EP3287608A1 - Internal ring for a guide- blade rim of a turbomachine - Google Patents

Abstract

The invention relates to an inner ring (14) for a vane ring (10) of a turbomachine, by means of which adjustable guide vanes (12) are rotatably mounted, wherein the inner ring (14) comprises a first and a second fixing ring (16a, 16b), which over at least a fixing element (18) which is axial relative to a central axis (M) of the inner ring (14), wherein the at least one fixing element (18) has a blade bearing (20) which projects radially with respect to the central axis (M) and has an associated guide blade (12) ) for rotatably supporting the vane (12). The invention further relates to a method for producing a vane ring (10) of a turbomachine using such an inner ring (14).

Description

The invention relates to an inner ring for a vane ring of a turbomachine, a method for producing a vane ring of a turbomachine and a turbomachine with at least one such inner ring and / or vane ring.

Multi-stage turbomachines, such as thermal gas turbines often include a vane ring between adjacent rotor stages. These vane rings are at least partially equipped with adjustable guide vanes in order to deflect the respective operating fluid of the turbomachine in a targeted manner, so that the operating fluid impinges on the downstream rotor stage at an optimum angle. The adjustable vanes are rotatably mounted at one end in an outer ring or housing of the turbomachine and the other end in an inner ring.

From the DE 10 2005 042 747 a gas turbine is known, which comprises a stator vane ring with an inner ring as a stator stage in a compressor, wherein the inner ring consists of elastically deformable semicircular ring segments. For mounting the inner ring of this deformed until radially inner bearing pin of the vanes can be arranged in corresponding bushings of the inner ring. After relaxing the inner ring of this is connected to a carrier.

A disadvantage of the known inner ring or on a vane ring provided with this is the fact that the inner ring due to its elastic deformability at a given axial length has a comparatively low mechanical stability and aerodynamic load capacity, which it during operation of the associated turbomachine Flow losses and an associated deterioration of the efficiency, the surge limit and the performance of the turbomachine can come.

Object of the present invention is to provide an inner ring for a vane ring of a turbomachine, which has a higher mechanical and aerodynamic load capacity has. Further objects of the invention are to provide a method for producing a guide vane ring with a higher mechanical and aerodynamic load capacity as well as a correspondingly improved turbomachine.

The objects are achieved by an inner ring with the features of claim 1, a method according to claim 11 and by a turbomachine according to claim 15. Advantageous embodiments with expedient developments of the invention are specified in the respective subclaims, wherein advantageous embodiments of each invention aspect are to be regarded as advantageous embodiments of the other aspects of the invention and vice versa.

A first aspect of the invention relates to an inner ring for a vane ring of a turbomachine, by means of which adjustable guide vanes are rotatably storable. A higher mechanical and aerodynamic load capacity of the inner ring and thus the vane ring is inventively achieved in that the inner ring comprises a first and a second fixing ring, which are connected to each other via at least one relative to a central axis of the inner ring fixing element, wherein the at least one fixing element with a an associated guide vane corresponding, with respect to the central axis radially projecting blade storage for rotatably supporting the vane includes. In other words, the inner ring according to the invention comprises two fixing rings, which are connected to each other via one or more axially arranged fixing elements, wherein each fixing additionally comprises a radially projecting or projecting blade bearing and thus both the functionality of the axial fixation and the pivotal mounting of an associated guide vane united. Due to the division of the inner ring into two fixing rings, it is also not necessary to form the fixing rings elastically deformable for mounting, since the fixing rings can be arranged without deformation of an upstream and downstream side of the guide vanes and can be combined via the at least one fixing element to the inner ring , Due to the higher mechanical and aerodynamic load capacity of the inner ring an improvement in the efficiency, the surge limit and the power of an associated turbomachine is made possible with the same axial length of the associated stator stage or the associated vane ring. By integrating these two functionalities in the fixing element also space is gained because no additional space is required for through-bolts or other securing means. Thereby, the pitch, that is, the circumferential distance between the vanes can be reduced, whereby additional aerodynamic advantages are achieved. Alternatively, it is possible to reduce the axial length of the provided with the inner ring stator stage or provided with the inner ring vane ring with the same mechanical and aerodynamic load capacity compared to the prior art. Preferably, the inner ring for such a guide vane comprises such a fixing element. In the context of the present invention, terms such as "axial" and "radial" basically refer to the central axis of the inner ring, which in the installed position runs coaxially to a rotational axis of an associated turbomachine. The fixing rings can basically be produced by means of turning and / or milling methods or generatively, for example by selective laser melting. The fixing element (s) may also generally be produced generatively, for example by selective laser melting. Alternatively, however, other production methods, such as forging and / or milling are conceivable.

