Guide vane assembly with compensation device

Abstract

A guide vane assembly with at least one guide vane row and a housing for the at least one guide vane row that extends along a circumferential direction about a central axis, wherein the at least one guide vane row includes multiple guide vanes that are respectively mounted at the housing in an adjustable manner by means of an adjusting appliance of the guide vane assembly. The adjusting appliance includes at least one adjusting element for adjusting the guide vanes that is arranged at a radial distance to an outer side of the housing with respect to the central axis, and a compensation device is provided, by means of which a radial distance of the adjusting element to the outer side of the housing is predetermined, and the different thermal expansions of the adjusting element and of the housing are at least partially compensated.

Claims

1. A guide vane assembly comprising: at least one guide vane row and a housing for the at least one guide vane row extending along a circumferential direction about a central axis, wherein the at least one guide vane row comprises multiple guide vanes that are respectively mounted at the housing in an adjustable manner by means of an adjusting appliance of the guide vane assembly, the adjusting appliance including an adjusting element for adjusting the multiple guide vanes that is arranged at a radial distance to an outer side of the housing with respect to the central axis, a compensation device by which a radial distance of the adjusting element to the outer side of the housing is predetermined, and different thermal expansions of the adjusting element, on one hand, and of the housing, on the other hand, are at least partially compensated, the compensation device including a compensation element arranged between the adjusting element and the outer side of the housing and connected to the adjusting element via at least one connection element of the compensation device that is hinged at the adjusting element, wherein the at least one connection element is also hinged at the compensation element, and wherein the compensation element has a higher thermal expansion coefficient than the at least one connection element.

2. The guide vane assembly according to claim 1, wherein the at least one connection element includes a lever hinged with a lever end at the adjusting element.

3. The guide vane assembly according to claim 1, wherein the compensation element is coupled to the at least one connection element and connected via the at least one connection element to the adjusting element such that, in an event of a temperature-related expansion of the compensation element along the circumferential direction, a radial distance between the compensation element and the adjusting element is changed.

4. The guide vane assembly according to claim 1, wherein the at least one connection element includes two connection elements hinged at the adjusting element at positions that are arranged at a distance to each other along the circumferential direction, and respectively connected to the compensation element.

5. The guide vane assembly according to claim 4, wherein the two connection elements are connected to the adjusting element and the compensation element such that at a section of the adjusting element at which the two connection elements are hinged, the two connection elements and the compensation element extend along edges of a virtual trapezoidal contour, as viewed along a central axis.

6. The guide vane assembly according to claim 5, wherein the compensation element extends along a base of the virtual trapezoidal contour and the two connection elements extend along two legs of the virtual trapezoidal contour.

7. The guide vane assembly according to claim 5, wherein the virtual trapezoidal contour corresponds to a contour of an isosceles trapezoid.

8. The guide vane assembly according to claim 4, wherein the at least one connection element includes four connection elements and the compensation element is connected to the adjusting element via the four connection elements, which are respectively hinged at the adjusting element and arranged in pairs opposite each other at two sides of the adjusting element that are facing away from each other with respect to the central axis.

9. The guide vane assembly according to claim 1, wherein the adjusting element is supported at the outer side of the housing via the compensation device.

10. The guide vane assembly according to claim 1, and further comprising a plurality of the compensation device arranged at a distance to each other along the circumferential direction and respectively coupled to the adjusting element.

11. The guide vane assembly according to claim 1, and further comprising at least one separate sliding element, which has a sliding surface for abutment at the outer side of the housing, the at least one separate sliding element being at least one chosen from attached at the compensation element and inserted with a fastening section into a bore hole of the compensation element.

12. The guide vane assembly according to claim 1, wherein the adjusting element is embodied as at least one chosen from a single-piece adjusting ring, a multi-piece adjusting ring, ring-segment-shaped and ring-shaped.

13. The guide vane assembly according to claim 1, and further comprising at least one chosen from 1) wherein the compensation element is made at least partially of magnesium and 2) the at least one connection element is made at least partially of titanium or titanium alloy.

