Angular adjustment assembly provided with a worm screw and a fixing nut for an adjustable orientation blade and associated adjustment method

Abstract

Angular adjustment assembly with wheel and worm screw for variable pitch blade and associated adjustment method One aspect of the invention relates to an angular adjustment assembly (20) for an adjustable pitch blade (210) comprising: a hub (200), a blade (210) mounted so as to be able to rotate in the hub, a device for adjusting the rotation of the blade. The adjustment device comprises: a worm screw (242) comprising a threaded rod (243) received in the hub and a base (220) of the blade, and a head (244), a fixing nut (250) mounted so as to be able to rotate in a fitted hole (222) of the base and comprising a tapped hole (252) receiving the threaded rod, the fixing nut being mounted so as to be able to move in translation on the threaded rod, an axial locking part (266) for the screw, a means for locking the screw in rotation and a means for rotating the worm screw. Figure to be published with the abstract: Figure 2

Description

Title of the invention: Angular adjustment assembly provided with a worm screw and a fixing nut for a blade with adjustable orientation and associated adjustment method TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of aircraft turbomachines and testing machines for the development of aircraft turbomachines.

[0002] The present invention relates to an angular adjustment assembly for an adjustable orientation blade of a turbomachine or turbomachine testing machine. It also relates to a turbomachine and a turbomachine testing machine comprising such an angular adjustment assembly, as well as an adjustment method using such an angular adjustment assembly. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] Conventionally, aircraft turbomachines have adjustable pitch blades, also called variable pitch blades or pivoting blades. Adjustable pitch blades are configured to pivot about their axis of rotation, in order to adjust their angular position (their angle of attack) relative to the airflow passing through them and thus optimize the airflow in the turbomachine.

[0004] There are stator stages of variable-pitch vanes arranged between the moving wheels of turbomachine compressors. These may also be flow straightening vanes arranged downstream of the fan, called outlet guide vanes or OGV vanes (Outlet guide vanes in English).

[0005] Such blades are carried by a stator casing and can be pivoted during engine operation, which makes it possible to optimize their action according to the engine speed and flight conditions. Since the performance of the turbomachine relies on the precision of the angular positioning of these blades relative to the casing, the adjustment of the angular position must be rapid, precise, reliable and repeatable.

[0006] In the prior art, the adjustable orientation blades are extended at their outer end by a radial control rod which passes through an opening in the outer casing. Control rods are fixed laterally to the free ends of these control rods and are connected by their other end to a rotating crown located outside the casing. An electric, pneumatic or hydraulic servo system automatically controls the rotation of the crown according to the operating conditions, which causes the pivoting of the rods and thus the modification of the inclination of the adjustable orientation blades.

[0007] For this system to be functional, the coupling between the control rod and the The connecting rod of a blade must be precise in addition to having to withstand significant torques. In addition, the adjustment during assembly of the orientation of the blade relative to the connecting rod must be particularly fine.

[0008] An objective of the invention is to propose an assembly for alternative angular adjustment of variable-pitch blades, usable in a turbomachine, mechanically simplified and which is at the same time fast, precise, reliable and repeatable.

[0009] There are also adjustable orientation blades in testing machines for the development of aircraft turbomachines. These testing machines make it possible to test the aerodynamic and acoustic behavior of the various elements of the turbomachine and in particular to determine the optimal angular positioning of the moving blades of the rotors and the fixed blades of the stators to obtain the best possible performance.

[0010] The testing machines therefore conventionally include blades with adjustable orientation in order to be able to simulate a precise angular positioning of these blades and / or test different positions depending on the result of the tests.

[0011] Currently, in testing machines, the angular adjustment of adjustable orientation blades is done manually by an operator using complex tools to measure the displacement of the blade and thus position it with the desired setting angle. This operation is long and meticulous and must be carried out blade by blade by an experienced operator.

