EP3287604A2 - Positioning element with recesses for a guide vane assembly - Google Patents

Abstract

The invention relates to a positioning element (10) for a vane arrangement of a vane stage of a gas turbine, having at least one circumferentially curved (UR) base portion (12); a plurality of circumferentially (UR) adjacent to each other at the base portion (12) arranged receiving openings (14) whose opening axis extends substantially in the radial direction and which are adapted to receive a respective radially inner vane portion; a coupling portion (18) provided on the base portion (12) and coupleable or coupled to a seal carrier of a seal assembly. According to the invention, it is proposed that at least one recess (16) is provided in the base section (12), which is arranged between two adjacent receiving openings (14) and extends from the inside to the outside at least in the radial direction (RR).

Description

The present invention relates to a positioning member for a stator vane stage of a gas turbine engine having at least one circumferentially curved base portion; a plurality of circumferentially adjacent to each other at the base portion arranged receiving openings whose opening axis extends substantially in the radial direction and which are adapted to receive a respective radially inner vane portion; a provided at the base portion coupling portion which is coupled or coupled with a seal carrier a seal assembly.

Directional information such as "axial" or "axial", "radial" or "radial" and "circumferential" are basically based on the machine axis of the gas turbine to understand, unless the context explicitly or implicitly otherwise results. An addressed vane stage can be arranged in the region of a compressor or in the region of the turbine. The feature coupling portion is to be understood broadly and includes, for example, a portion which allows a positive connection with a counterpart of a seal carrier. However, the coupling portion may also simply be an area or area of the base portion to which a sealing element may be directly attached.

Such a positioning element can also be referred to as a position ring or a position-half ring. In general, the circular arrangement is achieved in a gas turbine by two semicircular position half rings which abut one another in a common parting plane. It has been found that, due to the thermal conditions, a radial temperature gradient is formed in the position halves, wherein the position half rings are radially outwardly subject to a greater elongation in the circumferential direction than radially inward. This stronger radially outer circumferential extent leads in particular also in the region of the parting plane to strong deformations of the positioning element and seal carrier coupled thereto. These deformations can also be described as constrictions and are known by the term cording effect. This has the consequence that in particular the seal carrier or its sealing elements come into contact with these rotating sealing fins, so that a strong wear of the sealing elements occurs. The cording effect leads in the region of the parting plane in particular to a narrowing or local Diameter reduction when the gas turbine is accelerated, and an expansion or local diameter increase when the gas turbine is slowed down.

The object of the invention is to provide a positioning element in which the cording effect is reduced.

For this purpose, it is proposed that at least one recess is provided in the base section, which is arranged between two adjacent receiving openings and extends at least in the radial direction from the inside to the outside. The provision of such recesses allows the positioning element in the region of the recess has a lower effective radial height, on which the temperature gradient acts, and which has an influence on the elongation of the positioning element. If such recesses are provided along the circumference at a plurality of locations between the respective receiving opening, the cording effect can be influenced since the deformations that occur are smaller than in the case of a continuous positioning element without recesses. The recesses in the positioning element also lead to a reduced flexural rigidity of the positioning element. In addition to the thermal effects, the cording effect is also influenced by the ratio of the bending stiffness of the positioning element and the seal carrier. It is advantageous if the positioning element is "softer" or less stiff, because in this way the cording effect is less. Furthermore, in a less rigid positioning a stiffer seal carrier counteract the constriction of the positioning element.

The positioning element may be annular and have two semicircular base sections.

A reduction of the cording effect and thus of constrictions on the positioning element also leads to a reduction of local inlets at a dividing plane from the semicircular base sections. Lower constrictions prevent the formation of gaps and leaks, which has a positive influence on the efficiency and the surge limit, in particular because leaks at the sealing elements can be reduced.

Furthermore, due to the small inlets, less stress can be achieved on the sealing elements, in particular also on rotor sealing fins and their coating. this leads to to an improved or extended durability, so that the repair and maintenance costs can be reduced.

The coupling portion may include at least one of an axial front groove and an axially rear groove extending on the base portion along the circumferential direction. These two circumferential grooves serve in particular to couple a seal carrier with the positioning element.

