Aircraft turbine housing and method of manufacturing the same

Abstract

The invention relates to a casing (3) for an aircraft turbine, comprising: an annular shell (9) extending around an axis A and made of a composite material comprising fibers woven and embedded in a resin; an annular layer (4) of abradable material extending inside the shell around the axis A and obtained by spreading and polymerizing a slurry; and a support plate (10) extending around the axis A and interposed between the shell and the abradable layer.

Description

Technical Field

[0001] The present invention relates to a casing for an aircraft turbomachine, in particular for a fan, and to a method for producing said casing. Background Art

[0002] The prior art includes in particular documents FR-A1-2 997 725, FR-A1-2 997 726, FR-A1-3 005 100, FR-A1-3 048 018, FR-A1-3 051 828, EP-A1-3 310 495 and FR-A1-3 060 7438.

[0003] Figure 1 It is a partial schematic diagram of a fan of an aircraft turbine.

[0004] In conventional manner, a turbomachine comprises, from upstream to downstream (ie in the direction of flow of the gas flow), a fan, one or more compressors, a combustion chamber, one or more turbines and nozzles for ejecting the combustion gases leaving the one or more turbines.

[0005] The fan 1 comprises an impeller 2 surrounded by a fan housing 3, also called a retaining housing, due to its function of retaining the blades in the event of blade breakage or debris entering the fan.

[0006] like Figure 2 As shown, the fan casing 3 generally comprises an annular envelope 9 having an axis of rotation A, which extends around the fan blades 2 of the turbine. This envelope comprises an annular connecting flange 3 ', 3 "at each of its axial ends. These flanges 3 ', 3 "are used to attach the casing 3 to the annular wall of the nacelle of the turbine.

[0007] Figure 3 is a schematic cross-sectional view showing a fan case 3 according to the prior art.

[0008] The fan casing 3 is connected upstream to the air inlet shroud 5 and downstream to the intermediate casing shroud 6. The casing also carries an upstream acoustic panel 7 and a downstream acoustic panel 8. The fan casing 3 also includes an annular layer 4 of abradable material located on the inner annular surface of the containment shell and between the upstream panel 7 and the downstream panel 8.

[0009] In addition to the holding function, the fan housing 3 is also designed to:

[0010] - Ensure the continuity of the aerodynamic duct using an annular layer of abradable material;

[0011] - ensuring mechanical continuity (force and torque) between the air inlet sleeve 5 and the intermediate housing shroud 6;

[0012] - Realize the connection between boards 7, 8 and layer 4;

[0013] - Enables attachment to known devices and the bracket itself;

[0014] - Comply with fire and spill regulations;

[0015] -Achieve current continuity for lightning protection, etc.

[0016] As in Figure 4 As can be seen in the larger cross-sectional view of FIG, wearable support plates 10 are inserted between the cladding 9 and the layer 4. These plates 10 are generally formed of a sandwich structure comprising a skin layer 10b covered with a honeycomb layer 10c of the honeycomb type (i.e., with open cells). The skin layer 10b extends between the cladding 9 on one side and the honeycomb layer 10c on the other side, and the glue layer 10a extends between the honeycomb layer 10c and the layer 4 on the other side.

[0017] The plate 10 is bonded to the inner surface of the cladding 9 and the abradable layer 4 is typically obtained by spreading and polymerizing a slurry consisting of a mixture of premixed components.

[0018] Layer 4 is formed, for example, from a two-component, dense epoxy resin filled with glass microspheres. This abradable layer 4 ensures a minimum clearance between the tips of the fan blades 2 and the housing 3. During the first revolution of the fan, these blades 2 wear away the layer, adjusting the clearance between the blade tips and layer 4 in a manner optimized for a given engine. Thus, by adapting the layer's trajectory to the individual clearances of the blades of each engine, engine efficiency is guaranteed.

[0019] In current technology, the abradable layer 4 has a relatively large thickness, reaching up to 8 mm. When mixing viscous components, special care must be taken to limit porosity caused by mixing and degassing, while ensuring good mixing of the two components. Once the deposit is formed, polymerization can be carried out at room temperature or in an oven. Porosity often develops after polymerization, and localized repairs may be necessary.

