(19)
(11)EP 3 252 275 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
15.09.2021 Bulletin 2021/37

(21)Application number: 17174058.2

(22)Date of filing:  01.06.2017
(51)International Patent Classification (IPC): 
F01D 11/00(2006.01)
F16J 15/3268(2016.01)
F16J 15/08(2006.01)
F01D 25/28(2006.01)
(52)Cooperative Patent Classification (CPC):
F01D 11/005; F01D 25/285; F16J 15/3268; F16J 15/0887; F05D 2250/75

(54)

JOINED TWO PLY W SEAL

VERBUNDENE ZWEILAGIGE W-DICHTUNG

JOINT W À DEUX ÉPAISSEURS ASSEMBLÉ


(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

(30)Priority: 02.06.2016 US 201615171942

(43)Date of publication of application:
06.12.2017 Bulletin 2017/49

(73)Proprietor: Raytheon Technologies Corporation
Farmington, CT 06032 (US)

(72)Inventor:
  • DAVIS, Timothy M.
    Kennebunk, ME Maine 04043 (US)

(74)Representative: Dehns 
St. Bride's House 10 Salisbury Square
London EC4Y 8JD
London EC4Y 8JD (GB)


(56)References cited: : 
WO-A1-00/12920
US-A- 5 249 814
US-A- 4 759 555
US-A1- 2004 239 053
  
      
    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

    FIELD



    [0001] The present disclosure is directed to a gasket seal and, more particularly, to a seal for use in a turbine section of a gas turbine engine.

    BACKGROUND



    [0002] Gas turbine engines, such as those that power modern commercial and military aircraft, may include a fan section to propel the aircraft, a compressor section to pressurize a supply of air from the fan section, a combustor section to burn fuel in the presence of the pressurized air, and a turbine section to extract energy from the resultant combustion gases and to generate thrust.

    [0003] The compressor section and turbine section each have multiple stages of rotors that rotate about a central axis and multiple stages of stators that are stationary relative to the central axis. It is desirable to reduce fluid leakage between the stages of rotors and stators. Bellows seals, also referred to as "w-seals," are frequently used to reduce fluid leakage between the stages of rotors and stators.

    [0004] Bellows seals may include a first ply and a second ply adjacent to the first ply. It may be desirable to reduce the likelihood of the first ply separating from the second ply during use of the bellows seals. Stated differently, it may be desirable to reduce the likelihood of the first ply moving relative to the second ply at a location away from an area of intentional slip (also referred to as a slip joint). Furthermore, the bellows seals may be manufactured at a facility remote from where the gas turbine engine will be assembled.

    [0005] WO 00/12920 discloses a prior art metal gasket bellows seal in accordance with the preamble of claims 1.

    [0006] US 4,759,555 discloses a prior art split ring seal with slip joint.

    SUMMARY



    [0007] The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated otherwise. These features and elements as well as the operation thereof will become more apparent in light of the following description and the accompanying drawings. It should be understood, however, the following description and drawings are intended to be exemplary in nature and non-limiting.

    [0008] In an aspect of the present invention, there is provided a metal gasket bellows seal according to claim 1.

    [0009] In the foregoing metal gasket bellows seal, the second ply may be coupled to the first ply at multiple locations.

    [0010] In any of the foregoing metal gasket bellows seals, the spot joining may include at least one of at least one of resistance welding, laser welding or electron beam welding.

    [0011] Any of the foregoing metal gasket bellows seals may also include adhesive coupled to the first ply and the second ply at the slip joint.

    [0012] In any of the foregoing metal gasket bellows seals, the first location may be positioned on a first leg of the metal gasket bellows seal.

    [0013] In any of the foregoing metal gasket bellows seals, the first location may be positioned between an inner diameter edge of the metal gasket bellows seal and an outer diameter edge of the metal gasket bellows seal.

    [0014] In any of the foregoing metal gasket bellows seals, the first location may be positioned a first distance from the outer diameter edge of the metal gasket bellows seal that is between 40 percent and 60 percent of a second distance from the outer diameter edge of the metal gasket bellows seal to the inner diameter edge of the metal gasket bellows seal.

    [0015] In an embodiment of the present invention, there is provided a metal gasket bellows seal according to claim 6.

    [0016] In any of the foregoing metal gasket bellows seals, the adhesive may be located at an outer diameter edge of the metal gasket bellows seal or at an inner diameter edge of the metal gasket bellows seal.

    [0017] In any of the foregoing metal gasket bellows seals, the adhesive may be configured to melt at a melting temperature that is less than an operating temperature of an environment of the metal gasket bellows seal.

    [0018] In any of the foregoing metal gasket bellows seals, the operating temperature of the environment of the metal gasket bellows seal may be between 427°C and 649°C (800 degrees Fahrenheit and 1500 degrees Fahrenheit) and the melting temperature may be between 204°C and 316°C (400 degrees Fahrenheit and 600 degrees Fahrenheit).

    [0019] In any of the foregoing metal gasket bellows seals, the adhesive may resist an increase or decrease in a diameter of the metal gasket bellows seal during at least one of transportation or handling of the metal gasket bellows seal.

    [0020] In any of the foregoing metal gasket bellows seals, the adhesive may be applied to the metal gasket bellows seal at a single location.

    [0021] In any of the foregoing metal gasket bellows seals, the second ply may be coupled to the first ply at a first location away from the slip joint via at least one of resistance welding, laser welding or electron beam welding.

    [0022] In an aspect of the present invention, there is provided a method as set forth in claim 12.

    [0023] In any of the foregoing methods, the adhesive may be configured to melt at a melting temperature that is less than an operating temperature of an environment of the metal gasket bellows seal.

    [0024] Any of the foregoing methods may also include performing a green run of the gas turbine engine to melt the adhesive.

    [0025] In any of the foregoing methods, the adhesive may resist an increase or a decrease of a diameter of the metal gasket bellows seal during the transporting the metal gasket bellows seal to the location for assembly of the gas turbine engine.

