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Researchers Submit Patent Application, "Turbine Engine Blade Or Vane Made of Composite Material, Turbine Nozzle Or Compressor Stator Incorporating...

February 20, 2014



Researchers Submit Patent Application, "Turbine Engine Blade Or Vane Made of Composite Material, Turbine Nozzle Or Compressor Stator Incorporating Such Vanes and Method of Fabricating Same", for Appro

By a News Reporter-Staff News Editor at Politics & Government Week -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors NUNEZ, ROMAIN (Martignas Sur Jalle, FR); Blanchard, Stephane (Chartrettes, FR); Renon, Guillaume (Vaux le Penil, FR); Coupe, Dominique (Le Haillan, FR); Roussille, Clement (Bordeaux, FR); Beaujard, Antoine Jean-Philippe (Moissy-Cramayel, FR); Fremont, Elric Georges Andre (Merignac, FR), filed on September 7, 2012, was made available online on February 6, 2014.

The patent's assignee is Herakles.

News editors obtained the following quote from the background information supplied by the inventors: "The invention relates to turbine engine blades or vanes made of composite material comprising fiber reinforcement densified by a matrix. The invention relates also to compressor stator segments and turbine nozzle segments incorporating such composite material vanes.

"The intended field is that of gas turbine blades or vanes for aeroengines or industrial turbines.

"Proposals have already been made to fabricate composite material blades for turbine engines. Reference may be made in particular to patent applications FR 2 939 129 and FR 2 939 130 filed jointly by Snecma and Snecma Propulsion Solide. Those applications describe in particular fabricating a turbine engine blade out of composite material comprising fiber reinforcement densified by a matrix. More precisely, the method described in those two documents and applied to fabricating a blade presents the special feature of a fiber blank that is made by three-dimensional weaving and that is shaped in order to obtain a single-piece fiber preform with a first portion forming a preform for a blade root and an airfoil, and at least one second portion forming a preform for an inner or an outer platform of the blade. Thus, once the preform has been densified, it is possible to obtain a composite material blade having fiber reinforcement constituted by the preform and densified by the matrix, and forming a single piece that has an inner or an outer platform incorporated therein.

"The blade obtained by such a method presents the drawback that its outer platform cannot incorporate both a function of providing sealing with the casing that surrounds the blades (by having wipers present) and an aerodynamic function (by having overhangs present that define the outside of gas flowpath through the turbine). Furthermore, at its root, the overhangs of the inner blade platform that is obtained by that method can break under the effect of the high levels of force to which they are subjected in operation (this force being due to the centrifugal force of rotation).

"Use of CMC materials has also been proposed for turbine nozzles, in particular in application WO 2010/146288.

"A conventional metallic turbine nozzle or compressor stator is formed of several assembled sectors, each sector comprising an inner platform, an outer platform and a plurality of airfoils extending between the inner and outer platforms and integral therewith. The inner and outer platforms delimit the gas or air flow passage in the turbine nozzle or compressor stator. On the outside, the outer platforms of the segments are formed integrally with legs allowing the mounting of the turbine nozzle or compressor stator in a casing."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "An object of the present invention is thus to mitigate such drawbacks by proposing a blade of composite material that forms a single piece having an inner and/or an outer platform incorporated therein, and in which the outer and inner platforms present the required properties. An object of the present invention is also to propose a turbomachine vane of composite material that forms a single piece having an inner and/or an outer platform incorporated therein.

"This object is achieved by a method of fabricating a turbine engine blade or vane out of composite material comprising fiber reinforcement densified by a matrix, the method comprising:

"performing three-dimensional weaving to make a single-piece fiber blank;

"shaping the fiber blank to obtain a single-piece fiber preform having a first portion forming a preform for at least a blade or vane airfoil, at least one second portion forming a preform for an inner part of a blade or vane inner platform or for an outer part of a blade or vane outer platform, and at least one third portion forming a preform for an outer part of a blade or vane inner platform or for an inner part of a blade or vane outer platform; and

"densifying the fiber preform with a matrix in order to obtain a composite material blade having fiber reinforcement constituted by the preform and densified by the matrix, and forming a single piece with an inner and/or outer platform(s) incorporated therein.

