COMPLEMENTARY STRUCTURE

Abstract

A method of manufacturing an annular component comprises providing an annular shell to form the outer wall of the component and a plurality of flat annular rings wherein a radially inner edge of each ring is shaped to correspond to a cross-section of the shell at a different position along its length. The method comprises attaching each ring to the ring(s) adjacent to it at a plurality of circumferentially spaced discrete positions. The method comprises deforming each flat annular ring into a corrugated three-dimensional shape, wherein the corrugations extend out of the flat plane and comprise radially defined peaks and troughs. The method comprises locating the shell within the plurality of attached, deformed annular rings. The method comprises attaching the plurality of attached, deformed annular rings to the shell to form the component, so that the plurality of attached, deformed annular rings provide structural reinforcement to the shell.

Claims

1. A method of manufacturing an annular component, the method comprising the steps of: providing an annular shell to form the outer wall of the component; providing a plurality of flat annular rings wherein a radially inner edge of each ring is shaped to correspond to a cross-section of the shell at a different position along its length; attaching each ring to the ring(s) adjacent to it at a plurality of circumferentially spaced discrete positions; deforming each flat annular ring into a corrugated three-dimensional shape, wherein the corrugations extend out of the flat plane and comprise radially defined peaks and troughs; locating the shell within the plurality of attached, deformed annular rings; and attaching the plurality of attached, deformed annular rings to the shell to form the component, so that the plurality of attached, deformed annular rings provide structural reinforcement to the shell.

2. The method according to claim 1, wherein the step of attaching each ring to the ring(s) adjacent to it is performed before the step of deforming each flat ring into a corrugated three-dimensional shape.

3. The method according to claim 2, further providing two flat annular end plates; wherein each flat annular end plate is attached to a flat annular ring, after the step of attaching each ring to the rings adjacent to it; the method further comprises the step of: pulling the two end plates away from each other in order to deform each flat annular ring into the corrugated three-dimensional shape.

4. The method according to claim 1, wherein the step of attaching each ring to the rings adjacent to it is performed after the step of deforming each flat ring into a corrugated three-dimensional shape.

5. The method according to claim 1, wherein the shape of the flat annular rings varies sinusoidally around its circumference.

6. The method according to claim 1, wherein the attachments between each two adjacent rings form a set of connections; and each set of connections is regularly, circumferentially offset from adjacent sets of connections.

7. The method according to claim 1, wherein the shell is frustoconical; and the plurality of rings are formed concentrically from a single sheet.

8. The method according to claim 7, wherein connections are left between rings that form the attachments between adjacent rings.

9. The method according to claim 1, wherein the rings are formed of a conductive material; and the attachments between rings are achieved by applying non-conductive material between adjacent rings at discrete regular locations and applying an electric current through the plurality of rings such that welding of adjacent rings occurs where the non-conductive material is applied.

10. The method according to claim 1, wherein the width of each ring in the radial direction is more than five times the thickness of the ring in the axial direction.

11. The method according to claim 1, wherein each ring forms a corrugated shape within the three-dimensional structure.

12. The method according to claim 11, wherein the distance between the peaks and troughs of the corrugations is equal to or greater than the width of each ring in the radial direction.

13. The method according to claim 1, wherein the shell is metallic; and/or the rings are metallic.

14. A bleed outlet duct comprising: an annular shell which forms an outer wall of the duct; and a plurality of flat annular rings wherein a radially inner edge of each ring is shaped to correspond to a cross-section of the shell at a different position along its length, wherein each ring is attached to the ring(s) adjacent to it at a plurality of circumferentially spaced discrete positions; wherein each flat annular ring is deformed into a corrugated three-dimensional shape, and wherein the corrugations extend out of the flat plane and comprise radially defined peaks and troughs; wherein the shell is located within the plurality of attached, deformed annular rings; and wherein the plurality of attached, deformed annular rings is attached to the shell to form the duct, so that the plurality of attached, deformed annular rings provide structural reinforcement to the shell.

15. An annular component comprising: an annular shell; a complementary structure attached to a radially outer wall of the shell and providing structural reinforcement to it; characterised in that the complementary structure is an expanded three-dimensional structure.

16. The component according to claim 15, wherein the complementary structure comprises a plurality of corrugated annular rings forming a structure extending along an axial direction of the shell.

17. The component according to claim 16, wherein the distance between the peaks and troughs of the corrugations is more than three times the width of each ring in the radial direction.

