EP3246529B1 - Guide vane, corresponding guide vane ring and assembly method - Google Patents

Description

The invention relates to a guide vane for a vane ring of a turbomachine, a vane ring for a turbomachine and a method for mounting a vane ring.

Turbomachines such as aircraft engines and stationary gas turbines often have at least one compressor-side guide vane row with a plurality of guide vanes for setting optimum operating conditions. The vane row forms an inner ring with a so-called vane ring. Preferably, the guide vanes are pivotable about their longitudinal axis.

A radially outer bearing of the vanes on a housing or housing part and a pivoting of the vanes can be done on outer vanes on the vanes and possibly adjoining adjustment pins that are used in associated receptacles of the housing and cooperate with a corresponding adjustment on the outer housing can.

The inner ring preferably has a plurality of receptacles extending in the radial direction, in each of which a guide plate of a guide vane is or can be inserted. Such an (inner) stator blade serves to stabilize or a radially inner bearing of the guide vanes; The terms "radial" and "axial" refer in this document - unless otherwise stated - always on a central geometric axis of the inner ring, which is not always specially formulated for readability. At the side opposite the vane, a vane plate may have a journal, and the receptacle may be configured to receive the trunnion together with a mating sleeve. On the inner ring, a seal carrier is preferably guided, which is provided with sealing elements or Einlaufbelegen, facing the rotor-side sealing ribs.

The assembly of the vanes on the inner ring is usually carried out after the outer stator blade and associated adjustment pins of the vanes are pre-assembled on the housing. Thus, the inner stator blade can be used or threaded in this position in the receptacles of the inner ring, there is for the design of the inner ring various concepts: In particular, the inner ring may comprise two part rings to be assembled in the axial direction and / or divided into ring segments.

In the axial direction zusammenzusetzende partial rings are disadvantageous in terms of the stability of the inner ring. Due to the over the circumference of the inner ring extending parting line they also affect a precise positioning of sealing elements or inlet linings and promote leakage.

Often therefore undivided, so-called "integral" inner rings are preferred in the axial direction, forming the monolithic enclosures of the individual recordings. Such inner rings may be divided into two or more ring segments; it is advantageous, e.g. a division into two half rings.

Suitably shaped inner guide blade plates thereby enable or simplify threading of the respective guide blades into such an inner ring. In particular, from the document DE 10 2009 004 933 A1 a vane with an inner vane plate known, on the peripheral side of a chamfer is formed; this allows for the insertion of the guide plate in a circular cylindrical recording a slight inclination of the vane relative to the inner ring, which can be stretched for threading and thereby temporarily curved beyond its normal shape going out.

However, such a chamfer also requires a relatively large cavity between an inserted guide blade plate and a wall of the receptacle; Such a cavity, in turn, may favor disadvantageous leakage, especially in unfavorable storage positions of the guide vane.

US 2010/232936 A1 shows an adjustable vane with an airfoil and a blade plate and a pin, both of which are provided for receiving in an inner ring. The blade plate with a cover surface facing the blade leaf and a base surface facing away from the blade leaf in this case has an edge surface with a completely circumferential bevel on its base.

US 2013/195651 A1 describes an adjustable vane with a provided for use in a receptacle of an inner ring paddle and blade pin. The blade plate has a top surface with a surface adapted to the annular space and a substantially straight running surface facing away from the flow channel. At the base there is arranged a small chamfer which completely revolves with respect to the total area of the base.

EP 2 696 041 A1 relates to a vane with a blade plate and a blade pin, which serve for receiving in a socket in an inner ring. In the schematic representation of the blade plate on its top surface on a slope which forms part of the annular space.

US 2004/109762 A1 relates to a vane with a blade plate and a blade pin, which serve for receiving in an inner ring. The blade plate has on its top surface a slope which forms part of the annular space.

The present invention has for its object to provide a technique that allows easy mounting of a vane ring while minimizing leakage susceptibility.

The object is achieved by a vane according to claim 1, a vane ring according to claim 5 and a method according to claim 7. Advantageous embodiments are disclosed in the subclaims, the figures and the description.

A guide vane according to the invention for a vane ring of a turbomachine comprises an airfoil and a stator vane, with which the vane can be mounted on an inner ring (preferably pivotably). The guide plate has a top surface facing the airfoil, a base surface opposite the top surface, and an edge surface connecting the top surface and the bottom surface. In a first region, the edge surface forms a chamfer of the stator blade, whereas in a second region it extends along (a portion) of a cylinder jacket surface. The first region of the edge surface is bounded by a different sector of the guide plate than the second region; During one revolution of the guide disk disk along the guide blade disk edge (or the edge surface), the first and second regions are thus successively passed. In particular, the guide blade plate is thus rotationally asymmetrically shaped (relative to a longitudinal axis of the guide blade).

