Non-asymmetrical crankcase treatment

Abstract

Non-Asymmetrical Housing Treatment The invention relates to a turbomachine housing comprising: - through-holes (501) cut into the thickness of the housing (11) from an internal surface (Sint) of the housing and distributed angularly around the circumference of said housing, - a sealing element (101) present in each of the through-holes, the sealing element being radially movable within the through-hole between a sealing position and an opening position; - at least one movable ring portion (202) connected to a plurality of sealing elements by a mechanical linkage transforming an axial displacement of the movable ring portion into a radial displacement of each of the sealing elements connected to the movable ring portion; - an axial displacement element (301) for the different movable ring portions. Figure for the abstract: Fig. 2.

Description

Title of the invention: Non-asymmetrical casing treatment Technical field

[0001] This presentation concerns the field of turbomachine casings and more precisely the geometries of such elements. Prior art

[0002] Aeronautical turbomachines repeatedly comprise a set of rotating blades, inside a casing.

[0003] The casings of aeronautical turbomachines ensure the sealing of the air stream with the exterior of the turbomachine and also contain blade debris in the event of accidental rupture of the latter.

[0004] The clearance existing between the rotating blade and the casing degrades the efficiency of the turbomachine. Nevertheless, such clearance is essential so that the rotational movement of the blade can take place without friction.

[0005] Furthermore, in order to improve the operability areas of the engine and avoid the occurrence of the pumping phenomenon, it is known to provide slots, called casing treatment, in the casing, radially above the blades.

[0006] Crankcase treatment increases the overall consumption of the engine but ensures engine operability under all conditions. In other words, crankcase treatment is therefore desirable when maximum engine operability is desired but offers unused gain at the cost of significant excess consumption during normal engine operation.

[0007] Solutions are proposed in the prior art for providing openings at the top of the blades, called "casing treatment", the opening of which is controlled. The casing treatment can then be operational, i.e. the openings are open, when this is desired given difficult operating conditions for the engine (during very poor weather conditions for example) but closed when the conditions of use do not require the openings to be open.

[0008] The casing treatment makes it possible to modify the geometry of the casing in order to change the dynamic flow of air between the casing and the tip of the blades.

[0009] To further increase the potential gain of sump treatments, it would be desirable for them to be adaptable to the topology of flows close to the pumping phenomenon in order to be able to reduce losses, while offering advantages in terms of operability.

[0010] Of course, the crankcase treatments must also allow operation with a smooth vein during normal engine operation. Statement of the invention

[0011] The invention aims precisely to respond to the problems explained above.

[0012] It thus relates, according to one of its aspects, to a turbomachine casing comprising: - through openings hollowed out in the thickness of the casing from an internal surface of the casing and distributed angularly around the circumference of said casing, - a closing element present in each of the through openings, the closing element being radially movable in the opening between a closing position and an open position; - at least one portion of movable crown connected to a plurality of closure elements by a mechanical connection transforming an axial displacement of the portion of movable crown into a radial displacement of each of the closure elements connected to the portion of movable crown; - an axial displacement member for the different portions of the movable crown.

[0013] This embodiment makes it possible to meet the primary objective of the casing treatment which is to allow the presence of slots above the blades when necessary.

[0014] Furthermore, the embodiment according to the invention allows, unlike the solutions of the prior art, to have a more or less deep slot depending on the particular needs of the engine speed.

[0015] In fact, the closing element is movable between a closing position and an opening position, but it also passes through all the positions between these extreme positions.

[0016] A small movement of the moving member of the movable crown therefore allows the partial opening of the closing elements.

[0017] It is thus possible, for each engine speed encountered, to choose the position of the closing elements which offers the best compromise between the minimum expected performance and a limitation of the excess consumption caused by this opening.

[0018] Finally, the proposed embodiment offers precise and reliable control of the openings because the position of the closure element is a function of the axial displacement of the movable crown portion to which the closure element is attached, this displacement being able to be controlled simply.

