JP2007064220A - Assembly and method for mounting root part of blade of turbine, blower, and compressor, and turbine having the assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of mounting a fixed or a movable metal turbine blade at the opening of a metal support part to improve the durabilities of both components against contact pressure and extremely easily and rapidly perform the measure also when the mounting part of the root part of the blade is repaired in the same manner as in the case where the turbine blade is first installed. <P>SOLUTION: This assembly is formed of a metal and used for mounting the root part 121 of the fixed or movable blades of a turbo machine to the opening 101 of the metal support part such as a casing, a fixed flange, or a rotor disk 10. The assembly is coated or impregnated with an adhesive agent between the root part 121 and the opening 101. Specifically, the assembly is formed of a fabric of lath yarn and/or polyamide yarn, or advantageously a non-metallic film 20 of polytetrafluoroethylene. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for attaching a fixed or movable metal turbine blade root to an opening in a metal support and an assembly for such attachment.

  Conventionally, the surface of the base of a metal blade, in particular a titanium blower, is treated. The contact between the load surface of the blade root and the slope of the opening (or slot) of the fan disk that houses these roots is actually subjected to multiple forces, and these forces cause these Parts can be damaged and the components in contact can even break prematurely.

  The present invention is not limited to situations where the blade root support is provided with a fan rotor disk, but is attached to other situations where a movable blade is mounted, for example, to the rotor disk of a low pressure compressor or within the intake area of a high pressure compressor. Including the situation equally.

  The present invention also relates to a situation in which the support portion is a casing or a flange that supports the fixed blade.

  Various types of stress are experienced in the contact area between the root of the blade and the opening that accommodates the root.

  In particular, a phenomenon called “fretting”, that is, contact wear, which is the result of one component repeatedly rubbing against another component, and the fatigue process is different, resulting in material damage due to the resulting frictional force. This phenomenon is particularly observed when there is contact between two titanium components.

  Therefore, as well as wearing the load surface at the base of the blade, these areas, which are the areas in contact with the walls of the opening, tend to damage the material, and even these areas of deformation are even deformed. To do.

  In addition to this, the degree of local stress is very high due to the coefficient of friction at the interface between the walls where the base of the blade contacts the opening caused by contacting the metal with the metal.

  In order to solve these problems, in particular, attempts have been made to increase the wear resistance of the contact surface and reduce the friction coefficient.

  In order to achieve this purpose, a surface coating is generally applied to the root of the blade as a metallic alloy that is resistant to fretting, in particular by plasma projection, or it is itself coated and coated on the blade. It is possible to use protective elements formed from one or more metal foils (or tinsel) that can surround the root and these protective elements can be combined with a lubricious varnish. is there.

  With this kind of solution, the coefficient of friction can usually be reduced to a value above 0.2. However, during operation this number increases regularly to about 0.5, or even exceeds when the wear is over.

  For example, US Pat. No. 5,160,243 proposes to take a means of placing a metal foil between a blade and a disk, both made of titanium.

Such treatment can improve the fretting and wear properties. On the other hand, even when repairing locally in the same way as during the initial installation, it takes a relatively long time to implement these solutions. In any case, it is actually necessary to treat the entire load surface of the support at the base of the blade, which makes the operation longer and expensive. In addition, long and complex and relatively aggressive treatments (using acid and / or mechanical strippers) that can remove the material that makes up the surface of the substrate, if a coating change is required And the substrate may be damaged, especially due to surface and / or dimension changes.
US Pat. No. 5,160,243

  One object of the present invention is to attach a fixed or movable turbine blade to the opening of a metal support to improve both resistance to contact pressure between these components. At the same time, when repairing the base of the blade as well as during the initial installation, it is also possible to provide another way in which this procedure can be carried out very simply and quickly.

According to the invention, this object is achieved by a method of mounting the base of a fixed or movable turbine blade, which is made of metal, characterized in that it comprises the following steps: That is,
a) a non-metallic film made of polyamide and coated or impregnated with a polymer adhesive is placed between the root and the opening;
b) the step in which the adhesive is to be applied in such a way that the film adheres to the base of the blade and / or the surface of the opening;
It is.

  In this case, the film is understood to replace the wear-resistant metal coating of the prior art.