14. An engine with at least one guide vane assembly according claim 1.

15. A guide vane assembly comprising: at least one guide vane row and a housing for the at least one guide vane row extending along a circumferential direction about a central axis, wherein the at least one guide vane row comprises multiple guide vanes that are respectively mounted at the housing in an adjustable manner by an adjusting appliance of the guide vane assembly, the adjusting appliance including an adjusting element for adjusting the multiple guide vanes that is arranged at a radial distance to an outer side of the housing with respect to the central axis, a compensation device, by which a radial distance of the adjusting element to the outer side of the housing is predetermined, and different thermal expansions of the adjusting element, on one hand, and of the housing, on the other, are at least partially compensated, the compensation device including a compensation element arranged between the adjusting element and the outer side of the housing and connected to the adjusting element via at least one connection element of the compensation device that is hinged at the adjusting element, wherein the at least one connection element is hinged at the compensation element, wherein at least two connection elements are hinged at the adjusting element at positions that are arranged at a distance to each other along the circumferential direction, being respectively connected to the compensation element.

16. The guide vane assembly according to claim 15, wherein the at least two connection elements are connected to the adjusting element and the compensation element in such a manner that a section of the adjusting element at which two connection elements are hinged, these two connection elements and the compensation element extend along the edges of a virtual trapezoidal contour, as viewed along a central axis.

17. The guide vane assembly according to claim 16, wherein the compensation element extends along a base of the virtual trapezoidal contour and the two connection elements extend along two legs of the virtual trapezoidal contour.

18. The guide vane assembly according to claim 16, wherein the virtual trapezoidal contour corresponds to the contour of an isosceles trapezoid.

19. The guide vane assembly according to claim 15, wherein the compensation element is connected to the adjusting element via four connection elements, which are respectively hinged at the adjusting element and arranged in pairs opposite each other at two sides of the adjusting elements that are facing away from each other with respect to the central axis.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The attached Figures illustrate possible embodiment variants of the solution according to the invention by way of example.

(2) FIGS. 1A-1D show, in different views and respectively in sections, a compensation device of an embodiment variant of a guide vane assembly according to the invention with an adjusting element for adjusting the guide vanes of a guide vane row.

(3) FIGS. 2A-2B show different perspective views of the embodiment variant of a guide vane assembly according to the invention, with the adjusting element and the compensation device being in a state in which they are mounted at the housing of the guide vane assembly (with the guide vanes not being illustrated).

(4) FIG. 3A shows, in sections and in an enlarged sectional view, a compensation element of the compensation device with a sliding element for abutment at an outer side of the housing being attached thereat.

(5) FIG. 3B shows, in a perspective view, the sliding element of FIG. 3A in a detail drawing.

(6) FIG. 4 shows, in sections and in a perspective view, an arrangement as it is known from the state of the art with multiple guide vane assemblies with respectively one guide vane row and multiple rotor blade assemblies.

(7) FIG. 5 shows, in sectional view and in a schematic manner, a gas turbine engine in which at least one guide vane assembly according to the invention is used.

DETAILED DESCRIPTION

(8) FIG. 7 schematically illustrates, in a sectional rendering, a (gas) turbine engine T in which the individual engine components are arranged in succession along a central axis or rotational axis M. By means of a fan F, air is suctioned in along an entry direction E at an inlet or an intake E of the engine T. This fan F is driven via a shaft that is set into rotation by a turbine TT. Here, the turbine TT connects to a compressor V, which for example has a low-pressure compressor 11 and a high-pressure compressor 12, and where necessary also a medium-pressure compressor. The fan F supplies air to the compressor V, on the one hand, and, on the other hand, to a by-pass channel B for generating a thrust. The air that is conveyed via the compressor V is transported into the combustion chamber section BK where the driving power for driving the turbine TT is generated. For this purpose, the turbine TT has a high-pressure turbine 13, a medium-pressure turbine 14, and a low-pressure turbine 15. The turbine TT drives the fan F by means of the energy that is released during combustion in order to generate the necessary thrust by means of the air that is conveyed into the bypass channel B. The air is discharged from the bypass channel B in the area of an outlet A at the end of the engine T, where exhaust from the turbine TT flows outwards. Here, the outlet A usually has a thrust nozzle.