18. The component according to claim 15, wherein the width of each ring in the radial direction is more than five times the thickness of the ring in the axial direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Embodiments will now be described by way of example only, with reference to the Figures, in which:

[0059] FIG. 1 is a sectional side view of a gas turbine engine;

[0060] FIG. 2 is a sectional view of a bleed outlet duct;

[0061] FIG. 3 is an annular part with diamond web reinforcement known in the prior art;

[0062] FIG. 4 is a frustoconical annular component with an annular ring;

[0063] FIG. 5 shows concentric annular rings that could, for example, be cut from a single sheet;

[0064] FIG. 6 shows concentric annular rings with attachments between rings formed by incomplete laser cutting of the sheet material;

[0065] FIG. 7 shows concentric annular rings with attachments between rings formed by applying non-conductive material;

[0066] FIG. 8 is an annular component with a skin and a complementary structure attached;

[0067] FIG. 9a is a plan view showing a flat annular ring with a shape that varies sinusoidally around its circumference; and

[0068] FIG. 9b is a plan view showing a structure created from deformed annular rings with shapes that vary sinusoidally around their circumference.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0069] With reference to FIG. 4 there is shown a frustoconical annular component 50. Marked on the annular component 50 is a series of locations for cross sections 52 of the annular component 50. A single annular ring 54, from a set of annular rings, is shown, in isolation from the set of annular rings, to demonstrate the relationship between the ring and the annular component. The inner edge 56 corresponds with the cross section 58, as shown by dotted lines A and B.

[0070] The cross sections 52 represent the cross sections of the annular component 50 that the annular rings (one of which is shown as a singular annular ring 54) correspond to. The inside edge 56 of the single annular ring 54 matches the shape of the cross section 58. In the complete design, further annular rings would be provided (i.e. a plurality of annular rings) with each ring corresponding to a cross section 52. Cross section 60 is an example of an adjacent cross section to cross section 58. The ring 54 would therefore have an adjacent ring that corresponds to cross section 60. Cross section 58 is adjacent to cross section 60. Cross section 60 is also adjacent to another cross section (not labelled) on the other side to cross section 58.

[0071] In FIG. 4 there are 7 cross sections, but there may be greater or fewer cross sections depending on the application. In FIG. 4 the annular ring 54 shown is circular but in other embodiments it may have other shapes (for example an ellipse). The frustoconical annular component of FIG. 4 may be cylindrical or another shape.

[0072] FIG. 5 shows a series of concentric annular rings 62. Each ring is sized such that it nests inside an adjacent ring such that all the rings 62 can be formed from a single sheet of material (for example a metal) no larger than the size of the largest ring. The rings 62 in this example could be cut from a single sheet using, for example, laser cutting.

[0073] In FIG. 5, 5 rings are shown but a greater or fewer number of annular rings may be provided depending on the embodiment. The inner ring 64 corresponds with the single annular ring 54 and cross section 58 of FIG. 4. The other rings 62 each correspond to another cross section, for example the other cross sections 52 of FIG. 4.

[0074] FIG. 6 shows the concentric annular rings 62 of FIG. 5 with attachments shown between rings 66-74. The attachments between rings, for example 66, represent attachments at discrete circumferential locations.

[0075] The attachments 66-71 are evenly (e.g. regularly) circumferentially spaced around the inner edge of the largest ring 63, between the largest ring and the second largest ring. Attachments 66-71 represent a set of connections. In FIG. 6 there are four sets of connections at different radii, however in other embodiments there may be greater or fewer sets of connections. In the example shown in FIG. 6 there is a number of sets of connections equal to one less than the number of annular rings.

[0076] The attachments of FIG. 6 are formed due to the laser cutter cutting incomplete circles in the sheet. For example the gap 78 is cut by a laser cutter leaving attachments 66 and 71 on either side.

[0077] Attachment 72 is part of an adjacent set of connections to the set of connections formed by attachments 66-71. Attachment 72 can be seen to be circumferentially offset from attachments 70 and 71. In FIG. 6, the attachment 72 is offset by half the angle between attachments 70 and 71. This offset is repeated for the next set of attachments that attachments 73 and 74 form a part of. It can therefore be seen that attachment 73 and 71, and 74 and 70, are at the same circumferential position. The set of connections that attachments 73 and 74 form a part of are offset from the set of connections that 70 and 71 form a part of by one set of attachments (that attachment 72 forms a part of). In other embodiments other offsets of different angles between sets of connections may be required.

[0078] FIG. 7 shows the same arrangement of rings 62 as FIG. 6 but with an alternative type of attachment. Instead of the attachment 66 of FIG. 6 there is provided non-conductive material 80 at the discrete locations of the attachment positions. Once non-conductive material has been placed at all of the attachment positions, a voltage is placed over the structure between the outer ring 63 and the inner ring 64. The higher resistance of the non-conductive material 80 causes an increase in temperature at these points. This results in welding between the rings at the attachment positions.

