CA2603503C - Annular gas turbine engine case and method of manufacturing - Google Patents
Annular gas turbine engine case and method of manufacturing Download PDFInfo
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- CA2603503C CA2603503C CA 2603503 CA2603503A CA2603503C CA 2603503 C CA2603503 C CA 2603503C CA 2603503 CA2603503 CA 2603503 CA 2603503 A CA2603503 A CA 2603503A CA 2603503 C CA2603503 C CA 2603503C
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- case
- gas turbine
- turbine engine
- flowformed
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Classifications
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- 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
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C24/00—Coating starting from inorganic powder
- C23C24/08—Coating starting from inorganic powder by application of heat or pressure and heat
- C23C24/10—Coating starting from inorganic powder by application of heat or pressure and heat with intermediate formation of a liquid phase in the layer
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C30/00—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process
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- 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
- F05D2230/23—Manufacture essentially without removing material by permanently joining parts together
- F05D2230/232—Manufacture essentially without removing material by permanently joining parts together by welding
- F05D2230/237—Brazing
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- 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
- F05D2230/26—Manufacture essentially without removing material by rolling
-
- 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
- F05D2230/30—Manufacture with deposition of material
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- 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
- F05D2230/40—Heat treatment
-
- 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
- F05D2230/40—Heat treatment
- F05D2230/41—Hardening; Annealing
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- 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
Abstract
The method for manufacturing an annular gas turbine engine case comprises flowforming at least one section of a preform and then adding at least one additional element on the at least one flowformed section.
Description
ANNULAR GAS TURBINE ENGINE CASE AND METHOD OF
MANUFACTURING
TECHNICAL FIELD
The invention relates to an annular gas turbine engine case and a method of manufacturing the same.
BACKGROUND
Although unlikely, it is possible that during operation of a gas turbine engine a rotating airfoil can fail by separating from the hub or disc and being released in a radial direction. A surrounding containment structure is designed to capture the released airfoil and prevent it from leaving the engine, in either the radial or axial direction. The containment structure must be strong, and for airborne applications, lightweight. It is also desirable, of course, to provide components as cost effectively as possible. A turbofan fan case is one example of an airfoil containment structure, and a compressor or gas generator case is another example. In addition to performing a containment function, a gas generator case is also a pressure vessel.
Traditionally, a fan case is manufactured by machining a forging, but this wastes much material, and requires several steps, and therefore time. Traditionally, a gas generator case is machined out of two or three forged or sheet metal rings, provided to meet the various thickness requirements and design intents, then these rings are welded together. However, the weld joint(s) must to be located in a region away from the fragment trajectory of the impeller blade, since weld lines are not desired in containment sections of components. All these steps are time consuming and therefore increase lead-time. It is desirable to provide improved ways for manufacturing annular gas turbine engine cases in effort to reduce lead-time and manufacturing costs.
DOCSMTL. 2504394\1
MANUFACTURING
TECHNICAL FIELD
The invention relates to an annular gas turbine engine case and a method of manufacturing the same.
BACKGROUND
Although unlikely, it is possible that during operation of a gas turbine engine a rotating airfoil can fail by separating from the hub or disc and being released in a radial direction. A surrounding containment structure is designed to capture the released airfoil and prevent it from leaving the engine, in either the radial or axial direction. The containment structure must be strong, and for airborne applications, lightweight. It is also desirable, of course, to provide components as cost effectively as possible. A turbofan fan case is one example of an airfoil containment structure, and a compressor or gas generator case is another example. In addition to performing a containment function, a gas generator case is also a pressure vessel.
Traditionally, a fan case is manufactured by machining a forging, but this wastes much material, and requires several steps, and therefore time. Traditionally, a gas generator case is machined out of two or three forged or sheet metal rings, provided to meet the various thickness requirements and design intents, then these rings are welded together. However, the weld joint(s) must to be located in a region away from the fragment trajectory of the impeller blade, since weld lines are not desired in containment sections of components. All these steps are time consuming and therefore increase lead-time. It is desirable to provide improved ways for manufacturing annular gas turbine engine cases in effort to reduce lead-time and manufacturing costs.