    [0026] In any of the foregoing methods, the adhesive may be located at an outer diameter edge of the metal gasket bellows seal or at an inner diameter edge of the metal gasket bellows seal.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0027] Various features will become apparent to those skilled in the art from the following detailed description of the disclosed, non-limiting, embodiments. The drawings that accompany the detailed description can be briefly described as follows:

    FIG. 1 is a schematic cross-section of a gas turbine engine, in accordance with various embodiments;

    FIG. 2 is an enlarged schematic cross-section of a high pressure turbine section of the gas turbine engine of FIG. 1, in accordance with various embodiments;

    FIG. 3 is an enlarged view of the turbine section shown in FIG. 2 illustrating a blade outer air seal, a vane, and a metal gasket bellows seal, in accordance with various embodiments;

    FIG. 4 is a drawing of the metal gasket bellows seal illustrated in FIG. 3, in accordance with various embodiments;

    FIG. 5A is an axial view of a portion of the metal gasket bellows seal of FIG. 4, in accordance with various embodiments;

    FIG. 5B is an axial view showing the entire circumference of the metal gasket bellows seal of FIG. 4, in accordance with various embodiments;

    FIG. 6 is a drawing of a metal gasket bellows seal, in accordance with various embodiments;

    FIG. 7A is an axial view of a portion of the metal gasket bellows seal of FIG. 6, in accordance with various embodiments;

    FIG. 7B is an axial view showing the entire circumference of the metal gasket bellows seal of FIG. 6, in accordance with various embodiments; and

    FIG. 8 is a flowchart illustrating a method for assembly of a gas turbine engine that includes a metal gasket bellows seal, in accordance with various embodiments.


    DETAILED DESCRIPTION



    [0028] The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice embodiments of the disclosure, it should be understood that other embodiments may be realized and that logical changes and adaptations in design and construction may be made in accordance with this disclosure and the teachings herein. Thus, the detailed description herein is presented for purposes of illustration only and not limitation. The scope of the disclosure is defined by the appended claims. For example, the steps recited in any of the method or process descriptions may be executed in any order and are not necessarily limited to the order presented. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Also, any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option. Additionally, any reference to without contact (or similar phrases) may also include reduced contact or minimal contact.

    [0029] Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Surface shading lines may be used throughout the figures to denote different parts but not necessarily to denote the same or different materials.

    [0030] As used herein, "aft" refers to the direction associated with the exhaust (e.g., the back end) of a gas turbine engine. As used herein, "forward" refers to the direction associated with the intake (e.g., the front end) of a gas turbine engine.

    [0031] A first component that is "axially outward" of a second component means that a first component is positioned at a greater distance in the aft or forward direction away from the longitudinal center of the gas turbine along the longitudinal axis of the gas turbine, than the second component. A first component that is "axially inward" of a second component means that the first component is positioned closer to the longitudinal center of the gas turbine along the longitudinal axis of the gas turbine, than the second component.

    [0032] A first component that is "radially outward" of a second component means that the first component is positioned at a greater distance away from the engine central longitudinal axis than the second component. A first component that is "radially inward" of a second component means that the first component is positioned closer to the engine central longitudinal axis than the second component. In the case of components that rotate circumferentially about the engine central longitudinal axis, a first component that is radially inward of a second component rotates through a circumferentially shorter path than the second component. The terminology "radially outward" and "radially inward" may also be used relative to references other than the engine central longitudinal axis. For example, a first component of a combustor that is radially inward or radially outward of a second component of a combustor is positioned relative to the central longitudinal axis of the combustor. An A-R-C axis is shown throughout the drawings to illustrate the axial, radial and circumferential directions.

    [0033] In various embodiments and with reference to FIG. 1, an exemplary gas turbine engine 2 is provided. Gas turbine engine 2 may be a two-spool turbofan that generally incorporates a fan section 4, a compressor section 6, a combustor section 8 and a turbine section 10. Alternative engines may include, for example, an augmentor section among other systems or features. In operation, fan section 4 can drive air along a bypass flow-path b while compressor section 6 can drive air along a core flow-path c for compression and communication into combustor section 8 then expansion through turbine section 10. Although depicted as a turbofan gas turbine engine 2 herein, it should be understood that the concepts described herein are not limited to use with turbofans as the teachings may be applied to other types of turbine engines including three-spool architectures.

    [0034] Gas turbine engine 2 may generally comprise a low speed spool 12 and a high speed spool 14 mounted for rotation about an engine central longitudinal axis X-X' relative to an engine static structure 16 via several bearing systems 18-1, 18-2, and 18-3. It should be understood that various bearing systems at various locations may alternatively or additionally be provided, including for example, bearing system 18-1, bearing system 18-2, and bearing system 18-3.

    [0035] Low speed spool 12 may generally comprise an inner shaft 20 that interconnects a fan 22, a low pressure compressor section 24 (e.g., a first compressor section) and a low pressure turbine section 26 (e.g., a first turbine section). Inner shaft 20 may be connected to fan 22 through a geared architecture 28 that can drive the fan 22 at a lower speed than low speed spool 12. Geared architecture 28 may comprise a gear assembly 42 enclosed within a gear housing 44. Gear assembly 42 couples the inner shaft 20 to a rotating fan structure. High speed spool 14 may comprise an outer shaft 30 that interconnects a high pressure compressor section 32 (e.g., second compressor section) and high pressure turbine section 34 (e.g., second turbine section). A combustor 36 may be located between high pressure compressor section 32 and high pressure turbine section 34. A mid-turbine frame 38 of engine static structure 16 may be located generally between high pressure turbine section 34 and low pressure turbine section 26. Mid-turbine frame 38 may support one or more bearing systems 18 (such as 18-3) in turbine section 10. Inner shaft 20 and outer shaft 30 may be concentric and rotate via bearing systems 18 about the engine central longitudinal axis X-X', which is collinear with their longitudinal axes. As used herein, a "high pressure" compressor or turbine experiences a higher pressure than a corresponding "low pressure" compressor or turbine.

