EP3524781B1 - Connecting device for an adjustable vane of a gas turbine - Google Patents

Description

The present invention relates to a connecting device for an adjustable blade of a gas turbine, in particular an aircraft gas turbine, comprising a pin element connected to a relevant blade and a lever element connected to the pin element, the lever element and the pin element being movable together about a pin axis of rotation.

Directional indications such as “axial” or “axial”, “radial” or “radial” and “circumferential” are to be understood in the context of this description as referring to the pivot axis of the connecting device, unless something explicitly or implicitly emerges from the context other results.

In known connecting devices for adjustable blades of gas turbines, a threaded section is formed on the pin element, in particular at its axial end facing away from the blade, or a change in shape is made in some other way, such as bevels and the like, in order to connect the pin section to the lever element can. Examples of this are from EP 2 177 771 A2 or the WO 2015/031058 A1 known. Further examples of connection devices for adjustable guide vanes of gas turbines are shown in US 2004/240990 A1 and US 2008/031729 A1 disclosed.

Current developments in the field of gas turbines, in particular aircraft gas turbines, are such that geometries, such as the flow cross-sections or structures, are reduced in size. As a result, adjustable blades with their pin elements attached to them also have reduced dimensions. Conventional connection systems for adjustable blades, for example via so-called roof slopes, cone geometries or the like. require a reduction in the diameter of the pin element in an axial end section. In return, this no longer allows the use of screws or nuts with a customary minimum diameter of 0.19 or size M5. The object on which the invention is based is seen to be to provide a connecting device in which the above disadvantages can be avoided.

To solve this invention, it is proposed that the connecting device has a tensioning element which is arranged between the lever element and the pin element is such that a non-positive connection between the pin element, the clamping element and the lever element can be or can be produced. This allows a particularly space-saving design of the blade arrangement connected to the connecting device, since fastening means can still be used, but at the same time the blade and its blade journal can be made smaller. Furthermore, the tensioning element ensures a secure transmission of force between the lever element and the pin element, so that the existing adjustment principles can be transferred to smaller compressors or turbines with adjustable guide vanes.

The tensioning element preferably has a plurality of recesses along its circumference, such that a respective elastically movable tensioning section is formed between adjacent recesses. In particular, the tensioning element can be stretched in the assembled state due to the non-positive connection and / or have a pretension.

At least two diametrically opposite recesses in the clamping element can be dimensioned such that they form a clamping receptacle in which the positioning element is received. Accordingly, in an assembled state of the connecting device, the positioning element is arranged in such a way that it is arranged in the clamping receptacle, the pin receptacle and the lever receptacle. The clamping receptacle, the pin receptacle and the lever receptacle can thus advantageously be aligned with one another in a simple manner by the positioning element, without the need for readjustment during assembly.

The clamping sections can be designed in such a way that they have a conical outer contact surface. The radially inner contact surface of the coupling section of the lever element and the radially outer contact surfaces of the clamping sections can bear against one another and can be braced against one another.

According to the invention it is provided that in the connecting device the lever element, the tensioning element and the pin element are aligned with one another by means of a positioning element, the positioning element being received in a pin receptacle and a lever receptacle. The pin receptacle thus serves as a receptacle of the positioning element in the pin element, while the lever receptacle serves as a receptacle for the positioning element in the lever element.

The positioning element can be designed as a plate-like feather key, for example. The positioning element serves in particular to enable an alignment of the lever element and the pin element in the circumferential direction in relation to the pin axis of rotation. This alignment takes place by means of the positioning element before the connecting device is tightened. By using a separate positioning element, a weakening or change in the cross section of the pin element can be avoided, especially in areas in which forces, in particular rotational forces, are transmitted from the lever element to the pin element when the connecting device is assembled.

In an advantageous development it is provided that the pin receptacle and the lever receptacle are arranged in alignment with one another. This enables a particularly simple and inexpensive production of the positioning element and the corresponding receptacles and thus also facilitates assembly. In particular, it can be provided that the positioning element is designed symmetrically to a plane running through the pivot axis of rotation. This also simplifies production and makes it possible not to have to pay attention to an installation direction of the positioning element during assembly.