[0020] Although the deposition method has been optimized to reduce porosity in the abradable layer, some porosity still exists due to outgassing of the material or the deposition method below the visible surface.

[0021] For this reason, during installation, acceptance, or operational testing, some engines may exhibit porosity after running in. Furthermore, because the abradable layer material has low cohesion, it is susceptible to localized losses due to underlying porosity and cracking.

[0022] The present invention proposes a simple, effective and economical solution to at least some of the problems of the prior art. Summary of the Invention

[0023] According to a first embodiment, the invention relates to an aircraft turbine casing comprising:

[0024] an annular casing extending around the axis A and made of a composite material comprising fibers woven and embedded in a resin,

[0025] an annular layer of abradable material extending inside the shell around the axis A and obtained by spreading and polymerizing a slurry, and

[0026] a support plate extending around the axis A and inserted between the cladding and the abradable layer,

[0027] It is characterized in that the layer is associated with at least one fiber reinforcement.

[0028] In order to solve the problems of low cohesion, sensitivity to drawing and cracking of the material during use, the present application proposes to reinforce it with one or more fiber reinforcements to improve its cohesion.

[0029] The housing according to the present application may include one or more of the following features, which may be considered independently or in combination with each other:

[0030] - reinforcing fibers (lengths of, for example, between 0.5 mm and 20 mm) are dispersed in the slurry and the abradable layer to solve the problem of porosity or high material losses (in addition to porosity), the idea being to add fiber reinforcement in the form of fibers (for example, glass, aramid or carbon) during the mixing of the components of the abradable layer, depending on the effect on the density of the material; this results in a resin that is more resistant to tensile, compressive and shear stresses in all directions;

[0031] - reinforcing loops or fabrics are embedded in the abradable layer or inserted between the layer and the plate;

[0032] the plates are separated from each other by gaps filled with the slurry, at least some of the coils or fabrics covering these gaps; as to the problem of cracking, fiber-reinforced tapes (woven or not) can be used in the connecting areas of the plates to prevent cracking of the abradable layer; for example, these tapes can be woven together to promote their wetting by the abradable layer;

[0033] - A foam layer is inserted between the plate and the abradable layer; in order to overcome the problems of mechanical strength and porosity, it is also considered to replace most of the thickness of the abradable layer with a foam layer (for example with an adhesive or by bonding through the abradable layer on the plate); this alternative solution can reduce the amount of abradable slurry used, thereby promoting the degassing of the material, which greatly reduces the number of pores; in addition, the foam can absorb the shear deformation of the connection area of these plates; in combination with the fibers as described above, the foam also increases the cohesive strength of the material, its wettability with the substrate, reduces the number of pores and reduces the cost of the abradable track; the remaining abradable layer can ensure the abradability of the support and thus ensure the gap with the top of the blade.

[0034] The invention also relates to an aircraft turbomachine comprising a casing as described above, in particular a casing extending around a fan of the turbomachine.

[0035] The present invention also relates to a method for manufacturing a housing as described above, wherein the method comprises the following steps:

[0036] - bonding the plate to the inner annular surface of the cladding,

[0037] - Preparing a slurry and spreading it on an inner annular surface (eg a plate) to form an abradable layer, the layer being associated with at least one fiber reinforcement.

[0038] The method may include one or more of the following features or steps, which may be considered independently or in combination with each other:

[0039] - mixing reinforcing fibers into the slurry before spreading it, or arranging reinforcing rings or reinforcing fabrics on the inner annular surface of the plate before spreading it;

[0040] - the slurry is spread on the inner annular surface of the foam layer previously bonded to the inner annular surface of the plate;

[0041] -The slurry is spread in a plurality of sub-steps, each sub-step comprising: depositing the slurry in the shape of a sphere on the inner annular surface, spreading the slurry on the surface to make its thickness uniform, extending the slurry over a predetermined angular segment of the surface, and then forming a chamfer at the edge of the slurry so that the slurry deposited and spread on the adjacent angular segment can cover the chamfered edge.