    [0036] The core airflow C may be compressed by low pressure compressor section 24 then high pressure compressor section 32, mixed and burned with fuel in combustor 36, then expanded over high pressure turbine section 34 and low pressure turbine section 26. Mid-turbine frame 38 includes airfoils 40, which are in the core airflow path. Turbine sections 26, 34 rotationally drive the respective low speed spool 12 and high speed spool 14 in response to the expansion.

    [0037] Gas turbine engine 2 may be, for example, a high-bypass geared aircraft engine. In various embodiments, the bypass ratio of gas turbine engine 2 may be greater than about six. In various embodiments, the bypass ratio of gas turbine engine 2 may be greater than ten. In various embodiments, geared architecture 28 may be an epicyclic gear train, such as a star gear system (sun gear in meshing engagement with a plurality of star gears supported by a carrier and in meshing engagement with a ring gear) or other gear system. Geared architecture 28 may have a gear reduction ratio of greater than about 2.3 and low pressure turbine section 26 may have a pressure ratio that is greater than about five. In various embodiments, the bypass ratio of gas turbine engine 2 is greater than about ten. In various embodiments, the diameter of fan 22 may be significantly greater than that of the low pressure compressor section 24, and the low pressure turbine section 26 may have a pressure ratio that is greater than about five. The pressure ratio of low pressure turbine section 26 may be measured prior to inlet of low pressure turbine section 26 as related to the pressure at the outlet of low pressure turbine section 26 prior to an exhaust nozzle. It should be understood, however, that the above parameters are exemplary of various embodiments of a suitable geared architecture engine and that the present disclosure contemplates other turbine engines including direct drive turbofans.

    [0038] In various embodiments, the next generation of turbofan engines may be designed for higher efficiency, which may be associated with higher pressure ratios and higher temperatures in the high speed spool 14. These higher operating temperatures and pressure ratios may create operating environments that may cause thermal and mechanical loads that are higher than thermal and mechanical loads conventionally encountered, which may shorten the operational life of current components. In various embodiments, operating conditions in high pressure compressor section 32 may be approximately 1400 degrees Fahrenheit (1400 °F, approximately 760 °C) or more, and operating conditions in combustor 36 may also be significantly higher.

    [0039] In various embodiments, combustor section 8 may comprise one or more combustor 36. As mentioned, the core airflow c may be compressed, then mixed with fuel and ignited in the combustor 36 to produce high speed exhaust gases.

    [0040] With reference now to FIGS. 1 and 2, a portion of high pressure turbine section 34 includes a first rotor blade 200, a vane 202, and a second rotor blade 204. First rotor blade 200 and second rotor blade 204 are each configured to rotate about axis X-X' relative to vane 202 in response to receiving a flow of fluid from combustor section 8. This flow of fluid may be referred to as a gas path and is designated by an arrow 210.

    [0041] Torque is generated by rotation of first rotor blade 200 and second rotor blade 204 in response to first rotor blade 200 and second rotor blade 204 receiving the flow of fluid. Vane 202 is coupled to a frame 214 of high pressure turbine section 34 and conditions the flow of fluid between first rotor blade 200 and second rotor blade 204. Vane 202 is thus a stator and does not rotate relative to axis X-X'. Each of first rotor blade 200, vane 202, and second rotor blade 204 may be considered a stage of high pressure turbine section 34.

    [0042] High pressure turbine section 34 also includes a blade outer air seal (BOAS) 208. BOAS 208 is positioned radially outward from first rotor blade 200 and reduces an amount of fluid that may flow at a location radially outward from first rotor blade 200, thus reducing fluid leakage and, in turn, increasing performance of gas turbine engine 2. Vane 202 also includes an outer diameter platform 206. Outer diameter platform 206 may be coupled to frame 214 and may be integral with, or coupled to, vane 202. In that regard, when vane 202 is referenced herein, it may also refer to outer diameter platform 206. Outer diameter platform 206 may resist movement of vane 202 relative to frame 214.

    [0043] Pressurized air, designated by an arrow 212, is commonly diverted from combustor section 8 and/or compressor section 24 and is used to cool components within high pressure turbine section 34. Fluid in the gas path may have a greater temperature than the pressurized air designated by arrow 212. Thus, the pressurized air designated by arrow 212 may be referred to as a cooling flow.

    [0044] It may be desirable to reduce an amount of fluid that leaks from the gas path between each stage of high pressure turbine section 34 as fluid leakage may reduce performance. Furthermore, it may be undesirable for the hot fluid from the gas path to contact frame 214 or mix with cooling flow 212. Thus, well-sealed gaps between axially-adjacent components, such as between BOAS 208 and vane 202, increase performance aspects of gas turbine engine 2, such as efficiency, and may increase the lifespan of gas turbine engine 2.

    [0045] Referring to FIGS. 2 and 3, high pressure turbine section 34 may include a metal gasket bellows seal, or "W seal," 300 extending axially between BOAS 208 and vane 202. Metal gasket bellows seal 300 may extend circumferentially about high pressure turbine section 34 and may thus be an annular structure. Metal gasket bellows seal 300 has a first side 302 and a second side 304. First side 302 faces radially outward relative to vane 202 and second side 304 faces radially inward relative to vane 202. First side 302 may be exposed to the cooling flow, designated by arrow 212, and second side 304 may be exposed to the gas path flow, designated by arrow 210. Thus, second side 304 may be exposed to greater temperatures and pressures than first side 302.

    [0046] Turning now to FIG. 4, metal gasket bellows seal 300 has an inner diameter edge 420 and an outer diameter edge 418. Metal gasket bellows seal 300 also includes a first ply 400 and a second ply 402. First ply 400 defines at least a portion of outer diameter edge 418 and second ply 402 defines at least a portion of inner diameter edge 420. In various embodiments, first ply 400 may include the same material as second ply 402 and, in various embodiments, first ply 400 may include a different material than second ply 402.

    [0047] Metal gasket bellows seal 300 also includes four legs including a first leg 404, a second leg 406, a third leg 408, and a fourth leg 410. First leg 404 and second leg 406 are separated by a first bend 412, second leg 406 and third leg 408 are separated by a second bend 414, and third leg 408 and fourth leg 410 are separated by a third bend 416. In various embodiments, a metal gasket bellows seal may include any number of legs and bends.

