EP2696038A1 - Guide vane row for a turbomachine - Google Patents

Abstract

The guide vane ring (1) has several rotatable guide vanes (2) with an inner ring (4) for radial inner stabilization of the guide vanes having a seal carrier (6). The seal carrier is arranged radially and inwardly with respect to the inner ring. A spring-like sealing element (58) with an annular C-shaped section, is arranged between an inner ring portion and a seal support portion, so that the inner ring and the seal carrier are clamped to each other. An independent claim is included for turbomachine.

Description

The invention relates to a guide vane ring according to the preamble of patent claim 1 and a turbomachine.

Turbomachines such as aircraft engines and stationary gas turbines regularly have at least one compressor-side adjustable guide vane row with a large number of guide vanes which can be pivoted about their main axis or vane axis in order to set optimum operating conditions. The adjustable or variable guide vane row forms a guide vane ring with an inner ring surrounding a rotor section. The inner ring serves for internal stabilization and storage of the guide vanes. He can, as in the EP 0 947 668 B1 shown, a plurality of radial bearing bores for receiving a respective blade-side journal. The inner ring consists of several ring segments, which are interconnected via a radially inner seal carrier. The seal carrier consists of semicircular carrier segments which are pushed onto the ring segments during assembly in the circumferential direction. For sealing a radial gap to the rotor portion of the seal carrier is provided on its side facing away from the vanes inner peripheral surface with a plurality of inlet linings, run into the rotor-side sealing fins or sealing tips. To ensure the ability to mount and for reasons of manufacturability, a mounting clearance is provided between the inner ring and the seal carrier. The mounting clearance creates paths for leakage flows between the inner ring and the seal carrier, which leads to a reduction of the compressor efficiency. On the other hand, the assembly play between the inner ring and the seal carrier during operation can lead to an inconvenient, operating point-dependent positioning of the inlet linings relative to the rotor section. Consequences are locally deeper inlets of the sealing fins in the inlet linings and an uneven radial gap, which also leads to an increase in leakage flows and thus to a deterioration of the compressor efficiency.

The object of the invention is to provide a guide vane ring for a turbomachine, eliminates the aforementioned disadvantages and allows both a sealing of leakage paths between an inner ring and a seal carrier and a defined positional fixation of the seal carrier on the inner ring. In addition, it is an object of the invention to provide a turbomachine, which has at least a high compressor efficiency.

This object is achieved by a guide vane ring with the features of patent claim 1 and by a turbomachine having the features of patent claim 10.

An inventive vane ring for a turbomachine has a plurality of rotatable vanes, an inner ring for radially inner stabilization of the guide vanes and a seal carrier. The seal carrier is arranged radially inwardly to the inner ring and held in a form-fitting manner. According to the invention, at least one spring-like sealing element is arranged between an inner ring section and a seal carrier section, by means of which the inner ring is clamped to the seal carrier.

On the one hand leakage paths between the inner ring and the seal carrier are sealed by the sealing element. Due to the spring action of the sealing element an assembly clearance between the inner ring and the seal carrier is eliminated and thus achieves a defined positional fixation of the seal carrier on the inner ring. A concentric positioning of the inlet linings carried by the seal carrier to the opposite rotor section is achieved at each operating point. As a result, the rotor-side sealing tips can run evenly into the inlet linings and a radial gap to the opposite rotor section is evenly sealed.

In one embodiment, the at least one sealing element braces the inner ring and the seal carrier in the radial direction with respect to a vane ring axis or a machine axis of the turbomachine with each other or against each other. The radial clamping ensures that the seal carrier is concentrically aligned with the inner ring and the rotor section, since it is acted upon circumferentially radially from outside to inside with a constant clamping force.

In another embodiment, the at least one sealing element braces the inner ring and the seal carrier in the axial direction with each other or against each other. This ensures in particular that the seal carrier is arranged in an axial nominal position on the inner ring and its inlet linings thus lie in their axial nominal position to the rotor section. Of course, the seal carrier and the inner ring can also be clamped simultaneously in the axial and in the radial direction.

The at least one sealing element is preferably arranged in a sealing element space, which is delimited by a side surface of the inner ring section and by at least one opposite counter surface of the seal carrier section. Depending on whether a clamping of the inner ring and the seal carrier in the radial direction or in the axial direction is intended, the side surface and the counter surface are opposite in the radial direction or in the axial direction. From a mounting perspective, it is favorable if the sealing element space is opened on one side in the axial direction, so that the sealing element can be inserted into the sealing element space after the sealing carrier has been pushed onto the inner ring.

