Electrical connection of an electric machine in an aircraft turbine engine

Abstract

An aircraft turbine engine (10) comprises: - a gas generator (12), - a fan (14), and - an electric machine (70), the stator (70b) of which is connected to a power electronics circuit (78) by at least one electrically conductive rod (80) extending substantially radially with respect to the axis within an IGV (52a) forming a component of a vane angular segment (G2), the rod (80) being configured to be disassembled and removed from the turbine engine by disassembling and removing the segment.

Description

TECHNICAL FIELD

[0001] The application relates to an aircraft turbomachine equipped with an electric machine and to a method for maintaining such a turbomachine. BACKGROUND

[0002] The prior art notably includes documents FR-A1-2 842 565, FR-A1-2 896 537, FR-A1-2 922 265 and EP-A1-3 246 528, which describe turbomachines equipped with electric machines.

[0003] The aeronautical world is now raising many questions about the relevance of using hybrid engines for commercial aviation. The use of electrical energy is now considered not only to meet the functions of the aircraft, but also to electrify the functions of the turbomachine.

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

[0005] These architectures can notably be based on architectures of high-bypass ratio and reducer type, but also on multi-body architectures (or Figure 2 or Figure 3 ). In these architectures, the turbomachine 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 an aircraft turbomachine with an electric machine. We remember that an electric machine is an electromechanical device based on electromagnetism (for example making it possible to convert electrical energy into mechanical or electrical energy). This process is reversible and can be used to generate electricity.

[0007] Thus, depending on the end use of the machine, we use the following terms:

[0008] • electric generator, designating an electric machine producing electrical energy from mechanical energy,

[0009] • electric motor, electric machine for producing mechanical energy from electrical energy.

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

[0011] Integrating a high-power electric machine on a low-pressure body of a turbomachine, in particular of high-bypass ratio type, is very complex. Several mounting areas are possible, but the advantages and disadvantages of each mounting area are varied (mechanical integration of the machine, temperature resistance of the machine, accessibility of the machine, etc.).

[0012] One solution to this problem is to integrate the electric machine directly downstream of the fan of the turbo engine. However, one difficulty is the connection of the machine to the power electronic circuit, which is generally located at a distance from the machine.

[0013] In this context, the use of an electric power harness poses some technical problems. The harness of large diameter has a very large bending radius, which is not compatible with this environment. The integration of the harness requires a support to limit the transmission of vibrations to the surrounding components and the damage to the surrounding components.

[0014] The present invention proposes a solution to at least some of the problems discussed above. SUMMARY

[0015] The present invention proposes an aircraft turbo engine comprising:

[0016] - a gas generator having a longitudinal axis,

[0017] - a fan located at an upstream end of the gas generator and configured to rotate around said axis, and

[0018] - an electric machine of generally toroidal shape, coaxially mounted downstream of the fan, and comprising a rotor and a stator, the rotor being rotationally coupled to the fan,

[0019] the fan being configured to generate a primary airflow, a part of the primary airflow flowing into a main annular duct of the gas generator to form a primary flow, another part of the primary airflow flowing around the gas generator to form a secondary flow,

[0020] the main duct being delimited by a first annular enclosure coaxial with the gas generator and a second annular enclosure, the main duct being crossed by a tubular arm of an inlet casing located downstream of the IGVs and by the arms of the IGVs connecting the first and second enclosures,

[0021] the gas generator comprising a third annular enclosure coaxially surrounding the second enclosure, the second and third enclosures being connected together at their upstream end to form an annular splitter nose for separating the primary flow and the secondary flow,

[0022] the stator of the electric machine being connected to the power electronic circuit by at least one electrically conductive rod extending substantially radially with respect to the axis within one of the IGVs,

[0023] characterized in that the first enclosure and the second enclosure are segmented, each of the segments of the first enclosure being connected to one of the segments of the second enclosure by an IGV to form a vane-type angular segment, only a part of these segments comprising an IGV crossed by said at least one rod, the at least one rod being rigidly connected to the IGV and to the segment, and the at least one rod being configured to be disassembled and removed from the turbomachine by disassembling and removing the segment.

[0024] The present invention thus proposes a solution for the integration of an electric machine, the first advantage being linked to the fact that the integration zone of the machine is ideally directly downstream of the fan and thus upstream of the compressor(s), where the temperature is relatively low, thus optimal for the machine. The rotor of the machine is driven by the fan and thus at a relatively low speed, in particular in the case where the turbomachine comprises a reduction gear. Furthermore, the machine is positioned as close as possible to the airflow duct of the airflow and has a relatively large diameter, thus enabling to produce a significant power compared to the machines of the prior art.

