Aircraft turbine engine equipped with an electric motor

Abstract

An aircraft turbine engine (10) is disclosed, comprising a gas generator (12) and a fan (14), the fan being arranged upstream of the gas generator (12) and configured to generate a gas inlet flow (F), a portion of which flows into the gas generator to form a main flow (36), the turbine engine (10) comprising an electric motor coaxially mounted downstream of the fan (14), the electric motor comprising a rotor (62a) surrounded by a stator (62b) carried by an annular shroud (64), the shroud (64) being surrounded by a casing (40) of the gas generator, the casing and the shroud (64) together defining a section of a flow duct for the main flow (36), in which fixed blades (42, 68) for straightening the main flow (36) extend.

Description

Technical Field

[0001] The invention relates to an aircraft turbine engine equipped with an electric motor. Background Art

[0002] The prior art includes in particular document FR-A1-2842565, which describes a turbine engine equipped with an electric motor, as well as EP-A2-2270315, US-B2-9,109,452, US-A-3,264,482, FR-A1-2922265, WO-A1-2006 / 0600144 and WO-A1-2015 / 077755.

[0003] The aviation community is currently raising many questions about the practicality of hybrid engines for commercial aviation. The use of electrical energy is now being considered not only for aircraft functions but also for electrifying turbine engines.

[0004] This discussion has prompted the study of hybrid engine architecture solutions, combining fossil fuels and electrical energy to ensure the driving of the propulsion section (the fan of the turbine engine) and the supply of specific engine and / or aircraft functions.

[0005] In particular, these architectures can be based on high bypass ratio and reducer type architectures, but can also be based on multi-body architectures (2 or 3). In these architectures, the turbine engine comprises a low-pressure body and a high-pressure body, each body comprising a shaft connecting the rotor of the compressor to the rotor of the turbine.

[0006] It is known to equip aircraft turbine engines with one or more electric motors, ranging in power from a few kW to several MW, in the high-pressure and / or low-pressure sections of the turbine engine. It will be recalled that an electric motor is an electromechanical device based on electromagnetism, capable of converting electrical energy into work or mechanical energy, for example. This process is reversible and can be used to generate electricity.

[0007] Therefore, depending on the end use of the motor, we use the following terms:

[0008] -A generator is an electric machine that generates electrical energy from mechanical energy.

[0009] -A motor is an electrical machine that generates mechanical energy from electrical energy.

[0010] The electric machine can also operate in motor mode and generator mode.

[0011] The cooling method for electric motors is complex and very important to ensure the correct function of the motor. In particular, it must be consistent with the heat losses that the motor must dissipate.

[0012] In particular, current solutions foresee cooling of the electric stator of the electric machine by the air flow of the turbine engine, associated with an additional complex cooling using oil in order to ensure sufficient cooling of the electric machine.

[0013] The present invention proposes a solution to at least some of the above problems and in particular a solution for improving the cooling of an electric machine without using additional cooling by oil. Summary of the Invention

[0014] The present invention relates to an aircraft turbine engine, comprising a gas generator and a fan, wherein the fan is arranged upstream of the gas generator and is configured to generate a gas inlet flow, a portion of the gas inlet flow flows in a duct of the gas generator to form a main flow, and another portion of the gas inlet flow flows in a duct surrounding the gas generator to form a secondary flow. The turbine engine also comprises an electric motor, which is coaxially mounted downstream of the fan and comprises a rotor surrounded by a stator carried by an annular shroud, the shroud being surrounded by a casing of the gas generator, the casing and the shroud together defining a flow duct for the main flow, in which fixed blades for straightening the main flow extend.

[0015] According to the invention, the shroud and / or the blades comprise elements configured to generate disturbances in the main flow.

[0016] The elements that create a disturbance in the main flow increase the heat exchange coefficient between the main flow and the shroud and / or blades, and thus the heat exchange capacity between the main flow and the motor, without incurring the same load losses as shrouds and / or blades of uniform shape. Consequently, cooling of the shroud and / or blades, as well as cooling of the motor, is improved at an equivalent main flow rate.

[0017] Furthermore, the turbulence or disturbance moves the air closer to the surfaces of the shroud and / or blades to be cooled. The heated air does not stagnate and is directed by the turbulence toward the cooler secondary flow before returning to the surfaces of the shroud and / or blades to be cooled. The resulting vortex refreshes the cool air that comes into contact with the hot surfaces of the motor's shroud and / or blades to be cooled.

[0018] This improves the cooling of the electric machine and can be done entirely by air from the main flow.The invention thus makes it possible to avoid adding an oil cooling circuit, which in particular makes it possible to significantly reduce the weight of the assembly.

[0019] The module according to the present application may include one or more of the following features, which may be independent of each other or in combination:

[0020] - said elements are recessed or protruding on one or more surfaces of said shroud and / or blades, said surface or each of said surfaces being intended to be swept by said main flow;

[0021] - one of said surfaces or each of said surfaces comprises a matrix of identical concave elements distributed in rows and columns (linear or staggered),

[0022] - The cross section of each of said elements has a concave curved shape.