"According to an advantageous feature of the method, in the longitudinal direction corresponding to the longitudinal direction of the fiber blank that is to be fabricated, the fiber blank comprises:

"a first set of a plurality of yarn layers that are linked together to form a first portion of the blank corresponding to at least the blade or vane airfoil preform;

"a second set of a plurality of yarn layers that are linked together at least locally to form at least a second portion of the blank corresponding to the inner part of the blade or vane inner platform preform or to the outer part of the blade or vane outer platform preform; and

"a third set of a plurality of yarn layers that are linked together at least locally to form at least a third portion of the blank corresponding to the outer part of the blade or vane inner platform preform or to the inner part of the blade or vane outer platform preform;

"the yarns of the first set of yarn layers being not linked with the yarns of the second and third sets of yarn layers; and

"yarns of the second and third sets of yarn layers crossing through the first set of yarn layers at the level of the or each second portion of the fiber blank and at the level of the or each third portion of the fiber blank, respectively.

"Providing non-linked zones enables the fiber preform to be shaped without cutting linking yarns, where such cutting can reduce the mechanical strength of the fiber reinforcement and thus of the blade or vane that is fabricated therefrom.

"According to another particular feature of the method, the fiber blank is woven with second and third continuous sets of yarn layers and the shaping of the fiber blank includes eliminating portions of the second and third sets of yarn layers that lie outside the or each second fiber blank portion and the or each third fiber blank portion by cutting them off.

"Yarns of the second and third sets of yarn layers may cross through the first set of yarn layers in the same direction. Alternatively, yarns of the second and third sets of yarn layers cross through the first set of yarn layers in opposite directions.

"In a particular embodiment, the blade or vane airfoil has a profile of varying thickness and the first portion of the fiber reinforcement corresponding to the first portion of the blade or vane has, in the longitudinal direction of the blade or vane, a constant number of layers of yarns. The yarns of the first set of yarns may then be of varying weight and/or thread count.

"Advantageously, three-dimensional weaving is used to make a strip comprising a succession of fiber blanks. They may then be cut out from the strip. The blanks may be woven with their longitudinal direction that corresponds to the direction of the blades or vanes that are to be fabricated extending either in the weft direction or in the warp direction.

"The invention also provides a method for fabricating a turbine engine blade out of composite material comprising fiber reinforcement densified by a matrix, the method comprising: performing three-dimensional weaving to make a single-piece fiber blank; shaping the fiber blank to obtain a single-piece fiber preform having a first portion forming a preform for a blade root and an airfoil, at least one second portion forming a preform for a blade inner platform or for wipers of a blade outer platform, and at least one third portion forming a preform for a blade inner platform reinforcement or for overhangs of a blade outer platform; and densifying the fiber preform with a matrix in order to obtain a composite material blade having fiber reinforcement constituted by the preform and densified by the matrix, and forming a single piece with an inner and/or outer platform(s) incorporated therein.

"Compared with the method described in patent application FR 2 939 129 and in patent application FR 2 939 130 in its application to fabricating a blade, the invention applies in particular to making use of a third portion while shaping the fiber blank, which third portion forms a preform for reinforcement of a blade inner platform or for overhangs of a blade outer platform. As a result, the blade obtained by the method of the invention may present the required properties, i.e. a sealing function and an aerodynamic function at its outer platform and an inner platform having twice the thickness, thereby reinforcing its mechanical strength.

"Furthermore, when the third portion of the fiber preform is used to form a preform for an overhang of a blade outer platform, the blade obtained by the method of the invention enables the flowpath for the gas stream passing through the turbine in which the blade is installed to be reconstituted in part both on the inside (by the blade inner platform) and on the outside (by the overhangs of the blade outer platform).

