Turbomachine equipped with a disconnectable electric machine and with a bearing member for disconnection thereof

Abstract

The invention relates to a turbomachine (1) for an aircraft, comprising: - a low-pressure shaft (2) extending along a longitudinal axis (X) as far as a rear end (3), - a turbomachine stator (4) supporting the rear end (3) of the low-pressure shaft (2) by means of a rear bearing (6), - an electric machine (10) located at the rear of the turbomachine and comprising an electric machine stator (15) fixed to the stator (4) of the turbomachine and an electric machine rotor (16) supported by the stator (4) of the turbomachine via at least one bearing (35), - a connecting shaft (24) extending the low-pressure shaft (2) towards the rear along the longitudinal axis and capable of rotating the electric machine rotor (16) in a disconnectable manner by means of the low-pressure shaft, and - an actuator (40) configured to move the connecting shaft (24) into a decoupling position and comprising a fixed body (41) connected to the stator of the turbomachine, the actuator (40) comprises at least one bearing member (55) connected to a mobile body (42) that is movable relative to the fixed body (41) of the actuator (40), and intended to come into contact with an abutment surface (56) which is oriented in a direction different from the longitudinal axis (X) and borne by the connecting shaft (24) which is capable of rotating said bearing member (55) relative to the mobile body (42), the bearing member (55) comprising at least one part mounted with the freedom to rotate on an arm (57) which is mounted on the mobile body (42), the arm (57) being capable of moving relative to the mobile body (42) between a retracted position and an active position.

Description

Description TITLE: TURBOMACHINE EQUIPPED WITH A DISCONNECTABLE ELECTRIC MACHINE AND A SUPPORT DEVICE FOR ITS DISCONNECT Technical field of the invention

[0001] The present invention relates to the field of turbomachines, and in particular aircraft. It relates in particular to a turbomachine equipped with an electric machine which is arranged at the rear of the turbomachine. Technological background

[0001] The prior art includes documents FR3-A1-124541, FR-A1-3129970 and FR-A1-3123375.

[0002] Faced with the environmental challenge in the aeronautical field and the increasing need for electrical power concomitantly with the number of equipment and new functions of the aircraft, the question of the hybridization of the turbomachinery arises. The electric machine which equips the accessory boxes known by the English acronym AGB (for Accessory Gear Box) does not allow a significant gain in electrical power for all the functions of the aircraft and the efficiency of the conversion of mechanical power into electrical power is not at its optimum.

[0003] An electric machine is an electromechanical device based on electromagnetism that allows the conversion of electrical energy, for example, into mechanical energy (generator mode) or reversibly, allowing the production of electricity from mechanical energy (motor mode). The electric machine can behave equally in generator mode as in motor mode.

[0004] It is known to integrate the electric machine at the rear of the turbomachine where there is space for its integration and where high temperature constraints and other layout difficulties apply.

[0005] An example of an electric machine placed at the rear of the turbomachine comprises a rotor which is rotationally coupled with the low-pressure shaft of the turbomachine which extends furthest to the rear of the turbomachine. However, the rotor of the electric machine is not mounted directly on a rear end of the low-pressure shaft but on a connecting shaft so as not to weigh down the low-pressure shaft and also because of the increasingly reduced size of the shafts of the turbomachine. The electric machine is mounted independently of the rest of the turbomachine so as to facilitate its maintenance using a connection device which is configured so as to couple or uncouple the connecting shaft which is rotationally fixed to the rotor of the electric machine from the low-pressure shaft, for example in the event of damage.The connection device comprises a rod or finger actuated by an actuator mounted on a stator of the turbomachine and acting directly on the connecting shaft to move it and cause it to disconnect from the low pressure shaft. An example of an electrical machine at the rear of the turbomachine cooperating with a connection device equipped with a finger is described in document FR-A1-3130323.

[0006] However, such direct contact induces significant friction between parts that are in different reference frames and operate at different speeds, which can lead to a safety risk (e.g. a fire) and impact the service life of the actuator and the connecting shaft.

[0007] There is a need to address some or all of the above drawbacks. Summary of the invention

[0008] The objective of the present invention is to provide a solution for making a transition between disconnection / connection means of a connecting shaft rotating an electric machine which is independent and autonomous in terms of arrangement, and said connecting shaft in a simple, economical, durable, repetitive and robust manner.

[0009] We achieve this objective in accordance with the invention by means of a turbomachine, in particular for aircraft, comprising: - a low pressure shaft extending along a longitudinal axis to a rear end, - a turbomachine stator supporting the rear end of the low pressure shaft by a rear bearing, - an electric machine, located at the rear of the turbomachine, comprising an electric machine stator fixed to the stator of the turbomachine and an electric machine rotor supported by the stator of the turbomachine via at least one bearing, - a connecting shaft extending the low pressure shaft rearwardly along the longitudinal axis and capable of driving the rotor of the electric machine in rotation in a disconnectable manner via the low pressure shaft, and - an actuator configured to move the connecting shaft into a decoupling position and comprising a fixed body connected to the stator of the turbomachine, the actuator comprising at least one support member connected to a body movable relative to the fixed body of the actuator and intended to come into contact with a stop surface of the connecting shaft which is capable of driving said member in rotation.

