Bearing support designed to support two electrical machines and allow the stators of these electrical machines to be cooled by oil circulation

Abstract

The invention relates to a turbomachine subassembly comprising: – an inter-compressor housing carrying a bearing support (18) including a body (28); – an upstream electric machine (Mam) including an upstream stator (Sam) carried by the support (18); – a downstream electric machine (Mav) including a downstream electric stator (Sav) carried by the bearing support (18); – an upstream cover (29) and a downstream cover (50) delimiting with the body (28) an upstream enclosure (Eam) containing the upstream electric stator (Sam) and a downstream enclosure (Eav) containing the downstream electric stator (Sav); – delivery channels (49) formed in the body (28) to receive oil and to circulate it in the enclosures (Eam, Eav), and return channels formed in the body (28) to collect the oil that has circulated in the enclosures (Eam, Eav). Figure for the summary: Figure 6

Description

Title of the invention: Bearing support arranged to carry two electrical machines and allow the stators of these electrical machines to be cooled by oil circulation Technical field

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

[0002] Taking into account in particular the growth of electrically powered systems, the aeronautical field is studying the integration of electrical machines within a turbojet, in particular to design a hybrid engine solution, these machines providing a motor and / or generator function.

[0003] Such a solution aims to use fossil fuel energy and electrical energy in order to drive the propulsion part of the engine and to electrically power certain functions of the engine and / or the aircraft that this engine equips.

[0004] In practice, such integration encounters multiple problems, since the compactness of the arrangement of the components present within existing motors leaves little space for the addition of an electric machine.

[0005] Different integration solutions have been considered, but they require either significantly modifying the general structure of the engine, or reducing the dimensions of the electrical machine that can be integrated, which reduces the electrical power that can be carried.

[0006] In this context, the aim of the invention is to provide a solution making it possible to integrate two electrical machines into a motor while minimizing the modifications to be made to this motor. Statement of the invention

[0007] To this end, the invention relates to a turbomachine subassembly comprising:

[0008] - a bearing support comprising a body;

[0009] - an inter-compressor casing carrying this bearing support;

[0010] - an upstream electrical machine comprising an upstream electrical stator carried by the bearing support and an upstream electric rotor surrounded by the electric stator or surrounding the electric stator, this upstream electric rotor being carried by a low pressure body of the turbomachine;

[0011] - a downstream electrical machine comprising a downstream electrical stator carried by the bearing support and a downstream electric rotor surrounding the downstream electric stator or surrounded by the downstream electric stator, this downstream electric rotor being carried by a body high pressure of the turbomachine;

[0012] - an upstream cover and a downstream cover delimiting with the body respectively an upstream enclosure containing the upstream electric stator and a downstream enclosure containing the downstream electric stator;

[0013] - conveying channels formed in the body for receiving cooling oil and to circulate it in the enclosures of the electric stators, and return channels formed in the body to collect the cooling oil having circulated in the enclosures;

[0014] - tubes extending in radial arms of the inter-compressor casing for to convey the oil to the body and to recover the oil that has circulated in the stator enclosures.

[0015] The invention thus makes it possible to integrate two electrical machines linked in rotation respectively with the high pressure body and with the low pressure body, in a region of the turbomachine having a relatively low temperature, while ensuring the bearing function to support one and / or the other of these two bodies, and the cooling of the stators of these electrical machines by circulation of oil.

[0016] The invention thus makes it possible to combine within a single part, namely the bearing support, all the functions relating to the two electrical machines that it carries.

[0017] For this purpose, the invention relates to a subassembly thus defined, comprising an internal enclosure delimited at least in part by the bearing support, and in which the body comprises distribution channels for admitting lubricating oil and injecting it into the internal enclosure, as well as return channels for collecting the lubricating oil having circulated in the enclosure.

[0018] For this purpose, the invention relates to a subassembly thus defined, comprising an upstream ferrule attached to an upstream face of the body, this upstream ferrule carrying a seal, and in which this upstream ferrule comprises a return channel which is connected to a return channel of the body by an internal sleeve to recover lubricating oil having passed through the seal.

[0019] To this end, the invention relates to a subassembly thus defined, in which the internal enclosure is closed downstream by a bell carried by the high pressure body which comprises radial holes allowing the lubricating oil to be evacuated from this enclosure to collect it in the body.