However, the sealing element space can also be fully, i. be closed in the axial and in the radial direction. This prevents that the sealing element or parts of the sealing element can be sucked from the sealing element space in the turbomachine / can. "Closed" means that the sealing element space is designed such that the sealing element or parts of the sealing element can not be sucked out of the sealing element space. "Closed" does not mean that the sealing element space without the spring-like sealing element is gas-tight.

Regardless of whether the sealing element space is circumferentially open or closed, it is preferred if the sealing element space is arranged downstream of the guide vanes. With such positioning, the outer dimensions of the inner ring and the seal carrier can remain unchanged. Thus, the inner ring of the invention and the seal carrier according to the invention can be subsequently integrated as replacement parts in a conventional vane ring or exchanged for its conventional inner ring and seal carrier.

An exemplary sealing element has an annular C-profile. Such a profile is easy to manufacture, robust and allows a reliable seal and tension.

An alternative exemplary sealing element has an annular V-profile. Such a profile is easy to manufacture and easy to insert into the sealing element space in the circumferential direction due to the almost line-like contact with the side surface and the counter surface.

Another exemplary sealing element has an annular W-profile. Such a profile allows a large-scale contact with the respective side surface and the respective mating surface and thus has a large sealing surface.

The respective sealing element may be formed as a one-piece ring profile or consist of a plurality of ring segments, which are inserted side by side in the sealing element space and form a closed ring.

A turbomachine according to the invention has at least one guide vane ring according to the invention. Due to the sealed leakage paths between the inner ring and the seal carrier and the reduced radial gap losses between the inlet liners and the sealing fins, such a turbomachine is characterized by a higher compressor efficiency than a turbomachine with a conventional vane ring.

Other advantageous embodiments of the invention are the subject of further subclaims.

Figur 1

einen Axialschnitt durch einen erfindungsgemäßen Leitschaufelkranz im Bereich eines federartigen C-förmigen Dichtelements bei radialer Verspannung,

Figur 2

einen Axialschnitt durch einen erfindungsgemäßen Leitschaufelkranz im Bereich eines federartigen C-förmigen Dichtelements bei axialer Verspannung,

Figur 3

ein beispielhaftes federartiges V-förmiges Dichtelement, und

Figur 4

ein beispielhaftes federartiges W-förmiges Dichtelement.

In the following, preferred embodiments of the invention will be explained in more detail with reference to highly simplified schematic illustrations. Show it:

FIG. 1

an axial section through a guide vane ring according to the invention in the region of a spring-like C-shaped sealing element with radial clamping,

FIG. 2

an axial section through a vane ring according to the invention in the area a spring-like C-shaped sealing element with axial clamping,

FIG. 3

an exemplary spring-like V-shaped sealing element, and

FIG. 4

an exemplary spring-like W-shaped sealing element.

According to FIG. 1 an inventive vane ring 1 a turbomachine such as an aircraft engine at least a plurality of vanes 2, an inner ring 4 and a seal carrier 6. The vane ring 1 is arranged on the stator side in the compressor of the turbomachine and surrounds a rotor portion of a rotor, not shown, which is in the flow direction x of a main flow extending machine axis M rotates.

The guide vanes 2 are adjustable about their main axis H extending radially to the machine axis M and each have an airfoil 8, an inner blade plate 10 and a bearing journal 12 extending radially inwardly from the blade plate 10. In addition, the vanes 2 each have an outer, not shown Bucket plate and a radially outwardly extending from the outer blade plate adjusting pin, which cooperates with a housing-side adjusting device.

The inner blade plates 10 are each arranged in a radially outer countersunk portion 14 of the inner ring 4 radially passing through bearing bore 18. They have a radially inner and extending along the machine axis M underside 20 and an opposite bottom 20 opposite top 22. The top 22 is arranged obliquely to the machine axis M, wherein it extends radially in the flow direction x from inside to outside. It forms with a penetrated by the bearing bore 18 inner ring surface 24 a stepless or nearly stepless radially inner side wall portion of a flowed through by the main flow annulus.

The inner ring 4 serves for the radially inner stabilization or support of the guide vanes 2. It has the bearing bores 18 and the inner ring surface 24 and is spaced from the rotor section via a radial gap. It consists of two half-rings, each with an arc section of 180 °, in the region of a horizontal housing separation plane of the turbomachine are assembled to the inner ring 4. Of course, a stronger segmentation of the inner ring 4, for example in four ring segments possible.

The bearing bores 18 pass through the inner ring 4 in the radial direction. They have a bushing portion 26 for receiving bearing bushes 28 and the opposite to the bushing portion 26 radially enlarged countersinking portion 14 for receiving the inner blade plate 10th

The bushings 28 are inserted radially from the inside to the outside in the socket sections 26. They have a T-shaped cross section, each having a bearing portion 30 and a relative to the bearing portion 30 radially widened collar 32, by means of which they bear against a respective radially inner shoulder surface 34 of the half rings.

