TURBOMACHINE ASSEMBLY EQUIPPED WITH VARIABLE STATOR BLADES AND A BEARING SUPPORT ASSEMBLY FOR THE BLADES

Abstract

The invention relates to a turbomachine assembly with a longitudinal axis X, particularly for aircraft, comprising a plurality of variable-pitch stator blades arranged around the longitudinal axis. According to the invention, the assembly includes a plurality of independent bearing housings, each intended to pivotally receive a stator blade root about a pitch axis, and an annular support member (35) centered on the longitudinal axis. The support member is equipped with a plurality of radially extending sleeves (36) provided with internal recesses (25) for removably receiving one of the bearing housings (26). The sleeves (36) are connected to each other, along the circumferential direction, by separate first fastening elements (50) and second fastening elements (51). (See Figure 6 for abbreviations.)

Description

Title of the invention: TURBOMACHINE ASSEMBLY EQUIPPED WITH VARIABLE-PITCH STATOR BLADES AND A SUPPORTING BODY FOR BEARING HOUSINGS OF THE BLADE Field of invention

[0001] The present invention relates to the field of turbomachines and in particular to a turbomachine assembly comprising variable-pitch blades which pivot by means of bearing housings and a support member for at least these housings. It also relates to the corresponding turbomachine. Technical background

[0002] Turbomachines comprising at least one unducted propeller are known by the English term "open rotor" or "unducted fan". In this category of turbomachine, there are those which have two unducted and counter-rotating propellers (known by the English acronym UDF for "Unducted Dual Fan") or those having a single unducted propeller and a rectifier comprising several stator blades (known by the English acronym USF for Unducted Single Fan). The propeller or propellers forming the propulsion part can be placed at the rear of the gas generator (or engine) so as to be of the pusher type or at the front of the gas generator so as to be of the tractor type. These turbomachines are turboprops which are distinguished from turbojets by the use of a propeller outside the nacelle (unducted) instead of an internal fan.This makes it possible to increase the dilution ratio significantly without being penalized by the mass of the casings or nacelles intended to surround the propeller or fan blades.

[0003] The stator vanes of the rectifier may be variable-pitch. In this case, the root of each stator vane is received in a housing of a ring so as to allow the vanes to rotate around their respective pitch axes.

[0004] However, when a foreign object of a certain weight, such as a bird of approximately 3 kg, impacts the stator blade, this causes stresses which reduce the mechanical strength of the ring. In particular, the impact would cause play in the moving blades of the low-pressure compressor which is located radially just below the ring and would damage the moving blades. Indeed, the support ring for the stator blades of the rectifier is connected to a turbomachine casing from which the stator blades extend, a deformation of this turbomachine casing may occur after impact which could damage the moving blades of the compressor. In addition, when maintaining the stator blades, an operator must access the fasteners on the turbomachine casing that carries the stator blades, which makes handling complicated. Summary of the invention

[0005] The objective of the present invention is to provide a solution making it possible to improve the mechanical strength of the stator blade support means and modularity in a simple and economical manner.

[0006] We achieve this objective in accordance with the invention by means of a turbomachine assembly with a longitudinal axis X, in particular an aircraft turbomachine assembly, comprising a plurality of variable-pitch stator blades which are arranged around the longitudinal axis, the assembly comprising a plurality of bearing housings which are independent and which are each intended to receive a stator blade root pivotably around a pitch axis, and an annular support member, centered on the longitudinal axis, the support member being equipped with a plurality of sleeves which extend radially and which are provided with internal housings each intended to receive in a removably manner one of the bearing housings, the sleeves being connected to each other, in the circumferential direction, by first fixing elements and by second fixing elements which are distinct.

[0007] Thus, this solution makes it possible to achieve the aforementioned objective. In particular, such a configuration of this support member with sleeves makes it possible, on the one hand, to lighten the mass of the assembly and of the turbomachine which comprises it, and on the other hand, to guarantee the mechanical strength of the bearing housings in the sleeves in the event of ingestion or impact of a foreign object on such stator blades. The annular structure of the support member with the sleeves connected together naturally reinforces its rigidity. The second fixing elements are configured to facilitate the passage of forces. The removable and independent mounting of each bearing housing in a sleeve makes it easier to manufacture the bearing housings as well as their geometric shape. The implementation of the bearing housings in the sleeves is also facilitated.Furthermore, the arrangement of such bearing housings allows intervention only on the stator blade which is damaged in the event of an impact, which reduces the environmental impact.