[0010] Thus, this solution makes it possible to achieve the aforementioned objective. In particular, this configuration makes it possible to limit the number of rotating parts at the level of the means for disconnecting a rotor (connecting shaft) by a stator (here a part of the actuator). There is only the at least one support member in transition with the stator and the rotor. The contacting of the support member which is pivoting on the connecting shaft makes it possible to avoid direct contact of a stator part on the connecting shaft which makes it possible to cancel the movement of the rotor of the electric machine.Furthermore, this solution is also non-destructive and reversible because it allows the integrity of the connecting shaft to be preserved to disconnect the electric machine for the purpose of subsequent maintenance of the latter and to be able to reconnect the electric machine once it is in working order so that it is re-driven by the low pressure shaft via the connecting shaft. In addition, the contacting member is simple and does not require major modification of the actuator. Maintaining the actuator at the stator reference point helps to contain the costs of the turbomachine.

[0011] The turbomachine also includes one or more of the following features and / or steps, taken alone or in combination: - the connecting shaft comprises at a first end first dog teeth which are intended to mesh or disengage with second dog teeth located at the rear end of the low pressure shaft. - the support member is mounted freely rotatable on an arm which is carried by a collar fixed to one end of the movable body, the collar being centered on the longitudinal axis. - the turbomachine comprises a locking member configured so as to lock the connecting shaft in its coupling position. - the locking member is mounted to move radially relative to a rotor shaft of the electrical machine and comprises a head intended to slide and to be housed in an orifice of the connecting shaft. - a second elastic element is configured to move the connecting shaft into a coupling position with the low pressure shaft, the second elastic element extending along the longitudinal axis between a first stop surface of the electric machine rotor and a second stop surface of the connecting shaft. - the arm is able to move between a retracted position in which the support member is close to the collar and an active position in which the support member is at a distance from the collar. - a third elastic element is configured to move the arm from the retracted position to an active position. - the rear bearing is arranged in a first lubrication enclosure and in that the turbomachine comprises a lubrication circuit comprising a pipe which is formed in a thickness of a portion of the rear end of the low pressure shaft and which opens into the first enclosure. - the electrical machine and the support member are contained in a second enclosure which is separate from the first lubrication enclosure, the first enclosure and the second enclosure being separated at least in part by a seal. - the rotor shaft of the electric machine is supported by at least one rotation bearing which is arranged in the first enclosure. - - sealing gaskets are arranged on either side of the connection device. - - the stop surface is carried by the connecting shaft.

[0012] The invention relates to an aircraft comprising at least one turbomachine having any one of the aforementioned characteristics. Brief description of the figures

[0013] The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly on reading the detailed explanatory description which follows, of embodiments of the invention given as purely illustrative and non-limiting examples, with reference to the appended schematic drawings in which: - Figure 1 is a schematic and partial axial sectional view of an example of a turbomachine to which the invention applies; - Figure 2 is a perspective view of an exemplary embodiment of a control means intended to act on a connecting shaft of the turbomachine according to the invention; - Figure 3 illustrates in an axial and partial sectional view an example of a control means equipped with a member configured to move a connecting shaft according to the invention; - Figure 4 represents the member cooperating with the connecting shaft according to figure 3; - Figure 5 shows the connecting shaft disconnected from the low pressure shaft according to Figure 4; - Figure 6 is an axial sectional view of an example of a control means with a transition or support member configured to move a connecting shaft into a position before the installation of the control means according to the invention; - Figure 7 is an axial sectional view of the transition member in a retracted position and the control means coupled to other members of the turbomachine according to Figure 6; and - Figure 8 is an axial sectional view of the transition member in an active position according to Figure 6. Detailed description of the invention

[0014] Figure 1 schematically and partially represents a turbomachine 1 with longitudinal axis X to which the invention applies. The turbomachine 1 is intended to be mounted on an aircraft. In particular, the turbomachine may be a turbojet, a turboprop, a turboshaft or generally a turbomachine which comprises a fan or a propeller which is ducted or not ducted. Only the rearmost or downstream part of the turbomachine along the longitudinal axis X is shown in Figure 1.

[0015] In the present invention, and generally, the terms "upstream" and "downstream" are defined with respect to the circulation of gases or air flows in the turbomachine and here along the longitudinal axis X. The terms "axial" and "axially" are defined with respect to the longitudinal axis X. The terms "external", "external", "internal", "internal" and "radial" are defined with respect to a radial axis Z which extends from the longitudinal axis X and with respect to the distance from the longitudinal axis X. The radial axis Z is perpendicular to the longitudinal axis X.

