Turbojet engine equipped with an electrical machine comprising several electrical modules of different diameters

Abstract

The invention relates to a turbojet engine (1) extending along a longitudinal axis (AX), and comprising an electrical machine (52), characterized in that: – this electrical machine (52) comprises several adjacent modules (M1, M2) along the longitudinal axis (AX), each module (M1, M2) comprising a portion of a concentric rotor (R1, R2) and a portion of a concentric stator (S1, S2) jointly defining an air gap (E1, E2) of revolution; – the air gaps (E1, E2) of two adjacent modules (M1, M2) have different diameters; – the portions of rotors (R1, R2) and are part of a rotor (41) of the turbojet engine (1) which is rotationally linked to a low-pressure body (9) of this turbojet engine (1); – Each stator segment (S1, S2) is equipped with windings (B1, B2); the windings (B1, B2) of the different stator segments (S1, S2) are wired together. See Figure 2 for abbreviations.

Description

Title of the invention: Turbojet engine equipped with an electrical machine comprising several electrical modules of different diameters technical field

[0001] The invention relates to the integration of an electrical machine, which may be for example an alternator or a motor, into a turbojet engine. PREVIOUS STATE OF THE ART

[0002] In light of the recent growth of electrically powered systems, the aeronautical field is studying the integration of one or more electric machines within a turbojet engine to design a hybrid engine solution. Such a solution aims to use the fossil fuel energy and electrical energy to drive the engine's propulsion system and to electrically power certain functions of the engine and / or the aircraft it equips.

[0003] In practice, such integration encounters numerous problems. The compact arrangement of components within existing motors leaves little room for adding an electric machine. The maintenance of the electric machine requires ensuring that it is easily accessible, meaning that it is possible to work on it without having to dismantle an excessive number of components.

[0004] Various integration solutions have been considered, but they require either significantly modifying the general structure of the motor, or reducing the dimensions of the electrical machine that can be integrated, which in turn reduces the electrical power that can be carried.

[0005] In this context, the aim of the invention is to provide a solution enabling the integration of an electric machine into a motor while minimizing the modifications to be made to this motor. Description of the invention

[0006] To this end, the invention relates to a turbojet engine extending along a longitudinal axis, and comprising an electrical machine, characterized in that:

[0007] - this electrical machine comprises several adjacent modules along the axis longitudinal, each module comprising a portion of concentric electric rotor and a portion of concentric electric stator jointly defining an air gap of revolution;

[0008] - the air gaps of two adjacent modules have different diameters;

[0009] - the rotor portions are part of a rotor linked in rotation to a low-pressure body of the turbojet;

[0010] - each portion of the electric stator is provided with windings, and the windings of different portions of the stator being electrically connected to each other within the stator.

[0011] Thanks to the invention, the different diameters of the rotor sections allow the electric machine to optimally occupy a complex internal space, such as a conical or other shape of the turbojet, in a manner optimized to produce or receive maximum electrical power. The invention thus makes optimal use of the available space for the integration of an electric machine.

[0012] The invention also relates to a turbojet engine as defined above, comprising:

[0013] - an inlet casing extending upstream of a low-pressure compressor of the turbojet;

[0014] - a fixed cone carried by the inlet housing and extending upstream of this housing entry;

[0015] and in which:

[0016] - the electrical stator portions are carried by the fixed cone;

[0017] - the electric rotor portions extend inside the fixed cone by being surrounded by the stator portions.

[0018] The invention also relates to a turbojet thus defined, in which the rotor has a downstream end engaged in a tubular part of the low-pressure body and being rotationally linked to the low-pressure body by a grooved connection.

[0019] The invention also relates to a turbojet thus defined, comprising a tie rod carried by a cover screwed into a thread in the tubular part, in which the downstream end of the rotor has a bottom through which this tie rod passes, and in which the downstream end of the rotor is held axially by a nut screwed onto the tie rod.

[0020] The invention also relates to a turbojet thus defined, in which the fixed cone has studs by which it is fixed to the inlet casing, each stud passing through an upstream wall of the inlet casing.

[0021] The invention also relates to a turbojet engine as defined above, comprising:

[0022] - an intermediate casing extending downstream of a low-pressure compressor of this turbojet

[0023] - a median bearing supported by the intermediate housing and extending into a region radially internal to the low-pressure compressor to support an upstream part of the low-pressure body;

[0024] and in which:

[0025] - the electrical stator portions are carried by the intermediate housing;

[0026] - the electrical rotor portions surround the stator portions and are supported by a rotating body rigidly linked to the low-pressure body.

[0027] The invention also relates to a turbojet thus defined, in which the electrical stator portions are part of a stator carrying at least one low-pressure body rotation guide bearing.