[0019] The openings are said to be "through" in the sense that they pass right through the casing. However, it must be understood that the opening is closed by the closing element, so that at no time during the operation of the casing treatment is the opening completely open.

[0020] In particular, even in its open position, the closing element only allows a partial opening of the through opening, which can be seen as a hole in the casing, but which does not allow passage through it.

[0021] In one embodiment, each opening is invariant in the radial direction. It is thus understood that in any plane perpendicular to the radial direction, the opening will have an identical projection.

[0022] In one embodiment, the openings may all be of the same dimensions.

[0023] In one embodiment, the openings are not inclined and the openings are then comparable to straight blocks, the edges of which are parallel to one of the axial, radial or circumferential directions.

[0024] In one embodiment, the through openings may have an inclination of between 0° and 45° relative to the radial direction and / or an inclination of 0° to 45° relative to the axial direction of the casing.

[0025] The inclination is then understood as the angle formed by the edges of the opening with the radial, axial or circumferential direction which would be parallel to them if the opening were a straight block whose surface on the casing was identical.

[0026] Preferably, the through openings have an inclination in the radial direction only, the inclination being between 0° and 45°.

[0027] Inclined openings make it possible to adjust the expected flow by opening, even partially, the closure element.

[0028] Indeed, the air coming into contact with the openings generally has a high tangential speed, and it may be preferable for reasons of air flow to have through openings which are inclined.

[0029] Preferably, the through openings are not inclined in the axial or circumferential direction.

[0030] In one embodiment, the through openings are arranged in the casing opposite the upper end of turbomachine blades, preferably of moving turbomachine blades.

[0031] The expression "facing" used for the openings relative to the blades is intended to mean that the through openings are arranged radially above the turbomachine blades. An opening will be said to be "facing" a blade when at least part of the opening is located radially above a portion of the blade.

[0032] In one embodiment, the through openings are arranged opposite blades of a mobile fan blade or blades of a mobile compressor blade, for example a low pressure compressor or a high pressure compressor.

[0033] In one embodiment, the number of through openings may be between 50 and 400.

[0034] Indeed, the modification of the air flow is influenced by the total number of openings present on the circumference of the casing. Also, the modification of the air flow is a function of the number of through openings per blade of the moving blade that said casing surrounds.

[0035] In one embodiment, the average number of through openings per blade of the moving blade included in the turbomachine casing may be between 3 and 10, preferably between 3 and 8.

[0036] It is specified that this number can take any value between 3 and 8 and it is not at all necessary for this number to be an integer.

[0037] Optimizing the average number of through-openings per blade of the moving blade that the casing surrounds makes it possible to configure as precisely as desired the expected performance of the through-openings on increasing the operability of the turbomachine.

[0038] In one embodiment, the through openings may be arranged above the moving blades of the turbomachine.

[0039] In such an embodiment, the through openings may furthermore be arranged opposite the leading edge of the blades of the blading which surrounds the turbomachine casing.

[0040] Indeed, it has been found that it is by arranging the through openings in the casing in this way that the latter have the most marked effect on increasing the operability of the turbomachine.

[0041] In one embodiment, the movable crown comprises between 2 and 4 movable crown portions.

[0042] This embodiment offers an excellent compromise between ease of manufacture and safety of use.

[0043] In one embodiment, all of the movable crown portions form a single movable crown, in other words all of the closure elements are connected to a single movable crown.

[0044] However, for reasons of reliability and ease of assembly, it is generally preferred to split the movable crown into several movable crown portions, each of the portions actuating a plurality of closure elements.

[0045] Indeed, the more portions of movable crown there are, the less the malfunction of one of them is detrimental to the operability of the casing treatment as a whole.

[0046] The fewer portions of movable crowns there are, the less complex the control and maintenance of the latter becomes.

[0047] The proposed embodiment offers the best compromise between these two effects, which are reliability on the one hand and ease of assembly on the other.

[0048] In the remainder of the application, it will be understood that “moving crown” can replace the expression “portion of moving crown” insofar as the splitting of a single moving crown into a plurality of portions of moving crowns as well as the associated technical advantages have just been described.