The edge surface may e.g. be smooth (ie edge-free) be formed or composed of two or more surfaces that can be separated from each other by at least one edge.

The chamfer is preferably formed so that the guide blade plate tapers from the top surface to the base surface; In particular, the base surface is preferably smaller than the top surface. According to a preferred embodiment, the top surface and edge surface abut each other at an edge formed as an ellipse or (even) as a circle.

The bevel caused by the chamfer allows insertion of the vane in the inclined state in an associated receptacle in the inner ring; this preferably has a size suitable for the top surface of the vane ring (so that after insertion of the vane plate between its top surface and a radially outer surface of the inner ring, preferably a gap of at most 0.5 mm, more preferably at most 0.3 mm width occurs). The receptacle is preferably circular-cylindrical or formed as a section of a straight circular cylinder.

Due to the respective chamfer, the guide blade plates can also be sunk into a plurality of (with respect to the inner ring) radially arranged and preassembled on the outer housing guide vanes in the respective receptacles, because can be dispensed with an exactly vertical insertion. Nevertheless, according to the invention, the leakage between the receptacle and the inserted guide plate is kept low because the bevel is formed only in a portion of the circumference of the guide plate (which is referred to in this document as a "first" area): In another sub-area (here " second "area is called) runs the edge surface along the lateral surface of a cylinder, preferably a straight circular cylinder. In the direction parallel to the longitudinal axis of the vane, the second region preferably extends from the top surface to the bottom surface. In particular, the edge surface of a stator blade of a guide blade according to the invention in the second region preferably comprises straight line sections which run parallel to the longitudinal axis of the guide blade, for example the edge surface may be perpendicular to the base surface in the second region. This second area is set up after the onset of the Guide plate in a receptacle of an inner ring (which may have been made, for example, by means of a bore) to be adapted to its (a cylindrical surface forming) wall, which minimizes the leakage in this area.

An inventive vane ring comprises an inner ring and at least one guide vane according to the invention according to one of the embodiments disclosed in this document. In this case, the inner ring is preferably integral, that is to say has a plurality of receptacles for one guide plate each of which is formed (for example as a bore) in a monolithic component. The inner ring may comprise two or more ring segments.

According to an advantageous embodiment of a guide vane ring according to the invention, the edge surface of the at least one guide blade in the second region nestles flat against a wall of the associated receptacle; In this document, a "flat nestling" is understood as meaning a substantially conformal course of the surfaces in contact with one another or at a distance of at most 0.5 mm, more preferably at most 0.3 mm.

An inventive method is used to mount a vane ring. It comprises insertion (or threading) of a plurality of (preferably similar) guide vanes according to the invention into respective receptacles in an inner ring. The vanes are each formed according to one of the embodiments disclosed in this document. When inserting the vanes and the respective receptacles are temporarily inclined relative to each other, so that the base (on the side facing away from the airfoil) associated Leitschaufeltellers is temporarily inclined to a (the recording radially inwardly limiting) bottom surface of the receptacle. The tilting can be done by locally deforming the inner ring or by deflecting the respective pre-assembled in the housing vane.

According to an advantageous embodiment, the first region of the edge surface of the respective guide plate (which has a chamfer) projects further into the receptacle in the inclined position (radially) than the second region formed along a cylindrical surface; Alternatively, conversely, the second region of the edge surface may protrude further into the receptacle than the first region.

The threading or insertion thus preferably comprises a chamfer in which an edge between the base surface of the guide plate and the edge surface in the first (alternatively: in the second) area is lowered into the receptacle, while (at the same time) an (eg opposite) edge between the top surface and the edge surface in the second (alternatively: in the first) area outside (or above) of the receptacle protrudes beyond the radially outer inner ring surface. By means of a rotational movement of the receptacle and the vane against each other, the base surface of the vane plate can then be placed flat on a bottom surface of the receptacle and thus the insertion process can be completed.

A particularly efficient implementation makes possible an embodiment in which all the guide vanes are inclined one after the other or simultaneously identically and / or in the same way with respect to their respective receptacle.

According to an advantageous embodiment of the present invention, the edge surface in the first region has a circulation angle which lies in an interval of 20 ° to 170 ° (ie is at least 20 ° and at most 170 °). In this case, the "angle of rotation" is the angle through which the edge surface (in relation to the inner ring to be radially arranged or arranged) longitudinal axis of the guide vane in a cross section (orthogonal to the longitudinal axis) rotates. A circulation angle in such a range allows on the one hand a simple insertion of the guide plate into a corresponding receptacle, on the other hand is reduced by the upper barrier for the circulation angle disadvantageous leakage.

