SYSTEM FOR ADJUSTING THE ROTATION OF A BLADE OF A FAN MODULE BY AN EXTERNAL SCREW

Abstract

The invention relates to an aircraft turbomachine module, in particular for a test bench, comprising: - an annular hub (10), - at least one blade (11), and - a system (17) for adjusting the rotation of the blade (11) comprising: - an adjusting screw (19) having one end screwed into a threaded bore (20) made in the blade root (13), so that the adjusting screw (19) is linked in rotation with the blade root (13), - a flange (21) fixed on a face of the annular hub (10), so that loosening the adjusting screw (19) allows angular movement of the blade (11) along the oblong opening (23) of the flange (21) so as to be able to choose a desired angular position, and tightening the adjusting screw (19) makes it possible to immobilize the blade (11) in the desired angular position.

Description

Title of the invention: SYSTEM FOR ADJUSTING THE ROTATION OF A BLADE OF A FAN MODULE BY AN EXTERNAL SCREW

[0001] The present invention relates to a system for adjusting the rotation of a blade of a fan module by an external screw. The invention finds a particularly advantageous, but not exclusive, application with a fan rectifier module.

[0002] The operating principle of a turbomachine fan is to compress the air entering the engine. Part of this air constitutes the primary flow delimited by a primary vein and another part of this air constitutes the secondary flow delimited by a secondary vein. The primary flow passes through a low-pressure compressor integral with the fan, through a high-pressure compressor, through the combustion chamber, through the high-pressure turbine and, finally, through the low-pressure turbine before being ejected.

[0003] The present invention relates in particular to a test machine for a test bench, for example a fan of an aerodynamic demonstrator which has only a single air flow and which does not have a low pressure compressor, nor a high pressure compressor or a combustion chamber. Such a test machine aims to test different parts of the turbomachine and to optimize the operating settings of the turbomachine.

[0004] [Fig.l] shows a test machine 1 for a test bench comprising from upstream to downstream, an upstream flow vein 2, a fan 3 having a rotor module 4 with moving blades and a rectifier module 5 with fixed blades called OGV (for "Outlet Guide Vane" in English), as well as a downstream flow vein 6.

[0005] The rotor module 4 comprises a plurality of blades mounted on a cylindrical hub called a "fan disc" driven in rotation by a pressure turbine supplied with air by the test bench. The rotor module 4 provides acceleration to the air particles, by deflecting them relative to the X axis of the engine. The rectifier module 5 slows down the air particles and transforms part of their speed into pressure. The rectifier module 5 brings the flow of air, accelerated by the rotor module 4, back into the X axis of the engine.

[0006] During a test campaign, it is important to be able to ensure rapid assembly and disassembly of a blade as well as modification of its angular setting in order to find an optimum setting of the turbomachine. There is therefore a need to be able to carry out these operations as quickly as possible in order to limit the downtime of the test machine during a test campaign. These operations must can also be carried out without having to dismantle the test machine which is fully instrumented.

[0007] The invention aims to effectively meet the aforementioned needs by proposing an aircraft turbomachine module, in particular for a test bench, comprising: - an annular hub comprising at least one blade root housing, - at least one blade provided with a blade root intended to be arranged inside the blade root housing, said blade having an axis, - a blade rotation adjustment system comprising: - an adjusting screw having one end screwed into a threaded bore made in the blade root, so that the adjusting screw is rotationally connected to the blade root, - a flange fixed on one face of the annular hub, said flange comprising an oblong opening, - the adjusting screw being inserted inside the oblong opening of the flange and a through window made in the wall of the hub, so that loosening the adjusting screw allows angular movement of the blade following the oblong opening of the flange so as to be able to choose a desired angular position, and tightening the adjusting screw allows the blade to be immobilized in the desired angular position.

[0008] The invention thus makes it possible to easily modify the angular setting of the blade between two tests without having to dismantle the test machine. The invention makes it possible to limit downtime during the test as much as possible. The invention allows the adjustment of the setting of the blade while remaining in a dimensionally constrained environment. The invention also respects the aerodynamic profile of the vein regardless of the position of the blade, the vibrations, or its internal displacements due to pumping phenomena or transient flows during a change of setting. In the event of breakage of a blade, the invention also makes it possible to facilitate in situ disassembly. The invention also has the advantage of being a simple solution to implement containing a minimum of parts.

[0009] According to one embodiment of the invention, the adjustment screw has a radial orientation relative to an axis of the blade.

[0010] According to one embodiment of the invention, the adjustment screw is associated with a washer.

[0011] According to one embodiment of the invention, the flange has a convex shape and the washer has a complementary concave shape.

[0012] According to one embodiment of the invention, the convex flange and the concave washer have a radius of curvature having one end passing through the axis of the blade.

