Turbomachine including a sectored casing

Abstract

The invention relates to a turbomachine extending in a longitudinal direction, comprising a casing including a concentric outer and inner shell, and radial arms connecting the outer shell to the inner shell. This turbomachine is traversed by a hot primary flow circulating longitudinally between the two shells and by a cold secondary flow circulating longitudinally around the outer shell. The casing comprises electrically conductive sectors (18a, 18b) rigidly joined to each other by electrically insulating fastening members (34a, 36a). Each sector (18a, 18b) comprises a portion of the outer shell (19a) connected to a portion of the inner shell (21a) by a radial arm. (See Figure 5 for abbreviations.)

Description

Title of the invention: Turbomachine comprising a sectored casing technical field

[0001] The invention relates to the electrical connection of an electrical machine within the framework of the integration of this electrical machine into a turbomachine. PREVIOUS STATE OF THE ART

[0002] A turbofan engine of the turbofan type comprises an inlet sleeve into which air is admitted before being drawn in by the blades of a fan. After passing through the fan, the air splits into a central hot primary flow and a cold secondary flow that surrounds the primary flow.

[0003] The primary airflow then passes through a first compressor located after the blower while the secondary flow is propelled backwards to directly generate thrust by being blown around the primary flow.

[0004] The primary flow then passes through a second compression stage before reaching a combustion chamber. After combustion, this primary flow expands in a high-pressure turbine and then in a low-pressure turbine before being expelled towards the rear of the turbojet engine.

[0005] Each turbine comprises one or more stages, each comprising a series of radial blades regularly spaced around an axis of rotation of the turbojet.

[0006] Integrating an electric machine into such a turbojet engine makes it possible, for example, to drive the central shaft carrying the fan blades and those of the first compression stage and the low-pressure turbine. Such integration can also be considered to drive the high-pressure casing that carries the blades of the second compression stage and the low-pressure turbine, or to drive other components.

[0007] Such integration is also implemented in existing turbomachines, the electric machine then being a current generator enabling the delivery of an electrical supply for receivers located outside the turbomachine.

[0008] In general, such integration is problematic with regard to the connection of the electrical machine, because it is located in a very central region of the turbojet engine.

[0009] In patent document FR2922265, the electrical connection of an electric machine located immediately downstream of the blower is ensured by electrical cables housed in radial arms of a corresponding casing that pass through the primary flow. Patent documents FR3087819 and WO2020084225 disclose similar solutions with regard to the electrical connection.

[0010] Since such radial arms are also traversed by fuel and oil supply lines, and / or auxiliary lines, the addition of electrical cables constitutes an integration constraint that is detrimental. This results from the fact that such cables have a large cross-section due to the high current they carry and the significant insulation thickness required by the high voltage to which they are subjected.

[0011] In this context, the object of the invention is to provide a solution to facilitate the connection of an electrical machine in a turbomachine. Description of the invention

[0012] To this end, the invention relates to a turbomachine extending in a longitudinal direction, comprising a casing including an outer and an inner concentric shell, and radial arms connecting the outer shell to the inner shell, this turbomachine being traversed by a hot primary flow circulating longitudinally between the two shells and by a cold secondary flow circulating longitudinally around the outer shell, this casing comprising electrically conductive sectors rigidly joined to each other by electrically insulating fastening members, each sector comprising a portion of outer shell connected to a portion of inner shell by a radial arm.

[0013] With this solution, the electrical connection phases of the turbomachine pass directly through the metallic material of the casing sectors, so that it is not necessary to provide connecting cables, which makes it possible to significantly simplify the integration and assembly of an electrical machine in the turbomachine.

[0014] The invention also relates to a turbomachine thus defined, comprising electrically insulating longitudinal bars interposed each between two longitudinal edges of two circumferentially contiguous ferrule portions to secure them to each other in a sealed manner.

[0015] The invention also relates to a turbomachine as defined, comprising electrically insulating arcs each fixed to two circumferential edges of two circumferentially contiguous ferrule portions to secure them to each other.

[0016] The invention also relates to a turbomachine thus defined, comprising fastening elements each including a longitudinal bar and two arcs each fixed to one end of the bar.