DOCSMTL. 2504394\1
2 SUMMARY
In one aspect, the present concept provides a method of manufacturing an annular gas turbine engine case comprising: flowforming at least one section of the preform; and forming at least one additional element on the at least one flowformed section by depositing material onto the flowformed section.
In another aspect, the present concept provides a method of manufacturing an annular gas turbine engine case comprising: flowforming at least one section of the preform; and then adding at least one additional element on the at least one flowformed section by brazing.
In another aspect, the present concept provides an annular gas turbine engine case, comprising: at least one flowformed section; and at least one additional element added to the at least one section by laser deposition.
In another aspect, the present concept provides an annular gas turbine engine case, comprising: at least one flowformed section; and at least one additional element added to the at least one section by brazing.
Further details of these and other aspects will be apparent from the detailed description and figures included below.
BRIEF DESCRIPTION OF THE FIGURES
For a better understanding and to show more clearly how it may be carried into effect, reference will now be made by way of example to the accompanying figures, in which:
FIG. 1 schematically shows a generic turbofan gas turbine engine to illustrate an example of a general environment in which annular gas turbine engine cases can be used;
FIGS. 2a and 2b schematically illustrate the principles of flowforming;
In one aspect, the present concept provides a method of manufacturing an annular gas turbine engine case comprising: flowforming at least one section of the preform; and forming at least one additional element on the at least one flowformed section by depositing material onto the flowformed section.
In another aspect, the present concept provides a method of manufacturing an annular gas turbine engine case comprising: flowforming at least one section of the preform; and then adding at least one additional element on the at least one flowformed section by brazing.
In another aspect, the present concept provides an annular gas turbine engine case, comprising: at least one flowformed section; and at least one additional element added to the at least one section by laser deposition.
In another aspect, the present concept provides an annular gas turbine engine case, comprising: at least one flowformed section; and at least one additional element added to the at least one section by brazing.
Further details of these and other aspects will be apparent from the detailed description and figures included below.
BRIEF DESCRIPTION OF THE FIGURES
For a better understanding and to show more clearly how it may be carried into effect, reference will now be made by way of example to the accompanying figures, in which:
FIG. 1 schematically shows a generic turbofan gas turbine engine to illustrate an example of a general environment in which annular gas turbine engine cases can be used;
FIGS. 2a and 2b schematically illustrate the principles of flowforming;
3 FIG. 3a is a side view of an example of a gas generator case and 3b is a cross-section view of a portion of a gas generator case;
FIG. 4a is a cross-section view of a portion an example of a fan case, and FIG. 4b is an enlarged portion of an example of a fan case; and FIGS. 5a and 5b are cross-section views of portions of example cases.
DETAILED DESCRIPTION
FIG. 1 illustrates a turbofan gas turbine engine 10 of a type preferably provided for use in subsonic flight, generally comprising in serial flow communication a fan 12 through which ambient air is propelled, a fan case 13 surrounding the fan, a multistage compressor 14 for pressurizing the air, a combustor 16 in which the compressed air is mixed with fuel and ignited for generating an annular stream of hot combustion gases, a gas generator case 17 surrounding at least a portion of compressor 14 and combustor 16, and a turbine section 18 for extracting energy from the combustion gases. Fan case 13 and gas generator case 17 are preferably manufactured using flowforming techniques, as will be described further below.
As schematically shown in FIGS. 2a and 2b, flowforming generally involves applying a compressive force using rollers 20 on the outside diameter of a rotating preform 22 (also called a blank) mounted on a rotating mandrel 24.
