EP3524781A1 - Connecting device for an adjustable vane of a gas turbine - Google Patents

Abstract

Described is a connecting device (50) for an adjustable blade (51) of a gas turbine (10), in particular an aircraft gas turbine, comprising:
a pin member (52) connected to a respective blade (51);
a lever member (54) connected to the pin member (52), the lever member (54) and the pin member (52) being movable in common about a pin rotation axis (ZD). It is provided that the lever element (54) and the pin element (52) by means of a positioning element (68) are aligned with each other, wherein the positioning element (68) in a pin receptacle (60) and a lever receptacle (66, 66a, 66b) is received , An associated gas turbine is also presented.

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 member connected to a respective blade and a lever member connected to the pin member, wherein the lever member and the pin member are movable together about a pin rotation axis.

Directional details such as "axial" or "axial", "radial" or "radial" and "circumferential" are to be understood in the context of this description with respect to the pin rotation axis of the connection device, unless the context explicitly or implicitly something other results.

In known connecting devices for adjustable blades of gas turbines, a threaded portion is formed on the pin member, in particular at its axial end which is remote from the blade, or otherwise made a change in shape, such as bevels and the like to connect the pin portion with the lever member can. Examples of this are from the EP 2 177 771 A2 or the WO 2015/031058 A1 known.

Recent developments in the field of gas turbines, in particular aircraft gas turbines, go to the fact that geometries such as the flow cross-sections, or structures are reduced. This has the consequence that also adjustable blades with their attached pin elements have reduced dimensions. Conventional connection systems for adjustable blades, for example via so-called roof pitches, cone geometries or similar. require a reduction of its diameter in an axial end portion of the pin member. In return, this no longer permits the use of screws or nuts with a usual minimum diameter of 0.19 or M5 size.

The object underlying the invention is seen 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 clamping element which is arranged between the lever element and the pin element is, so that a frictional connection between the pin member, the clamping element and the lever member can be produced or manufactured. This allows a particularly space-saving design of the connected to the connecting device blade assembly, as further fastening means can be used, but at the same time the blade and the blade pin can be made smaller. Furthermore, as a result of the tensioning element, a safe power transmission between the lever element and the pin element, so that the existing Verstellprinzipien can be transferred to smaller compressors or turbines with Verstellleitschaufeln.

Preferably, the clamping element has a plurality of recesses along its circumference, such that a respective elastically movable clamping section is formed between adjacent recesses. In particular, the clamping element may be stretched in the assembled state due to the frictional connection and / or have a bias.

At least two diametrically opposed recesses in the clamping element can be dimensioned such that they form a clamping receptacle in which the positioning element is received. Accordingly, the positioning element is arranged in an assembled state of the connecting device so that it is arranged in the clamping receptacle, the pin receptacle and the lever receptacle. Thus, advantageously, the clamping receptacle, the pin receptacle and the lever receptacle can be aligned in a simple manner to each other by the positioning without a readjustment during assembly is necessary.

The clamping portions may be formed such that they have a conical outer contact surface. In this case, the radially inner contact surface of the coupling portion of the lever member and the radially outer contact surfaces of the clamping portions abut each other and be mutually braced.

In an advantageous development of the invention it is provided that in the connection device, the lever element and the pin member are aligned by means of a positioning element to each other, wherein the positioning element is received in a pin receiving 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 of the positioning element in the lever element.

The positioning element may be formed, for example, as a plate-like key. The positioning element is used in particular to allow alignment of the lever element and the pin element in the circumferential direction with respect to the pin rotation axis. In this case, this alignment takes place by means of the positioning element before the connection device is tightened. By using a separate positioning element weakening or changing the cross section of the pin element can be avoided in particular in areas in which forces, in particular rotational forces are transmitted from the lever element to the pin member in the assembled state of the connecting device.

In an advantageous development, it is provided that the pin receptacle and the lever receptacle are arranged in alignment with one another. This allows a particularly simple and cost-effective production of the positioning and the corresponding recordings and thus facilitates the assembly. In particular, it can be provided that the positioning element is formed symmetrically to a plane passing through the pin rotation axis. This also facilitates the production and makes it possible to disregard an installation direction of the positioning during assembly.

The pin receptacle may preferably be formed in an axial end portion of the pin member. As a result, the positioning element can advantageously be connected first to the pin element during assembly, which facilitates subsequent placement 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 may have an axial depth which is slightly larger than the axial extent or height of the positioning element, which passes through the pin receptacle.

To tighten the connecting device, the clamping element may have a threaded portion to which a nut is fastened or fastened. The threaded portion is located at an axial portion of the clamping element, which faces away from the pin member.