[0025] Furthermore, the present invention provides a solution to the electrical connection problem of the machine in this environment. This connection is ensured by one or more rods, each of the rods extending through an IGV, i.e. as close as possible to the splitter nose of the primary and secondary flows of the turbomachine.

[0026] The rod and the vane-type segment are intended to be disassembled and removed together, thus fixed to each other and not disassemblable from each other, which has several advantages:

[0027] - the advantage of segmenting the enclosure is that the enclosure isolates the function of transmitting electrical energy from the machine to the power electronics circuit; the operator chooses to use a segment comprising an IGV crossed by a rod and which can be considered as a "conductive" (or electrically conductive) segment, or to use a segment comprising an IGV without a rod and which can be considered as a conventional segment;

[0028] - preferably, the rod is fully integrated into the IGV and is shaped to adapt as well as possible to the aerodynamic part of the vane, thus significantly reducing the main torque of the vane;

[0029] - integrating the rod into the IGV also makes it possible to significantly increase the stiffness of the IGV, which reduces the risk of vibrations due to excessive flexibility; the rod does not need to be particularly maintained in the IGV.

[0030] The turbomachine according to the invention can comprise one or more of the following characteristics, taken independently of each other or in combination with each other:

[0031] - the rod crosses the IGV without clearance,

[0032] - the rod comprises an electrically conductive core surrounded by an insulating sheath, the insulating sheath being embedded in the material of the IGV,

[0033] - the IGV through which the rod passes is solid, its material extending seamlessly from the sheath to the aerodynamic outer face of the IGV,

[0034] - the sheath extends radially outward beyond the second enclosure and away from the free end of the rod to free this end, and radially inward beyond the first enclosure and away from the opposite free end of the rod to free this end,

[0035] - the third enclosure is segmented and comprises segments releasably attached to the second enclosure, each of the segments being associated with a segment of the third enclosure,

[0036] - the rod is generally L-shaped, the first and second portions being substantially rectilinear and connected to each other by a junction located directly downstream of the splitter nose;

[0037] - the rod has a polygonal and constant cross section and can be twisted;

[0038] - the turbine engine comprises a nacelle shell surrounding the gas generator, and vanes called OGVs, the vanes also serving to connect the nacelle shell to the third annular enclosure;

[0039] - the nacelle shell defines a secondary flow duct around the secondary flow of the gas generator;

[0040] - the OGV arms are located downstream of the IGVs and are substantially in line with the tubular arms of the inlet casing;

[0041] - the second portion extends substantially in line with one of the OGVs;

[0042] - the gas generator comprises an annular flange for attachment to the OGVs, the annular flange being located between the second and third enclosures, and the annular flange comprising a notch for the passage of the second portion of the rod;

[0043] - the rod comprises a radially inner end for releasable attachment to an element for electrical connection to the stator, and a radially outer end for releasable attachment to a wiring harness for electrical connection to the electrical circuit;

[0044] - the electric machine is located upstream of the splitter nose;

[0045] - the stator of the electric machine is connected to the electrical power supply by a plurality of electrically conductive rods distributed uniformly around the axis,

[0046] - the electronic circuit;

[0047] - the IGV or each IGV through which the rod passes is oversized relative to the other IGVs;

[0048] - the electrical power circuit is located between the second and third enclosures; the wiring harness has a core, the transverse

[0049] the cross section of the rod is identical to the cross section of the body of the rod;

[0050] - the cross section of the rod, in particular the cross section of the body of the rod, is constant along the entire length of the rod; and

[0051] - the rod is rigid;

[0052] - the rod is soft and pliable, and resembles a length of wiring harness or cable.

[0053] The application also relates to a vane sector for a turbine engine as described above, the vane sector comprising:

[0054] - a sector of the first annular enclosure,

[0055] - a sector of the second annular enclosure,

[0056] - at least one IGV extending between the sectors and connecting them together,

[0057] - an electrically conductive, preferably rigid, rod passing through the IGV or one of the IGVs and not removable from the arm and sector.

