EP3740658A1

EP3740658A1 - Turbomachine ring

Info

Publication number: EP3740658A1
Application number: EP19703160.2A
Authority: EP
Inventors: Quentin Pierre Hubert BOMBERAULT; Martin JUBIEN; Julien Michel Auguste ROBERT
Original assignee: Safran Aircraft Engines SAS
Current assignee: Safran Aircraft Engines SAS
Priority date: 2018-01-16
Filing date: 2019-01-09
Publication date: 2020-11-25
Anticipated expiration: 2039-01-09
Also published as: CN111615585B; EP3740658B1; CN111615585A; FR3076852A1; FR3076852B1; US11566540B2; US20200392871A1; WO2019141918A1

Abstract

Turbomachine ring and a turbomachine comprising such a ring and a method for repairing such a ring, the turbomachine ring comprising an essentially cylindrical support (31v) comprising a front surface (36) in which a notch (35) is made, one or more sectors (32) forming a crown configured to create an air stream section, each sector (32) comprising a hook portion (34) projecting in the direction of the support (31v) and engaging in the notch (35) of the support (31v), and an anti-wear device (40) having a U-shaped portion (41), provided in the notch (35) of the support (31v) and pressed at least against the radially external surface (35d) of the notch (35), and a tab portion (42) continuously extending the U-shaped portion (41), pressed against and affixed to the front surface (36) of the support (31v).

Description

TURBOMACHINE RING

FIELD OF THE INVENTION

The present disclosure relates to a turbomachine ring and a turbomachine comprising such a ring and a method of repairing such a ring. It may especially be a compressor ring or turbine of an aircraft engine, single or dual flow.

STATE OF THE PRIOR ART

In many turbomachine compressors, but also in some turbines, the vanes are mounted on sectors forming a crown materializing the air stream: these sectors are then mounted on the stator housing using parts hook engaging in notches of a stator support.

However, during operation of the turbomachine, due in particular to the vibrations experienced by the sectors of the ring, the hooks of the sectors rub and wear the notches of the support: there is thus sometimes an erosion on the inner faces of the notches . Naturally, such erosion modifies the chains of ribs between the parts of the ring, in particular opening games and moving parts, which can lead to leaks and cause performance losses.

Therefore, it is desired to repair these notches without replacing the entire support.

A possible repair option would be to locally recharge the material of the notch, either by thermal spraying, or by welding or brazing. However, such solutions are difficult to achieve because of the difficulty of access to the area to be reworked and the geometry of the area to be recharged.

Another option would be to fix a fret type element on each side of the notch to repair. However, it is difficult to reshape the complete vein. Indeed, a resinization causes too large dimensional dispersions; moreover, the temperature resistance of the resins is not sufficient in the context of a turbomachine application. There is therefore a real need for a turbomachine ring, and a turbomachine comprising such a ring and a method of repairing such a ring, which are devoid, at least in part, of the drawbacks inherent in the known methods. above.

PRESENTATION OF THE INVENTION

The present disclosure relates to a turbomachine ring, comprising a support, substantially cylindrical, having a front surface in which is formed a notch, one or more sectors forming a ring configured to materialize a section of air stream, each sector. comprising a hook portion projecting towards the support and engaging in the notch of the support, and an anti-wear device having a U-shaped portion provided in the notch of the support and pressed at least against the radially outer surface of the notch, and a tongue portion, continuously extending the U-shaped portion, plated and fixed against the front surface of the support.

With such an anti-wear device, it is possible to easily and effectively repair a worn support notch. It is also possible to set up such an anti-wear device from the beginning to facilitate the maintenance of the turbomachine. Indeed, thanks to such an anti-wear device, in case of friction or vibration between the sector and the support, the notch of the support is protected, only the anti-wear device being used if necessary. However, the anti-wear device can be easily replaced, which drastically reduces the time and cost of repair.

In addition, thanks to the tongue portion pressed and fixed against the front surface of the support, it is possible to effectively maintain the anti-wear device in the plated position within the notch while providing increased accessibility allowing a easy attachment and removal of the anti-wear device.

The fixing of the anti-wear device on the support also simplifies the nomenclature parts of the turbomachine and the logistics associated with maintenance: indeed, this avoids assigning an individual reference to the device antiwear.

In some embodiments, the U-shaped portion of the anti-wear device is under elastic stress. This ensures permanent veneering of the U-shaped part against the radially outer surface of the notch.