The preform 22 is forced to flow along the mandrel 24, for instance using a set of two to four rollers 20 that move along the length of the rotating perform 22, forcing it to match the shape of the mandrel 24. The process extrudes and therefore thins or reduces the cross-sectional area of the wall thickness of the rotating perform 22, which is engineered to produce a cylindrical, conical or contoured hollow shape. The thickness of the finished part is determined by the gap that is maintained between the mandrel 24 and the rollers 20 during the process, and therefore the final thickness of the part may be controlled. This gap can be
FIG. 4a is a cross-section view of a portion an example of a fan case, and FIG. 4b is an enlarged portion of an example of a fan case; and FIGS. 5a and 5b are cross-section views of portions of example cases.
DETAILED DESCRIPTION
FIG. 1 illustrates a turbofan gas turbine engine 10 of a type preferably provided for use in subsonic flight, generally comprising in serial flow communication a fan 12 through which ambient air is propelled, a fan case 13 surrounding the fan, a multistage compressor 14 for pressurizing the air, a combustor 16 in which the compressed air is mixed with fuel and ignited for generating an annular stream of hot combustion gases, a gas generator case 17 surrounding at least a portion of compressor 14 and combustor 16, and a turbine section 18 for extracting energy from the combustion gases. Fan case 13 and gas generator case 17 are preferably manufactured using flowforming techniques, as will be described further below.
As schematically shown in FIGS. 2a and 2b, flowforming generally involves applying a compressive force using rollers 20 on the outside diameter of a rotating preform 22 (also called a blank) mounted on a rotating mandrel 24.
The preform 22 is forced to flow along the mandrel 24, for instance using a set of two to four rollers 20 that move along the length of the rotating perform 22, forcing it to match the shape of the mandrel 24. The process extrudes and therefore thins or reduces the cross-sectional area of the wall thickness of the rotating perform 22, which is engineered to produce a cylindrical, conical or contoured hollow shape. The thickness of the finished part is determined by the gap that is maintained between the mandrel 24 and the rollers 20 during the process, and therefore the final thickness of the part may be controlled. This gap can be
4 changed or remain constant anywhere along the length of the part, to thereby change or maintain part thickness, as desired.
FIGS. 3a and 3b show an example of a flowformed gas generator case 30. The case includes a rear flange portion 32, a central flowformed section 33 and a front flange portion 36. Central flowformed section 33 includes a containment portion 35 and a gas generator portion 37. As will be appreciated, the limitations of flowforming are such that the gas generator case 30 cannot be flowformed in its entirety as a single piece. Therefore, rear flange portion 32 and front flange portion 36 are joined by welds 39 to central flowformed section 33. The thickness of the central flowformed section 33 varies along the central section 33, from an area of increased thickness corresponding to containment portion 35, decreasing smoothly to a smaller thickness corresponding to a gas generator portion 37. More material is thus provided where needed for containment, and less material where not required for the pressure vessel portions. The thickness of gas generator portion 37 is designed to handle the high pressure compressor exit pressure (so-called "P3" pressure, whereas the thicker portion of containment portion 35 is sized to contain any high energy fragments from the compressor impeller blades in addition handling P3 pressure.
Central flowformed section 33 has a generally conical or cylindrical shape, to facilitate mandrel removal after flowforming. An example material is ferritic/martensitic stainless steel SS410.
A traditional way to provide a gas generator case is to machine the case out of two or three forged rings sized to meet the various thickness requirements, an then weld these rings together. Using flowforming reduces the costs significantly and reduces the number of welds, which are undesirable in high temperature and high pressure environments. Since only a section of the gas generator case 30 of this design could be flowformed, the rear flange portion 32 may be provided, for example, by outwardly bending the perform using a press, or by machining rear flange portion 32 from a ring, etc. Also, an non-axisymmetric detail 34 was later joined at the bottom of the flowformed section using a suitable method, such as welding.
The preform for the gas generator case may be obtained from any suitable process, such as deep drawing or stamping a cold rolled and annealed sheet.