The pin receptacle can preferably be formed in an axial end section of the pin element. As a result, the positioning element can advantageously be connected to the pin element first during assembly, which facilitates the subsequent arrangement of the lever element, in particular its coupling section, on or on the pin element. For example, the pin receptacle is designed as a slot. The slot can have an axial depth that is somewhat greater than the axial extent or height of the positioning element that passes through the pin receptacle.

In order to tighten the connecting device, the tensioning element can have a threaded section to which a nut can be fastened or is fastened. The threaded section is located on an axial section of the tensioning element which faces away from the pin element.

The lever element can have a sleeve-like coupling section, the coupling section and the pin element being arranged concentrically to one another. The coupling section can in particular be designed circular. Externally, the coupling section has an essentially cylindrical shape.

The lever receptacle can be formed in an axial edge section of the coupling section. The lever receptacle can be formed by two lever receptacle sections lying diametrically opposite one another. The lever receiving sections can be provided as radially extending slots in the edge section. When the connecting device is in an assembled state, the positioning element rests in the lever receiving sections. In particular if the pin receptacle is arranged in a pin end section, the lever receptacle can simply be pushed over the positioning element, so that an exact alignment of the lever or an additional clamping element described in more detail below is always made possible.

The coupling section can have a radially inner contact surface that is conical. In particular, the radially inner contact surface faces the pin element. For example, the contact surface surrounds the pin element, there being a distance between the contact surface and the pin element.

The connecting device can have a securing sleeve which is arranged in the axial direction on the coupling section. The securing sleeve can have a peripheral edge which extends somewhat in the axial direction over the coupling section of the lever element. This can ensure that the positioning element cannot be removed from the connecting device in the assembled state of the connecting device.

The securing sleeve can be arranged between the nut and the coupling section in such a way that a force exerted by the nut is transmitted in the axial direction to the securing sleeve and the coupling section. Due to the interaction of its radially inner contact surface with the contact surfaces of the clamping sections, an axial force acting on the coupling section of the lever element results in the clamping sections being pressed against the pin element essentially in the radial direction, so that the pin element is held by the clamping sections with a force fit.

In the assembled state of the connecting device, the positioning element can be accommodated without force transmission. By using the tensioning element, a non-positive connection can be established between the lever element and the pin element, the positioning element serving for the correct alignment of the lever element and the pin element to one another during assembly. In the event of a rotary movement to be transmitted from the lever element to the pin element about the pin axis of rotation, the positioning element is also rotated, but it does not transfer any forces from the lever element to the pin element.

For the sake of completeness, it is pointed out that the blades discussed here can in particular be adjustable blades of a compressor of the gas turbine.

The invention also relates to a gas turbine, in particular an aircraft gas turbine, with a plurality of adjustable blades arranged next to one another in the circumferential direction of the turbine, in particular guide blades, with a connecting device according to one of the preceding claims being arranged on each blade, and wherein the lever elements of the connecting devices with one along the circumferential direction of the gas turbine movable adjusting ring are coupled.

The adjustable blades arranged next to one another in the circumferential direction of the turbine can be assigned to a compressor stage. Such an adjustable blade ring can also be provided several times on a gas turbine, so that a ring with adjustable blades can be provided for any type of compressor, such as low-pressure, medium-pressure or high-pressure compressor at any compressor stage.

• Fig. 1 zeigt in einer vereinfachten schematischen Darstellung ein Prinzipbild einer Fluggasturbine.
• Fig. 2 zeigt in einer schematischen perspektivischen Darstellung, die teilweise geschnitten ist, eine erfindungsgemäße Verbindungseinrichtung für eine verstellbare Schaufel einer Gasturbine.
• Fig. 3 zeigt in einer schematischen perspektivischen Darstellung ein Hebelelement, ein Positionierungselement und ein Zapfenelement der Verbindungseinrichtung der Fig. 2.
• Fig. 4 zeigt in einer schematischen perspektivischen Darstellung ein Spannelement der Verbindungseinrichtung der Fig. 2.
• Fig. 5 zeigt in einer schematischen Schnittansicht, die etwa einer Schnittlinie V-V der Fig. 2 entspricht, einen Ausschnitt einer Gasturbine mit einer Verbindungseinrichtung und mit einem zugeordneten Verstellring.
• Fig. 6 zeigt einen vergrößerten Bereich entsprechend dem gestrichelt umrandeten Bereich VI der Fig. 5.