  What has actually been identified is selected for its wear-resistant properties and is placed directly between the two metallic components, for example at the base of the blade, and hence the surface of the opening of the support By using such a non-metallic film that comes into contact with the friction coefficient can be reduced in the contact area, thus significantly reducing the mounting wear at the root of the blade Therefore, it is possible to increase the service life of this connection without compromising its mechanical properties before it becomes necessary to rely on repairs.

  This type of film has already been used for the attachment of the base of a blade made of composite material, and a type of film obtained from a resistant textile fabric impregnated with a resin is used.

  However, according to the present invention, this type of solution is currently proposed for the base of metallic blades, in particular made of titanium, with completely satisfactory results.

  Obviously, the use of such a non-metallic film for attachment between the opening and the root of the blade is only possible in the region of the turbine called low temperature.

  In addition to this, it is appropriate to note that the installation of such a film is clearly simpler than the deposition of metal coatings, for example performed by plasma deposition techniques.

  Moreover, if repair of the wear surface at the base of the blade is required, all or part of the film is removed by peeling directly with a scalpel in an essentially simple manner. Using and fixing the new exchange membrane itself is also much easier and faster than coating metal without the need for technically complex equipment and without the risk of damaging the support. Is called.

  Thus, the method according to the invention can be used during such an initial installation when such an installation is first performed according to the present invention or when relying on a wear-resistant metal coating. As well as repairing the attachment between the root of the blade and its opening.

  Advantageously, the film is pre-loaded with a binder on the surface or over the entire material.

  Preferably, the binder is heat-polymerizable, and in step b), the assembly comprising at least the blade root, the support and the film is brought to a temperature at which the binder can function. For a predetermined minimum time.

  According to another embodiment of the method according to the invention, at the stage of step a), the root of the blade is covered with a metal foil, and then the above abrasion-resistant film is placed between the thin film and the opening. .

  The present invention also relates to an assembly for attaching a metal, fixed or movable turbine blade root to an opening in a metal support, the assembly being reliable, concise, and in place. It is economical to place and repair.

  This object is achieved by the fact that the assembly comprises at least one non-metallic film comprising a polyamide coated or impregnated with a polymer binder between the root and the opening.

  According to a preferred embodiment, the film is arranged so that the binder adheres to the root of the blade. Or a film may adhere to the surface of the opening part of a support part.

  According to a preferred embodiment, the film comprises glass fibers, polytetrafluoroethylene, in particular Teflon®, and / or polyamides, especially as fibers, in particular Kevlar or Nomex (both registered trademarks).

  Among the various possible solutions to the structure of the polymer film, the nonmetallic film advantageously comprises a material made of synthetic fibers. In fact, there are many types of synthetic fibers that exhibit a low coefficient of friction as well as high wear resistance.

  Advantageously, the binder is thermopolymerizable, so that the moment at which the binder functions can be monitored by placing the assembly in an autoclave where the minimum temperature is reached at a given time. By way of example and not limitation, the binder is resin-based and consists of a phenol or polyurethane resin.

  The assembly according to the invention further comprises a situation in which the root of the blade is received directly in the opening, the assembly further comprising at least one metal foil attached to the root of the blade, the non-metallic film described above being Including situations between the membrane and the opening.

  The root of the blade is preferably made of titanium, aluminum or steel or one of their alloys.

  The blade support is preferably made of titanium, aluminum, steel, or one of their alloys.

  The invention also relates to a turbine blower comprising an assembly for attachment of the root of the blade according to one of the definitions made so far, wherein the blade is movable and the support is formed by a rotor disk. Features.

  The present invention also relates to a turbine compressor comprising an assembly for attachment of a blade root according to one of the definitions made so far, wherein the blade is movable and the support is formed by a rotor disk. Features.

  The invention also relates to a turbine compressor comprising an assembly for attachment of a blade root according to one of the definitions made so far, characterized in that the blade is movable and the support is formed by a flange. To do.

  Such a compressor is in particular a low-pressure type turbine compressor, but the present invention also provides that the temperature reached can be any component of the wear-resistant layer, ie the mechanical properties of the film and the binder. It may be related to a blade located at the intake of the high-pressure compressor to such an extent that does not impair it.

  Finally, the invention also relates to a turbine comprising an assembly for the attachment of the root of the blade according to one of the definitions made so far.

  The invention will be readily understood and its advantages will become more apparent from the following detailed description of embodiments of the invention disclosed without limitation to the following examples.

