CRANKCASE FOR AN AIRCRAFT TURBOMACHINE

Abstract

Casing (8) for a turbomachine (1), particularly for aircraft, the casing (8) comprising: - at least one annular body - sleeves (26) adapted to receive blade roots (18a), and - connecting plates (40) for the sleeves (26), the plates (40) each being mounted between two adjacent sleeves (26), each of the plates (40) having a first circumferential end (40a) fixed to one of the two adjacent sleeves (26) and a second opposite circumferential end (40b) fixed to a second of the two adjacent sleeves (26). Figure for the abbreviation: Figure 4

Description

Title of the invention: Casing for an aircraft turbomachine Technical field of the invention

[0001] The invention relates to the field of housings for turbomachinery, in particular aircraft.

[0002] The invention relates in particular to the field of housings carrying fixed (stator) blades, in particular with variable pitch angle, also known by the English acronym OGV for "Outlet Guided Varies". Technical background

[0003] Among aircraft turbomachinery, there are unducted single-fan turbomachinery. This type of turbomachine offers high propulsive efficiency compared to ducted single-fan turbomachinery.

[0004] This type of turbomachine typically extends around and along a longitudinal axis and comprises, from upstream to downstream in the direction of the gas flow along this longitudinal axis, an unshod blower, a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine and a low-pressure turbine.

[0005] In contrast to enclosed fan turbomachines, the unenclosed fan turbomachine does not include a fan casing surrounding the fan.

[0006] The low pressure turbine is conventionally connected to the low pressure compressor and the blower by a low pressure shaft, and the high pressure turbine is connected to the high pressure compressor by a high pressure shaft.

[0007] The blower compresses an airflow. The compressed airflow splits into a primary airflow flowing in a primary channel of the turbomachine and a secondary airflow flowing in a secondary channel surrounding the primary channel. The primary airflow is compressed in the compressors and then burned in the combustion chamber. The combustion gases pass through the turbines, which then drive the blower and the low-pressure compressor.

[0008] Furthermore, the unshrouded turbomachine typically includes an air inlet casing arranged axially between the fan and the low-pressure compressor. The inlet casing is typically axially connected to a casing of the low-pressure compressor located downstream. The inlet casing includes, in a known manner, an inner shell centered on the longitudinal axis and an outer shell arranged coaxially around the inner shell. The outer shell internally delimits a portion of the secondary vein and the internal ferrule externally delimits a part of the primary vein.

[0009] To improve the performance of the turbomachine, the inlet casing carries fixed vanes, also known by the English acronym OGV for "Outlet Guided Varies". Such vanes are regularly spaced around the longitudinal axis and compress the secondary airflow. These fixed vanes typically have a variable pitch angle, which allows their pitch angle to be adapted to the turbomachine's operating speeds.

[0010] In order to connect the blades to the inlet housing, support sleeves for these fixed blades are provided, which are regularly distributed around the longitudinal axis and are connected to the aforementioned outer ferrule. Each support sleeve typically comprises a hollow annular wall into which the fixed blades are inserted for their attachment to the inlet housing.

[0011] However, the integration of these sleeves on the inlet casing presents many challenges: they must withstand stresses without being too heavy or transmitting too much stress to the casing; they must be rigid enough to hold the blades well, they must not be too bulky in the small space between the casing and the external vein, and finally they must ideally allow for the attachment of several pieces of equipment such as auxiliary equipment, jacks, panels, etc.

[0012] There is therefore a need to provide a housing for an aircraft turbomachine, comprising variable-angle blade support sleeves, which are in particular compact and have optimal load transfer. Summary of the invention

[0013] To this end, the invention proposes a housing for a turbomachine, in particular for aircraft, the housing comprising:

[0014] - at least one annular body extending around a first axis,

[0015] - sleeves suitable for receiving blade feet, the sleeves being distributed around of the first axis, each sleeve having an annular wall extending around a second axis oriented radially with respect to the first axis, each sleeve being connected to the body by a first radial link with respect to the first axis and by a second radial link with respect to the first axis, the first and second links being diametrically opposed and situated one behind the other along the first axis, and

[0016] - connecting plates for the sleeves, the plates being distributed around the first axis and each being mounted between two adjacent sleeves, each of the plates having a first circumferential end fixed on a first of the two adjacent sleeves and a second opposite circumferential end fixed on a second of the two adjacent sleeves.