[0058] The application also relates to a method for maintaining a turbine engine as described above, the method comprising the steps of:

[0059] a) dismounting and removing at least one portion of the third enclosure, in particular at the rod, and

[0060] b) dismounting and removing the sector fixed to the rod.

[0061] The method according to the application can comprise one or more of the following steps, taken individually or in combination with one another:

[0062] - during steps a) and b), maintaining in place a connecting vane called an OGV for connecting the nacelle casing to the third annular enclosure,

[0063] - between steps a) and b), separating the rod from at least one electrical connection wiring harness,

[0064] after step b), removing the electrical connection wiring harness, which extends parallel to the longitudinal axis and is removed by axial translation towards the downstream by the arrangement of one of the tubular arms passing through the inlet casing. Attached Figure Description

[0065] The invention will be better understood from the following description, taken with reference to the accompanying drawings, by way of non-limiting example, and further details, features, and advantages of the invention will become apparent, in which:

[0066] - Figure 1 This is a schematic diagram of the axial cross-section of an aircraft turbine engine with a high bypass ratio and a decelerator;

[0067] - Figure 2 This is a partial schematic half-view of the axial cross-section of an aircraft turbine engine equipped with an electric motor according to the present invention;

[0068] - Figure 3 Similar to Figure 2 It also shows an electrical connection rod for electrically connecting the stator of the machine to the power electronic circuit;

[0069] - Figure 4 yes Figure 3 A schematic perspective view of a portion of a turbine engine, with particular emphasis on the IGV, one of which has an electrical connecting rod passing through it;

[0070] - Figure 5 yes Figure 3 Another schematic perspective view of a part of the turbine engine, and in particular showing the path of the electrical connecting rod;

[0071] - Figure 6 yes Figure 3 A schematic perspective view showing a portion of the turbine engine partially pulled out, illustrating the IGV, one of which is used to pass through the electrical connection rod;

[0072] - Figure 7a to 7d yes Figure 3 The document provides a detailed view and illustrates the steps involved in maintaining a turbine engine.

[0073] - Figure 8 It is a schematic cross-sectional view of an electrical wiring harness, and

[0074] - Figure 9 This is a schematic cross-sectional view of an embodiment of the electrical connection rod. Detailed Implementation

[0075] First, refer to Figure 1 It schematically shows the turbofan engine 10 of the twin-body twin-stream aircraft.

[0076] The turbine engine 10 generally comprises a gas generator 12 upstream of which a fan 14 is arranged. The fan 14 is surrounded by a casing 16 which is surrounded by a nacelle 18 which surrounds and extends along a main part of the gas generator 12.

[0077] Here, the gas generator 12 comprises two main bodies, namely a low pressure body 12a or LP and a high pressure body 12b or HP. Each main body comprises a compressor and a turbine.

[0078] The terms "upstream" and "downstream" are considered in the main direction of flow of the gases in the turbine engine 10, this direction F being parallel to the longitudinal axis A of the turbine engine.

[0079] 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.

[0080] The fan 14 comprises a ring of blades 30 which is driven in rotation by a fan shaft 32 connected to the rotor of the low pressure body 12a through a reduction gear 33. The flow of gases (arrow F) passing through the fan is separated upstream of the gas generator 12 by a ring separator nose 34 into a radially inner ring flow, called primary flow 36, which flows in the main annular duct of the gas generator 12, and a radially outer ring flow, called secondary flow 38, which flows in a secondary annular duct between the gas generator 12 and the nacelle 18 and provides most of the thrust of the turbine engine.

[0081] The inlet casing 40 structurally connects the gas generator 12 to the casing 16 and to the nacelle 18. The inlet casing 40 comprises a ring of radially inner arms 42 which extend into the flow duct of the primary flow 36 and a ring of radially outer straightener vanes 44 (also called outer gear vanes (OGV)) which extend into the flow duct of the secondary flow 38.

[0082] The number of arms 42 is generally limited (less than ten) and is tubular and traversed by the ancillaries. These arms 42 have a structural role in that they make it possible to transmit forces between the bearing supports and the suspension. They also have a role of traversing the ancillaries, by straightening them, which makes it possible to traverse the ducts, thus limiting the aerodynamic losses in the ducts. They do not have a flow straightening function since they have no camber and are not numerous enough to perform this function.

[0083] The number of straightener vanes 44 (OGV) is generally greater than ten. Thanks to the specific number and curvature, the straightener vanes enable the air flow of the fan to be straightened. The straightener vanes also have a structural function, since they support the casing (fan casing) around the fan.

