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. 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 comprises 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. A compensation device is provided, via 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 for the purpose of maintaining these distances.

Claims

1. A guide vane assembly with 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, and wherein the adjusting appliance comprises 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, a compensation device is provided via 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, on the one hand, and of the housing, on the other, are at least partially compensated, and the compensation device defines a contact surface for the adjusting element and has a compensation element that is arranged between the adjusting element and the outer side of the housing and that is attached at the housing and, in the event of a thermal expansion in the circumferential direction, leads to a radial displacement of the contact surface for the adjusting element.

2. The guide vane assembly according to claim 1, wherein the compensation element has a higher thermal expansion coefficient than the housing.

3. The guide vane assembly according to claim 1, wherein the compensation device is constructed of at least two parts and, in addition to the compensation element, has a separate spacer element which is connected therewith and at which the contact surface is provided.

4. The guide vane assembly according to claim 3, wherein the spacer element and the compensation element are embodied and connected to each other in such a manner that, in the event of a temperature-related elongation of the compensation element along the circumferential direction, a radial distance between the compensation element and a section of the spacer element, at which the contact surface for the adjusting element is provided, changes.

5. The guide vane assembly according to claim 3, wherein the compensation element that is attached at the housing has a higher thermal expansion coefficient than the spacer element.

6. The guide vane assembly according to claim 3, wherein the spacer element is connected to the compensation element at least at two attachment locations that are arranged at a distance to each other in the circumferential direction.

7. The guide vane assembly according to claim 6, wherein the spacer element has at least two connecting arms for connecting to the compensation element, with a base body of the spacer element, which is arranged at a radial distance to the compensation element with respect to the central axis and at which the contact surface for the adjusting element is provided, extending in between

8. The guide assembly according to claim 7, wherein the spacer element is connected to the compensation element via four connecting arms that are arranged in pairs opposite each other at two side surfaces of the compensation element that are facing away from each other with respect to the central axis.

9. The guide vane assembly according to claim 7, wherein the spacer element and the compensation element are embodied and connected to each other in such a manner that the base body of the spacer element, two connecting arms of the spacer element and the compensation element extend along the edges of a virtual trapezoidal contour, as viewed along the central axis.

10. The guide vane assembly according to claim 9, wherein the compensation element extends along a base of the virtual trapezoidal contour, the base body extends along a basic side that is shorter as compared to the base of the virtual trapezoidal contour, and the two connecting arms extend along two legs of the virtual trapezoidal contour.

11. The guide vane assembly according to claim 9, wherein the virtual trapezoidal contour corresponds to the contour of an isosceles trapezoid.

12. The guide vane assembly according to claim 1, wherein the compensation element is embodied in a bar-shaped, tubular or sleeve-shaped manner.

13. The guide vane assembly according to claim 1, wherein the compensation element has a lower thermal expansion coefficient than the housing and/or forms the contact surface for the adjusting element.

14. The guide vane assembly according to claim 1, wherein the compensation element and a section of the housing at which it is attached extend along the edges of a virtual trapezoidal contour, wherein the section of the housing extends along an edge of a base of the trapezoidal contour, and two legs and a shorter basic side of the trapezoidal contour that is positioned opposite the base are defined by the compensation element.

15. The guide vane assembly according to claim 13, wherein the compensation element and a section of the housing at which it is attached extend along the edges of a virtual trapezoidal contour, wherein the section of the housing extends along an edge of a base of the trapezoidal contour, and two legs and a shorter basic side of the trapezoidal contour that is positioned opposite the base are defined by the compensation element.

16. The guide vane assembly according to claim 1, wherein the adjusting element is supported at the compensation device, and/or multiple compensation devices that are arranged at a distance to each other and respectively coupled with the housing are provided along the circumferential direction.

17. The guide vane assembly according to claim 1, wherein the adjusting element is embodied as a one-piece or multi-piece adjusting ring and/or is ring-segment-shaped or ring-shaped.

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

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The attached Figures illustrate possible embodiment variants of the solution according to the invention by way of example.