[0017] By "radial connection" is meant a connection involving at least two bearing surfaces extending in a plane parallel to the first axis and cooperating together.

[0018] Thanks to this double radial connection linking each sleeve to the housing body, the distribution of forces is improved. Furthermore, the axial arrangement of the two connections is particularly well-suited to resisting the forces associated with the ingestion of a foreign body into the turbomachine.

[0019] Also, the size of the casing is reduced, which facilitates the passage of the servicing.

[0020] Finally, optimizing the distribution of forces in the sleeve makes it possible to reduce the deformation of the housing during operation.

[0021] Another advantage of the invention is obtained by connecting the sleeves with plates. Several functions can be attributed to these plates, including:

[0022] - the plates provide a mechanical connection and a transmission of forces between the sleeves; thus, in operation, in the event of ingestion of a foreign body such as a bird for example, the forces associated with the impact of the bird on one of the blades can be transmitted to the casing by the radial links but also to the adjacent sleeves via the plates,

[0023] - the plates stiffen the sleeves while limiting the increase in mass of the crankcase,

[0024] - the plates can be used for attaching equipment such as an actuator control of the angular adjustment of the blades,

[0025] - the plates can be used to fix servicing lines that run along the casing and the first axis,

[0026] - the plates can be used to fix covers extending around the casing,

[0027] - etc.

[0028] The invention may comprise one or more of the following features, taken individually or in combination with each other: - each of the plates includes a rectangular or trapezoidal peripheral contour, the said first and second circumferential extremities being formed by opposite sides of this contour; - the plates are fixed to the sleeves by screws or bolts; - said first and second circumferential ends each include at least two first holes for the passage of screws or bolts, these first holes being aligned with second holes in the sleeves suitable for receiving the screws or bolts; - at least some of the plates include a hollowed-out central part; - the plates are of at least two or three different types, the plates of each type being identical to each other and different from the plates of each other type; - the plates of the first type have an angular extent around the first axis which is different from the plates of each other type; - the housing further includes an actuator configured to control the angular positioning of said blades, and in that at least one of the plates includes a mounting housing for this actuator; - the actuator extends parallel to the first axis; - the housing includes at least one annular flange extending in a plane perpendicular to the first axis and through which the actuator passes; - the casing further includes covers which extend around the first axis and the annular body, each of the covers having an opening aligned radially with one of the sleeves for the passage of the corresponding blade foot, the covers being fixed to the plates by spacers extending radially between the covers and the plates; - each of the spacers comprises a radially internal end fixed to one of the plates, for example in its middle, and a radially external end fixed to two adjacent covers of said covers, and in particular to circumferential ends opposite these two adjacent covers; - the casing also includes servitudes such as cables or pipes, these servitudes extending parallel to the first axis and being fixed to at least one of the plates.

[0029] The invention also relates to a turbomachine for an aircraft, comprising a casing according to any one of the preceding characteristics, and blades, in particular with variable pitch angle, the feet of which are engaged in the sleeves of the casing. Brief description of the figures

[0030] Other features and advantages will become apparent from the following description of a non-limiting embodiment of the invention with reference to the accompanying drawings in which:

[0031] [Fig-1] [Fig.1] is a schematic axial cross-sectional representation of a half- aircraft turbomachine;

[0032] [Fig.2] [Fig.2] is a schematic representation of part of a housing according to the invention comprising first and second ferrules connected to a blade support sleeve;

[0033] [Fig.3] [Fig.3] is a perspective view of a sleeve fitted to the housing of the [Fig.2];

[0034] [Fig.4] [Fig.4] is a partial perspective view of a housing according to the invention comprising sleeves connected together by plates according to an embodiment of the invention;

