AIRCRAFT TURBOMACHINE EQUIPPED WITH AN ELECTRIC ENGINE

Abstract

An aircraft turbomachine (10) comprising: - an annular ventilation air circulation enclosure (Z), this enclosure extending around a principal axis (A) of the turbomachine and comprising at least one air inlet (80) and at least one air outlet (82, 83), - an annular electrical machine (70) extending around the principal axis (A) of the turbomachine, inside the enclosure (Z), and comprising a coaxial rotor (70a) and stator (70b) which define between them an annular air gap (84) for the passage of a first ventilation airflow (F2), characterized in that it further comprises a magnetic trap (100) for metallic particles, this trap being located in said enclosure (Z) and being configured to attract and retain the metallic particles contained in said first airflow (F2). Figure for the abbreviation: Figure 5

Description

Title of the invention: AIRCRAFT TURBOMACHINE EQUIPPED WITH AN ELECTRIC MACHINE Technical field of the invention

[0001] The present invention relates to an aircraft turbomachine equipped with an electric machine, as well as a method for maintaining this turbomachine. Technical background

[0002] The state of the art includes in particular documents FR-A1-2 842 565, FR-Al-2 896 537 and FR-A1-2 922 265 which describe turbomachines equipped with electric machines.

[0003] The aeronautical world is currently asking itself many questions regarding the relevance of using hybrid engines for commercial aviation. The use of electrical energy is now being considered not only to fulfill aircraft functions but also to electrify turbomachine functions.

[0004] This observation leads to the study of hybrid engine architecture solutions, combining the fossil energy of the fuel and the electrical energy to ensure the drive of the propulsion part (turbomachine fan) and the supply of certain engine and / or aircraft functions.

[0005] It is known to equip an aircraft turbomachine with an electric machine. An electric machine is an electromechanical device based on electromagnetism that allows the conversion of electrical energy, for example, into work or mechanical energy. This process is reversible and can be used to produce electricity.

[0006] Thus, depending on the end use of a machine, the following terms are used: - generator to designate an electrical machine that produces electrical energy from mechanical energy, - motor for an electrical machine producing mechanical energy from electrical energy.

[0007] An electrical machine can also behave in motor mode as well as in generator mode.

[0008] Integrating an electric machine into a turbomachine is relatively complex. Several installation areas are possible, but the advantages and disadvantages of each are numerous and varied (problems of mechanical integration of the machine, temperature resistance of the machine, accessibility of the machine, etc.).

[0009] An electrical machine classically comprises a rotor and a stator. The De- Manderesse has already proposed integrating an annular-shaped electrical machine directly downstream of a turbomachine blower. This electrical machine is located in an annular enclosure through which a ventilation airflow circulates during operation.

[0010] This air is generally drawn from the engine or gas generator of the turbomachine and circulates through seals, passing near roller bearings. These bearings are subject to wear and generate metallic dust, some of which can contaminate the ventilation air. The ventilation air circulating within the housing of the electric machine may therefore contain metallic particles.

[0011] The rotor and stator of the electric machine are separated by an annular air gap through which ventilation air can circulate. Metallic particles contained in this air are then likely to be attracted and retained by the permanent magnets of the stator or rotor and to accumulate in this air gap. This air gap must have a precise dimension, and this phenomenon risks causing a change in this dimension or even a filling of the air gap, which is very problematic.

[0012] Furthermore, another problem with this type of electrical machine is its maintenance and access in a restricted environment.

[0013] The present invention proposes a solution to at least some of the problems mentioned above. Summary of the invention

[0014] The invention proposes an aircraft turbomachine, comprising: - an annular air circulation chamber for ventilation, this chamber extending around a main axis of the turbomachine and comprising at least one air inlet and at least one air outlet, - an annular electrical machine extending around the main axis of the turbomachine, inside the enclosure, and comprising a coaxial rotor and stator which define between them an annular air gap for the passage of a first ventilation airflow, characterized in that it further comprises a magnetic trap for metallic particles, this trap being located in said enclosure and being configured to attract and retain the metallic particles contained in said first airflow.

[0015] The invention thus proposes to attract and trap the magnetic particles contained in the first airflow in order to prevent this airflow from being contaminated with these particles. The airflow passing through the air gap of the electric machine is therefore free of magnetic particles, which limits the risk of particle deposition and amalgamation in this area. The invention is particularly advantageous insofar as the The trap operates autonomously and continuously, as it does not require monitoring and functions constantly. Depending on the amount of magnetic particles in the airflow deposited on the trap, it may require maintenance, during which it is cleaned, or disassembled and replaced. This maintenance can be performed at regular intervals, for example, during turbomachine maintenance.

[0016] The turbomachine according to the invention may comprise one or more of the following features, taken individually or in combination with each other:

[0017] - the particle trap comprises a ring of magnets extending around the axis main part of the turbomachine;

[0018] - the ring of magnets is located on a circumference whose diameter D is between Dmin and Dmax, which are respectively the minimum diameter and the maximum diameter of the electrical machine;

[0019] - the ring of magnets comprises a support ring and a plurality of magnets regularly distributed on the support ring and around the main axis;

[0020] - the ring of magnets is fixed to a wall of the enclosure by means of fixing removable;

[0021] - the stator of the electric machine is supported by a first annular element of support, one end of which is fixed to the said wall of the enclosure, and surrounds the said ring of magnets;

[0022] - the first element comprises, upstream of the ring of magnets, openings forming said at least one air outlet;

[0023] - the rotor of the electric machine is supported by a second annular element of support which includes a cylindrical wall surrounded by the rotor and fixed to the inner periphery of the latter;

[0024] - this cylindrical wall comprises, on the side opposite the ring of magnets, through-holes for the passage of a second ventilation airflow;

[0025] - said at least one air inlet is located on an internal periphery of the enclosure, and said at least one air outlet is located on an external periphery of the enclosure;

[0026] - the second annular support element comprises a radial annular wall of which the outer periphery is connected to said cylindrical wall and the inner periphery is connected to drive shaft;

[0027] - the radial annular wall has through-holes for the passage of a second ventilation airflow;