FIGS. 3a and 3b show an example of a flowformed gas generator case 30. The case includes a rear flange portion 32, a central flowformed section 33 and a front flange portion 36. Central flowformed section 33 includes a containment portion 35 and a gas generator portion 37. As will be appreciated, the limitations of flowforming are such that the gas generator case 30 cannot be flowformed in its entirety as a single piece. Therefore, rear flange portion 32 and front flange portion 36 are joined by welds 39 to central flowformed section 33. The thickness of the central flowformed section 33 varies along the central section 33, from an area of increased thickness corresponding to containment portion 35, decreasing smoothly to a smaller thickness corresponding to a gas generator portion 37. More material is thus provided where needed for containment, and less material where not required for the pressure vessel portions. The thickness of gas generator portion 37 is designed to handle the high pressure compressor exit pressure (so-called "P3" pressure, whereas the thicker portion of containment portion 35 is sized to contain any high energy fragments from the compressor impeller blades in addition handling P3 pressure.
Central flowformed section 33 has a generally conical or cylindrical shape, to facilitate mandrel removal after flowforming. An example material is ferritic/martensitic stainless steel SS410.
A traditional way to provide a gas generator case is to machine the case out of two or three forged rings sized to meet the various thickness requirements, an then weld these rings together. Using flowforming reduces the costs significantly and reduces the number of welds, which are undesirable in high temperature and high pressure environments. Since only a section of the gas generator case 30 of this design could be flowformed, the rear flange portion 32 may be provided, for example, by outwardly bending the perform using a press, or by machining rear flange portion 32 from a ring, etc. Also, an non-axisymmetric detail 34 was later joined at the bottom of the flowformed section using a suitable method, such as welding.
The preform for the gas generator case may be obtained from any suitable process, such as deep drawing or stamping a cold rolled and annealed sheet.
5 Where a stamped circular blank or flat plate is used, the blank is thicker than the thickest final portion of the case. The blank is preferably cold worked to introduce compressive stresses into the material.
During the flowforming process, material is displaced by shear force over the spinning mandrel to produce a variable thickness case. The central section 33 of the case is flowformed, preferably in one pass, using a two-roller flowforming machine (not shown). Preferably, a full anneal then follows to recrystallise the microstructure.
After forming/machining and assembly, the case is preferably also hardened-tempered to give the material its final properties, including obtaining the desired microstructure and hardness.
FIG. 4a shows an example of a fan case 40. The fan case 40 is typically a containment part which is one piece and without welds in the containment zone, as welds undesirably weaken the part in containment areas, and thus are avoided. The thickness of the fan case 40 varies along the part, depending on the local resistance requirements to minimize weight and the expected trajectory of high energy fragments, as will be discussed further below. An example material used is an austenitic stainless steel with high yield strength and excellent ductility even at low temperatures, such as Nitronic 33.
At least two different areas are provided, namely a containment area 42 having a first thickness and a non-containment area 44 having a second thickness less than the first thickness, to lower the overall weight. Accordingly, the first and second average thicknesses are different. The fan case is otherwise preferably smooth and continuous, with no abrupt changes or discontinuities in shape.
Flanges 46 and 48 are provided, as discussed below.
During the flowforming process, material is displaced by shear force over the spinning mandrel to produce a variable thickness case. The central section 33 of the case is flowformed, preferably in one pass, using a two-roller flowforming machine (not shown). Preferably, a full anneal then follows to recrystallise the microstructure.
After forming/machining and assembly, the case is preferably also hardened-tempered to give the material its final properties, including obtaining the desired microstructure and hardness.
FIG. 4a shows an example of a fan case 40. The fan case 40 is typically a containment part which is one piece and without welds in the containment zone, as welds undesirably weaken the part in containment areas, and thus are avoided. The thickness of the fan case 40 varies along the part, depending on the local resistance requirements to minimize weight and the expected trajectory of high energy fragments, as will be discussed further below. An example material used is an austenitic stainless steel with high yield strength and excellent ductility even at low temperatures, such as Nitronic 33.