[0049] In one embodiment, the axial displacement member of the movable crown is chosen from a hydraulic piston and an electric actuator.

[0050] These two solutions have advantages both in terms of integrability in a turbomachine casing and in terms of control and servo-control of the axial position of the moving crown.

[0051] In one embodiment, the casing comprises a plurality of connecting elements secured to the movable crown, each of the connecting elements having a surface inclined in the radial direction and in which a pin secured to each closure element rests on a surface inclined in the radial direction of a separate connecting element.

[0052] This embodiment makes it possible to simply ensure a mechanical connection between the movable crown and the closure element in which an axial translational movement of the movable crown is transformed into a radial movement of the integral closure elements moved by said movable crown.

[0053] Indeed, the inclined surface allows a displacement of the pin and consequently of the closure element which has a component in the radial direction.

[0054] In an embodiment complementary to that which has just been described, the connecting element secured to the movable crown forms a ring having an inclined surface and the pin secured to the closing element is included in said ring formed by the connecting element.

[0055] The inventors have found that this embodiment minimizes the number of intermediate elements to ensure the transformation of the axial movement of the movable crown into a radial movement of the closure elements, which ensures minimal weight gain of the device, and ultimately reduced fuel consumption of the turbomachine.

[0056] Finally, the pin secured to the closure element cannot be detached from the connecting element secured to the movable crown since it is caught in a ring.

[0057] In an embodiment complementary to that which has just been described, the pin secured to the closure element is included between a first leg and a second leg themselves secured to the closure element.

[0058] This embodiment makes it possible to ensure excellent transformation of the axial displacement of the movable crown into a radial displacement of the closure elements.

[0059] Furthermore, it is thus simple to separate the closure element from the movable crown, because it is sufficient to release the pin from the ring by removing one or the other of the legs. This simplifies the inspection or maintenance of a turbomachine casing as described.

[0060] According to another of its aspects, the invention also relates to a turbomachine comprising a casing as described above.

[0061] Such a turbomachine has satisfactory operability in all flight regimes, and this at the cost of controlled and optimized fuel overconsumption compared to turbomachines whose casing treatments are according to configurations of the prior art.

[0062] According to yet another of its aspects, the invention relates to an aircraft comprising a turbomachine as described above.

[0063] Such an aircraft offers satisfactory operability in all flight regimes and this at the cost of controlled and optimized overconsumption of fuel compared to aircraft whose turbomachines include casing treatments according to configurations of the prior art. Brief description of the drawings

[0064] [Fig-1] [Fig.l] is a schematic representation of a turbomachine.

[0065] [Fig.2] [Fig.2] represents a perspective view of a turbomachine casing in one embodiment of the invention.

[0066] [Fig.3] [Fig.3] represents a sectional view of a turbomachine casing in an embodiment of the invention in which the closure element is in the closed position.

[0067] [Fig.4] [Fig.4] represents a sectional view of a turbomachine casing in an embodiment of the invention in which the closure element is in the open position.

[0068] [Fig.5] [Fig.5] schematically represents the view adopted for figures 6 to 8.

[0069] [Fig.6] [Fig.6] schematically represents a non-inclined opening.

[0070] [Fig.7] [Fig.7] schematically represents an opening of a mode of rea inclined lization in the axial direction.

[0071] [Fig.8] [Fig.8] schematically represents an opening of an embodiment inclined in the radial direction. Description of the embodiments

[0072] The invention is now described by means of figures, present for descriptive purposes to illustrate certain embodiments of the invention and which should not be interpreted as limiting the latter.

[0073] In particular, the figures are neither to scale nor even to relative scale, but are represented in such a way that they allow the invention to be understood.

[0074] [Fig.l] represents, in section along a radial plane passing through its main axis A, a double-flow turbojet 1. It comprises from upstream to downstream according to the circulation of the air flow, a fan 2, 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.

[0075] The turbomachine of [Fig. 1] further illustrates a casing 11, which surrounds the rotating blades of the low pressure compressor 3, the high pressure compressor 4, the high pressure turbine 6 and the low pressure turbine 7.