[0016] The turbomachine 1 comprises a low-pressure shaft 2 which extends along the longitudinal axis X and up to a rear end 3. Advantageously, the low-pressure shaft 2 is coupled to a rotor of a turbine (not shown) of the turbomachine. In particular, the turbine considered, but not limited to, is the low-pressure turbine. The rotor of the low-pressure turbine is generally connected via the low-pressure shaft 2 to a rotor of a low-pressure compressor (not shown) which is located further upstream in the turbomachine along the longitudinal axis X.

[0017] The low pressure shaft 2 is supported by a stator 4 of the turbomachine using several bearings. The stator 4 is for example a casing and preferably an exhaust casing 5. More precisely, the turbomachine comprises a rear bearing 6 allowing the stator 4 to support the rear end 3 of the low pressure shaft 2. Optionally, the rear bearing 6 comprises an inner ring 6a secured to the rear end 6 of the low pressure shaft 2 and an outer ring 6b secured to a cylindrical bearing surface 7a of the stator 4 of the turbomachine. The cylindrical bearing surface 7a is for example secured to a bearing support 7. Rolling members 6c, for example rollers, are arranged between the inner and outer rings 6a, 6b.

[0018] Advantageously, the rear bearing 6 is arranged in a first lubrication enclosure 8. This first lubrication enclosure 8 is for example closed by means of one or more seals 9 which are arranged between walls (of the shaft, of the ferrule, etc.) delimiting the first enclosure 8.

[0019] The turbomachine 1 comprises an electric machine 10 which is located at the rear of the turbomachine 1. The electric machine 10 is advantageously housed in a cavity 11 which is formed downstream of the rear end 3 of the low pressure shaft. In other words, the electrical machine 10 is arranged downstream of the rear end 3 of the low pressure shaft 2. The cavity 11 is closed at least in part by a cover 12 which is fixed to the stator 4, and here to the exhaust casing 5 of the turbomachine, by a bolted connection (not shown) for example. A thermal protection 14 can be applied to the internal wall of the cover 12 to protect the latter from the heat produced by the exhaust gases at the outlet of the low pressure turbine (not shown) of the turbomachine.

[0020] The electric machine 10 comprises a stator 15 and a rotor 16. The electric machine 10 can alternately operate in generator mode and in motor mode. That is, the electric machine 10 can take power from the low-pressure shaft or inject power onto the low-pressure shaft 2. Advantageously, but not limitingly, the electric machine stator 15 comprises powered stator windings (or coils) and the electric machine rotor 16 comprises permanent magnets. The stator windings are intended to be electrically powered.

[0021] In the present example, the stator 15 of the electric machine 10 surrounds the rotor 16 of the electric machine 10 and is fixed to the stator 4 of the turbomachine. As shown in FIG. 1, the cover 12 equipped with the thermal protection 14 advantageously surrounds the stator 15 of the electric machine 10.

[0022] Advantageously, but not limitingly, the stator 15 comprises a body 17 which extends, along the longitudinal axis X, between a first end 18 and a second end 19. A first annular ferrule 20, centered on the longitudinal axis X, extends from the first end 18 and is fixed to the exhaust casing 5. The first annular ferrule 20 is provided for example with a flange 21 which is fixed to a flange 22 of the exhaust casing 5 by means of a bolted connection 23 for example. Advantageously, but not limitingly, the bolted connection 23 is of the axial type. Other means for securing or detaching the stator 15 of the electrical machine from the stator 4 of the turbomachine are conceivable.

[0023] The rotor 16 of the electric machine 10 is advantageously driven by the low pressure shaft 2 in a disconnectable manner. This is made possible by a connecting shaft 24 which makes it possible to transmit the rotational movement of the low pressure shaft 2 to the electric machine rotor 16. The connecting shaft 24 is configured so as to couple or uncouple in rotation from the rotor 16 of the electric machine 10. The uncoupling can occur in the event of damage to the electric machine 10 which would require the rotor 16 of the electric machine 10 to no longer be driven by the low pressure shaft 2. The rotor 16 of the electric machine can be blocked and impact the operation of the turbomachine and its drag. Disconnecting the rotor 16 from the electric machine makes it possible to avoid stopping the low pressure shaft 2 which would cause the turbomachine to shut down.In the case where the turbomachine is switched off but not blocked, the fan or propeller rotates naturally which limits its drag.

[0024] For this purpose and as shown in FIG. 1, the connecting shaft 24 extends along the longitudinal axis X, and in particular between a first end 25 and a second end 26. The connecting shaft 24 extends downstream of the rear end 3 of the low pressure shaft 2 and extends the low pressure shaft 2 towards the rear of the turbomachine 1. The connecting shaft 24 is advantageously coaxial with the low pressure shaft 2.

