(19)
(11)EP 3 409 898 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
13.05.2020 Bulletin 2020/20

(21)Application number: 17174287.7

(22)Date of filing:  02.06.2017
(51)Int. Cl.: 
F01D 11/00  (2006.01)
F01D 5/06  (2006.01)

(54)

BELLY BAND SEALS AND METHOD

BAUCHBANDDICHTUNGEN UND VERFAHREN

JOINTS DE BANDE VENTRALE ET PROCÉDÉ


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(43)Date of publication of application:
05.12.2018 Bulletin 2018/49

(73)Proprietor: General Electric Technology GmbH
5400 Baden (CH)

(72)Inventors:
  • SIMONET, Christophe
    5401 Baden (CH)
  • PAWLOWSKI, Marco Christof
    5401 Baden (CH)
  • CATALDI, Giovanni
    5401 Baden (CH)

(74)Representative: BRP Renaud & Partner mbB Rechtsanwälte Patentanwälte Steuerberater 
Königstraße 28
70173 Stuttgart
70173 Stuttgart (DE)


(56)References cited: : 
US-A1- 2004 052 637
US-A1- 2014 255 169
US-A1- 2016 047 263
US-A1- 2009 191 050
US-A1- 2016 010 478
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    TECHNICAL FIELD



    [0001] The present application and resultant patent relate generally to gas turbine engines and more particularly relate to a gas turbine engine having a rotor with a number of belly band seals having a form fitting circumferential anti-rotation feature positioned between adjacent discs.

    BACKGROUND OF THE INVENTION



    [0002] Generally described, gas turbine engines have one or more combustion chambers where a fuel is injected, mixed with a compressed air flow from a compressor, and combusted to generate high pressure combustion gases. In turn, the high pressure combustion gases are expanded in a turbine to produce mechanical work. The compressor and the turbine include stages having a number stationary or non-rotary components, e.g., vane structures, that cooperate with a number of rotatable components, e.g., rotor blades, for compressing and expanding the air flow and the combustion gases therein.

    [0003] The rotor blades are typically mounted on discs that are supported for rotation on a rotor shaft. A disc cooling air cavity may be formed on an inner side of a pair of annular arms between the discs of mutually adjacent stages. Specifically, those arms may be provided with a slot for receiving a sealing strip, also known as a "belly band" seal, which bridges the gap between the discs to prevent the cooling air flowing through the cooling air cavity from leaking into the path of the hot combustion gases.

    [0004] The belly band seal may be segmented and typically may include four (4) band-segments. The segments may be distributed circumferentially and may sit inside a slot created by the two adjacent discs. In order to prevent the belly band seal from sliding freely inside the slot in a circumferential direction, a locking mechanism generally may be required. Known locking mechanisms may include a tab with a tab-nose. The tab generally must be bent during installation. Such bending may introduce a risk of breaking the nose during the installation/bending process and a potential loss of the entire tab in case that the connection cracks and fails. In addition, other tabs features included cuts in the main band which may create high notch stress resultant from loads due to friction, centrifugal forces and thermal expansion. Damage to the seal may lead to a drop in the cooling air flow and possibly a forced outage.

    [0005] US 2014/0255169 A1 discloses a gas turbine including a belly band assembly comprising a sealing band positioned in circumferentially extending slots formed in opposed end faces of adjacent rotor disk arms. The sealing band assembly comprises an anti-rotation device which prevents circumferential movement of the sealing band in the slots. The anti-rotation device comprises a clip member which includes a base portion engaged against the radial inner side of the sealing band and two legs which protrude perpendicularly from the ends of the base portion through notches in the sealing band and into notches formed in the adjacent rotor disk arms. The clip member is fixed on the sealing band by weld joints formed at junctions between the legs and the radial outer side of the sealing band.

    [0006] US 2009/0191050 A1 discloses a turbine rotor including a belly band seal having a sealing strip and an anti-rotation feature in the form of a locking tang which is cut into one axial side of the sealing strip at the mid-span of a sealing strip segment. During assembly, the tang is bent inwardly so as to engage a notch provided in the corresponding disk arm.