[0008] The assembly also includes one or more of the following features, taken alone or in combination:

[0009] - the first elements comprise solid wall portions.

[0010] - the support member comprises a support skeleton configured to carry an airflow vein panel.

[0011] - the support skeleton comprises a first hoop of substantially the shape annular and centered on the longitudinal axis, and a plurality of beams which are arranged around the longitudinal axis, the beams each being on the one hand secured to a first fixing element and on the other hand fixed to the first hoop.

[0012] - the support skeleton comprises a second ring centered on the longitudinal axis and a plurality of arms which are arranged around the longitudinal axis and which connect the first hoop to the second hoop.

[0013] - the first fixing elements and the second fixing elements are arranged radially apart.

[0014] - each sleeve extends radially between a first end and a second end, and the first fastening elements are disposed at the first end of the sleeves and the second fastening elements are disposed at the second end of the sleeves.

[0015] - the second elements each have a parallelepiped-shaped wall and two cross-shaped ribs connecting each corner of the wall, through openings being formed by the cross pattern of the two ribs.

[0016] - the second elements have a U-shaped radial section with a first branch and a second branch which are each connected to a sleeve.

[0017] - the second elements have an H-shaped cross-section with bases each connected to at least one sleeve.

[0018] - - the control means comprises a fixed body and an axially movable body by relation to the fixed body.

[0019] The invention also relates to an aircraft turbomachine comprising at least one assembly as mentioned above and a gas generator intended to drive an unducted propeller in rotation, the support member being fixed upstream to an inlet casing and downstream to a turbomachine casing.

[0020] According to a characteristic of the turbomachine, the inlet casing carries a separation nozzle intended to separate the air flow entering the turbomachine into a primary flow and the secondary flow, the stator blades extending radially in a secondary air flow and being unducted. Brief description of the figures

[0021] 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:

[0022] [Fig-1] [Fig.l] is a schematic view, in axial and partial section of an example of a turbomachine with a single unducted propeller to which the invention applies;

[0023] [Fig.2] [Fig.2] is a perspective view of an exemplary bearing housing for a variable-pitch stator blade according to the invention;

[0024] [Fig.3] [Fig.3] is a perspective view of an example of a support member for variable pitch stator blades according to the invention;

[0025] [Fig.4] [Fig.4] is a perspective and partial view of a set of tur- machine comprising the support member according to [Fig.3];

[0026] [Fig.5] [Fig.5] is a perspective and partial view of a turbomachine assembly comprising a support member with stator blade bearing housings which are housed in housings according to the invention;

[0027] [Fig.6] [Fig.6] is a perspective and partial view of an example of a support member equipped with a support skeleton for a vein wall of a turbomachine according to the invention;

[0028] [Fig.7] [Fig.7] is a perspective and partial view of another example of a sheave lization of a part of the support member according to the invention;

[0029] [Fig.8] [Fig.8] represents an embodiment of connection elements between sleeves of an example of a support member according to the invention;

[0030] [Fig.9] [Fig.9] shows another embodiment of connection elements between sleeves of an example of a support member according to the invention;

[0031] [Fig. 10] [Fig. 10] shows an embodiment of connection elements between sleeves of an example of a support member according to the invention; and

[0032] [Fig. 11] [Fig. 11] is a front view of a support member with a passage zone of a pylon of the turbomachine according to the invention. Detailed description of the invention

[0033] [Fig.l] represents a turbomachine 1 comprising an unducted propeller 2 intended to be mounted on an aircraft. Only the upstream part of the turbomachine is represented. Such a turbomachine is a turboprop which is known by the English expression “open rotor” or “unducted fan” as explained previously.