[0025] Coupling means 27 are provided for coupling or uncoupling the electric machine rotor 16 from the low-pressure shaft 2. The coupling means 27 comprise first dog teeth 28 which are carried by the connecting shaft 24 and which are intended to mesh with second dog teeth 29 carried by the low-pressure shaft 2. Advantageously, but not limitingly, the first dog teeth 28 are arranged at the first end 25 of the connecting shaft 24. The dog teeth 28, 29 are in the form of an annular row and each preferably extend axially. Similarly, the second dog teeth 29 are positioned at the rear end 3 of the low-pressure shaft 2. The second dog teeth 29 are complementary to first teeth 28 and advantageously have the same configuration.

[0026] The electric machine 10 comprises a rotor shaft 30 which is on the one hand integral in rotation with the rotor 16 of the electric machine 10 and which is on the other hand connected to the connecting shaft 24. The connection of the rotor shaft 30 and the electric machine rotor 16 is achieved for example using tight splines 31. A nut 32, centered on the longitudinal axis X, makes it possible to axially lock, downstream, the electric machine rotor 16 on the rotor shaft 30. The electric machine rotor 16 is axially locked, upstream, on the rotor shaft 30, by a radial shoulder 33 provided on the rotor shaft 30. In other words, the electric machine rotor 16 is axially immobile relative to the rotor shaft 30.

[0027] The rotor shaft 30 is advantageously, but not limited to, hollow and is mounted around the connecting shaft 24 in a coaxial manner. The connecting shaft 24 is also hollow. More precisely, the rotor shaft 30 is mounted so as to rotate with the connecting shaft 24. The rotor shaft 30 and the connecting shaft 24 are secured together using, for example, sliding splines 34. These sliding splines 34 allow the connecting shaft 24 to move axially relative to the rotor shaft 30. In particular, the connecting shaft 24 and the rotor shaft 30 each comprise splines which cooperate with each other and extend along the longitudinal axis X. The connecting shaft 24 is in fact configured so as to move between a coupling position in which it is coupled with the low-pressure shaft 2 and a decoupling position in which the connecting shaft 24 is not coupled to the low-pressure shaft 2.

[0028] With reference to Figure 1, the rotor shaft 30 is supported by at least one rotation bearing 35. In the present embodiment, there are two rotation bearings called first bearing 351 and second bearing 352. Each rotation bearing 351, 352 comprises an inner ring 35a secured to the rotor shaft 30 and an outer ring 35b secured to a bearing support 36. The bearing support 36 is advantageously, but not limited to, fixed to the bearing support 7. The fixing is carried out for example by means of removable fixing members 37 such as bolts. This makes it possible to block the axial movement of the rotor shaft 30. Rolling members 35c are arranged between the inner ring 35a and the outer ring 35b. In this embodiment, the inner ring 35a and the outer ring 35b of the first bearing 351 are each axially locked, upstream, by a nut 38, and downstream by shoulders 39. The inner ring 35a and the outer ring 35b of the second bearing 352 are each axially blocked, upstream, by shoulders.

[0029] Advantageously, but not limited to, the rolling members 35c are balls for the first bearing 351 and rollers for the second bearing 352.

[0030] Alternatively, the rolling members 35c for both bearings are balls. In this case, a radial preload between the balls is necessary. According to yet another alternative, the rolling members 35c of one of the bearings comprises balls and the other of the bearings comprises tapered rollers. In other words, the electric machine 10 is on its own rotating bearings.

[0031] According to the example shown, the first bearing 351 is arranged upstream of the rear bearing 6 and the second bearing 352 is arranged downstream of the rear bearing 6.

[0032] In this way, the low pressure shaft 2 drives the rotor 16 of the electrical machine 10 in rotation via the connecting shaft 24, the rotor shaft 30 and the dog teeth 28, 29 which are engaged with each other in the coupling position of the connecting shaft 24.

[0033] If it is necessary to uncouple the rotor 16 of the electric machine 10 and the low pressure shaft 2, the first dog teeth 28 disengage from the second dog teeth 29. The connecting shaft 24 in the present example moves downstream, towards its uncoupling position. In this position, the rotor 16 of the electric machine 10 is no longer driven in rotation by the low pressure shaft 2.

[0034] Advantageously, but not limitatively, the movement of the connecting shaft 24 is controlled by an actuator 40 between the coupling position and the uncoupling position.

[0035] An example of an actuator 40 is illustrated in FIG. 2. This example of an actuator 40 comprises a fixed body 41 which is intended to be fixed on a stator of the turbomachine and a movable body 42 sliding inside the fixed body 41. The fixed body 41 is for example in the form of a housing and extends between a first end 41a and a second end 41b along an axis A which is coaxial with the longitudinal axis in the installation situation. A flange 43 extends for example from the first end 41a and radially outwards. The flange 43 is fixed to a flange 44 of a ferrule 45 which is connected to the stator 15 of the electrical machine 10. The ferrule 45 is advantageously centered on the longitudinal axis X. The fixing between the flange 43 of the fixed body 41 and the flange 44 of the ferrule 45 is carried out for example using a bolted connection 51. The latter may comprise threaded rods which extend parallel to the longitudinal axis X. The ferrule 45 comprises, at a first end 45a, a flange 46 which extends radially outwards.The flange 44 is located for example towards a second end 45b opposite the first end 45a along the longitudinal axis X. The flange 46 is secured to a fixing flange 47 of the stator body (at the level of the second end 19) of the electrical machine 10. The fixing is carried out for example using a bolted connection.

