EP3309360B1 - Blade assembly for a gas turbine engine - Google Patents

Description

The invention relates to a blade assembly for an engine with a blade carrier with a plurality of blades.

Such a blade assembly is for example part of a compressor or a turbine of the engine, in particular of a gas turbine engine. The blades are thereby provided along a circular line about a central axis of the blade assembly, which central axis usually coincides with a rotational or central axis of the engine. The blade carrier, on which the blade is integrally formed or are fixed to the separately manufactured blades via a respective blade root, has a with respect to the blades radially inwardly in the direction of the central axis extending support portion. This support portion usually forms a part of a disk body, which - taking into account the available space - is formed comparatively large area in order to withstand the loads occurring during operation of the engine caused by the rapid rotation of the blade assembly about the central axis. The higher the speed of rotation of the blade carrier with the blades and thus the load on the blade carrier, the larger the carrier portion and consequently the weight of the blade carrier.

From the DE 101 63 951 C1 and DE 102 18 459 B3 is proposed for reducing the weight of a rotor blade assembly and a rotor comprising the same, at a joint portion of the beam portion, a stiffening structure having first and second metal matrix composite (MMC) stiffening members at the ring - or disk-shaped blade carrier provide. Depending on a stiffening element is designed as a fiber reinforced MMC ring and arranged on a respective end face of the blade carrier. Thus, for example, two MMC rings are defined in mirror image at a connecting region of a radially inwardly extending support section of a blade carrier, namely on a first front end side and on a second rear end side of the blade carrier. Due to the additional stiffening elements in the form of the MMC rings, the blade carrier can be acted on with a smaller radial extension of the carrier section with higher rotational speeds and thus higher load capacity. In this case, the weight of the blade carrier is significantly lower than with a blade carrier of the same load carrying capacity with a larger carrier section through the MMC rings.

In the in the DE 101 63 951 C1 and DE 102 18 459 B3 proposed blade assemblies, the stiffening elements in the form of MMC rings are independently of each other positively fixed to one end face of the support portion and optionally additionally shrunk onto an axially extending projection of the connecting portion. Each MMC ring is axially secured separately on the respective end face of the support section and arranged on a radially outwardly facing transverse direction above the associated axially extending projection on the connection region of the support section. The fixation and in particular axial securing of the individual stiffening elements in the form of the MMC rings is thus comparatively complicated. Furthermore, the manufacture of the blade carrier with the connecting region, which is additionally intended to integrate a positive axial securing possibility, is complicated and associated with relatively high costs. Other comparable blade assemblies go from the US 5,660,526 A , the US 3,610,777 A and the US 1,325,208 A out.

The invention is therefore based on the object to provide an improved in this respect blade assembly, with which the aforementioned disadvantages are avoided or at least reduced.

This object is achieved with both a blade assembly of claim 1 and a blade assembly of claim 12.

According to a first aspect of the invention, a rotor blade assembly for an engine with a ring segment or disk segment-shaped blade carrier having a plurality of rotor blades is proposed in which at least two, first and second reinforcing elements of a reinforcing structure fixed to a connecting region of a carrier section of a blade carrier are not only connected to the connecting region but the first and second stiffening elements are also additionally connected to each other.

As a result of the additional connection of the stiffening elements arranged on different end sides of the blade carrier, an axial securing of the stiffening elements to each other and to the blade carrier is achieved without each individual stiffening element itself having to be axially secured separately on the carrier section of the blade carrier. The inventive solution according to the first aspect of the invention is based on the basic idea that at the connecting region of the blade carrier - preferably to a radially extending with respect to the central axis transverse direction symmetrically configured and opposing - stiffening elements are arranged on opposite first and second end faces of the blade carrier, the by their additional connection with each other axially (relative to the central axis) are secured.

The axial securing of both stiffening elements of the stiffening structure is in this case realized in at least one connecting device with at least one separate connecting element which directly connects the two stiffening elements arranged at different end sides and secures them axially against one another. In this way, none of the stiffening elements should be axially displaceable relative to the other stiffening element. Both stiffening elements are thus held in an intended position on the support portion.

The inventive solution is basically independent of whether the blades are made separately and fixed to the blade carrier or the blades are integrally formed with the blade carrier and the blade assembly is thus made in bling or blisk construction. In one embodiment, for example, the ring segment or disk segment-shaped blade carrier is integrally formed with at least one blade.

An above-mentioned separate connecting element for the connection of the arranged on different end faces of the blade carrier first and second Stiffening elements together extends in a variant by a connection opening in the support portion. This connection opening can be a passage opening, for example in the form of a bore, through the blade carrier above the connection area, ie, around a passage opening which is spaced in a radially outward direction from the connection area. The at least one separate connecting element then extends, for example, through such a connecting opening of the blade carrier in order to fix the two reinforcing elements axially relative to one another. Not only the two stiffening elements can be fixed to one another via the at least one connecting element of the connecting device extending through the carrier section, but also the two stiffening elements on the carrier section.