[0028] - the first support element comprises first annular extensions which extend axially upstream and second annular extensions that extend axially downstream, the radial annular wall of the second element of support comprising annular third extensions which extend axially upstream, with dynamic sealing joints provided between the second extensions and the third extensions;

[0029] - the radial annular wall and the drive shaft to which it is connected both limit a part of said enclosure, with dynamic sealing joints being provided between the first extensions and this drive shaft;

[0030] - the electric machine is mounted downstream of a blower configured to rotate around said main axis, the rotor of the electric machine being rotationally fixed to the blower; and / or the electric machine is mounted inside an exhaust cone of the turbomachine, the rotor of the electric machine being rotationally fixed to a drive shaft of the turbomachine extending into this exhaust cone;

[0031] - the enclosure is located just downstream of the blower, said at least one air inlet being formed by a dynamic sealing joint mounted between an annular bearing support and a blower drive shaft, and said at least one air outlet being located in a flow channel of an airflow exiting the blower; and / or the enclosure is located inside the exhaust cone, said at least one air inlet being formed by at least one dynamic seal provided between the first support element and the drive shaft, and / or an opening formed in the drive shaft, and said at least one air outlet being located in a flow channel of an airflow exiting the exhaust cone.

[0032] The present invention further relates to a method of maintenance of a turbomachine as described above, comprising a step in which the particle trap is disassembled, then cleaned and reassembled, or replaced with a new one. Brief description of the figures

[0033] The invention will be better understood and other details, features and advantages of the invention will become apparent upon reading the following description, given by way of non-limiting example with reference to the accompanying drawings, in which:

[0034] [Fig.1] is a schematic axial cross-sectional view of an aircraft turbomachine;

[0035] [Fig. 2] is a partial schematic axial cross-sectional half view of a turbomachine aircraft equipped with an electric machine;

[0036] [Fig.3] is a larger scale view of part of [Fig.2];

[0037] [Fig.4] is a larger scale view of a detail I4 of [Fig.3];

[0038] [Fig. 5] is a partial schematic half-view in axial section of a turbomachine aircraft equipped with an electric machine according to a first aspect of the invention;

[0039] [Fig.6] is a very schematic partial view of the magnet ring of the turbomachine of [Fig.5];

[0040] [Fig.7] is a partial schematic half axial cross-sectional view of an aircraft turbomachine equipped with an electric machine;

[0041] [Fig.8] is a larger scale view of part of [Fig.7];

[0042] [Fig. 9] is a partial schematic half-view in axial section of a turbomachine aircraft equipped with an electric machine according to a second aspect of the invention; and

[0043] the [Fig. 10] is a partial schematic half view of an alternative embodiment of the electric machine of the [Fig.9].

[0044] Elements having the same functions in the different implementations have the same references in the figures. Detailed description of the invention

[0045] Reference is made first to [Fig. 1] which schematically represents a twin-body, twin-flow aircraft turbomachine 10.

[0046] The turbomachine 10 conventionally comprises a gas generator 12 upstream of which is arranged a blower 14. The blower 14 is surrounded by a casing 16 which is surrounded by a nacelle 18 which extends around and along a major part of the gas generator 12.

[0047] The gas generator 12 here comprises two bodies, namely a low-pressure body 12a or BP and a high-pressure body 12b or HP. Each body comprises a compressor and a turbine.

[0048] The terms "upstream" and "downstream" are considered according to a main direction F of gas flow in the turbomachine 10, this direction F being parallel to the longitudinal axis A of the turbomachine.

[0049] From upstream to downstream, the gas generator 12 comprises a low pressure compressor 20, a high pressure compressor 22, a combustion chamber 24, a high pressure turbine 26 and a low pressure turbine 28.

[0050] The fan 14 comprises an annular row of blades 30 driven in rotation by a fan shaft 32 which is connected to the rotor of the low-pressure body 12a via a reduction gear 33. The gas flow through the fan (arrow F) is separated upstream of the gas generator 12 by an annular nozzle 34 into an internal radially annular flow, called the primary flow 36 which flows into a primary annular channel of the gas generator 12, and into an external radially annular flow, called the secondary flow 38 which flows into a secondary annular channel between the gas generator 12 and the nacelle 18 and provides most of the thrust of the turbomachine.

[0051] An inlet housing 40 structurally connects the gas generator 12 to the housing 16 and the nacelle 18. The inlet housing 40 comprises an annular row of radially internal arms 42 extending into the primary flow channel 36, and a annular row of straightening blades 44, called OGV (acronym for Outer Guide Varie), radially external extending in the secondary flow vein 38.

[0052] The arms 42 are generally limited in number (less than ten) and are tubular and traversed by servitudes.

[0053] These arms 42 have a structural role as they allow the transmission of forces between the bearing supports and the suspensions. They also serve as conduits for the service lines, allowing them to pass through the flow channel while being enclosed, thus limiting aerodynamic losses within the channel. These arms do not have a flow straightening function because they lack curvature and are not numerous enough to perform this function.

[0054] The number of straightening blades 44 (OGV) is generally greater than ten. They straighten the blower flow thanks to a specific number and camber. They also have a structural function as they support the housing around the blower (blower housing).

[0055] The primary flow channel 36 is further traversed by straightening blades 52, called IGVs (acronym for File Guide Varie). The IGVs 52 are regularly distributed around axis A and are located upstream of the inlet casing 40, and more precisely upstream of the arms 42. These blades straighten the flow from the blower as it enters the primary channel. They have no structural role. They are present in sufficient number (for example, more than 10) and with a certain camber to straighten the flow from the blower entering the primary channel.

[0056] The primary flow channel 36 is delimited by two coaxial annular sheaths, respectively inner 37a and outer 37b. The IGVs 52 and the arms 42, in particular, are connected to these sheaths 37a, 37b. The secondary flow channel 38 is delimited internally by an annular sheath 39 coaxial with the sheaths 37a, 37b, and externally by the nacelle housing 16. The OGVs 44 are connected to the sheaths 37b, 39.

[0057] Each of the envelopes 37a, 37b, 39 can be formed by several adjacent walls or hoods.

[0058] The rotor of the low-pressure body 12a and the blower shaft 32 are guided upstream by bearings 46, 48 and 50. These bearings 46, 48, 50 are of the ball or roller type and each comprise an inner ring mounted on the shaft to be guided, an outer ring carried by an annular bearing support and a bearing between the rings.