[0036] Advantageously, but not limitingly, the ferrule 45 comprises an axial section of truncated cone shape. This configuration makes it possible to reduce the axial size and limits the cantilevered mass of the actuator. The shape of the ferrule 45 also makes it easier to insert and implement the mobile body 42.

[0037] The movable body 42 of the actuator 40 is advantageously, but not limited to, in the form of a rod. The movable body 42 moves in the present example along the longitudinal axis X. The actuator 40 advantageously, but not limited to, comprises a collar 48 which is integral in movement with the movable body 42. The collar 48 is annular and centered on the longitudinal axis X. The movable body 42 comprises at a first end 42a a flange 49 which extends radially and which is fixed to a radial flange 50 of the collar 48 using fixing members 66. The fixing members 66 comprise threaded rods whose axes are here parallel to the longitudinal axis X. Alternatively, the collar 48 may be integral (or formed in one piece) with the movable body 42 of the actuator 40.

[0038] Advantageously, but not limitatively, and as can be seen in FIG. 2, the collar 48 comprises a wall 52 having an axial section of truncated cone shape. The wall 52 comprises at one of its ends 52a, 52b the radial flange 50.

[0039] Still with reference to Figure 2, at least one support member 55 is connected to the movable body 42. This support member 55 is configured so as to come into contact with a stop surface 56 (visible in Figure 3 for example) of the connecting shaft 24 which is capable of driving at least a part of said support member 55 in rotation. The latter is advantageously movable relative to the movable body 42.

[0040] With reference to Figure 3, the support member 55 is preferably, but not limited to, carried by the collar 48 which is integral with the mobile body 42. In particular, the support member 55 is mounted on an arm 57 which is itself, preferably, carried by the collar 48. The arm 57 is advantageously mounted so as to move (advantageously in translation) relative to the mobile body 42. The arm 57 advantageously moves between a retracted position and an active position.

[0041] Advantageously, the collar 48 is provided with an orifice 58 which passes through the wall 52 of the collar 48 transversely on either side.

[0042] Advantageously, the arm 57 extends through the opening 58 of the wall 52. Advantageously, but not limitingly, the arm 57 extends between a first end 57a and a second end 57b. The support member 55 is mounted for example at the first end 57a.

[0043] In the present embodiment, the support member 55 comprises a roller. The latter comprises an inner ring 59a which is secured to the outer surface of the arm 57 and an outer ring 59b which surrounds the inner ring 59a and which is centered on the axis of elongation of the arm 57. Rolling members 59c, here balls, are installed between the inner ring 59a and the outer ring 59b. Advantageously, but not limitingly, the inner ring 59a is locked in translation along the axis of elongation between a nut 60 and an annular extension 61. In such a way alternatively, the support member may comprise an element which bears on the surface of the connecting shaft 24 and pivots without hindering the rotation of the connecting shaft 24 upon first contact. In other words, the support member pivots relative to the connecting shaft and also relative to the movable body 42 (and here relative to the arm 57).

[0044] As can be seen in Figure 3, the bottom 57 comprises a sole 62 formed for example at the second end 57b. The sole 62 comprises a first surface 63 which is defined in a plane perpendicular to the axis of elongation of the arm 47. The first surface 63 is opposite and in contact with an external surface 64 of the collar 48.

[0045] In the example shown, there are at least three support members 55 which are distributed around the longitudinal axis X.

[0046] The connecting shaft 24 comprises, for example, an end wall 65 which is advantageously inclined relative to the longitudinal axis X. Advantageously, the end wall 65 widens from upstream to downstream from the second end 26. In other words, the end wall 65 is frustoconical. The end wall 65 here carries, for example, the abutment surface 56 which is advantageously frustoconical. The end wall 65 is annular and centered on the longitudinal axis X.

[0047] Figure 4 illustrates the connecting shaft 24 in its uncoupled position. In order to terminate the driving of the rotor 16 of the electrical machine by the connecting shaft 24 in the event of necessity (for example a breakdown, a failure, etc.), the movable body 42 of the actuator 40 applies a force to the stop surface 56 of the connecting shaft 24 using the support member 55 (the roller) from upstream to downstream (along the longitudinal axis) which makes it possible to disengage the first dog teeth 28 from the second dog teeth 29. The outer ring 59b of the roller, in contact with the stop surface 56, is driven in rotation and is considered as an indirect contact between the actuator 40 in a stator frame of reference and the connecting shaft 24 which is a rotor. The roller makes it possible to make a transition between the rotor and the stator. In this way, the connecting shaft 24 moves from the coupling position to the uncoupling position. Uncoupling the teeth 28, 29 (i.e. stopping the rotation of the rotor 16) does not prevent the turbomachine from operating.