[0031] FIG. 1 shows, in sections, a first embodiment variant of a guide vane assembly according to the invention with a compensation device in multi-part design, comprising a compensation element and a spacer element that overlaps with the same radially outside at least partially.

[0032] FIGS. 2A-2B show exploded views of the compensation device of FIG. 1.

[0033] FIG. 3 shows a perspective detail drawing of the spacer element.

[0034] FIG. 4 shows a perspective detail drawing of the compensation element.

[0035] FIGS. 5A-5B show, in sections, a second embodiment variant of a guide vane assembly according to the invention with a single compensation element for defining a virtual trapezoidal contour.

[0036] FIG. 6 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.

[0037] FIG. 7 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

[0038] 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.

[0039] 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.

[0040] Here, FIG. 6 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.

[0041] 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.

[0042] 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 that 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. 1, 2A to 2B, 3, 4 and 5A to 5B.

[0043] FIGS. 1, 2A-2B, 3 and 4 illustrate, in a synoptic view, a first embodiment variant of a guide vane assembly according to the invention L in which a compensation device 4 is constructed in multi-part design and in particular with a longitudinally extending compensation element 40 and a spacer element 41 that is attached thereat. The compensation element 40 is designed in a sleeve-shaped manner with a rectangular cross-section and is attached at the housing 1 at which the guide vanes 111 are mounted in a rotatable manner.

[0044] Here, the connection to the housing 1 is realized at a radially protruding mounting socket 1140 of the outer shell-surface 114 of the housing 1. Provided at this mounting socket 1140 are attachment openings 1140a and 1140b that are arranged at a distance to each other along the circumferential direction U, for example in the form of bore holes. A positioning pin 7 is inserted into the attachment opening 1140a as a positioning element. By means of this positioning pin 7, at which the mounting socket 1140 radially protrudes and meshes into one of two attachment openings 401.1, 401.2 at a bottom side 40B of the compensation element 40 that is facing towards the shell-surface 114 in the mounted state, the compensation element 40 can be attached at the housing 1 in a manner secured against loss, before final affixing is carried out by means of a separate attachment element in the form of a threaded bolt 60. This threaded bolt 60 passes through a passage hole 410b at the spacer element 41 as well as two opposite passage holes 400b and 400c at a top side 40A and bottom side 40B of the compensation element 40. For affixing the compensation element 40 at the housing 1, the threaded bolt 60 is screwed into the attachment opening 1140b of the mounting sockets 1140. Here, the threaded bolt 60 also passes a spacer sleeve 62 that is positioned inside the hollow compensation element 40 and between the passage holes 400b and 400c.

[0045] The passage hole 410b in the spacer element 41 of the compensation device 4 is embodied centrally at a base body 410 of the spacer element 41. This base body 410 forms a contact surface 410a, at which the adjusting ring 30 can abut and is locally supportedpossibly by means of sliding elements that may be additionally attached thereatin the mounted state of the guide vane assembly L according to the intended use.

[0046] Here, the spacer element 41 is connected to the compensation element 40 and designed in such a manner that, in the event of a temperature-related elongation of the compensation element 40 along the circumferential direction U, a radial distance b between the compensation element 40 and the base body 410 of the spacer element 41, at which the contact surface 410a for the adjusting ring 30 is provided, changes. For this purpose, the longitudinally extending spacer element 41 acting as a spacer has connection sections that are supported in a flexible manner opposite the base body 410 by means of respectively two lateral notches or recesses 43.1, 43.4 or 43.2, 43.3 having respectively two connecting arms 42.1, 42.4 or 42.2, 42.3.