At least two different areas are provided, namely a containment area 42 having a first thickness and a non-containment area 44 having a second thickness less than the first thickness, to lower the overall weight. Accordingly, the first and second average thicknesses are different. The fan case is otherwise preferably smooth and continuous, with no abrupt changes or discontinuities in shape.
Flanges 46 and 48 are provided, as discussed below.
6 A circular plate is preferably flowformed to a desired thickness(es).
Preferably, suitable treatments to harden (e.g. by solid solution, etc.) and anneal the case are made after flowforming.
After flowforming, the flanges 46, 48 are provided by outwardly bending the two extremities of the flowformed shell using a suitable tool (not shown). In order to facilitate providing flanges on both ends of the same part, the fan case design includes a clearance gap "G" provided between diameter A (the outside diameter of the case 40 at the base of flange 46) and the outside diameter of the flange 48, in order to permit annular tooling T to fit over the rear flange 48 to support case 40 when bending front flange 46 into place. Thus, fan case 40 is provided within constraints on the diametes of the case at the base of flange 36 and the outside diameter of flange 38. Although not required or desired in this embodiment, flanged portions may alternately be welded to a flowformed portion of fan case 40. Referring to FIG. 4b, after bending, the case may be machined from the original thickness (outside line) to a desired final shape and thickness (inside line). Preforms used for the flowforming may be provided in any suitable manner. Although a stamped circular sheet is the desired manner, preforms may also be shaped by deep drawing, or by machining a forged or cast bar, or any other suitable manner.
Flowforming, however, can only generate axisymmetric shells or the like.
Bosses, stiffeners or welding lips cannot be provided using these techniques.
Furthermore, flanges cannot always be obtained, even after considering subsequent forming steps such as bending and rolling/necking. For these reasons, such details are preferably provided using other techniques, such as machined out of forged rings, and then attached to the flowformed shell, as will now be described.
FIG. 5a shows examples of additional elements 30, 32 added to a flowformed shell 33 of FIGS. 3a and 3b. The base metal of flowformed shell 33 is relatively thin, and so preferably heat input is limited to avoid distortion. The applicant has
Preferably, suitable treatments to harden (e.g. by solid solution, etc.) and anneal the case are made after flowforming.
After flowforming, the flanges 46, 48 are provided by outwardly bending the two extremities of the flowformed shell using a suitable tool (not shown). In order to facilitate providing flanges on both ends of the same part, the fan case design includes a clearance gap "G" provided between diameter A (the outside diameter of the case 40 at the base of flange 46) and the outside diameter of the flange 48, in order to permit annular tooling T to fit over the rear flange 48 to support case 40 when bending front flange 46 into place. Thus, fan case 40 is provided within constraints on the diametes of the case at the base of flange 36 and the outside diameter of flange 38. Although not required or desired in this embodiment, flanged portions may alternately be welded to a flowformed portion of fan case 40. Referring to FIG. 4b, after bending, the case may be machined from the original thickness (outside line) to a desired final shape and thickness (inside line). Preforms used for the flowforming may be provided in any suitable manner. Although a stamped circular sheet is the desired manner, preforms may also be shaped by deep drawing, or by machining a forged or cast bar, or any other suitable manner.
Flowforming, however, can only generate axisymmetric shells or the like.
Bosses, stiffeners or welding lips cannot be provided using these techniques.
Furthermore, flanges cannot always be obtained, even after considering subsequent forming steps such as bending and rolling/necking. For these reasons, such details are preferably provided using other techniques, such as machined out of forged rings, and then attached to the flowformed shell, as will now be described.