[0012] An objective of the invention is to propose an assembly for alternative angular adjustment of variable-pitch blades, usable in a testing machine, which is simple, rapid, precise, reliable and repeatable. Summary of the invention

[0013] The invention offers a solution to the problems mentioned above by proposing an assembly for angular adjustment of a blade with adjustable orientation of a turbomachine or turbomachine testing machine with axis Al having a particular architecture.

[0014] A first aspect of the invention relates to an angular adjustment assembly comprising: • a hub comprising a first face and a second face opposite each other along the axis Al, • an adjustable orientation blade comprising a base and a blade extending radially from the base, the base of the adjustable orientation blade being mounted so as to be able to rotate in the hub relative to an axis A2 perpendicular to the axis A1; and • a device for adjusting the rotation of the blade with adjustable orientation around the axis A2,

[0015] The adjustment device comprises: • an endless screw with axis A3 parallel to the axis Al, comprising: • a threaded rod received in a through hole of the hub extending from its first face to its second face, and in a recess of the base of the blade with adjustable orientation, the threaded rod being free in translation in a direction T2 perpendicular to the axes A2 and A3, and • a head resting against the first face of the hub, • a fixing nut having a circular section, the fixing nut being mounted so as to be able to rotate in a hole fitted in the base relative to an axis A4 parallel to the axis A2 and perpendicular and intersecting the axis A3, and comprising a tapped hole with axis A3 receiving the threaded rod of the worm screw, the fixing nut being mounted so as to be able to move in translation on the threaded rod of the worm screw, • an axial locking part for the worm screw relative to the hub, • a means of locking the worm screw in rotation relative to the hub, And • a means of rotating the worm screw.

[0016] Such an angular adjustment assembly can be used both in an aircraft turbomachine and in an aircraft turbomachine testing machine.

[0017] In a turbomachine, the angular adjustment assembly can, for example, make it possible to adjust the angular position of the outlet guide vanes or the adjustable orientation vanes of the compressors in order to adapt their angular positioning to the engine speed and the flight conditions and thus to optimize the operation of the turbomachine.

[0018] In a test machine, the angular adjustment assembly can make it possible to adjust the angular position of any blade whose angular orientation has been provided to be adjustable in the test machine (this blade being able to be fixed once installed in a turbomachine). Different angular positions of this blade can thus be tested by means of the test machine and it is possible to define an aerodynamically optimal angular position (an optimal pitch angle) to be reproduced subsequently in the turbomachine to improve performance.

[0019] The invention provides an angular adjustment assembly by a combination of a worm screw with a fixing nut which is reliable and mechanically simple. Such an angular adjustment assembly makes it possible to adjust the angular position of the adjustable orientation vane in a simple and rapid manner, without the need to disassemble parts beforehand to achieve this.

[0020] According to a first example embodiment of the adjustment device, the fixing nut is a cylinder with axis A4.

[0021] According to a second exemplary embodiment of the adjustment device, the fixing nut is a sphere.

[0022] Advantageously, the locking part is arranged to bear against the first face of the hub and comprises a housing in which the head of the worm screw is free in translation along the face, in the direction T2. ​​Such a characteristic allows the rotation of the base of the blade with adjustable orientation relative to the hub and thus the angular adjustment of the blade with adjustable orientation.

[0023] Preferably, the locking means comprises a nut arranged at one end of the threaded rod of the worm screw, opposite the second face of the hub.

[0024] Advantageously, the recess in the base of the adjustable orientation blade is open in a direction perpendicular to the axes A3 and A4. Such a characteristic allows the rotation of the base of the adjustable orientation blade relative to the axis A3 without coming into contact with the threaded rod of the worm screw.

[0025] A second aspect of the invention relates to a system for angular adjustment of a crown of blades with adjustable orientation of a turbomachine or turbomachine testing machine, which comprises an angular adjustment assembly according to the first aspect of the invention for each of the blades with adjustable orientation.

[0026] Advantageously, such an adjustment system may further comprise a device for synchronizing the rotation of the threaded rods of the worm screws of the angular adjustment assemblies.

