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
  • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
  • F01D5/12—Blades
  • F01D5/22—Blade-to-blade connections, e.g. for damping vibrations
  • F01D5/225—Blade-to-blade connections, e.g. for damping vibrations by shrouding
• • 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
  • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
  • F01D5/12—Blades
  • F01D5/14—Form or construction
• • 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
  • F05D2240/20—Rotors
  • F05D2240/30—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
• • 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
  • F05D2250/00—Geometry
  • F05D2250/70—Shape
  • F05D2250/71—Shape curved
  • F05D2250/712—Shape curved concave

Definitions

• the present invention relates to a turbine blade for a turbomachine, such as for example an aircraft turbojet.
• Document FR 2 970 999 in the name of the Applicant discloses a bladed turbine wheel comprising a turbine disk on which blades 1 are mounted.
• Each blade 1 extends radially and comprises a foot 2 radially internal, mounted in a disc cavity, a profiled blade 3, separated from the foot 2 by a radially internal platform 4.
• a radially external platform 5 extends from the radially external end of the blade 3.
• the radially external platform 5 comprises wipers 6 extending radially outwards which cooperate with an abradable material so as to form a labyrinth seal.
• the external platform 5 has an axially upstream end 7 and an axially downstream end 8 located respectively upstream and downstream of the leading edge 9 and the trailing edge 10 of the blade 3.
• the invention particularly aims to provide a simple, effective and economical solution to this problem.
• the invention relates to a turbine blade for a turbomachine intended to extend around an axis of the turbomachine, the blade comprising a blade extending radially with respect to the axis between a radially internal platform and a radially external platform, the blade comprising an axially upstream leading edge and an axially downstream trailing edge, a radially external platform comprising an upstream end and a downstream end, the radially external platform comprising at minus a wiper extending radially outwards, characterized in that the radially external end of the leading edge of the blade and / or of the trailing edge of the blade extending axially upstream relative to the upstream end of the platform and / or respectively downstream relative to the downstream end of the platform, and in that the blade has at least one partition extending radially outwards from the end radially external to the blade, and axially between the leading edge and the upstream end
• a partition extending radially outward and extending axially, that is to say along the axis of the turbine, between the leading edge of the 'blade and the upstream end of the platform and / or respectively between the trailing edge and the downstream end of the platform, constitutes at least in part an obstacle to air recirculation. Since these recirculations generate aerodynamic losses, such partitions also make it possible to improve the efficiency of the turbine.
• the partition may extend axially between the leading edge and an upstream surface of the wiper and / or respectively between the trailing edge and a downstream surface of the wiper.
• Such a partition makes it possible to prevent any recirculation of air radially outside the external platform.
• the partition can extend radially outward substantially up to the radially outer end of the wiper.
• the partition makes it possible to avoid recirculation of air all along the wiper which ensures, in cooperation with the abradable material, the seal at an air passage.
• the partition may extend radially outwards over only part of the radial dimension of the wiper.
• the radial distance between the radially outer end of the partition and the radially outer end of the wiper is for example between 1 and 10 mm.
• the partition can extend in a direction forming an angle with the radial direction.
• Such an inclination of the partition makes it possible to improve the position of the partition so that it opposes the direction of air recirculation from the lower surface to the upper surface.
• the angle is for example between 30 ° and 60 °.
• the partition may include an upstream and / or respectively downstream end edge, rectilinear and forming an angle with the radial direction.
• the angle is for example between 0 ° and 60 °.
• the wiper can extend along a plane, at least part of the partition extending perpendicular to the plane of the wiper.
• the partition extends partly perpendicular to the wiper.
• the wiper can extend along a plane, at least part of the partition extending along a plane forming an angle with the axis of the turbomachine.
• the axis of the turbomachine corresponds to the axis of the rotor on which the blades are fixed.
• the partition is thus inclined in the direction of the direction of rotation of the blade, so as to form a deflector for the air flow. Such a position thus effectively limits the recirculation of air from the lower surface to the upper surface.
• Said angle is for example between 30 ° and 60 °.
• the partition can be curved, for example concave viewed from the lower surface of the blade.
• the invention also relates to a turbomachine turbine comprising a bladed wheel comprising turbine blades as described above.
• the invention also relates to a turbomachine, such as for example an aircraft turbojet, characterized in that it comprises such a turbine.