[0042] According to a second embodiment, the invention relates to an aircraft turbine casing comprising:

[0043] an annular casing extending around the axis A and made of a composite material comprising fibers woven and embedded in a resin,

[0044] an annular layer of abradable material extending inside the shell around the axis A and obtained by spreading and polymerizing a slurry, and

[0045] a support plate extending around the axis A and inserted between the cladding and the abradable layer,

[0046] Characterized in that the abradable layer is deposited on the inner annular surface of a foam layer, which itself is deposited on the inner annular surface of the plate.

[0047] The housing according to the present application may include one or more of the following features, which may be considered independently or in combination with each other:

[0048] - the thickness of the foam layer 18 is between 1 mm and 7 mm, preferably between 3 mm and 5 mm;

[0049] The sum of the thicknesses of the wearable layer and the foam layer is less than or equal to 10 mm, and preferably less than or equal to 8 mm;

[0050] - the foam layer is made of thermoplastic material;

[0051] -The density of the foam layer is 20Kg / m 3 Up to 100Kg / m 3 between;

[0052] - the abradable layer is associated with at least one fiber reinforcement chosen from reinforcing fibers and reinforcing coils or fabrics;

[0053] - The plates are separated from each other by gaps which are filled with said slurry, at least some of the rings or fabric covering these gaps.

[0054] The features of the two embodiments of the invention can naturally be combined together.

[0055] The invention also relates to an aircraft turbomachine comprising a casing as described above, in particular a casing extending around a fan of the turbomachine.

[0056] The present invention also relates to a method for manufacturing a housing as described above, wherein the method comprises the following steps:

[0057] - bonding the plate to the inner annular surface of the cladding,

[0058] - bonding the foam layer to the inner annular surface of the plate, and

[0059] - Prepare a slurry and spread the slurry on the inner annular surface of the foam layer.

[0060] Reinforcement fibers may be mixed into the slurry before it is spread.Alternatively or additionally, a reinforcement ring or fabric may be arranged on the inner annular surface before the slurry is spread on the surface.

[0061] According to a third embodiment, the invention relates to a method for producing an aircraft turbine casing, the casing comprising:

[0062] an annular casing extending around the axis A and made of a composite material comprising fibers woven and embedded in a resin,

[0063] - an annular layer of abradable material extending within said cladding, and

[0064] a support plate extending around the axis A and inserted between the cladding and the abradable layer,

[0065] Characterized in that the method comprises the following steps:

[0066] a) preparing a slurry by mixing at least two components,

[0067] b) depositing the slurry onto the inner annular surface of the plate,

[0068] c) spreading the slurry by means of at least one roller extending substantially parallel to the axis A and arranged to roll on guide rings arranged on both sides of the plate or cladding and coaxially therewith, so as to form an angular segment of the abradable layer extending over a predetermined angle about the axis A,

[0069] d) forming chamfers at the circumferential ends of the segments thus formed,

[0070] e) Repeating steps a) to d) until a plurality of consecutive angular segments of abradable layer are formed and cover the entire inner surface of the plate, the segments formed in step e) each comprising a circumferential end covering the chamfered circumferential end of a previously deposited segment.

[0071] The method according to the invention allows the abradable layer to be formed in a continuous plurality of segments whose edges adjacent to the circumferential ends are chamfered and overlap one another. This way of forming the abradable layer makes it possible to limit the occurrence of pores and defects in the layer.

[0072] In the specific case of its implementation, the method makes it possible to reduce the time for manufacturing the housing by 80% and, in particular, to reduce the duration for finishing the housing at the end of the method by 50%.

[0073] The method according to the present application may include one or more of the following steps or features, which may be considered independently or in combination with each other:

[0074] - the paste is based on epoxy resin and preferably is filled with, for example, glass microspheres;

[0075] - mixing is accomplished in step a) by admixing the components into a bowl of a mixer comprising at least one rotating mixing element along two non-parallel axes of rotation;

[0076] - the rotating element rotates about the axis at a speed of 400 to 1000 rpm, preferably 600 to 900 rpm, for a time of 50 to 200 seconds, preferably 80 to 120 seconds;

[0077] the dish comprises a bottom which can be withdrawn from the inside to the outside of the dish, for example by means of a piston, in order to facilitate the removal of the slurry from the dish;

[0078] - the mass of the slurry deposited in step b) is between 400 g and 2600 g;

[0079] - the housing is positioned so that the axis A is substantially horizontal during steps b) to e);

[0080] - during step c) or during each step c), the housing rotates about axis A;

[0081] - the slurry is deposited in step b) in the shape of strings or balls;

[0082] The thickness of the abradable layer is between 3 mm and 10 mm, preferably between 5 mm and 8 mm.