[0017] The invention also relates to a turbomachine as defined above, in which the fastening members are fixed to the portions of the ferrules by riveting or bolting through holes formed in these fastening members and through holes formed in the circumferential edges of the portions of the ferrules.

[0018] The invention also relates to a turbomachine as defined above, in which Each arc is fixed to one end of the barrette by bolting or riveting through holes formed in the arc and holes formed at the ends of the barrettes.

[0019] The invention also relates to a turbomachine thus defined, in which the circumferential edges of the ferrule portions extend in planes normal to the longitudinal axis.

[0020] The invention also relates to a turbomachine as defined above, comprising at least one longitudinal bar having longitudinal edges provided with grooves in which fit the longitudinal edges of the two portions of ferrules between which this longitudinal bar is interposed.

[0021] The invention also relates to a turbomachine as defined above, in which the fastening members are made of ceramic material.

[0022] The invention also relates to a turbojet comprising a turbomachine as defined above. Brief description of the drawings

[0023] Fig. 1 is a longitudinal cross-sectional view of a turbofan engine;

[0024] Fig. 2 is a perspective view of an inter-turbine housing according to the invention;

[0025] Figure 3 is a perspective view of the sectors of an inter-turbine housing according to the invention;

[0026] Figure 4 is a perspective view of a sector of the inter-turbine casing according to the invention;

[0027] Fig. 5 is a perspective view of the assembly of two sectors of the inter-turbine housing according to the invention;

[0028] Fig. 6 is a partial view showing the fitting of a longitudinal bar with a longitudinal edge of a portion of an internal ferrule.

[0029] DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0030] In [Fig.1], a turbofan engine 1 has an inlet sleeve 2 into which air is admitted before being sucked in by the blades of a fan 3. After passing through the fan region, the air splits into a central primary flow and a secondary flow which surrounds the primary flow.

[0031] The primary airflow then passes through a first compressor 4 located immediately after the blower 3 while the secondary flow is propelled backwards to directly generate additional thrust by being blown around the primary flow.

[0032] The primary flow then passes through a second compression stage 6, before reaching a chamber 7 where combustion takes place, after injection and vaporization of a fuel. After combustion, this primary flow expands in a high-pressure turbine 8 and then in a low-pressure turbine 9 to rotate the compression stages. and the fan, before being expelled towards the rear of the turbojet to generate thrust.

[0033] Each turbine comprises a series of stages, each with a set of radially oriented blades regularly spaced around a central rotating shaft. This central shaft, extending along a longitudinal axis AX, carries the rotating elements of the blower 3, the first compressor 4, and the low-pressure turbine 9. It is surrounded by a so-called high-pressure body, rotating independently of this central shaft, and carrying the blades of the second compression stage 6 and those of the high-pressure turbine 8.

[0034] The path of the primary flow is delimited by several housings which are joined and fixed to each other along the longitudinal axis, such as the inlet housing 11, the inter-compressor housing 12, the inter-turbine housing 13, and the exhaust housing, which surround the central shaft and / or the high-pressure body.

[0035] Each housing comprises an inner and an outer concentric ferrule with radial arms connecting the inner ferrule to the outer ferrule, so that the hot primary flow circulates between these ferrules to pass through such a housing.

[0036] Adding an electric machine to such a turbomachine, to drive the central shaft or the high-pressure body, requires integrating this machine into the central part of the turbojet, that is to say in the internal space delimited by the internal shells of the casing.

[0037] Thus, such integration requires, on the one hand, providing space in the internal region to accommodate the electric machine, but on the other hand, providing an electrical supply system for this machine, given that the electrical supply source is located outside the turbomachine.

[0038] The idea behind the invention is to provide that the different phases of the electrical supply pass through the casing itself, instead of being transferred via conventional power cables.

[0039] For this purpose, the casing is made up of several sectors electrically isolated from each other, so that each sector is traversed by the electrical supply of one of the phases of the electrical connection.

[0040] In [Fig. 2], the inter-turbine housing 13 comprises an outer ring 15 surrounding an inner ring 16 which is concentric with it, these rings being here approximately conical in shape. These rings 15, 16 are connected to each other by six radial arms 17a-17f which are hollow so as to allow passage for mechanical components, fuel supplies or other elements.