In one embodiment variant, the at least one separate connecting element of the connecting device extends through a connecting opening in the carrier section in order to connect the first and second reinforcing elements to one another. The connecting element can in this case be designed, for example, in the form of a screw bolt and furthermore extend through a respective radially projecting connecting web of the first and second reinforcing elements. Furthermore, it is provided that the rotor blade assembly according to the invention along a circumferential direction around the central axis comprises a plurality of adjacent ring segment-shaped or disk segment-shaped blade carrier, each having at least one blade, which are connected at each end face with a common - for example, annular - stiffening element of the stiffening structure via a plurality of bolt connections , Thus, the connecting means of the blade assembly not only serve the fixation of the two first and second stiffening elements together, but also the fixing of the two first and second stiffening elements to a plurality of ring segment-shaped or disk segment-shaped blade carriers and a coupling of the individual ring segment-shaped or disk segment-shaped blade carrier with each other. Accordingly, an anti-rotation device for the stiffening elements on the one hand and the blade carrier on the other hand is also provided.

In one embodiment, the connecting device of the blade assembly is set up and provided to connect the blade assembly with a connecting member via which the blade assembly with another Blade assembly is rotatably connected, which is axially offset within the engine along the central axis. Thus, individual blade rows, which are each formed by a blade assembly, arranged in a multi-stage compressor or in a multi-stage turbine of the engine behind each other and rotatably connected to each other. In the aforementioned embodiment variant, a connecting component for the non-rotatable connection of individual axially offset blade rows is now fixed via a connecting device on a blade carrier, which is also used to connect the two arranged on different end faces of the blade carrier first and second stiffening elements together and preferably to fix each other and the blade carrier.

The connecting member is in this case, for example, sleeve-shaped and each with an annular mounting flange formed on each end face, via which the connecting member is fixed to a blade assembly. Alternatively, a plurality of respective sleeve segment-shaped connecting components may be provided to non-rotatably connect two rows of blades in the region of a ring segment or disk segment-shaped blade carrier or in the region of a plurality of ring segment or disk segment-shaped blade carrier.

In a possible variant, a separate connection element of the connection device, for example a plug-in bolt or a threaded bolt, extends both through a connection opening in the support section and through a connection opening in the connection component. For example, the connection opening of the connection component is a through-hole in a flange section of the connection component.

In one embodiment, it is provided that at least the first or second stiffening element is annular. In a further development, both stiffening elements are annular. The annular design of a single stiffening element per end face has over several, for example, ring-segment-shaped stiffening elements per end face the advantage of easier and faster installation.

For weight reduction, in one embodiment, at least one of the first and second stiffening elements is at least partially made of a metal matrix composite material (English: "metal matrix composite", short: "MMC") produced. Here, at least one of the first and second stiffening elements may comprise an externally sheathed core of a metal matrix composite material. The core can for example consist of a reinforced titanium in MMC construction, ie, in particular of a titanium matrix with ceramic reinforcement.

In one embodiment variant, the blade carrier on the rotor blade assembly-together with other ring segment or disk segment-shaped blade carriers-has a central passage opening extending axially relative to the center axis, which is radially bounded by inner edges of the carrier sections of the individual blade carriers. A formed of a metal matrix composite portion of the first or second stiffening member extends axially below such an inner edge of the support portion of a ring segment or disk segment-shaped blade carrier. Accordingly, it is provided in such a variant that the radially inner edge of the support section, which surrounds the preferably centrally provided through opening of the blade assembly is at least partially bordered by the at least one stiffening element, for example, in cross-section L-shaped bordered, and a portion of Stiffening element extends relative to a radially outwardly facing transverse direction below the connection region. The metal matrix composite formed portion of the first or second face first or second stiffening element thus extends below the inner edge toward the other face and thus provides support below that inner edge by the metal matrix composite. The extension of the metal matrix composite material in the axial direction below an inner edge of the carrier section can thus serve as an additional support below the at least one blade and the circumferentially encircling blade row formed therewith and lead to a more robust stiffening structure.

In one embodiment, the connecting region forms at least one axial projection, which is encompassed by a first or second stiffening element in a form-fitting manner, so that the axial projection is at least partially received between a radially outer and a radially inner portion of this stiffening element. Thus, an axially protruding portion of the connecting portion extends between a radially outer and a radially inner portion of the stiffening member. The axial projection may here be formed locally web-like protruding on the connection region and for example between the two Sections of the stiffening element to be received in a groove-shaped recess of the stiffening element. The positive encircling an axial projection of the connecting region through at least one of the stiffening elements not only allows an improved force introduction into and support by the respective stiffening element, but also an improved connection of the respective stiffening element to the connecting region of the blade carrier. As a result, the stiffening element can be simply pushed or pushed axially onto the end face of the blade carrier and onto the at least one axial projection, for example, and is held radially secured on the blade carrier via the positive encompassing of the axial projection.