[0034] In the present invention, and generally, the terms "upstream", "downstream", "axial" and "axially" are defined with respect to the circulation of gases in the turbomachine and here along the longitudinal axis X (and even from left to right in [Fig. 1]). Similarly, the terms "radial", "internal" and "external" are defined with respect to a radial axis Z perpendicular to the longitudinal axis X and with respect to the distance from the longitudinal axis X. Furthermore, elements that are identical or substantially identical and / or with the same functions are represented by the same numerical references.

[0035] The turbomachine 1 comprises a gas generator or engine 3 which comprises ty upstream to downstream connection, a low pressure compressor 4, a high pressure compressor (not shown), a combustion chamber (not shown), a high pressure turbine (not shown) and a low pressure turbine (low pressure). The rotors of the low pressure compressor 4 and the low pressure turbine are mechanically connected by a low pressure shaft so as to form a low pressure body. The rotors of the high pressure compressor and the high pressure turbine are mechanically connected by a high pressure shaft so as to form a high pressure body.

[0036] In another configuration not shown, the low pressure or low pressure body comprises the low pressure compressor which is connected to an intermediate pressure turbine. A free power turbine is mounted downstream of the intermediate pressure turbine and is connected to the propeller described below via a power transmission shaft to drive it in rotation.

[0037] The propeller 2 of the turbomachine comprises several unducted moving blades 10 which extend radially from a rotating casing 11 and around the longitudinal axis X. In the example shown in [Fig.l], the propeller 2 is mounted upstream of the gas generator 3 (tractor configuration or "puller" in English). The moving blades 10 may have variable pitch.

[0038] As can also be seen in [Fig.l], the turbomachine 1 comprises a rectifier 20 comprising a plurality of stator vanes 21 (or fixed vanes) known by the English acronym “OGV” for Outlet Guide Vane. The stator vanes 21 are distributed regularly around the longitudinal axis X and extend radially in a secondary air flow F2. The latter comes from an air flow F passing through the propeller 2 upstream and separated by a separation nozzle 5. The stator vanes 21 of the rectifier 20 make it possible to straighten the air flow generated by the propeller 2. The stator vanes 21 of the rectifier 20 are also unducted. The turbomachine shown is a USF, there is no fairing of the propeller 2 or the rectifier 20. A primary air flow Fl also coming from the air flow F after separation circulates through the gas generator 3.

[0039] Each stator blade 21 comprises a root 22 and a blade 23 which extends radially from the root 23. Each blade 23 comprises an opposing leading edge 23a and trailing edge 23b which are connected by an intrados surface 23i and an extrados surface (not shown).

[0040] Advantageously, the stator blades 21 are variable-pitch. To this end, the turbomachine 1 advantageously, but not limited to, comprises a pitch-changing system 24 (shown in [Fig. 1]) which is configured to change the pitch of the blades 2 depending on the operating mode of the turbomachine. The root 22 of each blade 21 is typically in the form of a pivot which is pivotally mounted along a pitch axis A in an internal housing 25. Each root 22 is pivotally mounted by means of at least one bearing housing 26 described below.

[0041] [Fig. 2] illustrates an example of a bearing housing 26 which is intended to ensure the retention and rotation of a blade root 22 in its corresponding internal housing 25. The bearing housing 26 comprises a cylindrical wall 27 with an axis of revolution B. The latter is coaxial with the setting axis A in the installation situation. The bearing housing 26 comprises an inner ring (not shown) and an outer ring (not shown) which are centered on the axis of revolution B. Each inner ring is integral in rotation with a root 22. The outer ring surrounds the inner ring and is secured to the cylindrical wall 27. Rolling members (not shown) are installed between the internal surfaces of the inner and outer rings which form rolling tracks. The rolling members here comprise balls.

[0042] Optionally, two inner and outer rings are superimposed along the radial axis B. In order to facilitate their holding in position and mounting in the bearing housing 26, the latter comprises an annular bulge 28 which is centered on the axis of revolution B and which extends from an internal surface 29 of the cylindrical wall 27. The outer rings bear radially on the annular bulge 28. The bulge 28 makes it possible to transmit the forces. Advantageously, this configuration allows an X-shaped mounting known to those skilled in the art. Furthermore, the bulge 28 makes it possible to ensure a radial spacing between the outer rings and the absorption of the bending moment.