[0041] This housing 13 is formed of six electrically conductive sectors 18a-18f, which appear alone on the [Fig.3], and which are joined together by electrically insulating fastening elements.

[0042] As can be seen in [Fig.4], sector 18a comprises an external ferrule portion 19a and an internal ferrule portion 21a as well as the radial arm 17a by which these two ferrule portions are rigidly joined to each other.

[0043] The portion 19a has a shape corresponding to an angular sector of the external ferrule 15, being delimited by two substantially straight longitudinal edges 22a, 23a and by two circumferential edges 24a and 26a in the shape of arcs of circles, this portion 19a thus having on the whole an approximately trapezoidal contour.

[0044] The longitudinal edges 22a and 23a each extend in a plane containing the axis AX, and the circumferential edges 24a, 26a have the shape of arcs of circles centered on this axis AX. As can be seen in this [Fig. 4], each circumferential edge 24a, 26a has the shape of a portion of a flat ring extending in a plane normal to the axis AX and is provided with a series of holes 27 which are regularly spaced from each other around the axis AX.

[0045] Each of these edges constitutes a rim folded at a right angle to the main wall 25a of the portion 19a, in a direction away from the axis AX, this main wall constituting the body of this portion 19a and having the shape of an angular sector of a truncated cone.

[0046] Similarly, portion 21a has a shape corresponding to an angular sector of the internal ferrule 16, being delimited by two straight longitudinal edges 28a, 29a, and by two circumferential edges 31a, 32a in arcs of circles, this portion 21a also having on the whole an approximately trapezoidal contour.

[0047] The edges 28a and 29a each extend in a plane containing the axis AX, and the edges 31a and 32a are centered on the axis AX. These edges 31a and 32a are also folded edges bent at right angles to the main wall 33a of portion 21a, and they are also provided with regularly spaced holes 27. Unlike portion 19a, the circumferential edges 31a and 32a of portion 21a are folded in the direction of the axis AX.

[0048] The other sectors of the housing 13, namely sectors 18b-18f, have a general structure and geometry identical to sector 18a, two sectors being able to differ from each other essentially by the arrangement of inserts or fixing holes for turbojet components not shown.

[0049] As can be seen in [Fig.5], the two sectors 18a and 18b are connected to each other by an external fixing member 34a which rigidly secures their portions of external ferrules 19a and 19b to each other, and by an internal fixing member 36a which rigidly secures their portions of internal ferrules 21a and 21b to each other.

[0050] The external fastening member 34a comprises a bar 37a having a tongue-like shape with an essentially rectangular contour, as well as a first arch 38a and a second arch 39a. The first arch 38a is rigidly fixed at its center to a end of bar 37a, and the second arc 39a is rigidly fixed at its center to the opposite end of bar 37a.

[0051] Each arc has a crown-like shape extending in a plane normal to the axis of the bar 37a and having an angular extent slightly less than that of an external portion 19a or 19b, and it has holes 41 regularly spaced from each other. The width of an arc along a plane normal to that of the bar 37a is slightly less than the width of the edges 24a, 26a, 24b, 26b of the external portions 19a and 19b in a radial direction with respect to the axis AX, and these arcs 38a and 39a have radii substantially identical to the radii of the edges, so as to be able to be applied against these edges.

[0052] When the fastening member 34a is installed, the bar 37a extends between the longitudinal edges 23a and 22b to ensure optimal sealing between them. One half of the first arc 38a is then applied against one half of the circumferential edge 24a and its other half is applied against one half of the circumferential edge 24b to secure them together, being fixed to them by bolts or rivets passing through holes 27 and 4L. Similarly, one half of the second arc 39a is then applied against the circumferential edge 26a and its other half is applied against one half of the circumferential edge 26b to secure them together, being fixed to them by bolts or rivets passing through holes 27 and 4L.

[0053] In practice, the positioning of the external fixing member 34a consists of placing it radially under portions 19a and 19b by positioning its bar 37a opposite the space separating the longitudinal edges 23a and 22a, and moving it radially away from the axis AX. This movement allows the bar 37a to be fitted between the edges 23a and 22b while placing its arcs 38a and 39a respectively against the external faces of the circumferential edges 24a and 24b and against the external faces of the circumferential edges 26a and 26b.