    [0048] First leg 404 is positioned on a first axial end 422 of metal gasket bellows seal 300 and fourth leg 410 is positioned on a second axial end 424 of metal gasket bellows seal 300. In various embodiments, second axial and 424 may be aft of first axial end 422, and in various embodiments, first axial end 422 may be aft of second axial and 424.

    [0049] Referring now to FIGS. 3 and 4, metal gasket bellows seal 300 may occasionally be subjected to stress from vane 202 and BOAS 208, as well as pressures and temperatures present in high pressure turbine section 34. It is undesirable for first ply 400 to move relative to second ply 402 while positioned in high pressure turbine section 34. Metal gasket bellows seal 300 includes a weld 426 at a first location 428 to resist movement of first ply 400 relative to second ply 402. As discussed below, metal gasket bellows seal 300 includes a slip joint designed to accommodate movement of one end of first ply 400 relative to the opposite end of second ply 402. Thus, movement of first ply 400 relative to second ply 402 may not be undesirable at the slip joint and gaps 511 and 509. Movement of first ply 400 relative to second ply 402 at locations other than those previously described may be undesirable as it may reduce the integrity of the metal gasket bellows seal 300.

    [0050] Weld 426 is formed using spot joining, referring to the fact that the weld 426 is applied at a spot on the material. For example, weld 426 may be formed via a resistance weld, a laser weld, an electron beam weld, a gas tungsten arc weld, a metal inert gas weld, or brazing. In that regard, spot joining may include any variety of tack welding along with brazing or any other form of spot joining. In various embodiments, spot joining may not include temporary joining techniques such as glue that will evaporate in normal operating conditions. In order to form a resistance weld between first ply 400 and second ply 402, current is applied through first ply 400 and second ply 402 at first location 428, generating heat and fusing first ply 400 to second ply 402 at first location 428. In order to form a laser weld between first ply 400 and second ply 402, a laser beam is directed at first ply 400 and/or second ply 402 at first location 428, generating heat and fusing first ply 400 to second ply 402 at first location 428. In order to form an electron beam weld between first ply 400 and second ply 402, a beam of electrons is directed at first ply 400 and/or second ply 402 at first location 428, generating heat and fusing first ply 400 to second ply 402 at first location 428.

    [0051] First location 428 may be on first leg 404 of metal gasket bellows seal 300. In various embodiments, weld 426 may be at any location on metal gasket bellows seal 300. It may be preferable for weld 426 to be positioned on a leg of metal gasket bellows seal 300 instead of on a bend, outer diameter edge 418, or inner diameter edge 420. This is because less stress may be applied to a leg than to another location.

    [0052] In various embodiments, metal gasket bellows seal 300 may include a second weld 430 at a second location 432. Second weld 430 may also be formed via resistance welding, laser welding, or electron beam welding. In various embodiments, a second weld may be positioned at any location on metal gasket bellows seal 300, however, a weld on a leg of metal gasket bellows seal 300 may be preferable to a weld at another location.

    [0053] In various embodiments, first location 428 may be positioned a first distance 434 from outer diameter edge 418. First distance 434 may be between 30 percent (30%) and 70% of a second distance 436 between outer diameter edge 418 and inner diameter edge 420, may be between 40% and 60% of second distance 436, may be between 45% and 55% of second distance 436, or may be about 50% of second distance 436. Where used in this context only, about refers to the referenced value plus or minus 3% of the referenced value. As distance 434 approaches 50% of distance 436, weld 426 may be subjected to less stress.

    [0054] Turning now to FIG. 5A, an axial view of metal gasket bellows seal 300 illustrates features of a slip joint 500. In particular, first ply 400 includes a first ply first end 502 and a first ply second end 504. First ply first end 502 and first ply second end 504 are separated by a first gap 509 having a distance 510. Likewise, second ply 402 includes a second ply first end 506 and a second ply second end 508. Second ply first end 506 and second ply second end 508 are separated by a second gap 511 having a distance 512. Slip joint 500 is defined by the overlap of first ply first end 502 and second ply second end 508.

    [0055] First gap 509 and second gap 511 allow movement of first ply 400 relative to second ply 402. Referring to FIGS. 3, 5A, and 5B, during operation of high pressure turbine section 34, a diameter 550 of metal gasket bellows seal 300 may vary based on relative movement of vane 202 and BOAS 208, as well as pressures within high pressure turbine section 34. First gap 509 and second gap 511 desirably allow this change in diameter 550 of metal gasket bellows seal 300. An overlap 514 of first ply 400 and second ply 402 further allows the change in diameter 550 of metal gasket bellows seal 300. Thus, it is undesirable for first ply 400 to be welded to second ply 402 at slip joint 500.

    [0056] According to the invention, the first location is at a location between 150 degrees and 210 degrees from slip joint 500. The first location may be at a location between 160 degrees and 200 degrees from slip joint 500, between 170 degrees and 190 degrees from slip joint 500, or about 180 degrees from slip joint 500. Where used in this context only, about refers to the referenced value plus or minus 3% of the referenced value. By placing weld 426 at first location 428 that is 180 degrees from slip joint 500, any relative movement between first ply 400 and second ply 402 at locations other than slip joint 500 is reduced. Stated differently, relative growth on either side of weld 426 will be approximately the same because each side will have a similar amount of material allowed to expand. This may be desirable when first ply 400 includes a different material than second ply 402, as first ply 400 may include a different coefficient of thermal expansion than second ply 402.

    [0057] In various embodiments and referring to FIGS. 1, 4, 5A, and 5B, metal gasket bellows seal 300 may be manufactured in a first location and at least a portion of gas turbine engine 2 that includes metal gasket bellows seal 300 may be assembled in a second location that is different than the first location. In that regard, first ply first end 502 and first ply second end 504 may move relative to each other during transportation. Likewise, second ply first end 506 and second ply second end 508 may move relative to each other during transportation or handling. Thus, diameter 550 of metal gasket bellows seal 300 may be undesirably changed during transportation.