[0048] With reference to Figure 5, the turbomachine 1 comprises a locking member 70 in the position of the connecting shaft 24 and preferably in the uncoupling position. The locking member 70 is for example a pin or a peg. In particular, the locking member 70 comprises a rod 71 which extends along an axis of revolution B between a first end 71a and a second end 71b. In the installation situation, the axis of revolution B of the locking member 70 is parallel to the radial axis. The locking member 70 is equipped for example with a head 72 at the first end 71a and a sole 73 at the second end 71b.

[0049] The rotor shaft 30 comprises a first orifice 74 which passes through its wall radially on either side. The connecting shaft 24 comprises a second orifice 75 which passes through its wall radially on either side. Optionally, the first orifice 74 is provided at a section 30b of the rotor shaft 30 which extends along the longitudinal axis X. Advantageously, but not limitingly, the section 30b extends radially inside the tight splines 31. The section 30b extends for example parallel to a section 24b of the connecting shaft 24 in which the second orifice 75 is provided. The sole 73 of the locking member 70 is arranged radially outside the section 30b.

[0050] The locking member 70 is advantageously, but not limited to, movable between an unlocking position (shown in FIGS. 1 and 3) and a locking position (shown in FIG. 5). Advantageously, the locking member 70 slides, along the radial axis, at least in the first orifice 74. The head 72 of the locking member 70 is intended to slide and to be housed in the second orifice 75. Preferably, the head 72 is housed in the second orifice 75 of the connecting shaft 24 in the locking position. In this locking position, the first orifice 74 is arranged opposite the second orifice 75. Conversely, the head 72 is outside the second orifice 75 in the unlocking position. The dog teeth 28, 29 are uncoupled when the locking member 70 is in the position of locking and are coupled when the locking member 70 is in the unlocked position.

[0051] According to an optional characteristic, the locking member 70 has a length equal to or greater than the height H1 measured between the external surface of the section 30b and the external surface of the section 24b in the locking position.

[0052] A first elastic element 76 is intended to move the locking member 70 into the locking position. In particular, the rotor shaft 30 comprises a housing 77 in which the first elastic element 76 is housed. The latter is for example a compression spring which extends radially. The first elastic element 76 extends on the one hand around the rod 71 and on the other hand between the head 72 and the sole 73. The housing 77 is advantageously a portion of the first orifice 74 which has a larger axial section.

[0053] Advantageously, but not limitingly, the head 72 of the locking member 70 moves on a frustoconical surface 78 of the connecting shaft 24. In particular, when the connecting shaft 24 moves from the coupling position to the uncoupling position, the head 72 moves (slides) on the frustoconical surface 78 and freely in translation through the first orifice 74 along the radial axis. The frustoconical surface 78 is carried by a frustoconical section 24c (referenced in FIG. 4) of the connecting shaft 24. In the present example, the frustoconical section 24c is advantageously located downstream of the section 24b. When moving from downstream to upstream, the first elastic element 76 compresses in the housing and then decompresses once the head 72 is opposite the second orifice 75. As can be seen in FIG. 3, the first elastic element 76 is not compressed when the connecting shaft 24 is coupled with the low pressure shaft 2.

[0054] The turbomachine 1 comprises a second elastic element 80 which is configured so as to move the connecting shaft 24 towards the coupling position. The second elastic element 80 extends along the longitudinal axis between a first stop surface 81 of the rotor shaft 30 and a second stop surface 82 of the connecting shaft 24. Advantageously, the first stop surface 81 is carried by a first projection 83 which extends radially from a surface external surface of the connecting shaft 24. The second stop surface 82 is carried by a second projection 84 which extends radially from an internal surface of the rotor shaft 30. The first and second stop surfaces 81, 82, the external surface of the connecting shaft 24 and the external surface of the rotor shaft 30 delimit a housing in which the second elastic element 80 is arranged. Optionally, the projections 83, 84 are formed respectively at the sections of the rotor shaft and the connecting shaft 24. The second elastic element 80 is for example a compression spring. The latter is for example in a compressed state when the connecting shaft 24 occupies the uncoupling position (see FIG. 5) and in a decompressed state when the connecting shaft occupies the coupling position (see FIG. 3).

[0055] Figures 6 to 8 illustrate examples of steps for mounting the actuator 40 relative to the stator of the turbomachine 1. In Figure 6, the actuator 40 is at a distance from the electric machine 10 and the components of the turbomachine. The arm 57 occupies the retracted position which makes it easier to fix the actuator 40 to the stator and in particular the stator of the electric machine 15. In this retracted position, the support member 55 is close to the collar 48. The support member 55 is also said to be in a retracted position and is opposite an internal surface 85 of the collar 48. The internal surface 85 is opposite the external surface 64 of the collar 48. In this retracted position, the most radially lower point of the support member 55 delimits the maximum diameter D1a of the support member 55 which is equal to or greater than the maximum diameter D2 of the end wall delimited by the most radially external point.The roller can pass over the end wall 65 to facilitate subsequent assembly and disassembly. The shape of the collar also makes it easier to position the support member in its radially furthest position to facilitate assembly and disassembly of the actuator 40.

