecting element and form branches on two opposite sides of the second projecting element.

7. The blade according to claim 1, wherein the or each first projecting element which overlaps said second element has a height which varies and is maximum in said area.

8. A ceramic core for the manufacture of a blade according to claim 1, by a method for manufacturing by lost-wax casting, the core comprising a part configured to form said cavity and comprising: first hollow units oriented in at least one first direction and configured to form said projecting elements, and at least one second hollow unit oriented in at least one second direction different from the first direction and forming a housing for a spacer, this second unit and at least one of the first units overlapping each other in an area, wherein the or each first unit which overlaps the second unit has a depth greater than that of the second unit in said area.

9. A method for manufacturing a blade according to claim 9.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0026] Other characteristics and advantages of the invention will appear upon reading the detailed description below, of which to understand, the appended drawings can be referred to, wherein:

[0027] FIG. 1 is a schematic, transverse cross-sectional view of a cast and of a ceramic core for the manufacture of a blade by lost-wax casting,

[0028] FIG. 2 is a schematic, axial cross-sectional view of a cast and of a ceramic cast for the manufacture of a blade by lost-wax casting,

[0029] FIG. 3 is a schematic, transverse cross-sectional view of a turbine engine blade,

[0030] FIG. 4 is a schematic, partial, perspective view of a cavity of a turbine engine blade, and illustrates an embodiment of the invention,

[0031] FIG. 5 is a very schematic view illustrating the embodiment of FIG. 4,

[0032] FIG. 6 is a partial, perspective schematic view of a cavity of a turbine engine blade, and illustrates another embodiment of the invention,

[0033] FIG. 7 is a very schematic view illustrating the embodiment of FIG. 6, and

[0034] FIG. 8 is a partial, perspective schematic view of hollow units of a core to make the cavity of the embodiment of FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

[0035] FIGS. 1 to 3 have been described above and illustrate the prior art. They also illustrate the invention insofar as the description of these figures applies to the invention.

[0036] FIGS. 4 and 5 illustrate a first embodiment of the invention. FIG. 4 shows a cavity 100 of a blade 2 which is partially visible and which can be considered as similar to that represented in FIG. 3.

[0037] The cavity 100 has a general elongated shape and is formed, thanks to a core, as mentioned above and in a known manner by a person skilled in the art who specialises in manufacturing a blade by lost-wax casting.

[0038] The cavity 100 comprises a wall 104 on which are located projecting elements 106, 108.

[0039] In the present application, by a first projecting element, referenced 106, this means an element which is configured to form an air flow disrupter. The air flow F which flows in the cavity will have to bypass this element which will create turbulences in the air flow and thus favour thermal exchanges between this air flow F and the wall 104 (FIG. 5).

[0040] An element 106 generally has a general elongated shape and can have a parallelepiped, cylindrical shape, etc.

[0041] An element 106 extends in a particular direction and the elements 106 of one same cavity 100 can extend parallel to one another. Generally, they extend in a direction which is perpendicular or inclined with respect to the direction of the flow of the air flow F in the cavity 100 to form obstacles to this flow.

[0042] In the present application, by a second projecting element, referenced 108, this means an element which results from the method for manufacturing the blade 102 and which has no particular function within the cavity 100.

[0043] This second element 108 is oriented in a second direction different from the first direction and which is generally parallel to the direction of flow of the flow F in the cavity.

[0044] As can be seen in the drawings and as this is mentioned above, elements 106, 108 can overlap each other.

[0045] In the embodiment of FIGS. 4 and 5, only one of the first elements 106 overlaps a second element 108, substantially in its centre, to form a cross. The directions of the first and second elements 106, 108 are therefore substantially perpendicular in the example represented.

[0046] The second element 108 has a height H1 which is constant. The first element 106 which overlaps the second element 108 has a height H2 which is greater than H1. The height H2 of the first element 106 is also constant. FIG. 4 allows to observe that the height H2 can be greater than the height H3 of the other first elements of the cavity which do not overlap a second element. H3 can moreover be similar to H1.

[0047] FIGS. 6 and 7 illustrate a second embodiment of the invention. FIG. 6 shows a cavity 100 of a blade 102 which is also partially visible.

[0048] The cavity 102 is similar to that of the preceding embodiment and comprises, on its wall 104, a second projecting element 108 which is also similar to that described above.

[0049] The wall 104 further comprises first projecting elements 106a, 106b different from those 106 described above.

[0050] Each element 106a, 106b has a general elongated shape and can have a parallelepiped, cylindrical shape, etc.

[0051] The elements 106a, 106b extend in directions inclined with respect to that of the element 108. The elements 106a, 106b are further inclined against one another so as to form a chevron even if they are not contiguous and are spaced from one another in the example represented.

[0052] The elements 106a, 106b are here disposed on either side of the element 108 and thus form lateral branches of the element 108. The element 106a extends in an inclined manner and joins an upper end of the element 108, while the element extends in an inclined manner and joins a lower end of the element 108.

[0053] The second element 108 has a height H1 which is constant. The elements 106a, 106b have variable heights H4, H4′. The maximum height H4′ of the elements 106a, 106b is located at the level of the ends of these elements located in the overlapping areas, while the height H4 is that of the opposite ends of these elements.

[0054] The elements 106a, 106b are presented here in the form of rails. The height H4 can be equal to the height of the other first elements of the cavity which do not overlap a second element.

[0055] The last figure partially shows a ceramic core 200 for the manufacture of a blade 102 and in particular, of a cavity 100 of this blade according to the second embodiment described above.

[0056] This core 200 comprises a part 202 configured to form the cavity 100 and comprises, on the one hand, first hollow units 206a, 206b oriented in first directions and configured to form the elements 106a, 106b, and on the other hand, at least one second hollow unit 208 oriented in a second direction different from the first directions and forming a housing for a spacer 14.

[0057] This second unit 208 and the first units 206a, 206b overlap each other in an area and these first units 206a, 206b have a depth greater than that of the second unit 208 in said area. It is therefore understood that the first units 206a, 206b are more recessed (deeper) than the second unit 208 and that these differences in depth are determined to obtain differences in height of the projecting elements 106a, 106b, 108 inside the cavity of the blade to be made.

[0058] During the manufacture of the blade by lost-wax casting, the molten metal moulded in the cast will occupy the empty spaces left by the wax and the spacers 14. The molten metal will thus occupy the space of the hollow units 206a, 206b, 208 to give the projecting elements 106a, 106b, 108 which can be seen in FIGS. 5 and 6.