According to a first embodiment, the axially forward groove and the axially rearward groove may have substantially the same distance in the radial direction from a radial inner side of the base portion. Andres expressed, lie the two grooves at about the same level or have of a machine axis substantially the same distance (radius).

Further, in the first embodiment, the recess may extend in the axial direction between two accommodation openings and extend from an axially front surface of the base portion to an axially rear surface of the base portion. In this case, the recess may be formed as a slot in the base section.

Further, in the first embodiment, the recess along the axial direction may have a changing radial height or have a constant height. Furthermore, the recess along the axial direction may have a varying width in the circumferential direction or have a constant width. By appropriate design or dimensioning of the recesses or the slot of the cording effect can be selectively influenced, especially taking into account that the radial temperature gradient changes over the axial length.

According to a second embodiment, the recess can extend in an axially rear region of the base section in the circumferential direction, such that outer walls of the receiving openings that are substantially cylindrically formed from axially rearward are visible. In this case, the recess can be limited in the axial direction by an axially front wall portion. This results in a continuous in an axially rear portion recess which extends in the axial direction forward between the receiving openings and ends at the axially front wall portion.

In the second embodiment, the axially front groove and the axially rear groove may have a different distance from a radial inner side of the base portion.

The positioning element of the second embodiment can be produced by means of an additive manufacturing method, in particular by means of selective laser melting.

The invention further relates to a seal carrier for a seal assembly having a circumferentially curved base portion on which a sealing element is provided radially inwardly; a negative feedback portion which is coupled or coupled to a coupling portion of a positioning member, wherein the negative feedback portion has an axially front spring portion and an axially rear spring portion, which are inserted or inserted with corresponding grooves of the coupling portion of the positioning element. It is proposed that the axially front spring section and the axially rear spring section have a different distance from a radial inner side of the base section. Such a seal carrier is particularly suitable for coupling to a positioning element of the second embodiment.

The spring sections may be mounted on an axially front support wall and on an axially rear support wall, such that the two spring sections are facing each other in the axial direction.

The base portion may have radially outward inclined with respect to the axial direction and the radial direction cover portion. Such an inclined cover section serves in particular to cover the recess in a coupled state on the positioning element.

In the base section, in particular in its cover section, a plurality of openings can be provided next to each other in the circumferential direction.

Finally, the invention also relates to a guide vane carrier arrangement for a gas turbine, in particular aircraft gas turbine, with at least one positioning element according to the first embodiment and at least one associated seal carrier or with at least one positioning element according to the second embodiment and at least one seal carrier described above.

• Fig. 1 zeigt in einer schematischen Darstellung eine Draufsicht auf eine axiale Vorderseite eines Positionierungselements gemäß einer ersten Ausführungsform.
• Fig. 2 zeigt in einer schematischen Perspektivansicht von axial vorne einen Teil des Positionierungselements gemäß der ersten Ausführungsform.
• Fig. 3 zeigt in einer schematischen Perspektivdarstellung von radial innen etwa das halbe das Positionierungselement der Fig. 1
• Fig. 4 zeigt in einer schematischen Perspektivansicht von radial innen einen vergrößerten Teil des Positionierungselements der Fig. 3.
• Fig. 5 zeigt eine vergrößerte Perspektivdarstellung des Positionierungselements von axial hinten.
• Fig. 6 zeigt in den Teilfiguren A) und B) jeweilige Schnittdarstellungen des Positionierungselement, die in etwa der Schnittlinie VI-VI der Fig. 3 entsprechen, wobei die Fig. 6A) eine Variante darstellt mit variabler radialer Höhe der Aussparung, und Fig. 6B) eine Variante darstellt mit gleichbleibender radialer Höhe der Aussparung, was dem Beispiel der Fig. 1-4 entspricht.
• Fig. 7 zeigt in den Teilfiguren A) und B) Varianten des Positionierungselements der ersten Ausführungsform in einer zur Fig. 1 ähnlichen Darstellung.
• Fig. 8 zeigt in einer schematischen Perspektivansicht von axial schräg hinten einen Teil eines Positionierungselements einer zweiten Ausführungsform.
• Fig. 9 zeigt in einer schematischen Perspektivansicht von axial schräg vorne einen Teil eines Dichtungsträgers, der mit dem Positionierungselement der Fig. 8 koppelbar ist.