In an advantageous embodiment of the invention, it is provided that the fixing element comprises a bushing as a blade bearing, in which a bearing journal of the associated vane can be arranged, or that the fixing element as a blade bearing comprises a bearing pin, which can be arranged in a socket of the associated vane. As a result, the fixing element can be optimally adapted to the respective design of the associated guide vane as the opposite.

In a further advantageous embodiment of the invention, it is provided that the first fixing ring and / or the second fixing ring is formed segmented or are. For example, the first fixing ring and / or the second fixing ring may be divided into two, three, four or more ring segments. This segmentation facilitates in certain applications, the assembly of the respective fixing ring and thus the vane ring.

Further advantages result if the first fixing ring and / or the second fixing ring carries or carry a sealing element, in particular a honeycomb seal. As a result, the inner ring can be sealed against other components of the turbomachine, which contributes to a further reduction of flow losses. The sealing element can be materially connected, for example by soldering, with the relevant fixing ring. Alternatively, the relevant Fixing ring be produced generatively together with the sealing element. However, other manufacturing methods are conceivable.

In a further advantageous embodiment of the invention, it is provided that the fixing element against rotation, in particular form-fitting, is arranged in a corresponding, preferably polygonal mounting opening of the first fixing ring and / or the second fixing ring. In other words, it is provided that the fixing element along its axial extent has one or more areas which are geometrically designed such that the fixing element is arranged against rotation in an associated mounting opening. For example, the relevant area of the fixing element and the associated mounting opening in cross section may be oval, triangular, square, rectangular or polygonal, whereby a fluid-tight and torsion-proof arrangement is ensured. In addition, tilting of a guide blade mounted by means of the fixing element is particularly reliably prevented in this way. The mounting opening (s) can be introduced, for example, by drilling, milling and / or electrochemical removal (ECM / PEM) in the respective fixing ring. If both fixing rings should have mutually aligned mounting holes, it has been shown to minimize tolerance to be advantageous to pair the fixing rings analogous to the installation position and to produce the mounting holes together.

Further advantages arise when the fixing element is coupled in a first end region with a locking element designed as a locking element. As a result, the fixing element can be supported axially on one of the fixing rings and is secured at least in one direction against falling out.

Furthermore, it has proved to be advantageous if the blocking plate is U-shaped and / or arranged in a groove of the fixing element. As a result, the locking plate can be easily pushed onto the fixing for mounting.

In a further advantageous embodiment of the invention, it is provided that the first fixing ring and / or the second fixing ring has a receiving profile in which the locking plate is added safe fall. The receiving profile can in principle also be formed by the first and second fixing ring, if they are arranged in their installation position, so that each fixing ring taken by itself has only a portion of the receiving profile. Alternatively or additionally, it is provided that the blocking plate rests on the second fixing ring. As a result, an undesired falling out of the locking plate in the radial direction during operation of an associated turbomachine is impossible.

Further advantages result from the fact that the fixing element is fixed in a second end region with a securing element, preferably designed as a nut, on the second fixing ring. In this way, the fixing element can be axially supported on the respective fixing ring and is secured at least in one direction against falling out. If a nut is used as the securing element, the fixing element preferably has a corresponding thread.

Further advantages result if the blade bearing of the fixing element is sealed by means of a sealing element, in particular a sealing ring, relative to the first fixing ring and / or the second fixing ring. As a result, the flow through the fixing rings is additionally reduced.

A second aspect of the invention relates to a method for producing a vane ring of a turbomachine. In this case, at least the steps a) providing an outer ring and a plurality of adjustable guide vanes, b) inserting radially outer blade bearings of the guide vanes in the outer ring, c) connecting radially inner blade bearings of the guide vanes, each with a radially projecting blade bearing an associated fixing element, d) arranging e) arranging a respective securing element on first end regions of the fixing elements, the securing elements limiting a relative axial movement of the first fixing ring relative to the fixing elements, f) arranging a second fixing ring on respective second end regions of the fixing elements, such that the fixing elements extend axially between the first and second fixing ring and g) arranging in each case a securing element on each second end region of the fixing elements, wherein the securing elements have a relative axial B Limit ewegung the second fixing ring relative to the fixing, performed. By using the formed according to the first aspect of the invention inner ring for the production of the vane ring this has a certain axial length one comparatively higher mechanical and aerodynamic load capacity than known from the prior art vane rings. The outer ring can in principle be formed in one piece or as part of the housing. The skilled worker is aware that the specified sequence of steps can be varied at least in part, without departing from the scope of the inventive method. Furthermore, it can be provided that the specified steps for disassembly of the vane ring can be carried out in the reverse order. Also in this case, corresponding variations of the step sequence are conceivable.