[0035] [Fig.5] [Fig.5] is a view similar to that of [Fig.4],

[0036] [Fig.6] [Fig.6] is a perspective view of one of the plates of the housing of [Fig.4],

[0037] [Fig.7] [Fig.7] is a perspective view of another of the plates of the crankcase of the [Fig.4]

[0038] [Fig.8] [Fig.8] is a perspective view of another of the plates of the housing of [Fig.4],

[0039] [Fig.9] [Fig.9] is a perspective view of two sleeves and a connecting plate for these two sleeves, seen from above,

[0040] [Fig. 10] [Fig. 10] is another perspective view of the two sleeves and the connecting plate of these two sleeves of [Fig. 9], seen from above,

[0041] [Fig. 11] [Fig. 11] is another partial perspective view of the housing of [Fig. 4] with additional covers, and

[0042] [Fig. 12] [Fig. 12] is a larger scale view of part of [Fig. 11]. Detailed description of the invention

[0043] An example of a turbomachine 1 is illustrated in [Fig. 1]. The turbomachine 1 extends around and along a first axis X.

[0044] In the remainder of the application, unless otherwise indicated, the terms "longitudinal", "longitudinally", "axial", "axially", "radial", "radially", are understood to be in relation to the first X axis of the turbomachine 1.

[0045] The terms "exterior", "interior" are understood in relation to the distance of the first X axis along a radial axis.

[0046] The terms "upstream" and "downstream" are understood with respect to the circular direction of an airflow F in the turbomachine 1 along the first axis X.

[0047] The turbomachine 1 comprises from upstream to downstream a blower 2, a low pressure compressor 3, a high pressure compressor 4, a combustion chamber 5, a high pressure turbine 6, a low pressure turbine 7.

[0048] The fan 2 comprises movable blades 2a regularly distributed around the first axis X. The blades 2a are free to rotate about this first axis X. Advantageously, the blades 2a have a variable pitch angle. They are connected to a pitch-changing system 2b to vary the pitch angle of these blades 2a according to the operating conditions of the turbomachine 1.

[0049] The blower 2 allows the intake of an airflow F which, downstream of the blower 2, splits into a primary airflow Fl and a secondary airflow F2. The primary airflow Fl flows in an annular primary vein vl and the secondary airflow F2 flows into a secondary vein v2 which is annular and surrounds the primary air vein vl.

[0050] The primary airflow Fl is compressed within the low pressure and high pressure compressors 3, 4. Then the primary airflow Fl is mixed with a fuel within the combustion chamber 5. The gases from the combustion flow into the high pressure and low pressure turbines 6, 7.

[0051] The secondary airflow F2 flows into the secondary vein v2 and provides propulsion.

[0052] The turbomachine 1 further comprises an upstream casing 8 arranged downstream of the blower 2.

[0053] The turbomachine 1 further advantageously comprises an inter-compressor casing 9 arranged axially between the low and high pressure compressors 3, 4, an inter-turbine casing 10 arranged axially between the high and low pressure turbines 6, 7 and an exhaust casing 11 of the gases located downstream of the low pressure turbine 7.

[0054] The turbomachine 1 further comprises a low pressure shaft 12 centered on the first axis X and a high pressure shaft 13 arranged coaxially around the low pressure shaft 12.

[0055] The low pressure shaft 12 mechanically connects the low pressure compressor 3 to the low pressure turbine 7 and the high pressure shaft 13 mechanically connects the high pressure compressor 4 to the high pressure turbine 6.

[0056] Advantageously, the turbomachine 1 further comprises a blower shaft 14 connecting the blower 2 to the low-pressure shaft 12, in particular via a mechanical speed reducer 15.

[0057] The blower shaft 14 is guided in rotation by a first bearing 16a. The first bearing 16a is, for example, a double ball bearing. The first bearing 16a is, for example, arranged between the upstream housing 8 and the blower shaft 14.