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

• Fig. 1 shows a schematic representation of a plan view of an axial front side of a positioning element according to a first embodiment.
• Fig. 2 shows in a schematic perspective view of an axially front part of the positioning member according to the first embodiment.
• Fig. 3 shows in a schematic perspective view of radially inward about half of the positioning of the Fig. 1
• Fig. 4 shows in a schematic perspective view from radially inside an enlarged part of the positioning of the Fig. 3 ,
• Fig. 5 shows an enlarged perspective view of the positioning element from the rear axially.
• Fig. 6 shows in the sub-figures A) and B) respective sectional views of the positioning element, which is approximately the section line VI-VI of Fig. 3 correspond, wherein the Fig. 6A ) represents a variant with variable radial height of the recess, and Fig. 6B ) represents a variant with the same radial height of the recess, which is the example of Fig. 1-4 equivalent.
• Fig. 7 shows in the partial figures A) and B) variants of the positioning element of the first embodiment in a to Fig. 1 similar representation.
• Fig. 8 shows in a schematic perspective view of axially obliquely behind a part of a positioning element of a second embodiment.
• Fig. 9 shows in a schematic perspective view of axially obliquely in front of a part of a seal carrier, with the positioning of the Fig. 8 can be coupled.

Fig. 1 shows in a simplified schematic plan view in the axial direction, a first embodiment of a positioning element 10 and Fig. 2 shows an enlarged section of the positioning element 10. As can be seen from these figures, the positioning element 10 has a base portion 12 which is bent in a semicircular manner. In the base portion 12 a plurality of circumferentially UR side by side arranged receiving openings 14 are provided. The receiving openings 14 are used in particular for receiving guide vanes, not shown here. In the circumferential direction UR 14 respective recesses 16 are visible between two adjacent receiving openings. These recesses 16 extend in the radial direction RR from the inside to the outside. In the area of the dashed line TE ( Fig. 1 ) is the so-called parting line indicated. In the region of this parting plane, two semicircular base sections 12 adjoin one another, so that a complete circular positioning element 10 can be formed. The base portion 12 further includes a radially inner coupling portion 18. At this coupling portion 18, a seal carrier, not shown here, can be attached. The recesses 16 in this first embodiment extend in particular through the coupling section 18. As already mentioned in the introduction, the characteristic coupling section can be broadly understood and comprises, for example, a section which allows a positive connection with a counterpart of a seal carrier. However, the coupling portion may also simply be an area or area of the base portion to which a sealing element may be directly attached.

3 and 4 show the positioning element 10, which is referred to in the jargon as a locating ring or positioning ring, in a perspective view of radially inward. In the Fig. 3 In this case, in particular, an abutment surface 20 of the base section 12 can be seen. With this abutment surface 20, the base section 12 lies in the region of the parting plane TE (FIG. Fig. 1 ) on the other semi-circular base portion. It can also be seen from this illustration that the coupling section 18 has a type of inverted T-profile. As a result, an axially front groove 22 and an axially rearward groove 24 is formed. With these two grooves 22, 24 corresponding counterparts or spring-like negative feedback portions of a seal carrier are to be connected. The recesses 16 extend in particular through the grooves 22, 24th

While in the Fig. 1 to 4 between each two adjacent receiving openings 14, a recess 18 is arranged, shows the Fig. 5 schematically and simplified a variant in which a recess 16 is provided only every two receiving openings 14. Fig. 5 is a view from the rear axially of the base portion 12. From this illustration and also from the previous illustrations it can be seen that the recesses 16 of extend radially inward radially outward. However, the recesses 16 do not sever the base portion 12. Rather, the recesses 16 are formed slit-like. The width in the circumferential direction of such a recess 16 along the axial direction and / or along the radial direction may be constant or variable.

The Fig. 6A) and 6B ) are sectional views in the region of a recess 16 or slot, as indicated by the section line VI-VI of Fig. 3 is indicated. A radial height RH of the recesses 16 may, as shown in the sectional views of Fig. 6A) and 6B ), also be consistent or variable. In the Fig. 6A) a variable height RH of the recess 16 and the slot is shown. In Fig. 6B ) is shown over the axial extent constant height RH.

