CONNECTION BETWEEN A WATERBORN FOOT AND A BRACING DEVICE

Abstract

CONNECTION BETWEEN A BLADE FOOT AND A SHINING DEVICE One aspect of the invention relates to an assembly (200) comprising: a blade (30) having a foot (31), a static blade support (40), a shimming device (210) connected to the blade support (40) characterized in that it comprises: a plate (13), a fixed jaw (11) having a first bearing surface (12), the fixed jaw (11) being integral with the plate (13), a movable jaw (21) having a second bearing surface (22), the fixed jaw (11) being connected to the movable jaw (21) by a fastening means, the foot (31) being in surface contact with: the first bearing surface (12), the second bearing surface (22) and a contact surface (14) of the plate (13). Figure to be published with the abbreviation: Figure 6

Description

Title of the invention: CONNECTION BETWEEN A BLADE FOOT AND A WEDGING DEVICE TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of turbomachines, in particular of a connection between a blade root and a blade support, in particular for a blade root of a stator blade. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] An example of a turbomachine comprising a connection between a blade root and a blade support is illustrated in [Fig.l], the invention being able to apply to such an example of a turbomachine. This illustrates an engine 500 with an unducted propeller of axis A. Upstream and downstream are understood here in relation to a general direction of an air flow along the axis A of the engine 500. Said engine 500 comprises a power generator compartment 51. The power generator compartment 51 drives an unducted propeller 59 comprising a plurality of rotor blades 521. An annular row 53 of stator blades 30 is fixed to a casing of the power generator compartment 51. This annular row 53 of blades 30 has the function of straightening an air flow driven by the propeller 59 from upstream to downstream and which passes around a static blade support 40. The annular row 53 comprises a plurality of blades 30 distributed circumferentially around the static blade support 40.The blades 30 are connected to the static blade support 40 using a wedging device 210.

[0003] Patent application FR 2996584 illustrates an example of a blade wedge, shown [Fig.2], according to the prior art. [Fig.2] shows a blade 48 (or vane) with variable pitch as well as a wedge 52 (or pivot) associated with the blade 48. The blade 48 comprises an aerodynamic part 60 as well as a root 58 in the form of a dovetail. The wedge 52 has a lower part 52a comprising ball bearings and placed inside an associated housing allowing rotation of the pivot, this lower part 52a being substantially cylindrical. The wedge 52 also has an upper part 52b comprising a groove 56, and the function of which is to retain the root 58 of the associated blade 48. The wedge 52 is connected to a blade support (called a ring in the application and not shown in the figure). The blade support is rotated by a turbomachine.

[0004] The problem with the connection between the blade 48 and the wedging device 52 is that it is suitable for blades undergoing a centrifugal force such that the blade tends to escape in a radial direction relative to the axis of rotation of the blade support. This connection is not effective for blades undergoing little or no centrifugal forces. trifuges. In addition, this connection is quite cumbersome compared to the very limited space in which the blade must fit.

[0005] Patent application FR 3087830 illustrates another example of a blade setting system, shown [Fig. 3], according to the prior art. In this example a root 420 of a blade 410 (or blade) is attached to a fastener 430 mounted in rotation relative to a hub allowing the blade 410 to pivot relative to the hub. In order to mount the blade 410 to the fastener 430, a stop (called a shim in the application) can be inserted into the bottom 440 of the fastener 430. The hub is rotated by a turbomachine.

[0006] It is noted that the method of mounting the root 420 on the attachment 430 requires a stop in that a cavity exists between the bottom of the attachment 440 and the end of the root 420 of the blade 410 mounted in the attachment 430. This is because the blade 410 has a tendency to move in a radial direction relative to the axis of rotation of the hub due to the centrifugal forces experienced by the blade 410. This type of mounting is therefore not suitable for blades not subject to centrifugal forces. In addition, the connections of the cited applications are bulky compared to the constrained space in which the root of the blade must be integrated.

[0007] [Fig.4] shows another example of the state of the art of blade timing similar to [Fig. 3]. A foot 520 of a blade 510 is inserted into a cell 580 of a disc 540. A stop 530 is positioned at the bottom of the cell 580 and is in contact with the foot 520. The foot 520 is thus in contact with two bearing surfaces 560 of the cell 580 and is also in contact with a surface 570 of the stop 530. The stop 530 makes it possible to generate sufficient prestress in order to ensure contact between the foot 520 and the bearing surfaces 560, thus making it possible to limit the swiveling of the foot 520. In operation, under the effect of centrifugal forces, the foot 520 will fit onto the bearing surfaces 560. Summary of the invention

[0008] The invention provides a solution to the problems mentioned above, by making it possible to fix by a wedging device a blade not subjected to centrifugal forces. The invention also makes it possible to improve the assembly and disassembly of a blade on a wedging device not requiring intervention on other parts of a turbomachine, thus saving time on a blade maintenance operation.