The guide vanes 2 dive with their bearing pins 12 in the bearing bushes 28 and are thus rotatably guided relative to its main axis H in the radial direction. In addition, a sliding disk 36 can be pushed onto the journal 12, which is arranged in the assembled state between the bushings 28 and the inner shrouds 10 and define a sliding surface for the guide vanes 2. The sliding disks 36 each form, in cooperation with the inner cover tape 10 and the collar 32, an axial guide of the rotor blades 2 relative to the main axis H.

The inner ring surface 24 extends downstream of the bearing bores 18 via a rear and obliquely to the machine axis M radially from inside to outside employed axial projection 38 of the inner ring 4. Between the axial projection 38 and the blades 8 is formed in each case a radial so-called flag gap 42, to achieve a high efficiency of the turbomachine and a high surge limit is minimized. To set the flag gap 42, at least some of the guide vanes 2 are mechanically coupled to the inner ring 4 or the half-ring in the radial direction. The mechanical coupling can be done for example by means of axial locking pins that pass through the inner ring 4 at least on one side and engage in a corresponding annular groove of the bearing pin 12.

For receiving the seal carrier 6, the inner ring 4 has a front end-side annular recess 44 and a rear axial annular projection 46, which are arranged radially inwardly of the inner ring surface 24.

The seal carrier 6 is used for positioning of inlet linings 48,50 for sealing the radial gap between the rotor and the inner ring 4. It is radially inwardly disposed on the inner ring 4 in a form-fitting manner. It preferably has two semicircular carrier segments, which are pushed in the circumferential direction on the ring segments. A carrier segment in each case consists of a base body 52, on whose inner circumferential surfaces the inlet linings 48, 50 are mounted for engagement of rotor-side sealing tips or sealing fins. The inlet linings 48, 50 are honeycomb seals, for example.

For fixing the seal carrier 6 on the inner ring 4, the base body 52 each have a front hook projection 54 and a rear annular recess 56. With the hook projection 54 of the seal carrier 6 engages positively in the front annular recess 44 of the inner ring 4 a. The rear annular recess 56 serves to receive the rear annular projection 46 of the inner ring 4th

To ensure the mountability of the seal carrier 6 on the inner ring 4, the front annular recess 44 and the front hook projection 54 and the rear annular projection 46 and the rear annular recess 56 are coordinated such that between the inner ring 4 and the seal carrier 6 a mounting clearance is formed. The seal carrier 6 is thus movable in the axial direction x and in the radial direction z relative to the inner ring 4. To eliminate the assembly clearance after assembly and thus during operation of the turbomachine, the inner ring 4 and the seal carrier 6 according to the invention via a spring-like sealing element 58 against each other or clamped together. In addition, the spring-like sealing element 58 causes a sealing of leakage paths between the inner ring 4 and the seal carrier 6, which are formed due to the mounting clearance.

The sealing element 58 is arranged in a sealing element space 60 between a portion of the inner ring 4 and a portion of the seal carrier 6. It has, for example, a C-shaped profile. It consists of several arched profile segments that are assembled or in the circumferential direction of the vane ring 1 side by side form a closed ring. Preferably, the sealing element 58 consists of two profile segments, each spanning an arc of 180 °.

The sealing element space 60 extends in the circumferential direction of the inner ring 4 and of the seal carrier 6. It is an annular space and arranged downstream of the guide vanes 2. It has a square or rectangular cross section and is formed between the axial projection 38 and the rear annular projection 46. It is delimited by two side surfaces 62, 64 of the inner ring 4 and by two mating surfaces 66, 68 of the seal carrier 6, of which one each in the radial direction z (side surface 62, mating surface 68) and one in the axial direction x (side surface 64, mating surface 66). extends.

At the in FIG. 1 the embodiment shown, the sealing element 58 is clamped between the radially outer side surface 64 and the radially inner counter surface 66. As a result, the clamping force of the sealing element 58 in the radial direction z of the machine axis or a Leitschaufelkranzachse oriented, whereby the inner ring 4 and the seal carrier 6 in the radial direction z are braced against each other. At the same time the leakage paths between the inner ring 4 and the seal element carrier 6 are sealed by the abutment of the sealing element 58 on the radially outer side surface 64 and on the radially inner counter surface 66.

In the case of radial clamping, it is fundamentally possible to dispense with the axially rear mating surface 68 and to form the sealing element space 60 open in the axial direction x. As a result, the assembly of the sealing element 58 is substantially simplified since the sealing element 58 can be inserted axially into the sealing element space 60 from the rear, only after the respective seal carrier segment 6 has been pushed onto the respective half ring of the inner ring 4. However, in order to prevent the sealing element 58 from being sucked into the turbomachine, it is preferred if the sealing element space 60 is completely closed. "Closed" means that the sealing element space 60 is formed such that the sealing element 58 or parts of the sealing element can not be sucked out of the sealing element space 60 or can. "Closed" does not mean that the sealing element space 60 without the spring-like sealing element 58 is gas-tight.