[0059] As is known, the reducer 33 is of the epicyclic gear train type and comprises a sun gear centered on the axis A, a crown extending around the axis, and satellites which they mesh with the solar system and the corona and are carried by a satellite carrier.

[0060] In the example shown, the ring is fixed and fixedly connected to a support 62 of the bearings 46, 48. The planet carrier is rotating and coupled by the blower shaft 32. The solar element of the reducer is coupled by an input shaft 56 to a main drive shaft 58 of the low pressure body.

[0061] The input shaft 56 is guided by the bearing 50 which is carried by a bearing support 60. The blower shaft 32 is guided by the bearings 46, 48.

[0062] The bearing supports 60, 62 extend around the axis A and are fixed parts connected to the stator and in particular to the input housing 40.

[0063] The turbomachine 10 may include an exhaust cone 29 that may extend the turbomachine 10 downstream. This cone 29 is centered on axis A and has a tip or end of smaller diameter oriented downstream. An annular primary cowl 27 may coaxially surround the cone 29 to define with it an annular channel for the passage of the primary air flow F. The cone 29 and the primary cowl 27 may form an exhaust nozzle 25 of the turbomachine 10. The cone 29 allows the combustion gases generated by the gas generator 12 to be discharged. In the example of [Fig. 1], the cone 29 is located downstream of the low-pressure turbine 28.

[0064] [Fig.2] is a more detailed and larger-scale view of part of [Fig.1], and illustrates a turbomachine 10 equipped with an electric machine 70 according to a first aspect of the invention.

[0065] The elements of [Fig.2] which have already been described with reference to [Fig.1] are designated by the same references.

[0066] Fig. 2 shows in particular the installation area of ​​the electric machine 70, this area being located between the blower disc 32a, connecting the blower blades 30 to the blower shaft 32, and the reducer 33. Only a support 33a of the ring gear of the reducer 33 is visible in Fig. 2, this element being for example connected to the input housing 40 or to the bearing support 62.

[0067] The cross-section of the drawing in [Fig. 2] passes through one of the IGV 52, which may be solid. At least one or some of the IGV 52 may be tubular. The cross-section passes through an OGV 44 and also through an arm 42, which is tubular for the passage of service lines, as mentioned above. The tubular IGV 52 and / or the tubular arm 42 could be traversed by electrical connection means for the electric machine 70.

[0068] The reducer 33 and the bearings 46, 48, 50 visible in [Fig.1] are located in an annular lubrication enclosure E which is closed upstream by the bearing support 62 and by at least one seal not visible in [Fig.2], and downstream by the bearing support 60 and by at least one seal not visible in [Fig.2].

[0069] The electrical machine 70 is located in an annular ventilation enclosure Z, referred to as the first enclosure Z, which is delimited upstream by the blower 14, and in particular the disc 32a, and downstream by the bearing support 62 and at least one seal not visible in [Fig.2].

[0070] The machine 70, more clearly visible in [Fig.3], has a general annular shape and comprises a rotor 70a and a stator 70b. The rotor 70a has a general annular shape extending around the axis A and is supported by a second support element 72 which itself has a general annular shape.

[0071] In the example shown, the second support element 72 comprises a cylindrical wall 72a surrounded by the rotor 70a and fixed to the inner periphery of the latter. The upstream end of this wall 72a is connected on one side to a radially internal annular flange 72b for fixing to the blower disc 32a, and on the other side to an external annular rim 72c.

[0072] The rim 72c includes an internal cylindrical surface 72d bearing against an external cylindrical surface of the blower 14 in order to ensure the centering of the rotor 70a. The rim 72c further includes external annular flaps 72e of a labyrinth-type sealing gasket.

[0073] The stator 70b also has a general annular shape and is supported by a first annular support element 74 formed by the assembly of two coaxial annular parts: - an annular support 75a which surrounds and covers at least part of the stator 70b and which is fixed to the outer periphery of the stator, and - an annular hood 75b which surrounds and covers at least part of the support 75a.

[0074] The hood 75b includes a surface 74a which internally defines the flow path of the gas flow F, between the blower 14 and the separation nozzle 34. This surface 74a is thus swept by the gas flow F.

[0075] The electric machine 70, and in particular its stator 70b, is thus located as close as possible to the main flow F after passing through the blower 14. This allows, on the one hand, for an electric machine 70 with a large diameter and therefore with a relatively high potential power, and a machine which is cooled by the flow F. Advantageously, the thermal rejections of the electric machine M are dissipated thanks to this cooling.

[0076] For this purpose, the surface 74a swept by the flow F preferably has an aerodynamic profile, as shown in the drawing. The first element 74 ensures the exchange of heat by thermal conduction between the stator 70b and the flow F.

[0077] The hood 75b includes at its upstream end an internal cylindrical surface 75ba which is for example coated with an abradable layer, and which cooperates with the aforementioned lugs 72e to form the labyrinth seal.

[0078] The downstream end of the hood 75b is axially aligned with a ferrule 64 connected to the inner periphery of the IGV 52 and of which an upstream peripheral edge 64a is engaged axially in an annular groove 74b of the cap 75b. This groove 74b is oriented axially downstream. The engagement of the upstream edge 64a of the ferrule 64 in the groove 74b ensures an overlap and thus prevents a step in the vein that would disrupt the flow F.

[0079] In the vicinity of its downstream end, the hood 75b includes screw mounting holes 75bb. The holes 75bb are oriented substantially radially with respect to the axis A and are preferably regularly distributed around this axis.

[0080] The cover 75b further comprises an internal cylindrical mounting surface 75bc fitted onto an external cylindrical surface 75aa of the support 75a. The cover 75b is intended to be mounted on the support 75a by axial translation and sliding of the cover on the support, and more particularly of the surfaces 75bc, 75aa one on the other.

[0081] The support 75a includes a cylindrical wall 75ab connected at its downstream end to an annular flange 76 for fixing to the bearing support 62 and the inlet housing 40.

[0082] The wall 75ab includes at its downstream end blind holes 75ac which are tapped and which are aligned with the orifices 75bb for the passage and screwing of the screws 77.