FIG. 5a shows examples of additional elements 30, 32 added to a flowformed shell 33 of FIGS. 3a and 3b. The base metal of flowformed shell 33 is relatively thin, and so preferably heat input is limited to avoid distortion. The applicant has
7 found that laser deposition using a powder may be used to deposit material on shell 33 which provides a compromise must be reached between precision and speed to ensure the final cost will be competitive with machining. Other processes, such as TIG deposition are possible but may not be preferred, depending on the shell thicknesses present, since too much heat may result in distortion of the shell 33. Although very high precision deposition may be used, it is currently a slow process, and therefore, in the example of FIG. 3, the added elements 50, 52 are preferably roughly deposited, and then machined to final dimensions to ensure appropriate filet radii and surface finish. Adding material by laser deposition is more economical than casting or forging and then removing unwanted material. Deposition process would eliminate material waste and welding steps.
Referring to FIG. 5b, a boss 54 are made separately and added by brazing to the flowformed shell 33. The flowformed shell is therefore kept intact where welds are not accepted. Therefore, flowforming can be a very advantageous alternative to other known techniques for the manufacturing of gas turbine case components. It permits reduced cost and weight relative to other methods, eliminates the need for axial welds, and helps reduce or eliminate the number of circumferential welds required.
The above description is meant to be exemplary only, and one skilled in the art will recognize that other changes may also be made to the embodiments described without departing from the scope of the invention disclosed as defined by the appended claims. For instance, the present invention is not limited to gas generator case and fan case components exactly as illustrated herein. Also, the gas turbine engine shown in FIG. 1 is only one example of an environment where aircraft engine components can be used. They can also be used in other kinds of gas turbine engines, such as in the gas generator cases of turboprop and turboshaft engines. The various materials and dimensions are provided only as an example. Still other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this
Referring to FIG. 5b, a boss 54 are made separately and added by brazing to the flowformed shell 33. The flowformed shell is therefore kept intact where welds are not accepted. Therefore, flowforming can be a very advantageous alternative to other known techniques for the manufacturing of gas turbine case components. It permits reduced cost and weight relative to other methods, eliminates the need for axial welds, and helps reduce or eliminate the number of circumferential welds required.
The above description is meant to be exemplary only, and one skilled in the art will recognize that other changes may also be made to the embodiments described without departing from the scope of the invention disclosed as defined by the appended claims. For instance, the present invention is not limited to gas generator case and fan case components exactly as illustrated herein. Also, the gas turbine engine shown in FIG. 1 is only one example of an environment where aircraft engine components can be used. They can also be used in other kinds of gas turbine engines, such as in the gas generator cases of turboprop and turboshaft engines. The various materials and dimensions are provided only as an example. Still other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this
8 disclosure, and such modifications are intended to fall within the appended claims.
Claims (9)
1. A method of manufacturing an annular gas turbine engine case comprising:
flowforming at least one annular section of a preform on a mandrel;
slidingly removing the annular section from the mandrel; and forming at least one outwardly extending element on an inner surface of the at least one flowformed annular section by depositing material onto the inner surface of the flowformed section.
flowforming at least one annular section of a preform on a mandrel;
slidingly removing the annular section from the mandrel; and forming at least one outwardly extending element on an inner surface of the at least one flowformed annular section by depositing material onto the inner surface of the flowformed section.
2. The method as defined in claim 1, wherein the depositing is achieved by laser deposition of powder.
3. The method as defined in claim 1, further comprising:
machining the at least one outwardly extending element formed by deposition.
machining the at least one outwardly extending element formed by deposition.
4. The method as defined in claim 1, wherein the annular gas turbine engine case is a gas generator case.
5. The method as defined in claim 1, wherein the annular gas turbine engine case is a fan case.
6. A method of manufacturing an annular gas turbine engine case comprising:
flowforming at least one annular section of a preform on a mandrel;
slidingly removing the annular section from the mandrel; and then adding at least one outwardly extending element on an inner surface of the at least one flowformed annular section by brazing.
flowforming at least one annular section of a preform on a mandrel;
slidingly removing the annular section from the mandrel; and then adding at least one outwardly extending element on an inner surface of the at least one flowformed annular section by brazing.
7. The method as defined in claim 6, further comprising:
machining the at least one outwardly extending element.
machining the at least one outwardly extending element.