[0013] According to one embodiment of the invention, the flange comprises two fixing lugs each intended to receive a fixing member for fixing the flange to the annular hub.

[0014] According to one embodiment of the invention, the assembly formed by a head of the adjustment screw, the washer and the flange is arranged inside a housing located under a vein of the module.

[0015] According to one embodiment of the invention, said module comprises an access cover reconstituting the vein allowing access to the adjustment screw to modify an angular position of the blade.

[0016] According to one embodiment of the invention, the annular hub is a single-piece hub.

[0017] According to one embodiment of the invention, the module is a rectifier module.

[0018] The present invention will be better understood and other characteristics and advantages will become apparent upon reading the detailed description which follows, comprising embodiments given for illustrative purposes with reference to the appended figures, presented as non-limiting examples, which may serve to complete the understanding of the present invention and the description of its embodiment and, where appropriate, contribute to its definition, in which:

[0019] [Fig-1] [Fig.l], already described, is a longitudinal sectional view of a machine of test with which the invention is implemented;

[0020] [Fig.2] [Fig.2] is a perspective view of a rectifier module for a bench aircraft turbomachine testing according to the present invention;

[0021] [Fig.3] [Fig.3] is a schematic sectional view of a blade and a system of rotational adjustment of a blade according to the invention;

[0022] [Fig.4] [Fig.4] is a detailed sectional view of a blade foot and a system of rotational adjustment of a blade according to the invention;

[0023] [Fig.5] [Fig.5] is a detailed perspective view of an adjustment system in rotation of a blade according to the invention;

[0024] [Fig.6a] [Fig.6b] Figures 6a and 6b are top views illustrating two positions angular which can be taken by a blade thanks to the rotation adjustment system of a blade according to the invention.

[0025] It should be noted that in the figures the structural and / or functional elements common to the different embodiments have the same references. Thus, unless otherwise stated, such elements have identical structural, dimensional and material properties.

[0026] [Fig.2] shows a rectifier module 5 for a turbomachine test bench aircraft comprising an annular hub 10 having an axis XI and a plurality of blades 11.

[0027] The annular hub 10 comprises a plurality of blade root housings 12. Advantageously, the annular hub 10 is a single-piece hub. Alternatively, the annular hub 10 may be formed by two coaxial annular elements fixed to each other and defining between them the housings 12 of blade roots 11.

[0028] The blades 11 extend radially along their axis Y towards the outside of the hub 10. The blades 11 are distributed angularly in a regular manner along a circumference of the hub 10. Each blade 11 is provided with a blade root 13 of generally cylindrical shape intended to be arranged inside a corresponding blade root housing 12. A large diameter portion of the blade root 13 can come to bear against a shoulder 15 of the housing 12 intended to ensure radial retention of the blade root 13 relative to the axis XI, as shown in [Fig.4].

[0029] A rotation adjustment system 17 of the blade 11 makes it possible, in an unlocked state, to authorize a rotation of the blade root 13 inside a corresponding housing 12 around the Y axis so as to select a desired angular position of the blade 11 for a test and, in a locked state, to immobilize the blade 11 inside the housing 12 in the desired angular position.

[0030] For this purpose, as illustrated in Figures 3, 4, and 5, the rotation adjustment system 17 of the blade 11 comprises an adjustment screw 19 cooperating with a flange 21 by means of a washer 25 arranged between the head of the adjustment screw 19 and the flange 21.

[0031] More precisely, the adjusting screw 19 has an end screwed into a threaded bore 20 made in the blade root 13, so that the adjusting screw 19 is linked in rotation with the blade root 13. The adjusting screw 19 has a radial orientation relative to an axis Y of the blade 11. The adjusting screw 19 is preferably associated with a washer 25.

[0032] The flange 21 is fixed on one face of the annular hub 10. In this case, the flange 21 is fixed on an axial end face of the annular hub 10. For this purpose, as can be seen in [Fig. 5], the flange 21 comprises two fixing lugs 27 each intended to receive a fixing member for fixing the flange 21 on the annular hub 10. The fixing members can take the form of screws, rivets or any other fixing member suitable for the application.

[0033] As can be seen in Figures 5, 6a and 6b, the flange 21 has an oblong opening 23. The adjusting screw 19 is inserted inside the oblong opening 23 of the flange 21 and a through window 24 made in the wall of the hub 10. The through window 24 opens on the one hand into the blade root housing 12 opposite the tapped bore 20 and on the other hand on the side of an end face of the hub 10. A width L1 of the through window 24 is substantially equal to a length L2 of the oblong opening of the flange 21, as shown in [Fig.6a].

[0034] Advantageously, the flange 21 has a convex shape and the washer 25 has a complementary concave shape. The convex flange 21 and the concave washer 25 have a radius of curvature Rc having one end passing through the axis Y of the blade 11.