[0083] - the method further comprises the step i) between steps b) and c) and / or between steps c) and d): scraping the slurry or the segment by a blade;

[0084] - During step c), a plastic film is inserted between said at least one roller and said slurry;

[0085] - the at least one roller used in step c) has a non-cylindrical profiled shape;

[0086] - the guide rings in step c) are pulled axially towards each other and against the plate by means of an elastic band extending between the guide rings;

[0087] - the chamfer formed in step d) extends along the entire axial dimension of the segment and is oriented at approximately 45° to the normal to the inner surface of the segment;

[0088] - the method comprises a final step g) of conditioning the inner surface of the abradable layer, during which the shell is positioned with its axis A substantially vertical;

[0089] - The method comprises a preliminary step of bonding the plate to the inner annular surface of the cladding. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] Other features and advantages of the present invention will become apparent from the following detailed description, which will be readily understood with reference to the accompanying drawings, in which:

[0091] [ Figure 1 ] discussed above Figure 1 shows a partial cross-sectional view of a fan of an aircraft turbine according to the prior art;

[0092] [ Figure 2 ] discussed above Figure 2 shows a perspective view of a fan housing according to the prior art;

[0093] [ Figure 3 ] Figure 3 shows a schematic cross-section of a fan housing according to the prior art;

[0094] [ Figure 4 ] Figure 4 is a schematic cross-sectional view of a housing according to the prior art;

[0095] [ Figure 5 ] Figure 5 is a schematic cross-sectional view of a housing according to the present invention;

[0096] [ Figure 6 ] Figure 6 is a schematic cross-sectional view of a housing according to the prior art and illustrates the propagation of a crack;

[0097] [ Figure 7 ] Figure 7 is a schematic cross-sectional view of a housing according to the invention and illustrating the limitation of crack propagation;

[0098] [ Figure 8 ] Figure 8 For similar Figure 6 and showing an alternative or further embodiment of the present invention;

[0099] [ Figure 9 ] Figure 9 is a flow chart showing the steps of the manufacturing method according to the present invention;

[0100] [ Figure 10 ] Figure 10 is a partial schematic cross-sectional view of an aircraft turbine housing;

[0101] [ Figure 11 ] Figure 11is a schematic diagram of a component mixer for preparing a slurry;

[0102] [ Figure 12 ] Figure 12 Figures a to e are schematic diagrams of a shell and a schematic diagram of an operator spreading slurry on the shell to form an abradable layer;

[0103] [ Figure 13 ] Figure 13 is a schematic cross-sectional view of a spread abradable layer;

[0104] [ Figure 14 ] Figure 14 is a schematic diagram of an apparatus for manufacturing a turbine housing;

[0105] [ Figure 15 ] Figure 15 yes Figure 14 An enlarged schematic diagram of a portion of the device in FIG. 1 and illustrating the steps of the manufacturing method according to the present invention;

[0106] [ Figure 16 ] Figure 16 yes Figure 14 An enlarged schematic diagram of a portion of the device in FIG. 1 and illustrating further steps of the manufacturing method according to the present invention;

[0107] [ Figure 17 ] Figure 17 yes Figure 14 FIG. 2 is an enlarged schematic diagram of a portion of the device in FIG. 1 and illustrates another step in the manufacturing method according to the present invention. DETAILED DESCRIPTION

[0108] In the following description, the present invention is applied to the fan case 3. However, the present invention is not limited to this type of case and can be applied to other cases of a turbine.

[0109] The housing 3 to which the method according to the invention is applied has a substantially annular shape around an axis A. This housing 3 comprises:

[0110] an annular casing 9 extending around the axis A and made of a composite material comprising fibers woven and embedded in a resin, and

[0111] An annular layer 4 of abradable material arranged within the cladding 9 .