[0083] The flange 76 has a general U-shaped axial cross-section with its opening oriented radially outwards. In the example shown, the flange 76 is fixed by screws to a flange of the bearing support 62 and to a flange 40b of the inlet housing 40.

[0084] The flange 76 thus defines an annular space X which serves for the electrical connection of the stator 70b. The space X is delimited externally by the ferrule 64. It is therefore understood that in the absence or dismantling of this ferrule 64, the space X can be accessed.

[0085] The stator 70b is connected by electrical connection means to a power electronic circuit 78 which is located between the two envelopes 37b, 39 and therefore in the gas generator 12 ([Fig.2]).

[0086] The means for electrically connecting the stator 70b to the circuit 78 may include harnesses and one or more rigid electroconductive bars.

[0087] Fig. 3 shows that the IGV 52 here form a monobloc annular assembly with coaxial annular ferrules 64, 66 and 68.

[0088] The ferrule 64 is thus integral with the radially internal ends of the IGV 52. Its upstream end includes the edge 64a engaged in the groove 74b, and its downstream end includes an edge 64b in axial support against a cylindrical shoulder of the inlet housing 40.

[0089] The ferrule 66 extends around the ferrule 64 and is integral with the radially external ends of the IGV 52. Its upstream end is connected to the upstream end of the ferrule 68 to form the separating beak 34. The ferrule 68 extends around the ferrule 66. The downstream ends of the ferrules 66, 68 are also connected together to form an annular flange 79 for fixing by screws or the like to the inlet housing 40.

[0090] As mentioned above, the first enclosure Z is a ventilation enclosure, meaning that at least one airflow circulates within this first enclosure Z from at least one air inlet to at least one air outlet. In the example shown, an air inlet 80 is located on the inner periphery of the first enclosure Z and is formed by at least one sealing gasket (arrow Fl) located at the bearing 46. An air outlet 82 is located on the outer periphery of the first enclosure Z and is formed by the sealing gasket formed by the interaction of the flaps 72e with the surface 75ba (arrow F3). The airflow which enters the first enclosure Z through the inlet 80 flows from the inner periphery to the outer periphery, and joins the outlet 82 by passing through the air gap 84 of the electric machine 70, that is to say the gap between the rotor 70a and the stator 70b of the electric machine 70 (arrow F2).

[0091] The path of this ventilation airflow, before reaching the inlet 80, is described below with reference to [Fig.4] which illustrates in more detail detail L of [Fig.3] in which the landing 46 is located.

[0092] Reference numeral 62 in [Fig. 4] also designates the bearing support and shows that this bearing support includes integrated ventilation air passages 62a. This air comes, for example, from the low-pressure compressor 20 or the high-pressure compressor 22 of the turbomachine 10 and is drawn from this compressor by suitable means, and reaches the passages 62a. In the example shown, the bearing support 62 has a generally frustoconical shape flared downstream, and the passages 62a follow this shape from upstream to downstream, so that they are inclined radially outwards from upstream to downstream. Several passages 62a can be integrated into the bearing support 62, and only one of these passages is visible in the drawing. The air circulating in the pipes 62a flows from downstream to upstream, radially towards the inside (arrow F4 in the [Fig.4]) and arrives in an annular space R located between a labyrinth seal 86, situated upstream, and an assembly comprising another seal 88 of the JRS type (acronym for segmented radial seal) and an oil-sealing auger 90, this assembly being located downstream. The oil-sealing auger 90 is thus located on the side of the enclosure E and limits the direct contact of the oil from this enclosure with the seal 88.

[0093] The seals 86, 88 and the auger 90 are mounted between the inner periphery of the bearing support 62 on the one hand, and an annular member 92 mounted on the blower shaft 32 on the other. This member 92 is rotationally fixed to the shaft 32 and bears axially on the inner ring 46a of the bearing 46 in the example shown. This member 92 comprises a cylindrical rim 92a upstream which carries annular lugs of the seal 86 designed to cooperate with an abradable coating of the support 62, and an external radial rim 92b downstream which is located downstream of the seal 88 and the auger 90. The outer periphery of this external radial rim is configured to promote the formation and the projection of oil droplets during operation thanks to centrifugal forces.

[0094] Fig. 4 shows that part of the air exiting the pipes 62a flows through the joint 86 to form the aforementioned airflow Fl, and that another part flows through orifices 94 of the organ 92 to form another airflow F5 for pressurizing the aforementioned enclosure E in which the bearing 46 is located.

[0095] The sealing gasket 88 must be under positive pressure outside the enclosure E relative to the inside of the enclosure E, so that an airflow passes through it from the outside to the inside, thus preventing oil from flowing in the opposite direction. This air supply is provided by the pipe 62a, which is attached to the stator. Therefore, leaks can occur between the stator and the rotor, and these leaks constitute the air supply. These leaks are limited by the gasket 86, but some still remain, and it is these residual leaks that constitute the air supply via the air inlet 80.

[0096] The airflow Fl is likely to contain suspended metallic particles, for example generated by wear of the turbomachine bearings. When the airflow F2 passes through the air gap 84, these particles are likely to be deposited on the permanent magnets of the rotor 70a (in the example shown) or the stator 70b of the electric machine 70, and to modify the dimensions of this air gap 84.

[0097] The present invention proposes a solution to this problem, a preferred embodiment of which is shown in Figures 5 and 6. It proposes to install a magnetic trap 100 for metallic particles in the first enclosure Z, this trap 10 being configured to attract and retain the metallic particles contained in the airflow F2 before its passage through the air gap 84.

[0098] Figures 5 and 6 illustrate a non-limiting example of positioning and realization of the particle trap 100.

[0099] The particle trap 100 includes a ring of magnets 102 extending around the axis A. The ring of magnets 102 is located on a circumference C whose diameter D is between Dmin and Dmax, which are respectively the minimum diameter and the maximum diameter of the electrical machine 70.

[0100] As can be seen more clearly in [Fig.6], the ring of magnets 102 comprises a support ring 104 and a plurality of magnets 106 regularly distributed on the support ring 104 and around the axis A. The magnets 106 can be fixed to the support ring 104 by gluing, for example.