  This will be described with reference to the accompanying drawings.

  FIG. 1 shows a mounting on the rotor of a blower disk 10 or blade 12, with its root 121 located in one of a plurality of openings 101 in the disk 10.

  More precisely, each opening 101 has a shape substantially complementary to the shape of the root 121 of the blade 12 and forms a dovetail mounting portion.

  The openings 101 are distributed equidistantly in the radial direction over the entire length of the peripheral edge of the disk 10 and open toward the outside.

  As can be seen, the figure shows a cross section of the disk 10, i.e. an enlarged portion of a section perpendicular to the rotational axis of the fan, and each root 121 of the blade 12 is a symmetrical profile with two side walls 122. In the direction of the free end of the root portion 121 of the blade 12, from the main body of the blade 12 to the rotation axis and the peripheral portion of the disk 10, and orthogonal to the perpendicular direction of the corresponding blade 12 mainly Branch to each other up to the bottom wall 124.

  The opening 101 has a shape similar to that of the side wall 102, and is inclined outward from the peripheral edge to the bottom wall 104 in the direction of the inner portion of the disk 10.

  The dimensions of the root portion 121 and the blade 101 of the blade 12 are such dimensions that the root portion 121 is held by the opening 101 when the rotor 10 is stationary, so that the bottom wall 124 of the root portion 121 is the opening 101. It is possible to contact the bottom wall 104.

  When the rotor 10 is operable while the engine or turbine is being machined, the rotor 10 rotates about the central axis so that the blades 12 are brought radially outward by centrifugal force, that is, in the direction of the arrow 13 in FIG. It will move. At this moment, the side wall portion 122 of the root portion 121 of the blade 12 is supported by the side wall portion 102 of the opening portion 101, whereby the blade 12 can be held inside the opening portion 101, that is, connected to the disk 10. It will definitely be possible.

  No matter how the rotational speed of the rotor 10 changes, the sliding pressure of the base 121 of the blade is associated with the contact pressure of the base 121 and the coefficient of friction between the material of the blade 12 and the material of the disk 10. A shear force is simultaneously generated on the blade 10 and the blade 12, with one moving radially from one millimeter to several millimeters relative to the other.

  In particular, as can be seen from FIG. 1, during operation, the contact area indicated by reference numeral 14, called the load surface, which receives a substantial force is the side wall 122 of the root 121 and the side wall 102 of the opening 101. There is a non-contact region which is indicated by reference numeral 16 and which is not subjected to any mechanical contact stress during rotation of the rotor formed from the disk 10.

  According to the present invention, because of the relative movement between the root portion 121 of the blade 12 and the opening portion 101 of the rotor 10, deterioration caused by fatigue and wear of the contact surfaces of the side wall portions 102 and 122 is caused by the outside of the root portion 121. This is reduced by using a non-metallic film 20 that covers the entire surface.

  More precisely, advantageously glass and / or aramid fibers, such as those known from Saint-Gobain's CHEMFAB fabric, Nomex® or Kevlar® A film 20 made from an abrasion-resistant fabric is used.

  The film 20 is attached to the outer surface of the root 121 by a binder that coats or impregnates the film 20 on at least the surface of the film 20 prior to attachment, which binder is preferably of the resin type, Preference is given to phenolic resins or urethane resins.

  For example, Pont de Nemours Vespel (registered trademark) for titanium alloy blade 12 and titanium alloy disk 10 using a phenolic resin called Plyophene 23057 from Durez as a binder. ) Abrasion-resistant fabric called ASB0664 (film made of Nomex® and Teflon® (fabric made of Teflon® fibers) with phenolic resin binder) The use of 20 works.

  This film 20 has a first surface coated with a layer of polytetrafluoroethylene as a lubricant and a second surface intended to be adhesively bonded with good adhesion and holding surface. This film is about a few tenths of a millimeter thick.

  Adhesive is applied to the second surface of the film in a regular manner, and then this second surface of the film 20 pre-treated with adhesive is applied to the side wall 122 and bottom of the root 121 of each blade 12. Located on the wall 124.

  The assembly formed by the root portion of the blade 121, the resin, and the film 20 are preferably placed under pressure during bonding to polymerize the resin. The pressure used is 7 to 14 MPa. This ensures that the solvent is discharged as well as the adhesive adheres well across the surface.

