CONNECTING STRUCTURE FOR LOAD TRANSFER

Abstract

A connecting structure (10) for load transfer, in particular in a gas turbine (1), including a strut (20) and at least one wall element (30) is provided. The strut (20) at one end is integrally joined to the wall element (30), and the strut (20) and the wall element (30) are enclosed by a fillet (40), at least in areas, and integrally joined to same. An elastic deformation of the involved elements of the structure during the load transfer and/or load absorption is improved in that a root section (50) that is formed by a ridge (56) and that extends from the strut (20) to the wall element (30) is situated on the fillet (40).

Claims

1. A connecting structure for load transfer, in particular in a gas turbine, the connecting structure comprising: a strut; and at least one wall element, the strut at one end being integrally joined to the wall element, and the strut and the wall element being enclosed by a fillet, at least in areas, and integrally joined to same, a root section formed by a ridge with a comb and extending from the strut to the wall element being situated on the fillet.

2. The connecting structure as recited in claim 1 wherein the root section widens the fillet on a wall element surface of the wall element by at least 5%, in particular 10%, or the root section widens the fillet on the strut surface of the strut by at least 5%, in particular 10%.

3. The connecting structure as recited in claim 1 wherein an extension of the comb between two adjacent circumferential lines of the fillet with respect to an extension of the fillet outside the root section, in particular an extension at a root boundary line, between the two circumferential lines is increased in particular by at least 1% and by at most 5%, preferably by at least 2% and by at most 4%.

4. The connecting structure as recited in claim 3 wherein the extension of the comb in an area of the root section closer to the wall element is greater than in an area of the root section closer to the strut.

5. The connecting structure as recited in claim 1 wherein the comb has a course direction and an in particular averaged root angle with respect to a transverse direction of the strut, and the root angle being in a range of −80° to +80°, in particular in the range of −45° to +45°, particularly preferably in the range of −30° to +30°.

6. The connecting structure as recited in claim 1 wherein the comb has a course direction and the root section has a root width, and the root width along a circumferential line of the fillet extends in both directions transverse to the course direction of the comb, and in both directions in each case reaches a point of maximal curvature on the circumferential line, and the root width extends over at least 10%, in particular at least 5%, particularly preferably at least 3%, and at most 15%, in particular at most 20%, particularly preferably at most 30%, of the total length of the circumferential line and/or the root width extends over at least 10%, in particular at least 5%, particularly preferably at least 3%, and at most 15%, in particular at most 20%, particularly preferably at most 30%, of a total length of the comb of the ridge of the root section or the root width, at least along 70% of a total length of the comb, has a profile that varies by less than 5%.

7. The connecting structure as recited in claim 1 wherein the root section is situated at a distance from a local highest load position at the strut, at the wall element, or at the fillet, in particular at a distance from a local highest load position in the axial direction in front of a front edge of the strut or from a local highest load position in the axial direction behind a rear edge of the strut.

8. The connecting structure as recited in claim 1 wherein the fillet is divided into two sides by a separating plane, in particular a meridian plane, and the at least one root section is situated completely on one of the two sides of the separating plane.

9. The connecting structure as recited in claim 8 wherein a plurality of root sections, in particular at least three root sections, particularly preferably four root sections, are situated at least on each of the two sides, and in particular a first root section of the plurality of root sections is situated on one side of the separating plane and a second root section of the plurality of root sections is situated on the other side of the separating plane, in particular symmetrically with respect to the first root section, and/or a third root section of the multiple root sections is situated on one side of the separating plane and a fourth root section is situated on the other side of the separating plane, in particular symmetrically with respect to the third root section.

10. The connecting structure as recited in claim 8 wherein at least an even number of root sections as root section pairs are situated on each of the two sides, and in particular the two root sections of each root section pair are situated symmetrically with respect to the spanned meridian plane and/or enclose an angle between 20° and 160° relative to one another.

11. The connecting structure as recited in claim 1 wherein three or four root sections, each formed by a ridge with a comb, and which in each case extend from the strut to the wall element, are situated on the fillet, of the three or four root sections, at least two root sections in succession, in particular in each case two root sections in succession, extending with respect to one another at an angle in the range of 80° to 170°.