As an alternative or in addition to a positive encompassing of an axial projection of the connecting region, the blade carrier together with further ring segment or disk segment-shaped blade carriers of the blade assembly may have a passage opening extending axially relative to the central axis, which is radially bounded by an inner edge of the carrier section, and may be a first or second stiffening element of the stiffening structure with at least a portion extending below this inner edge of the connecting region axially. A first or second stiffening element of the stiffening structure thus extends here with at least one section axially on the inner edge of the connecting area along an end face in the direction of the other end face of the blade carrier. Regardless of the use of a metal matrix composite - and particularly regardless of the design discussed above, where a portion of the metal matrix composite stiffener extends axially below an inner edge - the extent of the stiffener beneath the radially inner edge of the blade carrier may be limited an improved support and stiffening of the blade carrier can be achieved in the region of the support section.

The formation of at least one axial and by a stiffening element positively encompassed connection region as well as the axial extent of at least a portion of a first or second stiffening element below an inner edge of the connection region to improve the mountability of the stiffening structure and the load capacity of the blade carrier are otherwise advantageous with an additional connection the arranged on different end faces of the blade carrier first and second stiffening elements combined, but nevertheless also independently thereof implemented.

Accordingly, according to a second aspect of the invention, a blade assembly for an engine having at least one annular segment or disk segment-shaped blade carrier having a plurality of blades is proposed in which a stiffening structure is provided having at least one stiffening element on a first or second end face of the blade carrier. In this case, the connection region according to the second aspect of the invention forms at least one axial projection which is encompassed by the at least one stiffening element so that the axial projection is at least partially received between a radially outer and a radially inner portion of the stiffening element. As an alternative or in addition, according to the second aspect of the invention, it is provided that the blade assembly has a passage opening extending axially relative to the central axis of the blade assembly, which is radially delimited by an inner edge of the carrier section, and the at least one reinforcing element of the reinforcing structure having at least one section below this inner Edge of the connection region extends axially, ie from one end face in the direction of the other end face.

An axial projection of the connection region can basically extend essentially parallel to the central axis and therefore substantially perpendicular to a radially extending end face of the carrier section. However, the axial projection can also assume a deviating from 90 ° angle to the front side.

Furthermore, a transition region between a substantially radially extending end-face support surface at the connection region and one end of the projection integrally formed therewith may be concavely curved. The degree of curvature and thus the course of a straight line to this transition region can be chosen differently depending on the engine and / or position of the blade assembly, depending on how strong the forces occurring at the connection area and with which force components, for example, this run radially and tangentially , For example, a straight line extends at the transition regions at an angle of 0 ° to 45 ° to the radial direction. The degree of curvature and thus the included angle can be done, for example, depending on the manufacturing material used for the stiffening element. In particular, with respect to a metal matrix composite and the fibers provided herein, which are circumferentially higher loadable about the central axis than in a tangential direction, a smaller angle and thus a stronger concave curvature for the transition region (and thus a less "soft" transition between face and projection) offer.

The at least one axial projection may be part of a cross-sectionally T-shaped, I-shaped or fir-tree-shaped profile of the connection region. In a T-shaped profile, two projections extending axially in opposite directions are integrally formed at the connecting portion. Accordingly, in an I-shaped, i.e. cross-sectional profile of a double-T beam, there are two radially spaced pairs of such two axially extending projections in opposite directions. In a fir tree-shaped profile, at least two or three pairs arranged radially one above the other and spaced apart from each other are provided in opposite directions of axially extending projections, the axial extent of which gradually decreases or increases along a radial direction.

A T-shaped, I-shaped or fir-tree-shaped profile of the connecting region extends in a variant in the circumferential direction about the central axis. In a development, the connecting region of the ring segment or disk segment-shaped blade carrier is provided with a T-shaped, I-shaped or fir-tree-shaped profile extending over the entire length of the blade carrier in the circumferential direction.

In particular, in the case of a fir-tree-shaped cross-sectional profile of the connecting region, it is possible to arrange, for example, an annular reinforcing element on each end face of the blade carrier, which is provided with a correspondingly corresponding cross-sectional profile as a counterpart and engages around a plurality of axial projections, which are defined by the fir-tree-shaped cross-sectional profile of the connecting region. By means of such a connection between a respective stiffening element and the connecting region of the blade carrier, the radial loads occurring during operation of the engine can be introduced more efficiently from the blade carrier into the stiffening structure. Here, the forces are also introduced at different radial locations in the stiffening structure and thus distributed, so that the power transmission between the blade carrier and the stiffening structure is improved. The connection and secure fixation of the stiffening structure on the blade carrier is considerably simplified.

In one possible development, sealing elements and / or cooling openings can be provided on an axial projection of the connection region, in particular on an axial projection of a T-shaped, I-shaped or fir-tree-shaped cross-sectional profile of the connection region. Cooling openings are then used, for example, to supply cooling air to the blade carrier.

With a blade assembly according to the invention both according to the first and the second aspect of the invention, in particular a gas turbine engine can be provided in which one or more rows of blades of a compressor and / or one or more rows of blades of a turbine compared to previously conventional in practice blade rows significantly reduced in terms of their weight However, the assembly of the stiffening structure and its axial securing is comparatively easy. In this case, one blade row each forming blade assemblies, each having a plurality of ring segment-shaped or disk segment-shaped blade carrier and according to the invention a stiffening structure fixed thereto, arranged axially behind one another and rotationally fixed to each other, in particular via an axially extending connecting member or a plurality of connecting components with at least one stiffening element of a stiffening structure are connected. Of course, however, a combination of an inventively designed blade assembly for the formation of a blade row with another, not inventively designed blade assembly of another blade row is possible.