[0043] Advantageously, the bearing housing 26 comprises a sole 30 which extends radially from the cylindrical wall 27. The sole 30 has an upper surface 30a and a lower surface 30b which are each defined in a plane perpendicular to the axis of revolution B.

[0044] With reference to Figures 3 and 4, the turbomachine 1 comprises a support member 35 which is equipped with a plurality of sleeves 36 which are arranged around the longitudinal axis X. Each sleeve 36 comprises an internal housing 25 intended to removably receive the bearing housing 26. In particular, each sleeve 36 comprises a cylindrical skirt 37 with an axis of revolution C parallel to the radial axis Z. The cylindrical skirt 37 delimits the internal housing 25. The latter passes through the wall of the cylindrical skirt 37 on either side radially. Each sleeve 36 extends radially between a first end 37a and a second end 37b. A first opening 38 and a second opening 39 are arranged respectively at the first end 37a and the second end 37b. The internal housing 25 passes radially through the cylindrical skirt 37 and opens into both the first opening 38 and the second opening 39.

[0045] Optionally, each sleeve 36 comprises a collar 40 which extends radially from the cylindrical skirt 37 (and preferably towards the first end 37a). The collar 40 here surrounds the first opening 38. Advantageously, the collar 40 has an external surface 40a, advantageously flat. The sole 30 of each bearing housing 26 is intended to be fixed on the external surface 40a of the sleeves 36. Advantageously, the lower surface 30b rests in flat support on the external surface 40a. The collar 40 and the sole 30 respectively comprise through holes 41 allowing them to be fixed using fixing members (not shown) such as bolts. This allows the individual removal of each stator blade 21 if it is damaged.

[0046] [Fig. 5] illustrates examples of blade roots 22 which are housed respectively in a bearing housing 26. Each root 22 typically comprises a barrel 42 which is intended to extend inside the bearing housing 26. The or each internal ring is secured to the barrel of the root 22. Advantageously, each root 22 comprises a plate 43 which extends radially at one of the ends of the root 22. Each plate 43 is intended to be fixed to a platform (not shown) which is located at one end of the root of the blade 23. The fixing can be carried out by bolt-type fixing members or other suitable means at the platform. Each plate 43 and each platform comprise for this purpose orifices 44 cooperating with the fixing members.

[0047] As also illustrated in [Fig. 5], each plate 43 of a foot 22 is advantageously connected to a connecting mechanism 45 of the pitch change system 24. The connecting mechanism 45 comprises at least one lug 46 which extends transversely from each plate 43. Each lug 46 comprises at its opposite end an ear 47 secured to a tilting finger 48. In other words, there are several tilting fingers 48, and as many as stator blades 21, which are arranged regularly around the longitudinal axis X. Each tilting finger 48 extends radially. Advantageously, the tilting fingers 48 are connected two by two using connecting rods 49. These connecting rods 49 are each articulated relative to the tilting fingers 48. This makes it possible to transmit the rotational movement of a blade 21 to at least one other adjacent blade 21 in the circumferential direction.

[0048] Advantageously, but not limitatively, the pitch change system 24 further comprises at least one control means (not shown) acting on the connecting mechanism 45 so as to control its rotation around its setting axis A. The control means being connected to the root 22 of at least one of the variable-pitch blades. In the present example, the connecting mechanism 45 makes it possible to connect the or each control means to at least one root 22.

[0049] Advantageously, but not limitatively, the control means comprises a fixed body connected to a stator of the turbomachine and a movable body, relative to the body fixed, which is connected to at least one of the tilting fingers 48. The control means is optionally an actuator which is connected to a fluid supply source to supply pressurized oil to chambers (not shown) of the fixed body whose volume changes depending on the movement of the mobile body.

[0050] Advantageously, the sleeves 36 are connected to each other in the circumferential direction by first fixing elements 50 and by second fixing elements 51. The first elements 50 are distinct from the second elements 51. Optionally, the first elements 50 are arranged at a radial distance from the second elements 51. The first elements 50 are for example arranged at the first end 37a of the sleeves and the second elements 51 are for example arranged at the second end 37b of the sleeves 36. At least the second fixing elements are configured to facilitate the passage of forces.