12. The connecting structure as recited in claim 1 wherein the strut at one end opposite from the end is integrally joined to a further wall element and is designed, intended, or suited for load transfer between the wall element and the further wall element.

13. A gas turbine, in particular aircraft engine, including one or multiple connecting structures as recited in one of the preceding claims for load transfer, in particular in an inlet housing, outlet housing, or intermediate housing in the compressor or turbine area and/or in a bearing area, in particular one of the two wall elements being situated on the hub side of a flow channel of the gas turbine, and the other of the two wall elements being situated on the hub side or on the housing side of the flow channel, one or both of the wall elements being part of an integral, uninterrupted ring that is segmented or unsegmented in the circumferential direction, or the strut(s) being designed, intended, and/or suited for load transfer between a first and a second stator component, it being possible for one of the two stator components to be situated on the hub side of a flow channel of the gas turbine, and the other of the two stator components to be situated on the hub side or on the housing side of the flow channel.

Description

[0044] The present invention is explained in greater detail with reference to the following drawings, based on several preferred exemplary embodiments, in particular via further advantages and features.

[0045] FIG. 1 shows an overview of a schematically illustrated gas turbine in a side view with a first exemplary embodiment of a connecting structure according to the present invention;

[0046] FIG. 2 shows a second exemplary embodiment of a connecting structure according to the present invention in a top view;

[0047] FIG. 3 shows a third exemplary embodiment of a connecting structure according to the present invention in a top view;

[0048] FIG. 4 shows a fourth exemplary embodiment of a connecting structure according to the present invention in a front view;

[0049] FIG. 5 shows, in a view from above, examples of possible positions and specific embodiments of the root section with reference to a schematic drawing;

[0050] FIGS. 6a, 6b, and 6c each show further preferred exemplary embodiments with different local highest load positions relative to the root sections; and

[0051] FIG. 7 shows an example diagram of a grid that describes the fillet.

[0052] FIG. 1 shows an overview of a schematically illustrated gas turbine 1 that is designed as an aircraft engine, including a turbine intermediate housing 2 and a bearing seal housing 3, illustrated in a comparatively larger scale, in which a first exemplary embodiment of a connecting structure 10 according to the present invention is situated. Gas turbine 1 and its components and elements may be defined via the three main directions of the gas turbine, namely, axial direction Ax, which coincides with the rotational axis of the gas turbine, radial direction R, which is perpendicular to the rotational axis and extends from the inside to the outside, and circumferential direction U about the rotational axis in the rotational direction.

[0053] Connecting structure 10 includes a strut 20 as well as a lower wall element 30 and an upper wall element 30′, the two wall elements 30, 30′ being connected to strut 20 by a continuous lower fillet 40 and an upper fillet 40′, respectively. Wall elements 30, 30′ extend cylindrically in circumferential direction U. Fillets 40, 40′ enclose strut 20 and merge into corresponding wall element 30, 30′. Strut 20 has a longitudinal axis L in parallel to its longitudinal extension. In alternative specific embodiments, strut 20 and its longitudinal axis L may also be tilted obliquely to the front, to the rear, and/or to the side relative to wall element 30 and axial direction Ax. Lower wall element 30 has an outwardly curved, convex surface, whereas upper wall element 30′ has an inwardly curved, concave surface.

[0054] According to the present invention, root sections 50, 50′ are provided on the two fillets 40, 40′, respectively, so that the rigidity of fillets 40 is increased in these areas.

[0055] Line II-II shows the location of the top view used in FIGS. 2 and 3.