The attached figures exemplify possible embodiments of the invention.

Figur 1

ausschnittsweise und in Schnittdarstellung einen Teil einer Turbine eines Gasturbinentriebwerks mit zwei Ausführungsvarianten einer erfindungsgemäßen Laufschaufelbaugruppe;

Figur 2

eine vergrößerte Einzeldarstellung eines Verbindungsbereichs eines Schaufelträgers der Laufschaufelbaugruppe mit einer hieran festgelegen Versteifungsstruktur und einer Anbindung an zwei jeweils axial versetzt angeordneten vorderen und hinteren Laufschaufelbaugruppe;

Figur 3

schematisch eine Vorderansicht auf die Laufschaufelbaugruppe;

Figuren 4A-4B

in vergrößerter Darstellung ausschnittsweise einen Verbindungsbereich eines Schaufelträgers mit unterschiedlichen Varianten einer hieran angeordneten Versteifungsstrukturen mit MMC-Versteifungsringen;

Figuren 5A-5B

ausschnittsweise und in geschnittener perspektivischer Ansicht Ausführungsvarianten eines Schaufelträgers einer erfindungsgemäßen Laufschaufelbaugruppe mit einem tannenbaumförmigen Profil des Verbindungsbereiches, wobei der Schaufelträger einerseits integral hiermit ausgebildete Laufschaufeln (Figur 5A) aufweist und andererseits für separat hergestellte und hieran zu fixierende Laufschaufeln vorgesehen ist (Figur 5B);

Figur 6

in geschnittener und vergrößerter Ansicht eine Variante eines Verbindungsbereichs des Schaufelträgers mit tannenbaumförmigem Profil;

Figur 7

ausschnittsweise und in geschnittener Darstellung eine aus dem Stand der Technik bekannte Ausbildung von Laufschaufelreihen einer Turbine eines Gasturbinentriebwerks;

Figuren 8

eine Querschnittsansicht eines Turbofan-Triebwerks, bei dem eine Ausführungsvariante einer erfindungsgemäßen Laufschaufelbaugruppe im Bereich eines Verdichters und/oder im Bereich einer Turbine zum Einsatz kommt.

Hereby show:

FIG. 1

a partial and sectional view of a portion of a turbine of a gas turbine engine with two embodiments of a blade assembly according to the invention;

FIG. 2

an enlarged detail view of a connecting portion of a blade carrier of the blade assembly with a stiffening structure fixed thereto and a connection to two each axially offset front and rear blade assembly;

FIG. 3

schematically a front view of the blade assembly;

Figures 4A-4B

in an enlarged view fragmentary a connecting portion of a blade carrier with different variants of a stiffening structures arranged thereon with MMC stiffening rings;

Figures 5A-5B

Sectional and sectional perspective view of embodiments of a blade carrier of a blade assembly according to the invention with a fir-tree-shaped profile of the connecting region, wherein the blade carrier on the one hand integrally hereby formed blades ( FIG. 5A ) and on the other hand provided for separately manufactured and thereto to be fixed blades ( FIG. 5B );

FIG. 6

in a sectioned and enlarged view of a variant of a connecting portion of the blade carrier with fir-tree-shaped profile;

FIG. 7

a section and a sectional view of a known from the prior art training of blade rows of a turbine of a gas turbine engine;

FIGS. 8

a cross-sectional view of a turbofan engine, in which an embodiment of a blade assembly according to the invention in the region of a compressor and / or in the region of a turbine is used.

The FIG. 8 illustrates schematically and in section a gas turbine engine T, in which the individual engine components along a rotational axis or center axis M are arranged one behind the other and the engine T is designed as a turbofan engine. At an inlet or intake E of the engine T, air is drawn in along an inlet direction R by means of a fan F. This arranged in a fan housing FC fan F is driven by a rotor shaft S, which is rotated by a turbine TT of the engine T in rotation. In this case, the turbine TT adjoins a compressor V, which, for example, is a low-pressure compressor 11 and a high pressure compressor 12, and optionally also a medium pressure compressor. On the one hand, the fan F supplies air to the compressor V and, on the other hand, a secondary flow channel or bypass channel B for generating the thrust. The bypass channel B in this case extends around a compressor V and the turbine TT comprehensive core engine, which includes a primary flow channel for the supplied through the fan F the core engine air.

The air conveyed into the primary flow passage via the compressor V enters a combustion chamber section BK of the core engine in which the driving power for driving the turbine TT is generated. For this purpose, the turbine TT has a high-pressure turbine 13, a medium-pressure turbine 14 and a low-pressure turbine 15. The turbine TT thereby drives the rotor shaft S and thus the fan F via the energy released during combustion in order to generate the required thrust via the air conveyed into the bypass duct B. Both the air from the bypass passage B and the exhaust gases from the primary flow passage of the core engine flow through an outlet A at the end of the engine T. The outlet A in this case usually has a discharge nozzle with a centrally arranged outlet cone C.