    [0007] US 2016/0010478 A1 discloses a sealing band with sealing strip segments and an anti-rotation device. The anti-rotation device comprises a raised portion on the sealing strip segment with a first mating surface and a threaded hole, a locking pin comprising a pin section with a raised portion, a planar section, a second mating surface, and a chamfered hole, and a notch provided in a disk arm for receiving the raised portion of the locking pin. A threaded fastener is inserted through the chamfered hole of the locking pin and threaded into the threaded hole of the raised portion on the sealing strip segment to secure the locking pin thereto.

    [0008] US 2016/0047263 A1 discloses a belly band seal comprising an anti-rotation device which includes a strip-shaped locking section attached to the inner surface of a seal strip segment and a notch or aperture thrilled in one disk arm for receiving the locking section.

    [0009] US 2004/0052637 A1 discloses a seal assembly including a shim spanning the gap between opposed turbine members and positioned in respective slots formed therein. A spring member is provided for urging the shim into contact with the turbine members, in particular with the bottom surfaces of the slots in the turbine members.

    SUMMARY OF THE INVENTION



    [0010] The present application and the resultant patent thus provide a rotor as claimed in claim 1, a use of the rotor as claimed in claim 11 and a method as claimed in claim 12.

    [0011] These and other features and improvements of the present application and the resultant patent will become apparent to one of ordinary skill in the art upon review of the following detailed description when taken in conjunction with the several drawings and the appended claims.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0012] 

    Fig. 1 is a schematic diagram of a gas turbine engine showing a compressor, a combustor, a turbine, and a load.

    Fig. 2A is a perspective view of a pair of rotor discs with a known belly band seal therebetween that may be used with the turbine of the gas turbine engine of Fig. 1.

    Fig. 2B is a partial sectional view of the rotor discs and the belly band seal of Fig. 2A.

    Fig. 2C is a further partial sectional view of the rotor disc and the belly band seal of Fig. 2A.

    Fig. 3 is a perspective view of the belly band seal as may be described herein.

    Fig. 4 is a partial sectional view of the belly band seal of Fig. 3.

    Fig. 5 is a side plan view of an alternative embodiment of a belly band seal as may be described herein.


    DETAILED DESCRIPTION



    [0013] Referring now to the drawings, in which like numerals refer to like elements throughout the several views, Fig. 1 shows a schematic diagram of gas turbine engine 10 as may be used herein. The gas turbine engine 10 may include a compressor 15. The compressor 15 compresses an incoming flow of air 20. The compressor 15 delivers the compressed flow of air 20 to a combustor 25. The combustor 25 mixes the compressed flow of air 20 with a pressurized flow of fuel 30 and ignites the mixture to create a flow of combustion gases 35. Although only a single combustor 25 is shown, the gas turbine engine 10 may include any number of combustors 25 configured in a circumferential array and the like. The flow of combustion gases 35 is in turn delivered to a turbine 40. The flow of combustion gases 35 drives the turbine 40 so as to produce mechanical work. The mechanical work produced in the turbine 40 drives the compressor 15 via a shaft 45 and an external load 50 such as an electrical generator and the like.

    [0014] The gas turbine engine 10 may use natural gas, liquid fuels, various types of syngas, and/or other types of fuels and blends thereof. The gas turbine engine 10 may be any one of a number of different gas turbine engines offered by General Electric Company of Schenectady, New York, including, but not limited to, those such as a 7 or a 9 series heavy duty gas turbine engine and the like. The gas turbine engine 10 may have different configurations and may use other types of components. Other types of gas turbine engines also may be used herein. Multiple gas turbine engines, other types of turbines, and other types of power generation equipment also may be used herein together.

    [0015] Figs. 2A-2C show a pair of adjacent rotor discs, a first rotor disc 55 and a second rotor disc 60, that may be positioned in the turbine 40. A belly band seal 65 may be positioned within a slot 70 formed in each of the rotor discs 55, 60 so as to separate the cooling air flow from the hot gas path. As described above, the segments of the belly band seal 65 generally require a locking mechanism to remain in place. Known locking mechanisms, however, may be prone of failure.