    [0058] In order to reduce the likelihood of a metal gasket bellows seal being inadvertently adjusted during transportation and referring to FIGS. 6, 7A, and 7B, a metal gasket bellows seal 601 may have a first ply 600, a second ply 602, and adhesive 626 at a location 628 along a slip joint 700. Metal gasket bellows seal 601 may have an inner diameter edge 620, an outer diameter edge 618, a first axial end 622, and a second axial end 624. In various embodiments, first axial end 622 may be forward of second axial end 624 and, in various embodiments, first axial end 622 may be aft of second axial end 624.

    [0059] In various embodiments, adhesive 626 may be applied after first ply 600 and second ply 602 have been placed together. In that regard, location 628 may be at outer diameter edge 618 of first axial end 622 or second axial end 624. In various embodiments, adhesive 626 may only be applied at one location of metal gasket bellows seal 601. In various embodiments, adhesive 636 may comprise one or more glues, epoxies, resins, and/or other suitable materials for adhering two surfaces together.

    [0060] Referring now to FIGS. 7A and 7B, first ply 600 may have a first ply first end 702 and a first ply second end 704. First ply first end 702 and first ply second end 704 may be separated by a gap 709 having a distance 710. Likewise, second ply 602 may have a second ply first end 706 and a second ply second end 708. Second ply first end 706 and second ply second end 708 may be separated by a gap 711 having a distance 712. Distance 710 and distance 712 may have the same value, may have similar values, or may have different values.

    [0061] Slip joint 700 is defined as the circumferential overlap of first ply first end 702 and second ply second end 708. Slip joint 700 may have a distance 714. In various embodiments, distance 714 may be between 1.27 millimeters, mm (0.05 inches) and 50.8 mm (2 inches), or between 10.2 mm (0.4 inches) and 25.4 mm (1 inch), or between 12.7 mm (0.5 inches) and 25.4 mm (1 inch).

    [0062] FIG. 7A illustrates that a location 628 where adhesive 626 is applied is at outer diameter edge 618 of slip joint 700. In various embodiments, adhesive 626 may be applied at inner diameter edge 620 of slip joint 700 or at any other location of slip joint 700.

    [0063] Because it is desirable for first ply first end 702 and first ply second end 704 to be able to move relative to each other during engine operation, and for second ply first end 706 and second ply second end 708 to be able to move relative to each other during use, it is undesirable for adhesive 626 to resist movement of first ply 600 relative to second ply 602 during use of metal gasket bellows seal 601. Because metal gasket bellows seal 601 may be used in a gas turbine engine such as gas turbine engine 2 of FIG. 1, metal gasket bellows seal 601 may be exposed to relatively high temperatures. In that regard, adhesive 626 may melt and change to a gaseous state at a temperature that is less than an operating temperature of the environment of metal gasket bellows seal 601. Stated differently, adhesive 626 may have a melting temperature that is less than an operating temperature of the environment of metal gasket bellows seal 601.

    [0064] Referring to FIGS. 1 and 7A, metal gasket bellows seal 601 may be used in any portion of gas turbine engine 2, such as compressor section 6, combustor section 8, or turbine section 10. For example, metal gasket bellows seal 601 may be used in high pressure turbine section 34 of gas turbine engine 2. In that regard, metal gasket bellows seal 601 may be exposed to temperatures between 427°C and 649°C (800 degrees Fahrenheit and 1500 degrees Fahrenheit). When used in this type of environment, adhesive 626 may have a melting temperature that is between 204°C and 316°C (400 degrees Fahrenheit and 600 degrees Fahrenheit). Thus, when gas turbine engine two is first initialized, such as during a "green run," temperatures within high pressure turbine section 34 will exceed the melting temperature of adhesive 626, thus causing adhesive 626 to melt, allowing movement of first ply 600 relative to second ply 602 at slip joint 700. A "green run" may be a first initialization of gas turbine engine 2. Furthermore, if metal gasket bellows seal 601 is used in high pressure compressor section 34, temperatures may be sufficiently great to vaporize most adhesives prior to relative motion of any components being desirable.

    [0065] Turning now to FIG. 8, a method 800 for manufacturing a gas turbine engine is shown. In block 802, a metal gasket bellows seal is formed. The metal gasket bellows seal may include any number of plies.

    [0066] In block 804, the first ply may be attached to the second ply at the slip joint. For example, adhesive may be placed on the slip joint at a location at which it will contact the first ply and the second ply and resist movement of the first ply relative to the second ply.

    [0067] In block 806, the metal gasket bellows seal may be transported to a facility at which the gas turbine engine will be manufactured and/or assembled. The attachment at the slip joint via adhesive may prevent a diameter of the metal gasket bellows seal from changing during this transportation.

    [0068] In block 808, the gas turbine engine may be assembled. This assembly may include placing the metal gasket bellows seal in place within a turbine section or a compressor section of the gas turbine engine.

    [0069] In block 810, the gas turbine engine may be initialized during a green run. As the environment of the metal gasket bellows seal increases in temperature, the adhesive may melt, thus allowing the first ply to move relative to the second ply as intended by the slip joint.

    [0070] While the disclosure is described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the disclosure. In addition, different modifications may be made to adapt the teachings of the disclosure to particular situations or materials, without departing from the essential scope thereof. The disclosure is thus not limited to the particular examples disclosed herein, but includes all embodiments falling within the scope of the appended claims.

    [0071] Benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the disclosure. The scope of the disclosure is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean "one and only one" unless explicitly so stated, but rather "one or more." Moreover, where a phrase similar to "at least one of a, b, or c" is used in the claims, it is intended that the phrase be interpreted to mean that a alone may be present in an embodiment, b alone may be present in an embodiment, c alone may be present in an embodiment, or that any combination of the elements a, b and c may be present in a single embodiment; for example, a and b, a and c, b and c, or a and b and c. Different cross-hatching is used throughout the figures to denote different parts but not necessarily to denote the same or different materials.

    [0072] Systems, methods and apparatus are provided herein. In the detailed description herein, references to "one embodiment", "an embodiment", "an example embodiment", etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments.

    [0073] Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. As used herein, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.