Both in the area of the (axial) compressor with its low-pressure compressor 11 and its high-pressure compressor 12 and in the area of the turbine TT, rotating blade assemblies are known to be used about the central axis M, each having a blade row and in which the blades on a ring-shaped or disc-shaped Blade carrier are provided. The ring-shaped or disk-shaped blade carrier can in principle be integrally bladed and thus be manufactured in bling or blisk construction. Alternatively, the fixing of individual blades via their respective blade root on a ring-shaped or disk-shaped blade carrier is possible. For this purpose, for example, a blade root is inserted axially into a mounting groove of the blade carrier and axially secured to the respective blade carrier.

Based on FIG. 7 By way of example, a plurality of rotor blade assemblies 2a, 2b and 2c of the turbine TT arranged one behind the other along the central axis M are illustrated. The Indian FIG. 5 shown section shows only a part above the central axis M in the region of the medium-pressure turbine 14 or the low-pressure turbine 15. The individual blade assemblies 2a, 2b and 2c are non-rotatably connected via flange 4.1 and 4.2 together. Furthermore, each blade assembly 2a, 2b and 2c each have a ring-shaped or disc-shaped blade carrier 23, 24 or 25 on the individual Blades 20, 21 or 22 of a blade row along a circular line about the central axis M arranged one behind the other and fixed to the respective blade carrier 23, 24 or 25 via a blade root 200, 210 or 220 of a blade 20, 21 or 22. In the axial direction along the central axis M while blade rows of blade assemblies 2a, 2b and 2c alternate with fixed vanes rows. The guide blade rows each have guide vanes 30 or 31, which are also peripherally arranged circumferentially along a circular line about the central axis M.

Due to the high speeds and concomitant loads, each blade carrier 23, 24 or 25 of a prior art blade assembly 2a, 2b or 2c has a radially inwardly extending beam portion 230, 240 or 250. A disk-shaped support portion 250 of the rear blade assembly 2c serves, for example, for the rotatable mounting of the rotatably connected blade assemblies 2a, 2b and 2c. In the support portion 230, 240 of two - with respect to the flow direction through the engine T - front blade assemblies 2a and 2b, a central through hole O1 or O2 is provided, especially in the form of a bore, especially for weight reduction. With regard to the necessary installation space of the blade assemblies 2a and 2b and their weight, it is above all decisive which radial extent the blade carriers 23 and 24 have in order to be able to withstand the loads occurring during operation.

In the different variants of a solution according to the invention, for example, in the FIG. 1 by way of example on two blade assemblies 2a and 2b of the turbine TT are illustrated, a significant reduction of the radially extending support portions 230 or 240 by the provision of a respective stiffening structure 5a or 5b is achieved. Each stiffening structure 5a or 5b has two annular stiffening elements in the form of (MMC) stiffening rings 50 and 51, which are arranged opposite one another on the end faces of the respective blade carrier 23 or 24. The stiffening rings 50 and 51 are on the one hand directly connected to each other - preferably via at least one additional connecting element. On the other hand, both stiffening rings 50, 51 each surround a connection region 231 or 241 of the respective support section 230 or 240 in a form-fitting manner at least in sections, which has a profile which is continuous in the circumferential direction and has at least two projections extending axially in opposite directions. In this case, the connecting region 231, 241 is in each case provided with a fir-tree-shaped (cross-sectional) profile.

The two mutually remote end faces of a blade carrier 23 or 24 arranged stiffening rings 50 and 51 of a blade assembly 2a or 2b are each connected via a connecting device 6a or 6b and in the present case to each other and to the support portion 230 or 240 fixed. The respective connecting device 6a or 6b here comprises at least one separate connecting element in the form of a screw bolt 60. This screw bolt 60 is provided, inter alia, above the respective connecting region 231, 241 for the stiffening structure 5a or 5b. For axial fixing a nut 61 is turned on the bolt 60. In this case, the threaded bolt 60 extends above the respective connecting region 231, 241 inter alia by a connecting opening which is formed in an edge-side, radially projecting connecting web 50a or 50b of a stiffening ring 50 or 51, and by a connecting opening 233 or 243 in the carrier section 230 , 240.

Furthermore, a fixing of at least one connecting component 7a, 7b to a blade carrier 23, 24 is realized via a threaded bolt 60. Thus, the individual blade assemblies 2a, 2b and 2c via a plurality of sleeve-shaped connection components 7a, 7b rotatably connected to each other. The blade assemblies 2a and 2b according to the invention, each with a stiffening structure 5a, 5b are rotatably connected to each other via a first sleeve-shaped connecting component 7a, while the blade assembly 2b is non-rotatably connected to the rear blade assembly 2c via a further, second sleeve-shaped connecting component 7b. Each of the sleeve-shaped connecting components 7a, 7b has at its end faces an annular flange portion 70a, 70b. This flange portion 70a or 70b has in the circumferential direction a plurality of juxtaposed connection openings for fixing to the blade assemblies 2a, 2b and 2c.