[0009] A first aspect of the invention relates to an assembly comprising: • a blade with a foot, • a static blade support, • a wedging device linked to the blade support comprising • a turntable, • a fixed bit comprising a first bearing, the fixed bit is attached to the turntable, • a movable jaw comprising a second bearing, the fixed jaw is linked to the movable jaw by a fixing means, the foot is in surface contact with: • the first litter, • the second range and • a contact surface of the plate.

[0010] Thus, the connection between the wedging device and the blade is particularly suitable for a blade not subjected to centrifugal force because the blade is in contact with three surfaces. This solution therefore allows the root not to move in the absence of centrifugal forces because it will be held by three surfaces and in particular by the contact surface of the plate, which does not exist in the prior art, making it possible to fix the blade to the wedging device.

[0011] The root integration zone is a zone that is highly constrained by the presence of numerous pieces of equipment around them. The assembly makes it possible to have a connection between the wedging device and the blade that is as compact as possible in the absence of centrifugal forces. The invention makes it possible to dispense with a stop present between the wedging device and the blade root and therefore presents a less bulky solution compared to the prior art. Thus, the wedging device will adapt better to the geometry of the blade root. The invention is radially compact along the axis of rotation of the blade compared to a wedging device of the prior art where a force is generated under the blade root, for example by a stop.

[0012] Advantageously, the movable jaw is removable from the wedging device. Thus, it is simpler to mount or dismount the foot from the wedging device because the foot can exit in a direction other than along the length of the groove. Removing the movable jaw leaves more room for the foot to exit or enter the housing of the wedging device.

[0013] Advantageously, the fixed jaw and the movable jaw each comprise two holes, each hole of the fixed jaw is aligned with a hole of the movable jaw, the fixing means is composed of two screws, each screw passes through the hole of the fixed jaw and the hole of the corresponding movable jaw of the wedging device.

[0014] Advantageously, the timing device is connected to the blade support via a pivot connection. Thus, the timing device is a variable timing device making it possible to reduce or increase the flow passing between the blade.

[0015] Advantageously, the assembly comprises a plurality of blades, each of the blades being secured to the fixed support by a wedging device.

[0016] The invention also relates to a mounting method comprising: • a step in the assembly process comprising placing the blade root in contact with the fixed jaw, • a step in the assembly process comprising placing the movable jaw on the plate, • a step of the assembly process comprising a connection of the fixed jaw with the movable jaw by the fixing means, • a step of the assembly process comprising the linear movement of the movable jaw towards the fixed jaw by the fixing means, • a step of the assembly process comprising locking the connection between the fixed jaw and the movable jaw by the fixing means.

[0017] Thus, it will be easier to intervene on a blade without having to intervene on other parts of the turbomachine. This results in a saving of time and cost on a maintenance operation of the blade for example.

[0018] Advantageously, according to a first variant of the assembly method, the method comprises between the step of linear displacement of the movable jaw and the step of locking the connection: • a sub-step of bringing the foot into contact with the plate following the linear movement of the movable jaw during the step of linear movement of the movable jaw.

[0019] Advantageously, according to a second variant of the assembly method, the method comprises before the step of placing the foot in contact with the fixed jaw: • a sub-step of placing the foot in contact with the plate.

[0020] The invention also relates to a method of dismantling the assembly comprising: • a first step of the dismantling process including unlocking the connection between the fixed jaw and the movable jaw, • a second stage of the disassembly process including the removal of the movable jaw • a third stage of the disassembly process comprising the removal of the blade.

[0021] The invention also relates to a turbomachine comprising an assembly with at least one of the preceding characteristics.

[0022] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0023] The figures are presented for information purposes only and in no way limit the invention.

[0024] [Fig. 1] is a perspective view of an unducted propeller engine.

[0025] [Fig.2] is a perspective view of a blade and a blade setting device according to the prior art.

[0026] [Fig.3] is a sectional view of a blade mounted in a fastener according to the prior art.