[0101] The ring of magnets 102 is fixed to a wall of the first enclosure Z, which is the bearing support 62 in the example shown. The fixing is, for example, achieved by screws or rivets that pass through openings 108 in the support ring 104 and aligned openings or blind holes in the bearing support 62. The support ring 104 preferably has an annular surface that complements (for example, frustoconical and smooth) that of the wall to which it is applied and fixed. The openings 108 are also of The magnets are preferably evenly distributed between the magnets 106, with each orifice 108, for example, located between two adjacent magnets 106. The screws, for example, have their heads located in the first enclosure Z and are preferably flat or configured to limit pressure losses and turbulence in this area.

[0102] In the example shown, the trap 100 is located on the outer periphery of the first enclosure Z, just inside the flange 76. The flange 76 thus surrounds the trap 100, and the airflow F2, which flows from the inner periphery of the first enclosure Z to its outer periphery along the bearing support 62, is deflected by the flange 76 before entering and flowing into the air gap 84. The trap 100 is located at this deflection. The trap 100 is thus positioned to attract and retain, by magnetism, the metallic particles contained in the airflow F2.

[0103] Advantageously, another airflow F6 is provided to bypass the air gap 84 and directly reach the outlet 82 of the first enclosure Z. For this purpose, the cylindrical wall 72a of the second support element 72 has, on the side opposite the ring of magnets 102, through-holes 110 for the passage of this other ventilation airflow F6. These holes 110 are preferably regularly distributed around the axis A. They are preferably arranged in pairs, the holes of each pair being diametrically opposite with respect to the axis A. This limits the risk of an imbalance occurring in the blower 14, due to the presence of these holes 110.

[0104] Preferably, the flow rate of the airflow F6 is greater than the flow rate of the airflow F2.

[0105] Advantageously, one or more endoscopy holes 112 could be provided to inspect the loading of the magnets 106. For example, radial holes 112 traversing the X space.

[0106] [Fig.7] is a more detailed and larger-scale view of another part of [Fig.1], and illustrates the turbomachine 10 equipped with an electric machine 70 according to a second aspect of the invention.

[0107] The elements of [Fig.7] which have already been described with reference to Figures 1 to 5 are designated by the same references.

[0108] Figure 7 shows in particular another installation area for the electric machine 70 according to the second aspect of the invention. This area is located inside the cone 29, and therefore downstream of the low-pressure turbine 28. As is known, the low-pressure turbine 28 may include rotor blades 27 and nozzle distributor blades.

[0109] In the example of Figures 1 and 7, the cone 29 also extends around the axis A. The main drive shaft 58 can extend to the cone 29. This shaft 58 can be guided downstream by bearings 47 and 49. These bearings 47, 49 can be of the ball or roller type and can each comprise an inner ring mounted on the shaft to be guided, an outer ring carried by an annular bearing support and a bearing between the rings.

[0110] These bearings 47, 49 are located inside an annular enclosure G forming a pressurization chamber (hereinafter referred to as the pressurization chamber). The electrical machine 70 is located downstream of this pressurization chamber G.

[0111] The pressurization chamber G can be inside the annular ventilation chamber Z, called the second chamber Z, of the cone 29. In the example of [Fig.7], the second chamber Z can be delimited upstream by a hood 290 which can form a wall of the second chamber Z, and downstream by a housing 292 of the cone 29. The electrical machine 70 is located in this second chamber Z.

[0112] Pressurized air enters the pressurization chamber G, as schematically shown by arrows Fl, F10. For example, air is taken from the inlet of the high-pressure compressor 22 and distributed to the pressurization chamber G and the second chamber Z via shaft 58 (arrow Fl). The pressurization chamber G and the second chamber Z can be supplied with air by the low-pressure turbine 28 (arrow F10).

[0113] Fig. 8 is an enlarged view of the second enclosure and the electrical machine 70.

[0114] The machine 70 can also have a general annular shape and can understand a 70a rotor and a 70b stator.

[0115] The stator 70b may also have a generally annular shape and may be supported by the first annular support element 74, described with reference to Figures 2 to 5. In the example of [Fig. 8], the first element 74 has a main trunk 740 that extends substantially transversely to axis A. The main trunk 740 may include holes 741 for the passage of air (arrow F8). The first element 74 may include a cylindrical wall 746 extending axially upstream, in particular from the main trunk 740. In the example shown, this cylindrical wall 746 supports the stator. More specifically, the cylindrical wall 746 surrounds the stator 70b. The cylindrical wall 746 may include lubrication cavities 747 that may be located on either side of the stator 70b.

[0116] The first element 74 may comprise one or more first annular extensions 742a, 742 extending axially upstream, and one or more second annular extensions 44a, 44b extending axially downstream. In the example shown, the first 742a, 72b and second 744a, 744b extensions extend on either side of the main trunk 740.

[0117] The first element 74 may also include fourth annular extensions 748a, 748b extending axially, respectively, upstream and downstream, in particular from the main trunk 740.

[0118] By way of non-limitation, [Fig. 8] illustrates the first element 74 in which the fourth extensions 748a, 748b extend radially inwards (relative to axis A), the first extensions 742a, 742b extending around the fourth Upstream extension 748a and the second extensions 742a, 742b extend around the fourth downstream extension 748b. The first extensions 742a, 742b can be formed from a first external extension 742a and a first internal extension 742b (relative to axis A) which are coaxial. Similarly, the second extensions 744a, 744b can be formed from a second external extension 744a and a second internal extension 744b (relative to axis A) which are coaxial.

[0119] The fourth upstream extension 748a can form the outer ring of the upstream bearing 47 carried by the first element 74 and the fourth downstream extension 748b can form the outer ring of the downstream bearing 49 carried by the first element 74.

[0120] With reference to [Fig.7], the first 742a, 742a, second 744a, 744b and fourth 748a, 748b extensions of the first element 74 are arranged in the form of a chicane in the cone 29.

[0121] In the example shown, the main trunk 740, the cylindrical wall 746, the first extensions 742a, 742b, the second extensions 744a, 744b and the fourth extensions 478a, 748b can be made in one piece (i.e. from a single piece of material).

