Bearing support designed to support two electric machines and connect them electrically, allowing ventilation of their rotors and pressurization of an internal chamber

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) comprising an upstream electric stator (Sam) carried by the bearing support (18), and a downstream electric machine (Mav) comprising 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) respectively an upstream enclosure (Eam) surrounding the upstream electric stator (Sam) and a downstream enclosure (Eav) surrounding the downstream electric stator (Sav); – channels formed in the body (28) for the circulation of cooling oil in the upstream and downstream enclosures (Eam, Eav);– at least one conduit (54) for receiving a power cable (51a), this conduit (54) opening into the downstream enclosure (Eav) and being equipped with a sealing element (58) to ensure, together with the power cable (51a-51c), the sealing of the downstream enclosure (Eav). Figure for the abbreviation: Figure 5;

Description

Title of the invention: Bearing support arranged to carry two electrical machines and connect them electrically while allowing ventilation of their rotors and pressurization of an internal enclosure 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 high pressure body 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] - channels formed in the body for the circulation of cooling oil in the upstream and downstream enclosures;

[0014] - at least one conduit for receiving a power cable, this conduit opening out in the downstream enclosure and being equipped with a sealing member to jointly ensure sealing of the downstream enclosure with the power cable, each power cable having its end connected to the downstream stator.

[0015] With this arrangement, the cables are cooled by air ventilation over their nominal length, and their ends, i.e. their connection portions likely to undergo greater heating, are efficiently cooled by oil circulation.

[0016] The invention also relates to a subassembly thus defined, in which the body comprises, opposite each conduit, an opening formed in its upstream face and opening into the downstream enclosure, and an upstream ferrule attached to the upstream face to close each opening.

[0017] Thanks to these openings, the connection of each cable end to the downstream stator is accessible to an operator to facilitate their assembly and disconnection during a maintenance operation.

[0018] The invention also relates to a subassembly thus defined, in which each power cable is connected to the stator by a terminal accessible through the corresponding opening in the upstream face.

[0019] The invention also relates to a subassembly thus defined, in which each cable is surrounded by a sheath connected to the conduit and having an internal diameter significantly greater than the external diameter of the cable to allow the circulation of ventilation air between the cable and its sheath.

[0020] The invention also relates to a subassembly thus defined, comprising an internal channel formed in the body, this internal channel having an intake opening located in the internal duct to collect ventilation air therein, this internal channel opening into the upstream face of the body to evacuate the ventilation air towards the upstream rotor in order to cool it.

[0021] The invention also relates to a subassembly thus defined, comprising an internal channel formed in the body, this internal channel having an intake opening located in the internal duct for collecting ventilation air therein, this internal channel opening into an internal enclosure of the bearing support to pressurize it.

[0022] The invention also relates to a subassembly thus defined, comprising at least one internal conduit for receiving a power cable, this conduit opening into the upstream enclosure and being equipped with a sealing member to jointly ensure with the power cable a sealing of the upstream enclosure, each power cable having its end connected to the upstream stator.

[0023] The invention also relates to a subassembly thus defined, in which each cable connected to the upstream stator is surrounded by a sheath having an internal diameter significantly greater than the external diameter of the cable to allow the circulation of ventilation air between the cable and its sheath.

[0024] The invention also relates to a subassembly thus defined, in which the bearing support comprises a rolling bearing, for guiding the low pressure body of the turbomachine in rotation.

[0025] The invention also 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 which shows the connection of an electric cable of the downstream stator;

[0031] [Fig.6] is a partial front view showing an opening with the connection terminal to which this opening provides access;

[0032] [Fig.7] is a partial sectional view showing an intake opening of an internal ventilation air circulation channel;

[0033] [Fig.8] is a partial view along a different sectional plane from that of [Fig.7] showing a discharge end of the internal ventilation air circulation channel;

[0034] [Fig.9] is a top half view of the bearing support showing the connection of an electrical cable of the upstream stator. DETAILED DESCRIPTION OF THE INVENTION

[0035] In [Fig.l], a turbojet 1 extending along an axis of rotation AX has 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 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 an external structure 3 forming its fairing and externally delimiting the secondary flow F2.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] As visible in [Fig.2], the inter-compressor bearing support 18 has a shape of revolution around the longitudinal axis AX. It carries in its central part an upstream portion of the low pressure body 9 by means of a roller bearing 24, to guide it in rotation.