[0027] [Fig.4] is a front view of a blade mounted in a disc cell according to the art anterior and presenting a stop.

[0028] [Fig.5] is a sectional view of a blade of an assembly according to the invention comprising a wedging device for a blade root according to an exemplary embodiment.

[0029] [Fig.6] is a sectional view of [Fig.5] along section plane IV-IV of the assembly according to the same example of realization.

[0030] [Fig.7] is a sectional view of [Fig.6] along the section plane VV, along the same example of realization.

[0031] [Fig.8]] is a top view of a part of a fixed jaw and a plate according to the invention and according to the same exemplary embodiment.

[0032] [Fig.9] is a sectional view of [Fig.8] along section plane VII-VII of the bit fixed and a plate and according to the same example of realization.

[0033] [Fig. 10] is a sectional view of [Fig.9] along section plane VIII-VIII of the fixed jaw and a plate according to the same embodiment.

[0034] [Fig. 11] is a view of a method of mounting according to the invention of the assembly according to a first variant embodiment.

[0035] [Fig. 12] is a view of a method of mounting according to the invention of the assembly according to a second variant embodiment. DETAILED DESCRIPTION

[0036] Unless otherwise specified, the same element appearing in different figures has a single reference.

[0037] According to an exemplary embodiment of the invention, an assembly 200, shown in FIGS. 5 to 7, comprises: • a blade 30, • the static blade support 40, • a wedging device 210.

[0038] The blade 30 comprises a root 31 mounted in the wedging device 210. The root 31 is located at a radially internal end of the blade 30 relative to the axis A when the root 31 is mounted in the wedging device 210. The root 31 comprises a first radial face and a second radial face 33 on either side of the root 31. The blade 30 comprises an aerodynamic profile (not shown in the figures) linked to the root 31. The blade 30 is not shrouded in the example of the present description, namely that its free end opposite its root is free by not being contained in a casing.

[0039] The foot 31 further comprises a first lateral face 34a and a second face lateral 34b each connecting the first radial face and the second radial face 33.

[0040] The root 31 further comprises a face 37 connecting the two lateral faces 34a, 34b as well as the two radial faces 33. The face 37 is the surface of the root 31 closest to the static blade support 40.

[0041] The foot 31 is for example in the shape of a dovetail.

[0042] The wedging device 210 comprises: • A 13-inch turntable, • A fixed jaw 11 secured to the plate 13, • A movable jaw 21,

[0043] The plate 13 is disc-shaped. The fixed jaw 11 is integral with the plate 13.

[0044] The fixed jaw 11 is located on a contact surface 14 of the plate 13.

[0045] The fixed jaw 11 comprises a first outer circular surface 113. The first circular surface 113 is a half-cylinder. The movable jaw 21 comprises a second circular surface 213 of identical dimensions to the first circular surface 113. The first circular surface 113 of the fixed jaw 11 and the second circular surface 213 of the movable jaw 21 together form a cylindrical surface having a diameter identical to the diameter of the plate 13.

[0046] The plate 13 comprises a hollow cylinder 17. The hollow cylinder 17 is in pivot connection of axis B with the static blade support 40 by means of ball bearings 4L. The hollow cylinder 17 comprises a shoulder 171 positioned on one of the ball bearings 4L. The pivot connection between the hollow cylinder 17 and the static blade support 40 can also be carried out for example using bushings or using plain bearings.

[0047] One end of the hollow cylinder 17 is located in the center of a flat surface 162 of the plate 13. The flat surface 162 is parallel to the contact surface 14. The hollow cylinder 17 is integral with the plate 13.

[0048] The contact surface 14 is in surface contact with the face 37 of the blade 30.

[0049] The fixed jaw 11 comprises a first bearing surface 12 in surface contact with the second side face 34b of blade 30.

[0050] The movable jaw 21 is removable from the wedging device 210. The movable jaw 21 has a shape identical to the fixed jaw 11. The movable jaw comprises a second bearing surface 22 in surface contact with the first lateral face 34a of the blade 30.

[0051] With reference to [Fig. 5] which is a top sectional view of the blade 30 of the assembly 210, the fixed jaw 11 comprises, at a contact zone with the movable jaw 21, a first opening 111 allowing the blade 30 to pass. Similarly, the movable jaw 21 comprises, at the contact zone, a second opening 112 allowing the blade 30 to pass. The first 111 and the second opening 112 are of a shape complementary to the blade 30, for example a rectangular shape. tangular.