[0020] To this end, the invention relates to a subassembly thus defined, in which the body comprises a cylindrical skirt extending downstream and surrounding the bell, and in which this skirt carries an oil collector located on its external face, and in which the cylindrical skirt comprises a through opening which opens into this collector.

[0021] For this purpose, the invention relates to a subassembly thus defined, in which at at least one return channel for the distribution oil opens into the manifold.

[0022] To this end, the invention relates to a subassembly thus defined, in which the stators are provided with internal channels for circulating cooling oil.

[0023] To this end, the invention relates to a subassembly thus defined, in which the downstream cover comprises a cylindrical sheet metal shell extended by a crown-shaped flange formed from sheet metal, to delimit the downstream enclosure jointly with a downstream face of the body and with an internal skirt of this body extending towards its downstream, the flange and the shell surrounding this internal skirt.

[0024] To this end, the invention relates to a subassembly thus defined, in which the bearing support comprises a rolling bearing, for guiding in rotation an upstream portion of the low pressure body of the turbomachine.

[0025] To this end, the invention relates to a subassembly thus defined, in which the inter-compressor casing comprises a ball bearing for carrying an upstream end of the high pressure body. Brief description of the drawings

[0026] [Fig.l] is a longitudinal sectional view of a dual-flow twin-spool turbojet engine;

[0027] [Fig.2] is a longitudinal sectional view of the bearing support according to the invention with its environment in a turbojet;

[0028] [Fig.3] is a perspective view of the bearing support body;

[0029] [Fig.4] is another perspective view of the bearing support;

[0030] [Fig.5] is a top half view of the bearing support in a sectional plane containing its axis of revolution and intersecting a lubrication channel of the internal enclosure;

[0031] [Fig.6] is a half top view of the bearing support in a section plane containing its axis of revolution and intersecting an oil conveying channel towards the downstream stator;

[0032] [Fig.7] is a top half view of the bearing support in a section plane containing its axis of revolution and intersecting an oil conveying channel towards the upstream stator;

[0033] [Fig.8] is a lower half sectional view of the bearing support in a sectional plane containing its axis of revolution and intersecting lower oil collection channels. DETAILED DESCRIPTION OF THE INVENTION

[0034] In [Fig.l], a turbojet 1 extending along an axis of rotation AX comprises at its upstream AM an inlet sleeve through which the air is admitted to pass through a low pressure compressor 2 before being split into a primary flow central Fl and a secondary flow F2 surrounding the primary flow.

[0035] These flows circulate in the turbojet 1 from upstream AM to downstream AV, this turbojet being delimited externally by an external structure 3 forming its fairing and externally delimiting the secondary flow F2.

[0036] The primary flow is then compressed in a high-pressure compressor 4 before arriving in 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 is directed directly to the rear.

[0037] As visible in [Fig. 1], the low pressure compressor 2 and the low pressure turbine 7 comprise moving blades carried by a rotating assembly constituting a low pressure body 9. Similarly, the high pressure compressor 4 and the high pressure turbine 6 comprise moving blades carried by the same high pressure body 11, which surrounds the low pressure body while being independent in rotation thereof, these two bodies rotating around a longitudinal axis AX.

[0038] Advantageously, this engine comprises upstream of the low pressure compressor 2 an inlet casing 12, comprising radial arms by which it is secured to the external structure 3. An upstream bearing 13 mounted in this inlet casing 12 carries in rotation an upstream part of the low pressure body 9.

[0039] This inlet casing 12 is extended upstream by a fixed cone 16, directing the incoming flow around the central part comprising the high and low pressure bodies, minimizing the induced aerodynamic losses.

[0040] This engine comprises between the low pressure compressor 2 and the high pressure compressor 4 an inter-compressor casing 17, comprising radial arms by which it is secured to elements of the external structure 3. An inter-compressor bearing support 18 mounted in this inter-compressor casing 17 carries in rotation an upstream part of the low pressure body 9 and an upstream part of the high pressure body 11.