In the second region, the edge surface preferably has a circumferential angle of at least 180 ° (defined analogously to above). The second region of the edge surface thus comprises a circular arc which has an angle of at least 180 ° as the center angle. The edge surface of at least one half of the guide plate thus extends along a cylindrical surface, which in the mounted state allows a slight leakage between an associated (also cylindrically shaped) receptacle in the inner ring.

According to an advantageous embodiment, the top surface of the vane plate has a diameter which is greater than a (mean) thickness of the vane plate, ie as a (mean) extension of the vane plate in the direction of the longitudinal axis of the vane (Eg, a length of a running in the stator blade between the top and bottom surface portion of the longitudinal axis of the vane).

On the side facing away from the blade of the guide blade plate (at the base surface) may be arranged in the longitudinal direction of the guide blade extending journal. Such a journal is preferably formed substantially as a straight circular cylinder whose base has a diameter which is smaller than the diameter of the top surface of the guide plate. Particularly preferred is an embodiment in which the diameter of the base of the circular cylindrical shaped journal is smaller than its height, preferably at most 2/3 of the height. Thus, a particularly stable bearing of the guide vane can be achieved in a corresponding receptacle of the inner ring.

In the following preferred embodiments of the invention will be explained in more detail with reference to drawings. It is understood that individual elements and components can be combined differently than shown. Reference numerals for corresponding elements are used across figures and may not be rewritten for each figure.

Figur 1:

einen Teil einer Leitschaufel mit einem erfindungsgemäßen inneren Leitschaufelteller und

Figur 2:

eine erfindungsgemäße Leitschaufel, betrachtet vom inneren Leitschaufelteller in Richtung einer Längsachse einer Leitschaufel.

They show schematically:

FIG. 1:

a portion of a vane with an inner vane plate according to the invention and

FIG. 2:

a guide vane according to the invention, viewed from the inner stator blade in the direction of a longitudinal axis of a vane.

In FIG. 1 is a perspective view of a portion of a vane 10 is shown, which is pivotally mounted about a longitudinal axis A in a receptacle 21 of an (shown only in one section) inner ring 20. For better understanding, an insight into the receptacle 21 is shown in the illustration; the receptacle is designed as a straight circular cylinder, its central axis extends in the radial direction (of the inner ring) in the inner ring.

The vane 10 has an airfoil 11 and a stator blade 12. The vane plate 12 has a diameter D and an average thickness (or height) H (as Length of the section of the longitudinal axis A) running in the guide plate between the top and bottom surfaces, which is smaller than the diameter. The guide plate also has a blade 11 facing the top surface 14, one in the FIG. 1 concealed base surface and an edge surface 15 connecting the cover surface and the base surface. In the example shown, the cover surface and the base surface are inclined relative to one another; in alternative embodiments, these surfaces may lie parallel to one another.

In a first region B ₁ , the edge surface 15 forms a chamfer 16, in which the guide blade plate tapers in the direction of the base surface. The chamfer 16 allows during insertion of the guide plate into the receptacle 21, a tendency of the guide vane relative to the receptacle 21 in the inner ring 20 in the direction of the area B ₁ . This simplifies the threading of the pre-assembled in the outer housing vane in the receptacle 21st

Due to the chamfer 17 occurs between an inner wall of the receptacle 21 and the edge surface 15 in the area B _1, however, a cavity 30, which favors a leak. To keep this leakage low, the guide plate is formed so that the edge region extends in a second region B ₂ along a cylindrical surface. It nestles against the correspondingly shaped wall of the receptacle 21, so that a gap and thus leakage in this area is minimized.

The FIG. 2 shows an alternative vane 10 'having an airfoil 11 and a stator blade 12. The guide blade plate has on its side facing away from the blade 11 a base surface 17, and the FIG. 2 shows the vane 10 'in a perspective of the base 17 in the direction of a longitudinal axis of the vane 10' (relative to an inner ring in which the vane is to be inserted, ie radially outward). An edge surface 16, which connects the base surface 17 and the top surface of the stator blade together, forms in a first region B ₁ a chamfer, through which the stator blade 12 tapers in the direction of the base 17. In a second region B _2, however, the edge surface 15 extends along a cylindrical surface. As a result, a leakage can be kept low after insertion of the guide plate into a correspondingly cylindrical receiving an inner ring.

The first region B ₁ and the second region B ₂ bound each other different sectors of the guide plate 12 in the first area B ₁ , the edge surface has a circumferential angle α, which is smaller than 180 °; in the second region B _2, however, the edge surface has a circulation angle β, which is greater than 180 °, wherein β = 360 ° -α in the example shown.