[0044] The inter-compressor 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 ensure that the oil does not escape from this enclosure.

[0045] 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.

[0046] 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.

[0047] The upstream cover 29 delimits with the body 28 an upstream enclosure Eam which contains an upstream electric stator Sam surrounding 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.

[0048] 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.

[0049] The internal skirt 35 delimits with a downstream face of the body 28 and with a downstream cover 39 a downstream enclosure Eav enclosing a downstream stator Sav of an electric machine which is surrounded by a downstream rotor Rav to form a downstream electric machine Mav. The downstream stator Sav can also, conversely, be arranged to surround the downstream rotor Rav.

[0050] This downstream rotor Rav is carried by a bell 41 itself carried by the high pressure body 11 and which extends into the external skirt 34.

[0051] This high pressure body has its upstream end supported by a ball bearing 38 carried by a fixed internal flange 42 which is rigidly secured to the part 36 of the inter-compressor casing 17, to guide this high pressure body 11 in rotation and transmit its thrust forces to the inter-compressor casing 17.

[0052] 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.

[0053] The oil intake is ensured by two tubes 43 and 44 connected to the upper part of the skirt 34, and an oil discharge is ensured at the level of a collector 48 located at the lower part of the skirt 34, the recovery of this oil being ensured by two tubes 46 and 47 allowing the oil to be conveyed to a recirculation circuit.

[0054] The tubes 43, 44, 46 and 47 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.

[0055] Thanks to these tubes, and to channels not shown which are formed in the body 28, a circulation of cooling oil is ensured in the enclosures Eam and Eav so as to maintain the stators Sam and Sav at acceptable operating temperatures.

[0056] The power supply to the upstream stator Sam is provided by six electrical power cables 49a-49f which each pass through the body 28 from downstream to upstream to reach the windings of the upstream stator Sam. The power supply to the downstream stator Sav is provided by three electrical power cables 51a-51c passing radially through the skirt 34 to reach the windings of this stator Sav. 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.

[0057] As can be seen more clearly in [Fig. 5], the cable 51a is surrounded by a sheath 52 having an internal diameter significantly larger than the external diameter of the cable, so as to delimit with this cable an internal tubular space Eg allowing the circulation of ventilation air along this cable 51a.

[0058] This sheath is connected to an internal conduit 54 of the body 28 allowing the cable 51a to be engaged in the body in such a way that its free end 56 is located inside the downstream enclosure Eav of the stator Sav which is immersed in the cooling oil, facing a connection member 57 of this stator Sav in a direction parallel to the axis AX.

[0059] Additionally, a sealing member 58 resembling a series of O-rings extends circularly between the cable 51a and the internal conduit 54, to ensure a seal between the enclosure Eav containing the cooling oil and the tubular space Eg surrounding the cable 51a and containing ventilation air.

[0060] The free end 56 of the cable 51a and the connecting member 57 are fixed to each other by a bolt 59 to form a lug 61 extending into the enclosure Eav, but which is accessible via the upstream face of the body 28 thanks to an opening 62a formed in this upstream face.

[0061] This opening 62a appearing more clearly in [Fig.6], which has a lunule shape, is closed by the upstream ferrule 31 when the latter is fixed to the body 28, so as to seal the enclosure Eav.

[0062] In practice, during assembly, the operator passes the cable 51a into the sheath 52 until position its free end 56 at the level of the connecting member 57, visually checking the position of the free end 56 thanks to the opening 62a.

[0063] Once this positioning is completed, the operator passes a screw 63, in the space accessible thanks to the opening 62a, through the free end 56 and the connecting member. He can then place a nut 64 at the free end of the screw 63 and screw it onto it to form the bolt 59, then tighten this nut 64 to ensure the electrical connection of the cable 51a with the connecting member 57. As will have been understood, the connection of the cables 51b and 51c is ensured in the same way as that of the cable 51a.

[0064] After having carried out the same operation for the cables 51b and 51c, the operator can proceed to the assembly of the upstream ferrule 31, by fixing it to an upstream face 65 of the body 28, to close the three openings 62a-62c, corresponding to the cables 51a-51c, as visible in [Fig.4].

[0065] In operation, the connection lug of the cable 5la to the downstream stator Sav, which is likely to undergo significant heating, is effectively cooled by the circulation of oil ensured for the upstream stators Sam and downstream Sav.