In some embodiments, the radially inner wall of the U-shaped portion of the anti-wear device forms, at rest, a first angle of between 5 ° and 20 °, preferably between 10 ° and 15 °, with the direction of the radially outer wall of the U-shaped part. In other words, such an angle occurs when the anti-wear device is not inserted into the notch, for example before the repair of the support or after its extraction. Such an angle is measured in an axial plane. It makes it possible to generate the elastic stress mentioned above when the anti-wear device is put in place in the notch.

In some embodiments, the tab portion of the anti-wear device is under elastic stress. This remembers the U-shaped part of the anti-wear device towards the bottom of the notch, thus stabilizing its position.

In some embodiments, the tab portion of the anti-wear device forms, at rest, a second angle of between 5 ° and 20 °, preferably between 10 ° and 15 °, with the direction orthogonal to the wall radially outer portion of the U-shaped portion. In other words, such an angle occurs when the anti-wear device is not inserted into the notch, for example before the repair of the support or after its extraction. Such an angle is measured in an axial plane. It makes it possible to generate the elastic stress mentioned above when the anti-wear device is put in place in the notch.

In some embodiments, the tab portion of the anti-wear device is, at rest, substantially orthogonal to the radially inner wall of the U-shaped portion.

In some embodiments, the tab portion of the anti-wear device continuously extends the U-shaped portion radially inwardly. Thus, the tongue portion is fixed to the radially inner area of the front surface of the support. This facilitates access to the anti-wear device from inside the ring, helps to press the U-shaped part of the anti-wear device against the radially outer surface of the notch, and protects the frontal surface of the support from friction. with the ring area. In some embodiments, a space is left between the U-shaped portion of the anti-wear device and the bottom of the notch of the support. This space is used to slide a tool between the anti-wear device and the bottom of the notch to facilitate the extraction of the anti-wear device.

In some embodiments, a space is left between the U-shaped portion of the anti-wear device and at least a portion of the radially inner surface of the notch of the support. This reinforces the plating of the U-shaped portion of the anti-wear device against the radially outer surface of the notch of the support.

In some embodiments, the tab portion of the anti-wear device is attached to the front surface of the support by attachment points. These attachment points may in particular have a diameter of less than 1 mm, or even 0.5 mm. This facilitates the fixing of the anti-wear device but also its removal, such fixing points being easy to break.

In some embodiments, the attachment points are evenly distributed along the tab portion of the anti-wear device, particularly in the circumferential direction.

In some embodiments, at least an angular distance of 15 °, preferably 20 °, separates two attachment points. Removing the fixing points facilitates the breaking of the attachment points and thus the removal of the anti-wear device.

In some embodiments, the tab portion of the anti-wear device is fixed on the front surface of the support by welding. It may in particular be soldering points by capacitor discharge. The weld indeed withstands the high operating temperatures of the turbomachine and causes only small dimensional dispersions.

In some embodiments, the anti-wear device is separable from the support under the effect of a manual tearing force. This is a light tearing force for an operator, which allows easy and fast maintenance. In particular, it is possible to separate the anti-wear device by simple leverage by inserting a tool, such as a screwdriver tip, between the anti-wear device and the support. In some embodiments, the thickness of the anti-wear device is between 0.1 mm and 1 mm, preferably between 0.2 mm and 0.6 mm. This is compatible with the usual size of the notches of the turbomachine ring supports.

In some embodiments, the thickness of the anti-wear device is scalable. Indeed, it is preferable to reserve a greater thickness in the areas of the notch against which the sector is caused to rub and a lower thickness in the other areas to reduce the probability of unintentional contact with the sector. Thus, in particular, the thickness of the radially inner wall of the U-shaped portion of the anti-wear device may be less than the thickness of the radially outer wall of the U-shaped part.

In some embodiments, the anti-wear device has a hardness less than that of the support. This allows a preferential wear of the anti-wear device relative to the support, thus preserving the support.

In some embodiments, the anti-wear device has a hardness lower than that of the sector hook. This allows a preferential wear of the anti-wear device relative to the hook of the support, thus preserving the hook of the support.

In some embodiments, the anti-wear device is made of Inconel.

In some embodiments, the anti-wear device comprises a base element in the form of a profile, preferably of the foil type. This foil is preferably metallic. This basic element can have any number of characteristics among those mentioned above.

In some embodiments, the anti-wear device further comprises an additional U-shaped member provided within the U-shaped portion of the base member. This additional element may have any number of characteristics among those mentioned above. It is thus possible to separate certain functions from the basic element and the additional element and / or to offer a differentiated behavior with respect to the support on the one hand and the hook of the sector on the other hand. In particular, the basic element can provide the mechanical positioning and fixing functions of the anti-rotation device. while the additional element can provide the preferential wear functions thus protecting the hook of the sector and the notch of the support.