[0023] - each of said elements has a width or dimension D between 2 mm and 30 mm and a depth P less than or equal to D;

[0024] - one of said surfaces or each of said surfaces comprises a series of said elements shaped like elongated grooves extending substantially in the direction of flow of said main flow;

[0025] - the grooves are corrugated;

[0026] - one of said surfaces or each of said surfaces comprises a series of protruding elements formed by fins;

[0027] - the fins are triangular or in the shape of the Greek letter delta;

[0028] - the fins are movable or retractable in order to adjust the disturbances in the main flow;

[0029] - said element comprises a plasma generating actuator situated on one of said surfaces or on each of said surfaces intended to be swept by said main flow;

[0030] - said actuator is fed by said motor;

[0031] - the actuators are evenly distributed around the motor;

[0032] The shroud comprises an inner annular surface surrounding the stator of the electric machine and an outer annular surface, the outer annular surface extending around the inner annular surface and defining the section of the flow duct of the main flow;

[0033] The element is connected to the stator by one or more heat-conducting parts to ensure heat exchange by conduction; in fact, the contact or quasi-contact between the perturbation element, one or two heat-conducting intermediate parts and the stator of the electric machine enables good cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] 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:

[0035] [ Figure 1 ] Figure 1 is a schematic axial cross-section of an aircraft turbine engine having a large bypass ratio and a speed reducer;

[0036] [ Figure 2 ] Figure 2 is a schematic half view of a partial axial section of an aircraft turbine engine equipped with an electric motor;

[0037] [ Figure 3a ] Figure 3a is a schematic diagram of a top portion of an element configured to disrupt airflow through a turbine engine;

[0038] [ Figure 3b ] Figure 3b yes Figure 3a Schematic outline of the components;

[0039] [ Figure 4 ] Figure 4 yes Figure 3b a schematic outline of a variant embodiment of the illustrated element;

[0040] [ Figure 5 ] Figure 5 yes Figure 3b Schematic outlines of alternative embodiments of the elements of; and

[0041] [ Figure 6 ] Figure 6 is a schematic diagram of a plasma actuator;

[0042] [ Figure 7 ] Figure 7 is similar to Figure 2 , showing a half view of a variant embodiment of an aircraft turbine engine equipped with an electric motor;

[0043] [ Figure 8 ] Figure 8 is similar to Figure 2 , showing a half view of a variant embodiment of an aircraft turbine engine equipped with an electric motor;

[0044] [ Figure 9 ] Figure 9 is similar to Figure 2 , showing a half view of a variant embodiment of an aircraft turbine engine equipped with an electric motor. DETAILED DESCRIPTION

[0045] First, refer to Figure 1 , which schematically shows a twin-body, twin-flow aircraft turbine engine 10 .

[0046] The turbine engine 10 generally comprises a gas generator 12 , upstream of which is arranged a fan 14 . The fan 14 is surrounded by a fan case 16 , which in turn is surrounded by a nacelle 18 , which surrounds and extends along a major portion of the gas generator 12 .

[0047] Here, the gas generator 12 includes two bodies, a low-pressure body 12a or BP and a high-pressure body 12b or HP. Each body includes a compressor and a turbine.

[0048] The terms “upstream” and “downstream” should be considered along the main direction F of the gas flow in the turbine engine 10 , this direction F being parallel to the longitudinal axis A of the turbine engine.

[0049] The gas generator 12 includes, from upstream to downstream, 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 low-pressure compressor 20 and the high-pressure compressor 22 are separated from each other by an intermediate casing 61 .

[0051] The fan 14 includes an annular row of blades 30 driven in rotation by a fan shaft 32, which is connected to the rotor of the low-pressure main engine 12a via a speed reducer 33. The fan 14 is configured to generate an inlet gas flow F. A portion of the inlet gas flow flows into a gas generator duct (referred to as the inner duct) to form a radially inner annular flow (referred to as the primary flow 36), which supplies the gas generator 12. Another portion of the inlet gas flow flows in a duct surrounding the gas generator (referred to as the outer duct) to form a radially outer annular flow (referred to as the secondary flow 38), which flows between the gas generator 12 and the nacelle 18 and provides the majority of the turbine engine's thrust. Thus, the inlet gas flow F passing through the fan is separated upstream of the gas generator 12 by an annular separator nose 34 into the primary flow 36 and the secondary flow 38.

[0052] The gas generator housing, referred to as the inlet housing 40, structurally connects the gas generator 12 to the fan housing 16 and the nacelle 18. The inlet housing 40 includes an annular row of radially inner arms 42 extending into the main flow 36 (i.e., into the inner duct), an annular row of radially outer straightener blades 44 (OGV type), and a bladed straightener 174 extending into the main flow 36 downstream of the annular row of arms 42.

