Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
  • F01D11/08—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
  • F01D11/005—Sealing means between non relatively rotating elements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D25/00—Component parts, details, or accessories, not provided for in, or of interest apart from, other groups
  • F01D25/24—Casings; Casing parts, e.g. diaphragms, casing fastenings
  • F01D25/246—Fastening of diaphragms or stator-rings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2230/00—Manufacture
  • F05D2230/60—Assembly methods
  • F05D2230/64—Assembly methods using positioning or alignment devices for aligning or centring, e.g. pins
  • F05D2230/642—Assembly methods using positioning or alignment devices for aligning or centring, e.g. pins using maintaining alignment while permitting differential dilatation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2240/00—Components
  • F05D2240/10—Stators
  • F05D2240/11—Shroud seal segments
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2240/00—Components
  • F05D2240/55—Seals
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2300/00—Materials; Properties thereof
  • F05D2300/10—Metals, alloys or intermetallic compounds
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2300/00—Materials; Properties thereof
  • F05D2300/60—Properties or characteristics given to material by treatment or manufacturing
  • F05D2300/603—Composites; e.g. fibre-reinforced
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T50/00—Aeronautics or air transport
  • Y02T50/60—Efficient propulsion technologies, e.g. for aircraft

Definitions

• the present invention relates to a turbine stage in a turbomachine such as a turbojet engine or a turboprop engine.
• a turbomachine essentially comprises, from upstream to downstream, a compressor, a combustion chamber and a turbine, the compressor supplying the combustion chamber with pressurized air, and the turbine receiving the hot gases coming from the combustion chamber to extract them from the combustion chamber. 'energy.
• a low-pressure turbine stage comprises a rectifier formed of an annular row of stationary vanes extending radially between two inner and outer annular platforms and a rotor wheel mounted downstream of the rectifier inside. a sectorized ring carried by a casing surrounding the turbine stage.
• Each ring sector carries on an inner face a seal cooperating with the outer peripheries of the vanes of the rotor wheel and comprises on an outer face of the attachment means on the housing formed by upstream and downstream circumferential rims.
• the upstream circumferential flange is engaged axially in an annular groove carried by an upstream annular tab of the casing and the downstream circumferential flange is clamped radially on an annular tab downstream of the casing by a C-section locking member axially engaged from downstream on the circumferential downstream flange and the downstream annular tab.
• An annular cavity is defined between the ring and the housing and defined upstream and downstream by the annular tabs of the housing.
• the upstream annular lug comprises orifices supplying this cavity with air taken from a compression stage of the turbomachine.
• each ring sector expands and deforms by taking a concave curved shape in the circumferential direction, with an outward facing concavity (decampling phenomenon).
• the formation of radial spacings between the annular tab downstream of the casing and the circumferential rims downstream of the ring sectors is observed.
• the sealing of the downstream fastener between the circumferential downstream flange of the ring and the annular downstream lug of the casing is achieved by axial prestressing of the annular lug. downstream on a radial face of the downstream circumferential flange which is opposite to the locking member.
• this assembly with cold axial prestressing is not conceivable in the case of a composite ring because of its high rigidity and low thermal expansion.
• the invention aims in particular to provide a simple, economical and effective solution to these problems, to avoid the disadvantages of the known technique.
• a turbine stage for a turbomachine comprising a paddle wheel rotating inside a sectorized ring of composite material carried by a housing, each ring sector comprising a downstream circumferential rim held in support. radial on an annular lug of the housing by a lock C, characterized in that the annular lug of the housing is engaged radially in an annular groove of the circumferential rim downstream of the ring with a cold axial clearance defined to cancel hot in operation and allow axial tight sealing of the annular lug of the housing in the annular groove of the ring sector.
