EP2725200B1 - Guide blade assembly and fluid flow engine - Google Patents

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 plurality of guide vanes which can be pivoted about their main axis or vane axis for setting optimum operating conditions. The adjustable vane row forms with a rotor portion enclosing an inner ring a vane ring. The inner ring serves for internal stabilization and storage of the guide vanes. He can be like 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. The carrier segments are braced together after positioning on the inner ring via circumferentially oriented and located in the hot gas path clamping screws. 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, enter into the rotor-side sealing fins or sealing tips. The installation of the clamping screws is very complex. In addition, the clamping screws require a lot of space and can be sucked in the accidentally released state in the hot gas path.

In the DE 10 2006 024 085 A1 Alternatively, it is proposed to assemble the inner ring from two halves undivided in the axial direction. The half rings are elastically deformable so that they can be unrolled over the bearing journal of the guide vanes mounted in the housing halves. For this purpose, the half rings are biased to a constant clamping radius, positioned in the region of the bearing pin and then relaxed. The US 4395195 A discloses another example of a vane ring of a gas turbine engine. The object of the invention is to provide a vane ring for a turbomachine, which eliminates the aforementioned disadvantages, causes a mutual centering of adjacent seal carrier segments and prevents relative radial displacements of such seal carrier segments. 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 vane ring with the features of patent claim 1 and by a turbomachine having the features of claim 8. An inventive vane ring for a turbomachine has a plurality of rotatable vanes, a static inner ring for radially inner stabilization of the vanes, which consists of at least two ring segments is assembled, and a seal carrier having at least two support segments slidable on the ring segments and which is provided with sealing elements for sealing a radial gap between the inner ring and an opposite rotor section. According to the invention, connecting devices are provided for the automatic connection of adjacent carrier segments in the area of parting lines, each of which has at least two cooperating connecting elements, of which one connecting element is formed on one end of the carrier segment and the corresponding connecting element on the adjacent carrier segment on the other side.

By means of the end-side connecting means, the carrier segments are mutually centered and a mounting clearance between the inner ring and the seal carrier eliminated.

As a result, at least relative radial displacements of the carrier segments and thus the ring segments are prevented, so that such a vane ring has a high concentricity and thus a precisely set radial gap. Radial steps between the adjacent support segments and thus between the sealing elements are effectively prevented. In addition, the assembly compared to the known solution described above after EP 0 947 668 B1 greatly simplified, since the connection to one automatically when pushing the carrier segments or when positioning the respective bladed housing halves to each other when closing the machine housing. An additional step for connecting the carrier segments after their positioning on or at the Ring segments omitted.

In a manufacturing technology easy to produce and easy to assemble montagetechnisch the one connecting elements are in the circumferential direction of the vane ring protruding from the carrier segment connecting tongues and the corresponding connecting elements each have a peripheral contact surface of the adjacent carrier segment for conditioning the connecting tongue.

The connections of the carrier segments in the radial direction can be additionally stabilized if the connecting tongues in the unassembled state of adjacent carrier segments lie radially inward to the contact surfaces. As a result, the connecting tongues brace the carrier segments in the mounted state in the radial direction.

In order to prevent a leakage current between the adjacent carrier segments in the radial direction, the respective connecting tongue can additionally be formed as a sealing element. An effective sealing of the respective parting line can be achieved in that the connecting tongues are plate-like and extend substantially each over an entire axial length of the parting line.

In one embodiment, the connection tongues are a metal sheet fastened to the support segments. In this exemplary embodiment, the connection tongues are produced separately from the carrier segment and are subsequently connected to the respective carrier element, for example by means of a fluid connection such as welding or soldering. The separate production prevents the geometry and production of the carrier segments from having to be changed. On the other hand, the connecting devices can be retrofitted as a retrofit kit for existing vane rings by the separate production. Alternatively, however, the connection tongues can also be designed as an integral component section of the respective carrier segment. In order to prevent that in the unlikely event of detachment of the connecting tongues from the respective carrier segment they are sucked into the turbomachine and cause consequential damage there, the connecting devices are in the mounted state the guide vane ring preferably each arranged in a closed in the axial and radial direction of the vane ring cavity between the inner ring and the seal carrier.

Threading the connecting tongues into the cavities and thus mounting the seal carrier can be simplified if the connecting tongues are cross-sectionally tapered at their free end in the transverse direction.