[0028] The invention also relates to a turbojet thus defined, comprising at least three modules, delimiting three air gaps of revolution, these air gaps having different diameters which are increasing from upstream to downstream of the turbojet.

[0029] The invention also relates to a turbojet thus defined, in which the stator and the housing to which this stator is fixed are equipped with pin electrical connectors for connecting the stator windings to the turbojet.

[0030] The invention also relates to a turbojet thus defined, in which the stator has oil circulation channels, and in which the stator and the housing to which this stator is fixed are equipped with quick connectors for connecting the stator channels to the turbojet. Brief description of the drawings

[0031] Fig. 1 is a longitudinal cross-sectional view of a turbojet engine according to the invention;

[0032] Figure [Fig. 2] is a partial longitudinal sectional view showing the fixed cone of a turbojet according to a first embodiment of the invention;

[0033] The [Fig.3] is a partial longitudinal cross-sectional view showing the attachment of the downstream part of the fixed cone to the inlet housing in a reactor according to the first embodiment of the invention;

[0034] Fig. 4 is a longitudinal sectional view showing the integration of an electrical machine at the level of an intermediate turbojet casing according to the second embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0035] In [Fig.1], a turbojet 1 extending along an axis of rotation AX has upstream AM an inlet sleeve through which air is admitted to pass through a low-pressure compressor 2 before being split into a central primary flow Fl and a secondary flow F2 surrounding the primary flow.

[0036] These flows circulate in the turbojet 1 from upstream AM to downstream AV, this turbojet being delimited externally by a hull 3 which externally delimits the secondary flow F2.

[0037] The primary flow is then compressed in a high-pressure compressor 4 before entering a combustion chamber 5, after which it is expanded through a high-pressure turbine 6 and a low-pressure turbine 7 before being discharged to the rear. The secondary flow, on the other hand, is directed directly to the rear.

[0038] As can be seen in [Fig. 1], the low-pressure compressor 2 and the low-pressure turbine 7 comprise movable blades supported by a rotating assembly constituting a low pressure body 9. Similarly, the high pressure compressor 4 and the high pressure turbine 6 have movable blades carried by the same high pressure body 11, which surrounds the low pressure body while being independent in rotation of it, these two bodies rotating around a longitudinal axis AX.

[0039] This engine includes upstream of the low-pressure compressor 2 an inlet housing 12, comprising radial arms identified by 13 on the [Fig.2], by which it is secured to structural elements of the hull 3. An upstream bearing 14 mounted in this inlet housing 12 carries in rotation an upstream part of the low-pressure body 9.

[0040] It also includes an exhaust casing 16 located downstream of the low-pressure turbine and secured to the hull 3 by radial arms, in which is mounted a downstream bearing 17 which rotates a downstream part of the low-pressure body.

[0041] Similarly, an intermediate housing 18 (inter-compressor housing) is located between the compressors and secured to the hull 3 by other radial arms, and a median bearing 19 is mounted in this intermediate housing 18 to rotate a median portion of the low-pressure housing. Another bearing 21 mounted in this intermediate housing 18 rotates an upstream end of the high-pressure housing 11. The downstream end of the high-pressure housing 11 is rotated by an additional inter-shaft bearing 22 which is interposed between the low-pressure housing 9 and the high-pressure housing 11. First method of implementation

[0042] This inlet housing 12 is extended upstream by a fixed cone 23, directing the incoming flow around the central part comprising the high and low pressure bodies, minimizing induced aerodynamic losses.

[0043] As can be seen more clearly in [Fig.2], the bearing 14 which extends in the inlet housing 12 to which it is fixed comprises structural elements 24 carrying an outer ring of a ball bearing 26 whose inner ring surrounds and encloses a tubular part 27 of an upstream portion 28 of the low pressure body 9, to guide in rotation and maintain the upstream portion 28 of the low pressure body 9.

[0044] This tubular part 27 advantageously forms part of the disc carrying the first blades of the low pressure compressor 2, that is to say the first compressor disc, this low pressure compressor being similar here to a blower.

[0045] The upstream portion 28 corresponds for example to an extension of the low pressure body disc 9 which carries the first row of movable blades of the low pressure compressor 2 of the engine.

[0046] As can be seen more clearly in [Fig. 3], a sealing barrier 29 located upstream of the bearing 26 comprises an attached ring 31 surrounding the tubular part 27 and being rigidly attached to it, cooperating with a seal 32 of which the inner face runs along the outer face of the crown 31 to ensure controlled sealing upstream of the bearing 26 carried by the bearing 14.