[0112] As mentioned above, the support plate 10 is inserted between the layer 4 and the cladding 9 and has a sandwich structure. Specifically, the support plate comprises a honeycomb layer of honeycomb type comprising open cells instead of closed cells or cells such as foam.

[0113] To avoid the problems discussed above, layer 4 may be associated with at least one fiber reinforcement, which may be of one or more types selected from, for example, fibers, fiber laps or fabrics, etc. Fabrics are formed from fibers woven together, rather than from laps of non-woven fibers.

[0114] exist Figure 5 In the example shown, reinforcing fibers 12 (eg having a length of 0.5 mm to 20 mm) are interspersed in the abradable layer 4. The reinforcing fibers include glass, aramid or carbon fibers.

[0115] exist Figure 7 In the example shown, reinforcing loops or fabrics 14 are embedded in the abradable layer 4 or are interposed between the layer 4 and the plate 10. The loops or fabrics 14 may be used in combination with the fibers 12 mixed with the abradable slurry.

[0116] In the case shown, these plates 10 are separated from one another by gaps J filled with the slurry of the layer, at least some of the rings or fabrics 14 covering these gaps. This prevents the propagation of cracks 16 appearing in these gaps J to the free surface 4b ( Figure 6 and Figure 7 ).

[0117] Figure 5 and Figure 7 The fiber reinforcement can be used alone or in combination with Figure 8 The foam layer 18 shown is used in combination. This layer 18 is inserted between the plate 10 and the wearable layer 4 and offers several advantages. In particular, it allows the thickness of the layer 4 to be reduced, thereby reducing the amount of material to be spread to make the slurry of the layer. It also reduces the risk of cracking and the problems associated with using thick layers 4.

[0118] Alternatively, according to a second embodiment of the invention, the foam layer 18 may be used without the presence of a fiber reinforcement of the abradable layer 4 .

[0119] The thickness of the foam layer 18 is, for example, between 1 mm and 7 mm, preferably between 3 mm and 5 mm. Preferably, the sum of the thicknesses of the wearable layer 4 and the foam layer 18 is less than or equal to 10 mm, and preferably less than or equal to 8 mm.

[0120] The foam layer 18 is made of thermoplastic material. The density of the foam layer can be between 20Kg / m 3 Up to 100Kg / m 3 between;

[0121] The housing according to the present invention can be manufactured as follows:

[0122] - bonding the plate 10 to the inner annular surface of the cladding 9,

[0123] - Preparing a slurry and spreading it on an inner annular surface (for example of the plate 10 ), this layer being associated with at least one fiber reinforcement.

[0124] exist Figure 5 In the embodiment shown, the reinforcing fibers 12 are mixed into the slurry before the slurry is spread.

[0125] exist Figure 7 In the embodiment shown, a reinforcing ring or fabric 14 is placed on the inner annular surface of the plate 10 prior to spreading the slurry.

[0126] Finally, in Figure 8 In the alternative or second embodiment of the invention, the slurry is spread on the inner annular surface of the foam layer 18 that has been previously bonded to the inner annular surface of the plate 10.

[0127] Figure 9 is a flow chart or block diagram illustrating the steps of a method for manufacturing an aircraft turbine casing according to the present invention.

[0128] As discussed above and as Figure 10 As shown, the housing includes:

[0129] an annular casing 9 extending around an axis A (not shown) and made of a composite material comprising fibers woven and embedded in a resin,

[0130] - an annular layer 4 of abradable material extending within the cladding, and

[0131] A support plate 10 extending around the axis A and inserted between the cladding 9 and the abradable layer 4 .

[0132] The particularity of this housing 3 is that its abradable layer 4 is formed by a plurality of angular segments 4 a which are arranged one after the other with their ends touching on the circumference (around the axis A).

[0133] Figure 9 The method according to the present invention comprises a plurality of steps, some of which are optional. Specifically, steps o), g) and i).

[0134] As will be described in more detail below and shown in the accompanying drawings, the method can be implemented manually ( Figure 12 a to e and Figure 13 ), but is advantageously achieved by at least partially automated means ( Figures 14 to 17 ).