The vane 10 'has on the base surface 17 of the guide plate on a bearing journal 13 which extends cylindrically in the direction of a longitudinal axis of the guide vane; in the

FIG. 2 Due to the perspective, only one base of the journal can be seen. Their diameter d is smaller than the diameter D of the guide plate 12th

A guide blade 10, 10 'for a guide vane ring of a turbomachine has an airfoil and, for its storage on an inner ring 20, a stator blade 12. In a first region B ₁ , the edge surface forms a chamfer 16 of the guide blade plate, and in a second region B, the guide blade plate has a cover surface 14 facing the airfoil, a base surface 17 opposite the cover surface and an edge surface 15 connecting the cover surface ₂ , which borders a different sector of the guide plate than the first region B ₂ , the edge surface extends along a cylindrical surface.

One method is for mounting a vane ring. It comprises inserting a plurality of guide vanes 10, 10 'in respective seats 21 in an inner ring 20. The guide vanes are each temporarily brought into a position inclined to the respective receptacle.

reference numeral

10, 10 '

vane

11

airfoil

12

Leitschaufelteller

13

spigot

14

cover surface

15

edge surface

16

chamfer

17

footprint

20

inner ring

21

admission

A

Longitudinal axis of the vane

B ₁

first area of the edge area

B ₂

second area of the edge area

d

Diameter of the journal

D

Diameter of the vane plate

H

average thickness of the guide plate

α

Circulation angle of the first area

β

Orbital angle of the second area

Claims (11)

1. Guide vane (10, 10') for a guide vane ring of a turbomachine, the guide vane having an airfoil (11) and a guide vane disk (12) for mounting said guide vane on an inner ring (20), the guide vane disk having a top surface (14) facing the airfoil, a base surface (17) opposite the top surface, and an edge surface (15) connecting the top surface and the base surface and extending around the circumference thereof, the edge surface having a first region (B1) and a second region (B2), each of which bound a sector of the guide vane disk, the edge surface, in the first region, forming a chamfer (16) of the guide vane disk and, in the second region, extending from the top surface to the base surface along a cylindrical outer surface, characterized in that an inclination provided by the chamfer allows the guide vane to be inserted, in an inclined state, into an associated receptacle (21) in the inner ring, and either in that, in the inclined state, the first region of the guide vane disk projects further into the receptacle than the second region of the guide vane disk, or in that, in the inclined state, the second region of the guide vane disk projects further into the receptacle than the first region of the guide vane disk.
2. Guide vane according to either claim 1 or claim 2, wherein the edge surface has, in the first region, an angle of rotation (α) in a range of from 20° to 170°.
3. Guide vane according to claim 1, wherein the edge surface has, in the second region, an angle of rotation of at least 180°.
4. Guide vane according to any of the preceding claims, wherein a bearing journal (13) extends on the base surface of the guide vane disk in the longitudinal direction of the guide vane.
5. Guide vane ring comprising an inner ring (20) and at least one guide vane (10, 10') according to any of the preceding claims, which guide vane is inserted into an associated receptacle in the inner ring.
6. Guide vane ring according to claim 5, wherein, in the second region, the edge surface of the at least one guide vane rests flush against a wall of the associated receptacle.
7. Method for assembling a guide vane ring which comprises inserting a plurality of guide vanes (10, 10') into respective receptacles (21) in an inner ring (20), the guide vanes having an airfoil (11) and a guide vane disk (12) for mounting said guide vanes on the inner ring (20), the guide vane disk having a top surface (14) facing the airfoil, a base surface (17) opposite the top surface, and an edge surface (15) connecting the top surface and the base surface and extending around the circumference thereof, the edge surface having a first region (B1) and a second region (B2), each of which bound a sector of the guide vane disk, the edge surface, in the first region, forming a chamfer (16) of the guide vane disk and, in the second region, extending from the top surface to the base surface along a cylindrical outer surface, the guide vanes, when inserted, each being brought temporarily into a position that is inclined with respect to the relevant receptacle, in which position a base surface of a guide vane disk to be inserted of the guide vane is oblique with respect to a bottom surface of the receptacle, characterized either in that, in the inclined state, the first region of the guide vane disk projects further into the receptacle than the second region of the guide vane disk, or in that, in the inclined state, the second region projects further into the receptacle than the first region of the guide vane disk.
8. Method according to claim 7, wherein the edge surface has, in the first region, an angle of rotation (α) in a range of from 20° to 170°.
9. Method according to either claim 7 or claim 8, wherein the edge surface has, in the second region, an angle of rotation (β) of at least 180°.
10. Method according to any of claims 7 to 9, wherein a bearing journal (13) extends on the base surface of the guide vane disk in the longitudinal direction of the guide vane.
11. Method according to any of claims 7 to 10, characterized in that the base surface of the guide vane disk is placed flush on a bottom surface of the receptacle by means of a rotational movement of the receptacle and guide vane relative to one another.

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