The lever element may have a sleeve-like coupling portion, wherein the coupling portion and the pin member are arranged concentrically with each other. The coupling portion may be formed in particular circular. Externally, the coupling portion has a substantially cylindrical shape.

The lever receptacle can be formed in an axial edge section of the coupling section. In this case, the lever receptacle may be formed by two diametrically opposite lever receiving portions. The lever receiving portions may be provided as radially extending slots in the edge portion. The positioning member is in an assembled state of the connecting means in the lever receiving portions. In particular, when the pin receptacle is arranged in a pin end portion, the lever holder can simply slide over the positioning, so that always an exact alignment of the lever or an additional clamping element described in more detail below is made possible.

The coupling portion may have a radially inner contact surface, which is conical. In particular, the radially inner contact surface faces the pin element. For example, the contact surface surrounds the pin member, wherein between the contact surface and the pin member a distance is present.

The connecting device may comprise a securing sleeve, which is arranged in the axial direction on the coupling portion. The securing sleeve may have a peripheral edge which extends in the axial direction slightly above the coupling portion of the lever member. This can ensure that the positioning element in the assembled state of the connecting device can not be removed from this.

The locking sleeve may be disposed between the nut and the coupling portion such that a force exerted by the nut is transmitted in the axial direction to the locking sleeve and the coupling portion. 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 substantially presses the clamping sections radially into the pin element, so that the pin element is frictionally held by the clamping sections.

The positioning element can be received without force transmission in the assembled state of the connecting device. By the use of the clamping element, a frictional connection between the lever element and the pin element can be produced, wherein the positioning element during assembly for correct alignment of the lever element and the pin member to each other. In one of the lever element to be transmitted to the pin element rotational movement about the pin rotation axis, the positioning element is rotated, but it does not transmit any forces from the lever element on the pin member.

For the sake of completeness, it is pointed out that the blades mentioned here can be, in particular, 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 adjacently arranged in the turbine circumferential direction adjustable blades, in particular vanes, wherein on each blade a connecting device is arranged according to one of the preceding claims, and wherein the lever elements of the connecting means with a along the circumferential direction of the gas turbine are coupled movable adjusting ring.

The adjacently arranged in the turbine circumferential direction adjustable blades 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 on any compressor stages.

• 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 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 will be described below by way of example and not limitation with reference to the attached figures.

• Fig. 1 shows in a simplified schematic representation of a schematic diagram of an aircraft gas turbine.
• Fig. 2 shows in a schematic perspective view, which is partially cut, a connecting device for an adjustable blade of a gas turbine.
• Fig. 3 shows a schematic perspective view of a lever element, a positioning element and a pin member of the connecting device of Fig. 2 ,
• Fig. 4 shows a schematic perspective view of a clamping element of the connecting device of Fig. 2 ,
• Fig. 5 shows in a schematic sectional view, approximately a section line VV of Fig. 2 corresponds to a section of a gas turbine with a connecting device and with an associated adjusting ring.
• Fig. 6 shows an enlarged area corresponding to the dashed rimmed area VI of 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 compressor 12 is adjoined by a compressor 16, which is accommodated in an indicated inner housing 18 and may be of single-stage or multi-stage design. At the compressor 16, the combustion chamber 20 connects. Hot exhaust gas flowing out of the combustion chamber then flows through the adjoining turbine 22, which may be designed in one or more stages. In the present example, the turbine 22 includes a high-pressure turbine 24 and a low-pressure turbine 26. A hollow shaft 28 connects the high-pressure turbine 24 with the compressor 16, in particular a high-pressure compressor 29 so that they are driven together or rotated. A further internal shaft 30 in the radial direction TRR of the turbine connects the low-pressure turbine 26 with the fan 12 and with a low-pressure compressor 32, so that they are driven together or rotated. The turbine 22 is followed by a thrust nozzle 33, which is only indicated here.

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

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

Fig. 2 shows a schematic perspective view of a connecting device 50 for an adjustable guide vane of a gas turbine. The guide vane 51, which is indicated here only partially and in broken lines, adjoins in the axial direction AR of the connecting device 50 a pin element 52, which in the Fig. 2 only partially shown. Usually, the pin member 52 and the associated blade 51, in particular guide vane, are integrally connected to one another.

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

From the Fig. 3 It can be seen that the pin member 52 has a pin receptacle 60 at its end remote from the blade 51 axial end 58. The pin receptacle is designed in particular as a slot. The lever element 54 has a sleeve-like coupling portion 62. The coupling portion 62 and the pin member 52 are in particular arranged concentrically with each other. In an axial edge portion 64 of the coupling portion 62, a lever receptacle 66 is formed. The lever receptacle 66 is formed in particular by two diametrically opposite lever receiving portions 66a, 66b.