In the present case, it is provided in the course of simpler installation and for additional weight reduction and increase in compactness that the connecting components 7a and 7b are additionally fixed to a blade assembly 2a or 2b via a connecting device 6a and 6b to the blade carriers 23 and 24, via which the stiffening rings 5a and 5b are fixed to each other and to the respective blade carrier 23 or 24. A single screw bolt 60 thus extends through connection openings of the flange sections 70a, 70b and the stiffening rings 50, 51 as well as through a connection opening 233 or 243 of the respective blade carrier 23 or 24.

As synonymous with the enlarged view of FIG. 2 4, the connecting ribs 50a and 50b of the stiffening rings 50 and 51 are sandwiched between the flange portions 70a and 70b. Between the connecting webs 50a and 50b, in turn, a part of the support portion of the respective blade carrier - in the FIG. 2 exemplarily the carrier 240 of the blade carrier 24 - sandwiched.

On the circumference, the stiffening rings 50 and 51 are fixed at several points via a respective connecting device 6a or 6b with at least one screw 60 at different, respectively ring segment or disk segment-shaped blade carriers 23, 24, wherein these stiffening rings 50, 51 via the same bolt 60 turn at least one sleeve-shaped connecting member 7a, 7b is fixed. This is particularly apparent from the front view of FIG. 3 illustrated schematically.

The in the FIG. 3 Exemplary and only schematically illustrated blade assembly 2b has along a circumferential direction about the central axis M a plurality of each ring segment-shaped or disk segment-shaped blade carrier 24 with at least one blade 21, in this case three blades 21, so that the individual blade carrier 24 define a circumferentially rotating blade row. The individual ring-segment-shaped or disk segment-shaped blade carrier 24 are in this case then stiffened over two stiffening rings 50 and 51 arranged on the different end faces and fixed relative to each other via the bolts 60 and also simultaneously connected to at least one connecting component 7a or 7b, via which in turn a non-rotatable Connection to another blade assembly 2a or 2c is realized.

As based on the FIGS. 4A and 4B is illustrated for different variants of the stiffening structures 5a, 5b, each stiffening ring 50, 51 of the respective stiffening structure 5a or 5b, a sheathed MMC core 500, for example, a TiMMC core. About the preparation of the stiffening rings 50 and 51 in MMC design, a significantly increased rigidity of the blade carrier 23 or 24 is achieved at a comparatively low weight. Here, a stiffening ring 50 or 51 extends with a Umgriffabschnitt 50.1 or 51.2 axially below one of the respective through hole O1 or O2 facing edge of the connecting portion 231 or 241 in the direction of the other end face. A radially inner edge of the respective blade carrier 23 or 24 is thus encompassed by each stiffening ring 50 or 51 at least partially L-shaped. This will in particular facilitates the radial securing of the respective reinforcing ring 50, 51 on the support portion 230 or 240 and is also a support of the blade carrier 23, 24 below the connecting portion 231, 241 reached.

In the present case, both stiffening rings 50 and 51, each with an encompassing section 50.1 or 51.2, extend axially below the inner edge of the carrier section 231 or 241 of the blade carrier 23 or 24 such that the stiffening rings 50 and 51 abut one another directly via their encompassing sections 50.1 and 51.2. The stiffening rings 50 and 51 provided on both sides of the connecting portion 231 or 241, which are each held in a form-fitting manner to the respective connecting portion 231 or 241, are thus immediately adjacent to each other and the stiffening structure 5a or 5b formed therewith extends completely through the through-hole O1 or O2.

By virtue of the stiffening structure 5a or 5b with the stiffening rings 50 and 51 arranged on the end faces of the blade carrier 23 or 24 facing away from one another, radially acting forces can be absorbed in particular. By circumferentially encircling profiling of the connecting portion 231 or 241 but at the same time a simpler installation and simple radial securing of the blade carrier 23 or 24 to be mounted stiffening rings 50 and 51 is given.

In a fir-tree-shaped cross-sectional profile corresponding to the variants of FIGS. 4A and 4B The connecting region 241 exemplarily illustrated here forms pairs of projections 2410.1 / 2410.2, 2411.1 / 2411.2 and 2412.1 / 2412.2 extending in opposite directions. Each of these axial projections 2410.1 to 2412.2 protrudes annularly on an end face of the support portion 240. To form the fir-tree-shaped profile, the axial length of the individual axial projections 2410.1 to 2412.1 or 2410.2 to 2412.2 per end face decreases in the radial direction, in the present case radially inwards. Accordingly, a pair of axial projections 2412.1 / 2412.2, which is closest to the through hole O2, the smallest axial extent and radially outwardly arranged pairs of axial projections 2411.1 / 2411.2 and 2410.1 / 2410.2 each axially further.