[0079] FIG. 8 shows an annular component formed of a shell 90 and a complementary structure 89. The complementary structure 89 is formed of five annular rings 91-95 that have been attached to each other at attachment positions, for example position 102, and then deformed into the corrugated shape shown. The attachment position 102 is between the inside edge of one annular ring and the outside edge of an adjacent annular ring. The two end rings 98 and 100 can either be separate rings or lips of the shell 90. The complementary structure 89 is attached to the shell 90 at, for example, location 103 (and other corresponding locations) and to the end rings at locations 104.

[0080] FIG. 9a shows a plan view of a flat annular ring 120 with a shape that varies sinusoidally around the circumference. FIG. 9a shows how the radius of the annulus formed by the ring increases and decreases in a sinusoidal fashion around the circumference. Annular ring 120 can be seen to have rotational symmetry.

[0081] FIG. 9b shows a plan view of a series of the annular rings (120, 122, 124, 126, 128) of the type shown in FIG. 9a. Each ring (120, 122, 124, 126, 128) is a different diameter, for example ring 128 is the largest and ring 120 is the smallest. The annular rings in FIG. 9b have been deformed into a corrugated three dimensional shape. The corrugations are out of the flat plane of the annular ring. For example in FIG. 9b the peaks are extending out of the plane of FIG. 9b. In the example shown in FIG. 9b, all surfaces of a deformed ring can be formed of individual lines that are parallel to the flat plane of the annular ring. That is to say, the ring contains no twist. In other embodiments the ring can contain twist. In the example shown in FIG. 9b, the peaks of the corrugations correspond with the parts of the shape of the annular ring that are at the greatest radial extent of the sinusoidally varying shape of the ring. The troughs of the corrugations correspond with the parts of the shape of the annular ring that are at the least radial extent of the sinusoidally varying shape of the ring. This allows for the result that when the annular ring is deformed into a corrugated three dimensional shape, the inner edge of the annular ring conforms to a conical shape. The deformed annular ring therefore can correspond and provide support to a frustoconical shell whilst providing contact between the inner edge of the annular ring and the shell across the whole of the inner edge. In other embodiments the inner edge of the annular ring may not be shaped to contact a shell across the whole span of the inner edge, but closely follow the shape of the shell regardless.

[0082] FIG. 9b shows a structure created from five annular rings (120, 122, 124, 126, 128). The annular rings are joined together at attachments, for example attachment 130. The attachments are between the peak of one annular ring and the trough of an adjacent annular ring. The attachments in FIG. 9b are across the width of the annular ring. In other embodiments the attachments may be between a point, for example on the inner edge of an annular ring, on one annular ring and another point, for example on an outer edge of an adjacent annular ring. FIG. 9b shows eight attachments between each ring and one of the adjacent rings. These eight attachments form a set of attachments. The circumferential locations of each set of attachments are offset compared to an adjacent set of attachments.

[0083] A method of manufacturing an annular component with a shell and a complementary structure will now be described with reference to the accompanying drawings. A shell 50 is provided, for example that shown in FIG. 4. A laser cutter cuts a series of broken circles into a sheet creating the arrangement shown in FIG. 6 whereby a number of concentric annular flat rings are formed with attachments between rings forming a single structure. The single structure shown in FIG. 6 is pulled apart whereby the rings deform into rings 91-95 with corrugated shapes as shown in FIG. 8. This three dimensional structure, comprised of the corrugated rings, is then attached to the shell 90 of FIG. 8, which in this example is an embodiment of the shell 50 in FIG. 4.

[0084] An alternative method of manufacturing an annular component with a shell and a complementary structure will be described with reference to FIGS. 9a and 9b. A plurality of flat annular rings, for example annular ring 120, are provided. Each flat annular ring has a shape whose radius sinusoidally varies around the circumference. Each ring is of a different radius (e.g. average radius). Each ring is deformed into a corrugated three dimensional shape. Each ring is attached to an adjacent ring, for example a ring closest in size to it out of the plurality of rings. In the embodiment described the rings are attached by welding but in other embodiments other attachment methods may be used. The attachments may be formed, for example, by welding or using fasteners. The completed structure of attached, annular rings can then be attached to a shell.

[0085] It will be understood that the invention is not limited to the embodiments above-described and various modifications and improvements can be made without departing from the concepts described herein. Except where mutually exclusive, any of the features may be employed separately or in combination with any other features and the disclosure extends to and includes all combinations and sub-combinations of one or more features described herein.