[0135] The method may comprise a preliminary step o) of bonding the plate 10 to the inner annular surface of the cladding 3 .

[0136] The method necessarily comprises four steps a), b), c) and d), which are repeated as many times as necessary (step e)):

[0137] a) preparing a slurry 20 by mixing at least two components,

[0138] b) depositing the slurry 20 onto the inner annular surface 10d of the plate 10,

[0139] c) spreading the slurry 20 by means of at least one roller 24 extending substantially parallel to the axis A and arranged to roll on guide rings 26 arranged on either side of the plate or cladding and coaxially therewith, so as to form an angular segment 4a of the abradable layer extending over a predetermined angle about the axis A, and

[0140] d) A chamfer 28 is formed at the circumferential end of the segment 4 a thus formed.

[0141] During step e), steps a) to d) are repeated until a plurality of consecutive angular segments 4a of the abradable layer 4 are formed and cover the entire inner surface of the plate 10. The segments formed in step e) each comprise a circumferential end portion that covers the chamfered circumferential end portion of the previously deposited segment (see Figure 10 ).

[0142] Preferably, the housing 3 is positioned such that the axis A is substantially horizontal during steps b) to e).

[0143] Preferably, the slurry is based on epoxy resin and preferably, the slurry is filled with, for example, glass microspheres.The slurry is obtained by mixing at least two components.

[0144] Preferably, step a) of preparing the slurry 20 is performed by means of a mixer. It is therefore not done manually, as manual manipulations tend to cause air bubbles to appear in the slurry and, due to the viscosity of the slurry, in the abradable layer after polymerization.

[0145] Figure 11 Such a mixer is shown in a schematic manner. In step a), the components are admixed into a bowl 40 of a mixer, said bowl comprising at least one rotating mixing element 42 along two non-parallel axes of rotation Y and Y.

[0146] For example, the mixer is a FlackTek DAC3000.

[0147] The rotating element 42 of the mixer rotates about the axis X, Y at a speed of 400 to 1000 rpm (preferably 600 to 900 rpm) for a time of 50 to 200 seconds (preferably 80 to 120 seconds).

[0148] Preferably, the dish 40 in which the slurry is mixed has a bottom 40a that can be removed and withdrawn by axial translation from the inside to the outside of the dish. For example, the displacement (see arrow 44) can be accomplished by a piston resting on the lower surface of the bottom 40a. When the bottom 40a is removed from the dish 40, the upper surface of the bottom can be scraped to remove all the slurry and facilitate the arrangement of the slurry in the next step.

[0149] The mass of the slurry deposited in step b) and used to form the segments may be between 400 g and 2600 g.

[0150] Figure 12 Figures a to e show the steps of the manual method. Figure 12 FIG. 1 a shows step b) of depositing the slurry 20 in the shape of balls or strings on the inner annular surface 10 d of the plate 10 .

[0151] Figure 12 b and Figure 12 c in FIG shows step c): firstly, the slurry 20 is spread on the surface 10d by a roller 22 capable of distributing the slurry ( Figure 12 b), the slurry is then spread a second time by a shaping roller 24 (the shaping roller can be placed on the guide ring 26) so that the slurry has a corrected thickness so that the thickness of the slurry is uniform ( Figure 12 c) in the above example.

[0152] The slurry 20 is then extended over a predetermined angular section of the surface 10d and, in step d), a chamfer 28 is produced at the circumferential edge of said slurry so that, during step e), the slurry deposited and spread over the adjacent angular section can cover the chamfered edge ( Figure 12 d, e and Figure 13 ).

[0153] Figure 14 The following figures show the steps of the method performed by an automated device.

[0154] Figure 14 The device 50 in particular comprises:

[0155] - means 52 for rotating the housing 3 about the axis A during step c) or each step c),

[0156] - a device 54 for preparing a slurry 20 based on the mixture described above,

[0157] - a device 56 for depositing the slurry 20 in the shape of balls or strings on the inner surface of the plate 10,

[0158] - an optional device 58 for scraping the slurry 20 and preforming it before spreading,

[0159] - a device 60 for spreading the slurry using rollers 24 to form each section 4a of the abradable layer,

[0160] an optional device 62 for unrolling a plastic film 62 and inserting this plastic film 20 between the slurry and the spreading rollers 24 of the device 60 ,

[0161] - an optional device 64 for scraping the inner surface of each segment 4a after spreading, and

[0162] A device 66 for cutting the circumferential end of each segment to form the chamfer 28 .