[0027] The synchronization device makes it possible to coordinate the rotation of the threaded rods of all the worm screws and therefore the movement of all the fixing nuts of the different angular adjustment assemblies with each other so that they are actuated simultaneously and in the same way. The angular position of each adjustable orientation blade of the blade ring can thus be modified in a synchronized manner, that is to say simultaneously and in the same way.

[0028] A third aspect of the invention relates to an aircraft turbomachine comprising at least one angular adjustment assembly according to the first aspect of the invention.

[0029] A fourth aspect of the invention relates to a turbomachine testing machine comprising at least one angular adjustment assembly according to the first aspect of the invention.

[0030] A fifth aspect of the invention relates to a method for angular adjustment of a variable-pitch blade, carried out by means of an angular adjustment assembly and comprising the following steps: • unlocking of the worm screw by the locking means of the adjustment device, • rotation of the threaded rod of the worm screw of the adjustment device until that at a desired position of the adjustable orientation vane relative to the hub, and • locking of the worm screw by the locking means of the adjustment device.

[0031] 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

[0032] Other advantages and characteristics of the invention will appear on reading the following description, illustrated by the figures in which:

[0033] [Fig. 1] is a partial sectional view of a testing machine comprising a angular adjustment assembly, according to the invention;

[0034] [Fig.2] is a longitudinal front section of an example of the adjustment assembly angular according to a section plane II-II of [Fig.5] comprising an adjustment device, according to the invention;

[0035] [Fig.3] is a longitudinal section from above of the angular adjustment assembly according to a plane III-III of [Fig.2], in a first position of the adjustment device;

[0036] [Fig.4] is a view similar to that of [Fig.2], in a second position of the adjustment device;

[0037] [Fig.5] is a side cross-section of the angular adjustment assembly according to a VV plane of [Fig.2]. DETAILED DESCRIPTION

[0038] Unless otherwise specified, the same element appearing in different figures has a single reference.

[0039] In the description, the terms "upstream" and "downstream" are defined with respect to the normal flow direction of the gas (from upstream to downstream) through a turbomachine or a turbomachine testing machine. In addition, the terms "axis of the turbomachine" or "axis of the testing machine" designate the axis of rotation of the rotor of the turbomachine or the testing machine, this axis being designated A1 in the figures.

[0040] [Fig.l] shows a turbomachine test machine 10 configured to simulate an aircraft turbomachine and test its components under different aerodynamic conditions in order to study their performance.

[0041] The test machine 10 according to an example as shown in [Fig.l] comprises: • a fan 12 comprising a crown of moving blades 14, • a rectifier stator crown 16 arranged downstream of the crown of mobile blades 14 and comprising: • 200 hubs, and • 210 OGV type adjustable orientation blades (one of which has been framed in figure 1) each being mounted mobile in rotation in one of the hubs 200, relative to an axis A2 perpendicular to the axis Al, and • at least one angular adjustment assembly 20 of one of the adjustable orientation blades 210.

[0042] As shown in [Fig.l], an angular adjustment assembly 20 is advantageously installed for each of the adjustable orientation blades 210. All the angular adjustment assemblies 20 of the straightening stator ring 16 can advantageously be associated with a synchronization device and together form an angular adjustment system 18 for the straightening stator ring 16 of adjustable orientation blades 210.

[0043] Such an angular adjustment assembly 20 can also be installed in a turbomachine.

[0044] According to an example as shown in Figures 2 to 5, each angular adjustment assembly 20 comprises: • a single hub 200 comprising a first face 202A and a second face 202B opposite each other along the axis A1 and an external face 203 connecting the first and second faces 202A, 202B to each other, • a single blade with adjustable orientation 210 comprising: • a base 220 mounted to rotate in the hub 200 relative to the axis A2, and • a blade 230 extending radially from the base, • a device 240 for adjusting the rotation of the adjustable orientation blade 210 around the axis A2.

[0045] The adjustable orientation blade 210 is mounted to rotate freely around the axis A2 so as to modify the angular orientation of the blade 230 relative to the hub 200 according to several positions of the blade 230.