[0056] FIG. 2 shows a second exemplary embodiment of a connecting structure 10 according to the present invention in a top view, illustrating an elliptical strut 20, a rectangular wall element 30, and a fillet 40 that integrally joins strut 20 and wall element 30. Strut 20 is designed as a solid body. Fillet 40 encloses strut 20, and a beltlike profile of surface 45 of fillet 40 from strut 20 to wall element 30 is illustrated by multiple dashed circumferential lines h.sub.1 through h.sub.x, innermost circumferential line h.sub.1 being the circumferential line closest to the observer, and outermost circumferential line h.sub.x being the circumferential line farthest from the observer. Situated in between are further circumferential lines h.sub.2 through h.sub.x-1 in an order from inward to outward at an increasing distance from the observer. An inner edge 42 of fillet 40, which delimits strut 20 and fillet 40, at the same time is first circumferential line h.sub.1. Outermost circumferential line h.sub.x at the same time is second edge 43 of fillet 40, and adjoins wall element 30. At first edge 42, surface 45 of fillet 40 tangentially merges into a strut surface 25, and at second edge 43 tangentially merges into a wall element surface 35. Strut 20 has an axial direction Ax and a transverse direction Q, axial direction Ax coinciding with the first main direction of gas turbine 1. A front edge 22 and a rear edge 23 of strut 20 extend along strut 20 in axial direction Ax.

[0057] Connecting structure 10 and thus fillet 40 is divided into two sides 44, 46 by a meridian plane E. Four root sections 50 that are formed in each case by a ridge 56 are arranged, divided in pairs, on both sides 44, 46 of fillet 40, one pair of root sections 50 being provided in a front area, and one pair being provided in a rear area, of fillet 40.

[0058] Ridges 56 each include a comb 51, which is depicted by dotted lines. At their end-facing wall element 30, root sections 50 in each case form a protrusion 41, which in the present exemplary embodiment widens fillet 40 on surface 35 of wall element 30 by 100%. A power flow is thus advantageously displaced into the lateral area of connecting structure 10.

[0059] Comb 51 extends along lines, which in each case are lines between lined-up points with maximal curvature of circumferential lines h, and thus, of increased extension S.sub.R, as explained in greater detail below. Root sections 50 are lengthened to a greater extent toward the outside than toward the inside, so that a stress in the areas of root sections 50 close to wall element 30 is advantageously displaced.

[0060] A course direction L.sub.R of comb 51 together with transverse direction Q of strut 20 forms a root angle α.sub.QL, which in the present exemplary embodiment is 20°. It may be advantageous to vary root angle α.sub.QL. In the present exemplary embodiment, root angle α.sub.QL is constant.

[0061] As an example, a root width B.sub.R of root sections 50 that extends along a circumferential line h.sub.2, transversely with respect to comb 51, is depicted, and in particular between the two points of maximal curvature 56 on circumferential line h.sub.2 adjacent to comb 51. Further root widths B.sub.R may be defined for each root section 50 and along remaining circumferential lines h.sub.3 through h.sub.x. In the illustrated example, root sections 50 are minimally small at strut 20 at a starting point 53, i.e., of circumferential line h.sub.1. Starting point 53 of root section 50 does not have to be situated on first edge 42. Root widths B.sub.R along a comb 51, taken together and connected, form a surface 55 of corresponding root section 50, and taken together at their ends also form root boundary lines 52, illustrated as dashed-dotted lines. Width B.sub.R of root section 50 is minimal at a tip 54 of root section 50. Tip 54 of root section 50 has a maximal distance, projected onto wall element 30, of a point on fillet 40 from strut 20. In the present exemplary embodiment, a tip 54 of root section 50 and a tip 41 of a protrusion of fillet 40 coincide.

[0062] A fillet width of fillet 40 may be defined based on lined-up fillet width lines B.sub.F. A greater extension S.sub.R is present along comb 51 than along fillet width lines B of fillet 40, which likewise have a maximal curvature, but no root section. For the sake of simplicity, such fillet width lines B made up of points of maximal curvature of the circumferential lines are referred to as regular extreme lines B.sub.F,max, and in the present exemplary embodiment are situated in front of and behind strut 20 in axial direction Ax due to an elliptical shape of strut 20. Strut 20 has the basic shape of an ellipse having two points of maximal curvature at the vertices of its main axis. This contour is continued at fillet 40 and maintained along width B of fillet 40, so that fillet width lines emanating from these points result in regular extreme lines B.sub.F,max. In the present exemplary embodiment, the contour at this location could advantageously be compressed due to root sections 50 and thus the increased rigidity in the side area lateral to meridian plane E, so that approximately the same extension results as along fillet width lines B emanating from the vertices of the minor axis of the ellipse of strut 20. The curvature at these locations could occasionally be reduced, which has advantageous effects on the occurring stresses.