In the lever receptacle 66 and the pin receptacle 60, a positioning element 68 is received. The positioning member 68 serves to align the pin member 52 and the lever member 54 with respect to the circumferential direction UR of the connecting device 50 to each other. For this purpose, in particular the lever holder 66 and the lever receiving portions 66a, 66b and the pin receptacle 60 aligned with each other, so that the positioning member 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-rod-like component. The positioning element 68 may also be referred to as a feather key.

The connecting device 50 further comprises a clamping element 70, which in Fig. 3 alone and in Fig. 1 is shown together with other components of the connecting device 50. The clamping element 70 has at its the blade 51 facing the axial end 72 a plurality of clamping portions 74a, 74b, 74c. 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 clamping element 70 could also have a different number of clamping sections, for example six or eight.

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

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

The radially outer contact surface 80 of the clamping portions 74a, 74b, 74c and the radially inner contact surface 82 of the coupling portion 62 are formed complementary to each other.

In this case, the inner diameter or inner radius of the coupling section 62 and the outer diameter of all the clamping sections 74a, 74b, 74c or the outer radius of the clamping sections 74a, 74b, 74c in the direction of the blade 51 (FIGS. Fig. 2 ) too.

The clamping element 70 has an axially adjoining the clamping portions 74a, 74b, 74c threaded portion 84. The threaded portion 84 has a in the FIGS. 1 and 3 not shown external thread on. With the threaded portion 84, a nut 86 is connectable or connected, as in Fig. 1 is shown. In the assembled state of the connecting device 50, a securing sleeve 88 is arranged in the axial direction between the nut 86 and the lever element 54, in particular the clamping portion 62. A force exerted by the nut 86 in the axial direction AR is transmitted to the locking sleeve 88 and the coupling portion 62. By the axially acting locking force of the nut 86, the conical inner contact surface 82 of the coupling portion 62 is pressed against the conical outer contact surface 80 of the clamping element 70. As a result, the clamping portions 74a, 74b, 74c are pressed radially inwardly against the pin portion. Accordingly, when tightening the nut 86, a frictional connection (clamping) between the lever member 54 and pin portion 52 by means of the clamping element 70th

The in Fig. 2 shown assembled state of the connecting device 50 is in 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 is the connection device 50 in an outer region of structural components 90 of a gas turbine 10 (FIG. Fig. 1 ), in particular aircraft gas turbine, attached. For example, the structural members 90 may be part of an inner housing 18 as shown in FIG Fig. 1 is illustrated. In the Fig. 5 are the same reference numerals used as in the FIGS. 2 to 4 to designate the same elements, although not necessarily with reference to the Fig. 5 be described again. In that regard, the previous description of the Fig. 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 remote from the connecting device 50. The coupling portion 92 is connected to an adjusting device 94. The adjusting device 94 comprises an adjusting ring 96 and a plurality of adjusting pins 98. The adjusting pins 98 and the adjusting ring 96 are movable back and forth along a turbine circumference. This translational adjustment movement along the circumferential direction the turbine causes a pivoting of the lever element 54 about the axis of rotation ZD of the pin member 52. As a result, a connected to the pin member 52 blade 51 (FIG. Fig. 2 ) are rotated to a desired position.

The clamping element 70 of the connecting device 50 rests on a guide sleeve 100. The guide sleeve forms in this example, a radial bearing for the pin member 52. The axial direction AR of the connecting device corresponds with respect to the gas turbine a radial direction TRR of the gas turbine.

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

Relative to the connection device 50, the positioning element 68 has a length VL extending in the radial direction RR. The length VL of the positioning member 68 is set to be slightly smaller than the diameter DK of the substantially circular coupling portion 62 and the outer diameter of the axial edge portion 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 so that it is smaller than the axial extent or depth HT of the lever receptacle 66 or the individual lever receiving portions 66a, 66b.

The securing sleeve 88 has an edge portion 102 which has an axial length which is greater than the width of the positioning element 68. The edge portion 102 bears with its axially lower end against an outer circumference of the coupling portion 62. This ensures that the positioning member 68 is not removable in the radial direction of the connecting device 50.