[0046] The base 220 of the adjustable orientation blade 210 is engaged in a housing 206 of the hub 200. As shown in [Fig. 2], the base 220 comprises two coaxial cylindrical portions, a first portion 220A extending from its surface in contact with the blade 230 along the axis A2 and before the axis A3 and a second portion 220B extending from the first portion 232A along the axis A2 and beyond the axis A3. The difference in diameter between the first and second portions 220A, 220B of the base 220 forms a shoulder.

[0047] The housing 204 of the hub 200 has a shape complementary to that of the base 220 and is open in the external face 203 of the hub 200. As shown in [Fig. 2], the housing 204 comprises two coaxial cylindrical portions, a first portion 204A of which extends from the external face 203 of the hub 200 along the axis A2 and before the axis A3 and a second portion 204B extending from the first portion 204A along the axis A2 and beyond the axis A3. The difference in diameter between the first and second portions 204A, 204B of the housing 204 forms a collar.

[0048] In the engaged position of the base 220 of the adjustable orientation blade 210 in the housing 204 of the hub 200, the first portion 220A of the base 220 is received in the first portion 204A of the hub 200, the second portion 220B of the base 220 is received in the second portion 204A of the hub 200 so that the collar of the housing 204 of the hub 200 bears against the shoulder of the base 220 of the adjustable orientation blade 210 longitudinally retaining the adjustable orientation blade 210 along the axis A1.

[0049] The hub 200 further comprises a through hole 206 extending from its first face 202A to its second face 202B along an axis A3 parallel to the axis AL

[0050] The adjustable orientation blade 210 further comprises: • a recess 224 (visible in [Fig.5]) arranged in the second portion 220B of its base 220 and extending along the axis A3, • an adjusted hole 222 arranged in the second portion 220B of its base 220 and extending along an axis A4 parallel to the axis A2 and perpendicular and intersecting the axis A3.

[0051] As shown in Figures 1 to 4, the recess 224 of the base 220 of the adjustable orientation vane 210 (represented by a dotted line) includes the portion of the threaded rod 243 of the worm screw 242 facing the vase 220 and includes the fixing nut 250 of the adjustment device 240. More particularly, as shown in [Fig. 5], the recess 224 has a length along the axis A4 greater than the diameter of the threaded rod 243 of the worm screw 242 of the adjustment device 240 so that the pivoting of the base 220 of the adjustable orientation vane 210 relative to the axis A3 is not blocked by the worm screw 242. According to a particular example as shown in [Fig. 5], the recess 224 of the base 220 of the adjustable orientation blade 210 is open in a direction perpendicular to the axes A3 and A4.

[0052] The adjustment device 240 according to an example as shown in FIGS. 2 to 5 comprises: • a worm screw 242 with rotation axis A3 parallel to axis Al comprising: • a threaded rod 243 received in the through hole 206 of the hub 200, and in the recess 224 of the base 220 of the adjustable orientation blade 210, the threaded rod 243 comprising a free end 246, and • a head 244 bearing against the first face 202A of the hub 200, • a fixing nut 250 having a circular section and comprising a tapped hole 252 with axis A3 receiving the threaded rod 243 of the worm screw 242, • an axial locking part 266 of the worm screw 242 relative to the hub 200 arranged to bear against the first face 202A of the hub 200 and comprises a housing 268 in which the head 244 of the worm screw 242 is received, • a means 260 for locking the worm screw 242 in rotation relative to the hub 200 comprising: • a nut 264 arranged at the free end 246 of the threaded rod 243 of the worm screw 240, and • a washer 262 arranged between the second face 202B of the hub 200 and the nut 264, and • a means for rotating the worm screw 242 formed by a clamping slot 248 arranged in the free end 246 of the threaded rod 243 of the worm screw 242.

[0053] As illustrated in [Fig. 2], the housing 268 of the locking part 266 has a length along the axis A4 substantially equal to the diameter of the head 244 of the worm screw 242. The length of the housing 268 may also be greater than that of the head 244 of the worm screw 242. As illustrated in [Fig. 4], the housing 268 of the locking part 266 has a width greater than that of the head 244 of the worm screw 242.