[0058] The low-pressure shaft 12 is guided in rotation upstream by second and third bearings 16b, 16c. The second and third bearings 16b, 16c are ball and / or roller bearings. The second bearing 16b is, for example, arranged between the upstream housing 8 and the low-pressure shaft 12. The third bearing 16c is, for example, arranged between the inter-compressor housing 9 and the low-pressure shaft 12.

[0059] The low-pressure shaft 12 is guided in rotation downstream by a fourth bearing 16d and a fifth bearing 16e. This fourth bearing 16d is, for example, a roller bearing. The fourth bearing 16d is, for example, located between the inter-turbine housing 10 and the low-pressure shaft 12, and the fifth bearing is, for example, located between the exhaust housing 11 and the low-pressure shaft 12.

[0060] The high-pressure shaft 13 is guided in rotation upstream by a sixth bearing 16f, for example of the double type, and downstream by a seventh bearing 16g. The sixth and The seventh bearings 16f and 16g are, for example, roller and / or ball bearings. The sixth bearing 16f is, for example, located between the inter-compressor housing 9 and the high-pressure shaft 13, and the seventh bearing 16g is, for example, located between the inter-turbine housing 10 and the high-pressure shaft 13.

[0061] In order to allow optimal lubrication of the bearings, the turbomachine 1 further includes lubrication chambers in which said bearings for the rotational guidance of the shafts are arranged.

[0062] The turbomachine 1 includes for example an upstream enclosure 17a in which the first and second bearings 16a, 16b and the speed reducer 15 are arranged. The upstream enclosure 17a is for example located in the upstream casing 8.

[0063] The turbomachine 1 may include an intermediate housing 17b in which the third and sixth bearings 16c, 16f are arranged. The intermediate housing 17b is, for example, located in the inter-compressor casing 9.

[0064] The turbomachine 1 may include a first downstream chamber 17c in which the fourth and seventh bearings 16d, 16g are arranged, and a second downstream chamber 17d in which the fifth bearing 16e is arranged. The first downstream chamber 17c is, for example, located in the inter-turbine casing 10 and the second downstream chamber 17d is, for example, located in the exhaust casing 11.

[0065] The number of bearings and enclosures may vary depending on the configuration of the turbomachine 1.

[0066] According to the invention, the turbomachine 1 further comprises fixed blades 18 regularly distributed around the first axis X. These blades 18 are advantageously rotationally fixed about the first axis X. These blades 18 are located axially between the fan 2 and the low-pressure compressor 3. They are also known by the English acronym OGV for "Outlet Guided Varies". These blades 18 compress the secondary airflow F2 downstream of the fan 2 to improve the propulsive efficiency of the turbomachine 1.

[0067] These blades 18 advantageously have a variable pitch angle. The blades 18 are thus rotatable about a pitch axis Y extending radially with respect to the first axis X. This feature makes it possible to improve the propulsive efficiency of the turbomachine 1 depending on the operating conditions of the turbomachine 1.

[0068] To vary the pitch angle of the fixed blades 18, the turbomachine 1 includes a pitch changing system 19 connected to these blades 18.

[0069] The blades 18 are carried by the upstream casing 8, also called the “casing” in the context of the present invention.

[0070] The upstream casing 8 according to the invention will now be described in detail.

[0071] As more clearly seen in [Fig. 2], the upstream housing 8 comprises an annular body 8a centered on the first axis X. This body 8a preferably comprises a The first ferrule 20 and a second ferrule 21 are axially connected. The first ferrule 20, also called the upstream ferrule, is annular and centered on the first X-axis. The second ferrule 21, also called the downstream ferrule, is annular and centered on the first X-axis.

[0072] The first ferrule 20 is, for example, free to rotate about the first X. It extends longitudinally between an upstream annular end 22 and a downstream annular end 23. The upstream annular end 22 has an upstream annular flange 22a and the downstream annular end 23 has a downstream annular flange 23a. The upstream annular flange 22a is, for example, connected to an air inlet nozzle of the turbomachine 1.

[0073] The second ferrule 21 is, for example, fixed against rotation. It also extends longitudinally between an upstream annular end 24 and a downstream annular end 25. The upstream and downstream annular ends 24, 25 have respectively an upstream and downstream annular flange 24a, 25a.