  During this time, polymerization is performed, and in this embodiment, the polymerization is performed at 170 ° C. for 1 hour.

  As shown in FIG. 1, a crushed film 20 is obtained that adheres completely across the surface of the root 121 of the blade 12 in a manner that is reliably present in the region 14 after attachment.

  Advantageously, in the embodiment shown, the film 20 comprises a layer of polytetrafluoroethylene (PTFE) on the surface opposite the surface that will adhere to the root 121, which layer is of a very effective extent. A lubricating surface is formed that reduces the coefficient of friction associated with the surface of the side wall 102 of the opening 101, and this coefficient of friction can be reduced to 0.1.

  After adhesive bonding, the blade root 121 can be cleaned to remove excess resin by blasting with a glass bead.

  Advantageously, by providing the above-described embodiment according to the attachment of FIG. 1, after the tests performed on the attachment, the useful life of the attachment between the root 121 and the opening 101 is increased. It has been proven that it can be increased to a considerable extent.

  Actually, as a result of these abrasion tests, the durability increased from 10,000 cycles by coating the metal as in the conventional case to 800,000 cycles by the film 20 of the embodiment without being damaged.

  Therefore, it will be appreciated that, in addition to the advantages associated with ease of installation and modification, the use of a non-metallic, abrasion resistant film 20 comprising a layer of polytetrafluoroethylene in accordance with the present invention provides friction. The resistance to wear caused by is significantly increased.

  Among other advantages of the present invention, it should be noted that, for example, metal coatings, particularly plasma deposition, or structural changes in the material of the disk 10 that sometimes occur in the form of sweating while removing this coating. It can be prevented.

  In addition to this, non-destructive inspection of the blade root 121 is made easier by using a non-metallic film 20 to protect against wear. For example, it is possible to rely on eddy current technology, whereby small size (from about 0.1 mm) defects (especially microcracks or cracks) can be detected.

  Apart from this, a machine called “undercut”, which consists of an improvement in this way, which consists in widening the opening in the region where the load surface 14 where the stress concentration occurs, generally close to the non-contact region 16. It becomes possible to eliminate the processing procedure.

  Thus, by using an industrial fabric comprising reinforcing fibers (of aramid type) and Teflon treated fibers in order for the film 20 to obtain a lubrication effect, the coefficient of friction in the region 14 is reduced and thus Although the force generated is reduced, this improves the mechanical resistance.

  Advantageously, the film 20 is an industrial fabric formed from glass fibers and / or polyamide fiber materials, preferably comprising polytetrafluoroethylene.

  By devising as described above, the film 20 can be applied over the entire surface of the root portion 121 of each blade. This solution is simpler and quicker, but in practice it is sufficient for the film 20 to cover the side wall 122 of the root 121 in the contact area, i.e. the load surface 14, in order to achieve the object of the invention. It will be understood.

  According to another example, this technique can also be applied by adhesively bonding the non-metallic film 20 to the wall (not shown) of the opening 101.

  According to another embodiment not shown, the film 20 can be applied simultaneously to the root 121 of the blade 12 and the wall of the blade 101.

  The method according to the invention can easily be used during the initial installation, but even if it is initially installed in this way according to the present invention, even if it has previously relied on a metal wear-resistant coating. Note that it can equally easily be used to repair the attachment between the root 121 of the blade 12 and its opening 101.

  When relying on metallic wear-resistant coatings in advance, after pre-treatment consisting of blasting and cleaning the above coating, or after completely removing this old metal coating, repair the old metal coating. The film 20 can be applied.

  Also, as shown in FIG. 2, according to another embodiment, the polymer film 20 is adhesively bonded to a metal foil 22 made of, for example, a nickel-based superalloy or stainless steel.

  In this figure, elements that are the same as in FIG. 1 remain the same.

  In this case, in order to carry out the present invention, a rigid core arranged inside the foil 22 is used in order to avoid deformations that can occur during the polymerization of the adhesive under pressure.

  The foil 22 is a cambered sheet having a U-shaped cross section, and its arms are divided into two parts so as to form an obtuse angle opposite the inside of the U-shape. This shape approaches the shape of the root portion 121 of the blade 121 so that the end section of the U-shaped arm of the foil covers the contact area 14 between the root portion 121 and the opening 101.