[0053] The turbine engine also comprises an annular row of stationary straightening vanes 68 of the main flow 36 , which extend into the inner duct and are arranged upstream of the arms 42 .

[0054] The number of arms 42 is usually limited (less than ten) and is tubular and traversed by the auxiliary element. The number of blades 44 (OGV) is generally higher than ten.

[0055] The fan shaft 32 is guided in rotation upstream by bearings 46, 48. These bearings 46, 48 are of the spherical or roller type, each comprising an inner ring mounted on the shaft to be guided, an outer ring carried by an annular bearing support and rolling elements between these rings.

[0056] As is known, the reducer 33 is of epicyclic gear type and comprises a sun gear 33a centered on the axis A, a ring gear 33b extending around said axis, and planetary gears 33c meshing with the sun gear and the ring gear and carried by a planetary carrier 33d (reference numerals 33a-33d in FIG. Figure 2 (see in the ).

[0057] In the example shown, the ring gear 33b is fixed and fixedly connected to the support 52 of the bearings 46, 48. The planet carrier 33d is rotatable and connected to the fan shaft 32 of the reducer, which also includes an input shaft 56 meshing with the sun gear 33a. The input shaft 56 is connected to the main shaft 58 of the low-pressure body.

[0058] The input shaft 56 is guided by bearings 50 which are carried by bearing supports 60 ( Figure 1 ).

[0059] The bearing supports 52 , 60 extend about the axis A and are fixed components connected to the inlet housing 40 .

[0060] Figure 2 yes Figure 1 14. FIG. 14 is an enlarged view of a portion of FIG. 14, particularly an enlarged view of a region Z located between the fan disk 32a and the speed reducer 33, where the motor 62 is installed. The motor 62 is coaxially installed downstream of the fan 14.

[0061] In addition to being axially delimited upstream by the fan disk 32 a and downstream by the speed reducer 33 , this annular zone Z is delimited radially inside by the fan shaft 32 of the speed reducer and radially outside by elements that internally delimit the flow duct of the main flow 36. These elements include an annular shroud 64 located upstream and an inner annular wall 66 located downstream, which is connected to the radially inner end of the arm 42.

[0062] The wall 66 extends as an extension of the shroud 64 , which is an inner shroud and is connected to an outer shroud 70 , forming part of the inlet casing 40 , by an annular row of stationary straightening vanes 68 of the main flow 36 extending into the inner duct.

[0063] The shrouds 64 and 70 define between them an air inlet of the flow duct of the main flow 36. The shroud 70 extends between the aforementioned separator nose 34 and an outer annular wall 72 located downstream of the shroud 70, and forms part of the inlet casing 40 when it is connected to the radially outer end of the arm 42. The shroud 64 is thus surrounded by the inlet casing 40, which together with the shroud 64 defines a section of the flow duct of the main flow 36.

[0064] The annular region Z is divided into two annular sections, one upstream and one downstream, by a bearing support 52. In the example shown, this support has a generally frustoconical shape that widens toward the downstream. Its upstream radially inner end carries the outer ring of the bearing 46, the inner ring of which is attached to the fan shaft 32. The downstream radially outer end of the support 52 is attached to the inlet casing 40.

[0065] The outer ring of bearing 48 is attached to support portion 52 approximately in the middle, while the inner ring is attached to fan shaft 32. To this end, bearing support portion 52 includes two annular extensions, namely upstream extension 52a and downstream extension 52b. Upstream extension 52a extends from bearing 46 to a radially outer annular flange 52aa, while downstream extension 52b extends from radially inner annular flange 52ba to a radially outer annular flange 52bb for attachment to the upstream end of inlet casing 40.

[0066] The outer ring of the bearing 48 is attached to a ring 74 comprising a radially outer annular flange 74a interposed between flanges 52aa and 52ba. These flanges 52aa, 74a, 52ba are applied axially against each other and comprise orifices for the passage of screw-nut type connection means.

[0067] The downstream section of the zone Z represents the portion of the lubricating enclosure for the bearings 46, 48 and 50 and the reducer 33 housed in this enclosure, arranged axially between the bearings 46, 48 and 50. This enclosure is filled with oil mist.

[0068] The upstream section of the zone Z represents the installation location of the electric motor 62 , which is therefore separated from the enclosure E by the bearing support 52 .

[0069] The motor 62 has a generally annular shape and comprises a rotor 62 a and a stator 62 b. The rotor 62 a has a generally cylindrical shape extending about an axis A and is carried by a support element 76 , which itself has a generally cylindrical shape. The rotor 62 a is arranged around this element 76 .

[0070] Stator 62b also has a generally cylindrical shape and is integral with an annular member 78 having a generally C-shaped axial cross-section. Member 78 comprises two annular portions, an inner portion 78b and an outer portion 78a, extending around one another and connected at their downstream ends by an annular base 78c. Member 78 thus defines an opening oriented axially upstream, within which rotor 62a and support element 76 are housed.