[0056] In Figure 7, the fixed body of the actuator 40 is fixed to the stator body of the electrical machine 10. The support member 55 is always in the retracted position which allows it to pass radially above the connecting shaft 24 and in particular the end wall 65 which extends transversely and in this position towards the inside of the collar 48. Advantageously, the support member 55 is retracted only for the time of assembly and disassembly of the actuator 40. The retraction of the support member 55 is facilitated by a removable spacer 87 which is positioned between the sole 62 of each arm 57 and the external surface 64 of the collar 48. We understand that the arm 57 mounted to move relative to the mobile body 42 allows adaptation to all configurations of the connecting shaft 24, and in particular differences in diameters and / or the abutment surfaces 56 which is frustoconical or inclined or has a direction different from the longitudinal axis in this exemplary embodiment.

[0057] In Figure 8, the support member 55 occupies an active position in which it is at a distance from the collar 48. In the active position, the most radially lower point of the transition member 55 delimits the minimum diameter D1 b of the support member which is less than the maximum diameter D2 of the end wall 65 delimited by the most radially external point. The roller can come into abutment against the abutment surface 56 of the end wall 65 of the connecting shaft 24.

[0058] To move from the retracted position to the active position, the spacer 87 is extracted, which allows the sole 62 of the arm 57 to come into contact with the collar 48. For this purpose, a third elastic element 86 is configured to move the arm 57 from the retracted position to the active position. The third elastic element 86 facilitates the return of the support member 55 carried by the arm 57 to the active position. Advantageously, but not limitingly, the third elastic element 86 is housed in a housing formed in the collar 48. The housing is coaxial with the orifice 58 of the collar 48.

[0059] Advantageously, but not limitingly, the ferrule 45 comprises at least one opening 88 which passes through its wall on either side. The opening 88 allows the passage and extraction of the spacer 87 from each arm 57. The opening 88 has a suitable section allowing the passage of one or more spacers. According to an exemplary embodiment, the ferrule 45 comprises several openings corresponding to the number of spacers cooperating with each arm 57 and for the passage of each spacer. Each opening 88 is advantageously arranged opposite a spacer 87 to facilitate the extraction and handling of the spacer. Advantageously, but not limitingly, the or each opening is closed after the extraction of the or each spacer.

[0060] According to an exemplary embodiment, the support member 55, here the roller, is lubricated with grease. Indeed, the support member 55 is located in a second enclosure 89 which also houses the electric machine 10. The second enclosure 89 is distinct from the first enclosure 8. The second enclosure 89 is contained in the cavity 11. The second enclosure 89 is delimited at least in part by the stator 15 of the electric machine 10, the ferrule 45 linked to the actuator 40, and a portion of the connecting shaft 24. There is no lubricant ejected into the second lubrication enclosure. There is only the grease of the rollers.

[0061] With reference to Figure 5, at least one seal 90 (see Figure 1) is provided so as to separate the first lubrication enclosure 8 from the second enclosure 89. The seal 90 is advantageously installed in a groove 91 which is formed in the first projection 83 of the connecting shaft 24 (and in particular of the section 24b of the connecting shaft 24). The groove 91 is for example annular as is the seal 90. The groove 91 has a U-shaped axial section and its opening is arranged opposite a radially internal surface 94 of the section 30b of the rotor shaft 30. The seal 90 is in contact with the radially internal surface 94 of the rotor shaft and preferably of the section 30b.

[0062] The first enclosure 8 is supplied by a lubrication circuit 100 which is connected to a power source (not shown). The lubrication source may be a reservoir. The lubrication circuit 100 comprises a pipe 101 which is formed in a thickness of a portion of the rear end 3 of the low-pressure shaft 2 as illustrated in FIGS. 1 and 3 to 5. The pipe opens into the first lubrication enclosure 8. For this purpose, the pipe 101 opens onto a radial surface 102 of the rear end of the low-pressure shaft from which the second dog teeth 29 extend. The connecting shaft 24 comprises a shaft section 24a which carries a portion of the sliding splines 34. The shaft section 24a comprises, for example, external splines which extend radially outwards and which are intended to cooperate with internal splines of the rotor shaft 30 which extend radially inwards.The external splines and the internal splines form the sliding splines 34. The shaft section 24a comprises an orifice 104 which passes through its wall on either side radially. The orifice 104 is advantageously arranged downstream of the. external splines. Lubricant can flow to this orifice 104 to also lubricate the sliding splines 34.