[0047] An internal cover 34 is screwed into a threaded hole 36 formed in the internal face of the part 27, being located along the axis AX downstream of the bearing 26, to close this tubular part 27.

[0048] This inner cover 34 includes a threaded rod forming a tie rod 37 extending from its upstream face to extend upstream inside the part 27. This tie rod 37 has a flat 38 at its free end, allowing a tool to be engaged on this end to rotate the tie rod with the cover in order to screw it into the threaded hole 36 to mount the cover in the tubular part 27.

[0049] The tubular part 27 receives a downstream end 39 of an electric machine rotor 41. This downstream end 39 has a tubular shape, with an external diameter close to the internal diameter of the part 27, and has a bottom 42 provided with a central hole suitable for receiving the tie rod 37.

[0050] When in place in part 27, the downstream end 39 is immobilized in rotation relative to part 27 by a grooved connection 43 having external grooves of the end 39 engaging longitudinally in internal grooves of part 27.

[0051] In addition, a stud 44 passes through a corresponding through hole in the bottom 42 and engages in a blind hole in the lid, to also block the lid from rotating relative to the end 39.

[0052] The axial locking of the rotor 41 relative to the part 27 is ensured by engaging a nut 46 around the threaded rod 37, and tightening it, so that it is immobilized relative to the cover, and thereby relative to the part 27 of the low-pressure body 9. The nut 46 is advantageously of the self-locking type.

[0053] As seen in [Fig.2], the rotor 41 which extends upstream of the bearing 14 comprises a first portion of electric rotor RI extended axially by a second portion of electric rotor R2 of larger diameter than the first, this second portion R2 being extended axially by the downstream end 39 by which this rotor 41 is rigidly attached to the tubular part 27.

[0054] More particularly, this rotor 41 is formed of a tubular body 47 carrying on its external face first magnets Al at the level of the first portion of electric rotor RI, and second magnets A2 at the level of the second portion of electric rotor R2.

[0055] This rotor 41 is capped by the fixed cone 23 which has a sleeve 48 flared downstream, incorporating a stator 49, and a cover 51 closing the upstream end of this sleeve 48. The stator 49 has a first stator portion SI, which is closed upstream by the cover 51, and which is extended downstream by a second portion of stator S2 rigidly attached to the inlet housing 12.

[0056] The first stator portion SI surrounds the first rotor portion RI, defining with it a first air gap E1 having a shape of revolution, to form a first module M1 of the electric machine. Similarly, the second stator portion S2 surrounds the second rotor portion R2, defining with it a second air gap E2 of revolution, to constitute a second module M2 of the electric machine.

[0057] The first stator portion SI and the second stator portion S2 have windings Bl, B2 which are wired in a common way, i.e. the windings of the different modules are electrically connected to each other in the stator 49. The modules M1 and M2 thus together form a single electrical machine 52 having for example a single set of electrical terminals carried by the stator.

[0058] As can be seen in [Fig. 2], the tubular body 47 has a larger diameter at the second rotor portion R2 than at the first rotor portion RL. Similarly, the internal diameter of the sleeve 48 which incorporates the stator 49 is larger at the second rotor portion R2 than at the first rotor portion RL.

[0059] The diameter d2 of the air gap E2 is thus greater than the diameter dl of the air gap El, so that, generally speaking, the diameter of the module M2 is greater than that of the module ML. The air gaps El and E2 therefore have diameters that increase from upstream to downstream along the axis AX. This makes it possible to best utilize the internal space delimited by the fixed cone 23 in order to maximize the power of the electric machine, while also allowing the fixed cone 23 to be mounted and dismounted when the rotor 41 is in place.

[0060] The cone 23 which corresponds to the stator of the electric machine is fixed to an upstream face of the input housing 12 by several studs 53 uniformly distributed at the level of the downstream edge 56 of the sleeve 48 from which these studs 53 protrude axially.

[0061] Each stud 53 passes through a corresponding hole formed in an upstream wall 57 of the inlet housing 12 against which the downstream edge 56 of the sleeve 48 is applied. A nut 54 is screwed and tightened onto the end of each stud 53 to clamp the wall 57 between this nut 54 and the edge 56.

[0062] Under these conditions, the stator of the electric machine, i.e. the fixed cone 23, can be completely disassembled by unscrewing the nuts 54, and then extracted by axially moving it away from the input housing.

[0063] Similarly, the rotor 41 of the electric machine can then be removed by loosening and removing the nut 46 from the tie rod 37, before extracting the rotor by sliding it axially in the part 27 to move it away from the input housing 12.