[0041] As visible in [Fig.2], the low pressure compressor 2 comprises rotating blades 19 carried by the low pressure body 9, and fixed blades 21 rigidly secured to the external structure 3. Similarly, the high pressure compressor 4 comprises fixed blades 22 rigidly secured to the structure 3 and rotating blades 23 carried by the high pressure body 11.

[0042] As visible in [Fig. 2], the bearing support 18 has a shape of revolution around the longitudinal axis AX, and it carries in its central part an upstream portion of the low pressure body 9 by means of a roller bearing 24

[0043] The support 18 carries upstream of the bearing 24 a seal 27 which ensures a seal with the low pressure body 9, to delimit an internal enclosure E in which the bearing 24 is located. A circulation of pressurized air is ensured towards the internal space which contains an oil mist, so as to lubricate the bearings and to ensure that the oil does not come out of this enclosure.

[0044] The support 18 is a revolution element comprising a main body 28, an upstream cover 29 and an upstream ferrule 31, which are rigidly secured to the upstream face of this body 28.

[0045] This body 28 comprises a median external flange 32, that is to say located substantially at half its length along the axis AX, by which it is fixed to an upstream internal flange 33 of the casing 17, and it comprises an external cylindrical skirt 34 extending downstream and by the end of which it is secured to a downstream internal part 36 of the casing 17. This body also comprises an internal skirt 35, also cylindrical, which extends downstream inside the skirt 34.

[0046] The upstream cover 29 contains an upstream electric stator Sam which surrounds an upstream rotor Ram carried by the low pressure body 9, to form an upstream electric machine Mam. The upstream electric stator Sam can also, conversely, be arranged to be surrounded by the upstream electric rotor Ram.

[0047] The upstream ferrule 31 is a revolution element carried by the upstream face of the body 28, it extends radially inside the cover 29. This ferrule 31 carries the seal 27, a portion of the low pressure body sliding against an internal face of this seal 27 to ensure the upstream sealing of the internal enclosure E.

[0048] In its downstream portion, this body 28 carries a downstream stator Sav of an electric machine which is surrounded by a downstream rotor Rav carried by the high pressure body 11 to form a downstream electric machine Mav. The downstream stator Sav can also, conversely, be arranged to surround the downstream rotor Rav.

[0049] This high pressure body has its upstream end supported by a ball bearing 38 carried by a fixed internal flange 39 which is rigidly secured to the part 36 of the inter-compressor casing 17, to guide the high pressure body 11 in rotation and to transmit its thrust forces towards the inter-compressor casing 17.

[0050] The body 28 which appears alone in figures 3 and 4 has a general shape of revolution around the axis AX. It is arranged to support the stators Sam and Sav, to allow their electrical connection, their cooling by oil circulation, and the admission of air into the internal enclosure E.

[0051] The oil intake is ensured by two tubes 41 and 42 connected to the upper part of the skirt 34, and an oil discharge is ensured at the level of a collector 43 located at the lower part of the skirt 34, the recovery of this oil being ensured by two tubes 44 and 45 making it possible to convey the oil to a recirculation circuit.

[0052] In practice, the tubes 41, 42, 44 and 45 extend in radial arms (not shown) of the inter-compressor casing 17, so as to ensure supply and recovery of the oil from a hydraulic circuit located outside the bearing support 18 and the inter-compressor casing 17.

[0053] The power supply to the upstream stator Sam is provided by six electrical power cables 46a-46f which each pass through the body 28 from downstream to upstream to reach the windings of the upstream stator Sam to which they are connected. The power supply to the downstream stator Sav is provided by three electrical power cables 47a-47c passing radially through the skirt 34 to reach the windings of this stator Sav to which they are connected. These electrical cables are routed from a region external to the casing 17 to the support 18 by extending inside radial arms of the casing 17 not shown in the figures.

[0054] As visible in Figure 5, the body 28 is provided to ensure the distribution of oil conveyed by the tube 41 to the internal enclosure via a distribution channel 48, where it is distributed by one or more nozzles not shown, to lubricate this enclosure E, and the oil supplied by the tube 42 to the stators Sam and Sav to cool them.

[0055] The distribution channel 48 comprises a longitudinal portion 48a formed on the external face of the skirt 34, extended by a radial portion 48b passing through the body 28 itself to open onto its cylindrical internal face, located downstream of the radial seal 27 and delimiting the enclosure E.