[0074] The first and second ferrules 20, 21 are axially connected to each other. For example, the downstream flange 23a of the first ferrule 20 is connected to the upstream flange 24a of the second ferrule 21. Connecting rods, such as screws, can hold the downstream and upstream flanges 23a, 24 together. These connecting rods are evenly spaced around the first axis X.

[0075] Furthermore, according to the invention, the upstream casing 8 includes sleeves 26 for supporting the blades 18. Each blade 18 includes a foot 18a which is engaged in one of the sleeves 26. There are therefore as many sleeves 26 as there are blades 18. The sleeves 26 are regularly distributed around the first axis X.

[0076] Each sleeve 26 comprises an annular wall 27 and an internal housing 28 delimited by the annular wall 27 and receiving the foot 18a of a fixed blade 18. The annular wall 27 extends around a second axis Y extending radially with respect to the first axis X. The second axis Y thus corresponds to the alignment axis of the blades 18. The annular wall 27 has a circular cross-section with respect to the second axis Y.

[0077] According to the invention, each sleeve 26 is connected to the upstream housing body 8 by a first radial link L1 with respect to the first axis X and a second radial link L2 with respect to the first axis X.

[0078] By "radial connection" is meant a connection involving at least two bearing surfaces extending in a plane parallel to the first axis X and connected to each other. In particular, these bearing surfaces are connected by a set of means for securing the upstream housing body 8 to the sleeve 26 located in a plane perpendicular to the first axis X.

[0079] Preferably, each sleeve 26 is connected to the first ferrule 20 by the first link L1 and to the second ferrule 21 by the second link L2. According to this preferred embodiment of the invention, each sleeve 26 is therefore connected to both the first ferrule 20 and the second ferrule 21.

[0080] The first and second bonds L1, L2 are preferably diametrically opposed and located one behind the other along the first axis X.

[0081] Each sleeve 26 comprises a first connecting arm 29 and a second connecting arm 30. Each first and second connecting arm 29, 30 connects a sleeve 26 to the upstream housing body 8. In particular, each first connecting arm 29 connects the annular wall 27 of the sleeve 26 to the first ferrule 20 and each second connecting arm 30 connects the annular wall 27 of the sleeve 26 to the second ferrule 21.

[0082] Each first connecting arm 29 extends from the annular wall 27 of the sleeve 26 to the body of the upstream housing 8, in particular to the first ferrule 20. Each first connecting arm 29 extends, for example, radially or substantially radially towards the interior of the upstream housing 8. Each first connecting arm 29 comprises a first end fixed to the annular wall 27 of the sleeve 26 and a second end connected to the body of the upstream housing 8 by the first connection L1. Each first connecting arm 29 further comprises a tab 31 located on the second end of the first connecting arm 29. The tab 31 has an axial bearing surface 31a extending in a plane parallel to the first axis X. The axial bearing surface 31a of the tab 31 is oriented inwards. This axial bearing surface 31a cooperates radially with a corresponding axial bearing surface of the inlet housing body 8, in particular of the first ferrule 20.This corresponding axial bearing surface of the body is oriented outwards and extends in a plane parallel to the first X axis. These bearing surfaces 31a are radially connected to each other by screwing to form the first LL connection. The lug 31 has, for example, at least one orifice 31b which has an axis perpendicular to the first X axis. A screw (not shown) passes through the orifice to connect the first connecting arm 29 to the upstream housing body 8. The screw has an elongation axis perpendicular to the first X axis.

[0083] The second connecting arm 30 is radially opposed to the first connecting arm with respect to the second axis Y. The second connecting arm 30 extends from the annular wall 27 of the sleeve 26 to the upstream housing body 8, in particular to the second ferrule 21.

[0084] Each second connecting arm 30 comprises a first portion 32, a second portion 33, and an intermediate portion 34 connecting the first and second portions 32, 33. The first portion 32 extends substantially parallel to the first axis X from the annular wall 27.