[0122] The first support element 74 may have one end fixed to the second enclosure Z. For example, a flange 749 of the first element 74 is fixed to the housing 292 of the cone on the [Fig.7], in particular by means of a ferrule 294. For example, the flange 749, the ferrule 294 and the housing 292 of the plug are connected to each other by fasteners 770 (such as screws).

[0123] The rotor 70a may have a general annular shape extending around the axis A. The rotor 70a may be carried by the second support element 72, as described with reference to figures 2 to 5.

[0124] The second support element 72 may include a cylindrical wall 72a surrounded by the rotor 70a and fixed to the inner periphery of the rotor 70a. The second support element 72 may include a radial wall 72b (with respect to axis A). This radial wall 72b may have an outer periphery (720a) fixed to the cylindrical wall 72a (with respect to axis A). The radial wall may also have an inner periphery (720b) ​​connected to the shaft 58 (with respect to axis A).

[0125] The second element 72 may comprise one or more annular third extensions 724a, 724b extending axially upstream. In the example of [Fig. 8], the third extensions 724a, 724b are formed of an external third extension 724a and an internal third extension 24b (with respect to axis A) which are coaxial. The rotor 70a extends radially around these second extensions 724a, 724b.

[0126] In the example shown, the cylindrical wall 72a, the radial wall 72ba, the third extensions 724a, 724b and the shaft 58 can be monobloc (i.e. (coming from matter).

[0127] The shaft 58 may include one or more fifth extensions 58a, 58b extending annularly with respect to the axis A. By way of non-limiting agreement, [Fig. 8] illustrates that the shaft 58 is formed as a single unit with the fifth extensions 58a, 58b. In particular, the shaft 58 (especially with the fifth extensions 58a, 58b), the second element 72 (especially with the cylindrical wall 72a and radial wall 72b and the third extensions 724a, 724b) and the rotor 70a are formed as a single unit. Alternatively, the shaft 58 and the second element 72 (which can be integral with the cylindrical walls 72a and radial wall 72b and the third extensions 724a, 724b) are two separate parts which are joined together by a connection (such as a screw-bolt type fixing).

[0128] Seals 87a, 87b, can each be located between one of the second extensions 744a, 744b and one of the third extensions 724a, 724b. Seals 89a, 89b can each be located between the first extensions 742a, 72b and the shaft 58, in particular on the fifth extensions 58a, 58b. These seals 87a, 87b, 89a, 89b can be dynamic labyrinth seals or JRS seals.

[0129] Without limitation, [Fig. 8] illustrates the second enclosure Z comprising: - a first joint 87a located downstream between the second external extension 744a and the third extension 724a, - a second joint 87b located downstream between the second internal extension 744b and the third extension 724b, the first joint 87a extending notably above the second joint 87b, - a third joint 89a located upstream between the first external extension 742a and the fifth upstream extension 58a, and the third joint 89a is notably opposite the first joint 87a, - a fourth joint 89b located upstream between the first internal extension 742b and the fifth downstream extension 58b, and the third joint 89a extends notably above the fourth joint 89b and opposite the second joint 87b, - the upstream bearing 47 located between the fourth upstream extension 748a and the shaft 58, the fourth joint 89b extending notably above the upstream bearing 47, and - the downstream bearing 49 located between the fourth downstream extension 748b and the shaft 58, the second joint 87b extending in particular above the downstream bearing 49.

[0130] In the example shown, the pressurization chamber G extends between the fifth downstream extension 58b, the first internal extension 742b, the second internal extension 744b, the third internal extension 724b, and at least a portion of the radial wall 72b, which thus form the boundary walls of the pressurization chamber G. The second chamber Z may extend between the fifth upstream extension 58a, the first external extension 742a, and the cylindrical wall 72a, which thus form the walls delimitation of the second enclosure Z.

[0131] As mentioned above, the second enclosure Z is a ventilation enclosure, that is to say that at least one airflow circulates in this enclosure Z from at least one air inlet to at least one air outlet.

[0132] In the example shown in Figures 7 to 10, the air inlet 80 is located at the inner periphery of the second enclosure Z (arrow 1), and / or via the third sealing joint 89a (arrow F10), for example located at the bearing 47. This air inlet 80 can be formed by at least one opening 800 on the shaft 58, in particular upstream of the pressurization chamber G. The air inlet 80 can be located between the two fifth extensions 58a, 58b. One or more air outlets 82, 83 are located at the outer periphery of the second enclosure Z. These air outlets 82, 83 can be formed, for example, by at least one opening 820, 830. In the example of Figures 8 and 9, one or more first openings 820 are provided on the cylindrical wall 74a (arrow F3), in particular downstream of the stator 70b, to form a first outlet 82. In the example of [Fig.10], one or more additional second openings 830 are provided on the cylindrical wall 74a (arrow F30), particularly upstream of the stator 70b, to form a second outlet 83. .

[0133] The airflow entering the second chamber Z through the inlet 80 flows from the inner periphery to the outer periphery and joins the first outlet 82 (arrow F3) by passing through the air gap 84 of the electrical machine 70 (arrow F2). In particular, [Fig. 8] illustrates airflows entering the second chamber E, notably by passing through the inlet 80 (arrow 1) and / or the third seal 89a (arrow F10) to pass through the bores 741 (arrow F8) and / or the fourth seal 89b (arrow 7) in the pressurization chamber G. The airflow, having passed through the bores 741, passes through the first seal 87a (arrow F) and / or the second seal 87b in the pressurization chamber G (arrow F9). The airflow having passed through the first joint 87a, passes through the air gap 84 (arrow F2) to reach the first outlet 82 (F3).

[0134] As described with reference to the first aspect of the invention, the airflow F2 is likely to contain suspended metallic particles, for example, generated by wear of the bearings and / or seals of the turbomachine. During the passage of the airflow F2 through the air gap 84, these particles are likely to be deposited on the permanent magnets of the rotor 70a (in the example shown) or the stator 70b of the electric machine 70, and to alter the dimensions of this air gap 84.

[0135] The turbomachine includes an electronic module 170 which can be disposed downstream of the electric machine 70. This electronic module 170 allows the electric machine 70 to be controlled and power to be transmitted.