The invention is described below by way of example and not in a restrictive manner with reference to the accompanying figures.

• Fig. 1 shows in a simplified schematic representation a basic diagram of an aircraft gas turbine.
• Fig. 2 shows in a schematic perspective illustration, which is partially cut, a connection device according to the invention for an adjustable blade of a gas turbine.
• Fig. 3 shows in a schematic perspective illustration a lever element, a positioning element and a pin element of the connecting device of FIG Fig. 2 .
• Fig. 4 shows in a schematic perspective illustration a clamping element of the connecting device of FIG Fig. 2 .
• Fig. 5 shows in a schematic sectional view which is approximately a section line VV of Fig. 2 corresponds to a section of a gas turbine with a connecting device and an associated adjusting ring.
• Fig. 6 shows an enlarged area corresponding to the area VI of FIG Fig. 5 .

Fig. 1 shows schematically and simplified an aircraft gas turbine 10, which is illustrated purely by way of example as a turbofan engine. The gas turbine 10 comprises a fan 12 which is surrounded by an indicated jacket 14. In the axial direction TAR of the gas turbine 10, the fan 12 is followed by a compressor 16, which is received in an indicated inner housing 18 and can be designed in one or more stages. The combustion chamber 20 adjoins the compressor 16. Hot exhaust gas flowing out of the combustion chamber then flows through the adjoining turbine 22, which can be designed in one or more stages. In the present example, the turbine 22 comprises a high-pressure turbine 24 and a low-pressure turbine 26. A hollow shaft 28 connects the high-pressure turbine 24 to the compressor 16, in particular a high-pressure compressor 29, so that these are driven or rotated together. A further inner shaft 30 in the radial direction TRR of the turbine connects the low-pressure turbine 26 to the fan 12 and to a low-pressure compressor 32 here, so that these are driven or rotated together. A thrust nozzle 33, which is only indicated here, adjoins the turbine 22.

In the illustrated example of an aircraft gas turbine 10, an intermediate turbine housing 34 is arranged between the high-pressure turbine 24 and the low-pressure turbine 26 and is arranged around the shafts 28, 30. In its radially outer region 36, the intermediate turbine housing 34 has hot exhaust gases from the high-pressure turbine 24 flowing through it. The hot exhaust gas then passes into an annular space 38 of the low-pressure turbine 26. Rotor blade rings 27 of the compressors 28, 32 and the turbines 24, 26 are shown by way of example. Usually available For reasons of clarity, guide vane rings 31 are shown by way of example only in the case of the compressor 32.

The following description of an embodiment of the invention relates in particular to adjustable guide vanes which, for example, can be part of an overall adjustable guide vane ring 31. Such adjustable guide vane rings 31 can also be provided in other compressors or possibly also in turbines, even if this is shown in FIG Fig. 1 is shown only as an example for the compressor 32.

Fig. 2 shows in a schematic perspective illustration a connecting device 50 for an adjustable guide vane of a gas turbine. The guide vane 51, only partially indicated here by dashed lines, adjoins a pin element 52 in the axial direction AR of the connecting device 50, which in FIG Fig. 2 is only partially shown. The pin element 52 and the associated vane 51, in particular the guide vane, are usually connected to one another in one piece.

The connecting device 50 comprises a lever element 54. The lever element 54 is shown in FIG Fig. 2 (and in Fig. 1 ) is only partially shown, the lever element 54 being illustrated cut off at 56. The lever element 54 is set up to rotate the pin element 52 about the pin rotation axis ZD parallel to the axial direction AR when the connecting device 50 is in an assembled state.