[0084] The air flow duct of the main flow 36 is also crossed by additional straightener vanes 52, also called inner gear vanes (IGV). The IGVs 52 are evenly distributed around the axis A and are located upstream of the inlet casing 40, more precisely upstream of the arms 42. These vanes enable the air flow from the fan 14 to be straightened as it enters the main duct. These vanes have no structural role. They are present in sufficient number (for example more than 10) and have a curvature that enables the air flow of the fan entering the main duct to be straightened.

[0085] The air flow duct of the main flow 36 is delimited by two coaxial annular enclosures, respectively an inner enclosure 37a and an outer enclosure 37b. In particular, the IGVs 52 and the arms 42 are connected to these enclosures 37a, 37b. The air flow duct of the secondary flow 38 is internally delimited by an annular enclosure 39 coaxial with the enclosures 37a, 37b and externally by the nacelle casing 16. The OGVs 44 are connected to the enclosures 37b, 39.

[0086] Each of the enclosures 37a, 37b, 39 can be formed by a plurality of adjacent walls or covers.

[0087] The rotor of the low-pressure body 12a and the fan 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 and an outer ring carried by a rolling bearing between an annular bearing support and a ring.

[0088] In a known manner, the reduction gear 33 is of the epicyclic gear type and comprises a sun gear centered on the axis A, a ring gear extending around the axis and planet gears meshing with the sun gear and the ring gear and carried by a planet carrier.

[0089] In the example shown, the ring gear is fixed and connected fixedly to the support 62 of the bearings 46, 48. The planet carrier is rotatable and coupled to the fan shaft 32. The sun gear of the reduction gear is coupled to the main shaft 58 of the low-pressure body by an inlet shaft 56.

[0090] The inlet shaft 56 is guided by the bearing 50 carried by a bearing support 60. The fan shaft 32 is guided by the bearings 46, 48.

[0091] The bearing supports 60, 62 extend around the axis A and are fixed parts connected to the stator, in particular to the inlet casing 40.

[0092] Figure 2 is Figure 1 a more detailed and larger scale view of a part of

[0093] The elements described with reference to Figure 1 are denoted by the same reference numerals. Figure 2 In particular,

[0094] The region Z between the fan disc 32a and the reduction gear 33 is shown, in which the electric machine 70 is mounted. In Figure 2 only one support 33a of the ring gear of the reduction gear 33 is visible in Figure 2 which is connected, for example, to the inlet casing 40 or to the bearing support 62.

[0095] Figure 2 The cross section in the drawing of Figure 3 passes through one of the solid IGVs 52. However, as will be described in more detail below, at least one or some of the IGVs 52 are special and denoted by the reference 52a. This type of IGV 52a is shown in cross section in

[0096] As mentioned above, the cross section passes through the OGV 44 and through the arms 42, which are tubular arms for the passage of the adjuvant. Each arm 42 comprises an upstream edge 42a and a downstream edge 42d, which are respectively the leading edge and the trailing edge of the main flow 36.

[0097] Each arm 42 comprises an inner cavity 42c, which is closed radially outwards by a wall 44a of the OGV 44. This wall 44a is formed integrally with the OGV 44 and is attached respectively to an upstream annular flange 43a and to a downstream annular flange 43b of the inlet casing 40. The cavity 42c is isolated from the adjuvant by a wall 42b.

[0098] The inner cavity 42c of each arm 42 is closed radially inwards by an annular wall 40a of the inlet casing 40. At the upstream end of this wall 40a, the inlet casing 40 comprises a radially inner annular attachment flange 40b for attaching the bearing support 62. At the downstream end of the wall 40a, the inlet casing 40 comprises a radially inner annular attachment flange 40c for attaching, for example, an annular slot for recovering the oil ejected by the reduction gear 33 by centrifugation.

[0099] Figure 1The visible decelerator 33 and the bearings 46, 48, 50 are located in an annular lubrication enclosure E, which is delimited upstream by the bearing support 62 and at least one non-visible sealing joint, and downstream by the bearing support 60 and at least one non-visible sealing joint. The outer periphery of the enclosure E is in particular sealed by the wall 40a.

[0100] Figure 2 It is shown that the above-mentioned enclosure 37a is formed by a plurality of successive annular walls, such as the wall 40a, and an annular virole 64 located upstream of the wall 40a and connected to the inner periphery of the IGVs 52, 52a.