[0051] According to an exemplary embodiment, the sleeves 36, the first elements 50 and the second elements 51 are formed from a single piece (made from one piece). In this way, the support member 35, centered on the longitudinal axis X, can be arranged easily and more quickly in the turbomachine. These can be manufactured by a foundry technique, lost wax casting or by additive manufacturing.

[0052] With reference to [Fig. 6], the first elements 50 comprise, for example, solid wall portions 52. The wall portions 52 extend circumferentially between each pair of sleeves 36. Advantageously, each wall portion 52 has an external surface 52a which has surface continuity with the external surface 40a of each collar 40. Optionally, the external diameter measured at the wall portions 52 is identical to the external diameter measured at the collars 40.

[0053] In [Fig. 6], the support member 35 comprises a support skeleton 53 configured to carry at least one airflow vein panel 54 (which is visible transparently in [Fig. 6]). In the case of this example, the vein panel 54 makes it possible to guide the secondary airflow. The vein panel 54 is annular and can be sectorized in a circumferential direction (around the longitudinal axis). Alternatively, the vein panel 54 is formed in a single piece.

[0054] Advantageously, the skeleton 53 comprises several beams 55 which are arranged around the longitudinal axis X. The skeleton 53 comprises a first hoop 56 which is substantially annular and centered on the longitudinal axis X. Advantageously, each beam 55 is integral with the first elements 50 and is fixed to the first hoop 56. In particular, each beam 55 comprises a first end 57a which is fixed to a wall portion 52 and a second end 57b which is fixed to a first lateral flank 56a of the first hoop 56.

[0055] Advantageously, the beams 55 each extend substantially along the axis Ion- longitudinal X. Each beam 55 has an inclination which can be between 5 and 15° relative to the longitudinal axis X. In addition, each beam 55 has an external surface 55a which is flush with an external edge 56b of the first arch 56. Here, the external edge 56b connects the two lateral flanks 56a, 56c and an internal edge 56d. As can be seen in the figures, the diameter of the first arch 56 is greater than the diameter of the plurality of sleeves 36.

[0056] Each beam 55 has a main body 55a which extends between the first end 55a and the second end 55b. A base 58 arranged at the first end extends axially (in particular upstream). Advantageously, each beam 55 comprises a portion 55b which extends substantially radially (+ / -5°) between the base 58 and the main body 55aa. This portion 55b allows the change in diameter between the base 58 and the first hoop 56. A wing 59, arranged at the second end, extends radially (and in particular towards the longitudinal axis X).

[0057] Advantageously, the beams 55 are formed in a single piece with the wall portions 52. On the other hand, the flange 59 of each beam 55 is fixed using fixing members (such as bolts) to the first hoop 56.

[0058] The first hoop 56 can be made of metallic material (for example titanium) or of composite material.

[0059] [Fig.7] illustrates another embodiment of the beams 55. Each beam 55 has an axial section in the general shape of a diamond. In this case, each base 58 forms a first branch 60a of the diamond and extends over the entire axial length of a portion of wall 52. A second branch 60b extends transversely between the base 58 and the main body 55aa forming a third branch 60c of the diamond. Each beam 55 comprises a transverse bar 60d which extends radially at the junction between the base 58 and the second branch 60b and the junction between the main body 55aa and the portion 55b. Each beam 55 comprises the flange 59 which allows it to be fixed to the first hoop 56. The fourth branch 60d here is formed by the portion 55b of the beam 55.

[0060] The shape of the beam 55, in the embodiments illustrated in Figures 6 and 7 in particular, depends on the ratio between stiffness and mass.

[0061] According to Figures 3 to 7, the support skeleton 53 comprises a second annular hoop 61 and is centered on the longitudinal axis X. The skeleton 53 further comprises a plurality of arms 62 which are arranged around the longitudinal axis X. Advantageously, the arms 62 connect the first hoop 56 to the second ring 61. The arms 62 are for example distinct from the beams 55. In the present example, each arm 62 comprises for example a spar 63 which extends substantially (+ / - 5°) along the longitudinal axis X.