    [0016] Figs. 3 and 4 show an example of a belly band seal 100 as may be described herein. The belly band seal 110 may include a seal band 105 formed in four (4) segments 110, although any number of the segments 110 may be used herein. The belly band seal 100 may have any suitable size, shape, or configuration. The segments 110 of the belly band seal 100 may be distributed circumferentially. The segments 110 of the belly band seal 100 may be positioned with a first slot 120 formed in a first rotor disc 130 and a second slot 140 formed in a second rotor disc 150. The slots 120, 140 and the discs 130, 150 may have any suitable size, shape, or configuration. The rotor discs 130, 150 form part of the overall rotor 155. The belly band seal 100 may separate a cooling air cavity 165 from the hot gas path 175. Other components and other configurations may be used herein.

    [0017] The belly band seal 100 also may include a locking mechanism 160. In this example, the locking mechanism 160 may include a tab 170 with a circular or elliptical shape 180. The tab 170 may have any suitable size, shape, or configuration. The tab 170 may brazed or otherwise attached to the seal band 105. The tab 170 may be positioned completely within the edges of the band seal 1 05 with no overhang and no cuts within the band seal 105. The slots 120, 140 of the discs 130, 150 may have a first counter-grove 190 formed in the first slot 120 and a second counter-grove 200 formed in the second slot 140. The counter-groves 190, 200 may be sized for the tab 170 to create a form fit. This form fit between the tab 170 and the counter-grooves 190, 200 may keep the tab 170 in place and transfer tangential/circumferential forces. Other components and other configurations may be used herein.

    [0018] The use of the tabs 170 thus keeps the seal band 105 in place and prevents free circumferential sliding within the slots 120, 140, especially during rotor barring as well as acceleration or deceleration of the rotor. Moreover, the tab 170 may be additionally secured and contained inside the counter-grooves 190, 200 in case the brazed connection fails so as to mitigate the risk that the tab 170 could fall into the flow path. Additionally, the tab 170 is now loaded by compressive stress rather than tensile stress so as to reduce the risk of crack initiation or propagation
    The belly band seal 100 described herein thus provides a simple geometric design that requires a minimum of manufacturing steps as compared to known competitive designs that tend to be more complex and expensive. Moreover, the belly band seal 100 is more secure in that the brazed connection is now mainly loaded by compressive stress instead of tensile stress, which may significantly reduce the risk of failure.

    [0019] Fig. 5 is a further embodiment of a belly band seal 210 as may be described herein. In this example, a counter spring 220 may be positioned on the band seal 105 on the opposite side of the tab 170. The counter spring 220 may be of conventional design and may have any suitable size, shape, or configuration. The counter spring 220 further assists in maintaining the belly band seal 210 in place. Other components and other configurations may be used herein.

    [0020] It should be apparent that the foregoing relates only to certain embodiments of the present application and the resultant patent. Numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the general scope of the invention as defined by the following claims and the equivalents thereof.


    Claims

    1. A rotor (155) for use in a turbine engine (10), comprising:

    a first rotor disc (130) comprising a first slot (120) and a first counter-groove (190);

    a second rotor (150) disc adjacent to the first rotor disc (130) and comprising a second slot (140) and a second counter-groove (200); and

    a belly band seal (100) positioned between the first rotor disc (130) and the second rotor disc (150);

    the belly band seal (100) comprising a band seal (105),

    wherein the band seal (105) is positioned within the first slot (120) and the second slot (140), and

    wherein a locking tab (170) is positioned within the first counter-groove (190) and the second counter-groove (200), characterized in that the band seal comprises the locking tab (170) which is disposed on a radially outer surface of the band seal (105) and brazed thereon.


     
    2. The rotor (155) of claim 1, wherein the locking tab (170) is positioned within the first counter-groove (190) and the second counter-groove (200) in a form fit.
     
    3. The rotor (155) of any preceding claim, wherein the locking tab (170) comprises a circular or an elliptical shape (180).
     
    4. The rotor (155) of any preceding claim, wherein the locking tab (170) is positioned completely within the edges of the band seal (105) with no overhang and no cuts within the band seal (105).
     
    5. The rotor (155) of any preceding claim, wherein the belly band seal (100) comprises a plurality of segments (110).
     
    6. The rotor (155) of claim 5, wherein the belly band seal (100) comprises four segments (110).
     
    7. The rotor (155) of any preceding claim, wherein the belly band seal (100) comprises a counter spring (220).
     
    8. The rotor (155) of claim 7, wherein the counter spring (220) is positioned on the band seal (105) opposite the locking tab (170).
     