(9) The compressor V comprises multiple rows of rotor blades 110 that are arranged behind each other in the radial direction, as well as rows of guide vanes 111 arranged in between them in the area of the low-pressure compressor 11. The rows of rotor blades 110 rotating about the central axis M and the rows of stationary guide vanes 111 are arranged alternatingly along the central axis M and accommodated inside a (compressor) housing 1 of the compressor V. The individual guide vanes 111 are mounted at the single-part or multi-part housing 1 in an adjustable mannerusually in addition to a radially inner bearing at the hub of the compressor V.

(10) Here, FIG. 4 shows, in sections and in greater detail, an arrangement of rotor blade rows 12a to 12d and guide vane rows 13a to 13c for the low-pressure compressor 11 as it is known from the state of the art. The guide vanes 111 of the guide vane rows 13a, 13b and 13c that are arranged behind each other are mounted at the housing 1 in an adjustable manner so that the position of the guide vanes 111 can be changed depending on the compressor's rotational speed. For this purpose, a bearing journal 111a of each rotor blade 111 is mounted in a rotatable manner in a bearing opening that is embodied by a sleeve-shaped and radially outwardly protruding bearing extension 10 of the housing 1. Each bearing journal 111a is mounted and supported inside an associated bearing extension 10 so as to be rotatable about a rotational axis D. At that, each bearing journal 111a passes through an associated bearing extension 10, so that a journal end 111b projects from the bearing extension 10 at the outer side of the housing 1.

(11) Thus, respectively one adjustment lever 31 of an adjusting appliance 3 can engage at the individual journal ends 111b to rotate the bearing journal 111a, and thus change the position of the associated guide vane 111. Here, the levers 31 of a guide vane row 13a, 13b or 13c are respectively hinged at an adjusting element in the form of an adjusting ring 30 of the adjusting appliance 3. The adjusting ring 30, which is often comprised of multiple parts and divided into at least two segments, extends at the circumferential side along the outer shell surface of the housing 1. Thus, by adjusting the adjusting ring 30, the adjustment lever 31 hinged thereat as well as multiple, usually all, guide vanes 111 of a guide vane row 13a, 13b or 13c can be adjusted. At that, the individual adjusting rings 30 for the individual guide vane rows 13a, 13b and 13c are usually adjustable independently of each other.

(12) An adjusting ring 30 is supported at an outer side of the housing 1, for example at a contact surface 114 that extends at the circumferential side. Here, the adjusting ring 30 is arranged at a radial distance a to the outer side of the housing 1, and in the present case to the contact surface 114, in the radial direction. This radial distance is predetermined by multiple compensation devices which are arranged in a distributed manner along the circumference and via which the adjusting ring 30 is supported at the outer side of the housing 1, and is to hold the adjusting ring 30 in a centered position with respect to the housing 1. However, during operation of the gas turbine engine T, there is the difficulty that, due to the temperature, the housing 1 expands stronger radially outwards than the adjusting ring 30, depending on the respective (operational) cycle of the engine T. Thus, inaccuracies in the adjustment of the guide vanes 111 by means of the adjusting ring 30 or even a jamming or deformation of the adjusting ring 30 may occur. The solution according to the invention aims at remedying this problem, with possible embodiment variants being illustrated in more detail based on FIGS. 1A to 1D, 2A to 2B, and 3A to 3B.

(13) Accordingly, a compensation device 4 with a longitudinally extending, rod-shaped compensation element 40 is provided. Via the compensation device 4, different thermal expansions of the adjusting ring 30, on the one hand, and of the housing 1, on the other, are compensated by providing a compensation element 40 that is connected to the adjusting ring 30 in such a manner via multiple connection levers 41-44 (with a lower thermal expansion coefficient) hinged at the adjusting ring 30 that the compensation element 40 can be radially displaced by a temperature-related expansion (thermal expansion or contraction) relative to the adjusting ring 30. For this purpose, the compensation element 40, which in the present case is embodied in the manner of a (flat) bar, has a higher thermal expansion coefficient than the connection levers 41-44, via which the compensation element 40 is supported in a radially displaceable manner at the adjusting ring 30 between the adjusting ring 30 and the outer side of the housing 1. Further, temperature compensation is supported by the connection levers 41-44 being embodied to be shorter and slimmer than the compensation element 40, and by the compensation element 40 being arranged closer to the housing 1 (as compared to the connection levers 41-44). Thus, the temperature-related expansion has less of an impact on the connection levers 41-44 than on the compensation element 40 during operation of the engine T.