[0062] The second hoop 61 can be made of metallic material (for example in titanium) or composite material.

[0063] Advantageously, each spar 63 is arranged in the continuity of the main body 55aa of each beam 55. Each spar 63 has an external surface 63a flush with the external edge 56b of the first arch 56. Each spar 63 comprises a wing 64 which extends radially and which is fixed to the lateral flank 56c of the first arch 56 using fixing members such as bolts. In this way, the vein panel 54 can rest at least on the beams 55. The vein panel 54 is advantageously fixed at least on the beams 55 using fixing members. In the case of a sectorized vein panel 54, each panel sector is independent so as to facilitate its assembly and disassembly. The vein panel 54 can also rest both on the beams 55 and on the spar 63.

[0064] According to an embodiment not shown, the vein panel 54 comprises an upstream panel (in one piece or sectored) which rests and is fixed on the beams 55. The vein panel 54 also comprises a downstream panel (in one piece or sectored) which rests and is fixed on the side members 63. In this case, the upstream panel has a length substantially equal (+ / - 5% for example) to the length of the beams 55 and the downstream panel has a length substantially equal (+ / - 5% for example) or greater than that of the side members 63. The fixing members of these panels comprise for example screws and are accessible from the external surface of the panels. The upstream and downstream panels are independent of each other so as to mount or dismount them independently of each other. Alternatively, the downstream panel can be mounted so as to be able to move relative to the side members 63. The upstream and downstream panels can have the same thickness.Advantageously, the external surfaces of the upstream and downstream panels are flush.

[0065] According to another advantageous characteristic, each arm 62 comprises a base 66 which extends transversely between each spar 63 and the second hoop 56. In the present example, each base 66 has a Y-shaped axial section with the two branches 66a, 66b which are connected to the spar 63 and the leg 66c of the base 66 connected to the second hoop 61. Each base 66 can be formed in a single piece with the spar 63. The leg 66c of the base 66 is, on the other hand, fixed to the second hoop 61 by means of fixing members such as bolts.

[0066] The second hoop 61 has a diameter which is smaller than that of the first hoop 56. This makes it easier to arrange the support member in this dedicated space.

[0067] Figures 8 to 10 illustrate different embodiments of the second fixing elements 51 which in particular have a structural role. The second fixing elements make it possible to connect the sleeves 26 at their second ex- junctions.

[0068] With reference to [Fig. 8], the second fastening elements 51 each have an openwork wall 70. In particular, each wall 70 has a parallelepiped shape. The second element 51 extends in the circumferential direction and also along the longitudinal axis. Its thickness along the radial axis is constant here. In this embodiment, the second element 51 comprises two cross-shaped ribs 71a, 71b which connect each corner of the wall 70. The center of the cross is at the center of the wall 70. Four openings 72 are formed here by the cross pattern. Of course, the arrangement of the ribs 71a, 71b may be different as well as the number of openings. Advantageously, the second fastening elements 51 are formed in one piece with the sleeves 36 (preferably by casting, by additive manufacturing or other).The second elements and the sleeves can be considered as an additional casing with a weight saving. Alternatively, the second elements 51 are added and fixed between the sleeves, for example by welding.

[0069] The second elements 51 of the embodiment of [Fig.9] have a U-shaped radial section. In particular, each second element 51 comprises a first branch 73a and a second branch 73b which extend radially and which are connected to the sleeves 36. A bottom 74 makes it possible to connect the first and second branches 73a, 73b. Each bottom 74 faces a first fixing element 50. In the present example, the bottom 74 has an opening 85 which is optional and which makes it possible to lighten each second element 51. Each sleeve 36 optionally comprises two projections 75 which extend on either side of the peripheral skirt 37 thereof and in the circumferential direction. The projections 75 are formed here at each second end 37b. Each first branch 73a and second branch 73b of a second element 51 is removably attached to a projection 75.Advantageously, each projection 75 has a radial face defined in a radial plane and which is intended to rest against a lateral surface 73aa, 73ba of a first or second branch 73a, 73b. The wall of the first and second branches 73a, 73b as well as that of the projections 75 are provided with orifices 76 which are intended to cooperate with fixing members such as bolts. Advantageously, but not limitingly, each projection 75 comprises keyed sockets.