    9. The rotor (155) of any preceding claim, wherein the belly band seal (100) comprises a plurality of locking tabs (170).
     
    10. The rotor (155) of any preceding claim, wherein the rotor comprises a turbine (40) rotor (155).
     
    11. Use of the rotor (155) of any preceding claim in a turbine engine (10), wherein the belly band seal (100) separating an air cavity (165) and a hot gas path (175).
     
    12. A method of positioning a belly band seal (100) between a first rotor disc (130) and a second rotor disc (150) for a turbine engine, characterized in disposing and brazing a locking tab (170) onto a radially outer surface of a band seal (105) of the belly band seal (100);
    positioning the band seal (105) within a first slot (120) on the first rotor disc (130) and a second slot (140) on the second rotor disc (150); and
    positioning the locking tab (170) within a first counter-groove (190) on the first rotor disc (130) and a second counter-groove (200) on the second rotor disc (150).
     


    Ansprüche

    1. Rotor (155) für den Einsatz in einem Turbinentriebwerk (10), umfassend:

    eine erste Rotorscheibe (130), die einen ersten Spalt (120) und eine erste Gegennut (190) umfasst;

    eine zweite Rotorscheibe (150), die der ersten Rotorscheibe (130) benachbart ist und einen zweiten Spalt (140) und eine zweite Gegennut (200) umfasst; und

    eine Bauchbanddichtung (100), die zwischen der ersten Rotorscheibe (130) und der zweiten Rotorscheibe (150) positioniert ist;

    wobei die Bauchbanddichtung (100) eine Banddichtung (105) umfasst,

    wobei die Banddichtung (105) innerhalb des ersten Spalts (120) und des zweiten Spalts (140) positioniert ist, und

    wobei eine Verriegelungslasche (170) innerhalb der ersten Gegennut (190) und der zweiten Gegennut (200) positioniert ist, dadurch gekennzeichnet, dass die Banddichtung die Verriegelungslasche (170) umfasst, die an einer radial äußeren Oberfläche der Banddichtung (105) angeordnet und daran angelötet ist.


     
    2. Rotor (155) nach Anspruch 1, wobei die Verriegelungslasche (170) innerhalb der ersten Gegennut (190) und der zweiten Gegennut (200) formschlüssig positioniert ist.
     
    3. Rotor (155) nach einem der vorstehenden Ansprüche, wobei die Verriegelungslasche (170) eine kreisförmige oder elliptische Form (180) aufweist.
     
    4. Rotor (155) nach einem der vorstehenden Ansprüche, wobei die Verriegelungslasche (170) vollständig innerhalb der Ränder der Banddichtung (105), ohne Überstand und ohne Schnitte innerhalb der Banddichtung (105) positioniert ist.
     
    5. Rotor (155) nach einem der vorstehenden Ansprüche, wobei die Bauchbanddichtung (100) mehrere Segmente (110) umfasst.
     
    6. Rotor (155) nach Anspruch 5, wobei die Bauchbanddichtung (100) vier Segmente (110) umfasst.
     
    7. Rotor (155) nach einem der vorstehenden Ansprüche, wobei die Bauchbanddichtung (100) eine Gegenfeder (220) umfasst.
     
    8. Rotor (155) nach Anspruch 7, wobei die Gegenfeder (220) an der Banddichtung (105) gegenüber der Verriegelungslasche (170) positioniert ist.
     
    9. Rotor (155) nach einem der vorstehenden Ansprüche, wobei die Bauchbanddichtung (100) mehrere Verriegelungslaschen (170) umfasst.
     
    10. Rotor (155) nach einem der vorstehenden Ansprüche, wobei der Rotor einen Rotor (155) einer Turbine (40) umfasst.
     
    11. Verwendung des Rotors (155) nach einem der vorstehenden Ansprüche in einem Turbinentriebwerk (10), wobei die Bauchbanddichtung (100) einen Lufthohlraum (165) und einen Heißgaspfad (175) trennt.
     