In some embodiments, the additional element takes the form of a profile, preferably of the foil type, preferably metal, distinct from the base element. The additional element can therefore be manufactured independently of the base element and then assembled with the latter.

In some embodiments, the additional element is under elastic stress. This allows the additional element to be pressed against the radially outer surface of the U-shaped part of the base element.

In some embodiments, the additional element takes the form of a coating deposited on the base element. The anti-wear device is thus monobloc.

In some embodiments, the base element and the additional element form two layers of the same profile, preferably of the foil type. The anti-wear device is thus monobloc.

In some embodiments, the thickness of the additional element is between 0.1 and 0.4 mm, preferably between 0.1 and 0.3 mm.

In some embodiments, the additional element has a hardness lower than that of the base element. This allows a preferential wear of the additional element relative to the support, the base element retaining a higher mechanical strength.

In some embodiments, the additional element is made of an alloy based on nickel and / or cobalt. It may be provided with an anti-wear coating, for example a deposit based on nickel and / or chromium.

In some embodiments, the anti-wear device is sectorized. Each sector can in particular extend over an angular sector between 30 and 60 °.

In some embodiments, the sector hook is pressed against the radially outer surface of the anti-wear device. It is meant that this is done at least in operation. In some embodiments, the ring is part of a compressor, preferably a high pressure compressor. It could also be a turbine ring. It can equally well be integrated in a single or dual flow turbomachine.

The present disclosure also relates to a turbomachine, comprising a turbomachine ring according to any one of the preceding embodiments.

The present disclosure also relates to a method of repairing a turbomachine ring, the turbomachine ring comprising a support, substantially cylindrical, having a front surface in which is formed a notch, said notch having been at least partially eroded and one or more sectors forming a ring configured to materialize an air stream section, each sector comprising a hook portion projecting toward the support and engaging in the notch of the support, the repair method comprising the following steps: machining of the inner walls of the notch; placing an anti-wear device, having a U-shaped portion and a tongue portion, in the notch thus machined; fixing the tab portion of the anti-wear device on the front surface of the support.

In some embodiments, the anti-wear device is in accordance with any of the embodiments set forth above.

In the present description, the terms "axial", "radial", "tangential", "proximal", "distal" and their derivatives are defined relative to the main axis of the turbomachine; the term "axial plane" a plane passing through the main axis of the turbomachine and "radial plane" a plane perpendicular to this main axis; a "frontal" surface is part of a radial plane; finally, the terms "upstream" and "downstream" are defined with respect to the flow of air in the turbomachine.

The above characteristics and advantages, as well as others, will become apparent on reading the following detailed description of exemplary embodiments of the proposed turbomachine ring and method. This detailed description refers to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are schematic and are intended above all to illustrate the principles of the presentation.

In these drawings, from one figure (FIG) to another, identical elements (or parts of element) are identified by the same reference signs. In addition, elements (or parts of elements) belonging to different exemplary embodiments but having an analogous function are indicated in the figures by incremented numerical references of 100, 200, etc.

FIG 1 is a sectional plane of a turbomachine according to the disclosure.

FIG 2 is a sectional view of a first example of a turbomachine ring.

FIG 3 is an enlargement of zone III of FIG 2.

FIG 4 is a sectional view of the anti-wear device of the first example.

FIG. 5 illustrates a second example of an anti-wear device.

DETAILED DESCRIPTION OF EXAMPLE (S) OF REALIZATION

In order to make the presentation more concrete, examples of turbomachine rings are described in detail below, with reference to the accompanying drawings. It is recalled that the invention is not limited to these examples.

FIG 1 shows, in section along a vertical plane passing through its main axis A, a single-jet turbojet 1 according to the presentation. It comprises, from upstream to downstream according to the circulation of the air flow, a low-pressure compressor 3, a high-pressure compressor 4, a combustion chamber 5, a high-pressure turbine 6, and a low-pressure turbine 7.

FIG 2 illustrates a portion of the stator of the high pressure compressor 4. In this figure, two compressor rings 30 according to a first embodiment are visible. Each compressor ring 30 comprises an upstream ring support 31m and a downstream ring support 31v, which are generally cylindrical and integral with the compressor housing 4: they each form a stream wall facing a bladed wheel. Each compressor ring 30 further comprises a ring sector ring 32 fixed on the ring supports 31m, 31v: they complete the air vein wall of the compressor 4 and carry blades 32a.

Each ring sector 32 is fixed on the ring supports 31m, 31v by means of attachment devices 33m and 33v provided at each axial end of the ring sector 32.