[0063] Extension S.sub.R of root sections 50 is increased compared to an extension S outside the root sections, in particular compared to these regular extreme lines B.sub.F,max, and in particular, by a factor of 2 in the present case. This value results from increased extension S.sub.R along comb 51 and the reduced extension along regular extreme lines B.sub.F,max. A power flow in the area of root sections 50 is thus advantageously increased, and a stress in the area of front edge 22 and of rear edge 23 of strut 20 is reduced.

[0064] FIG. 3 shows a third exemplary embodiment of a connecting structure according to the present invention. The third exemplary embodiment differs from the second exemplary embodiment in that in each case three mutually adjacent root sections 50 are situated in pairs lateral to meridian plane E. In addition, strut 20 is a hollow strut.

[0065] FIG. 4 shows a fourth exemplary embodiment of a connecting structure 10. Along front edge 22 of strut 20 that extends in parallel to radial direction R, a meridian plane E that divides connecting structure 10, and thus fillet 40, into two sides may be defined with the aid of an intersection point S of front edge 22 with first edge 42, and axial direction Ax. Two root sections 50 that have a positive influence on the rigidity of connecting structure 10, i.e., in the sense of lower material requirements at the area around front edge 22, are formed on each of the two sides of fillet 40. Root sections 50 are symmetrically situated in pairs with respect to meridian plane E.

[0066] Root sections 50 have a convex height profile along circumferential lines h. In the vicinity of strut 20, root sections 50 run out, and with fillet 40 tangentially merge into strut 20.

[0067] A circumferential line h.sub.max having a greatest curvature along all fillet width lines B of fillet 40 that intersect circumferential line h.sub.max divides fillet 40 into a first and second fillet portion 40a, 40b. An extension of second fillet portion 40b closer to the wall element along width lines B is greater than an extension of first fillet portion 40a closer to strut 20. In other words, fillet portion 40b facing wall element 30 advantageously has a flatter and wider design than first fillet portion 40a facing strut 20. The rigidity in second transition subarea 40b is thus advantageously increased, so that material may be saved at front edge 22 of strut 20 or in fillet 40.

[0068] FIG. 5 shows a schematic top view onto a connecting structure 10 with various examples of designs of root section 50. A meridian plane E that is spanned by an axial direction Ax and a front edge 22 of strut 20 divides connecting structure 10 into two sides. Beginning clockwise from the twelve o'clock position, the following embodiments are shown, it being possible for each of the root sections to be situated at any position:

[0069] 50a is a front root section situated laterally to the right, which at its end 53 facing second edge 42 [sic; 43] has a plurality of branches in a plurality of root subsections

[0070] 50b is a front root section situated laterally to the right and extending from first edge 42 to second edge 43

[0071] 50c is a center root section situated laterally to the right and extending from first edge 42 to second edge 43

[0072] 50d is a rear root section situated laterally to the right and spaced apart from first edge 42 and second edge 43

[0073] 50e are two rear root sections situated laterally to the right, both extending along a width line i between first edge 42 and second edge 43

[0074] 50f is a rear root section situated laterally to the left and extending from first edge 42 to second edge 43

[0075] 50g is a rear root section situated laterally to the left and having two root subsections 59 in the direction of second edge 43

[0076] 50h is a center root section situated laterally to the left and extending from first edge 42 to second edge 43

[0077] 50i is a front root section situated laterally to the left and extending from first edge 42 to second edge 43

[0078] 50j is a front root section situated laterally to the left and spaced apart from first edge 42 and extending to second edge 43

[0079] Root sections 50b and 50h as well as 50c and 50g form root section pairs that are situated symmetrically with respect to meridian plane E.

[0080] FIGS. 6a through 6c show examples of load positions in preferred exemplary embodiments.