In an advantageous embodiment of the invention in step c) bushes are used as radially inner blade bearings in the inner plate of the vanes and used bearing pins as radially projecting blade bearings of the fixing in the jacks. Alternatively or additionally, in step c) bearing journals are used as blade bearings of the guide vanes in respective bushes as radially projecting blade bearings of the fixing elements. In this way, the rotatable mounting of the guide vanes on the fixing elements in dependence on the specific configuration of the guide vanes and the existing space can be done.

Further advantages are obtained if in step e) each formed as a locking plate securing element is inserted radially from the inside into a respective groove in the first end portions of the fixing and rests after placing the second fixing ring in step f) on this. As a result, the fuse element is reliably protected against falling out.

A mechanically particularly stable connection of the inner ring is made possible in a further advantageous embodiment of the invention in that in step g) nuts are screwed as securing elements on the second end portions of the fixing elements until the first and the second fixing ring are fixed on the fixing elements to each other.

A third aspect of the invention relates to a turbomachine, in particular an aircraft engine, comprising at least one inner ring according to the first aspect of the invention and / or at least one vane ring, which is produced by a method according to the second aspect of the invention. The resulting features and their advantages can be found in the descriptions of the first and second aspects of the invention.

Fig. 1

eine schematische seitliche Schnittansicht eines erfindungsgemäßen Innenrings für einen Leitschaufelkranz gemäß einem ersten Ausführungsbeispiel;

Fig. 2

eine ausschnittsweise Perspektivansicht des Leitschaufelkranzes in Strömungsrichtung;

Fig. 3

eine schematische Schnittansicht des Leitschaufelkranzes;

Fig. 4

eine schematische seitliche Schnittansicht eines erfindungsgemäßen Innenrings für einen Leitschaufelkranz gemäß einem zweiten Ausführungsbeispiel;

Fig. 5

eine schematische Perspektivansicht eines in Fig. 4 gezeigten Fixierelements; und

Fig. 6

eine schematische Perspektivansicht des Fixierelements, das in einem Fixierring angeordnet ist.

Further features of the invention will become apparent from the claims, the figures and the description of the figures. The features and feature combinations mentioned above in the description, as well as the features and feature combinations mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respectively specified combination but also in other combinations without the scope of the invention leave. Thus, embodiments of the invention are to be regarded as encompassed and disclosed, which are not explicitly shown and explained in the figures, however, emerge and can be produced by separated combinations of features from the embodiments explained. Embodiments and combinations of features are also to be regarded as disclosed, which thus do not have all the features of an originally formulated independent claim. Showing:

Fig. 1

a schematic sectional side view of an inner ring according to the invention for a vane ring according to a first embodiment;

Fig. 2

a fragmentary perspective view of the vane ring in the flow direction;

Fig. 3

a schematic sectional view of the vane ring;

Fig. 4

a schematic sectional side view of an inner ring according to the invention for a vane ring according to a second embodiment;

Fig. 5

a schematic perspective view of an in Fig. 4 shown fixing element; and

Fig. 6

a schematic perspective view of the fixing element, which is arranged in a fixing ring.