"Advantageously, in the longitudinal direction corresponding to the longitudinal direction of the fiber blank that is to be fabricated, the fiber blank comprises:

"a first set of a plurality of yarn layers that are linked together to form a first portion of the blank corresponding to the preform for the blade root and airfoil; a second set of a plurality of yarn layers that are linked together at least locally to form at least a second portion of the blank corresponding to the preform for the blade inner platform or for the wipers of the blade outer platform; and a third set of a plurality of yarn layers that are linked together at least locally to form at least a third portion of the blank corresponding to the preform for the reinforcement of the blade inner platform or for the overhangs of the blade outer platform;

"the yarns of the first set of yarn layers being not linked with the yarns of the second and third sets of yarn layers; and

"yarns of the second and third sets of yarn layers crossing through the first set of yarn layers at the level of the or each second portion of the fiber blank and at the level of the or each third portion of the fiber blank, respectively.

"The invention also provides a method for fabricating a turbine engine vane out of composite material comprising fiber reinforcement densified by a matrix, the method comprising: performing three-dimensional weaving to make a single-piece fiber blank; shaping the fiber blank to obtain a single-piece fiber preform having a first portion forming a preform for a vane airfoil, at least one second portion forming a preform for hooks or overhangs of a vane inner platform on the inside of the vane inner platform or forming a preform for hooking legs of a vane outer platform on the outside of the vane outer platform, and third portions forming a preform for a vane inner platform portion forming a flowpath delimiting inner platform portion and forming a preform for a vane outer platform portion forming a flowpath delimiting outer platform portion; and densifying the fiber preform with a matrix in order to obtain a composite material vane having fiber reinforcement constituted by the preform and densified by the matrix, and forming a single piece with inner and outer platforms incorporated therein.

"Advantageously, in the longitudinal direction corresponding to the longitudinal direction of the fiber blank that is to be fabricated, the fiber blank comprises:

"a first set of a plurality of yarn layers that are linked together to form a first portion of the blank corresponding to the preform for the vane airfoil; a second set of a plurality of yarn layers that are linked together at least locally to form at least a second portion of the blank corresponding to the preform for the hooks or overhangs of the vane inner platform or for the hooking legs of the vane outer platform, and a third set of a plurality of yarn layers that are linked together at least locally to form third portions of the blank corresponding to the preforms for the blade inner platform portion and for the blade outer platform portion;

"the yarns of the first set of yarn layers being not linked with the yarns of the second and third sets of yarn layers; and

"yarns of the second and third sets of yarn layers crossing through the first set of yarn layers at the level of the or each second portion of the fiber blank and at the level of each third portion of the fiber blank, respectively.

"The invention also provides a method for fabricating a turbine nozzle segment or compressor stator segment out of a composite material comprising fiber reinforcement densified by a matrix for a turbine engine, the method comprising: making a plurality of turbine nozzle vanes or compressor stator vanes each including an inner platform, an outer platform and an airfoil extending between the inner and outer platforms and forming one piece therewith, the making of each vane comprising: performing three-dimensional weaving to make a single-piece fiber blank; shaping the fiber blank to obtain a single-piece fiber preform having a first portion forming a preform for a vane airfoil, at least one second portion forming a preform for hooks or overhangs of the vane inner platform on the inside of the vane inner platform or forming a preform for hooking legs of the vane outer platform on the outside of the vane outer platform, and third portions forming a preform for a vane inner platform portion forming a flowpath delimiting inner platform portion and forming a preform for a vane outer platform portion forming a flowpath delimiting outer platform portion; and densifying the fiber preform with a matrix in order to obtain a composite material vane having fiber reinforcement constituted by the preform and densified by the matrix, and forming a single piece with inner and outer platforms incorporated therein; and assembling and connecting together a plurality of vanes to form a multi-vane turbine nozzle segment or compressor stator segment out of a composite material, the vanes being connected together by a process including a step selected from a brazing step and a step of connection by co-densification by a matrix of a plurality of vanes assembled together at an intermediary stage of densification.

"The making of each vane may comprise a step of partial densification of the preform by a matrix and a subsequent machining step, and the connection of a plurality of vanes together comprises then assembling machined vanes together and co-densification by a matrix of the assembled machined vanes.

"When the turbine nozzle segment or compressor stator segment is made out of a ceramic matrix composite material, the assembling of the machined vanes together may comprise a pre-ceramic bonding step.

"Still when the turbine nozzle segment or compressor stator segment is made out of a ceramic matrix composite material, the making of each vane may comprise a first and a second step of densification by a ceramic matrix separated by a machining step, and the connection of a plurality of vanes together comprises a step of brazing together vanes assembled together after the second densification step.