[0163] The device 52 may comprise an electric motor connected to a drive wheel about the axis A of the housing 3 via a sprocket.

[0164] Preferably, the device 54 includes the above combined Figure 11 A mixer 40 of the type described. Figure 14 As shown, the mixer is connected via a pump 54a to a reservoir 54b for storing the components to be mixed to form the slurry.

[0165] The device 56 comprises a head for depositing the slurry, movable along one or more axes so as to optimize the deposition of the slurry on the inner surface of the plate 10 .

[0166] Figure 15 The illustrated apparatus 58 includes at least one blade 58 a for contacting the ball or string-shaped slurry 20 to squeeze the slurry and force it to be applied and spread on the plate, and to pre-shape the slurry to facilitate spreading the slurry through the roller 24 .

[0167] Spreading roller 24 Figure 16 1 and comprises, for example, a first coating roller 24a, a second preforming roller 24b and a third finishing roller 24c. As mentioned above, these rollers 24 roll on guide rings 26 mounted on each side of the plate 10.

[0168] As shown in the figures, the roller 24 is preferably profiled and non-cylindrical so as to give the inner surface of the segment 4a a Figure 1 The desired non-cylindrical shape is shown.

[0169] Roller 24 is made of plastic material, for example. Roller 24a enables to obtain a slurry thickness that is 1 mm greater than the final desired measurement value. Roller 24b enables to obtain a slurry thickness that is 0.5 mm greater than the final desired measurement value. Roller 24c enables to obtain a slurry thickness that is the desired final measurement value.

[0170] Preferably, the guide rings 26 are pulled axially toward each other and against the plate 10 by elastic bands 65 extending between the guide rings 26. In a particular example, the guide rings 26 on each side of the housing 3 include a first ring 26a for rolling the roller 24 and a second ring 26b for holding the first ring 26a, the first ring having an inner diameter D1 and the second ring having an inner diameter D2, D2 being greater than D1.

[0171] The second loop 26 b rests on the first loop 26 a, the first loop being interposed between the second loop and the plate 10. The second loop 26 b carries a hook 66 for attaching a first end of an elastic band 65, the opposite end of which is attached to a hook 66 carried by the second loop 26 b situated on the opposite side of the housing 3. The second loops 26 b are thus pulled axially towards each other by these tensile stretching elastic bands 65 and thus axially retain the first loop 26 a on both sides of the plate 10.

[0172] The rings 26a and 26b are made of carbon fibers, for example.

[0173] Figure 17 The purpose of the device 62 shown is to insert a plastic film 62 between the slurry 20 and the roller 24 , which prevents direct contact and the risk of adhesion between the slurry and the spreading roller 24 .

[0174] Roller 24a can then be used to ensure the positioning of the film and to press the film onto the slurry. Roller 24b can ensure the deformation of the film and to shape the slurry.

[0175] Device 64 is similar to Figure 15 The device may include at least one blade 58a for coming into contact with the already formed segment 4a in order to perfect the surface condition of the inner surface of the segment.

[0176] exist Figure 16 The apparatus 68 visible in the figure may comprise cutting rollers or discs 70 for separating the layers 4 from each side of the plate 10 and facilitating demoulding after polymerization. They may also be used to cut the circumferential ends of each segment 4a in order to form Figure 13 The chamfer 28 is visible in FIG. 1 (when this cut is not made manually).

[0177] The thickness of the abradable layer 4 is between 3 and 10 mm, preferably between 5 and 8 mm. The chamfer 28 formed in step d) extends over the entire axial dimension of the segment 4a and is oriented at approximately 45° to the normal to the inner surface of the segment.

[0178] In the next step f), the slurry is polymerized. This can be done at room temperature or in an oven.