[0054] In the mounted position of the adjustment device 240 relative to the hub 200 and the adjustable orientation vane 210: • the worm screw 242 is free in translation in a direction T2 perpendicular to the axes A2 and A3 (visible in figures 2 and 3) so that: • the threaded rod 243 is free in translation in the through hole 206 of the hub 200 in the direction T2, and • the head 244 is free in translation in the housing 268 of the locking part 266 in the direction T2, • the fixing nut 250 is mounted to move in rotation in the adjusted hole 222 of the base 220 relative to the axis A4 (visible in figures 2 and 5), and • the fixing nut 250 being mounted mobile in translation on the threaded rod 243 of the worm screw 242 in a direction Tl parallel to the axis A3 (visible in figures 3 and 4),

[0055] The worm screw 242 of the adjustment device 240 is configured to pivot the adjustable orientation vane 210 around the axis A2 to adjust its angular position. Indeed, the rotation of the threaded rod 243 of the worm screw 242 around its axis A3 causes the translation of the fixing nut 242 in the direction T1 and consequently the translation of the worm screw 242 in the direction T2 and the pivoting of the adjustable orientation vane 210 around the axis A2.

[0056] According to a first example as shown in Figures 2 to 5, the fixing nut 250 of the adjustment device 240 is a cylinder of axis A4, and the adjusted hole 222 of the second portion 220B of the base 220 of the adjustable orientation blade 210 has a cylindrical shape complementary to that of the fixing nut 250 and is open.

[0057] According to a second example not shown, the fixing nut 250 of the adjustment device 240 is a sphere and the adjusted hole 222 of the second portion 220B of the base 220 of the adjustable orientation blade 210 has a spherical shape complementary to that of the fixing nut 250 and is open.

[0058] The tapped hole 252 of the fixing nut 250 of the adjustment device 240 has an internal thread configured to mesh with the threads of the threaded rod 243 of the worm screw 242.

[0059] In the locked position of the locking means 260 of the adjustment device 240 as shown in Figures 2 to 5: • the nut 264 is screwed so that the washer is held against the second face 203 of the hub 200, and • the threaded rod 243 of the worm screw 242 is locked in pivoting around the axis A3, thus fixing the angular orientation of the blade 230 of the adjustable orientation vane 210.

[0060] In the unlocked position of the locking means 260 of the adjustment device 240, not shown: • the nut 264 is unscrewed so that the washer 262 is no longer in contact with the second face 203 of the hub 200, • and the threaded rod 243 of the worm screw 242 is free to pivot around the axis A3.

[0061] Advantageously, the clamping slot 248 formed in the free end 246 of the threaded rod 243 of the worm screw 242 has a hollow shape complementary to the end of a tool configured to be engaged therein so as to drive the worm screw 242 in rotation. The clamping slot 248 may for example have a hollow hexagonal, cruciform, square, slotted or star-shaped shape, complementary to that of a suitable wrench or screwdriver. Depending on the applications, this tool may be manual or automated (by servomotor or other mechanical locking).

[0062] A method for angular adjustment of an adjustable orientation blade 210 carried out by means of an angular adjustment assembly 20 comprises the following steps: • unlocking the worm screw 242 to the unlocked position of the locking means 260 of the adjustment device 240 in which the worm screw 242 is free to rotate relative to the axis A3, • insertion of the end of a tool into the clamping slot 248 of the threaded rod 243 of the worm screw 242 of the adjustment device 240, • rotation of the threaded rod 243 of the worm screw 242 (passage from [Fig.3] to [Fig.4]) causing: • the translation Tl of the fixing nut 242, • rotation of the fixing nut 242 in the adjusted hole 222 of the base of the adjustable orientation blade 210 around the axis A4, • the translation T2 of the worm screw 242, • the pivoting PI of the base 220 of the adjustable orientation blade 210 in the housing 204 of the hub around the axis A2 until the desired setting angle of the adjustable orientation blade 210 relative to the hub 200, and locking the worm screw 242 until the locked position of the locking means 260 of the adjustment device 240 according to which the worm screw 242 is blocked in rotation relative to the axis A3.