Fig. 1 shows a schematic sectional side view of an inner ring 14 according to the invention for a vane ring 10 according to a first embodiment, wherein only the radially inner region is shown. Fig. 1 is described below in synopsis with Fig. 2 and Fig. 3 be explained, wherein Fig. 2 a fragmentary perspective view of the vane ring 10 in the flow direction according to arrow II and Fig. 3 a schematic sectional view of the Guide vane 10 according to section line III-III shows. The vane ring 10 comprises a plurality of adjustable guide vanes 12, which are rotatably mounted in an inner ring 14, wherein the inner ring 14 is an independent invention aspect. The inner ring 14 comprises a first fixing ring 16a which is axially forward when viewed in the flow direction, and an axially rear second fixing ring 16b, between which a fixing element 18 extends axially per guide blade 12 relative to a central axis M of the inner ring 14. The fixing rings 16a, 16b can be formed independently of one another as a 360 ° or ring elements or segmented, for example as half-ring segments. The axially rear fixing ring 16b additionally carries a sealing element 17, which in the present case is designed as a honeycomb seal and is connected by soldering to the fixing ring 16b. The fixing element 18 comprises approximately in its center a radially outwardly projecting blade bearing 20, which is in the present case designed as a bearing journal. It is clear that the fixing rings 16a, 16b in the mounted state form an opening 22 through which the blade bearing 20 protrudes. The guide vane 12 in turn comprises as a blade bearing a bushing 24 which is arranged in a bore in the region of the inner plate 26 and in which the bearing pin 20 of the fixing element 18 is inserted.

The fixing element 18 has a first region 18a and a second region 18b, which are square or square in cross section. In these areas 18a, 18b, the fixing element 18 is positively and non-rotatably arranged in corresponding mounting holes 28a, 28b in the first and second fixing ring 16a, 16b. As a result, the guide vane 12 is additionally secured in its installed position against tilting.

For axial positioning and mutual fixing of the fixing element 18 and the fixing rings 16a, 16b, a securing element 30a designed as a U-shaped blocking plate is pushed onto a first end region of the fixing element 18. It can be seen that the securing element 30a rests on the second fixing ring 16b and is received in a corresponding receiving profile 32. This reliably prevents unwanted falling out of the securing element 30a. At its opposite end region, the fixing element 18 is screwed to a securing element 30b designed as a nut, whereby the fixing rings 16a, 16b are connected to one another via the fixing element 18.

To mount the vane ring 10, the radially outer ends of the guide vanes 12 are inserted into a one-piece outer ring (not shown) or in a housing of a turbomachine. Subsequently, in each case a bushing 24 and a fixing element 18 are inserted into the inner plates 26 of the individual guide vanes 12. Thereafter, the first fixing ring 16a is pushed from the front onto the fixing elements 18 and the securing elements 30a are pushed radially from below onto the fixing elements 18. Then the second fixing ring 16b is pushed from the rear side onto the fixing elements 18, whereby at the same time the securing elements 30a are secured against radial falling out. Finally, the nuts 30b are screwed onto the fixing elements 18.

Fig. 4 shows a schematic sectional side view of an inner ring 14 according to the invention for a vane ring 10 according to a second embodiment. The basic structure and the assembly or disassembly of the vane ring 10 substantially correspond to those of the first embodiment. In contrast to the first embodiment, the fixing element 18 in the present case as a blade bearing 20 on a socket or bore, in which a bearing pin 34 of the associated vane 12 is arranged. Furthermore, the blade bearing 20 of the fixing element 18 is sealed by means of a sealing element 36 designed as a sealing ring or piston ring relative to the first fixing ring 16a and the second fixing ring 16b. During assembly, the sealing element 36 is arranged on the outside of the blade bearing 20 before the arrangement of the fixing rings 16a, 16b.

Fig. 5 shows for further clarification a schematic perspective view of the in Fig. 4 shown fixing element 18, in the blade bearing 20, the guide vane 12 is arranged. It can be seen that the blocking plate 30a is inserted into a groove 38 in an end region of the fixing element 18. Likewise, the square-shaped areas 18a, 18b can be seen, which serve for the positive and rotationally fixed arrangement of the fixing element 18.

Fig. 6 shows a schematic perspective view of the fixing element 18, which is arranged in the mounting hole 28b of the axially rear fixing ring 16b. One recognizes the square shape of the mounting openings 28b corresponding to the area 18b of the individual fixing elements. Likewise, the groove 38 of the fixing element can be seen.