[0136] The second aspect of the present invention also proposes a solution to this problem, two preferred embodiments of which are shown in Figures 9 and 10.

[0137] Figures 9 and 10 illustrate, respectively, first and second non-limiting examples of positioning and realization of the particle trap 100 according to the second aspect of the invention.

[0138] In a manner almost identical to the first aspect of the invention, the second aspect of the invention proposes to install a magnetic trap 100 for metallic particles in the second enclosure Z, this trap 10 being configured to attract and retain the metallic particles contained in the airflow Fil, F2 before its passage through the air gap 84.

[0139] The particle trap 100 may include a ring of magnets 102 extending around the axis A. As described with reference to [Fig.5], the ring of magnets 102 of the second aspect of the invention may also be located on a circumference C whose diameter D is between Dmin and Dmax, which are respectively the minimum diameter and the maximum diameter of the electrical machine 70.

[0140] The ring of magnets 102 may include a support ring 104 and a plurality of magnets 106 evenly distributed on the support ring 104 and around the axis A. The magnets 106 may be fixed to the support ring 104 by gluing or by fasteners, for example. Preferably, the magnets 106 are fixed to a flat surface of the support ring 104. This ring 104 may then be attached to the second external extension 744a.

[0141] As described with reference to [Fig. 6], the ring of magnets 102 is fixed to a wall of the second enclosure Z, which is the first support element 74, in particular on the second external extension 744a, in the example shown. The fixing is, for example, achieved by screws or rivets that pass through openings 108 in the support ring 104 and aligned openings or blind holes in the first element 74. The support ring 104 preferably has an annular surface that complements (for example, frustoconical and smooth) that of the wall to which it is applied and fixed. The openings 108 are also preferably regularly distributed among the magnets 106, each opening 108 being, for example, located between two adjacent magnets 106. For example, the screws have their heads located in the second Z enclosure and are preferably flat or configured to limit pressure losses and turbulence in this area.

[0142] In the examples in Figures 9 and 10, the trap 100 is located on the second external extension 744a at the level of the first joint 87a, which allows the passage of the airflow Fil, F2, which may be laden with metallic particles. The trap 100 is therefore preferably placed on a narrow section of the air passage in order to capture the metallic particles more efficiently and quickly before they reach the air gap 84. The metallic particles are preferably trapped in the trap 100 without risk of obstructing the airflow passage Fl 1. Figure 9 thus illustrates the dashed arrows Fl 1, F2 corresponding to the airflow passing through or having passed through the trap 100.

[0143] Although the trap 100 is installed close to the electric machine 70, the magnets of the trap 100 have little impact on the field lines of the machine 70. The impact on the machine 70 can depend on several factors, such as the power of the magnets for particle recovery, the proximity between the magnets and the rotor, etc.

[0144] Advantageously in the second aspect of the invention, another airflow F6, F60 is provided to bypass the air gap 84 and directly join at least one of the first and second outlets 82, 83 of the second enclosure Z. For this purpose, the radial wall 72b of the second element 72 has through orifices 110 for the passage of this other ventilation airflow F6 ([Fig.9]) and / or the cylindrical wall 74a of the first element 74 has the second opening(s) 830 for the passage of this other ventilation airflow F60 ([Fig.10]).

[0145] In the example of [Fig.9] representing a first embodiment, the orifices 110 are located between the cylindrical wall 72a and the third external extension 724a of the first support element 72, in particular downstream of the trap 100. This makes it possible to direct at least part of the airflow passing through the first seal 87a directly towards the orifices 110. Furthermore, this configuration of the orifices 110 makes it possible to better control the air pressure in the pressurization chamber G and to keep the second ventilation chamber Z and the pressurization chamber G independent.

[0146] These orifices 110 are preferably regularly distributed around the axis A. They are preferably arranged in pairs, the orifices 110 of each pair being diametrically opposed with respect to the axis A. This makes it possible to limit the risk of an imbalance appearing in the cone 29, due to the presence of these orifices 110.

[0147] Preferably, the flow rate of the airflow F6 is greater than the flow rate of the airflow Fil, F2. To achieve this, each of the orifices 110 can have a diameter Duo greater than a diameter D84 of the air gap 84 passage section. This notably increases the flow rate of the airflow F6 bypassing the air gap 84. Thus, a smaller quantity of the airflow Fil (particularly compared to the quantity of the airflow F6) carrying the metallic particles can flow towards the air gap 84, thereby reducing the fouling of the trap 100.

[0148] As an alternative or in addition to the positions of the orifices 110 illustrated in [Fig. 9], through-hole orifices 110 for air passage can be provided on the radial wall 72b, particularly between the third extensions 724a, 724b. In this configuration, the diameter DnO can be at least equal to the diameter D84 of the air gap 84. This makes it possible, in particular, to direct at least a portion of the airflow F9 through these orifices 110 directly towards the first outlet 82.

[0149] In the example of [Fig. 10] representing a second embodiment, a second outlet 83 is located on the cylindrical wall 74, in particular between the main trunk 740 and the electric machine 70, on the opposite side from the first outlet 82. The second outlet 83 is preferably located upstream of the trap 100. This allows at least part of the airflow passing through the trap 100 to be directed directly towards the second opening(s) 830. Furthermore, this configuration has the advantage of not penetrating the radial wall 72b that supports the rotor 70a, while protecting the air gap 84 from an excessive flow of air contaminated with metallic particles. Indeed, the entire airflow Fil passes through the trap 100 so that a greater quantity of metallic particles is captured by the trap 100. This airflow Fl 1 splits into an airflow F60 which joins the second outlet 83, and an airflow F2 which passes through the air gap 84 and joins the first outlet 82.

[0150] Similar to the orifices 110 of [Fig.9], the second opening(s) 830 are preferably regularly distributed around the axis A. They are preferably arranged in pairs, the second opening(s) 830 of each pair being diametrically opposed with respect to the axis A.

[0151] Preferably, the air flow rate F60 is greater than the air flow rate F2. For this reason, each of the second openings 830 can have a diameter D830 greater than the diameter D84 of the air gap passage section 84.

[0152] According to a third embodiment not illustrated in the figures, the second enclosure Z can include both the second openings 830 made on the cylindrical wall 74a and the orifices 110 made on the radial wall 72b, as described with reference to Figures 9 and 10.