[0076] [Fig. 1] is a schematic representation and the casing 11 is not necessarily the same for all the rotating blades, contrary to what is shown in [Fig. 1].

[0077] Generally, a low pressure compressor 3, a high pressure compressor 4, a high pressure turbine 6 and a low pressure turbine 7 comprise a plurality of rotating blades.

[0078] To obtain the technical effects of the casing described above, through openings can be provided opposite one of the rotating blades of an element or opposite several, or even all, of the rotating blades of an element.

[0079] Similarly, in a given turbomachine, one or more, or even all, of the elements 3, 4, 6 and 7 may comprise through openings closed by closing elements as described above.

[0080] Preferably, the through openings are arranged opposite blades of a rotary blade of the low-pressure compressor 3, arranged opposite blades of a rotary blade of the high-pressure compressor 4 or even opposite blades of a rotary blade of a fan.

[0081] Throughout the application, the axial, circumferential and radial directions will be identified relative to the main axis A of the turbomachine as the directions of a cylindrical reference frame.

[0082] The axial direction will be understood as that extending along the main axis A of the turbomachine.

[0083] The circumferential direction will be understood as that extending around the main axis A.

[0084] The radial direction will be understood as the direction moving away from the main axis A in a plane perpendicular to the axis A.

[0085] [Fig.2] illustrates an embodiment representing a turbomachine casing 10 in one embodiment of the invention.

[0086] In the embodiment shown, the casing wall 11 comprises closing elements 101 which close through openings 501.

[0087] [Fig.2] represents the case illustrated in another view in [Fig.3].

[0088] As shown in [Fig.3] which will be described below, the element sealing element 101, is inserted into the through opening so that the casing 11 has aerodynamic continuity, despite the presence of the through opening 501.

[0089] The casing 11 further comprises a movable crown 202 which is integral with a plurality of connecting elements 201.

[0090] Each connecting element 201 has an inclined surface on which rests a pin 103 secured to the closing element 101.

[0091] In the embodiment shown, each connecting element 201 has an annular shape, that is to say forming a closed contour 204 around a central space 205, and the contour 204 of this annular shape makes it possible to enclose the pin 103 secured to the closing element 101.

[0092] The pin 103 rests on an inclined surface of the connecting element 201, which ensures that it can have a displacement component along the radial axis.

[0093] The pin 103 is included between a first leg and a second leg 102, themselves integral, here directly connected, to the closing element 101.

[0094] In the illustrated embodiment, the casing 11 further comprises a member for axial displacement of the movable crown 202.

[0095] In the embodiment shown, the axial displacement member of the movable crown 202 is a piston 301, for example a hydraulic piston, included in a housing 302.

[0096] The piston 301 is made integral with the movable crown by means of a connecting element 203 which is directly connected both to the piston 301 and to the movable crown 202.

[0097] The embodiment shown is only one embodiment of the invention, and it should not be considered that this embodiment is the only one allowing the technical effect to be obtained, in particular allowing partial opening between the open position and the closed position.

[0098] Nevertheless, and as explained above, this embodiment also presents specific advantages over other possible embodiments.

[0099] In the embodiment shown, the movable crown 202 is a portion of a movable crown and is connected to only four visible closure elements 101.

[0100] It should however be understood as explained above that the movable crown 202 or more precisely the movable crown portions can each comprise more than four closing elements 101.

[0101] [Fig.2] further illustrates that the through openings are distributed angularly along the casing 11.

[0102] Preferably, the through openings are of identical dimensions and are distributed equally along the circumference of the casing.

[0103] This embodiment ensures better predictability of aerodynamic behavior. dynamic caused by the opening, even partial, of the through openings.

[0104] Figures 3 and 4 show in more detail how the mechanical connection between the movable crown 202 and the closure element 101 effectively makes it possible to transform an axial displacement of the movable crown 202 into a radial displacement of each of the closure elements 101.