[0071] The stator 62 b is integral with or forms an outer portion 78 a of the component. The outer portion 78 a is directly surrounded by the shroud 64 .

[0072] Portion 78b of member 78 extends radially inwardly from rotor 62a, and support element 76 and bearings 80,82 are mounted between this element 76 and portion 78b to rotationally guide rotor 62a relative to stator 62b. Portion 78b thus forms a support for bearings 80,82.

[0073] Here, the number of bearings 80, 82 is two and they are axially spaced apart from each other. The upstream bearing 80 is a rolling bearing and the downstream bearing 82 is a ball bearing.

[0074] An annular closure element 84 is mounted and attached to the upstream end of the support element 76 .

[0075] This closing element 84 has a substantially radial orientation and is attached at its periphery to the upstream end of the element 76. The element 84 comprises at its periphery a cylindrical rim 84a fastened axially against an inner annular rib of the support element 76 by a nut 86 mounted axially from upstream.

[0076] The inner periphery of element 84 has an inner diameter that is smaller than the main inner diameter of component portion 78b and carries a series of inner linear splines 88. The inner periphery of element 84 also includes an annular web 84b that extends axially downstream and sealingly cooperates with the upstream end of portion 78b. The seal is ensured by a labyrinth seal, the annular scraper of which is carried, for example, by web 84b, and the abradable coating is carried by portion 78b.

[0077] An annular connecting element 90 is used to drive the rotor 62a. This element 90 is generally cylindrical and comprises, at its upstream end, an annular flange 90a for attachment to the fan disk 32 and, at its downstream end, a series of splines 90b for connection to the splines 88 of the closure element 84.

[0078] Advantageously, the splines 88, 90b may be rotational to isolate the motor from the rest of the motor as much as possible.

[0079] Advantageously, bearings 80, 82 are located and lubricated within a small annular lubrication enclosure, which is sealed upstream by a seal between web 84b and portion 78b, and downstream by a seal between web 78ca and element 76. Lubricating oil for bearings 80, 82 is provided to drain from this small enclosure through axial holes 92 provided in base 78c, located just inside the inner periphery of webs 78ca and 78cb. These holes 92 allow oil to enter the annular space extending between base 78c and extension 52b of bearing support portion 52. Extension 52b is further provided with an axial hole 94, generally opposite holes 92, to allow oil to enter the enclosure and to drain oil from the enclosure when it is drained. It will therefore be appreciated that lubricating oil for bearings 80 , 82 will flow centrifugally to web 78 ca , through aperture 92 , onto web 78 cb , and then through aperture 94 to the lubrication enclosure of reducer 33 .

[0080] The oil may be drained through one of the arms 42 of the inlet housing 40. The other of the arms 42 may be used to deliver oil for feeding the bearings 80, 82 to the aforementioned micro enclosure.

[0081] The stator 62 b is connected to the control circuitry by a cable 96 , where the cable 96 passes through the tubular arm 42 of the inlet housing 40 .

[0082] The stator 62 b is carried by an annular shroud 64 .

[0083] Thus, the motor 62 is in direct contact with the shroud 64 and, through the shroud 64, with the blades 42, 68. Thus, the motor 62 can be cooled by the main flow 36 in contact with the shroud 64 and the blades 42, 68.

[0084] The convective heat exchange that enables cooling of the motor is as follows:

[0085] Flux = h*S*(Tm-Ta)

[0086] in:

[0087] - Flux: heat flux exchanged

[0088] -h: exchange coefficient

[0089] -S: swap surface

[0090] - Tm: temperature of the metal to be cooled (ie, in this case, the temperature of the shroud 64 and / or blades 42, 68)

[0091] Ta: cooling air temperature (ie, here the temperature of the main flow 36 )

[0092] Therefore, in order to increase the exchanged heat flux to improve the cooling of the electric machine 62 , the exchange coefficient h or the exchange surface S, or both, can be increased (the air temperature Ta is determined by the temperature at the fan outlet).

[0093] like Figures 3a to 6 As shown, according to the invention, the shroud 64 and / or the blades 42, 68 comprise elements 100 configured to generate disturbances in the main flow 36. The elements 100 are configured to increase the exchange coefficient h and / or the exchange surface S between the main flow 36 and the electric machine.

[0094] The exchange surfaces between the main flow 36 and the electric machine include the surface of the inner duct of the housing surrounding the stator of the electric machine, i.e., the surface of the shroud 64 and the surfaces of the blades 42, 68 serving as cooling fins. Thus, the element 100 is located on one or more exchange surfaces 150 located on the shroud 64 and / or the blades 42, 68 swept by the main flow 36.

[0095] For example, the element 100 is recessed or protruding on the surface 150 of the shroud 64 and / or the blades 42, 68. The hollow or protruding shape of the element 100 enables it to act both as a disturber of the main flow 36 to increase the exchange coefficient and to increase the exchange surface between the main flow and the motor.