[0066] In the example of the figures, the cables are connected to the downstream stator Sav by lugs, but they could also be connected by different electrical connectors, which according to the invention are cooled by the oil bath cooling the stators, given that such connectors can be subject to greater heating than the cables themselves.

[0067] As shown in Figures 7 and 8, an internal channel 66 formed in the body 28 is arranged to have its intake opening 67 opening into the region of the internal conduit 54 located beyond the sealing member 58, so as to collect the ventilation air which circulates along the cable 51a in the space Eg.

[0068] The opposite end of this internal channel 66 opens into the upstream face 65 of the body 28, and it is connected to a complementary hole 68 passing through the ferrule 31, by an internal sleeve 69. This complementary hole 68 opens opposite the upstream rotor Ram, so as to ventilate it to cool it.

[0069] In other words, the ventilation air circulating around the cable 51a is collected by the channel 66 at the level of the conduit 54, to then be injected towards the upstream rotor Ram so as to cool it.

[0070] In the same way, another internal channel not shown is advantageously provided by being arranged to also collect the ventilation air in the conduit 54, and to inject it into the internal enclosure E, so as to ensure the pressurization of this internal enclosure.

[0071] The connection of the upstream stator to the power cables 49a-49f is implemented without connection lugs: the upstream stator Sam is directly connected to the cables 49a-49f which are then engaged in corresponding conduits formed in the body 28, these conduits being analogous to the conduits 54.

[0072] The upstream stator Sam is then brought closer to the body 28 while sliding the cables 49a-49f into their respective conduits, after which it is positioned before proceeding with its fixing.

[0073] As visible in [Fig.9], the cables 49a-49f are advantageously surrounded by sheaths 52 allowing the circulation of ventilation air along these cables. Internal channels formed in the body 28 allow, in the same way as in the example of FIGS. 6 and 7, to collect the ventilation air to send it to the upstream rotor Ram and / or to the internal enclosure.

[0074] Generally speaking, the invention makes it possible to ensure the integration of two electrical machines with the cooling of its electrical cables and its upstream rotor by air ventilation, as well as the pressurization of the internal enclosure of the bearing.

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); - channels formed in the body (28) for the circulation of cooling oil in the upstream and downstream enclosures (Eam, Eav); - at least one conduit (54) formed in the body (28) receiving a power cable (51a-51c), this conduit (54) opening into the downstream enclosure (Eav) and being equipped with a sealing member (58) to ensure jointly with the power cable (51a-51c) a sealing of the downstream enclosure (Eav), each power cable (51a-51c) having its end connected to the downstream stator (Sav).;

2. Subassembly according to claim 1, in which the body (28) comprises, opposite each conduit (54), an opening (62a-62c) formed in its upstream face (65) and opening into the downstream enclosure (Eav), and an upstream ferrule (31) attached to the upstream face (65) to close each opening (62a-62c).

3. Subassembly according to claim 2, in which each power cable (51a-51c) is connected to the stator by a lug (61) accessible through the corresponding opening (62a-62c) of the upstream face.

4. Subassembly according to claim 1, in which each cable (51a-51c) is surrounded by a sheath (52) connected to the conduit (54) and having an internal diameter greater than the external diameter of the cable to allow ventilation air circulation between the cable (51a-51c) and its sheath (52).

5. Subassembly according to claim 4 comprising an internal channel (66) formed in the body (28), this internal channel (66) having an intake opening located in the duct (54) to collect ventilation air therein, this internal channel (66) opening into the upstream face (65) of the body (28) to evacuate the ventilation air towards the upstream rotor (Ram) in order to cool it.

6. Subassembly according to claim 4 comprising an internal channel formed in the body (28), this internal channel having an intake opening located in the duct (54) for collecting ventilation air therein, this internal channel opening into an internal enclosure of the bearing support (18) for pressurizing it.

7. Subassembly according to claim 1 comprising at least one internal conduit for receiving a power cable (49a-49f), this conduit opening into the upstream enclosure (Eam) and being equipped with a sealing member to ensure, together with the power cable (49a-49f), a sealing of the upstream enclosure (Eam), each power cable (49a-49f) having its end connected to the upstream stator (Sam).

8. Subassembly according to claim 1, in which each cable (49a-49f) connected to the upstream stator (Sam) is surrounded by a sheath having an internal diameter greater than the external diameter of the cable to allow the circulation of ventilation air between the cable (49a-49f) and its sheath (52).

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

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).

Images