[0105] Figures 3 and 4 are sectional views of the casing of [Fig.2], and the same elements are recalled therein by identical numerical references.

[0106] In [Fig.3], the closure element is in the closure position, also called the closing position.

[0107] As is schematically represented by the blade 401 shown below the internal surface Sint of the casing 11, the through opening 501 is in fact completely closed by the closing element which ensures that the internal surface Sint of the casing 11 is aerodynamically continuous.

[0108] The internal surface Sint of the casing is the surface of the casing 11 closest to the moving blade that the casing 11 surrounds, is here represented only by the tip of the blade 401.

[0109] [Fig.4] illustrates the shutter element in an open position.

[0110] Comparison of Figures 3 and 4 illustrates how the axial movement of the organ axial displacement of the movable crown 202, here the piston 301, is transformed into a radial displacement of the closing elements 101.

[0111] In one embodiment, the through openings 501 may be inclined relative to the radial direction of the casing.

[0112] As can be observed by comparing Figures 3 and 4, the axial movement of the piston 301 in its housing 302 causes an axial displacement of the movable crown 202, the housing of the piston 302 being held fixed by means not shown.

[0113] In one embodiment, the housing of the piston 302 can be connected directly or indirectly to the casing 11, for example by gluing, screwing or any other removable or non-removable connection means.

[0114] In the embodiment shown, the element 201 secured to the movable crown 202 is moved axially, which causes a vertical movement of the pin 103 which rests on an inclined surface 204b in the radial direction.

[0115] The pin 103 cannot in fact reproduce the axial movement of the movable crown, because its movement is constrained by the ring 204 on the one hand by the inclined surface 204b and on the other hand by the upper part 204a of the element 201.

[0116] In other words, since the movement of the pin 103 can only take place in the interior 205 of the ring 204 of the element 201, part of the horizontal displacement of the movable crown 202 is transferred in the radial direction.

[0117] Finally, since the pin 103 is secured to the closure element 101, via the tabs 102, the radial movement of the pin is reproduced by the closing element 101, and the through opening 501 is thus released.

[0118] It is particularly advantageous to have through openings 501, that is to say openings which pass right through in the radial dimension the casing 11 because this makes it possible to arrange all of the elements of the device on an external portion of the turbomachine casing.

[0119] The through opening does not, however, necessarily need to have a constant width in the radial direction of the casing 11.

[0120] In one embodiment, a portion of the opening may be crossed by the tabs 102 secured to the closure element.

[0121] It is recalled that the figures are not to scale. In particular, the spaces between the closure element 101 and the casing 11 are not representative, and are present only to allow the distinction between the closure element 101 and the casing 11.

[0122] In one embodiment, the casing further comprises sealing means to ensure that in the closed position, the air included inside the casing cannot pass through the through openings 501.

[0123] Figures 5 to 8 are intended to characterize what is meant by the orientation of the through openings.

[0124] [Fig.5] shows a front view of a turbomachine casing 11 surrounding a blading composed of moving blades 401.

[0125] The casing 11 further comprises a through opening 501, the closing element is not shown.

[0126] [Fig.5] illustrates the viewpoint of Figures 6 to 8, represented by the eye in [Fig.5].

[0127] [Fig.6] illustrates a through opening 501 in a casing 11 when this the latter is not inclined in any direction.

[0128] In such a case, its edges are parallel to the axial DA, radial DR and circumferential Dc directions of the cylindrical reference frame.

[0129] By comparison, [Fig.7] illustrates a through opening 501 inclined in the axial direction.

[0130] Indeed, the edges of the opening 501 which would be parallel to the axial direction DA if the opening were a straight block have an angle aA with the axial direction DA.

[0131] In one embodiment this inclination can be between 0° and 45°.

[0132] As shown, the inclination of an opening relative to the axial direction DA is preferably understood to take place in a plane comprising the axial direction DA and the circumferential direction Dc.

[0133] [Fig.8] illustrates an inclination only in the radial direction.

[0134] In one embodiment this inclination can be between 0° and 45°.