As is apparent from the described proportions of the positioning element 68 to other elements of the connecting device 50, the positioning element 68 is received in the assembled state of the connecting device 50 substantially force-transfer free. In particular, the positioning element 68 does not transmit rotational movements introduced by the lever element 54 onto the pin element 52. The forces acting in the axial direction AR from the utter 86 are transmitted via the securing sleeve 88, the lever member 54 and its coupling portion 62 on the clamping element 70 and its clamping portions 74a to 74d, so that the clamping portions 74a to 74d are pressed against the pin member 52. In this case, the positioning member 68 is dimensioned so that when assembling the connecting device 50, a correct positioning of pin member 52, lever member 54 and clamping element 70 allows each other, in particular in the circumferential direction UR of the connecting device 50, but that it is not included in the power transmission when assembled State of the connecting device 50 is a frictional connection between the lever member 54 and the pin portion 52 is made.

LIST OF REFERENCE NUMBERS

10

Aircraft gas turbine

12

fan

14

coat

16

compressor

18

inner casing

20

combustion chamber

22

turbine

24

High-pressure turbine

26

Low-pressure turbine

27

Blade ring

28

hollow shaft

29

High-pressure compressors

30

wave

31

vane ring

32

Low-pressure compressor

33

exhaust nozzle

34

Turbine center frame

36

outer area

38

annulus

50

connecting device

51

shovel

52

pin element

54

lever member

56

Area of the cut lever element

58

axial end of the pin member

60

pin receiver

62

coupling portion

64

axial edge section

66

lever accommodation

66a / b

Lever receiving portion

68

positioner

70

clamping element

72

axial end

74a-d

clamping section

76a / b

recess

78

chip receiver

80

radially outer contact surface

82

radially inner contact surface

84

threaded portion

86

mother

88

securing sleeve

90

structural component

92

coupling portion

94

adjustment

96

adjusting

98

adjustment peg

100

guide sleeve

102

edge section

Claims (15)

Connecting device (50) for an adjustable blade (51) of a gas turbine (10), in particular an aircraft gas turbine, comprising: a pin member (52) connected to a respective blade (51); a lever member (54) connected to the pin member (52), the lever member (54) and the pin member (52) being movable in common about a pin rotation axis (ZD); characterized in that a clamping element (70) is provided, which is arranged between the lever element (54) and the pin element (52), such that a frictional connection between the pin element (52), the clamping element (70) and the lever element (54) can be produced or produced is. Connecting device according to claim 1, wherein the clamping element (70) along its circumference a plurality of recesses (76a, 76b), such that between adjacent recesses (76a, 76b), a respective elastically movable clamping portion (74a-d) is formed. Connecting device according to claim 1 or 2, wherein at least two diametrically opposed, in the clamping element (70) arranged recesses (76a) are dimensioned such that they form a clamping receptacle (78) in which the positioning element (68) is accommodated. A connecting device according to claim 2 or 3, wherein the clamping portions (74a-d) are formed to have a tapered outer contact surface (80). Connecting device according to one of the preceding claims, wherein the lever element (54) and the pin element (52) by means of a positioning element (68) are aligned with each other, wherein the positioning element (68) in a pin receptacle (60) and a lever receptacle (66, 66a, 66b ) is recorded. Connecting device according to claim 5, wherein the pin receptacle (60) and the lever receptacle (66, 66a, 66b) are arranged in alignment with each other. Connecting device according to one of the preceding claims, wherein the pin receptacle (60) in an axial end portion (58) of the pin member (52) is formed. Connecting device according to one of the preceding claims, wherein the lever receptacle (66, 66a, 66b) by two diametrically opposed lever receiving portions (66a, 66b) is formed. Connecting device according to one of the preceding claims, wherein the lever member (54) has a sleeve-like coupling portion (62), wherein the coupling portion (62) and the pin member (52) are arranged concentrically with each other. Connecting device according to claim 9, wherein the lever receptacle (60, 60a, 60b) in an axial edge portion (64) of the coupling portion (62) is formed. A connector according to claim 6 or 7, wherein the coupling portion (62) has a radially inner contact surface (82) which is conical. Connecting device according to one of claims 6 to 8 with a securing sleeve (88) which is arranged in the axial direction (AR) on the coupling portion (62). Connecting device according to claim 2 or 3, wherein the contact surface (82) of the coupling portion (62) of the lever member (54) and the contact surfaces (80) of the clamping portions (74a-d) abut each other and are mutually braced or braced. Connecting device according to one of the preceding claims, wherein the positioning element (68) is received without force transmission in the assembled state of the connecting device (50). Gas turbine (10), in particular an aircraft gas turbine with a plurality of circumferentially juxtaposed adjustable blades (51), in particular vanes, wherein on each blade a connecting device (50) is arranged according to one of the preceding claims, and wherein the lever elements (54) of the connecting means (50 ) are coupled to a along the circumferential direction of the gas turbine (10) movable adjusting ring (96).

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