• FIG. 1 is a schematic view of a turbine blade of the prior art
• FIG. 2 is a schematic view of an example of a turbine blade platform according to an embodiment of the invention.
• FIGS. 3A to 4B are perspective views illustrating part of a blade according to different embodiments of the invention. DETAILED DESCRIPTION
• upstream and downstream are defined with respect to the direction of flow of the gases in the turbomachine, in particular in the secondary stream.
• radial and axial are defined relative to the axis of the turbine wheel. Each turbine blade extends radially outward from the disc of the turbine wheel, the axis of rotation of which extends axially.
• Figure 2 illustrates part of a turbine blade 13 for a turbomachine according to the invention.
• Several turbine blades 13 according to the invention are intended to be mounted on a disc so as to form a turbine wheel.
• the blade 13 comprises a blade 14 extending radially, and a radially external platform 15 situated at the level of the radially external end of the blade 14.
• the blade 14 comprises a leading edge 16 axially upstream and an axially downstream trailing edge (not shown).
• the platform 15 includes an upstream end 17 and a downstream end (not shown). Said platform 15 also includes wipers, namely an upstream wiper 18 and a downstream wiper 19 in the example illustrated in the figures.
• the platform 15 extends axially between the two wipers 18, 19 and is perforated with respect to the platform 5 of the prior art presented previously. Indeed, the platform 15 does not include a part extending axially beyond the wipers 18,19.
• the radially outer end 20 of the leading edge 16 of the blade 14 extends axially upstream relative to the upstream end 17 of the platform 15.
• the radially outer end of the trailing edge (not shown) of the blade 14 extends axially downstream relative to the downstream end of the platform 15.
• the blade 13 according to the invention further comprises a partition 21.
• the partition 21 is arranged radially outside the radially outer end 20 of the leading edge 16 and / or the trailing edge (not shown) of the blade. Indeed, the partition 21 extends circumferentially opposite the radially external end 20 of the blade 14.
• the partition 21 extends axially between the leading edge 16 and the upstream end 17 of the platform15, and / or respectively between the trailing edge and the downstream end of the platform- shape 15.
• the partition 21 illustrated extends axially between the leading edge 16 and an upstream surface 22 of the wiper 18. Similarly, it is conceivable that the partition 21 extends axially between the trailing edge and a surface downstream of the wiper.
• the partition 21 extends over only part of the height, that is to say the radial dimension, of the wiper 18, 19 concerned.
• the partition 21 has an end edge 23 rectilinear and forming an angle a with the radial direction or the radial plane.
• the angle a is for example between 30 ° and 90 °.
• the angle a is inscribed in a plane having for normal the axial direction.
• the geometric shape and the positioning of the partitions 21 may vary depending on the applications.
• the partition 21, 27 extends radially outwards substantially up to the radially external end 24, 26 of the wiper 18, 19.
• the partition 21, 27 has a height substantially equivalent to that of the wiper 18, 19.
• the partition 21, 27 extends radially outwards over only part of the radial dimension of the wiper 18, 19.
• the radial distance between the radially outer end 25 of the partition 21, 27 and the radially outer end 24, 26 of the wiper 18, 19 is for example between 0.5 mm and 2 mm.
• the partition 21 located at the level of the upstream wiper 18 and the partition 27 located at the level of the downstream wiper 19 can extend in a direction forming an angle b with the radial direction.
• the angle b is for example between 0 ° and 60 °.
• the angle b is inscribed in a plane comprising the axial and radial directions.
• the downstream partition 27 extends, at least in part, along a plane forming an angle Q with the axis X of the turbomachine.
• the partition and the wiper each extend radially projecting from the blade platform.
• the partition 27 downstream is inclined in the direction of the direction of rotation of the blade R, so as to form a deflector for the air flow.
• the downstream partition 27 is inclined towards the lower surface.
• the inclination towards the lower surface is particularly interesting because it makes it more difficult to recirculate air from the lower surface to the upper surface.
• Said angle Q is for example between 0 ° and 60 °.
• the partition 21, 27 constitutes an obstacle to recirculation of air from the lower surface area to the upper surface area, and thus makes it possible to reduce the losses associated with such a recirculation. This increases the performance of the turbine, while limiting the mass of the blade 14 due to the limited dimensions of the external platform 15.

Landscapes

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

Applications Claiming Priority (2)

Publications (1)

Family

ID=63638089

Family Applications (1)

Country Status (5)

Families Citing this family (1)

Family Cites Families (8)

• 2018
  • 2018-07-24 FR FR1856854A patent/FR3084398B1/fr active Active
• 2019
  • 2019-07-23 CN CN201980047583.4A patent/CN112513424B/zh active Active
  • 2019-07-23 EP EP19791311.4A patent/EP3827160A1/de active Pending
  • 2019-07-23 US US17/262,615 patent/US11428109B2/en active Active
  • 2019-07-23 WO PCT/FR2019/051823 patent/WO2020021192A1/fr unknown

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