[0085] The second portion 33 extends substantially radially to the first axis X and is connected to the body of the upstream housing 7, in particular to the second ferrule 21. The second portion 33 has an inwardly oriented tab 35 which has an axial bearing surface 35a extending in a plane parallel to the first axis X. The axial bearing surface 35a is oriented inwards. The axial bearing surface 35a cooperates radially with a corresponding axial bearing surface of the body of the inlet housing 8, in particular to the second ferrule 21. The corresponding axial bearing surface of the body is oriented outwards. These bearing surfaces 35a are radially connected to each other by screwing to form the second connection L2. The tab 35 has, for example, at least one opening, and advantageously two openings 35b, each of which has an axis perpendicular to the first axis X.A screw (not shown) passes through the opening to connect the second connecting arm 30 to the upstream housing body 8. The screw has an elongation axis perpendicular to the first axis X.

[0086] The intermediate portion 34 of the second arm 30 connects the first and second portions 32, 33. The intermediate portion 34 is curved. The intermediate portion 34 thus presents a concave internal surface 34a. This feature allows for radial space E between the second arm 30 and the upstream housing body 8. This space E can be used for the passage of utilities or other equipment. Furthermore, this curved shape concentrates stresses related, for example, to bird ingestion, within the intermediate portion 34. This curved shape also increases the flexibility of the sleeve 26 and thus limits deformations of the second ferrule 21. This helps to minimize clearances between the first and second ferrules 20, 21.

[0087] The second arm 30 may include a recess 30a. This recess 30a may be located at the first portion 32. It may have a generally triangular shape. Such a recess 30a makes it possible to reduce the total mass of each sleeve 26.

[0088] As more clearly seen in [Fig.3], the second bond L2 is located more radially closer to the first X axis than the first bond LL. Advantageously, the first bond L1 is located radially closer to the second Y axis than the second bond L2, the term "radially" being understood with respect to the second Y axis.

[0089] As shown in [Fig. 3], advantageously, each sleeve 26 comprises a dial 36 surrounding the annular wall 27. Each dial 36 has a shape, for example, polygonal, such as square or rectangular. The dial 36 of each sleeve 26 has openings 36a.

[0090] Each sleeve 26 may further include a tab 37 for example connected to the second connecting arm 30.

[0091] According to an advantageous embodiment of the invention, with reference to figures 4 to 10, the sleeves 26 are connected to each other by connecting plates 40.

[0092] Figures 4 and 5 show part of the housing 8 and part of the plates 40 which connect the sleeves 26 of the housing 8. Figures 6 to 8 show examples of connecting plates 40 and Figures 9 and 10 show two sleeves 26 connected to each other by a connecting plate 40.

[0093] The plates 40 are distributed around the first axis X and are each mounted between two adjacent sleeves 26.

[0094] Each of the plates 40 has a first circumferential end 40a fixed on a first of the two adjacent sleeves 26 and a second opposite circumferential end 40b fixed on a second of the two adjacent sleeves 26.

[0095] Each of the plates 40 preferably includes a rectangular or trapezoidal peripheral contour, as illustrated in figures 6 to 8. The circumferential ends 40a, 40b of the plates 40 are then formed by opposite sides of this contour.

[0096] The plates 40 are preferably fixed to the sleeves 26 by screws or bolts 41 (Figures 9 and 10). The circumferential ends 40a, 40b of the plates 40 may each include at least two holes 42 for the passage of the screws or bolts 41. These holes 42 are intended to be aligned with the holes 36a of the sleeves 26, and in particular of their frames 36. The screws or bolts 41 pass through the holes 36a and 42. The circumferential ends 40a, 40b of the plates may rest radially on circumferential ends of the frames 36 (Figures 9 and 10).

[0097] As can be seen in Figures 6 to 8, at least some of the plates 40 include a central hollowed-out portion. The hollows 44 in the plates 40 can have one or more functions, including a function of reducing the mass of the plates 40 and of the housing 8 as a whole.

[0098] The plates 40 are of at least two or three different types. The plates 40 of each type are identical to each other and different from the plates 40 of each other type.