[0135] As shown, the inclination of an opening relative to the radial direction DR is preferably understood to take place in a plane comprising the radial direction DR and the circumferential direction Dc.

[0136] The edges of the opening 501 which would be parallel to the radial direction DR if the opening were a straight block have an angle aR with the radial direction DR.

[0137] Within the meaning of the invention, the inclination of the through opening can be understood in more than one direction, and figures 7 and 8 shown are the embodiments which allow an easy understanding of what the inclination of the openings is.

[0138] In an embodiment not shown, the openings may have an inclination in the radial and / or axial direction of between 0° and 45°.

[0139] In one embodiment, which is shown in [Fig.8], the through openings 501 are inclined relative to the radial direction DR, but not relative to the circumferential direction Dcni the axial direction DA.

[0140] In other words, edges of the opening 501 are parallel to the circumferential direction and to the axial direction, but those which are not present with the radial direction an angle between 0° and 45° in a plane comprising the radial direction and the circumferential direction.

[0141] This embodiment in fact makes it possible to optimize the aerodynamic behavior of the through openings 501 and to take into account the high circumferential speed of the air due to the movement of the rotating blades surrounded by the casing 11.

[0142] Furthermore, this makes it possible to lengthen the dimension of the through openings 501, and therefore to propose an even greater modification of the operability of the engine at a constant number of openings compared to through openings 501 arranged axially. Having larger openings makes it possible to further increase the operability over a wider range with a reduced weight of the device, which represents a significant gain for the entire turbomachine.

[0143] In one embodiment, the orientation of the through openings 501 may be inclined from 0° to 45° relative to the radial direction.

[0144] In such a case, the displacement of the closure element 101 does not take place strictly in the radial direction.

[0145] It is nevertheless understood that a movement will be said to be radial and respectively axial or circumferential, if it includes a non-zero component along the radial direction, and respectively axial or circumferential.

[0146] Furthermore, the technical effect of allowing easy control of the position of the closure element remains obtained.

Claims

Claims

1. Aircraft turbomachine casing comprising: - through openings (501) hollowed out in the thickness of the casing (11) from an internal surface (Sint) of the casing and distributed angularly on the circumference of said casing, - a closure element (101) present in each of the through openings, the closure element being radially movable in the through opening between a closure position and an open position; - at least one movable crown portion (202) connected to a plurality of closure elements by a mechanical connection transforming an axial displacement of the movable crown portion into a radial displacement of each of the closure elements connected to the movable crown portion; - an axial displacement member (301) of the different movable crown portions.

2. Turbomachine casing according to claim 1, in which the through openings (501) have an inclination of between 0° and 45° relative to the radial direction of the casing.

3. Turbomachine casing according to claim 1 or 2, in which the through openings are arranged opposite the leading edge of the blades of the blading that the turbomachine casing is intended to surround.

4. Turbomachine casing according to any one of claims 1 to 3, in which the through openings are arranged opposite blades of a mobile fan blade or blades of a mobile compressor blade, for example a low pressure compressor or a high pressure compressor, which the turbomachine casing is intended to surround.

5. Turbomachine casing according to any one of claims 1 to 4, in which the axial displacement member (301) of the movable crown (202) is chosen from a hydraulic piston and an electric actuator.

6. Turbomachine casing according to any one of claims 1 to 5, which comprises a plurality of connecting elements (201) integral with the movable crown (202), each of the connecting elements having an inclined surface (204b) in the radial direction and in which a pin (103) integral with each closure element rests on a surface inclined in the radial direction of a separate connecting element.

7. Turbomachine casing according to claim 6, in which the connecting element (201) secured to the movable crown forms a ring (204) having an inclined surface (204b) and in which the pin secured (201) to the closure element is included in said ring formed by the connecting element.

8. Turbomachine casing according to claim 7, in which the integral pin (103) of the closure element is between a first tab and a second tab (102) themselves integral with the closure element (101).

9. Turbomachine (1) comprising a casing according to any one of claims 1 to 8.

10. Aircraft comprising a turbomachine according to claim 9.

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