[0047] Each pair of connecting arms 42.1, 42.4 or 42.2, 42.3 is connected to the compensation element 40 in a rigid or articulated manner at a longitudinal end of the compensation elements 40 via respectively one attachment element, here e.g. in the form of a threaded bolt 50a or 50b. Here, in the connected state, the connection arms 42.1, 42.4 or 2.2,42.3 are present facing each other in pairs at two side surfaces 40C and 40D of the compensation element 40, and thus along a connection axis 50a or 50b behind each other, so that the compensation element 40 is located between the respective pair of connecting arms 42.1, 42.4 or 42.2, 42.3. The threaded bolts 50a, 50b for the attachment of the connecting arms 42.1-42.4 respectively extend through the openings at the connecting arms 42.1, 42.4 or 42.2, 42.3, on the one hand, and, on the other, through connection openings 402.1,402.4 or 402.2, 402.3 of the compensation element 40 that are aligned therewith. Nuts 51a, 51b are screwed on the threaded bolt 50a, 50b for fixation.

[0048] In the present case, the compensation element 40 has a lower thermal expansion coefficient than the housing 1 at which it is attached, and than the spacer element 41 at which the compensation element 40 is fixedly attached and is positioned with a base body 410 in the radial direction between the compensation element 40 and the adjusting ring 30. If the housing 1 expands in the radial direction during operation of the gas turbine engine T, this is accompanied by a stronger thermal expansion of the spacer element 40 along the circumferential direction U. In this temperature-related thermal expansion of the compensation element 40, the two pairs of connecting arms 42.1, 42.4 and 42.2, 42.3 of the spacer element 41 that are respectively fixedly attached at a longitudinal end of the spacer element 40, are displaced relative to each other. Here, the spacer element 41 and the compensation element 40 are embodied and connected to each other via the connecting arms 42.1-42.4 of the spacer element 41 in such a manner that the base body 410 of the spacer element 41, respectively two connecting arms 42.1, 42.2 or 42.3, 42.4 of the spacer element 41 that are arranged at a side surface 40C or 40D of the compensation element 40, and the compensation element 40 itself extend along the edges of a virtual trapezoidal contour TF, as viewed along the central axis M (cf. FIG. 1). In this way, the thermal expansion of the compensation element 40 and the accompanying relative displacement of the pairs of connecting arms 42.1, 42.4 and 42.2, 42.3 leads to a radial displacement of the base body 410 with the contact surface 410a relative to the compensation element 40, and thus in the radial direction relative to the outer shell surface 114 of the housing 1. This radial displacement of the contact surface 410a usually occurs counter to a radial expansion of the housing 1 and a radial expansion of the adjusting ring 30 (that is smaller by comparison). However, it principally depends on the (operational) cycle of the engine T. Consequently, in the event of a temperature-related thermal expansion of the housing 1 radially outwards, the radial distance b is reduced through the elongation of the trapezoidal contours TF along the circumferential direction U, and thus the contact surface 410a is moved closer to the shell-surface 114 of the housing 1. At that, the contact surface 410a for the adjusting ring 30 is displaced radially inwards, for example substantially by half the distance by which the housing 1 expands stronger radially outwards as compared to the adjusting ring 30 when the temperature is increased. Accordingly, different radial thermal expansions of the adjusting ring 30 and the housing 1 are at least partially compensated by the compensation device 4, and a centered position of the adjusting ring 30 to the housing 1 is maintained also during operation of the gas turbine engine T.

[0049] The degree of radial displaceability of the contact surface 410a for the adjusting ring 3 provided at the base body 410 can in particular be adjusted through the material thickness of the spacer element 41, which may for example be made of a (sheet) metal, the flexibility between the base body 41 and the connection sections of the spacer element 41 that respectively comprise a pair of connecting arms 42.1, 42.4 or 42.2, 42.3, and/or the degree of an angulation of the connecting arms 42.1-42.4 relative to the base body 41.

[0050] A further embodiment variant of a guide vane assembly L according to the invention, in which a compensation device 4 has only single spacer element 40, is illustrated in sections based on the sectional view of FIG. 5A and the top view of FIG. 5B. As shown in FIG. 5A, in the mounted state according to the intended use, the compensation element 40 defines a trapezoidal contour together with the section of the housing 1 at which the compensation element 40 is fixedly attached, as seen in a side view along the central axis M. At that, the compensation element 40, which extends longitudinally along the circumferential direction U and is for example made of a titanium alloy, has a length of l1 auf. Embodied between two attachment sections 406.1 and 406.2 of the compensation element 40 that are provided at the longitudinal end of the compensation element 40, is a section that projects radially outwards in an elevated manner and forms the contact surface 400a for the adjusting ring 30 at a top side 40A of the compensation element 40. This (middle) section of the compensation element 40 that is provided with the contact surface 400a has a smaller l2 (l2>l1), and is positioned at a radial distance b to the outer shell surface 114 of the housing 1 when the compensation element 40 is affixed at the housing 1 according to the intended use.