More specifically, each ring sector 32 comprises at each of its axial ends a hook 34 extending towards the adjacent support 31m, 31v and penetrating into a notch 35 of the support 31m, 31v.

As best seen in FIG 3, the notch 35 is formed in the front surface 36 of each support 31m, 31v: it extends continuously in the circumferential direction; its radially outer 35s and radially inner walls 35p are parallel.

An anti-wear device 40 is put in place in this notch 35. The anti-wear device 40, visible in FIG 4 in its initial state at rest, comprises a U-shaped portion 41 and a tongue portion 42. The anti-wear device 40 is an arcuate profile extending continuously and invariant in the circumferential direction: in FIG. 4, it is shown in section along a transverse plane, that is to say a plane axial in the reference of the turbomachine 1. In this example, the anti-wear device 40 is sectored, each sector extending over an arc of the same length; however, in other examples, it could be completely annular, split or not. In the present example, the anti-wear device 40 is made of a nickel-based and / or cobalt-based alloy with an anti-wear coating: it has a hardness lower than both the support 31m, 31v and the hook 34 of sector 32.

The U-shaped portion 41 comprises a radially outer wall 41d, a bottom wall 41f and a radially inner wall 41p arranged substantially U-shaped relative to each other. More specifically, the bottom wall 41f extends the radially outer wall 41d orthogonally. In contrast, the radially inner wall, extending the bottom wall 41f, forms a non-zero angle with respect to the direction of the radially outer wall 41d, that is to say the axial direction. In the present example, this angle l is about 12 °. The tongue portion 42 comprises for its part a single wall extending the radially inner wall 41p of the U-shaped portion 41: it forms an angle m with respect to the normal direction to the radially outer wall 41d, that is, ie with respect to the radial direction. In the present example, this angle m is about 12 °.

The U-shaped portion 41 is engaged in the notch 35 while the tab portion 42 is pressed and fixed against the radially inner zone 36a of the end surface 36 by means of weld spots 37 made by capacitor. As the distance between the ends of the radially outer 41d and radially inner wall 41p of the U-shaped portion 41 of the anti-wear device 40 is greater than the width of the notch 35, the U-shaped portion 41 is held under elastic stress within of the notch 35 and its radially outer wall 41d is elastically pressed against the radially outer surface 35d of the notch 35. In addition, the lengths of the radially outer wall 41d and radially inner 41p of the U-shaped portion 41 of the anti-rotation device. 40 are less than the depth of the notch 35 so that a space 38 remains between the bottom wall 41f of the U-shaped portion 41 and the bottom 35f of the notch 35.

It is noted that the hook 34 of the sector 32 enters the notch 35 protected by the anti-wear device 40 and is in the pressed position against the radially outer wall 41d of the U-shaped portion 41 of the anti-wear device 40 during the operation of the turbomachine 1, a space being left between the hook 34 and the bottom walls 41f and radially internal 41p of the U-shaped portion 41 of the anti-wear device 40.

An example of a turbomachine repair method according to the disclosure will now be described. It aims to repair a turbomachine 1 in which the notch 35 of one or more supports 31m, 31v of the high pressure compressor 4 has been worn and degraded following the friction of the hook 34 of a sector 32 in the latter. Concretely, in such a worn notch, the dimensions of the notch and the surface condition of its internal walls are degraded.

The repair method then comprises a step of machining the internal walls of the worn notch to a depth sufficient to eliminate defects and smooth the internal walls so as to obtain the original ribs at a set shrinkage, for example 0.2 mm or 0.4 mm.

An anti-wear device 40 as described above, and whose thickness of the walls of the U-shaped part corresponds to the depth of this determined shrinkage, is then inserted into the notch 35 thus machined in order to restore his initial ribs.

The tab portion 42 of the anti-wear device 40 is then fixed on the radially inner zone 36a of the front surface 36 by solder points 37 made by capacitor discharge.

The compressor ring 30 is thus repaired.

Once the anti-wear device 40 thus installed, the hook 34 of the sector 32 wears the anti-wear device 40 but no longer damages the notch 35 of the support 31m, 31v.

Therefore, if the anti-wear device 40 reaches a level of excessive wear, simply remove it and replace it with a new anti-wear device 40 to repair the compressor ring 30. This can be done very easily by inserting a tool into the space 38 located between the anti-wear device 40 and the bottom 35f of the notch 35 and by levering to break the weld points 37 step by step. The new anti-wear device 40 can then be put into place in the notch 35 and fixed on the front surface 36 in place of the used anti-wear device 40.