[0035] The operation of the rotation adjustment system 17 according to the invention is described below.

[0036] As illustrated by [Fig.6a] and 6b, loosening the adjustment screw 19 allows angular movement of the blade 11 along the oblong opening 23 of the flange 21 so as to be able to choose a desired angular position. The angular movement of the blade 11 is carried out around an axis of rotation corresponding to the Y axis of the blade 11 or an axis of the blade root 13, the two axes possibly being the same.

[0037] When the blade 11 is in the desired angular position, tightening the adjustment screw 19 against the flange 21 via the washer 25 makes it possible to immobilize the blade 11 in this angular position. It is then possible to carry out tests of the fan according to this configuration of the stator module. Alternatively, the washer 25 is removed so that the adjustment screw 19 is tightened directly against the flange 21 to maintain the blade 11 in the desired angular position.

[0038] The operations of handling the blade 11 and tightening or loosening the adjustment screw 19 can be carried out by a human operator or automatically by a robot.

[0039] The invention thus makes it possible to quickly modify the timing of the blades 11 between two tests. The invention makes it possible to limit downtime during the test as much as possible. The invention allows the adjustment of the timing of the blade while remaining in a dimensionally constrained environment. Furthermore, in the event of breakage of a blade 11, disassembly can be carried out in situ, which constitutes a significant time saving.

[0040] The assembly formed by a head of the adjustment screw 19, the washer 25 and the flange 21 is arranged inside a housing located under a vein of the fan module.

[0041] An access cover 28 reconstituting the vein allows access to the adjustment screw 19 to modify an angular position of the blade 11. This guarantees an optimum vein profile due to the continuity of the surface between the blade root and the hub 10. This avoids any interference with the aerodynamic flow of the vein.

[0042] The invention respects the aerodynamic profile of the vein whatever the position of the blade, the vibrations, or its internal movements due to pumping phenomena or transient flows during a change of setting.

[0043] The invention guarantees mechanical strength of the parts and the assembly at all operating speeds of the turbomachine.

[0044] The invention also has the advantage of being a simple solution to implement containing a minimum of parts.

[0045] Alternatively, the fan module 5 may be a rotor module.

[0046] Of course, the various features, variants and / or embodiments of the present invention may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive. of others.

[0047] Furthermore, the invention is not limited to the embodiments described above and provided solely by way of example. It encompasses various modifications, alternative forms and other variants that may be envisaged by those skilled in the art within the scope of the present invention and in particular all combinations of the different operating modes described above, which may be taken separately or in association.

Claims

Claims

1. Aircraft turbomachine module (5), in particular for a test bench, comprising: - an annular hub (10) comprising at least one blade root housing (12), - at least one blade (11) provided with a blade root (13) intended to be arranged inside the blade root housing (12), said blade (11) having an axis (Y), characterized in that said module (5) comprises a system (17) for adjusting the rotation of the blade (11) comprising: - an adjusting screw (19) having one end screwed into a threaded bore (20) made in the blade root (13), so that the adjusting screw (19) is linked in rotation with the blade root (13), - a flange (21) fixed on a face of the annular hub (10), said flange (21) comprising an oblong opening (23), - the adjusting screw (19) being inserted inside the oblong opening (23) of the flange (21) and a through window (24) made in the wall of the hub (10),so that loosening the adjustment screw (19) allows angular movement of the blade (11) along the oblong opening (23) of the flange (21) so as to be able to choose a desired angular position, and tightening the adjustment screw (19) allows the blade (11) to be immobilized in the desired angular position.

2. Module according to claim 1, characterized in that the adjusting screw (19) has a radial orientation relative to the axis (Y) of the blade (H).

3. Module according to claim 1 or 2, characterized in that the adjusting screw (19) is associated with a washer (25).

4. Module according to claim 3, characterized in that the flange (21) has a convex shape and the washer (25) has a complementary concave shape.

5. Module according to claim 4, characterized in that the convex flange (21) and the concave washer (25) have a radius of curvature (Rc) having one end passing through the axis of the blade (11).

6. Module according to any one of claims 1 to 5, characterized in that the flange (21) comprises two fixing lugs (27) each intended to receive a fixing member for fixing the flange (21) to the annular hub (10).

7. Module according to any one of claims 1 to 6, characterized in that the assembly formed by a head of the adjustment screw (19), the washer (25) and the flange (21) is arranged inside a housing located under a vein of the module.

8. Module according to claim 7, characterized in that it comprises an access cover (28) reconstituting the vein allowing access to the adjustment screw (19) to modify an angular position of the blade (11).

9. Module according to any one of claims 1 to 8, characterized in that the annular hub (10) is a single-piece hub.

10. Module according to any one of claims 1 to 9, characterized in that the module is a rectifier module (5).

Images