"Advantageously, in the longitudinal direction corresponding to the longitudinal direction of the fiber blank that is to be fabricated, the fiber blank comprises:

"a first set of a plurality of yarn layers that are linked together to form a first portion of the blank corresponding to the preform for the vane airfoil; a second set of a plurality of yarn layers that are linked together at least locally to form at least a second portion of the blank corresponding to the preform for the hooks or overhangs of the vane inner platform or for the hooking legs of the vane outer platform, and a third set of a plurality of yarn layers that are linked together at least locally to form third portions of the blank corresponding to the preforms for the vane inner platform portion and for the vane outer platform portion;

"the yarns of the first set of yarn layers being not linked with the yarns of the second and third sets of yarn layers; and

"yarns of the second and third sets of yarn layers crossing through the first set of yarn layers at the level of the or each second portion of the fiber blank and at the level of each third portion of the fiber blank, respectively.

"The present invention also provides a turbine engine blade or vane made of composite material comprising fiber reinforcement obtained by three-dimensional weaving of yarns and densified by means of a matrix, the blade or vane comprising a first portion constituting at least an airfoil of the blade or vane and that is formed integrally with:

"at least one second portion constituting an inner part of a blade or vane inner platform or an outer part of a blade or vane outer platform; and

"at least one third portion constituting an outer part of a blade or vane inner platform or an inner part of a blade or vane outer platform;

"first, second and third portions of the fiber reinforcement corresponding to the first, second, and third portions of the blade or vane being mutually interleaved at least in part with the yarns of the first portion of fiber reinforcement penetrating into the second portion of fiber reinforcement and into the third portion of the fiber reinforcement.

"The blade or vane may be made of ceramic matrix composite material.

"According to a particular feature of the blade or vane, yarns of the second portion and of the third portion of the fiber reinforcement cross through the first portion of the fiber reinforcement.

"The blade or vane airfoil may have a profile of varying thickness and the first portion of the fiber reinforcement corresponding to the first portion of the blade or vane may have, in the longitudinal direction of the blade or vane, a constant number of layers of yarns that are of varying weight and/or varying thread count.

"In a particular embodiment, the invention provides a turbine engine blade made of composite material comprising fiber reinforcement obtained by three-dimensional weaving of yarns and densified by means of a matrix, the blade comprising a first portion constituting an airfoil and root of the blade and that is formed integrally with:

"at least one second portion constituting a blade inner platform or wipers of a blade outer platform; and

"at least one third portion constituting an inner platform reinforcement or overhangs of a blade outer platform;

"first, second and third portions of the fiber reinforcement corresponding to the first, second, and third blade portions being mutually interleaved at least in part, with the yarns of the first portion of fiber reinforcement penetrating into the second portion of fiber reinforcement and into the third portion of the fiber reinforcement.

"According to a particular feature of the blade, yarns of the second portion and of the third portion of the fiber reinforcement cross through the first portion of the fiber reinforcement.

"In a particular embodiment, the invention provides a turbine engine vane made of composite material comprising fiber reinforcement obtained by three-dimensional weaving of yarns and densified by means of a matrix, the vane comprising a first portion constituting an airfoil of the vane and that is formed integrally with:

"at least one second portion constituting hooks or overhangs on the inside of a vane inner platform or hooking legs on the outside of a vane outer platform; and

"at least one third portion constituting a flowpath delimiting inner platform portion or a flowpath delimiting outer platform portion;

"first, second and third portions of the fiber reinforcement corresponding to the first, second, and third portions of the vane being mutually interleaved at least in part with the yarns of the first portion of fiber reinforcement penetrating into the second portion of fiber reinforcement and into the third portion of the fiber reinforcement.

"According to a particular feature of the vane, yarns of the second portion and of the third portion of the fiber reinforcement cross through the first portion of the fiber reinforcement.

"The invention also provides a turbine nozzle segment or a compressor stator segment comprising a plurality of vanes as defined above which are connected together.

"The invention also provides a turbine engine fitted with at least one blade or vane as defined above.