[0063] Advantageously, but not limitingly, the rear end 3 of the low-pressure shaft 2 comprises an annular skirt 105 which extends axially downstream and which is intended to envelop at least the dog teeth 29. The lubricant at the outlet of the pipe 101 progresses on the internal surface 106 of the skirt 105 which directs it towards the orifice 104. The lubricant can progress towards the rotation bearings 35 of the rotor shaft of the electrical machine 10 as well as towards the rear bearing 6. Advantageously, but not limitingly, the or each rotation bearing 35 is arranged in the first enclosure 8. Such a configuration of the lubrication circuit makes it possible to avoid constraints of arrangement of services outside the first enclosure which implies a saving in mass.

[0064] The lubrication circuit 100 may include passages that are provided to return the lubricant to the supply source.

[0065] The lubricant is preferably oil (in the form of a mist) which makes it possible to lubricate and cool the bearings 35 guiding the rotation of the rotor shaft of the electric machine 10 and the bearing 6 of the low pressure shaft 2 which produce heat.

Claims

Claims [1] Turbomachine (1), in particular for aircraft, comprising: - a low pressure shaft (2) extending along a longitudinal axis (X) to a rear end (3), - a turbomachine stator (4) supporting the rear end (3) of the low pressure shaft (2) by a rear bearing (6), - an electric machine (10), located at the rear of the turbomachine, comprising an electric machine stator (15) fixed to the stator (4) of the turbomachine and an electric machine rotor (16) supported by the stator (4) of the turbomachine via at least one bearing (35), - a connecting shaft (24) extending the low pressure shaft (2) rearwardly along the longitudinal axis and capable of driving the electric machine rotor (16) in rotation in a disconnectable manner via the low pressure shaft, and - an actuator (40) configured to move the connecting shaft (24) into a decoupling position and comprising a fixed body (41) connected to the stator of the turbomachine, the actuator (40) comprises at least one support member (55) connected to a movable body (42) relative to the fixed body (41) of the actuator (40) and intended to come into contact with a stop surface (56), oriented in a direction different from the longitudinal axis (X), and carried by the connecting shaft (24) which is capable of driving said support member (55) in rotation relative to the movable body (42), characterized in that the support member (55) comprises at least one part mounted free to rotate on an arm (57) which is mounted on the movable body (42), the arm (57) being capable of moving relative to the movable body (42) between a retracted position and an active position. [2] Turbomachine (1) according to the preceding claim, characterized in that the connecting shaft (24) comprises at a first end first dog teeth (28) which are intended to mesh or disengage with second dog teeth (29) located at the rear end (3) of the low pressure shaft (2). [3] Turbomachine (1) according to any one of the preceding claims, characterized in that the arm (57) is carried by a collar (48) which is fixed to one end of the movable body (42) and which is centered on the longitudinal axis (X). [4] Turbomachine (1) according to one of the preceding claims, characterized in that it comprises a locking member (70) configured so as to lock the connecting shaft (24) in its coupling position. [5] Turbomachine (1) according to the preceding claim, characterized in that the locking member (70) is mounted to move radially relative to a rotor shaft (30) of the electrical machine (10) and comprises a head (72) intended to slide and to be housed in an orifice (75) of the connecting shaft (24). [6] Turbomachine (1) according to one of the preceding claims, characterized in that an elastic element (80) is configured so as to move the connecting shaft (24) into a coupling position with the low pressure shaft (2), the elastic element (80) extending along the longitudinal axis (X) between a first stop surface (81) of the electric machine rotor (16) and a second stop surface (82) of the connecting shaft (24). [7] Turbomachine (1) according to claim 3 or claim 3 combined with any one of claims 4 to 6, characterized in that in the retracted position the support member (55) is close to the collar (48) and in the active position the support member (55) is at a distance from the collar (48). [8] Turbomachine (1) according to the preceding claim, characterized in that an elastic element (86) is configured so as to move the arm (57) from the retracted position to an active position. [9] Turbomachine (1) according to one of the preceding claims, characterized in that the rear bearing (6) is arranged in a first lubrication enclosure (8) and in that it comprises a lubrication circuit (100) comprising a pipe (101) which is formed in a thickness of a portion of the rear end (3) of the low pressure shaft (2) and which opens into the first enclosure (8). [10] Turbomachine (1) according to the preceding claim, characterized in that the electric machine (10) and the support member (55) are contained in a second enclosure (89) which is separate from the first lubrication enclosure (8), the first enclosure (8) and the second enclosure (89) being separated at least in part by a seal (90). [11] T urbomachine (1) according to claim 5 and one of claims 9 and 10, characterized in that the rotor shaft (30) of the electric machine (15) is supported by at least one rotation bearing (35) which is arranged in the first enclosure (8). [12] Turbomachine (1) according to one of the preceding claims, characterized in that the connecting shaft (24) comprises an end wall (65) which flares from upstream to downstream from one end (26), the end wall (65) carrying the stop surface (56).

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