[0081] In a fourth preferred exemplary embodiment in FIG. 6a, two local highest load positions 61, 62 at the front and rear in the area of front edge 22 or rear edge 23, respectively, of strut 20 have occurred and are correspondingly shown. Root sections 50 are situated at a distance from these local highest load positions, and in particular lateral to strut 20. Provided on each side of fillet [sic; strut] 20 are three root sections 50 that are situated in pairs, symmetrically with respect to root sections 50 on the opposite side of fillet 40. Strut 20 is a hollow strut.

[0082] In a fifth exemplary embodiment in FIG. 6b, compared to the fourth exemplary embodiment, in addition further local highest load positions 63 have occurred and are correspondingly shown. These are high notch stresses in the lateral area of strut 20 or of fillet 40. Root sections 50 are situated essentially centrally between load positions 61 through 63. The greatest reduction in the elastic deformation in the load case is advantageously achieved in this way.

[0083] In the sixth exemplary embodiment in FIG. 6c, a plurality of local highest load positions 64, 65 in an area of fillet 40 facing wall element 30 have occurred and are correspondingly shown. In this case, a particular branching of root section 50 into root subsections 59 is the preferred approach for reducing the elastic deformation at or around these load positions 64, 65. Local highest load positions 64, 65 may be expected to have differing intensities of elastic deformations, and increased rigidities of root sections 50 are accordingly adapted to these load cases, in particular the extension, a height of ridge 56, and/or a thickening of root sections 50. For example, local load position 65 in a corner area of fillet 40 may be expected to have a greater elastic deformation than local load position 64, which is situated closer to strut 20.

[0084] In general, it may be provided that the extension and/or a thickening of root sections 50 and/or of root subsections 59 is designed to be proportional to the expected elastic deformation at closest load position 61, 62, 63, 64, 65.

[0085] FIG. 7 shows a front view of the connecting structure with a plurality of cross-sectional planes Q.sub.1 through Q.sub.x which intersect the connecting structure, and which in the present illustration extend normally with respect to longitudinal axis L of strut 20. If longitudinal axis L has an angle with respect to wall element 30 that differs from a right angle, it is practical to appropriately correct the orientations of cross-sectional planes Q.sub.1 through Q.sub.x. Cross-sectional planes Q.sub.1 through Q.sub.x intersect fillet 40, and form circumferential lines h.sub.1 through h.sub.x at the intersection edges. All adjacent circumferential lines, projected relative to one another onto the longitudinal extension of strut 20, have same projected distance 71 as all other adjacent circumferential lines. This projected distance 71 is height gradation 71 of the grid. The magnitude of an extension S, S.sub.R is locally defined between two adjacent circumferential lines h that intersect comb 51 or a fillet width line B.sub.F, and is computed from the square root of a sum of the square of a distance 72, projected onto a circumferential plane, between two intersection points of adjacent circumferential lines h along a fillet width line B.sub.F or of comb 51, and the square of height gradation 71.

LIST OF REFERENCE SYMBOLS

[0086] 1 gas turbine [0087] 2 turbine intermediate housing [0088] 3 bearing seal housing [0089] 10 connecting structure [0090] 20 strut [0091] 22 front edge of the strut [0092] 23 rear edge of the strut [0093] 25 strut surface [0094] 30 wall element [0095] 35 wall element surface [0096] 40 fillet [0097] 40a first fillet portion facing the strut [0098] 40b second fillet portion facing the wall element [0099] 41 protrusion [0100] 42 first edge [0101] 43 second edge [0102] 44 first side of the fillet [0103] 45 surface of the fillet [0104] 46 second side of the fillet [0105] 50 root section [0106] 51 comb [0107] 52 root boundary line [0108] 53 first end of the root section [0109] 54 tip of the root section [0110] 55 surface of the root section [0111] 56 ridge [0112] 59 root subsection [0113] 61 local highest load position [0114] 62 local highest load position [0115] 63 local highest load position [0116] 64 local highest load position [0117] 65 local highest load position [0118] Ax axial direction [0119] R radial direction [0120] U circumferential direction [0121] S extension of the fillet [0122] B.sub.F fillet width [0123] B.sub.F,min minimal fillet width [0124] L.sub.R course direction of the comb [0125] B.sub.R root width [0126] S.sub.R root extension