[0054] When the component 34a has been positioned, its arcs can be fixed to the portions 19a and 19b, by bolting or riveting through the holes 27 and 41 provided for this purpose.

[0055] Similarly, the internal portions 21a and 21b are fixed by the internal fixing member 36a, which also comprises a rectangular tongue-shaped bar 43a, as well as a first arc 44a and a second arc 46a. The first arc 44a is rigidly fixed at its center to one end of the bar 43a, and the second arc 46a is rigidly fixed at its center to the opposite end of this bar 43a.

[0056] Each arc has a crown portion shape extending in a plane normal to the axis of the bar 43a with an angular extent slightly less than that of an internal portion 21a or 21b, and it has regularly spaced holes 41. the width of an arc is slightly less than that of the edges 31a, 32a, 31b of the internal portions 21a and 21b, and these arcs 44a and 46a have radii corresponding to those of the edges, to be applied against the latter.

[0057] When the fastening member 36a is in place, the bar 43a extends between the longitudinal edges 29a and 28b of the internal portions to form a watertight joint. One half of the first arc 44a is then applied against one half of the circumferential edge 31a and its other half against one half of the circumferential edge 24b, being fixed by bolting or riveting through the holes 27 and 41. One half of the second arc 46a is then against the circumferential edge 32a and its other half is against one half of the corresponding circumferential edge of the portion 21b, being fixed by bolting or riveting through the holes 27 and 41.

[0058] In practice, the positioning of the internal fixing member 36a consists of placing it radially on the portions 21a and 21b by placing its bar 43a opposite the space separating the longitudinal edges 29a and 28b, and bringing it closer to the axis AX to fit this bar 43a between the edges 29a and 28b while placing its arcs 44a and 46a respectively against the external faces of the circumferential edges 31a and 31b and against the external faces of the opposite circumferential edges of the portions 21a and 21b.

[0059] When the component 36a has been positioned, its arcs can be fixed to the internal portions 21a and 21b by bolting or riveting through holes 27 and 4L

[0060] As can be seen in [Fig.5], each fastening member comprises a bar at the ends of which the two arcs are fixed by bolting or riveting through corresponding holes 41 formed in these arcs and other holes formed at the ends of the bar.

[0061] In the example of [Fig. 5], the fastening elements are pre-assembled before being attached to the ferrule portions, which they then secure together. However, it is also possible to proceed in stages, starting with unpre-assembled fastening elements.

[0062] In this case, the arcs of a fastening member are first fixed to the circumferential edges of the ferrule portions to secure them to each other, after which the longitudinal bar of this member can be inserted between the longitudinal edges of these ferrule portions before being fixed by its ends to the two arcs.

[0063] Moreover, and as schematically illustrated in [Fig.6], the longitudinal bars advantageously have their edges arranged to optimize the sealing they provide between the two portions of ferrules that they join.

[0064] More specifically, the bar 43a visible in [Fig. 6] has a groove at each of its longitudinal edges, these grooves being identified by 47a and 48a. As can be seen in [Fig. 6], the groove 47a has a thickness corresponding to the thickness of the edge 29a of the ferrule portion 21a, which allows this edge to be fitted into this groove when the assembly is mounted, so as to ensure optimal sealing of the junction between the bar and the ferrule portion. Similarly, the groove 48a has a thickness corresponding to that of the edge 28b of the ferrule portion 21b to allow this edge to fit into it.

[0065] In addition to the fastening elements, the housing can be equipped with metal bands to reinforce the mechanical strength provided by these fastening elements. In this case, these additional bands, not shown in the figures, are supported only by the fastening elements, so as to maintain satisfactory electrical insulation between the different sections of the housing.

[0066] Generally, the sectors of the housing are made of metal alloy to be electrically conductive, and the fixing members which are electrically insulating are advantageously made of electrically insulating ceramic material both with regard to their arcs and their longitudinal bars.