[0096] like Figure 3a and Figure 3b As shown, for example, one surface 150 or each of the plurality of surfaces 150 includes a matrix of identical concave elements 100 arranged in rows and columns. Each element 100 has a concave, curved cross-section, for example, and represents a specific example of a concave element. It has a "golf ball"-like structure with a series of grooves, the depth and diameter of which are determined by cooling requirements.

[0097] Here, each element 100 has a width or dimension D, measured in the flow direction of the main flow 36 and comprised between 2 mm and 30 mm, and a depth P less than or equal to D.

[0098] The elements 100 are spaced apart from each other by a dimension L1 in the flow direction of the main flow 36 , and spaced apart from each other by a dimension L3 in a direction perpendicular to the flow direction of the main flow 36 .

[0099] The parameters D, L1, L2 and P are selected to achieve the best compromise between cooling performance, manufacturing, aerodynamic impact in the duct and cost criteria. In addition, these dimensions can also be variable in the surface 150 to achieve the best size setting.

[0100] The above example considers using grooves to increase the exchange surface, but it is also possible to use protrusions instead of grooves, following the same principle. Then the depth parameter is replaced by the height parameter to determine the size of the protrusion.

[0101] All or part of the surface 150 may benefit from such a shape. In particular, the surface of the shroud 64 is preferably above the surfaces of the blades 42, 68 to limit the impact on performance.

[0102] This solution, which comprises a matrix of identical concave elements 100 distributed in rows and columns, focuses on the increase of the exchange surface, but also acts on the exchange coefficient. Indeed, when in contact with a non-smooth surface, the flow tends to become turbulent, which increases the exchange coefficient.

[0103] like Figure 4 As shown, for example, one of the surfaces 150 or each of the plurality of surfaces 150 comprises a series of elements 100 shaped like elongated grooves 110 extending generally in the direction of flow of the main flow 36. In particular, the elements extend longitudinally in the direction of flow of the main flow 36. Preferably, the grooves are oriented in the direction of flow so as not to interfere too much with the flow in the conduit, but grooves orthogonal to the direction of flow are also contemplated.

[0104] In the same way as the “golf ball” shape, the element 100 shaped like a groove 110 makes it possible to increase the exchange surface and the exchange coefficient, thus improving the cooling of the electric machine.

[0105] The grooves 110 integrated into the cooling surface can be straight or corrugated in order to achieve more exchange surface.

[0106] In the same manner as before, elements 100 shaped like grooves may be positioned on all or part of the surface 150 to increase the surface.

[0107] If the production of the surface 150 is simplified and the amount of material is limited by shaping the element 100 like the groove 110 , it is also possible to provide the element 100 in the form of bridges on one or more surfaces 150 , in particular by additive manufacturing.

[0108] like Figure 5 As shown, one of said surfaces 150 or each of said surfaces 150 comprises a series of protruding elements 100 formed by fins 120 .

[0109] By disturbing the main flow 36, these fins 120 increase the exchange coefficient and thus the exchange capacity without causing the same pressure drop as a uniformly shaped surface 150. In addition, the turbulence makes it possible to move the air near the surface 150. The warm air does not stagnate, but flows through the turbulence towards the cooler secondary flow and then back towards the surface 150. The vortex thus generated refreshes the cool air in contact with the hot surface 150 of the shroud of the motor.

[0110] For example, the fin 120 has a triangular or delta (Δ) shape, which is conducive to generating a strong vortex.

[0111] The fins 120 will create a pressure drop like exchanger fins, but will be movable or retractable to accommodate disturbances in the main flow 36 .

[0112] The circumferential density of the fins 120 will depend on the desired level of heat exchange and pressure drop. In particular, the fins 120 may be arranged in multiple rows to maximize heat exchange.

[0113] The exemplary embodiment here comprises an element 100 shaped like a fin 120, but several other shapes of perturbators are possible. Preferably, like the fin 120, the element 100 is a perturbator of the "vortex generator" type.

[0114] like Figure 6 As can be seen in FIG, the element 100 includes a plasma generating actuator 130 located on one or more of the surfaces 150 intended to be swept by the main flow 36. Ideally, the actuators 130 are powered by the motor 62, but another power source may also be used to power the actuators. The actuators each include a covered electrode 131 and an exposed electrode 132, which are offset from each other in the direction of flow of the main flow 36. The covered electrode 131 is separated from the exposed electrode 132 by a dielectric material 133, and the covered electrode is located in a support 134.

[0115] The actuators 130 are evenly distributed around the motor 62 , for example, evenly distributed around the circumference of the shroud.

[0116] The plasma actuator 130, activated by applying an electric current, causes a disturbance in the local flow velocity, which develops into turbulence downstream. This enables the main flow 36 to flow without requiring any mechanical components and without generating significant heat.