From the Fig. 3 it can be seen that the pin element 52 has a pin receptacle 60 at its axial end 58 facing away from the blade 51. The pin receptacle is designed in particular as a slot. The lever element 54 has a sleeve-like coupling section 62. The coupling section 62 and the pin element 52 are in particular arranged concentrically to one another. A lever receptacle 66 is formed in an axial edge section 64 of the coupling section 62. The lever receptacle 66 is formed in particular by two diametrically opposite lever receptacle sections 66a, 66b.

A positioning element 68 is received in the lever receptacle 66 and the pin receptacle 60. The positioning element 68 serves to align the pin element 52 and the lever element 54 with respect to one another in relation to the circumferential direction UR of the connecting device 50. For this purpose, in particular the lever receptacle 66 or the lever receptacle sections 66a, 66b and the pin receptacle 60 are aligned with one another so that the positioning element 68 is received in the lever receptacle 66 and the pin receptacle 60. The positioning element 68 is designed in particular as a plate-like or flat-bar-like component. The positioning element 68 can also be referred to as a feather key.

The connecting device 50 also has a tensioning element 70, which is shown in FIG Fig. 3 alone and in Fig. 1 is shown together with other components of the connecting device 50. The tensioning element 70 has a plurality of tensioning sections 74a, 74b, 74c at its axial end 72 facing the blade 51. In the example shown, the clamping element 70 has four clamping sections, of which, however, in the Fig. 1 and 3 only the three clamping sections 74a, 74b, 74c are visible. It should be noted that the tensioning element 70 could also have a different number of tensioning sections, for example six or eight.

A respective recess 76a and 76b is provided between two adjacent clamping sections 74a, 74b and 74a, 74c. The clamping sections 74a, 74b, 74c are, in particular, elastically movable or deflectable in the radial direction, in particular towards and away from the pin element 52. The recess 76b and a further recess diametrically opposite it, which in the selected representation of the Fig. 3 is not visible, are dimensioned in such a way that they form a clamping receptacle 78 in which the positioning element 68 can be received during the assembly of the connecting device 50 or is received in the assembled state of the connecting device 50.

The clamping sections 74a, 74b, 74c have a respective outer contact surface 80. The contact surfaces 80 are designed to be conical along the axial direction AR. In other words, the clamping element 70 has a changing diameter in the area of its clamping sections 74a, 74b, 74c. In an assembled state of the connecting device 50, the outer contact surfaces 80 are in contact with a radially inner contact surface 82 of the lever element 54. The radially inner contact surface 82 is arranged in particular in the region of the coupling section 62. Furthermore, the radially inner contact surface 82 can have a conical shape. Correspondingly, the sleeve-like coupling section 62 has a changing inner diameter in the area of the inner contact surface 82.

The radially outer contact surface 80 of the clamping sections 74a, 74b, 74c and the radially inner contact surface 82 of the coupling section 62 are designed to be complementary to one another. The inner diameter or inner radius of the coupling section 62 and the outer diameter of all clamping sections 74a, 74b, 74c or the outer radius of the clamping sections 74a, 74b, 74c increase in the direction of the blade 51 ( Fig. 2 ) to.

The clamping element 70 has a threaded section 84 axially adjoining the clamping sections 74a, 74b, 74c. The threaded portion 84 has an in the Figures 1 and 3 external thread, not shown. A nut 86 can be or is connected to the threaded section 84, as shown in FIG Fig. 1 is shown. In the assembled state of the connecting device 50, a locking sleeve 88 is arranged in the axial direction between the nut 86 and the lever element 54, in particular the clamping section 62. A force exerted by the nut 86 in the axial direction AR is transmitted to the securing sleeve 88 and the coupling section 62. As a result of the locking force of the nut 86 acting in the axial direction, the conical inner contact surface 82 of the coupling section 62 is pressed against the conical outer contact surface 80 of the clamping element 70. As a result, the clamping sections 74a, 74b, 74c are pressed radially inward against the pin section. Correspondingly, when the nut 86 is tightened, a non-positive connection (bracing) takes place between the lever element 54 and the journal section 52 by means of the tensioning element 70.