(14) Each of the presently four connection levers 41-44 is hinged at the adjusting ring 30 at a lever end via a first hinged connection 413, 423, 433 or 443, and at its other lever end is hinged at the compensation element 40 via a second hinged connection 410, 420, 430 or 440. The connection levers 41-44 are arranged in pairs opposite each other at the two face sides 30A and 30B of the adjusting ring, and support the compensation element 40 radially with respect to a bottom side 30C of the adjusting ring 30, which is facing towards one of the outer sides of the housing 1, and is radially displaceable between the adjusting ring 30 and the outer side of the housing 1. Here, the connection of the connection levers 40-44 to the compensation element 40 is respectively realized in the area of a longitudinal end of the longitudinally extending compensation element 4. At that, the connection levers 41-44 are arranged at first and second face sides 30A and 30B of the adjusting ring 30 that are facing away from each other, with the adjusting ring 30 having a rectangular cross-section in the present case. Here, the first face side 30A forms a front face side, while the second face side 30B forms a back or rear face side of the adjusting ring 30 in the mounted state of a guide vane assembly L, which in particular comprises the adjusting ring 30 and the compensation device 4, according to the intended use.

(15) The adjusting ring 3 can be supported against the housing 1 via the compensation element 40. For this purpose, the compensation element can abut with its bottom side at the abutment surface 114 of the housing 1, as it is illustrated in the perspective renderings of FIGS. 2A and 2B.

(16) Viewed in an axial direction along the central axis M, the compensation element 4 extends along a virtual trapezoidal contour TF together with two connection levers 41, 42 or 43, 44 that are hinged at the first or second face side 30A or 30B, and a section of the adjusting ring 3 at which the first hinged connections 413, 423 (433, 443) are defined. Here, the compensation element 40 extends in the circumferential direction U at a longer basis side or base of this trapezoidal contour TF, while the two facing connection levers 41, 42 or 43, 44 of a face side 30A or 30B extend along two legs of this trapezoidal contour TF. The shorter basis side of the trapezoidal contour TF is formed by a section of the adjusting ring 30. Through this trapezoidal arrangement and linkage of the connection levers 41-44, it is achieved that, in the event of a temperature-related thermal expansion, the compensation element 40 is displaced relative to the bottom side 30C of the adjusting ring 30, and thus a radial distance b (cf. FIG. 10) of the compensation element 40 to the bottom side 30C of the adjusting ring 30 can change as a result of the thermal expansion of the compensation element 40.

(17) If, for example, the compensation element 40 extends along the circumferential direction U, the facing connection levers 41, 42 and 43, 44 of a face side 30A or 30B are pivoted into opposing pivoting directions, as the lever ends connected to the compensation element 40 are put at a greater distance to each other. The virtual trapezoidal contour TF is thus compressed. The compensation element 40 is moved closer to the bottom side 30C of the adjusting ring 30. Conversely, if the compensation element 40 cools off, the connection levers 41, 42 or 43, 44 associated with a face side 30A or 30B respectively pivot towards each other with their ends that are connected to the compensation element 40. The virtual trapezoidal contour TF is elongated. The compensation element 40 is thus displaced radially inward away from the bottom side 30C of the adjusting ring 30. In this manner, the compensation device 4 compensates a temperature-related expansion of the housing 1 radially outward with respect to the adjusting ring 30 that expands radially outward to a lesser degree as a result of the temperature, and substantially maintains a radial distance of the compensation element 40 to the abutment surface 114 of the housing 1. This in particular includes a radial distance of 0 cm, and thus a direct abutment of the compensation element 40, via its abutment surface, at the housing 1, with the compensation element 40 abutting at the outer side of the housing 1 and the adjusting ring 30 being supported in this manner in the radial direction with respect to the central axis M. Through the temperature-related radial displacement of the compensation element 40 relative to the adjusting ring 3, it is ensured that the adjusting ring 3 is not locally displaced or at most only minimally displaced in certain sections by the radially outward expanding housing 1. Instead, the adjusting ring 30 is supported in a centered position with respect to the housing 1.