As in the embodiment according to FIG. 2 As shown, the sealing element 58 can alternatively be clamped between the axially front side surface 62 and the axially rearward counter surface 68, whereby its clamping force acts in the axial direction x and the inner ring 4 and the seal carrier 6 are braced against each other in the axial direction x. At the same time the leakage paths between the inner ring 4 and the seal element carrier 6 are sealed by the abutment of the sealing element 58 on the axially front side surface 62 and on the axially rearward counter surface 68. The axial desired position of the seal carrier 6 to the inner ring 4 is preferably determined by the abutment of the front hook projection 54 on the recess bottom 70 of the front annular recess 44 (not shown).

In the FIGS. 3 and 4 exemplary alternative spring-type sealing elements 58 are shown. So has that in FIG. 3 shown sealing element 58 a ring-like V-shaped profile and the in FIG. 4 Sealing element shown a ring-like W-shaped profile. The respective sealing element 58 consists of a plurality of arcuate profile segments which, when assembled or in the circumferential direction of the guide vane ring 1, form a closed ring next to each other. Preferably, the respective sealing element 58 consists of two profile segments, each spanning an arc of 180 °. The arrangement of these sealing elements 58 in the sealing element space 60 can according to the C-shaped sealing element 58 after the Figures 1 and 2 be made such that the inner ring 4 and the seal carrier 6 are clamped either predominantly or exclusively in the axial direction x or primarily or exclusively in the radial direction z against each other. The sake of completeness are in the FIGS. 3 and 4 the side surfaces 62, 64 and the mating surfaces 66, 68 of the sealing element space 60 outlined.

Of course, the sealing elements 58 after the FIGS. 1 to 4 Also executable such that the inner ring 4 and the seal carrier 6 are braced against each other both in the axial direction x and in the radial direction z.

Disclosed is a guide vane ring for a turbomachine whose inner ring and seal carrier are mutually braced by means of a spring-like sealing element, and a turbomachine with such a vane ring.

LIST OF REFERENCE NUMBERS

1

vane ring

2

vanes

4

inner ring

6

seal carrier

8th

airfoil

10

inner shovel plate

12

pivot

14

lowering section

18

bearing bore

20

bottom

22

top

24

Inner ring surface

26

bushing section

28

bushings

30

bearing section

32

collar

34

shoulder surface

36

sliding disk

38

axial projection

42

flags gap

44

front ring recess

46

rear ring projection

48

run-in coating

50

run-in coating

52

body

54

front hook projection

56

rear ring recess

58

sealing element

60

Sealing elements Space

62

Side surface radially

64

Side surface axially

66

Counter surface radially

68

Counter surface axially

70

recess base

H

Major axis / blade axis

M

machine axis

x

Flow direction / axial direction

z

radial direction

Claims (10)

Guide vane ring (1) for a turbomachine, with a plurality of rotatable vanes (2), with an inner ring (4) for radially inner stabilization of the guide vanes (2) and with a seal carrier (6), wherein the seal carrier (6) radially inward to Inner ring (4) is arranged and held on this form-fitting, characterized in that between an inner ring portion and a seal support portion at least one spring-like sealing element (58) is arranged, by means of which the inner ring (4) with the seal carrier (6) is clamped. Guide vane ring (1) according to claim 1, wherein the at least one sealing element (58) the inner ring and the seal carrier in the radial direction (z) clamped together. Guide vane ring (1) according to claim 1, wherein the at least one sealing element (58) the inner ring (4) and the seal carrier (6) in the axial direction (x) clamped together. The vane ring (1) according to claim 1, 2 or 3, wherein the at least one sealing element (58) is disposed in a sealing element space (60) formed by a side surface (62, 64) of the inner ring portion and at least one opposite mating surface (66, 68 ) of the seal carrier portion is limited. Guide vane ring according to claim 4, wherein the sealing element space (60) in the axial direction (x) and radial direction (z) is closed. Guide vane ring according to claim 4 or 5, wherein the sealing element space (60) is arranged downstream of the guide vanes (2). Guide vane ring according to one of the preceding claims, wherein the sealing element (58) has a C-shaped profile. Guide vane ring according to one of claims 1 to 6, wherein the sealing element (58) has a V-shaped profile. Guide vane ring according to one of claims 1 to 6, wherein the sealing element (58) has a W-shaped profile. Turbomachine with at least one vane ring (1) according to one of the preceding claims.

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