[0099] Figures 6 to 8 show three different types of plates 40.

[0100] The plate 40 of [Fig.6] may differ from the other plates by its angular extent 0 around the first axis, and / or by the shape of its recess 42 for example.

[0101] The plate 40 of [Fig.7] may differ from the other plates in its general shape, and / or in its angular extent 0 around the first axis, and / or in the shape of its recess 42 for example.

[0102] The plate 40 of [Fig.8] may differ from the other plates by its angular extent 0 around the first axis, and / or by the shape of its recess 42 for example.

[0103] The differences between two types of plates 40 may result from differences in their functions. Plates 40 with a smaller angular range are, for example, intended to be mounted between sleeves that are separated from each other by a smaller circumferential distance. It follows, therefore, that plates 40 with a larger angular range are intended to be mounted between sleeves that are separated from each other by a greater circumferential distance. Indeed, the sleeves 26 may not all be separated from each other by the same circumferential distance around the first X-axis. In other words, the sleeves 26 are not necessarily evenly distributed around the first X-axis.

[0104] The plate 40 of [Fig.7] has a particular shape which can be explained by its function of supporting an actuator configured to control the angular positioning of the blades 18. The plate 40 of [Fig.7] thus includes a mounting housing 46 for this actuator 48 visible in [Fig.4].

[0105] The actuator 48 can extend parallel to the first X axis.

[0106] The housing 46 may include at least one annular flange 50 extending in a plane perpendicular to the first axis X and through which the actuator 48 passes. Figure 4 shows that the actuator 48 is of the cylinder type and comprises a cylinder 48a fixed to the flange 50, and a cylinder rod 48b passing through the flange 50 and extending over the entire length of the plate 40 along the first axis X. The end of the rod 48b opposite the cylinder is connected to a control ring 52 for actuating the angular positioning of the vanes 18. This control ring 52 may be connected by hinged levers to the aforementioned tabs 37.

[0107] In the embodiment shown in Figures 11 and 12, the housing 8 further includes covers 54 which extend around the first axis X and the annular body 8a.

[0108] Each of the hoods 54 has an opening 56 aligned radially with one of the sleeves 26 for the passage of the corresponding blade foot 18a.

[0109] The hoods 54 are fixed to the plates 40 by spacers 58 which extend radially between the hoods 54 and the plates 40.

[0110] Each of the spacers 58 can include a radially internal end 58a fixed to one of the plates 40, for example in its middle, and a radially external end 58b fixed to two adjacent hoods 54, and in particular to circumferential ends 54a, 54b opposite these two adjacent hoods 54.

[0111] The casing may further include servitudes 60 such as cables or conduits, these servitudes 60 extending parallel to the first axis X and being fixed to at least one of the plates 40 ([Fig. 11]).

[0112] The invention offers several advantages, including:

[0113] - the plates are optimized to have multiple functions. The concept can therefore to interest several systems that must reconcile classic problems in the Aircraft engines: small size, significant mass challenge, resistance to significant stresses, etc.

[0114] - the plates are capable of resisting the ingestion of foreign bodies such as a bird For example, while limiting the increase in mass of the crankcase, and while reducing the wear of clearances in the turbomachine, each plate effectively distributes part of the intake force towards the two adjacent plates.

[0115] - the casing and its sleeves are sufficiently rigid in the axial direction (motor shaft) to withstand the ingestion forces, which are predominant over aerodynamic forces; when the sleeves are subjected to aerodynamic forces (especially from the intrados to the extrados), the plates are likely to twist; The invention therefore makes it possible to limit the torsion of the sleeves, making the casing conform to the blade displacement specification.

[0116] - the plates can also allow for the attachment of the control actuator of the shimming, in the sense that they can notably allow the cylinder rod to be aligned with a control ring actuating link (thus limiting radial forces in the actuator, and therefore maximizing the actuator's ability to push in the axial direction); moreover, fixing the actuator to one of the plates allows it to move with the housing, also fixing the kinematics, and therefore limiting dispersions during operation,

[0117] - the plates can support vein caps;

[0118] - the optimization of the mass / stiffness of the plates, and in particular their central recesses, can be designed to facilitate access to adjustable connecting rods during engine operation.