[0153] Advantageously, the turbomachine 10 of the invention may include the electric machine 70 described with reference to Figures 5 and 6 (and therefore installed downstream of the blower 14) and / or the electric machine 70 described with reference to [Fig.9] and / or [Fig.10] (and therefore installed in the cone 29).

[0154] The invention also relates to a method of maintaining the turbomachine 10 comprising a step in which the particle trap 100 (according to the first aspect and / or the second aspect of the invention) is disassembled, then cleaned and reassembled, or replaced with a new one.

[0155] For this purpose and by way of example, the blower module, including the blower 14 and the rotor 70a of the electric machine 70, is removed by axial translation upstream. The screws 77 securing the cover 75b to the support 75a are unscrewed and removed. This allows the cover 75b to be detached from the support 75a.

[0156] The hood 75b can then be removed by axial translation upstream.

[0157] The assembly formed by the ferrules 64-68 and the IGV 52 is then removed by axial translation upstream.

[0158] The next step then consists of detaching the flange 76 from the bearing support 62 and the inlet housing 40, in order to be able to access the particle trap 100.

[0159] When the particle trap 100 is installed in the second enclosure Z of the cone 29, at least part of the low pressure body 12a including the shaft 58 and the rotor 70a can be removed to access the trap 100.

Claims

Claims

1. Aircraft turbomachine (10), comprising: - an annular enclosure (Z) for circulating ventilation air, this enclosure extending around a main axis (A) of the turbomachine and comprising at least one air inlet (80) and at least one air outlet (82, 83), - an annular-shaped electrical machine (70) extending around the main axis (A) of the turbomachine, inside the enclosure (Z), and comprising a coaxial rotor (70a) and stator (70b) which define between them an annular air gap (84) for the passage of a first ventilation air flow (F2), characterized in that it further comprises a magnetic trap (100) for metal particles, this trap being located in said enclosure (Z) and being configured to attract and retain the metal particles contained in said first air flow (F2).

2. Turbomachine (10) according to claim 1, in which the particle trap (100) comprises a ring of magnets (102) extending around the main axis (A) of the turbomachine.

3. Turbomachine (10) according to claim 2, in which the ring of magnets (102) comprises a support ring (104) and a plurality of magnets (106) regularly distributed on the support ring (104) and around the main axis (A).

4. Turbomachine (10) according to one of the preceding claims, wherein said at least one air inlet (80) is located at an internal periphery of the enclosure (Z), and said at least one air outlet (82, 83) is located at an external periphery of the enclosure.

5. Turbomachine (10) according to one of claims 2 to 4, in which the ring of magnets (102) is fixed to a wall of the enclosure (Z) by removable fixing means.

6. Turbomachine (10) according to any one of claims 2 to 5, in which the ring of magnets (102) is located on a circumference (C) whose diameter (D) is between Dmin and Dmax, which are respectively the minimum diameter and the maximum diameter of the electric machine (70).

7. Turbomachine (10) according to claim 5 or 6, in which the stator (70b) of the electric machine (70) is carried by a first annular support element (74) one end of which is fixed to said wall of the enclosure (Z), and surrounds said crown of magnets (102).

8. Turbomachine (10) according to claim 7, in which the first element (74) comprises, upstream of the ring of magnets (102), openings (830) forming said at least one air outlet (83).

9. A turbomachine (10) according to claim 7 or 8, wherein the rotor (70a) of the electric machine (70) is carried by a second annular support element (72) which comprises a cylindrical wall (72a) surrounded by the rotor (70a) and fixed to the internal periphery of the latter.

10. Turbomachine (10) according to claim 9, in which said cylindrical wall (72a) comprises, on the side opposite the ring of magnets (102), through orifices (110) for the passage of a second flow of ventilation air (F6).

11. A turbomachine (10) according to claim 9, wherein the second annular support element (72) comprises a radial annular wall (72b) whose outer periphery is connected to said cylindrical wall (72a) and whose inner periphery is connected to a drive shaft (58).

12. Turbomachine (10) according to claim 11, in which the radial annular wall (72b) comprises through orifices (110) for the passage of a second ventilation air flow (F6).

13. Turbomachine (10) according to one of claims 11 and 12, in which the first support element (74) comprises first annular extensions (742a, 742b) which extend axially upstream and second annular extensions (744a, 744b) which extend axially downstream, the radial annular wall (72b) of the second support element (72) comprising third annular extensions (724a, 724b) which extend axially upstream, dynamic seals (87a, 87) being provided between the second extensions (744a, 744b) and third extensions (724a, 724b).

14. Turbomachine (10) according to claim 13, in which the radial annular wall (72b) and the drive shaft (58) to which it is connected both delimit a part of said enclosure (Z), dynamic seals (89a, 89b) being provided between the first extensions (742a, 742b) and this drive shaft (58).

15. Turbomachine (10) according to one of the preceding claims, in which the electric machine (70) is mounted downstream of a fan (14) configured to rotate around said main axis (A), the rotor (70a) of the electric machine (70) being integral in rotation with the fan (14), and / or the electric machine (70) is mounted inside an exhaust cone (29) of the turbomachine (10), the rotor (70a) of the electric machine (70) being rotationally fixed to a drive shaft (58) of the turbomachine extending into this exhaust cone (29).

16. Turbomachine (10) according to claim 15, in which the enclosure (Z) is located just downstream of the fan (14), said at least one air inlet (80) being formed by a dynamic seal (86) mounted between an annular bearing support (62) and a drive shaft (32) of the fan, and said at least one air outlet (82) being located in a flow path of an air flow (F) leaving the fan (14), and / or the enclosure (Z) is located inside the exhaust cone (29), said at least one air inlet (80) being formed by at least one dynamic seal (89a, 89b) provided between the first support element (74) and the drive shaft (58), and / or by an opening (800) formed in the drive shaft (58), and said at least one air outlet (82, 83) being located in a flow vein of an air flow (F) leaving the exhaust cone (29).

17. Method for maintaining a turbomachine (10) according to one of the preceding claims, comprising a step in which the particle trap (100) is dismantled, then cleaned and reassembled, or replaced with a new one.

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