    Claims

    1. A metal gasket bellows seal (300) comprising:

    a first ply (400) having a first ply first end (502) and a first ply second end (504) separated by a first distance (509);

    a second ply (402) having a second ply first end (506) and a second ply second end (508) separated by a second distance (511); and

    a slip joint (500) forming an area of intentional slip, the slip joint (500) formed by an overlap of the first ply first end (502) and the second ply second end (508),

    characterised in that:
    the second ply (402) is coupled to the first ply (400) at a first location (428) via spot joining to form a weld (426), wherein the first location (428) is positioned between 150 degrees and 210 degrees from the slip joint (500) such that relative growth on either side of the weld (426) is approximately the same because each side will have a similar amount of material allowed to expand.


     
    2. The metal gasket bellows seal (300) of claim 1, wherein the second ply (402) is coupled to the first ply (400) at multiple locations (428).
     
    3. The metal gasket bellows seal (300) of claim 1 or 2, wherein the spot joining includes at least one of resistance welding, laser welding, electron beam welding, gas tungsten arc welding, metal inert gas welding, or brazing.
     
    4. The metal gasket bellows seal (300) of any preceding claim, further comprising adhesive (626) coupled to the first ply (400) and the second ply (402) at the slip joint (500).
     
    5. The metal gasket bellows seal (300) of any preceding claim, wherein the first location (428) is positioned on a first leg (404) of the metal gasket bellows seal (300), optionally wherein the first location (428) is positioned between an inner diameter edge (420) of the metal gasket bellows seal (300) and an outer diameter edge (418) of the metal gasket bellows seal (300), further optionally wherein the first location (428) is positioned a first distance (434) from the outer diameter edge (418) of the metal gasket bellows seal (300) that is between 40 percent and 60 percent of a second distance (436) from the outer diameter edge (418) of the metal gasket bellows seal (300) to the inner diameter edge (420) of the metal gasket bellows seal (300).
     
    6. The metal gasket bellows seal (300) of claim 1, further comprising adhesive (626) coupled to the first ply (400) and the second ply (402) at the slip joint (500) to resist movement of the first ply (400) relative to the second ply (402).
     
    7. The metal gasket bellows seal (300) of claim 6, wherein the adhesive (626) is located at an outer diameter edge (418) of the metal gasket bellows seal (300) or at an inner diameter edge (420) of the metal gasket bellows seal (300).
     
    8. The metal gasket bellows seal (300) of claim 6 or 7, wherein the adhesive is configured to melt at a melting temperature that is less than an operating temperature of an environment of the metal gasket bellows seal (300), optionally wherein the operating temperature of the environment of the metal gasket bellows seal (300) is between 427°C and 649°C (800 degrees Fahrenheit and 1500 degrees Fahrenheit) and the melting temperature is between 204°C and 316°C (400 degrees Fahrenheit and 600 degrees Fahrenheit).
     
    9. The metal gasket bellows seal (300) of claim 6, 7 or 8, wherein the adhesive (626) resists an increase or decrease in a diameter of the metal gasket bellows seal (300) during at least one of transportation or handling of the metal gasket bellows seal (300).
     
    10. The metal gasket bellows seal (300) of any of claims 6 to 9, wherein the adhesive (626) is applied to the metal gasket bellows seal (300) at a single location (628).
     
    11. The metal gasket bellows seal (300) of any of claims 6 to 10, wherein the second ply (402) is coupled to the first ply (400) at a first location (428) away from the slip joint via at least one of resistance welding, laser welding or electron beam welding.
     
    12. A method for manufacturing a gas turbine engine (2), comprising:

    forming the metal gasket bellows seal (300) of any of claims 6 to 11;

    transporting the metal gasket bellows seal (300) to a location for assembly of the gas turbine engine (2); and

    assembling the metal gasket bellows seal (300) on the gas turbine engine (2).


     
    13. The method of claim 12, wherein the adhesive (626) is configured to melt at a melting temperature that is less than an operating temperature of an environment of the metal gasket bellows seal (300), optionally further comprising performing a green run of the gas turbine engine (2) to melt the adhesive.
     
    14. The method of claim 12 or 13, wherein the adhesive (626) resists an increase or a decrease of a diameter of the metal gasket bellows seal (300) during the transporting the metal gasket bellows seal (300) to the location for assembly of the gas turbine engine (2).
     
    15. The method of claim 12, 13 or 14, wherein the adhesive (626) is located at an outer diameter edge (418) of the metal gasket bellows seal (300) or at an inner diameter edge (420) of the metal gasket bellows seal (300).
     


    Ansprüche

    1. Metallische Manschettenbalgdichtung (300), umfassend:

    eine erste Lage (400), die ein erstes Ende (502) der ersten Lage und ein zweites Ende (504) der ersten Lage aufweist, die durch einen ersten Abstand (509) getrennt sind;

    eine zweite Lage (402), die ein erstes Ende (506) der zweiten Lage und ein zweites Ende (508) der zweiten Lage aufweist, die durch einen zweiten Abstand (511) getrennt sind; und

    eine Gleitfuge (500), die einen Bereich eines beabsichtigten Gleitens bildet, wobei die Gleitfuge (500) durch eine Überlappung des ersten Endes (502) der ersten Lage und des zweiten Endes (508) der zweiten Lage gebildet wird,

    dadurch gekennzeichnet, dass:
    die zweite Lage (402) mit der ersten Lage (400) an einer ersten Stelle (428) mittels Punktfügen, um eine Schweißstelle (426) auszubilden, gekoppelt ist, wobei die erste Stelle (428) zwischen 150 Grad und 210 Grad von der Gleitfuge (500) angeordnet ist, so dass ein relatives Wachstum auf jeder Seite der Schweißstelle (426) annähernd gleich ist, weil jede Seite eine ähnliche Menge Material aufweist, das sich ausdehnen kann.


     
    2. Metallische Manschettenbalgdichtung (300) nach Anspruch 1, wobei die zweite Lage (402) an die erste Lage (400) an mehreren Stellen (428) gekoppelt ist.
     