[0051] Here, the affixing realized via respectively one attachment element in the form of a threaded bolt 60.1 or 60.2. Each of these threaded bolts 60.1, 60.2 is guided through a passage hole in the associated attachment section 406.1 or 406.2 and screwed into a mounting socket 1140 of the housing 1 that is projecting at the shell-surface 114.

[0052] At the symmetrically designed compensation element 40, the middle section with the contact surface 400a is connected on both sides along the circumferential direction U to a respective attachment section 406.1 or 406.2 via respectively one lateral section. The lateral section of the compensation element 40 is angled at an angle a to the middle section in the direction of the housing 1. For example, the angle is in the range of 15 to 25, for example at approximately 20. When affixed at the housing 1 according to the intended use, the compensation element 40 defines a virtual trapezoidal contour TF together with the section of the housing 1 at which it is attached, with the section of the housing 1 extending along a base of the trapezoidal contour TF, and two legs as well as a shorter basic side of the trapezoidal contour TF that lies opposite the base are defined by the compensation element 40, namely by the middle section comprising the contact surface 400a and the two angled sections that laterally connect therewith

[0053] Besides, to be able to provide an additional sliding element for placement of the adjusting ring 30 at the contact surface 400a, through bores O1 and O2 are provided at the middle section of the compensation element 40. A corresponding sliding element can be attached thereat to provide it at the contact surface 400a.

PARTS LIST

[0054] 1 housing

[0055] 10 bearing extension

[0056] 11 low-pressure compressor

[0057] 110 rotor blade

[0058] 111 guide vane

[0059] 111a bearing journal

[0060] 111b journal end

[0061] 114 shell surface

[0062] 1140 mounting socket

[0063] 1140a, 1140b attachment opening

[0064] 12 high-pressure compressor

[0065] 12a-12d rotor blade row

[0066] 13 high-pressure turbine

[0067] 13a-13c guide vane row

[0068] 14 medium-pressure turbine

[0069] 15 low-pressure turbine

[0070] 3 adjusting appliance

[0071] 30 adjusting ring (adjusting element)

[0072] 31 adjustment lever

[0073] 4, 4 compensation device

[0074] 40, 40 compensation element

[0075] 400a contact surface

[0076] 400b, 400c passage hole

[0077] 401.1, 401.2 bearing opening

[0078] 402.1-402.4 connection opening

[0079] 406.1, 406.2 attachment sectiont

[0080] 40A top side

[0081] 40B bottom side

[0082] 40C, 40D side surface

[0083] 41 spacer element

[0084] 410 base body

[0085] 410a contact surface

[0086] 410b passage hole

[0087] 42.1-42.4 connecting arm

[0088] 43.1-43.4 notch/recess

[0089] 50a, 50b threaded bolt (attachment element)

[0090] 51a, 51b nut

[0091] 5a, 5b connection axis

[0092] 60 threaded bolt (attachment element)

[0093] 60.1, 60.2 threaded bolt (attachment element)

[0094] 62 spacer sleeve

[0095] 7 positioning pin (positioning element)

[0096] A outlet

[0097] a distance

[0098] B by-pass channel

[0099] b distance

[0100] BK combustion chamber section

[0101] D rotational axis/spindle axis

[0102] E inlet/intake

[0103] F fan

[0104] L guide vane assembly

[0105] l1,l2 length

[0106] M central axis/rotational axis

[0107] O1, O2 through bore

[0108] R entry direction

[0109] T gas turbine engine

[0110] TT turbine

[0111] U circumferential direction

[0112] V compressor

[0113] angle