[0101] The enclosure 37b is formed by a plurality of successive annular walls and in particular an annular virole 66 located upstream of the inlet casing 40. This virole 66 extends around the virole 64 and is connected to the outer periphery of the IGVs 52, 52a.

[0102] The enclosure 39 is formed by a plurality of successive annular walls, such as the wall 44a, and an annular virole 68 located upstream of the wall 44a. This virole 68 extends around the virole 66 and the upstream ends of the viroles 66, 68 are connected together to form the splitter nose 34.

[0103] As mentioned above, the electric machine 70 is located in an annular zone Z, which is delimited upstream by the fan 14 and in particular the disc 32a connecting the fan blades 30 to the fan shaft, and downstream by the bearing support 62.

[0104] The machine 70 is of generally annular shape and comprises a rotor 70a and a stator 70b. The rotor 70a has a generally annular shape extending around the axis A and is carried by a support element 72 which itself has a generally annular shape.

[0105] In the example shown, the support element 72 comprises a cylindrical wall 72a which is surrounded by the rotor 70a and attached to the inner periphery of the rotor. The upstream end of this wall 72a is connected to a radially inner annular attachment flange 72b for attachment to the fan disc 32a and to an outer annular rim 72c.

[0106] The rim 72c comprises an inner cylindrical surface 72d which bears on an outer cylindrical surface of the fan 14 to ensure centring of the rotor 70a. The rim 72c also comprises an outer annular scraping portion 72e of a labyrinth-type sealing joint.

[0107] The stator 70b is also of generally annular shape and is carried by an annular support element 74.

[0108] The element 74 comprises an outer annular surface 74a which, internally, defines a flow duct for the airflow F between the fan 14 and the splitter nose 34. The element 74 is attached to the outer periphery of the stator 70b and comprises an upstream end which cooperates with the aforementioned scraping portion 72e, for example by means of an abradable annular coating.

[0109] The downstream end of the element 74 is axially aligned with the collar 64, the upstream circumferential edge of which is axially engaged in an annular valley 74b of the element 74. This valley 74b is oriented axially downstream. The engagement of the upstream edge of the collar 64 in the valley 74b of the element 74 ensures an overlap, thus avoiding a step in the duct which would disturb the airflow F.

[0110] The downstream end of the element 74 also comprises an annular attachment flange 76 for attachment to the bearing support 62 or to the inlet casing 40. The axial cross section of this flange 76 is generally U-shaped, the opening of which is oriented radially outwards. This flange 76 thus defines an annular space X for the electrical connections of the stator 70b, as will be described in particular with reference to Figure 3 The flange 76 is attached to the flange of the bearing support 62 and to the flange 40b of the inlet casing by screws in the example shown.

[0111] The element 74 can be formed in one piece or by two annular and coaxial parts mounted around each other.

[0112] One of the particularities of this mounting is that the electric machine 70, and in particular the stator 70b of the electric machine, is as close as possible to the main flow F after passing through the fan 14. This makes it possible to have an electric machine of large diameter, thus with a higher potential power than the techniques proposed to date, and to have a machine cooled by the airflow F. Advantageously, the thermal rejection of the electric machine 70 is dissipated thanks to this cooling.

[0113] To this end, the surface 74a swept by the airflow F preferably has an aerodynamic profile, as illustrated. The element 74 ensures heat exchange by thermal conduction between the stator 70b and the airflow F.

[0114] The stator 70b is connected by electrical connection means to a power electronic circuit 78 which is located between the two enclosures 37b, 39, thus around the gas generator 12.

[0115] Figure 3 to 7d An embodiment of these electrical connection means is illustrated, comprising at least one (preferably rigid) rod 80.

[0116] Although one or more electrical harnesses 82c, 82d can additionally be used for the electrical connection of the stator 70b, the use of at least one rod 80 provides a number of advantages.

[0117] In a preferred embodiment of the application, the stator 70b is connected by a first electrical harness 82c to one end of the rod 80, the opposite end of the rod being connected to the electrical circuit 78 by a second electrical harness 82d. Figure 3 ) In this case, the cross section of the core 82a of each harness 82c, 82d is preferably identical or close to the cross section of the body 80a of the rod 80. Figure 8 and Figure 9 The cross section of the rod 80, and in particular of the body 80a of the rod, is preferably constant over the entire length of the rod.