[0064] The arrangement according to the invention thus makes it easy to intervene on the electric machine for a maintenance operation, since it allows the stator and rotor to be disassembled independently, without disassembling any other part of the motor: the electric machine constitutes an assembly substantially independent of the rest of the motor in terms of maintenance.

[0065] In addition, it remains possible to access the internal region of the low-pressure body, because the cover carrying the threaded rod 37 is removable, so that it can be removed to pass a tool inside the low-pressure body, through the tubular part 27.

[0066] Moreover, in the example of figures 2 and 3 the electric machine comprises two modules, but it could comprise three, four or any other number. 2nd method of implementation

[0067] According to a variant shown in [Fig. 4], the machine is integrated into a motor without a fixed cone, comprising a blower. In this case, the electric machine 52 is integrated into the radially internal region of the low-pressure compressor 2, in which the central bearing 19 is installed, held by the intermediate housing 18 to which it is rigidly attached, to rotate an upstream portion of the low-pressure body 9. This central bearing 19 here comprises a ball bearing 26 located upstream of it and a roller bearing 58 located downstream of the bearing 26.

[0068] This bearing 19 includes a hollow stator 49 rigidly attached to the housing 18, this stator 49 extending upstream in the radially internal space of the compressor 2. This stator 49 carries the outer rings of the two bearings 26 and 58 which guide the low-pressure body 9 in rotation.

[0069] The stator 49 is surrounded by a rotating body 59 rigidly attached to the upstream end of the low-pressure body 9 by a rigid connection 61. This rotating body 59 carries blower blades 62 at its upstream end, and the moving blades 63 of the low-pressure compressor 2 in its central portion which extends around the stator 49. The compressor 2 also includes fixed blades which are carried by a low-pressure stator 64 whose downstream end is rigidly attached to the housing 18.

[0070] As can be seen in [Fig. 4], the stator 49 comprises a first electrical stator portion S1 extended axially downstream by a second electrical stator portion S2 of larger diameter than the first. This second portion S2 is itself extended downstream by a third electrical stator portion S3 having an even larger diameter. This stator 49, which is rigidly attached to the housing 18 at the downstream end of its third stator portion S3, thus constitutes both a bearing support and an electrical stator.

[0071] The first stator portion SI, the second stator portion S2, and the third stator portion S3 comprise electrical windings identified respectively by B1, B2 and B3.

[0072] This stator 49 is surrounded by the rotating body 59 which includes a rotor 41 comprising a first portion of electric rotor RI extended downstream by a second portion of electric rotor R2 which is itself extended downstream by a third portion of electric rotor R3, these three portions of rotor being rigidly attached to the rotating body 59.

[0073] The first portion of rotor RI surrounds the first portion of stator SI, delimiting with it a first air gap El having a shape of revolution, to form a first module Ml of electric machine.

[0074] Similarly, the second rotor section R2 surrounds the second stator section S2, defining with it a second air gap E2 of revolution, to constitute a second electrical machine module M2. Likewise, the third rotor section R3 surrounds the third stator section S3, defining with it a third air gap E3 of revolution, to constitute a third electrical machine module M3.

[0075] This rotor 41 includes first magnets Al at the level of the first portion of rotor RI, second magnets A2 at the level of the second portion of rotor R2, and third magnets A3 at the level of the third portion of rotor R3, these magnets being thus radially opposite the corresponding windings of the stator 49.

[0076] As can be seen in [Fig. 4], the stator 49 has a larger external diameter at the second stator segment S2 than at the first stator segment SI, and an even larger external diameter at the third stator segment S3. Similarly, the internal diameter of the rotor 41 is larger at the second rotor segment R2 than at the first rotor segment RI, and it is even larger at the third rotor segment R3.

[0077] The diameter d2 of the air gap E2 is thus greater than the diameter dl of the air gap El, so that in general, the diameter of the module M2 is greater than that of the module ML. Similarly, the diameter d3 of the air gap E3 is greater than the diameter d2 of the air gap E2. The air gaps El, E2 and E3 thus have diameters that increase from upstream to downstream along the axis AX, which facilitates the assembly and disassembly of the electrical machine.

[0078] This makes it possible to occupy the internal space delimited by the compressor 2 in order to maximize the power of the electric machine while allowing assembly and disassembly in this internal space.

[0079] Windings B1, B2, and B3 are wired together, i.e., these windings are connected to each other in the stator 49. These modules M1, M2, and M3 thus together form a single electrical machine 52, having for example the same set of electrical terminals carried by its stator.

[0080] Furthermore, in the example of [Fig. 4], the electrical machine comprises three modules, but it could comprise two, four, or any other number. Electrical connections

[0081] Generally, the winding(s) of the electric machine are connected via power cables through the wall 57 of the inlet housing 12 to power cables extending inside the radial arms 13 in the case of the first embodiment.