(18) In order to not obstruct a temperature-related elongation or contraction of the compensation element 40 along the circumferential direction U by a possible frictionally engaged contact even during abutment at the abutment surface 114 of the housing 1, and also to be able to readily displace the compensation element 40 at the abutment surface 114 along the circumferential direction U when the guide vanes 111 are to be adjusted via the adjusting ring 30, at least one separate sliding element 5 can be attached at the compensation element 40. In the present case, a sliding element 5 is embodied in the kind of a plug and inserted into bore holes 401 of the compensation element 40 that are arranged at a distance to each other along the circumferential direction U, so that a disc-shaped head forming a sliding or contact surface 50 projects at the bottom side of the compensation element 40 from the respective bore hole 401. The compensation element 40 abuts at the abutment surface 114 of the housing 1 via this sliding or contact surface 50. Here, each sliding element 5 is inserted via a fastening section 51 into the respective bore hole 401 of the compensation element 4, and is affixed therein via snap-in lamella 510 in the respective bore hole 401, with the snap-in lamella 510 projecting radially with respect to a longitudinal axis of the journal. This is illustrated based on the enlarged rendering of FIGS. 3A and 3B. In contrast to providing at least one sliding element that can be inserted into a bore hole, a corresponding sliding/contact surface 50 at the bottom side of the compensation element 40 can of course also be formed by one sliding element that is affixed at the compensation element 40, for example by means of bonding.

(19) By arranging the compensation device 4 at the adjusting ring 30 that is adjustable along the circumferential direction U, and thus connecting the radially displaceable compensation element 40, which abuts on the outer side of the housing 1 and against which the adjusting ring 30 is supported at the housing 1, to the adjusting ring 30, an integration of the compensation device 4 at a guide vane assembly L is possible without or with only minor constructional changes to the housing 1. The individual components of the compensation device 4 only have to be affixed at the adjusting ring. To ensure a centering of the adjusting ring 30 with respect to the housing 1 by means of multiple compensation devices 4 also during operation of the gas turbine engine T, for example at least three compensation devices 4 that are offset by 120 with respect to one another along the circumferential direction U, four compensation devices 4 that are respectively offset by 90 with respect to one another, or five compensation devices 4 that are respectively offset by 72 with respect to one another are provided at the adjusting ring 30. However, in principle any other number of compensation devices 4 that are arranged so as to be distributed along the circumferential direction U at the adjusting ring 30 can be provided.

PARTS LIST

(20) 1 housing 10 bearing extension 11 low-pressure compressor 110 rotor blade 111 guide vane 111a bearing journal 111b journal end 114 abutment surface 12 high-pressure compressor 12a-12d rotor blade row 13 high-pressure turbine 13a-13c guide vane row 14 medium-pressure turbine 15 low-pressure turbine 3 adjusting appliance 30 adjusting ring (adjusting element) 30A, 30B 1.sup.st/2.sup.nd face side 30C bottom side 31 adjustment lever 4 compensation device 40 compensation element 401 bore hole 41, 42, 43, 44 connection lever (connection element) 410, 420, 430, 440 (second) hinged connection 413, 423, 433, 443 (first) hinged connection 5 sliding element 50 sliding/contact surface 51 fastening section 510 snap-in lamellas A outlet A distance B bypass channel B distance BK combustion chamber section D rotational axis/spindle axis E inlet/intake F fan L guide vane assembly M central axis/rotational axis R entry direction T gas turbine engine TF trapezoidal contour TT turbine U circumferential direction V compressor