At the individual stiffening rings 50 and 51 are provided with the projections 2410.1 to 2412.1 or 2410.2 to 2412.2 one end side corresponding grooves, so that the respective mounted on an end side stiffening ring 50 or 51 each projection 2410.1 to 2412.1 or 2410.2 to 2412.2 at the respective end face positively embraces and consequently each projection 2410.1 to 2412.2 each between a radially further inner and radially further outside portion of the respective reinforcing ring 50 or 51 is added. By thus formed positive connection between the blade carrier 24 and the stiffening rings 50 and 51 radial loads occurring during operation of the engine T are distributed over the fir-tree-shaped profile in the stiffening structure 5a introduced. In addition, the stiffening structure 5a on the support section 240 of the blade carrier 24 is already radially fixed by attaching the stiffening rings 50, 51 without additional fastening means.

In the embodiment of the FIG. 4B It is further contemplated that the MMC core 500 of a stiffening ring 50 or 51 extends with at least a portion 500.1 or 500.2 of the metal matrix composite material below the inner edge of the support portion 240. Here, the MMC core in cross-section is substantially L-shaped. In the variant of FIG. 2A Thus, the MMC core 500 is only axially adjacent to the connection region 241 and in particular adjacent to the projections 2410.1 to 2412.2 arranged. In the variant of FIG. 2B In contrast, the MMC core 500 is arranged axially next to the connection region 241 and at least partially below the connection region 241 and consequently in particular adjacent to the projections 2410.1 to 2412.2 and at least partially below the projections 2410.1 to 2412.2.

With the FIGS. 5A and 5B Two different variants of the blade carrier 23, 24 of the blade assembly 2a or 2b are illustrated. In both variants, the blade carrier 23, 24 has a circumferentially extending fir-tree-shaped cross-sectional profile at the connection region 231 or 243 for the stiffening structure 5a or 5b and their stiffening rings 50 and 51 to be attached here. While in the variant of FIG. 5A the ring segment or disk segment-shaped blade carrier 23, 24 is formed with integrally formed thereon rotor blades 20, 21, the blade carrier 23, 24 of the FIG. 5B a plurality of circumferentially arranged side by side mounting grooves 232, 242 for thereto to be fixed blade roots 200, 210 of the blades 20, 21.

Based on the cross-sectional representation of FIG. 6 is further exemplified with regard to a fir-tree-shaped profile of the connecting portion 241 of a blade carrier 24, via which design parameters, if necessary, the connection between the blade carrier 24 and the stiffening rings 50, 51 and thus the force transmission can be influenced in the stiffening structure 5b.

For example, in the present case, a radius Ra is shown for a transition region between a radially extending end face of the carrier section 240 and a radially outermost projection 2410.1 of an end face, over the size of which the degree of concavity of the transitional area is influenced.

A geometry of the fir-tree-shaped profile can be further characterized by an angle α, the two tangents to each other, each of which are applied in a cross-sectional view along the central axis M to the ends of the axial projections 2410.1 to 2412.1 or 2410.2 to 2412.2 a front side. The greater the angle α, the greater the axial extent of the fir-tree-shaped profile and / or the greater the gradation in the axial extent between the projections 2410.1 to 2412.1 or 2410.2 to 2412.2 provided on one end face.

LIST OF REFERENCE NUMBERS

11

Low-pressure compressor

12

High-pressure compressors

13

High-pressure turbine

14

Intermediate pressure turbine

15

Low-pressure turbine

20, 21, 22

blade

200, 210, 220

blade

23, 24, 25

blade carrier

230, 240, 250

support section

231

connecting area

232, 242

mounting groove

233, 243

connecting opening

241

connecting area

2410.1, 2410.2, 2411.1, 2411.2, 2412.1, 2412.2

Axial projection

2a, 2b, 2c

Blade assembly

30, 31

vane

4.1, 4.2

flange

50, 51

Stiffening ring (stiffening element)

50.1, 51.2

Umgriffabschnitt

500

MMC core

500.1, 500.2,

MMC Section

50a, 50b

connecting web

5a, 5b

stiffening structure

60

bolts

61

mother

6a, 6b

connecting device

70a, 70b

flange

7a, 7b

Connecting component (sleeve / sleeve segment-shaped)

A

outlet

B

bypass channel

BK

combustor section

C

exit cone

e

Inlet / Intake

F

fan

FC

fan casing

M

Central axis / rotation axis

O1, O2

Through opening

R

entry direction

Ra

radius

S

rotor shaft

T

Turbofan engine (gas turbine engine)

TT

turbine

V

compressor

α

corner

Claims (15)

1. Rotor blade assembly group for an engine (T) with at least one blade carrier (23, 24), having multiple rotor blades (20, 21) that are provided with multiple further rotor blades (20, 21) along a circle line about a central axis (M) of the rotor blade assembly group (2a, 2b), wherein

   - the blade carrier (23, 24) has a carrier section (230, 240) that extends radially inwards in the direction of the central axis (M) with respect to the rotor blades (20, 21),

   - the carrier section (230, 240) comprises a connection area (231, 241) at which a stiffening structure (5a, 5b) with at least one first stiffening element (50) and at least one second stiffening element (51) is fixedly attached, and