• the sealing of the circumferential rim downstream of the ring in operation is ensured by the axial clamping of the upstream and downstream ends of the annular tab downstream of the casing in the annular groove, due to the greater expansion of the casing. compared to the composite ring.
• the concave curvature of the ring and its downstream circumferential rim is thus compensated for by the axial tightening of the annular lug guaranteeing the sealing of the downstream fastening of the ring.
• the annular lug of the housing comprises upstream and downstream radial faces intended to come into hot abutment on the radial flanks of the groove.
• the radial faces of the annular tab and the radial flanks of the groove retain their radial shape ensuring an annular contact between the radial faces of the ring and the radial flanks of the groove.
• the aforementioned cold axial play is of the order of one-tenth of a millimeter. It is also possible to provide an annular sealing ring housed in an annular groove of the face of the annular flange which is applied to the bottom of the annular groove of the ring sector.
• the composite material is of the ceramic matrix type and the casing is made of metallic material.
• the invention also relates to a turbomachine, such as an airplane turbojet or turboprop, comprising a high pressure turbine stage of the type described above.
• FIG. 1 is a partial schematic view in axial section of a turbine stage according to the prior art
• FIG. 2 is a schematic cross-sectional view along the cutting plane A-A shown in Figure 1;
• FIG. 3 is a partial schematic view in axial section of a cold turbine stage according to the invention and in a sectional plane not passing through a locking member;
• FIG. 4 is a partial schematic view in axial section of a hot turbine stage according to the invention and in a section plane passing through a locking member.
• FIG. 1 represents a part of a turbine stage 10 in a turbomachine which comprises a distributor stage comprising a plurality of stationary vanes and arranged upstream of a mobile wheel comprising a plurality of vanes and rotating inside a ring 12 carried by an outer casing 14.
• the ring 12 is formed of a plurality of substantially cylindrical ring sectors juxtaposed circumferentially end to end.
• Each ring sector comprises a cylindrical portion 16 bearing on its inner face a seal 18 of abradable material cooperating with the outer peripheries of the vanes of the rotor wheel.
• Each ring sector comprises two upstream annular tabs 18 and downstream hooking 20 on the casing 14.
• the outer end of the upstream annular tab 18 comprises a circumferential flange 22 facing upstream and axially engaged in an annular groove 24 downstream formed in a radial annular tab 26 of the housing.
• the outer end of the downstream annular tab 20 of the ring comprises a circumferential rim 28 oriented downstream and radially clamped on a cylindrical portion 30 of an annular tab 32 of the casing 14 by means of a locking member 32 with a section at C engaged axially on the downstream circumferential flange 28 and on the cylindrical portion 30 of the downstream annular tab 32 of the casing 14.
• Each downstream circumferential rim 20 of a ring sector comprises at least one notch aligned radially with a notch of the cylindrical portion 30 of the annular tab 32 downstream of the casing 14 and whose width is sufficient to allow the axial engagement of the locking member 32 and fixing the ring 12 on the casing 14.
• An annular cavity 34 is defined between the segmented ring 12 and the casing 14 and delimited upstream by the upstream annular tabs 18, 26 of the ring 14 and the casing 14, respectively, and downstream by the downstream annular tabs 20, 32 of the ring 12 and the casing 14, respectively.
• the upstream annular lug 26 of the casing 14 comprises orifices 36 for the passage of cooling air coming from a space that bypasses the combustion chamber, that is to say air circulating between the outer casing of the casing 14. combustion chamber and the outer wall of revolution of the combustion chamber.
• an annular sealing ring 38 is mounted in an annular groove 40 of the inner face of the cylindrical portion 30. This rod 38 is compressed radially in the annular groove 40 and on the downstream circumferential rim 28 of the ring 12.
• the inner face of the cylindrical portion 30 comprises a rib 42 engaged radially in an annular recess of the downstream circumferential flange 28 of the ring 12 to ensure the axial locking of the ring 12 on the casing 14.
• each ring sector each comprise three slots 44, 46, 48 each housing a sealing strip.