[0067] The ceramic used can be the so-called Ox Ox ceramic, known as Alumina A12O3, or refractory glass containing 80% SiO2 and various compounds such as B2O3, Na2O, A12O3. Another ceramic such as Silicon Nitride Si3N4 can also be used.

[0068] In the example of the figures, the sectorized housing is an inter-turbine housing which has six sectors, to connect an electric machine which can be a drive motor for the central shaft or the high-pressure body, or be a current generator driven by the central shaft or the high-pressure body.

[0069] This housing comprises six sectors to ensure the connection of three electrical phases, each phase passing, for example, in parallel through two diametrically opposed sectors around the longitudinal axis. A single phase can also be split to correspond to two separate connections, one of which is provided as a redundancy in case of failure of the other phase.

[0070] Generally speaking, the number of sectors is adapted to the configuration of the electrical machine, for example, the casing could have two or four sectors in the case of an electrical machine with two phases instead of three.

[0071] Furthermore, the invention has been described for the case of an inter-turbine casing but it applies to any turbomachine casing, such as for example an inlet casing, an intermediate casing, an inter-compressor casing, or other.

Claims

Demands

1. A turbomachine extending along a longitudinal direction (AX), comprising a casing (13) including a concentric outer shell (15) and inner shell (16), and radial arms (17a-17f) connecting the outer shell (15) to the inner shell (16), this turbomachine being traversed by a hot primary flow circulating longitudinally between the two shells (15, 16) and by a cold secondary flow circulating longitudinally around the outer shell (15), this casing (13) comprising electrically conductive sectors (18a-18f) rigidly joined to each other by electrically insulating fastening members (34a, 36a), each sector (18a-18f) comprising a portion of outer shell (19a) connected to a portion of inner shell (21a) by a radial arm (17a-17f), the outer shell portions (19a) being joined together by electrically insulating external fastening elements (34a),the internal ferrule portions (21a) being joined together by electrically insulating internal fastening elements (36a).

2. Turbomachine according to claim 1, comprising electrically insulating longitudinal bars (37a, 43a) interposed each between two longitudinal edges (23a, 22b; 29a, 28b) of two circumferentially contiguous shell portions (19a, 19b; 21a, 21b) to secure them to each other in a sealed manner.

3. Turbomachine according to claim 1, comprising electrically insulating arcs (38a, 39a; 44a, 46a) each fixed to two circumferential edges (24a, 24b, 26a, 26b; 31a, 31b, 32a) of two circumferentially contiguous ferrule portions (19a, 19b; 21a, 21b) to secure them to each other.

4. Turbomachine according to claims 2 and 3, comprising fastening members (34a, 36a) each including a longitudinal bar (37a, 43a) and two arcs (38a, 39a; 44a, 46a) each fixed to one end of the bar (37a, 43a).

5. Turbomachine according to claim 4, wherein the fastening members (34a, 36a) are fixed to the ferrule portions (19a, 19b; 21a, 21b) by riveting or bolting through holes (41) formed in these fastening members (34a, 36a) and through holes (27) formed in the circumferential edges (24a, 24b, 26a, 26b; 31a, 31b, 32a) of the ferrule portions (19a, 19b; 21a, 21b).

6. Turbomachine according to claim 4, wherein each arc (38a, 39a; 44a, 46a) is fixed to one end of a bar (37a, 43a) by bolting or riveting through holes (41) formed in the arc and holes formed at the ends of the bars (37a, 43a).

7. Turbomachine according to claim 5, wherein the circumferential edges (24a, 24b, 26a, 26b; 31a, 31b, 32a) of the ferrule portions (19a, 19b; 21a, 21b) extend in planes normal to the longitudinal axis (AX).

8. Turbomachine according to claim 2, comprising at least one longitudinal bar (37a, 43a) having longitudinal edges provided with grooves (47a, 48a) into which fit the longitudinal edges (23a, 22b; 29a, 28b) of the two portions of ferrules (19a, 19b; 21a, 21b) between which this longitudinal bar (37a, 43a) is interposed.

9. Turbomachine according to claim 1, wherein the fastening members (34a, 36a) are made of ceramic material.

10. Turbojet comprising a turbomachine according to one of the preceding claims.

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