FIG. 5 illustrates a second example of a turbomachine ring 130. This second example is entirely analogous to the first example, except that the anti-wear device 140 is different.

In this second example, the anti-wear device 140 comprises a base element 149 and an additional element 159. The base element 149 is shaped in a manner quite similar to the anti-wear device 40 of the first example. it is only its thickness is lower.

The additional element 159 is an arcuate profile extending continuously and invariantly in the circumferential direction: in FIG. 5, it is shown in section along a transverse plane, that is to say an axial plane in the referential of the turbomachine. It takes a U-shape complementary to the U-shaped portion 141 of the base element 149. Thus, at rest, the radially inner wall 15 lp of the additional element 159 also forms an angle l with the direction of its radially outer wall 15 ld, that is to say with the axial direction, so that the additional element and maintained in elastic compression at within the base element 149 when the latter is engaged in the notch 135 of the support 131v.

In the present example, the base element 149 of the anti-wear device 140 is made of an alloy based on nickel and / or cobalt while the additional element 159 is made of a nickel-based alloy and or cobalt: the additional element 159 has a hardness lower than both the base member 159 and the hook 134 of the sector 132.

Although the present invention has been described with reference to specific exemplary embodiments, it is obvious that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the revendications. In particular, individual features of the various embodiments illustrated / mentioned can be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

It is also obvious that all the features described with reference to a method are transposable, alone or in combination, to a device, and conversely, all the features described with reference to a device can be transposed, alone or in combination, to a method.

Claims

1. Turbomachine ring, comprising

a substantially cylindrical support (31v) arranged to extend around an axial direction (A) of the turbomachine, the support (31v) having a front surface (36) in which a notch (35) is formed, notch (35) comprising a radially inner surface (35i), a bottom (35f) and a radially outer surface (35d),

one or more sectors (32) forming a ring configured to materialize an airstream section, each sector (32) comprising a hook portion (34) projecting toward the carrier (31v) and engaging with the notch (35) of the support (31v), and

an anti-wear device (40) having a U-shaped portion (41) provided in the notch (35) of the support (31v) and plated at least against the radially outer surface (35d) of the notch (35), and a tongue portion (42) continuously extending the U-shaped portion (41), plated and secured against the front surface (36) of the support (31v).

The ring of claim 1, wherein the U-shaped portion (41) of the anti-wear device (40) is under elastic stress.

Ring according to claim 1 or 2, wherein the tongue portion (42) of the anti-wear device (40) is under elastic stress.

Ring according to any one of claims 1 to 3, wherein a space (38) is left between the U-shaped portion (41) of the anti-wear device (40) and the bottom (35f) of the notch (35). of the support (31v).

Ring according to any one of claims 1 to 4, wherein the tab portion (42) of the anti-wear device (40) is fixed on the front surface (36) of the support (31v) by welding spots. (37).

Ring according to claim 5, wherein the soldering points (37) are of the type obtained by capacitor discharge.

Ring according to any one of claims 1 to 6, wherein the thickness of the anti-wear device (40) is between 0.1 mm and 1 mm, preferably between 0.2 mm and 0.6 mm. .

8. Ring according to any one of claims 1 to 7, wherein the anti-wear device (40) has a hardness less than that of the support (31v) and lower than that of the hook (34) of the sector (32).

The ring according to any one of claims 1 to 8, wherein the anti-wear device (140) comprises a base member (149), in the form of a channel having a U-shaped portion (141) and a tongue portion (142), and an additional U-shaped member (159) provided within the U-shaped portion (141) of the base member (149),

wherein the additional member (159) has a hardness less than that of the base member (149).

Ring according to claim 9, wherein the additional element (159) takes the form of a section distinct from the base element (149), or a coating deposited on the base element (149). , or a layer forming the same profile with the base member (149).

11. Turbomachine, comprising a turbomachine ring (30) according to any one of the preceding claims.

12. A method of repairing a turbomachine ring, the turbomachine ring (30) comprising

a substantially cylindrical support (31v) having a front surface (36) in which a notch (35) is formed, said notch (35) having been at least partially eroded, and

one or more sectors (32) forming a ring configured to materialize an airstream section, each sector (32) comprising a hook portion (34) projecting toward the carrier (31v) and engaging with the notch (35) of the support (31v),

the repair method comprising the following steps:

machining the inner walls of the notch (35);

providing an anti-wear device (40), having a U-shaped portion (41) and a tongue portion (42), in the thus-machined notch (35); attaching the tab portion (42) of the anti-wear device (40) to the front surface (36) of the carrier (35).