A turbomachine according to the invention has at least one guide vane ring according to the invention. Due to the concentric position of the sealing elements to the opposite rotor section, such a turbomachine is characterized by a higher compressor efficiency and an upwardly shifted surge line than a turbomachine with a conventional vane ring. In addition, when the connecting means act simultaneously as radial seals, a leakage flow through joints between adjacent seal carrier segments therethrough prevented, which also has a positive effect on the compressor efficiency and the surge limit.

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

Figur 1

einen Axialschnitt durch ein bevorzugtes Ausführungsbeispiel eines erfindungsgemäßen Leitschaufelkranzes, und

Figur 2

einen Schnitt entlang der Linie AA aus Figur 1.

In the following, a preferred embodiment of the invention is explained in more detail with reference to greatly simplified schematic illustrations. Show it:

FIG. 1

an axial section through a preferred embodiment of a guide vane ring according to the invention, and

FIG. 2

a section along the line AA FIG. 1 ,

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, a seal carrier 6 and in a joint area of the seal carrier 6 each have a connection means 8. The vane ring 1 is the stator side in the compressor of the turbomachine arranged and engages around a rotor portion 10 of a rotor which rotates about a m in the flow direction x of a main flow extending machine axis m.

The guide vanes 2 are adjustable about their main axis h extending radially to the machine axis m and each have an airfoil 12, an inner paddle 14 and a bearing journal 16 extending radially inwardly from the paddle 14. In addition, the guide 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 12 are each arranged in a radially outer countersunk portion 18 of the inner ring 4 passing through bearing bore 20. They have a radially inner and extending along the machine axis m bottom 22 and an opposite bottom 22 to the top 24. The top 24 is arranged obliquely to the machine axis m, wherein it extends radially in the flow direction x from inside to outside. It forms in an unadjusted position with an inner ring surface 26 a step-free or almost step-free 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 20 and the inner ring surface 26 and is spaced from the rotor section 10 via a radial gap. It consists of two half rings, each with an arc section of 180 °, which are assembled in the region of a horizontal parting plane of a machine housing of the turbomachine to the inner ring 4. Of course, a stronger segmentation of the inner ring 4 is possible beispielsweie in four ring segments.

The bearing bores 20 respectively pass through the inner ring surface 26 in the radial direction. They each have a radially inner bearing portion 28 for receiving bushings 30 and the radially outer countersink portion 18 for receiving the inner paddle 14th

The bushings 30 are inserted radially from the inside out into the bearing sections 28. They each have a T-shaped cross section with a radially expanded outer collar 32, by means of which they rest in each case on a radially inner peripheral surface 34 of the half rings.

The guide vanes 2 dive with their bearing pins 16 in the bearing bushes 30 and are thus rotatably guided relative to their main axis h in the radial direction. In addition, a sliding disk, not shown, may be screwed onto the bearing journal 16, which in the installed state is arranged between the bearing bushes 30 and the inner blade plates 14 and defines a sliding surface for the guide blades 2.

The inner ring surface 26 extends downstream of the bearing bores 20 via a rear and obliquely to the machine axis m radially from inside to outside employed axial projection 36 of the inner ring 4. Between the axial projection 36 and the blades 12 is formed in each case a radial so-called flag gap 38, to achieve a high efficiency of the turbomachine and a high surge limit is minimized. To set the flag gap 38, 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 take place or by means of axial locking pins which pass through at least one side in inner ring 4 and engage in a corresponding annular groove of the bearing pin 16.

To accommodate the seal carrier 6, the inner ring 4 has a front end-side guide groove 40 and a rear axial guide projection 42, which are each arranged radially inwardly of the inner ring surface 26.

The seal carrier 6 is used for positioning inlet pads 44, 46 for sealing the radial gap between the rotor section 10 and the inner ring 4. It is radially inwardly disposed on the inner ring 4 in a form-fitting manner. He has, as in FIG. 2 shown, preferably two semi-circular support segments 48, 50 which are pushed in the circumferential direction on the ring segments. The carrier segments 48, 50 define in the assembled state of the seal carrier 6 separating joints 52, which lie in only two carrier segments 48, 50 preferably in the horizontal parting plane of the machine housing. The carrier segments 48, 50 each have a U-shaped profile with a viewed in the flow direction x front wall 54, a rear wall 56 and the two walls 54, 56 interconnecting circumferential wall 58th

For fixing the seal carrier 6 to the inner ring 4, the front walls 54 of the support segments 48, 50 each have a front downstream circumferential projection 60 and the rear walls 56 each have a laterally and upstream opened circumferential groove 62. In the assembled state, the peripheral projections 60 engage positively in the front guide grooves 40 of the half rings of the inner ring 4. The rear guide projections 42 of the half rings of the inner ring 4 engage in a positive fashion in the circumferential grooves 58. To enable assembly these form-fitting connections are subject to play.