From the variants of Fig. 6A) and 6B ) and the above description regarding the possible adjustment of the width of the recesses, it is clear that the recesses can be adapted to respective properties, in particular the radial temperature gradient, by changing their dimensions in height and width. Such temperature gradients also depend, in particular, on further constructional boundary conditions of an inner ring and vane arrangement of a gas turbine.

In Figure 7 In the subfigures A) and B) two variants of a base section 12 are shown. The base portion 12 in FIG Fig. 7A ) has, starting from the dividing plane TE in each case some, here in each case five recesses 16. The recesses are thus not distributed along the circumference of the entire base portion 12, but only near the dividing plane TE.

At the base section 12 of Fig. 7B ) recesses 16 are provided along the entire circumference, however, only a recess 16 is provided for all two receiving openings 14. The Fig. 7B ) corresponds in this regard with the Fig. 5 ,

From the Fig. 7 It can be seen that the recesses 16 can be provided at different distances from each other and partially or completely along the circumference of the base portion 12. This also shows that the number and arrangement of the recesses 16 according to the frame conditions, such as radial temperature gradient and / or stiffness of the positioning element or seal carrier, can be selected, so that the cording effect can be kept as low as possible depending on the design of the gas turbine ,

Fig. 8 shows a second embodiment of a positioning member 110 with a base portion 112 in a perspective view obliquely from behind (axial direction). Between receiving openings 114, respective recesses 116 are provided which extend at least in the radial direction RR. In contrast to the recesses 16 of the first embodiment ( Fig. 1-7 ) the recesses 116 are not formed as slots, but are designed so that the outer peripheral walls 115 of the receiving openings 114 are visible.

The base portion also has a coupling portion 118 having an axially forward groove 122 and an axially rearward groove 124. In contrast to the first embodiment, the axially rearward groove 124 is disposed radially outward of the base portion 112. This changed arrangement of the axially rearward groove 124 is due to the larger recesses 116 and radially missing material on which an axially rearward groove could be formed as in the first embodiment. The axially rearward groove 124 is located radially farther outward than the axially frontward groove 122, relative to a machine axis of the gas turbine. The recesses 116 are bounded axially in front by an axially front wall section 117. In this case, the axially front wall section 117 also forms the rear side or opposite side of a groove bottom of the axially front groove 122.

The design presented here of the base portion 112 with the recesses 116 and the coupling portion 118 with the two grooves 122, 124 is optimized so that the base portion 112 by means of an additive manufacturing process, in particular by means of selective laser melting, can be produced. In this case, the semicircular base portion 112 can be constructed, for example, from the axial front to the rear axially in layers.

Due to the changed construction of the base section 112, in Fig. 9 a part of a seal carrier 130 adapted to this construction is presented. The seal carrier 130 includes negative feedback portions 132, 134. The negative feedback portions 132, 134 project in the axial direction such that spring-like projections are formed. Accordingly, the negative feedback portion 132 may engage with the axially front groove 122 of the base portion, and the negative feedback portion 134 may engage with the axially rearward groove 124 of the base portion 112. A sealing element not shown here would be provided on the radial inner side 136 of the seal carrier 130. The negative feedback sections 132, 134 are formed as an axially front spring portion 132 and as an axially rear spring portion 134. In particular, they have a different distance to a radial inner side of a base section 138.

The seal carrier 130 has in the assembled state the receiving openings 114 opposite (radially inwardly) arranged base portion 138. This base section merges into or comprises a sloping cover section 140. The cover section 140 is used, in particular, to enable manufacturability by means of selective laser melting. In the inclined cover portion 140 a plurality of openings 142 are provided. These openings 142 also serve to produce by means of selective laser melting. Thus, the seal carrier 130 is designed in terms of its shape so that it can be produced by means of an additive manufacturing process, in particular by means of selective laser melting.

Both embodiments have in common that in the base portion 12, 112 recesses 16, 116 are provided, which serve to reduce the cording effect on the positioning element 10, 110. The recesses act in particular to provide interruptions, so that a radial temperature gradient can not unfold its full effect along the entire circumference of the positioning element 10, 110. Furthermore, the recesses serve to reduce the flexural rigidity of the positioning element, which also reduces the cording effect.