[0056] As visible in [Fig.6], the cooling oil coming from the tube 42 is first directed towards the downstream stator Sav by a routing channel 49 passing through the body 28, to reach a downstream enclosure Eav containing the stator Sav. The channel 49 advantageously opens into a circumferential channel (not shown) which is connected to the downstream enclosure Eav by a series of channels parallel to the axis AX regularly distributed around this axis, to distribute the cooling oil over the entire circumference of the downstream enclosure Eav.

[0057] This downstream enclosure Eav is delimited by the cylindrical internal skirt 35 of the body 28, and by a downstream cover 50 comprising a cylindrical sheet metal ferrule 51 extending between the skirts 34 and 35 terminated by a crown-shaped flange 52 by which it is connected to the skirt 35. This downstream cover 50 delimits, jointly with the body 28 and its skirt 35, the downstream enclosure Eav which contains the downstream stator Sav.

[0058] The conveying channel 49 comprises a radial portion 49a extended by a longitudinal portion 49b opening into the downstream enclosure at an external face of the internal skirt 35. The cooling oil thus circulates in the enclosure Eav around the stator Sav by circulating downstream along its radially internal face, then circulating upstream through the thickness of this stator Sav, for example in internal channels of the stator dedicated to its cooling.

[0059] After passing through the stator Sav from downstream to upstream, the cooling oil passes through the body 28 towards the upstream through a through-conveying channel 53 to reach an upstream enclosure Eam containing the upstream stator Sam, as seen in [Fig.7]. This upstream enclosure Eam is delimited by the upstream cover 29 having a toric shape with a U-shaped section, and by the upstream face of the body 28 to which this cover is fixed. Advantageously, the body 28 comprises a series of through channels regularly distributed around the axis AX, so as to ensure a uniform transfer of the oil from the downstream enclosure Eav to the upstream enclosure Eam.

[0060] This oil then circulates upstream through internal cooling channels of the stator Sam, to then run along the radially external face of this stator Sam before being evacuated via the collector 43, as illustrated in [Fig.8].

[0061] For this purpose, the upstream cover 29 comprises in its lower region a collection channel 54 appearing in [Fig. 8], which is connected by an internal sleeve 56 to a return channel 57 formed in the body 28 and running along a lower face of the collector 43.

[0062] Thus, the cooling oil injected by the tube 41 first circulates through the downstream stator Sav through the upstream stator Sam to cool them, and it is then collected by the channels 54 then 57 visible in [Fig.8] in order to be evacuated into the tube 45 (connected to the channel 57) to be conveyed to a recirculation circuit.

[0063] Several channels 54 and 57 are advantageously provided by being distributed circumferentially and extending parallel to each other. The channels 54 advantageously have helical orientations to facilitate the collection of oil which can circulate circumferentially in the enclosure Eav.

[0064] The lubricating oil of the internal enclosure E, which is conveyed by the tube 42, is projected onto the bearings, a part of which is therefore dispersed in the enclosure E where it mixes with the air to form an aerosol-type mixture with it, descends by gravity towards the lower portion of the enclosure E to be recovered by a return channel 58 passing radially through the body 28 and opening inside the collector 43, so as to be evacuated by the tube 44 towards a recirculation circuit.

[0065] Additionally, the upstream shell 31 which carries the seal 27 is provided with a return channel 59 connected to the channel 58 by another internal sleeve 61, which thus makes it possible to recover and evacuate the oil leaks having passed from downstream to upstream of the seal 27, so that it too is recirculated.

[0066] The lubricating oil of enclosure E also circulates in the region of enclosure E which is located downstream of the downstream electrical machine Mav, as represented schematically by the arrows located in the right part of [Fig.8].

[0067] More particularly, the downstream rotor Rav is carried by a rotating bell 62 rigidly secured to the high-pressure body 11 and extending upstream in the body 28, radially between the external skirt 34 and the downstream stator Sav. The lubricating oil droplets from the enclosure E circulating in the region located longitudinally between the flange 52 and the bell 62 are centrifuged by the bell 62 and re collected by radial holes 63 of this bell 62 to pass through it radially and then flow to the internal face of the external skirt 34.