The inlet pads 44, 46 are inter alia on the inner peripheral side on the circumferential wall 58 and on the other inner peripheral side on a radially inner and rear circumferential extension 64 opposite rotor-side sealing tips or sealing fins 66 on the peripheral wall 58.

The connecting devices 8 are respectively arranged on the end side of the carrier segments 48, 50 and thus in the assembled state in the region of the parting lines 52. They are positioned in cavity 68 between the inner ring 4 and the seal carrier 6. The cavity 68 is bounded in the radial direction by the half rings and the peripheral wall 58 of the carrier segments 48, 50 and in the axial direction by the front wall 54 and the rear wall 56 of the carrier segments 48, 50.

The connecting devices 8 each have two automatically cooperating connecting elements 70, 72. "Automatically or automatically" in the sense of the invention means that when assembling the carrier segments 48, 50 or when mounting or closing the machine housing, the cooperating connecting elements 70, 72 of the connecting devices 8 in each case without further measures with each other. In the exemplary embodiment shown here, one connecting element is in each case a connecting tongue 70 and the connecting element corresponding thereto a contact surface 72. The connecting tongues 70 and the contact surfaces 72 are each formed on opposite end sections of the adjacent carrier segments 48, 50. In the case of only two carrier segments 48, 50, these can be provided at their one end section with a connecting tongue 70 and at their other end section with a contact surface 72. alternative For example, in the case of two carrier segments 48, 50, one carrier segment 48 may each have a connecting tongue 70 at its two end sections and the other carrier segment 50 may each have a contact surface 72 at its two end sections. In the in FIG. 2 In the embodiment shown, a connecting tongue 70 is arranged on one end section of the carrier segment 48 and a contact surface 72 on the opposite end section of the adjacent carrier segment 50.

The connecting tongue 70 is in the embodiment shown, a plate-like metal sheet, which is arranged between the walls 54, 56 on the outer peripheral side of the peripheral wall 58. It extends over the entire extent of the circumferential wall 58 in the direction of the machine axis m and thus substantially over the entire axial length of the respective parting line 52. As a result, the parting line 52 is radially closed, so that the formation of a radial leakage flow is effectively prevented. At the same time thereby the support segments 48, 50 stabilized in the axial direction of the vane ring 1 and relative axial displacements of the support segments 48, 50 to each other prevented, since the connecting tongue 70 laterally against the walls 54, 56 and spaced only in a minimum mounting distance therefrom is.

The connecting tongue 70 has a fastening portion 74, by means of which it is fastened to a peripheral surface of the peripheral wall 58 facing the inner ring 4 in the assembled state and a connecting portion 78 for engagement with the contact surface 72 of the adjacent support segment 50. The connecting portion 78 projects circumferentially over the latter Carrier segment 50 and thus extends over the parting line 52 on the adjacent support segment 50. To stabilize the connection of the support segments 48, 50 may alternatively or additionally be the connecting tongue 70 in the unassembled state of the vane ring radially inward to the contact surface 72.

The contact surface 72 is arranged on the outer peripheral side on the peripheral wall 58 of the adjacent carrier segment 50. It extends over the entire axial extension of the peripheral wall 58 and performs an outer contour of the peripheral wall 58 unchanged. Alternatively, the contact surface 72 may be tangential or wedge-shaped, for example in the circumferential direction, wherein the radial thickness of the peripheral wall in the direction of Dividing line 52 reduced.

In order to avoid obstruction of the carrier segments 48, 50 when the respective connecting device 8 is pushed together, the connecting tongues 70, as in FIG FIG. 2 shown, two each in the sliding direction or in the mounting direction opposite to each other employed guide surfaces 82, 84 have, so that the connecting tabs 72 are cross-sectionally tapered head side in the transverse direction, ie in the direction of the machine axis m.