8. The method as defined in claim 6, wherein the annular gas turbine engine case is a gas generator case.
9. The method as defined in claim 6, wherein the annular gas turbine engine case is a fan case.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/537,908 | 2006-10-02 | ||
US11/537,908 US20080080974A1 (en) | 2006-10-02 | 2006-10-02 | Annular gas turbine engine case and method of manufacturing |
Publications (2)
Publication Number | Publication Date |
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CA2603503A1 CA2603503A1 (en) | 2008-04-02 |
CA2603503C true CA2603503C (en) | 2015-04-07 |
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CA 2603503 Expired - Fee Related CA2603503C (en) | 2006-10-02 | 2007-09-21 | Annular gas turbine engine case and method of manufacturing |
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US (1) | US20080080974A1 (en) |
CA (1) | CA2603503C (en) |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080086882A1 (en) * | 2006-10-02 | 2008-04-17 | Andreas Eleftheriou | Annular gas turbine engine case and method of manufacturing |
US8397383B2 (en) * | 2006-10-02 | 2013-03-19 | Pratt & Whitney Canada Corp. | Annular gas turbine engine case and method of manufacturing |
US20080086881A1 (en) * | 2006-10-02 | 2008-04-17 | Andreas Eleftheriou | Annular gas turbine engine case and method of manufacturing |
CN105127686B (en) * | 2015-09-23 | 2017-09-12 | 河北赛强冶金重工机械有限公司 | A kind of withdrawal straightening machine roller preparation technology |
US20180221958A1 (en) * | 2017-02-07 | 2018-08-09 | General Electric Company | Parts and methods for producing parts using hybrid additive manufacturing techniques |
CN107931972B (en) * | 2017-11-09 | 2019-05-21 | 中国航发航空动力股份有限公司 | A kind of aero-engine front housing component machining benchmark conversion method |
CN109604950A (en) * | 2018-12-06 | 2019-04-12 | 重庆天骄航空动力有限公司 | A kind of processing method of aero-engine casing |
CN110666444B (en) * | 2019-10-19 | 2021-07-13 | 福州六和汽车零部件有限公司 | Turbine shell machining process |
Family Cites Families (8)
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DE19547903C1 (en) * | 1995-12-21 | 1997-03-20 | Mtu Muenchen Gmbh | Mfr. or repair of turbine blade tips using laser beam weld-coating and blade master alloy metal powder filler |
US6164904A (en) * | 1998-08-07 | 2000-12-26 | United Technologies Corporation | Assembly for brazing a stator component of a gas turbine engine and method brazing articles such as an abradable material to a stator of a gas turbine engine |
US6593540B1 (en) * | 2002-02-08 | 2003-07-15 | Honeywell International, Inc. | Hand held powder-fed laser fusion welding torch |
US7370467B2 (en) * | 2003-07-29 | 2008-05-13 | Pratt & Whitney Canada Corp. | Turbofan case and method of making |
US20050279630A1 (en) * | 2004-06-16 | 2005-12-22 | Dynamic Machine Works, Inc. | Tubular sputtering targets and methods of flowforming the same |
US20080086882A1 (en) * | 2006-10-02 | 2008-04-17 | Andreas Eleftheriou | Annular gas turbine engine case and method of manufacturing |
US8397383B2 (en) * | 2006-10-02 | 2013-03-19 | Pratt & Whitney Canada Corp. | Annular gas turbine engine case and method of manufacturing |
US20080086881A1 (en) * | 2006-10-02 | 2008-04-17 | Andreas Eleftheriou | Annular gas turbine engine case and method of manufacturing |
-
2006
- 2006-10-02 US US11/537,908 patent/US20080080974A1/en not_active Abandoned
-
2007
- 2007-09-21 CA CA 2603503 patent/CA2603503C/en not_active Expired - Fee Related
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US20080080974A1 (en) | 2008-04-03 |
CA2603503A1 (en) | 2008-04-02 |
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