The in Fig. 2 The assembled state of the connecting device 50 shown in FIG Fig. 5 in a sectional view approximately corresponding to the section line VV of Fig. 1 shown. In this sectional view of the Fig. 5 the connecting device 50 is in an outer region of structural components 90 of a gas turbine 10 ( Fig. 1 ), in particular aircraft gas turbine attached. The structural components 90 can for example be part of an inner housing 18, as shown in FIG Fig. 1 is illustrated. In the Fig. 5 the same reference numerals are used as in Figures 2 to 4 in order to designate the same elements, even if these are not necessarily with reference to the Fig. 5 be described again. In this respect, the previous description of Figs. 2 to 4 also in conjunction with the Fig. 5 can be read and understood.

In Fig. 5 the lever element 54 is shown completely (not cut off). The lever element 54 has a further coupling section 92 at its end facing away from the connecting device 50. The coupling section 92 is connected to an adjustment device 94. The adjustment device 94 comprises an adjustment ring 96 and a plurality of adjustment pins 98. The adjustment pins 98 and the adjustment ring 96 can be moved back and forth along a turbine circumference. This translational adjustment movement along the circumferential direction of the turbine causes the lever element 54 to pivot about the axis of rotation ZD of the pin element 52. As a result, a blade 51 connected to the pin element 52 ( Fig. 2 ) can be rotated to a desired position.

The tensioning element 70 of the connecting device 50 rests on a guide sleeve 100. In this example, the guide sleeve also forms a radial bearing for the journal element 52. The axial direction AR of the connecting device corresponds to a radial direction TRR of the gas turbine in relation to the gas turbine.

Fig. 6 shows an enlarged area approximately corresponding to the dashed area VI of FIG Fig. 5 . The Fig. 6 serves in particular to describe the proportions of the positioning element 68 to other elements.

In relation to the connecting device 50, the positioning element 68 has a length VL extending in the radial direction RR. The length VL of the positioning element 68 is selected such that it is somewhat smaller than the diameter DK of the essentially circular coupling section 62 or the outer diameter of the axial edge section 64, which is annular. The positioning element 68 has a width VB which is smaller than the axial extent or depth ZT of the pin receptacle 60. Furthermore, the width VB of the positioning element 68 is also selected such that it is smaller than the axial extent or depth HT of the lever receptacle 66 or of the individual lever receptacle sections 66a, 66b.

The securing sleeve 88 has an edge section 102 which has an axial length which is greater than the width of the positioning element 68. The edge section 102 rests with its axially lower end on an outer circumference of the coupling section 62. This ensures that the positioning element 68 cannot be removed from the connecting device 50 in the radial direction.

As can be seen from the described proportions of the positioning element 68 to other elements of the connecting device 50, the positioning element 68 is received essentially without force transmission in the assembled state of the connecting device 50. In particular, the positioning element 68 does not transmit any rotational movements introduced by the lever element 54 to the pin element 52. The forces acting in the axial direction AR by the nut 86 are transmitted via the locking sleeve 88, the lever element 54 or its coupling section 62 on the clamping element 70 or its clamping sections 74a to 74d, so that the clamping sections 74a to 74d are pressed against the pin element 52. The positioning element 68 is dimensioned in such a way that, when the connecting device 50 is assembled, it enables the pin element 52, lever element 54 and tensioning element 70 to be correctly positioned relative to one another, in particular in the circumferential direction UR of the connecting device 50, but that it is not included in the power transmission path when it is assembled State of the connecting device 50 a non-positive connection between the lever element 54 and the pin portion 52 is established.