In order to prevent that the connecting tongues 70 accumulate with their connecting portions 78 when mounting on the collar 32 of the bearing bushes 30 and to prevent the connecting tongues 70 with their fastening portions 74 at least partially close the bearing bores 20, the connecting portions 78 each at their own in the transverse direction extending sides concave recesses 86, 88, each forming a space for receiving the collar 32 of the bushings 30.

In the assembled state, the connection tabs 70 are flat against the contact surfaces 72 and thus cause a centering of the adjacent support segments 48, 50 to each other, a removal of mounting clearance, a concentric arrangement of the seal carrier 6 and the inner ring 4 to the rotor and prevent radial displacement and axial displacement of Carrier segments 48, 50 relative to each other. At the same time, the parting lines 52 are radially sealed by the connection tongues 70, so that the formation of a leakage current between the adjacent support segments 48, 50 is effectively prevented.

In addition, as in FIG. 1 shown, the support segments 48, 50 of the seal carrier 6 with the half rings of the inner ring 4 by radial screws 90 may be interconnected, which are guided by the rear guide projections 42 and are screwed into holes 92 of the rear wall 56.

Apparently, a vane ring for a turbomachine, which has a connection means for automatically connecting adjacent support segments having at least two cooperating connecting elements, of which one connecting element end side to the one support segment and the corresponding connecting elements end is formed on the adjacent carrier segment, and a turbomachine with such a vane ring.

LIST OF REFERENCE NUMBERS

1

vane ring

2

vanes

4

inner ring

6

seal carrier

8th

connecting device

10

rotor section

12

airfoil

14

inner shovel plate

16

pivot

18

lowering section

20

bearing bore

22

bottom

24

top

26

Inner ring surface

28

bearing section

30

bushings

32

collar

34

peripheral surface

36

axial projection

38

flags gap

40

front guide groove

42

rear guide projection

44

inlet lining

46

inlet lining

48

carrier segment

50

carrier segment

52

parting line

54

front wall

56

rear wall

58

peripheral

60

circumferential projection

62

circumferential groove

64

Scope extension

66

sealing fin

68

cavity

70

connecting member

72

corresponding connecting element

74

attachment section

78

connecting portion

82

guide surface

84

guide surface

86

recesses

88

recesses

90

radial screws

92

rear flange

H

Major axis / blade axis

m

machine axis

x

Flow direction / axial direction

Claims (8)

1. Guide vane ring (1) for a turbomachine, comprising a plurality of rotatable guide vanes (2), a static inner ring (4) that is intended for radially inner stabilization of the guide vanes (2) and is assembled from at least two ring segments, and comprising a seal support (6) which has at least two support segments (48, 50) that can be slid onto the ring segments and is provided with sealing elements (44, 46) for sealing a radial gap between the inner ring (4) and an opposing rotor portion (10), the guide vane ring having a connection device (8) in each case for automatically connecting adjacent support segments (48, 50) in the region of parting lines (52), characterized in that the connection element has at least two interacting connection elements (70, 72), of which one connection element (70, 72) is formed on the end face of one support segment (48, 50) and the corresponding connection element (72, 70) is formed on the end face of the adjacent support segment (50, 48).
2. Guide vane ring according to claim 1, wherein one connection element (70, 72) is in each case a connection tongue (70) projecting from one support segment (48, 50) in the peripheral direction of the guide vane ring (1), and the corresponding connection element is in each case a peripheral contact surface (72) of the adjacent support segment (50, 48) for contact with the connection tongue (70).
3. Guide vane ring according to claim 2, wherein the connection tongues (70) are located radially to the inside of the abutment surfaces (72) when adjacent support segments (48, 50) are not mounted.
4. Guide vane ring according to either claim 2 or claim 3, wherein the connection tongues (70) are plate-like and in each case extend substantially over an entire axial length of the parting line (52).
5. Guide vane ring according to any of claims 2, 3 or 4, wherein each connection tongue (70) is a metal sheet secured to one support segment (48, 50).
6. Guide vane ring according to any of the preceding claims, wherein, when the ring is not mounted, the connection devices (8) are arranged in a cavity (68) between the inner ring (4) and the seal support (6), which cavity is closed in the axial and radial directions of the guide vane ring (1).
7. Guide vane ring according to any of claims 2 to 6, wherein the cross section of the free end of the connection tongues (70) tapers in the transverse direction.
8. Turbomachine comprising at least one guide vane ring (1) according to any of the preceding claims.

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