  In FIG. 2, the film 20 covers the entire outer surface of the foil 22.

  Even in this case, according to another example, the film 20 may cover the entire surface of the wall of the opening 101, or the entire outer surface of the foil 22 and the entire surface of the wall of the opening 101 simultaneously, or at least one of these surfaces. It is possible to cover only the region comprising the other or both regions 14.

  This example embodiment is very close to the embodiment described above with respect to FIG. 1, the only difference being the presence of the foil 22. Again, according to the present invention, both the new foil 22 without a coating and the foil 22 that has been used and provided with a coating (regardless of whether this conventional metallization is removed), the film It is understood that the film 20 can be installed to repair part or all of the surface of a foil previously coated with such a film 20 as well as the 20 can be installed. .

  Therefore, the present invention is very easy and, according to some other examples that give great flexibility to the application, whether during the initial installation or to repair an existing installation, It will be appreciated that very good wear resistance results can be obtained without changing the function of the attachment of the blade according to the prior art.

Fig. 4 shows a partial cross-sectional view of the fan, showing the attachment at the root of the blade in the rotor, where the blade is subjected to rotational centrifugal force. FIG. 2 shows a view similar to FIG. 1 according to another embodiment of the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Disc, rotor 12 Blade 13 Blade moving direction 14 Contact area 16 Non-contact area 20 Film 22 Metal foil 101 Opening 102, 122 Side wall 104, 124 Bottom wall 121 Root

Claims (17)

  An assembly for attaching a base (121) of a metal, fixed or movable turbomachine blade (12) to an opening (101) of a metal support, the assembly comprising: Assembly comprising at least one non-metallic film (20) made of polyamide and coated or impregnated with a polymer adhesive between the part (121) and the opening (101) .   2. Assembly according to claim 1, characterized in that the film (20) consists of glass fibers and / or polytetrafluoroethylene.   Assembly according to claim 1 or 2, characterized in that the film (20) consists of a fabric made of synthetic fibres.   4. Assembly according to any one of claims 1 to 3, characterized in that the adhesive is thermopolymerizable.   The assembly according to claim 4, characterized in that the adhesive comprises a phenolic resin or a urethane resin.   The assembly further comprises at least one metal foil (22) attached to the root of the blade, wherein the non-metallic film (20) is disposed between the foil (22) and the opening (101). 6. Assembly according to any one of the preceding claims, characterized in that   The root (121) of the blade (12) is made of titanium, aluminum or steel or one of their alloys, according to any one of claims 1 to 6 The assembly described.   The root (121) of the blade (12) according to any one of claims 1 to 7, characterized in that the blade (12) is movable and the support is formed by a disk (10) of the rotor. Turbomachine fan with assembly for mounting).   8. Assembly for mounting a blade root according to any one of claims 1 to 7, characterized in that the blade (12) is movable and the support is formed by a disk (10) of the rotor. A turbomachine compressor.   8. A turbomachine compressor comprising an assembly for mounting a blade root as claimed in any one of the preceding claims, characterized in that the blade is fixed and the support is formed by a flange.   A turbomachine comprising an assembly for mounting the root of the blade according to any one of claims 1-7. A method for attaching a base of a fixed, movable turbine blade (12) made of metal to an opening (101) of a metal support (10), the method comprising:
a) a non-metallic film (20) comprising polyamide and coated or impregnated with a polymer adhesive is placed between the root (121) and the opening (101);
b) an adhesive to be applied so that the film (20) adheres to the surface of the root (121) and / or the opening (101) of the blade (12);
A method comprising:   That the adhesive is heat-polymerizable and that the assembly comprises at least the blade root (121), the support (10) and the film (20) during the stage of step b). The mounting method according to claim 12, wherein the mounting method is arranged in an autoclave that has reached a temperature that can be adjusted.   14. A mounting method according to claim 12 or 13, characterized in that the film (20) is arranged such that the adhesive adheres to the root (121) of the blade.   14. The blade root is covered with a metal foil (22) during step a) and the film is placed between the foil (22) and the opening (121). Installation method described in 1.   16. A mounting method according to any one of claims 12 to 15, characterized in that the film (20) consists of glass fibers and / or polytetrafluoroethylene.   16. A method according to any one of claims 12 to 15, characterized in that the film (20) consists of a fabric made of synthetic fibres.

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