   - the first stiffening element (50) is arranged at a first face side of the blade carrier (23, 24) and the second stiffening element (51) is arranged at a second face side that is facing away from the first face side, wherein the at least one first stiffening element (50) and the at least one second stiffening element (51) are connected to the connection area (231, 241) of the blade carrier (23, 24) and in addition are connected to each other,

   characterized in that
   the blade carrier (23, 24) is embodied in a ring-segment-shaped or disc-segment-shaped manner along the circle line.
2. Rotor blade assembly group according to claim 1, characterized in that the first and second stiffening elements (50, 51), which are arranged at different face sides of the blade carrier (23, 24), are connected to each other via at least one connection appliance (6a, 6b).
3. Rotor blade assembly group according to claim 2, characterized in that at least one separate connection element (60) of the connection appliance (6a, 6b) extends through a connection opening (243) in the carrier section (230, 240) to connect the first and second stiffening elements (50, 51) to each other.
4. Rotor blade assembly group according to claim 2 or 3, characterized in that the connection appliance (6a, 6b) is further configured and provided for connecting the rotor blade assembly group (2a, 2c) to the connection component (7a, 7b) by means of which the rotor blade assembly group (2a, 2b) is connected in a torque-proof manner to a further rotor blade assembly group (2b, 2a, 2c) that is arranged inside the engine (T) in an axially offset manner with respect to the central axis (M).
5. Rotor blade assembly group according to claims 3 and 4, characterized in that the at least one separate connection element (60) extends through a connection opening (243) in the carrier section (230, 240) as well as through a connection opening in the connection component (7a, 7b).
6. Rotor blade assembly group according to any of the preceding claims, characterized in that at least the first or the second stiffening element (50, 51) is formed in a ringshaped manner.
7. Rotor blade assembly group to any of the preceding claims, characterized in that at least one of the first and second stiffening elements (50, 51) is at least partially made of a metal matrix composite.
8. Rotor blade assembly group according to claim 7, characterized in that at least one of the first and second stiffening elements (50, 51) has an externally coated core (500) made of a metal matrix composite.
9. Rotor blade assembly group according to claim 7 or 8, characterized in that the rotor blade assembly group (2a, 2b) has a passage hole (O1, O2) that extends axially with respect to the central axis (M) and that is radially delimited by an inner edge of the carrier section (230, 240), and a section of the first or second stiffening element (50, 51) that is made of a metal matrix composite axially extends radially inside with respect to the inner edge of the connection area (231, 241).
10. Rotor blade assembly group according to any of the preceding claims, characterized in that the connection area (231, 241) forms at least one axial projection (2410.1-2412.2) around which a first or second stiffening element (50, 51) engages in a form-fit manner, so that the axial projection (2410.1-2412.2) is received at least partially between a radially outer and a radially inner section of this stiffening element (50, 51).
11. Rotor blade assembly group according to any of the preceding claims, characterized in that the rotor blade assembly group (2a, 2b) has a passage hole (O1, O2) that extends axially with respect to the central axis (M) and that is radially delimited by an inner edge of the carrier section (230, 240), and a first or second stiffening element (50, 51) of the stiffening structure (5a, 5b) axially extends radially inside with respect to the inner edge of the connection area (231, 241) with at least one section (50.1, 51.2).
12. Rotor blade assembly group for an engine (T), in particular according to any of the claims 1 to 11, with at least one blade carrier (23, 24) that has multiple rotor blades (20, 21) that are provided with multiple further rotor blades (20, 21) along a circle line about a central axis (M) of the rotor blade assembly group (2a, 2b), wherein

    - the blade carrier (23, 24) has a carrier section (230, 240) that extends radially inwards in the direction of the central axis (M) with respect to the rotor blades (20, 21),

    - the carrier section (230, 240) comprises a connection area (231, 241) at which a stiffening structure (5a, 5b) with at least one stiffening element (50, 51) is fixedly attached, and

    - the stiffening element (50, 51) is arranged at a first or second face side of the blade carrier (23, 24),

    characterized in that
    the blade carrier (23, 24) is formed in a ring-segment-shaped or disc-segment-shaped manner along the circle line, and

    (a) the connection area (231, 241) forms at least one axial projection (2410.1-2412.2) around which the at least one stiffening element (50, 51) engages in a form-fit manner, so that the axial projection (2410.1-2412.2) is received at least partially between a radially outer and a radially inner section of the stiffening element (50, 51),
    and/or

    (b) the rotor blade assembly group (2a, 2b) has a passage hole (O1, O2) that extends axially with respect to the central axis (M) and that is radially delimited by an inner edge of the carrier section (230, 240), and the at least one stiffening element (50, 51) of the stiffening structure (5a, 5b) extends radially inside with respect to the inner edge of the connection area (231, 241) with at least one section (50.1, 51.2).
13. Rotor blade assembly group according to claim 10 or 12, characterized in that the axial projection (2410.1-2412.2) is part of a profile of the connection area (231, 241) that has a T-shaped, I-shaped or firtree-shaped cross section.
14. Rotor blade assembly group according to claim 13, characterized in that the profile of the connection area (231, 241) that has a T-shaped, I-shaped or firtree-shaped cross section extends along a circle line about the central axis (M) at least in certain sections.
15. Gas turbine engine with at least one rotor blade assembly group (2a, 2b) according to any of the claims 1 to 14.

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