[0052] With reference to [Fig.7], which is a sectional view of [Fig.6] along the section plane VV, the fixed jaw 11 has two holes 15 opening out located on either side of the foot 31. The axes of the holes 15 of the fixed jaw 11 are parallel to each other and parallel to the contact surface 14.

[0053] Similarly, the movable jaw 21 has two holes 25 opening out located on either side of the foot 31. The axes of the holes 25 of the movable jaw 21 are parallel to each other and parallel to the contact surface 14.

[0054] Each hole 15 of the fixed jaw 11 is aligned with the hole 25 of the movable jaw 21. The fixed jaw 11 is connected to the movable jaw 21 by a fixing means such as for example a screw 70 passing through the hole 15 of the fixed jaw 11 and the hole 25 of the movable jaw 21.

[0055] In an alternative embodiment, the hole 15 of the fixed jaw 11 is tapped. The screw 70 is screwed into the tapping of the hole 15 of the fixed jaw 11.

[0056] In an alternative embodiment, the hole 25 of the movable jaw 21 is tapped. The screw 70 is screwed into the tapping of the hole 25 of the movable jaw 21.

[0057] In an alternative embodiment, the screw 70 is mounted on a nut 72 making it possible to establish a bolted connection with the fixed jaw 11 and the movable jaw 21.

[0058] The holes 15 of the fixed jaw 11 each have a first cavity 18 allowing a head 71 of the screw 70 and / or the nut 72 to be embedded. Similarly, the holes 25 of the movable jaw 21 have a cavity 28 allowing the head 71 of the screw 70 and / or the nut 72 to be embedded. The cavities 18, 28 are made by countersinking, that is to say a flat-bottomed drilling serving to ensure the bearing surface of a screw head, a nut or a washer.

[0059] The first cavities 18 of the fixed jaw 11 also each have a first flat bottom 19 allowing the head 71 of the screw 70 and / or a nut 72 to come into abutment. Similarly, the second cavities 28 of the movable jaw 21 also each have a second flat bottom 29 allowing the head 71 of the screw 70 and / or a nut 72 to come into abutment.

[0060] The fixed jaw 11 comprises a first bearing surface 114 in surface contact with a second bearing surface 214 of the movable jaw 21. The bearing surfaces 114, 214 are flat and parallel to each other. The first bearing surface 114 is between the first circular surface 113 and the first opening 111. Similarly, the second bearing surface 214 is between the second circular surface 114 and the second opening 112.

[0061] As shown in [Fig. 11], a first variant of a method of mounting 300 of the assembly 200 according to the exemplary embodiment of the invention comprises: • a step 301 of the assembly method 300 comprising positioning the second lateral face 34b of the foot 31 on the first bearing surface 12 of the fixed jaw 11, • a step 302 of the assembly method 300 comprising placing the second movable jaw 21 on the plate 13, • a step 302' of the assembly method 300 comprising positioning the second bearing surface 22 of the movable jaw 21 on the first lateral face 34a, • a step 303 of the assembly method 300 comprising a connection of the fixed jaw 11 with the movable jaw 21 by means of the screws 70, • a step 304 of the assembly method 300 comprising the linear movement of the movable jaw 21 towards the fixed jaw 11 by tightening the screws 70, • a sub-step 304' of bringing the foot 31 into contact with the plate 13 following the linear movement of the movable jaw 21 during step 304. During this sub-step 304', the foot 31 moves linearly along the second bearing surface 22 of the movable jaw 21. The sub-step of bringing the foot 31 into contact with the plate 13 takes place between step 304 and step 305. • a step 305 of the assembly method 300 of locking the connection between the fixed jaw 11 and the movable jaw 21 by tightening the screws 70.

[0062] Step 304 of linear displacement of the movable jaw 21 is carried out by tightening the screw 70 in a nut 72 or in a tapped hole. Thus, this step 304 makes it possible to bring the movable jaw 21 closer to the fixed jaw 11 but also to tighten the assembly 200 until the face 37 of the foot is in contact with the plate 13. During step 304, the movable jaw 21 translates on the contact surface 14.