    3. Metallische Manschettenbalgdichtung (300) nach Anspruch 1 oder 2, wobei das Punktfügen mindestens eines aus Widerstandsschweißen, Laserschweißen, Elektronstrahlschweißen, Wolfram-Schutzgasschweißen, Metallinertgasschweißen oder Hartlöten beinhaltet.
     
    4. Metallische Manschettenbalgdichtung (300) nach einem der vorstehenden Ansprüche, ferner ein Klebemittel (626) umfassend, das an die erste Lage (400) und die zweite Lage (402) an der Gleitfuge (500) gekoppelt ist.
     
    5. Metallische Manschettenbalgdichtung (300) nach einem der vorstehenden Ansprüche, wobei die erste Stelle (428) an einem ersten Schenkel (404) der metallischen Manschettenbalgdichtung (300) angeordnet ist, optional wobei die erste Stelle (428) zwischen einer Innendurchmesserkante (420) der metallischen Manschettenbalgdichtung (300) und einer Außendurchmesserkante (418) der metallischen Manschettenbalgdichtung (300) angeordnet ist, weiter optional wobei die erste Stelle (428) in einem ersten Abstand (434) von der Außendurchmesserkante (418) der metallischen Manschettenbalgdichtung (300) angeordnet ist, der zwischen 40 Prozent und 60 Prozent eines zweiten Abstands (436) von der Außendurchmesserkante (418) der metallischen Manschettenbalgdichtung (300) zur Innendurchmesserkante (420) der metallischen Manschettenbalgdichtung (300) beträgt.
     
    6. Metallische Manschettenbalgdichtung (300) nach Anspruch 1, ferner ein Klebemittel umfassend (626), das an die erste Lage (400) und die zweite Lage (402) an der Gleitfuge (500) gekoppelt ist, um einer Bewegung der ersten Lage (400) relativ zur zweiten Lage (402) zu widerstehen.
     
    7. Metallische Manschettenbalgdichtung (300) nach Anspruch 6, wobei das Klebemittel (626) an einer Außendurchmesserkante (418) der metallischen Manschettenbalgdichtung (300) oder an einer Innendurchmesserkante (420) der metallischen Manschettenbalgdichtung (300) angeordnet ist.
     
    8. Metallische Manschettenbalgdichtung (300) nach Anspruch 6 oder 7, wobei das Klebemittel so konfiguriert ist, dass es bei einer Schmelztemperatur schmilzt, die niedriger als eine Betriebstemperatur einer Umgebung der metallischen Manschettenbalgdichtung (300) ist, optional wobei die Betriebstemperatur der Umgebung der metallischen Manschettenbalgdichtung (300) zwischen 427 °C und 649 °C (800 Grad Fahrenheit und 1500 Grad Fahrenheit) beträgt und die Schmelztemperatur zwischen 204 °C und 316 °C (400 Grad Fahrenheit und 600 Grad Fahrenheit) beträgt.
     
    9. Metallische Manschettenbalgdichtung (300) nach Anspruch 6, 7 oder 8, wobei das Klebemittel (626) einer Zunahme oder Abnahme eines Durchmessers der metallischen Manschettenbalgdichtung (300) während mindestens eines aus Transport oder Handhabung der metallischen Manschettenbalgdichtung (300) widersteht.
     
    10. Metallische Manschettenbalgdichtung (300) nach einem der Ansprüche 6 bis 9, wobei das Klebemittel (626) auf die metallische Manschettenbalgdichtung (300) an einer einzelnen Stelle (628) aufgebracht wird.
     
    11. Metallische Manschettenbalgdichtung (300) nach einem der Ansprüche 6 bis 10, wobei die zweite Lage (402) an die erste Lage (400) an einer ersten Stelle (428) von der Gleitfuge entfernt mittels mindestens einem aus Widerstandsschweißen, Laserschweißen oder Elektronenstrahlschweißen gekoppelt ist.
     
    12. Verfahren zum Herstellen eines Gasturbinentriebwerks (2), umfassend:

    Ausbilden der metallischen Manschettenbalgdichtung (300) nach einem der Ansprüche 6 bis 11;

    Transportieren der metallischen Manschettenbalgdichtung (300) an eine Stelle zur Montage des Gasturbinentriebwerks (2); und

    Montieren der metallischen Manschettenbalgdichtung (300) an das Gasturbinentriebwerk (2).


     
    13. Verfahren nach Anspruch 12, wobei das Klebemittel (626) so konfiguriert ist, dass es bei einer Schmelztemperatur schmilzt, die niedriger als eine Betriebstemperatur einer Umgebung der metallischen Manschettenbalgdichtung (300) ist, optional ferner das Durchführen eines Probelaufs des Gasturbinentriebwerks (2) umfassend, um das Klebemittel zu schmelzen.
     
    14. Verfahren nach Anspruch 12 oder 13, wobei das Klebemittel (626) einer Zunahme oder Abnahme eines Durchmessers der metallischen Manschettenbalgdichtung (300) während des Transportierens der metallischen Manschettenbalgdichtung (300) zu der Stelle für die Montage des Gasturbinentriebwerks (2) widersteht.
     
    15. Verfahren nach Anspruch 12, 13 oder 14, wobei das Klebemittel (626) an einer Außendurchmesserkante (418) der metallischen Manschettenbalgdichtung (300) oder an einer Innendurchmesserkante (420) der metallischen Manschettenbalgdichtung (300) angeordnet ist.
     


    Revendications

    1. Joint d'étanchéité métallique à soufflet (300) comprenant :

    une première épaisseur (400) ayant une première extrémité de première épaisseur (502) et une seconde extrémité de première épaisseur (504) séparées par une première distance (509) ;

    une seconde épaisseur (402) ayant une première extrémité de seconde épaisseur (506) et une seconde extrémité de seconde épaisseur (508) séparées par une seconde distance (511) ; et

    un joint coulissant (500) formant une zone de coulissement intentionnel, le joint coulissant (500) étant formé par un chevauchement de la première extrémité de première épaisseur (502) et de la seconde extrémité de seconde épaisseur (508),

    caractérisé en ce que :
    la seconde épaisseur (402) est couplée à la première épaisseur (400) au niveau d'un premier emplacement (428) par l'intermédiaire d'une jonction par points pour former une soudure (426), dans lequel le premier emplacement (428) est positionné entre 150 degrés et 210 degrés par rapport au joint coulissant (500) de sorte que la croissance relative de chaque côté de la soudure (426) est approximativement la même parce que chaque côté aura une quantité de matériau similaire autorisée à se dilater.


