Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22C—FOUNDRY MOULDING
  • B22C9/00—Moulds or cores; Moulding processes
  • B22C9/02—Sand moulds or like moulds for shaped castings
  • B22C9/04—Use of lost patterns
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22C—FOUNDRY MOULDING
  • B22C9/00—Moulds or cores; Moulding processes
  • B22C9/08—Features with respect to supply of molten metal, e.g. ingates, circular gates, skim gates
  • B22C9/082—Sprues, pouring cups
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22C—FOUNDRY MOULDING
  • B22C9/00—Moulds or cores; Moulding processes
  • B22C9/10—Cores; Manufacture or installation of cores
  • B22C9/108—Installation of cores
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D23/00—Casting processes not provided for in groups B22D1/00 - B22D21/00
• • 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
  • F01D5/02—Blade-carrying members, e.g. rotors
  • F01D5/08—Heating, heat-insulating or cooling means
  • F01D5/081—Cooling fluid being directed on the side of the rotor disc or at the roots of the blades
• • 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
  • F01D5/30—Fixing blades to rotors; Blade roots ; Blade spacers
  • F01D5/3007—Fixing blades to rotors; Blade roots ; Blade spacers of axial insertion type
• • 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
  • F05D2230/20—Manufacture essentially without removing material
  • F05D2230/21—Manufacture essentially without removing material by casting