[0063] As shown in [Fig. 12], a second variant of the method of a method of mounting 300 of the assembly 200 according to the exemplary embodiment of the invention comprises: • step 302 of the assembly method 300 comprising placing the second movable jaw 21 on the plate 13, • a sub-step 310 of positioning the foot 31 such that the contact surface 14 of the plate 16 is in contact with the face 37 of the foot 31. • step 301 of the assembly method 300 comprising positioning the second lateral face 34b of the foot 31 on the first bearing surface 12 of the fixed jaw H, • step 303 of the assembly method 300 comprising a connection of the fixed jaw 11 with the movable jaw 21 by means of the screws 70, • step 304 of the assembly method 300 comprising the linear movement of the movable jaw 21 towards the fixed jaw 11 by tightening the screws 70, • step 305 of the assembly method 300 for locking the connection between the fixed jaw 11 and the movable jaw 21 by tightening the screws 70.

[0064] Step 301 of positioning the foot 31 is carried out when the two jaws 11, 21 are separated from each other so as to insert the foot 31.

[0065] The invention also comprises a method for dismantling the assembly 200 comprising: • a first step of the disassembly process comprising unlocking the connection between the fixed jaw 11 and the movable jaw 21 by loosening the screw 70. • a second step of the disassembly process comprising the removal of the movable jaw 21, • a third step of the disassembly process comprising the removal of the foot 31 from the fixed jaw 21.

[0066] The invention is presented for an unducted blade for a 500 engine with an unducted propeller. The present invention can also be used for any turbomachine architecture having an unducted blade and in which centrifugal forces are absent.

Claims

Claims

1. Assembly (200) comprising: - a blade (30) comprising a root (31), - a static blade support (40), - a wedging device (210) linked to the static blade support (40) characterized in that the wedging device comprises: • a plate (13), • a fixed jaw (11) comprising a first bearing surface (12), the fixed jaw (11) is integral with the plate (13), • a movable jaw (21) comprising a second bearing surface (22), the fixed jaw (11) is linked to the movable jaw (21) by a fixing means, the root (31) is in surface contact with: - the first bearing surface (12), - the second bearing surface (22) and - a contact surface (14) of the plate (13).

2. Assembly (200) according to the preceding claim characterized in that the movable jaw (21) is removable from the wedging device (210).

3. Assembly (200) according to one of the preceding claims, characterized in that the fixed jaw (11) and the movable jaw (21) each comprise two holes (15, 25), each hole (15) of the fixed jaw (11) is aligned with a hole (25) of the movable jaw (21), the fixing means is composed of two screws (70), each screw (70) passes through the hole (15) of the fixed jaw (11) and the hole (25) of the corresponding movable jaw (21) of the wedging device (210).

4. Assembly (200) according to one of the preceding claims, characterized in that the wedging device (210) is connected to the blade support (40) via a pivot connection.

5. Assembly (200) according to one of the preceding claims, characterized in that it comprises a plurality of blades (30), each of the blades (30) is secured to the fixed blade support (40) by a wedging device (210).

6. Method of mounting (300) the assembly (200) according to one of the claims- preceding indications characterized in that it comprises: - a step (301) of the assembly method (300) comprising a placement of the root (31) of the blade (30) in contact with the fixed jaw (11), - a step (302) of the assembly method (300) comprising a placement of the second movable jaw (21) on the plate (13), - a step (303) of the assembly method (300) comprising a connection of the fixed jaw (11) with the movable jaw (21) by the fixing means, - a step (304) of the assembly method (300) comprising the linear displacement of the movable jaw (21) towards the fixed jaw (11) by the fixing means, - a step (305) of the assembly method comprising the locking of the connection between the fixed jaw (11) and the movable jaw (21) by the fixing means.

7. Mounting method (300) according to claim 6 characterized in that it comprises between the step (304) of linear displacement of the movable jaw and the step (305) of locking the connection: - a sub-step (304') of bringing the foot (31) into contact with the plate (13) following the linear displacement of the movable jaw (21) during the step (304) of linear displacement of the movable jaw.

8. Mounting method (300) according to claim 6 characterized in that it comprises before the step (301) of placing the foot (31) in contact with the fixed jaw (11): - a sub-step (310) of placing the foot (31) in contact with the plate (13)

9. Method for dismantling the assembly (200) according to one of claims 1 to 5, characterized in that it comprises: - a first step of the dismantling method comprising the unlocking of the connection between the fixed jaw (11) and the movable jaw (21), - a second step of the disassembly method comprising the removal of the movable jaw (21) - a third step of the disassembly method comprising the removal of the blade 30.

10. Turbomachine comprising an assembly (200) according to one of claims 1 to 5.

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