Claims

Claims

1. Angular adjustment assembly (20) of an adjustable orientation blade (210) of a turbomachine or of a testing machine (10) of a turbomachine of axis Al, the angular adjustment assembly (18) comprising: - a hub (200) comprising a first face (202A) and a second face (202B) opposite each other along the axis Al, - an adjustable orientation blade (210) comprising a base (220) and a blade (230) extending radially from the base (220), the base (220) of the adjustable orientation blade (210) being mounted to rotate in the hub (200) relative to an axis A2 perpendicular to the axis A1; and - a device (240) for adjusting the rotation of the adjustable orientation blade (210) around the axis A2, characterized in that the adjustment device (240) comprises: - an endless screw (242) with axis A3 parallel to axis Al comprising: • a threaded rod (243) received in a through hole (206) of the hub (200) extending from its first face (202A) to its second face (202B), and in a recess (224) of the base (220) of the adjustable orientation blade (210), the threaded rod (243) being free in translation in a direction T2 perpendicular to the axes A2 and A3, and • a head (244) bearing against the first face (202A) of the hub (200), - a fixing nut (250) having a circular section, the fixing nut (250) being mounted to move in rotation in an adjusted hole (222) of the base (220) relative to an axis A4 parallel to the axis A2 and perpendicular and intersecting the axis A3, and comprising a tapped hole (252) of axis A3 receiving the threaded rod (243) of the worm screw (242), the fixing nut (250) being mounted to move in translation on the threaded rod (243) of the worm screw (242), - an axial locking part (266) of the worm screw (242) by relative to the hub (200), - a locking means (260) for rotation of the worm screw (242) relative to the hub (200), and - a means for rotating the worm screw (242).

2. Angular adjustment assembly (20) according to claim 1, characterized in that the fixing nut (250) of the adjustment device (240) is a cylinder with axis A4.

3. An annular adjustment assembly (20) according to claim 1, characterized in that the fixing nut (250) of the adjustment device (240) is a sphere.

4. Angular adjustment assembly (20) according to any one of the preceding claims, characterized in that the locking part (266) is arranged to bear against the first face (202A) of the hub (200) and comprises a housing (268) in which the head (244) of the worm screw (242) is free in translation along the face (202A), in the direction T2.

5. Angular adjustment assembly (20) according to any one of the preceding claims, characterized in that the locking means (260) comprises a nut (264) arranged at one end (246) of the threaded rod (243) of the worm screw (242), opposite the second face (202B) of the hub (200).

6. Angular adjustment assembly (20) according to any one of the preceding claims, characterized in that the recess (224) of the base (220) of the adjustable orientation blade (210) is open in a direction perpendicular to the axes A3 and A4.

7. Angular adjustment system (18) for a crown (182) of adjustable orientation blades (210) of a turbomachine or turbomachine testing machine (10), characterized in that it comprises an angular adjustment assembly (20) according to any one of claims 1 to 6 for each of the adjustable orientation blades (210).

8. Angular adjustment system (18) according to claim 7 characterized in that it further comprises a device for synchronizing the rotation of the threaded rods (243) of the worm screws (242) of the adjustment device (240) of the angular adjustment assemblies (20).

9. Aircraft turbomachine comprising at least one angular adjustment assembly (20) according to any one of claims 1 to 6.

10. A turbomachine testing machine (10) comprising at least one angular adjustment assembly (20) according to any one of claims 1 to 6.

11. Method for angular adjustment of an adjustable orientation blade (210) characterized in that it is carried out by means of an angular adjustment assembly (20) according to any one of claims 1 to 6 and comprising the following steps: - unlocking the worm screw (242) by the locking means (260) of the adjustment device (240), - rotating the threaded rod (243) of the worm screw (242) of the adjustment device (240) until a desired position of the adjustable orientation blade (210) relative to the hub (200), and - locking the worm screw (242) by the locking means (260) of the adjustment device (240).

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