[0117] Compared to other flow control technologies previously proposed, these electric actuators 130, which have no movable parts and are arranged along the circumference of the shroud, can accelerate the air over the shroud and blades 42, 68, thereby enhancing heat exchange, while having little or no disturbance to the flow of the main flow 36 itself when not activated. On the other hand, the use of these actuators 130 makes it possible to actively control the cooling efficiency by sending more or less (or even no) current to disturb the flow of the main flow 36 to a greater or lesser extent.

[0118] exist Figures 7 to 9 The illustrated alternative embodiment of the invention represents an embodiment of the invention in which the electric motor 62 is located downstream of the speed reducer.

[0119] Figure 7 A variant embodiment is shown in which the zone Z is located downstream of the speed reducer 33 and upstream of the intermediate housing 61 .

[0120] This annular zone Z is radially delimited internally by the main shaft 58 of the low-pressure body 12a and the input shaft 56 of the reducer 33, and externally by the elements that internally define the flow duct I of the main flow 36. These elements comprise, from upstream to downstream, the inner annular wall 66a, the annular shroud 64a, then the disk 172a of the wheel 172 and the inner platform 174a of the bladed straightener 174 of the low-pressure compressor 20.

[0121] Wall 66a surrounds reducer 33 and is part of inlet housing 40, as it is connected to the radially inner ends of arms 42, the radially outer ends of which are connected to another outer annular wall 66b. Shield 64a extends around motor 62 and is an extension of wall 66a.

[0122] The shroud 64a is an inner shroud and is surrounded by an outer shroud 64b, the shrouds 64a and 64b defining between them a section of the flow duct I of the main flow 36, which is located downstream of the inlet casing 40 and upstream of the low-pressure compressor 20 and the intermediate casing 61. The shroud 64b extends from the downstream end of the wall 66b to the wall 20a surrounding the wheel 172 and the straightener 174 of the low-pressure compressor 20. The shroud 64b can be connected to this wall 20a or be integral with it.

[0123] Typically, this wall 20 a comprises means 176 for guiding the blades of a straightener 174 in rotation substantially about a radial axis and for variable pitch of the blades of the straightener, as well as an abradable annular coating 178 surrounding the wheel 172 .

[0124] The downstream end of the shroud 64a is also connected or attached to means 176 for guiding the straightener blades 174 in rotation about the same axis.

[0125] The disk 172 a of the wheel 172 of the compressor 20 is connected to a trunnion 188 which is driven by the shaft 58 via an intermediate shaft 190 .

[0126] Trunnion 188 is annular in shape, with a generally T-shaped axial cross-section. It includes a radial annular branch 188a, the inner periphery of which is connected to a cylindrical branch 188b. The outer periphery of radial branch 188a is screwed to the flange of disk 172a of wheel 172, while cylindrical branch 188b includes an internal spline 188c for connecting to the external spline of intermediate shaft 190.

[0127] Intermediate shaft 190 is generally tubular in shape and includes an upstream extension 190a and a downstream extension 190b. Trunnion 188 is mounted on downstream extension 190b of intermediate shaft 190. This downstream extension 190b includes internal splines 190c for connection to external splines of main shaft 58, and a cylindrical shoulder 190d for axial support of trunnion 188 downstream, specifically at the downstream end of the trunnion's cylindrical branch 188b. Intermediate shaft 190 may also include an outer cylindrical surface 190e for centering branch 188b and trunnion 188.

[0128] An upstream extension 190a of the intermediate shaft 190 extends around the downstream end of the input shaft 56 of the reducer 33. The input shaft 56 includes internal splines 56a for connection to the external splines of the main shaft 58. In addition, a nut 192 is axially fastened to the upstream end of the main shaft 58 and axially supported on the input shaft 56 so that the input shaft is axially fastened against the intermediate shaft 190, which itself is axially supported on the cylindrical shoulder 170a of the main shaft 58.

[0129] At its downstream end, the intermediate shaft 190 carries the inner ring 50a (with balls) of the bearing 50, the outer ring 50b of which is carried by a bearing support 60. This support 60 is generally frustoconical in shape and gradually expands axially toward the downstream. The downstream end of the support, which has a larger diameter, is attached to the intermediate housing 61.

[0130] This type of bearing 50 is usually lubricated and located in an annular lubrication enclosure that is sealed to prevent any oil leakage upstream, in particular upstream, in the implantation zone Z of the electric machine 62 .

[0131] Here, the rotor 62a is attached to an annular member 194 that extends about the axis A.

[0132] The axial cross-section of member 194 is generally T-shaped. Member 194 includes a radial annular branch 194a, the inner periphery of which is connected to a cylindrical branch 194b. The outer periphery of radial branch 194a is attached to rotor 62a via screws, and cylindrical branch 94b includes an internal spline 194c, which is used to connect to the external spline of intermediate shaft 190, specifically the external spline of the upstream extension 190a of the intermediate shaft.