[0068] As visible in [Fig.8], the lower portion of this skirt 34 comprises an oblong opening 64 situated radially opposite the collector 43, so that the oil droplets flowing on the internal face of this skirt 34 pass through this opening to be recovered in the collector 43 in order to be evacuated into the tube 44.

[0069] In a similar manner, the oil droplets that may be in the space located downstream of the bell 62 are centrifuged by the latter to be collected on the internal face of the skirt 34 in order to also be recovered in the collector 43, via the opening 64.

Claims

Claims

1. A turbomachine subassembly comprising: - a bearing support (18) comprising a body (28); - an inter-compressor casing (17) carrying this bearing support (18); - an upstream electrical machine (Mam) comprising an upstream electrical stator (Sam) carried by the bearing support (18) and an upstream electrical rotor (Ram) surrounded by the electrical stator (Sam) or surrounding the electrical stator (Sam), this upstream electrical rotor (Ram) being carried by a low-pressure body (9) of the turbomachine; - a downstream electrical machine (Mav) comprising a downstream electrical stator (Sav) carried by the bearing support (18) and a downstream electrical rotor (Rav) surrounding the downstream electrical stator (Sav) or surrounded by the downstream electrical stator (Sav), this downstream electrical rotor (Rav) being carried by a high-pressure body (11) of the turbomachine;- an upstream cover (29) and a downstream cover (50) delimiting with the body (28) respectively an upstream enclosure (Eam) containing the upstream electric stator (Sam) and a downstream enclosure (Eav) containing the downstream electric stator (Sav); - conveying channels (49, 53) formed in the body (28) to receive cooling oil and to circulate it in the enclosures (Eam, Eav) of the electric stators (Sam, Sav), and return channels (57) formed in the body (28) to collect the cooling oil having circulated in the enclosures (Eam, Eav); - tubes (41, 42, 44, 45) extending in radial arms of the inter-compressor casing to convey the oil to the body (28) and to recover the oil having circulated in the enclosures (Eam, Eav) of the stators (Sam, Sav).;

2. Subassembly according to claim 1, comprising an internal enclosure (E) delimited at least in part by the bearing support (18), and in which the body (28) comprises distribution channels (48) for admitting lubricating oil and injecting it into the internal enclosure (E), as well as return channels (58, 59) for collecting the lubricating oil having circulated in the enclosure.

3. Subassembly according to claim 2, comprising an upstream ferrule (31) attached to an upstream face of the body (28), this upstream ferrule (31) carrying a seal (27), and in which this upstream ferrule (31) comprises a return channel (59) which is connected to a return channel (58) of the body by an internal sleeve (61) to recover lubricating oil having passed through the seal (27).

4. Subassembly according to claim 2, in which the internal enclosure (E) is closed downstream by a bell (62) carried by the high pressure body (11) which comprises radial holes (63) allowing the lubricating oil to be evacuated from this enclosure to collect it in the body (28).

5. Subassembly according to claim 4, in which the body comprises a cylindrical skirt (34) extending downstream and surrounding the bell (62), and in which this skirt (34) carries an oil collector (43) located on its external face, and in which the cylindrical skirt (34) comprises a through opening (64) which opens into this collector (43).

6. Subassembly according to claims 3 and 5, in which at least one return channel (58, 59) for the distribution oil opens into the collector (43).

7. Subassembly according to one of the preceding claims, in which the stators (Sam, Sav) are provided with internal channels for circulating cooling oil.

8. Subassembly according to one of the preceding claims, in which the downstream cover (50) comprises a cylindrical ferrule (51) made of sheet metal extended by a flange (52) in the form of a crown formed of sheet metal, to delimit the downstream enclosure (Eav) jointly with a downstream face of the body (28) and with an internal skirt (35) of this body extending towards its downstream, the flange (52) and the ferrule (51) surrounding this internal skirt (35).

9. Subassembly according to one of the preceding claims, in which the bearing support (18) comprises a rolling bearing (24), for guiding in rotation an upstream portion of the low pressure body (9) of the turbomachine.

10. Subassembly according to one of the preceding claims, in which the inter-compressor casing (17) comprises a ball bearing (38) for carrying an upstream end of the high pressure body (11).

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