    12. Verfahren zum Positionieren einer Bauchbanddichtung (100) zwischen einer ersten Rotorscheibe (130) und einer zweiten Rotorscheibe (150) für ein Turbinentriebwerk, gekennzeichnet durch Anordnen und Hartlöten einer Verriegelungslasche (170) auf einer radial äußeren Oberfläche einer Banddichtung (105) der Bauchbanddichtung (100);
    Positionieren der Banddichtung (105) innerhalb eines ersten Spalts (120) an der ersten Rotorscheibe (130) und eines zweiten Spalts (140) an der zweiten Rotorscheibe (150); und
    Positionieren der Verriegelungslasche (170) innerhalb einer ersten Gegennut (190) an der ersten Rotorscheibe (130) und einer zweiten Gegennut (200) an der zweiten Rotorscheibe (150).
     


    Revendications

    1. Rotor (155) pour une utilisation dans un moteur à turbine (10), comprenant :

    un premier disque de rotor (130) comprenant une première fente (120) et une première contre-rainure (190) ;

    un deuxième disque de rotor (150) adjacent au premier disque de rotor (130) et comprenant une deuxième fente (140) et une deuxième contre-rainure (200) ; et

    un joint de bande ventrale (100) positionné entre le premier disque de rotor (130) et le deuxième disque de rotor (150) ;

    le joint de bande ventrale (100) comprenant un joint de bande (105),

    dans lequel le joint de bande (105) est positionné à l'intérieur de la première fente (120) et de la deuxième fente (140), et

    dans lequel une languette de verrouillage (170) est positionnée à l'intérieur de la première contre-rainure (190) et de la deuxième contre-rainure (200), caractérisé en ce que le joint de bande comprend la languette de verrouillage (170) qui est disposée sur une surface radialement externe du joint de bande (105) et brasée sur celui-ci.


     
    2. Rotor (155) selon la revendication 1, dans lequel la languette de verrouillage (170) est positionnée à l'intérieur de la première contre-rainure (190) et de la deuxième contre-rainure (200) dans un ajustement de forme.
     
    3. Rotor (155) selon une quelconque revendication précédente, dans lequel la languette de verrouillage (170) comprend une forme circulaire ou elliptique (180).
     
    4. Rotor (155) selon une quelconque revendication précédente, dans lequel la languette de verrouillage (170) est positionnée complètement à l'intérieur des bords du joint de bande (105) sans débordement et sans découpe à l'intérieur du joint de bande (105).
     
    5. Rotor (155) selon une quelconque revendication précédente, dans lequel le joint de bande ventrale (100) comprend une pluralité de segments (110).
     
    6. Rotor (155) selon la revendication 5, dans lequel le joint de bande ventrale (100) comprend quatre segments (110).
     
    7. Rotor (155) selon une quelconque revendication précédente, dans lequel le joint de bande ventrale (100) comprend un contre-ressort (220).
     
    8. Rotor (155) selon la revendication 7, dans lequel le contre-ressort (220) est positionné sur le joint de bande (105) à l'opposé de la languette de verrouillage (170).
     
    9. Rotor (155) selon une quelconque revendication précédente, dans lequel le joint de bande ventrale (100) comprend une pluralité de languettes de verrouillage (170).
     
    10. Rotor (155) selon une quelconque revendication précédente, dans lequel le rotor comprend un rotor (155) de turbine (40).
     
    11. Utilisation du rotor (155) selon une quelconque revendication précédente dans un moteur à turbine (10), dans laquelle le joint de bande ventrale (100) sépare une cavité d'air (165) et un trajet de gaz chaud (175).
     
    12. Procédé de positionnement d'un joint de bande ventrale (100) entre un premier disque de rotor (130) et un deuxième disque de rotor (150) pour un moteur à turbine, caractérisé par la disposition et le brasage d'une languette de verrouillage (170) sur une surface radialement externe d'un joint de bande (105) du joint de bande ventrale (100) ;
    le positionnement du joint de bande (105) à l'intérieur d'une première fente (120) sur le premier disque de rotor (130) et d'une deuxième fente (140) sur le deuxième disque de rotor (150) ; et
    le positionnement de la languette de verrouillage (170) à l'intérieur d'une première contre-rainure (190) sur le premier disque de rotor (130) et d'une deuxième contre-rainure (200) sur le deuxième disque de rotor (150).
     




    Drawing












    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description