[0119] - finally, the plates can allow the attachment of many elements that it would have been very expensive in terms of mass to connect to the crankcase, for example a system for redirecting an external cooling flow, piping and instrumentation, etc.

Claims

Demands

1. Casing (8) for a turbomachine (1), in particular for an aircraft, the casing (8) comprising: - at least one annular body extending about a first axis (X), - sleeves (26) adapted to receive blade roots (18a), the sleeves (26) being distributed about the first axis (X), each sleeve (26) having an annular wall (27) extending about a second axis (Y) oriented radially with respect to the first axis (X), each sleeve (26) being connected to the body by a first radial connection (L1) with respect to the first axis (X) and by a second radial connection (L2) with respect to the first axis (X), the first and second connections (L1, L2) being diametrically opposed and located one behind the other along the first axis (X), and - connecting plates (40) for the sleeves (26), the plates (40) being distributed around the first axis (X) and each being mounted between two adjacent sleeves (26),each of the plates (40) having a first circumferential end (40a) fixed to one of the two adjacent sleeves (26) and a second opposite circumferential end (40b) fixed to a second of the two adjacent sleeves (26).

2. Carter (8) according to claim 1, characterized in that each of the plates (40) comprises a rectangular or trapezoidal peripheral contour, said first and second circumferential ends (40a, 40b) being formed by opposite sides of this contour.

3. Housing (8) according to claim 1 or 2, characterized in that the plates (40) are fixed to the sleeves by screws or bolts (41).

4. Housing (8) according to the preceding claim, characterized in that said first and second circumferential ends (40a, 40b) each comprise at least two first orifices (42) for the passage of screws or bolts (41), these first orifices (42) being aligned with second orifices (36a) of the sleeves (26) suitable for receiving the screws or bolts (42).

5. Carter (8) according to any one of the preceding claims, characterized in that at least some of the plates (40) comprise a hollowed-out central portion.

6. Carter (8) according to any one of the preceding claims, characterized in that the plates (40) are at least of two or three different types, the plates (40) of each type being identical to each other and different from the plates (40) of each other type.

7. Carter (8) according to claim 6, characterized in that the plates (40) of a first of the types have an angular extent around the first axis (X) which is different from the plate (40) of each other type.

8. Housing (8) according to any one of the preceding claims, characterized in that it further comprises an actuator (48) configured to control the angular positioning of said blades (18), and in that at least one of the plates (40) comprises a housing (46) for mounting this actuator (48).

9. Housing (8) according to claim 8, characterized in that the actuator (48) extends parallel to the first axis (X).

10. Housing (8) according to claim 8 or 9, characterized in that the housing (48) comprises at least one annular flange (50) extending in a plane perpendicular to the first axis (X) and through which the actuator (48) passes.

11. Housing (8) according to any one of the preceding claims, characterized in that it further comprises hoods (54) which extend around the first axis (X) and the annular body (8a), each of the hoods (54) having an opening (56) aligned radially with one of the sleeves (26) for the passage of the corresponding blade foot (18a), the hoods (54) being fixed to the plates (40) by spacers (58) extending radially between the hoods (54) and the plates (40).

12. Carter (8) according to claim 11, characterized in that each of the spacers (58) comprises a radially internal end (58a) fixed to one of the plates (40), for example in its middle, and a radially external end (58b) fixed to two adjacent covers (54) of said covers, and in particular to circumferential ends (54a, 54b) opposite these two adjacent covers (54).

13. Carter (8) according to any one of the preceding claims, characterized in that it further comprises easements (60) such as cables or conduits, these easements extending parallel to the first axis (X) and being fixed to at least one of the plates (40).

14. Turbomachine (1), in particular aircraft, comprising a casing (8) according to any one of the preceding claims, and blades, in particular with variable pitch angle, the feet of which are engaged in the sleeves of the casing.

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