     
    2. Joint d'étanchéité métallique à soufflet (300) selon la revendication 1, dans lequel la seconde épaisseur (402) est couplée à la première épaisseur (400) au niveau de plusieurs emplacements (428).
     
    3. Joint d'étanchéité métallique à soufflet (300) selon la revendication 1 ou 2, dans lequel la jonction par points comporte au moins un parmi du soudage par résistance, du soudage au laser, du soudage par faisceau d'électrons, du soudage à l'arc au gaz tungstène, du soudage au gaz inerte métallique ou du brasage.
     
    4. Joint d'étanchéité métallique à soufflet (300) selon une quelconque revendication précédente, comprenant en outre un adhésif (626) couplé à la première épaisseur (400) et à la seconde épaisseur (402) au niveau du joint coulissant (500).
     
    5. Joint d'étanchéité métallique à soufflet (300) selon une quelconque revendication précédente, dans lequel le premier emplacement (428) est positionné sur une première jambe (404) du joint d'étanchéité métallique à soufflet (300), éventuellement dans lequel le premier emplacement (428) est positionné entre un bord de diamètre intérieur (420) du joint d'étanchéité métallique à soufflet (300) et un bord de diamètre extérieur (418) du joint d'étanchéité métallique à soufflet (300), en outre éventuellement dans lequel le premier emplacement (428) est positionné à une première distance (434) du bord de diamètre extérieur (418) du joint d'étanchéité métallique à soufflet (300) qui est entre 40 pour cent et 60 pour cent d'une seconde distance (436) du bord de diamètre extérieur (418) du joint d'étanchéité métallique à soufflet (300) au bord de diamètre intérieur (420) du joint d'étanchéité métallique à soufflet (300).
     
    6. Joint d'étanchéité métallique à soufflet (300) selon la revendication 1, comprenant en outre un adhésif (626) couplé à la première épaisseur (400) et à la seconde épaisseur (402) au niveau du joint coulissant (500) pour résister à un mouvement de la première épaisseur (400) par rapport à la seconde épaisseur (402) .
     
    7. Joint d'étanchéité métallique à soufflet (300) selon la revendication 6, dans lequel l'adhésif (626) est situé au niveau d'un bord de diamètre extérieur (418) du joint d'étanchéité métallique à soufflet (300) ou au niveau d'un bord de diamètre intérieur (420) du joint d'étanchéité métallique à soufflet (300) .
     
    8. Joint d'étanchéité métallique à soufflet (300) selon la revendication 6 ou 7, dans lequel l'adhésif est conçu pour fondre à une température de fusion qui est inférieure à une température de fonctionnement d'un environnement du joint d'étanchéité métallique à soufflet (300), éventuellement dans lequel la température de fonctionnement de l'environnement du joint d'étanchéité métallique à soufflet (300) est comprise entre 427 °C et 649 °C (800 degrés Fahrenheit et 1 500 degrés Fahrenheit) et la température de fusion est comprise entre 204 °C et 316 °C (400 degrés Fahrenheit et 600 degrés Fahrenheit).
     
    9. Joint d'étanchéité métallique à soufflet (300) selon la revendication 6, 7 ou 8, dans lequel l'adhésif (626) résiste à une augmentation ou à une diminution d'un diamètre du joint d'étanchéité métallique à soufflet (300) pendant au moins un du transport ou de la manipulation du joint d'étanchéité métallique à soufflet (300).
     
    10. Joint d'étanchéité métallique à soufflet (300) selon l'une quelconque des revendications 6 à 9, dans lequel l'adhésif (626) est appliqué sur le joint d'étanchéité métallique à soufflet (300) au niveau d'un emplacement unique (628).
     
    11. Joint d'étanchéité métallique à soufflet (300) selon l'une quelconque des revendications 6 à 10, dans lequel la seconde épaisseur (402) est couplée à la première épaisseur (400) au niveau d'un premier emplacement (428) éloigné du joint coulissant par l'intermédiaire d'au moins un du soudage par résistance, du soudage au laser ou du soudage par faisceau d'électrons.
     
    12. Procédé de fabrication d'un moteur à turbine à gaz (2), comprenant :

    la formation du joint d'étanchéité métallique à soufflet (300) selon l'une quelconque des revendications 6 à 11 ;

    le transport du joint d'étanchéité métallique à soufflet (300) jusqu'à un emplacement pour l'assemblage du moteur à turbine à gaz (2) ; et

    l'assemblage du joint d'étanchéité métallique à soufflet (300) sur le moteur à turbine à gaz (2).


     
    13. Procédé selon la revendication 12, dans lequel l'adhésif (626) est conçu pour fondre à une température de fusion qui est inférieure à une température de fonctionnement d'un environnement du joint d'étanchéité métallique à soufflet (300), comprenant en outre éventuellement l'exécution d'un cycle vert du moteur à turbine à gaz (2) pour faire fondre l'adhésif.
     
    14. Procédé selon la revendication 12 ou 13, dans lequel l'adhésif (626) résiste à une augmentation ou à une diminution d'un diamètre du joint d'étanchéité métallique à soufflet (300) pendant le transport du joint d'étanchéité métallique à soufflet (300) jusqu'à l'emplacement pour l'assemblage du moteur à turbine à gaz (2).
     
    15. Procédé selon la revendication 12, 13 ou 14, dans lequel l'adhésif (626) est situé au niveau d'un bord de diamètre extérieur (418) du joint d'étanchéité métallique à soufflet (300) ou au niveau d'un bord de diamètre intérieur (420) du joint d'étanchéité métallique à soufflet (300).
     




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    Cited references

    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