[0082] The cable connection is advantageously achieved with pin connectors. For example, the male connector is carried by the downstream edge of the cone 23, and the female connector is carried by the wall 57, at a connection region R corresponding to the bearing area of ​​the edge 56 on the wall 57, and these two connectors extend parallel to the longitudinal direction AX. Under these conditions, when the fixed cone 23 is removed from the inlet housing 12, it is electrically disconnected. Similarly, when it is mounted, simply inserting it onto the wall 57 is sufficient to connect it electrically.

[0083] In the case of the second embodiment, they are connected to power cables in the same way, i.e. by means of pin connectors, through a wall of the intermediate housing. Cooling

[0084] Furthermore, the stator 49 advantageously includes internal hydraulic channels allowing oil, or another fluid, to circulate through it to cool the electric machine: the continuous assembly of the stator portions within the stator 49 allows for a common cooling circuit for the different stator portions.

[0085] Similarly, these hydraulic channels are then connected to hydraulic supply channels or conduits carried by the inlet housing 12 (or by the intermediate housing 18), by means of quick connectors. Benefits

[0086] By implementing an electrical machine comprising several modules having different diameters, the invention makes it possible to optimize the space available for the integration of an electrical machine.

[0087] The integration of the electric machine at the level of the inlet cone or the intermediate bearing allows it to be linked in rotation to the low pressure compressor, which corresponds to a cold zone which is therefore favorable to its cooling.

[0088] More generally, the invention can thus be applied to the integration of an electrical machine at the level of the inlet cone, the downstream cone or even a bearing support of the turbojet engine.

[0089] Choosing a single stator that brings together the different stator portions allows for optimizing the cooling of the stator elements through a common cooling circuit that can have a higher flow rate.

Claims

Demands

1. Turbojet (1) extending along a longitudinal axis (AX), comprising: - an inlet casing (12) extending upstream of a low-pressure compressor (2) of the turbojet (1); - a fixed cone (23) carried by the inlet casing (12) and extending upstream of this inlet casing (12); - an electrical machine (52) comprising several modules (M1, M2, M3) adjacent along the longitudinal axis (AX), each module (M1, M2, M3) comprising a portion of an electric rotor (RI, R2, R3) and a portion of an electric stator (SI, S2, S3) concentrically jointly defining an air gap (E1, E2, E3) of revolution; - the air gaps (E1, E2, E3) of two adjacent modules (M1, M2, M2) have different diameters; - the portions of electric rotors (RI, R2, R3) forming part of a rotor (41) linked in rotation to a low pressure body (9) of the turbojet (1);- each portion of the electric stator (SI, S2, S3) being provided with windings (B1, B2, B3), and the windings (B1, B2, B3) of the different portions of the stator (SI, S2, S3) being electrically connected to each other in the stator (49); characterized in that: - the portions of the electric stator (SI, S2) are carried by the fixed cone (23); - the portions of the electric rotor (RI, R2) extend inside the fixed cone (23) being surrounded by the portions of the stator (SI, S2).;

2. Turbojet (1) according to claim 1, in which the rotor (41) has a downstream end (39) engaged in a tubular part (27) of the low-pressure body (9) by being rotationally linked to the low-pressure body (9) by a grooved link (43).

3. Turbojet (1) according to claim 2, comprising a tie rod (37) carried by a cover screwed into a thread (36) of the tubular part (27), in which the downstream end (39) of the rotor has a bottom (42) through which this tie rod (37) passes, and in which the downstream end (39) of the rotor is axially retained by a nut (46) screwed onto the tie rod (37).

4. Turbojet (1) according to claim 2, wherein the fixed cone (23) has studs (53) by which it is fixed to the inlet casing (12), each stud (53) passing through an upstream wall (57) of the inlet casing (12).

5. Turbojet (1) according to claim 1, comprising at least three modules (M1, M2, M3), delimiting three air gaps (E1, E2, E3) of revolution, these air gaps (E1, E2, E3) having different diameters which are increasing from upstream (AM) to downstream (AV) of the turbojet (1).

6. Turbojet (1) according to any one of claims 2 to 5, wherein the stator (49) and the housing (12, 18) to which this stator (49) is fixed are equipped with pin electrical connectors for connecting the windings of the stator (49) to the turbojet (1).

7. Turbojet (1) according to any one of claims 2 to 5, wherein the stator (49) has oil circulation channels, and wherein the stator (49) and the housing (12, 18) to which this stator is fixed are equipped with quick connectors for connecting the channels of the stator (49) to the turbojet (1).

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