[0070] The second elements 51 of [Fig. 10] each have a general axial section in the shape of an H. Advantageously, each second element 51 comprises a rod 77 and two bases 78a, 78b which extend transversely respectively at one end of the rod. In the installation situation, each rod 77 extends along the longitudinal axis. Each first and second base 78a, 78b extends radially. Each first and second base 78a, 78b can be connected to a wall portion 52 of the first fixing elements 50. In other words, the height of the first and second bases is equal to the distance separating the first and second fixing elements. This provides additional rigidity. Alternatively, each first and second base 78a, 78b has a height less than the distance between the first and second fixing elements.

[0071] Each first and second base 78a, 78b comprises two rims 79a, 79b which are opposite in the circumferential direction (in the installation situation). Each rim 79a, 79b is secured to a projection 75 of an adjacent sleeve 36. Advantageously, but not limitingly, the second elements 51 of this [Fig. 10] are formed in one piece with the sleeves 36 (preferably by casting, by additive manufacturing or other). Alternatively, the second elements 51 are added and fixed between the sleeves for example by welding.

[0072] As can be seen in the various figures, the support member 35 is fixed to an inlet casing of the turbomachine. The sleeves 36 comprise bridges 80 which are each intended to be fixed to an inlet casing 81 located upstream (and illustrated in [Fig.l]). The inlet casing 81 is centered on the longitudinal axis X. The inlet casing 81 typically extends radially outside an internal casing 82 which at least partially envelops the gas generator 3. In the present example, the inlet casing 81 carries the separation nozzle 5 which separates the primary flow from the secondary flow. The bridges 80 each extend from the peripheral skirt 37 along the longitudinal axis X and upstream. Each bridge 80 comprises at least one orifice 81 allowing it to be fixed to a flange (not shown) of the inlet casing of the turbomachine. Fastening devices such as bolts to achieve this fixing.The orifices 83 advantageously pass through the wall of each bridge 81.

[0073] The support member 35 is advantageously fixed to a turbomachine casing 90 which is located downstream and which carries the rectifier 20. The turbomachine casing 90 is downstream of the inlet casing 81. In particular, the second hoop 61 allows the support member 35 to be fixed to the turbomachine casing 90. The second hoop 61 therefore comprises several orifices 84 which pass through its wall on either side and which are regularly distributed around the longitudinal axis X. Fixing members allow the fixing to be finalized.

[0074] Advantageously, the pitch change system 24 is arranged in an annular space defined between the inlet casing 81 and the turbomachine casing 90. The configuration of the support member 35 with numerous spaces between the skeleton 53 and the sleeves 36 facilitates the insertion of the pitch change system 24 and the services for the supply of fluid for the pitch change system.

[0075] With reference to [Fig. 11] and [Fig. 3], the support member 35 comprises an area 86 configured for installation and passage thereof under a pylon (not shown). Advantageously, the pylon, which allows the turbomachine to be suspended from the aircraft, is located at least partly between two stator vanes of the rectifier and extends axially downstream. The zone 86 is preferably located at noon with reference to the dial of a clock. The zone 86 is advantageously formed by a first wall 87 and a second wall 88 which are connected to each other substantially forming a V. The tip of the V is oriented towards the longitudinal axis X. The first and second walls 87, 88 are each connected at their ends opposite the tip of the V to the remainder of the first arch 56. The first and second walls 87 and 88 are each inclined relative to the longitudinal axis X at an angle of approximately 45°. In this zone 86, two wall portions 52' are also inclined relative to the longitudinal axis X and are connected to a crosspiece 89.The latter extends along the longitudinal axis X and is also connected to the first and second walls at the tip of the V. Advantageously, the crosspiece 89 connects wall portions 52' to the second hoop 61. In this way, the pylon of the turbomachine can pass through this reinforcement zone for its installation. The zone 86 has a diameter DI which is the minimum compared to the support member 35. The diameter DI is measured at the level of the crosspiece 89 which is tangent to a circle centered on the longitudinal axis X. The diameter D2 of the remainder of the first hoop 56 is greater than the diameter DI.