[0133] The downstream end of the cylindrical branch 194 b is axially supported on the upstream end of the cylindrical branch 188 b of the trunnion 188 and cooperates with a cylindrical centering surface 190 e carried by the intermediate shaft 190 .

[0134] A nut 196 is axially secured to the upstream end of the intermediate shaft 190 and is axially supported on the member 194 to axially bias the member against the trunnion 188 .

[0135] At its upstream end, the cylindrical branch 194 b of the member 194 carries the inner ring 198 a (with rollers) of a bearing 198 , the outer ring 198 b of which is carried by another annular bearing support 200 . This support 200 is generally frustoconical in shape and gradually expands axially towards the upstream. The upstream end of this support, which has a larger diameter, is connected to the stator 62 b of the motor 62 .

[0136] The stator 62b includes at its upstream end a radially inner annular flange for attaching a plurality of flanges, including one flange 200a of the bearing support 200. The flange 62ba of the stator 62b is also attached to the flange 40a of the inlet housing 40, and to the sealing cover 202 and / or flanges of the deflector.

[0137] The inner periphery of the bearing support 200 may be equipped with an oil film damping system 204 (called squeeze film).The bearing support may further comprise a cylindrical peripheral edge 200b facing downstream and comprising an inner annular coating of an abradable material.

[0138] Two annular sealing covers 206 can be attached to the member 194 (in particular to the radial branch 194a of the member) and carry radially outer annular scrapers that are intended to cooperate with the coating carried by the peripheral edge 200b and with a similar coating carried by one of the covers 202 attached to the flange 62ba of the stator 62b.

[0139] The bearings 198 are typically lubricated and are located in an annular lubrication enclosure that is sealed to prevent any leakage of oil (particularly downstream) into the implantation zone Z of the electric machine 62 .

[0140] The stator 62 b is connected to the control circuitry by a cable 96 , where the cable 96 passes through the tubular arm 42 of the inlet housing 40 .

[0141] like Figure 2 As in the exemplary embodiment shown, the motor 62 , in particular the stator 62 b thereof, is arranged as close as possible to the main flow 36 , thereby achieving a motor that is cooled by the main flow 36 .

[0142] Figure 8 An alternative embodiment of a turbine engine according to the invention is shown.

[0143] Elements described above and in this embodiment are denoted by the same reference numerals.

[0144] The implantation zone Z of the motor 62 is located downstream of the speed reducer 33 and the compressor 20 , and upstream of the intermediate housing 61 .

[0145] This annular zone Z is radially delimited on the inside by the main shaft 58 of the low-pressure body 12a and the input shaft 56 of the reducer 33, and on the outside by the elements that internally define the flow duct I of the main flow 36. Here, these elements comprise, from upstream to downstream, the disk 172a of the wheel 172 and the inner platform 174a of the bladed straightener 174 of the low-pressure compressor 20, the annular shroud 64a, and then the inner annular wall 208b.

[0146] The wall 208b is part of the intermediate housing, since the arm is connected to the radially inner end of an arm 210, the radially outer end of which is connected to another outer annular wall 208a. The shroud 64a extends around the motor 62 and is an extension of the disk 172a of the wheel 172 and of the inner platform 174a of the bladed straightener 174 of the compressor 20.

[0147] The shroud 64a is an inner shroud and is surrounded by an outer shroud 64b, the shrouds 64a, 64b defining between them a section of the flow duct I of the main flow 36, which is situated downstream of the low-pressure compressor 20 and upstream of the intermediate casing 61. The shroud 64b extends from the downstream end of the wall 20a to an outer annular wall 208a which is connected to the radially outer end of the arm 210 and thus forms part of the intermediate casing 61. The shroud 64b may be connected to this wall 20a or be integral with it.

[0148] Typically, this wall 20 a comprises means 176 for guiding the blades of a straightener 174 in rotation substantially about a radial axis and for variable pitch of the blades of the straightener, as well as an abradable annular coating 178 surrounding the wheel 172 .

[0149] The shroud 64 a comprises, at its upstream end, a cylindrical peripheral edge 212 oriented upstream and carrying an annular coating of abradable material intended to cooperate with a scraper 180 d carried by a disk 172 a of the downstream wheel of the compressor 20 .

[0150] The disk 172 a of the wheel 172 of the compressor 20 is connected to a trunnion 188 which is driven by the shaft 58 via an intermediate shaft 190 .

[0151] The stator 62b comprises, at its downstream end, an annular flange 62ba for attaching a plurality of flanges, one of which is the inner annular wall 208b. The flange 62ba of the stator 62b is also attached to a flange of the bearing support 60.

[0152] The inner periphery of the bearing support 60 may be equipped with an oil film damping system 204 (referred to as a squeeze film).

[0153] The bearings 198 are typically lubricated and are located in an annular lubrication enclosure that is sealed to prevent any leakage of oil (particularly downstream) into the implantation zone Z of the electric machine 62 .