LIST OF REFERENCE NUMBERS

10, 110

positioner

12, 112

base section

14, 114

receiving opening

115

outer peripheral wall

16, 116

recess

117

axially front wall section

18, 118

coupling portion

20

abutting face

22, 122

axial front groove

24, 124

axial rear groove

130

seal carrier

132

Feedback section

134

Feedback section

136

radial inside

138

base portion

140

cover

142

openings

Claims (15)

Positioning element (10) for a vane arrangement of a vane stage of a gas turbine, with
at least one circumferentially (UR) curved base portion (12; 112);
a plurality of circumferentially (UR) adjacent to each other at the base portion (12; 112) arranged receiving openings (14; 114) whose opening axis extends substantially in the radial direction and which are adapted to receive a respective radially inner vane portion;
a coupling portion (18; 118) provided on the base portion (12; 112) and coupleable or coupled to a seal support (130) of a seal assembly;
characterized in that
at least one recess (16; 116) is provided in the base section (12; 112) which is arranged between two adjacent receiving openings (14; 114) and extends from the inside to the outside at least in the radial direction (RR). Positioning element according to claim 1, characterized in that it is annular and has two semicircular base portions (12, 112). A positioning element according to claim 1 or 2, characterized in that the coupling portion (18; 118) comprises at least one axially forward groove (22; 122) and an axially rearward groove (24; 124) extending along the base portion (12; Circumferential direction (UR) run. Positioning element according to claim 3, characterized in that the axially front groove (22) and the axially rearward groove (24) in the radial direction (RR) have substantially the same distance to a radial inner side of the base portion (12). Positioning element according to one of claims 1 to 4, characterized in that the recess (16) extends in the axial direction (AR) between two receiving openings (14) and from an axially front surface of the base portion (12) to an axially rear surface of the base portion (12). 12). Positioning element according to claim 5, characterized in that the recess (16) is formed as a slot in the base portion (14). Positioning element according to claim 6, characterized in that the recess (16) along the axial direction (AR) has a changing radial height (RH) or a constant height (RH). Positioning element according to claim 6 or 7, characterized in that the recess (16) along the axial direction (AR) has a varying width in the circumferential direction (UR) or has a constant width. Positioning element according to one of claims 1 to 3, characterized in that the recess (116) in an axially rear portion of the base portion (112) in the circumferential direction (UR), such that from the rear axially substantially cylindrically shaped outer walls (115) of the receiving openings (114) are visible. Positioning element according to one of claims 1 to 3 or according to claim 9, characterized in that the recess (116) in the axial direction (AR) by an axially front wall portion (117) is limited. Positioning element according to claim 9 or 10 or any one of claims 1 to 3, characterized in that the axially front groove (122) and the axially rearward groove (124) at a different distance to a radially inner side of the base portion (112). Positioning element according to one of claims 9 to 11, characterized in that it is produced by means of an additive manufacturing process, in particular by means of selective laser melting. Seal carrier (13) for a seal arrangement with
a circumferentially curved (UR) base portion (138) on which a sealing member is provided radially inward;
a negative feedback portion (132, 134) to be coupled or coupled to a coupling portion (122, 124) of a positioning member (110),
the negative feedback portion comprising an axially forward spring portion (132) and an axially rearward spring portion (134) insertable or inserted with corresponding grooves (122, 124) of the coupling portion of the positioning member (110),
characterized in that
the axially front spring portion (132) and the axially rearward spring portion (134) have a different distance from a radial inner side of the base portion (130). Seal carrier according to claim 13, characterized in that the spring portions (132, 134) are mounted on an axially front support wall and on an axially rear support wall, such that the two spring portions (132, 132) in the axial direction (AR) facing each other, wherein preferably the base portion (138) radially outwardly with respect to the axial direction (AR) and the radial direction (RR) inclined cover portion (140), preferably in the base portion (138), in particular in its cover portion (140) in the circumferential direction (UR) a plurality of openings (142) are provided side by side. Guide vane carrier assembly for a gas turbine, in particular aircraft gas turbine, with
at least one positioning element (10) according to one of claims 1 to 3 and at least one associated seal carrier or
with at least one positioning element (110) according to one of Claims 9 to 12 and at least one seal carrier (130) according to one of Claims 13 to 14.

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