BRIEF DESCRIPTION OF THE DRAWINGS

"Other characteristics and advantages of the present invention appear from the following description made with reference to the accompanying drawings, which show implementations having no limiting character. In the figures:

"FIG. 1 is a perspective view of a turbine engine blade having inner and outer platforms incorporated therein;

"FIG. 2 is a highly diagrammatic view of an example arrangement of three sets of layers of yarns in a three-dimensional woven fiber blank for use in making a fiber preform for a blade of the kind shown in FIG. 1;

"FIGS. 3, 4, and 5 show successive steps in the making of a fiber preform for a blade as shown in FIG. 1, starting from the fiber blank of FIG. 2;

"FIGS. 6A and 6B are highly diagrammatic views of another example of an arrangement of three sets of layers of yarns in a three-dimensional woven fiber blank for making a fiber preform for a blade of the kind shown in FIG. 1;

"FIG. 7 is a section view showing the profile laid out flat of an airfoil of a blade such as that shown in FIG. 1;

"FIG. 8 is a section view of a set of warp yarn layers suitable for obtaining a profile of the kind shown in FIG. 7;

"FIGS. 9A and 9B are warp section views showing one way of weaving the FIG. 2 fiber blank;

"FIG. 10 is a fragmentary section view on a plane parallel to the warp and weft directions in a portion of the FIG. 2 fiber blank corresponding to the location of the junction between the airfoil and the inner platform of the blade;

"FIG. 11 is a fragmentary weft section view in a portion of the FIG. 2 fiber blank corresponding to the location of the junction between the airfoil and the outer platform of the blade;

"FIG. 12A is a weft section view showing an example of the arrangement of weft yarns in a fiber blank portion corresponding to a portion of the blade root;

"FIGS. 12B to 12D are weft section views showing warp planes for an example of (multilayer) three-dimensional weaving in the fiber blank portion of FIG. 12A;

"FIG. 13 is a fragmentary diagrammatic section view showing another way of making a blank portion corresponding to a blade root;

"FIGS. 14 and 15 are highly diagrammatic views of two embodiments of a woven fiber strip obtained by three-dimensional weaving and comprising a plurality of fiber blanks such as that of FIG. 2;

"FIG. 16 shows successive steps of a method of fabricating a turbine engine blade in accordance with the invention; and

"FIG. 17 shows successive steps of a method of fabricating a turbine engine blade in accordance with the invention.

"FIG. 18 is a perspective view of a turbomachine vane with incorporated outer and inner platforms;

"FIG. 19 is a highly diagrammatic representation of the disposition of two sets of layers of yarns in a three-dimensional woven fiber blank for use in making a fiber preform for a vane as shown in FIG. 18;

"FIGS. 20, 21 and 22 show successive steps in making a fiber preform for a vane as shown in FIG. 18, starting from the fiber blank of FIG. 19;

"FIG. 23 shows successive steps in an implementation of a method of making a turbine nozzle segment in accordance with the invention;

"FIG. 24 is a perspective view of a turbine nozzle segment obtained by connecting together a plurality of vanes such as shown by FIG. 18;

"FIG. 25 shows successive steps in another implementation of a method of making a turbine nozzle segment in accordance with the invention;

"FIG. 26 is a very diagrammatic and partial half axial section view of a low-pressure turbine of a turbine engine comprising a turbine nozzle in CMC material; and

"FIG. 27 is a very diagrammatic and partial half axial section view of a compressor of a turbine engine comprising a compressor stator in CMC material."

For additional information on this patent application, see: NUNEZ, ROMAIN; Blanchard, Stephane; Renon, Guillaume; Coupe, Dominique; Roussille, Clement; Beaujard, Antoine Jean-Philippe; Fremont, Elric Georges Andre. Turbine Engine Blade Or Vane Made of Composite Material, Turbine Nozzle Or Compressor Stator Incorporating Such Vanes and Method of Fabricating Same. Filed September 7, 2012 and posted February 6, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=3312&p=67&f=G&l=50&d=PG01&S1=20140130.PD.&OS=PD/20140130&RS=PD/20140130

Keywords for this news article include: Herakles, Nanotechnology, Emerging Technologies, Ceramic Matrix Composites.

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Source: Politics & Government Week


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