[0154] The stator 62 b is connected to the control circuit by a cable 96 which passes through the tubular arm 110 of the inlet housing 61 .

[0155] As in the previous embodiment, the radially outer surface of the shroud 64a (preferably, the shroud extends directly around the stator 62b) is swept by the flow 36. The shroud 64a ensures heat exchange by heat conduction between the stator 62b and the flow 36.

[0156] exist Figure 7 and Figure 8 In the embodiment of the invention shown, the element 100 can then be located, for example, on the shroud 64 a and / or on the bladed straightener 174 .

[0157] Figure 9 Another alternative embodiment of the present invention is shown. The mounting area Z of the motor 62 is Figure 8 The installation area Z of the embodiment is similar.

[0158] Motor 62 is similar to Figure 8 The motor is a motor having stator 62b with cover C separated from shield 64a. Other features of this variant embodiment are similar to those of Figure 8 Features of the embodiments in .

Claims

1. An aircraft turbine engine (10) comprising a gas generator (12) and a fan (14), the fan being arranged upstream of the gas generator (12) and configured to generate a gas inlet flow (F), a portion of which flows in a duct of the gas generator to form a primary flow (36), and another portion of which flows in a duct surrounding the gas generator (12) to form a secondary flow (38), the fan having a fan shaft connected to a first rotor of the gas generator via a mechanical reducer, the turbine engine (10) further comprising an electric motor (62) having an annular shape and coaxially mounted downstream of the fan (14) and upstream of the mechanical reducer, the electric motor comprising a second rotor surrounding the fan shaft and surrounded by a stator (62b), the stator being carried by an annular shroud (64, 64a) surrounding the stator and with no spacing between the annular shroud and the stator, wherein The annular shroud extends axially downstream of the fan, wherein the annular shroud is surrounded by a housing (40) of the gas generator (12), the housing and the annular shroud (64, 64a) defining a section of a flow duct and an inlet for the main flow (36), fixed blades (42, 68, 174) for straightening the main flow (36) extending in the section of the flow duct, the annular shroud (64, 64a) and / or the fixed blades (42, 68, 174) comprising elements configured to generate disturbances in the main flow (36) (100), wherein the annular shroud includes an outer annular surface extending around the motor and defining the section of the flow duct of the main flow, the outer annular surface including an upstream end portion, the upstream end portion surrounding the upstream end portion of the motor and located upstream of the inlet, the outer annular surface also including a downstream end portion surrounding the downstream end portion of the motor and located in the section of the flow duct, and at least a portion of the stationary blades are connected to the outer annular surface between the upstream end portion and the downstream end portion of the outer annular surface.

2. The turbine engine (10) according to claim 1, wherein: The element (100) is recessed or protruding on one or more surfaces (150) of the annular shroud (64, 64a) and / or the stationary vanes (42, 68, 174), one or more of the surfaces (150) being intended to be swept by the main flow (36).

3. The turbine engine (10) according to claim 2, wherein: One of the surfaces (150) or each of the surfaces (150) comprises a matrix of identical recessed elements (100) distributed in rows and columns.

4. The turbine engine (10) according to claim 3, wherein: The cross section of each of the elements (100) has a concave curved shape.

5. The turbine engine (10) according to claim 3 or 4, wherein: Each of the elements (100) has a width or dimension D between 2 mm and 30 mm and a depth P less than or equal to D.

6. The turbine engine (10) according to claim 2, wherein: One of the surfaces (150) or each of the surfaces (150) comprises a series of elements (100) shaped like elongated grooves (110) extending generally in the direction of flow of the main flow (36).

7. The turbine engine (10) according to claim 6, wherein: The grooves (110) are corrugated.

8. The turbine engine (10) according to claim 2, wherein: One of said surfaces (150) or each of said surfaces (150) comprises a series of protruding elements (100) formed by fins (120).

9. The turbine engine (10) according to claim 8, wherein: The fins (120) are triangular or in the shape of the Greek letter delta.

10. The turbine engine (10) according to claim 8 or 9, wherein: The fins (120) are movable or retractable to adjust disturbances in the main flow (36).

11. The turbine engine (10) according to any one of claims 2 to 4, wherein: Said element (100) comprises a plasma generating actuator (130) situated on one of said surfaces (150) or each of said surfaces intended to be swept by said main flow (36).

12. The turbine engine (10) according to claim 11, wherein: The plasma generating actuator (130) is fed by the motor (62).

13. The turbine engine (10) according to claim 11, wherein: The plasma generating actuators (130) are evenly distributed around the motor (62).

14. The turbine engine (10) according to any one of claims 1 to 4, wherein: The annular shroud (64, 64a) includes an inner annular surface surrounding a stator (62b) of the electric machine (62), wherein the outer annular surface extends around the inner annular surface.

15. The turbine engine (10) according to any one of claims 1 to 4, wherein: The element (100) is connected to the stator (62b) by one or more heat-conducting parts to ensure heat exchange by conduction.

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