• a first slot 44 is formed in the cylindrical portion 16 of the ring 12 and extends substantially the entire length of the ring 12 and is parallel to the longitudinal axis of the ring 12.
• the other two slots 46, 48 are oblique and each formed in the upstream annular lug 18 and the downstream annular lug 20 of the ring, respectively.
• the radially inner ends of the two slits 46, 48 oblique open in a middle portion of the longitudinal slot 44 and their radial ends open at the outer faces of the upstream and downstream circumferential rims 22 and 28.
• Each slat is inserted halfway into a slot 44. , 46, 48 of a sector and for the other half in a corresponding slot facing vis-à-vis formed in a radial face of an adjacent ring sector.
• each composite ring sector deforms under the effect of heat and adopts a concave curved shape with concavity facing outwards ( Figure 2).
• the housing 14 is also deformed and has circumferential corrugations.
• the invention overcomes this problem as well as those mentioned above by forming an annular groove 50 in the outer cylindrical face of the downstream circumferential flange 52 of the ring 54, in which is engaged radially the downstream cylindrical portion 55 of the downstream annular lug 56 of the casing 14 with a cold axial play designed to cancel in operation due to the greater expansion of the casing 14 and its downstream annular lug 56 relative to the expansion of the ring 54 in composite ( Figure 3).
• the annular groove 50 comprises two upstream and downstream radial annular flanks 58 and 60.
• the downstream cylindrical portion 55 of the downstream annular lug 56 of the casing 14 comprises two upstream and downstream radial faces 64 and 64.
• the radial faces 62, 64 the downstream annular tab 56 of the casing 14 bear against the radial flanks 58, 60 of the groove 50, due to the differential expansion between the composite ring 54 and the casing 14, which ensures axial clamping of the annular tab 56 in the groove 50 and provides a sealing air ventilation circulating in the cavity 34. This axial clamping ensures at the same time the axial locking of the ring 54 on the casing 14.
• the depth of the groove 50 is chosen to be greater than the maximum radial difference R in operation between the inner face 66 of the downstream cylindrical portion 55 of the downstream lug 56 of the casing 14 and the bottom wall 68 of the groove 50, in order to permanently ensure a tight axial tight heat and avoid axial separation of the ring 54 relative to the housing 14.
• the mounting of a ring sector is achieved by inserting the upstream circumferential flange 22 of the ring 54 in the annular groove of the upstream leg 18 of the housing 14 and the downstream end of the ring is tilted outwards so that the cylindrical portion 55 is applied in the bottom of the groove 50.
• the axial play j cold facilitates the outward tilting of the ring 54 on the casing 14.
• An annular ring 38 is housed in an annular groove 40 of the face 66 of the downstream annular tab 56 of the housing which is applied to the bottom 68 of the groove 50.
• each downstream circumferential rim 52 of a ring sector comprises a notch aligned radially with a notch in the cylindrical portion of the annular downstream lug of the casing for axial mounting of the locking member 32 with a C-section.
• inter-sector sealing means are similar to those of the prior art. It will be noted, however, that according to the invention, the oblique slot of the downstream annular tab 64 of the ring 54 opens into the groove 50 and at the level of the ring 38.
• the cold axial play is of the order of 0.1 millimeter.
• the ring 54 may be made of ceramic matrix composite material resistant to high temperatures such as those in a high pressure turbine and the housing 14 is made of a metal material such as INCO or steel.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Turbine Rotor Nozzle Sealing (AREA)
• Gasket Seals (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=42331016

Family Applications (1)

Country Status (8)

Families Citing this family (12)

Family Cites Families (10)

• 2009
  • 2009-12-18 FR FR0906162A patent/FR2954400B1/fr active Active
• 2010
  • 2010-12-14 CN CN2010800579245A patent/CN102667066A/zh active Pending
  • 2010-12-14 BR BR112012010257A patent/BR112012010257A2/pt not_active IP Right Cessation
  • 2010-12-14 EP EP10809013A patent/EP2513428A1/fr not_active Withdrawn
  • 2010-12-14 RU RU2012130351/06A patent/RU2012130351A/ru unknown
  • 2010-12-14 WO PCT/FR2010/052721 patent/WO2011073570A1/fr active Application Filing
  • 2010-12-14 US US13/511,266 patent/US20120237342A1/en not_active Abandoned
  • 2010-12-14 CA CA2777370A patent/CA2777370A1/fr not_active Abandoned

Non-Patent Citations (1)

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