[0076] In this way, the support member 35 makes it possible to facilitate the manufacture and implementation of each of the elements which compose it and which cooperate with it. The support member 35 has a function of supporting and stiffening the bearing housings and optionally a function of supporting the vein panel 54 with the skeleton 53. The various connections of the support member 35 made with fixing members make it possible to integrate composite materials which can lighten the structure.

Claims

Claims

1. A turbomachine assembly with a longitudinal axis X, in particular for an aircraft, comprising a plurality of variable-pitch stator blades (21) which are arranged around the longitudinal axis (X), characterized in that the assembly comprises a plurality of bearing housings (26) which are independent and which are each intended to receive a stator blade root (22) (21) pivotably around a pitch axis (A), and an annular support member (35), centered on the longitudinal axis (X), the support member (35) being equipped with a plurality of sleeves (36) which extend radially and which are provided with internal housings (25) each intended to receive in a removable manner one of the bearing housings (26), the sleeves (36) being connected to each other, in the circumferential direction, by first fixing elements (50) and by second fixing elements (51). which are distinct.

2. Assembly according to the preceding claim, characterized in that the first elements (50) comprise solid wall portions (52).

3. Assembly according to one of the preceding claims, characterized in that the support member (35) comprises a support skeleton (53) configured so as to carry an air flow vein panel (54).

4. Assembly according to the preceding claim, characterized in that the support skeleton (53) comprises a first hoop (56) of substantially annular shape and centered on the longitudinal axis (X), and a plurality of beams (55) which are arranged around the longitudinal axis (X), the beams (55) each being on the one hand integral with a first fixing element (50) and on the other hand fixed to the first hoop (56).

5. Assembly according to the preceding claim, characterized in that the support skeleton (53) comprises a second ring (61) centered on the longitudinal axis (X) and a plurality of arms (62) which are arranged around the longitudinal axis (X) and which connect the first hoop (56) to the second hoop (61).

6. Assembly according to any one of the preceding claims, characterized in that the first fixing elements (50) and the second fixing elements (51) are arranged at a radial distance.

7. An assembly according to any one of the preceding claims, characterized in that each sleeve (36) extends radially between a first end (37a) and a second end (37b) and in that the first fixing elements (50) are arranged at the first end (37a) of the sleeves and the second fixing elements (51) are arranged at the second end of the sleeves (36).

8. Assembly according to one of the preceding claims, characterized in that the second elements (51) each have a wall (70) of parallelepiped shape and two ribs (71a, 71b) in the shape of a cross connecting each corner of the wall (70), through openings (72) being formed by the cross pattern of the two ribs (71a, 71b).

9. Assembly according to one of claims 1 to 7, characterized in that the second elements (51) have a U-shaped radial section with a first branch (73a) and a second branch (73b) which are each connected to a sleeve (36).

10. Assembly according to one of claims 1 to 7, characterized in that the second elements (51) have an H-shaped cross section with bases (78a, 78b) each connected to at least one sleeve (36).

11. Assembly according to any one of the preceding claims, characterized in that the support member (35) comprises a zone (86) configured for the installation and passage of a pylon of the turbomachine, the zone (86) having a minimum diameter of the support member (35).

12. Assembly according to any one of the preceding claims, characterized in that it comprises a pitch change system (24) for the stator blades (21) comprising a connecting mechanism (45) connected to at least one blade (21) and a control means acting on the connecting mechanism (45) so as to control its rotation around its setting axis A.

13. Aircraft turbomachine comprising at least one assembly according to any one of the preceding claims and a gas generator (3) intended to drive an unducted propeller (2) in rotation, the support member (35) being fixed upstream to an inlet casing (81) and downstream to a turbomachine casing (90).

14. Turbomachine according to the preceding claim, characterized in that the inlet casing (81) carries a separation nozzle (5) intended to separate the air flow (F) entering the turbomachine into a primary flow (F1) and the secondary flow (F2), the stator vanes (21) extending radially in a secondary air flow (F2) and being unducted.

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