Definitions

• the invention relates to a casting apparatus for producing a turbine blade of a gas turbine according to the preamble of claim 1. Furthermore, the invention relates to a turbine blade according to the preamble of claim 6.
• Casting devices also called casting devices, for producing a turbine blade of a gas turbine are known from the prior art for the longest time.
• a casting apparatus comprises a plurality of grape-like shell molds for the simultaneous casting off of a plurality of turbine blades. Each mold shell is hollow, wherein the cavity is the negative mold of the produced
• turbine blades Since turbine blades, in particular the blades of front turbine stages, usually have to be cooled, these are also hollow.
• a cooling medium usually cooling air
• the supply of cooling air takes place via arranged in the blade root openings, which are in flow communication with the cavity or the cavities of the rotor blade.
• the mold shell for producing such a turbine blade generally comprises one or more casting cores, which are arranged in the cavity of the casting apparatus. The casting cores, after their removal in the cast turbine blade, leave the cavities through which the coolant flows during operation of the gas turbine.
• the casting device has at least one inlet channel, usually called a feeder, through which the casting material can be fed into the cavity of the shell mold during casting of the rotor blade. Consequently, the inlet channel opens with its inlet opening in that surface which limits the cavity of the mold shell.
• a feeder usually called a feeder
• the object of the invention is therefore to provide a
• the object directed to the casting device is achieved with a casting device designed according to the features of patent claim 1.
• the task relating to the turbine blade is achieved with a turbine blade formed according to claim 5.
• the invention is based on the finding that the formation of cracks during the solidification of the melt in the walls of the cooling channels in the blade-root-side region of the turbine blade is production-related.
• turbine blades are cast in a standing position by default, with the cavity in the mold shell being formed such that the negative mold of the blade of the turbine blade is formed at the bottom and above that the platform and the blade root.
• top and bottom refer to the
• the invention proposes that the feed of hot liquid casting material into the cavity of the mold shell when casting the turbine blade now has to be done so that it does not occur directly on casting cores. According to the casting material is now freely and undisturbed flow into the cavity and on the shell mold bottom, which forms the blade tip impinge.
• the cast cores are rod-shaped at least in the section of the blade root, their off-center placement in the shell results in the openings of cooling channels in the blade root of the turbine blade also being arranged off-center, relative to the generally symmetrical outer contour of the blade root.
• the symmetry is here on the in the Cross-section fir-tree-shaped or hammer-shaped contour of the blade base related.
• the surface of the shell mold has a contour for the blade root of the turbine blade, which is mirror-inverted along a blade root center.
• the contour is fir tree-shaped or hammer-shaped.
• the inlet channel is centered and one of the casting cores is arranged eccentrically, at least in the region of the inlet opening, both with reference to a blade root center, which by definition is located centrally between the lateral corrugated surfaces or contours of the blade root. Due to the eccentric arrangement of the casting cores and the blade root to be held compactly, it is necessary that the cross-sectional area of the previous casting core is divided into two casting cores. By dividing the previous, centrally placed cooling channels in each case two parallel eccentrically positioned cooling channels, the required for the cooling air cross-sectional area can be further maintained, however, the former
• Turbine blade are specified in the subclaims.
• the inlet channel opens into that part of the surface of the cavity of the mold shell, which forms the negative of the end face of the blade root of the turbine blade.
• This makes it possible to form a sufficiently large inlet channel.
• a falling cast of turbine blades with the blade root on top allows the casting of turbine blades whose largest volume, vane root, finally solidifies. Possibly. Shrinkage of the casting material occurring during solidification can be compensated by the inflow of molten casting material from the casting area. In addition, so that a compact casting device can be specified.
• the cores furthest away from the inlet opening may also be in the imaginary extension of the inlet channel in the event that the casting material flowing into the cavity does not reach them.
• FIG. 1 shows a perspective view of a casting apparatus with therein according to the invention arranged casting cores
• FIG. 2 shows a perspective view of a turbine blade according to the invention for a gas turbine.
• the casting apparatus 10 comprises at least one mold shell 12 with a cavity 14.
• the cavity 14 is bounded by a surface 16, which is the negative mold of the turbine blade to be produced.
• a total of six casting cores 18 are arranged in the cavity 14 .
• the casting cores 18 are always arranged in pairs. In total there are three pairs of cores.
• an inlet channel 20 is provided in the mold shell 12 for the filling of the liquid casting material. Its inlet opening 22 opens in the surface 16, which limits the cavity 14.
• the cavity 14 is formed in the mold shell 12 such that the negative mold of the airfoil tip of the turbine blade is located at the bottom.
• the overlying portion of the surface forms the negative of the airfoil blade.
• the part of the surface is contoured so that the negative mold of the platform of the turbine blade is formed. Subsequently, and thus arranged at the top opposite the horizontal plane, the remaining part of the surface 16 forms the contour of the blade root.
• the inlet channel 20 opens with its inlet opening 22 in that part of the surface which an end face of the Pretail pretends.
• the inlet channel 20 has a straight longitudinal extension immediately upstream of the inlet opening 22 in the illustrated casting device.
• the longitudinal extent of the inlet channel 20 extends approximately parallel or slightly inclined relative to the horizontal plane.
• the casting cores 18 are not completely shown in FIG. In FIG. 1, only those sections of the casting cores 18 are shown which are arranged in the uppermost part of the cavity 14, which predetermines the negative shape of the blade root.
• the shape, contour and type of the casting cores 18 in the platform-side region or in the blade-side region is not of further interest to the invention and can therefore be arbitrarily, for example meander-shaped, rectilinear or even slightly curved.
• the respective cooling channels can also be partially recombined.
• Each casting pair of cores 18 are spaced from one another.
• the existing between them distance A is so large that hot, liquid cast material does not hit directly on the casting cores 18 when filling the cavity 14.
• the hot casting material fed into the cavity 14 flows between two immediately adjacent casting cores 18. So it should be the contact between inflowing liquid casting material and Gusskernober Design in the foot as possible avoided.
• casting core areas are avoided with locally elevated temperature.
• the locally increased core temperature was the cause of prior art cracking phenomena on the walls of cooling passages of turbine blades.
• the imaginary extension of the longitudinal extent of the inlet channel 20 thus extends into the free area between the two casting cores 18 of a casting core pair.
• the imaginary extension of the inlet channel is completely free of casting cores 18.
• Inlet channel 20 are positioned. However, this presupposes that the range of the inflowing hot casting material is not so far that the inflow jet can hit them.
• FIG. 2 shows a perspective view of a turbine blade 30, which was produced by the casting device according to FIG.
• the turbine blade 30 has a blade root 32 contoured in the manner of a fir tree in longitudinal section, on which a platform 34 is arranged.
• the platform 34 is adjoined by an aerodynamically curved airfoil 36 which terminates at a freestanding airfoil tip 38.
• the turbine blade 30 thus extends along a longitudinal axis 40 from the blade root 32 to
• the longitudinal axis 40 is arranged such that it extends centrally or symmetrically to the contour of the fir-tree-shaped blade root 32.
• the blade root 32 has on its side facing away from the blade 36, transversely to the longitudinal axis 40 extending surface, also called bottom 42, a plurality of openings 44, which remain when the casting cores 18 have been removed from the cast turbine blade 30.
• the openings 44 are arranged on both sides of the blade root center, which is defined in cross section by the longitudinal axis 40 and also lies centrally between the lateral, corrugated surfaces of the blade root. They lie in two rows, each with three openings 44.
• the openings 44 are used for introduction a coolant into the interior of the turbine blade 30. Each opening 44 forms an end of a cooling channel of the turbine blade 30 from. Its course in the interior of the turbine blade 30 is of no importance to the invention.
• the invention prevents uneven local overheating of the casting cores 18 in the vicinity of the inlet during filling of the cavity 14. At the same time, a better filling can take place since casting cores 18 no longer block the inlet opening 22. A collision of inflowing hot casting material with casting cores 18 is prevented by the use of the invention. In addition, the solidification can be further improved by the unobstructed flow of hot cast material (food) from the feeds, which reduces remaining residual stress or residual stress and avoids the formation of cracks.
• the invention relates to a casting apparatus 10 for producing a turbine blade 30 of a gas turbine, in which the mold shell 12, its inlet and the casting cores 18 disposed therein are aligned with each other such that a casting material flowing into the cavity 14 of the shell mold 12 does not impinge on casting cores 18 directly. This will become so-called hotter areas

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Turbine Rotor Nozzle Sealing (AREA)
• Molds, Cores, And Manufacturing Methods Thereof (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=40688452

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (4)

Citations (4)

Family Cites Families (4)

• 2009
  • 2009-04-20 EP EP09005533A patent/EP2243574A1/de not_active Withdrawn
• 2010
  • 2010-04-15 US US13/265,185 patent/US20120039718A1/en not_active Abandoned
  • 2010-04-15 WO PCT/EP2010/054930 patent/WO2010121939A1/de active Application Filing
  • 2010-04-15 CN CN2010800275199A patent/CN102458715A/zh active Pending
  • 2010-04-15 EP EP10713950A patent/EP2421666A1/de not_active Withdrawn

Patent Citations (4)

Also Published As

Similar Documents

Legal Events