[0118] The rod 80, which can be seen almost in its entirety in Figure 6 , is shaped so as to extend from the zone Z, in particular the space X, to the space Y located between the enclosures 37b, 39, just downstream of the diverter nose 34 and radially inside the collar 68.

[0119] The rod 80 can have a complex overall shape, for example L-shaped, S-shaped, Z-shaped, etc. In the example shown, the rod extends in a plane PI that passes through the axis A and corresponds to the cross section in Figure 3 .

[0120] The rod 80 comprises an electrically conductive core 80a surrounded by an insulating sheath 80b (see Figure 8 and Figure 9 .

[0121] The rod 80 comprises an upstream end 84a and a downstream end 84b, respectively, which are exposed, i.e. not covered by the sheath 80b, so that the rod 80 can be connected to the harnesses 82c, 82d Figure 4 to 6 .

[0122] The sheath 80 extends radially outward beyond the collar 66 and away from the free end 84b of the rod, so as to free this end, and radially inward beyond the collar 64 and away from the opposite free end 84a of the rod, so as to free this end.

[0123] Each of the ends 84a, 84b comprises a hole 86 for mounting a bolt 88 (screw and nut, or even a washer). This bolt 88 is used to attach the ends 84a, 84b of the rod 80 to the corresponding harnesses 82c, 82d, preferably by means of a lug 90. The lug 90 is connected to one end of the harness 82c, 82d and comprises a plate intended to be applied to the corresponding end 84a, 84b and tightened and attached to this end by means of the bolt 88 Figure 4 to 6 .

[0124] The present invention proposes a specific path for the rods 80 from the space X to the space Y, more specifically, a specific path between the wire bundles 82c, 82d. Note that in practice, the stator 70b can be connected to the circuit 78 by a plurality of rods 80. Then, these rods 80 are preferably evenly distributed around the axis A, and each rod is connected to the stator 70b and to the circuit 78 by a wire bundle 82c, 82d. The following description of the rods 80 therefore applies to each electrically connecting rod 80 that electrically connects the stator 70b of the electric machine 70 to the power electronic circuit 78.

[0125] In the embodiment shown in the figures, the rods 80 extend through one of the IGVs 52a.

[0126] More specifically, the rods 80 are generally L-shaped and comprise a first portion 80c that extends substantially radially within the IGV 52 with respect to the axis A and a second portion 80d that extends substantially parallel to the axis A between the enclosures 37b, 39 and just upstream of one of the OGVs 44.

[0127] The portions 80c, 80d are substantially rectilinear and are connected to each other by a curved junction 80e located just downstream of the splitter nose 34, between the collars 66, 68. To some extent, as in the example shown, the IGV 52 can be inclined from upstream to downstream outwardly, the first portion 80c can have a similar inclination.

[0128] The portion 80c is longer than the portion 80d.

[0129] It can be seen from Figure 3 that the end 84a is located in the space X mentioned above and is connected by the bolt 88 to the wire bundle 82c in this space X. It will therefore be understood that when the rod 80 extends through the IGV 52a, the rod, in particular the portion 80c of the rod, passes through the collars 64, 66.

[0130] One of the particularities of the present invention is that each of the enclosures 37a, 37b is sectioned at the IGVs 52, 52a. The collars 64, 66 are therefore sectioned, and each section of the collar 64 is connected to a section of the collar 66 by one or more IGVs 52, 52a.

[0131] In the example shown, Figure 4 to 6 each collar section 64 is connected to a collar section 66 by 3 or 4 IGVs. The assembly formed by the collar section 64, the collar section 66 and the IGVs forms a vane segment.

[0132] The turbine engine 10 comprises a plurality of segments distributed around the axis A and arranged end-to-end along a circumference. The segments are of two types. The segments of a first type, marked G1, comprise only IGVs 52, in this case the number is 4, while the segments of a second type, marked G2, comprise IGVs 52a or even IGVs 52, the number is 2. It will thus be understood that each segment G2 is also associated with a stem 80 passing through the IGV 52a.

[0133] Due to the difference in the number of IGVs between the segment types G1, G2, the segments can have different sizes in the circumferential direction. Thus, in the example shown, the segments G1 have a larger circumferential size than the segments G2.

[0134] Another particularity of the invention is that the stem 80 cannot be separated or detached from the segment G2 of the stem, and vice versa. This means that the stem 80 can only be detached and removed from the turbine engine together with the segment G2 of the stem.