[0179] Finally, the method may comprise a final step g) of conditioning the inner surface of the abradable layer 4 , during which the shell 3 is positioned with its axis A substantially vertical.

Claims

1. A method of manufacturing an aircraft turbine housing (3), the housing comprising: an annular casing (9) extending around the axis A and made of a composite material comprising fibers woven and embedded in a resin, - an annular layer (4) of abradable material extending within said cladding, and - a support plate (10) extending around the axis A and interposed between the cladding and the annular layer of abradable material, characterized in that the method comprises the following steps: a) preparing a slurry (20) by mixing at least two components, b) depositing said slurry onto the inner annular surface (10d) of the plate, c) spreading the slurry by means of at least one roller (24) extending substantially parallel to the axis A and arranged to roll on guide rings (26) arranged on either side of the plate or cladding and coaxial with said guide rings, so as to form angular segments (4a) of annular layers of abradable material, said angular segments extending over a predetermined angle around said axis A, d) forming chamfers (28) at the circumferential ends of the angled sections thus formed, e) repeating steps a) to d) until a plurality of consecutive angular segments (4a) of the annular layer (4) of abradable material are formed and cover the entire inner annular surface (10d) of the plate (10), the angular segments formed in step e) each comprising a circumferential end covering the chamfered circumferential end of a previously deposited angular segment.

2. The method according to claim 1, wherein The slurry (20) is based on epoxy resin.

3. The method according to claim 1 or 2, wherein: Mixing is accomplished in step a) by admixing the components into a bowl (40) of a mixer comprising at least one rotating mixing element (42) along two non-parallel axes of rotation (X, Y).

4. The method according to claim 3, wherein: The rotating mixing element (42) rotates about the axis at a speed of 4400 to 1000 rpm for a period of 50 to 200 seconds.

5. The method according to claim 4, wherein The dish (40) includes a bottom (40a) that can be withdrawn from the inside to the outside of the dish to facilitate removal of the slurry (20) from the dish.

6. The method according to claim 1 or 2, wherein: The mass of the slurry (20) deposited in step b) is between 400 g and 2600 g.

7. The method according to claim 1 or 2, wherein: The housing (3) is positioned such that the axis A is substantially horizontal during steps b) to e).

8. The method according to claim 7, wherein: During step c), said housing ( 3 ) rotates about said axis A.

9. The method according to claim 1 or 2, wherein: The slurry (20) is deposited in the shape of strings or balls in step b).

10. The method according to claim 1 or 2, wherein: The thickness of the annular layer (4) of abradable material is between 3 mm and 10 mm.

11. The method according to claim 1 or 2, wherein: The method further comprises the step i) between steps b) and c) and / or between steps c) and d): scraping the slurry (20) or the angled segment by a blade (58a).

12. The method according to claim 1 or 2, wherein: During step c), a plastic film (62) is inserted between said at least one roller (24) and said slurry (20).

13. The method according to claim 1 or 2, wherein: The at least one roller (24) used in step c) has a non-cylindrical profiled shape.

14. The method according to claim 1 or 2, wherein: The guide rings (26) in step c) are pulled axially towards each other and against the plate (10) by means of an elastic band (65) extending between the guide rings (26).

15. The method according to claim 1 or 2, wherein: The chamfer (28) formed in step d) extends along the entire axial dimension of the angular segment and is oriented at approximately 45° to the normal to the inner surface of the angular segment.

16. The method according to claim 2, wherein: The slurry is filled with glass microspheres.

17. The method according to claim 3, wherein: The rotating mixing element (42) rotates about the axis at a speed of 4400 to 1000 rpm for a period of 80 to 120 seconds.

18. The method according to claim 3, wherein The rotating mixing element (42) rotates about the axis at a speed of 600 to 900 rpm for a time of 50 to 200 seconds.

19. The method according to claim 3, wherein: The rotating mixing element (42) rotates about the axis at a speed of 600 to 900 rpm for a period of 80 to 120 seconds.

20. The method according to claim 5, wherein The bottom portion can be withdrawn from the inside to the outside of the dish by means of a piston.

21. The method according to claim 10, wherein The thickness of the annular layer (4) of abradable material is between 5 mm and 8 mm.

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