LIST OF REFERENCE NUMBERS

10

vane ring

12

vane

14

inner ring

16a

first fixation ring

16b

second fixing ring

17

sealing element

18

fixing

18a

Area

18b

Area

20

shovel storage

22

opening

24

Rifle

26

inside plate

28a

mounting holes

28b

mounting hole

30a

fuse element

30b

fuse element

32

Up profile

34

pivot

36

sealing element

38

groove

M

central axis

Claims (15)

Inner ring (14) for a guide vane ring (10) of a turbomachine, by means of which adjustable guide vanes (12) are rotatably storable,
characterized in that
this comprises a first and a second fixing ring (16a, 16b) which are connected to one another via at least one fixing element (18) which is axial relative to a central axis (M) of the inner ring (14), wherein the at least one fixing element (18) is associated with one Guide vane (12) corresponding, with respect to the central axis (M) radially projecting blade bearing (20) for rotatably supporting the vane (12). Inner ring (14) according to claim 1,
characterized in that
the fixing element (18) as a blade bearing (20) comprises a bushing, in which a bearing journal (34) of the associated guide blade (12) can be arranged, or in that the fixing element (18) as a blade bearing (20) comprises a bearing journal, which in a socket (24) of the associated guide vane (12) can be arranged. Inner ring (14) according to claim 1 or 2,
characterized in that
the first fixing ring (16a) and / or the second fixing ring (16b) is or are segmented. Inner ring (14) according to one of claims 1 to 3,
characterized in that
the first fixing ring (16a) and / or the second fixing ring (16b) bears or carries a sealing element (17), in particular a honeycomb seal. Inner ring (14) according to one of claims 1 to 4,
characterized in that
the fixing element (18) against rotation, in particular form-fitting, in a corresponding, preferably polygonal mounting opening (28a, 28b) of the first fixing ring (16a) and / or the second fixing ring (16b) is arranged. Inner ring (14) according to one of claims 1 to 5,
characterized in that
the fixing element (18) is coupled in a first end region with a securing element (30a) designed as a blocking plate. Inner ring (14) according to claim 6,
characterized in that
the blocking plate is U-shaped and / or arranged in a groove (38) of the fixing element (18). Inner ring (14) according to claim 6 or 7,
characterized in that
the first fixing ring (16a) and / or the second fixing ring (16b) has a receiving profile (32) in which the locking plate is received safe fall and / or that the locking plate rests on the second fixing ring (16b). Inner ring (14) according to one of claims 1 to 8,
characterized in that
the fixing element (18) is fixed to the second fixing ring (16b) in a second end region with a securing element (30b) which is preferably designed as a nut. Inner ring (14) according to one of claims 1 to 9,
characterized in that
the blade bearing (20) of the fixing element (18) by means of a sealing element (36), in particular a sealing ring, relative to the first fixing ring (16a) and / or the second fixing ring (16b) is sealed. Method for producing a vane ring (10) of a turbomachine, comprising the steps: a) providing an outer ring and a plurality of adjustable guide vanes (12); b) inserting radially outer blade bearings of the guide vanes (12) in the outer ring; c) connecting radially inner blade bearings of the guide vanes (12) each having a radially projecting blade bearing (20) of an associated fixing element (18); d) arranging a first fixing ring (16a) on respective first end portions of the fixing elements (18); e) arranging in each case a securing element (30a) at first end regions of the fixing elements (18), wherein the securing elements (30a) limit a relative axial movement of the first fixing ring (16a) with respect to the fixing elements (18); f) disposing a second fixing ring (16b) on respective second end portions of the fixing members (18) so that the fixing members (18) extend axially between the first and second fixing rings (16a, 16b); and g) arranging in each case a securing element (30b) on each second end region of the fixing elements (18), wherein the securing elements (30b) delimit a relative axial movement of the second fixing ring (16b) relative to the fixing elements (18). Method according to claim 11,
characterized in that
in step c) bushings (24) are used as radially inner blade bearings in inner plates (26) of the guide vanes (12) and bearing pins are used as radially projecting blade bearings (20) of the fixing elements (18) in the bushes (24) and / or in Step c) bearing journals (34) are used as blade bearings of the guide vanes (12) in respective bushes as radially projecting blade bearings (20) of the fixing elements (18). Method according to claim 11 or 12,
characterized in that
in step e), in each case a securing element (30a) designed as a blocking plate is inserted radially from the inside into a respective groove (38) in the first end regions of the fixing elements (18) and after arranging the second fixing ring (16b) in step f) on this rests. Method according to one of claims 11 to 13,
characterized in that
in step g) nuts are screwed as securing elements (30b) on the second end portions of the fixing elements (18) until the first and the second fixing ring (16a, 16b) via the fixing elements (18) are fixed to each other. Turbomachine, in particular an aircraft engine, comprising at least one inner ring (14) according to one of claims 1 to 10 and / or at least one vane ring (10), which is produced by a method according to one of claims 11 to 14.

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