[0135] The ferrule 68 is also segmented and comprises releasably attached segments. Each of the segments G1, G2 is associated with a ferrule segment 68.

[0136] In particular, Figure 6 It is shown that the material of the IGV 52a is firmly bonded to the stem 80 and overlaps the sheath 80b of the stem without a gap. Thus, the sheath 80b is embedded in the material of the IGV 52a. Thus, the IGV 52a through which the stem 80 passes is solid, as its material extends seamlessly from the sheath 80b to the aerodynamic outer face of the IGV, which can form the soffit and the intrados, respectively.

[0137] It can be seen from Figure 4 to 6 that each IGV 52a for the passage of a stem 80 is of large size. It will be understood that the number of large-sized IGVs 52a will depend on the number of electrical connection stems 80 for electrically connecting the machine 70 to the electrical circuit 78, each stem 80 passing through one of these large-sized arms.

[0138] It can be seen from Figure 4 to 6 that the portion 80d of the stem 80 is aligned with the notches 92 in the flanges 43a, 43b. These are axial notches 92 formed at the outer periphery of the flanges 43a, 43b for the attachment of the OGVs 44 and shaped so that the wiring harness 82d connected to the stem 80 can extend through these notches 92 without interfering with the attachment of the OGVs 44 to the flanges 43a, 43b. Thus, the notches 92 are arranged so that the wiring harness 82d extends between two adjacent OGVs 44.

[0139] Figure 7a to 7d The steps of a maintenance method for the turbine engine 10 are shown.

[0140] In accordance with the order of the steps illustrated, these steps make it possible to dismount the rod 80. It will be understood that repeating these steps in the reverse order is sufficient to carry out the assembly or reassembly of the rod 80. Figure 7a to 7d

[0141] In a first step illustrated in Figure 7a and Figure 7b , at least one portion of the third envelope 39, in particular at the rod 80, is dismounted and removed. This involves dismounting and removing the segment (G1 ) of the collar 68. Figure 7a and Figure 7b

[0142] Then, a further step is to disengage the ends 84a, 84b of the rod 80 from the harnesses 82c, 82d. As illustrated in Figure 7b and Figure 7c , the rod 80 is then dismounted and can be removed with the segment G2 of the rod, for example by upstream axial translation.

[0143] Finally, Figure 7d a last step is illustrated in which the harness 82d, which is no longer connected to the rod 80, is removed by downstream axial translation through the notches 92 in the arms 43a, 43b.

[0144] Figure 8 A cross-section of the electrical harness 82 is illustrated, which is substantially circular and comprises a conductive core 82a formed of a strand of electrical wire and an insulating outer sheath 82b. Figure 9 An example of an embodiment of the rod 80 is illustrated, which comprises a conductive body 80a, preferably having a polygonal shape in cross-section, and for example rectangular. The rod 80 also comprises an insulating outer sheath 80b.

[0145] Some advantages of the invention have already been described above. Other advantages of the invention include:

[0146] - the path of the rod is compatible with all the oil additives circulating in the arms of the inlet housing. In addition, the wall installed in the arms of the inlet housing isolates the rod from the oil additives, which limits the risk of fire;

[0147] - modularity, designed to optimize / facilitate the assembly and disassembly of the "driver" segment, without having to dismount the OGV;

[0148] - unlike the harness, the rod 80 makes it possible to have a very short bending radius, which is necessary in the environment in question; this makes it possible to limit the thickness of the splitter nose 34 to a thickness close to that of the rod 80;

[0149] ​​- when the rod 80 is rigid, there is no risk of vibrations due to too much flexibility, so no specific support is needed in the arms of the inlet casing 40;

[0150] - the path described above is compatible with all the oil additives circulating in the arms of the inlet casing 40; moreover, the walls of the inlet casing 40, in particular the walls 40a and 42b, isolate the rod 80 from these oil additives, which limits the risk of fire; and

[0151] - the modularity created by the ease of assembly / disassembly of the rod 80 by removing only one section of the turbine engine.

[0152] The present application can be applied to any turbine engine equipped with an electric machine upstream of a structural casing, such as an inlet casing or other.