List of reference symbols

10

Aircraft gas turbine

12

fan

14th

coat

16

compressor

18th

inner casing

20th

Combustion chamber

22nd

turbine

24

High pressure turbine

26th

Low pressure turbine

27

Rotor blade ring

28

Hollow shaft

29

High pressure compressor

30th

wave

31

Guide vane ring

32

Low pressure compressor

33

Thrust nozzle

34

Turbine center frame

36

outer area

38

Annulus

50

Connecting device

51

shovel

52

Tenon element

54

Lever element

56

Area of the cut lever element

58

axial end of the pin element

60

Journal mount

62

Coupling section

64

axial edge section

66

Lever mount

66a / b

Lever receiving section

68

Positioning element

70

Clamping element

72

axial end

74a-d

Clamping section

76a / b

Recess

78

Clamping fixture

80

radially outer contact surface

82

radially inner contact surface

84

Threaded section

86

mother

88

Locking sleeve

90

Structural component

92

Coupling section

94

Adjusting device

96

Adjustment ring

98

Adjustment pin

100

Guide sleeve

102

Edge section

Claims (14)

1. Connecting device (50) of an adjustable vane (51) of a gas turbine (10), in particular an aircraft gas turbine, comprising:

   a pin element (52) connected to a relevant vane (51);

   a lever element (54) connected to the pin element (52), the lever element (54) and the pin element (52) being movable together about a pin rotation axis (ZD);

   a clamping element (70) being provided, which is arranged between the lever element (54) and the pin element (52) such that a frictional connection can be or is produced between the pin element (52), the clamping element (70) and the lever element (54), characterized in that the lever element (54), the clamping element (70) and the pin element (52) are aligned with one another by means of a positioning element (68), the positioning element (68) being accommodated in a pin receptacle (60) and a lever receptacle (66, 66a, 66b).
2. Connecting device according to claim 1, wherein the clamping element (70) has a plurality of recesses (76a, 76b) along its circumference, such that an elastically movable clamping portion (74a-d) is formed between adjacent recesses (76a, 76b).
3. Connecting device according to either claim 1 or claim 2, wherein at least two diametrically opposite recesses (76a) arranged in the clamping element (70) are dimensioned such that they form a clamping receptacle (78) in which the positioning element (68) is accommodated.
4. Connecting device according to either claim 2 or claim 3, wherein the clamping portions (74a-d) are formed such that they have a conical outer contact surface (80).
5. Connecting device according to any of the preceding claims, wherein the pin receptacle (60) and the lever receptacle (66, 66a, 66b) are arranged in alignment with one another.
6. Connecting device according to any of the preceding claims, wherein the pin receptacle (60) is formed in an axial end portion (58) of the pin element (52).
7. Connecting device according to any of the preceding claims, wherein the lever receptacle (66, 66a, 66b) is formed by two diametrically opposite lever receptacle portions (66a, 66b).
8. Connecting device according to any of the preceding claims, wherein the lever element (54) has a sleeve-like coupling portion (62), wherein the coupling portion (62) and the pin element (52) are arranged concentrically with respect to one another.
9. Connecting device according to claim 8, wherein the lever receptacle (60, 60a, 60b) is formed in an axial edge portion (64) of the coupling portion (62).
10. Connecting device according to either claim 8 or claim 9, wherein the coupling portion (62) has a radial inner contact surface (82) which is conical.
11. Connecting device according to any of claims 8 to 10 having a securing sleeve (88) which is arranged on the coupling portion (62) in the axial direction (AR).
12. Connecting device according to claim 10 having at least the features of claim 4, wherein the contact surface (82) of the coupling portion (62) of the lever element (54) and the contact surfaces (80) of the clamping portions (74a-d) abut one another and can be or are braced against one another.
13. Connecting device according to any of the preceding claims, wherein the positioning element (68) is accommodated in the assembled state of the connecting device (50) such that force is not transmitted.
14. Gas turbine (10), in particular an aircraft gas turbine, having a plurality of adjustable vanes (51), in particular guide vanes, arranged one next to the other in the circumferential direction, wherein a connecting device (50) according to any of the preceding claims is arranged on each blade, and wherein the lever elements (54) of the connecting devices (50) are coupled to an adjusting ring (96) which is movable in the circumferential direction of the gas turbine (10).

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