Claims

1. An aircraft turboreactor (10) comprising: - a gas generator (12) having a longitudinal axis (A), - a fan (14) located at an upstream end of the gas generator and configured to rotate about the axis, and - a generally annular electric machine (70) coaxially mounted downstream of the fan and comprising a rotor (70a) and a stator (70b), the rotor being rotationally coupled to the fan, the fan being configured to generate a primary airflow (F), a portion of which flows into a main annular duct of the gas generator to form a primary flow (36), another portion of which flows around the gas generator to form a secondary flow (38), the main annular duct being delimited by a first annular enclosure (37a) and a second annular enclosure (37b) coaxial with the gas generator, the main annular duct being crossed by vanes called internal gear vanes, also called IGVs, connecting the first annular enclosure and the second annular enclosure, and by a tubular arm (42) of an inlet casing located downstream of the IGVs, the gas generator comprising a third annular enclosure (39) coaxially surrounding the second annular enclosure, the second annular enclosure (37b) and the third annular enclosure (39) being connected together at an upstream end of the second and third annular enclosures to form an annular splitter nose (34) for separating the primary flow (36) and the secondary flow (38), the stator (70b) of the electric machine (70) being connected to a power electronics circuit (78) by at least one electrically conductive rod (80) extending substantially radially with respect to the axis within one of the IGVs, characterized in that the first annular enclosure (37a) and the second annular enclosure (37b) are segmented, each of the segments of the first annular enclosure (37a) being connected to one of the segments of the second annular enclosure (37b) by an IGV to form a vaned angular segment, only a portion (G2) of these segments comprising an IGV crossed by the at least one electrically conductive rod (80), the at least one rod being rigidly connected to the IGV and to the segment, and the at least one rod being configured to be disassembled and removed from the turboreactor by disassembling and removing the segment.

2. The turbine engine (10) of claim 1, wherein, The electrically conductive rod (80) crosses the IGV without clearance.

3. The turbine engine (10) of claim 2, wherein, The electrically conductive rod (80) comprises an electrically conductive core (80a) surrounded by an insulating sheath (80b) embedded in the material of the IGV.

4. The turbine engine (10) of claim 3, wherein, The IGV crossed by the electrically conductive rod (80) is solid, the material of the IGV crossed by the electrically conductive rod (80) extending seamlessly from the sheath (80b) to the aerodynamic outer face of the IGV.

5. The turbine engine (10) of claim 3 or 4, wherein, The sheath (80b) extends radially outward beyond the second annular enclosure (37b) and away from a free end of the electrically conductive rod (80) to free the end, and radially inward beyond the first annular enclosure (37a) and away from an opposite free end of the electrically conductive rod to free the end.

6. The turbine engine (10) of any one of claims 1 to 4, wherein, The third annular enclosure (39) is segmented and comprises segments releasably attached to the second annular enclosure (37b), each of the segments being associated with a segment of the third annular enclosure.

7. The turbine engine (10) of any one of claims 1 to 4, wherein, The electrically conductive rod (80) comprises a radially inner end (84a) for releasable attachment to an element for electrical connection to the stator (70b) and a radially outer end (84b) for releasable attachment to a wiring harness (82b) for electrical connection to the electrical circuit (78).

8. The turbine engine (10) of any one of claims 1 to 4, wherein, The IGV through which the electrically conductive rod (80) passes is oversized relative to the other IGVs.

9. A vane segment for a turbine engine (10) according to any one of the preceding claims, the segment comprising: - a first annular enclosure segment, - a second annular enclosure segment, - at least one IGV extending between and connecting together the segments, - an electrically conductive rod (80) passing through the at least one IGV and not removable from the arm and the segment.

10. A method for maintaining a turbine engine (10) according to any one of claims 1 to 8, the method comprising the steps of: a) disassembling and removing at least one portion of the third annular enclosure (39), and b) disassembling and removing a segment fixed to an electrically conductive rod (80).

11. The method according to the preceding claim, wherein, The method comprises one or more of the following steps: - during the steps a) and b), maintaining in place a connecting vane called an outer gear vane (44), also called an OGV, for connecting a nacelle casing (16) to the third annular enclosure (39), - between the steps a) and b), detaching the electrically conductive rod (80) from at least one electrical connection harness, - after the step b), removing an electrical connection harness (82d) extending parallel to the longitudinal axis (A) and removed by axial translation towards downstream by arrangement passing through one of the tubular arms (42) of the inlet casing.

12. The method of claim 10, wherein, The step a) comprises disassembling and removing at least one portion of the third annular enclosure (39) at the electrically conductive rod (80).

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