SYSTEM FOR ROTATIONALLY LOCKING A BLADE OF A FAN MODULE BY AN INSERT

Abstract

The invention relates to an aircraft turbomachine module, in particular for a test machine, 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), and - a system (15) for locking the blade (11) in rotation, comprising: - a split insert (16) having an external face (17) of conical shape and an opening (18) in which the blade root (13) is arranged, - a platform (21) provided with a through hole (22) in which the split insert (16) is inserted, said through hole (22) being delimited by an internal face having a conical shape of a shape complementary to the external face (17) of the split insert (16), and - at least one fixing member (25) capable of fixing the platform (21) on the annular hub (10),so that tightening of the fixing member (25) ensures compression of the split insert (16) between the platform (21) and the blade root (13) so as to lock the blade (11) in a desired angular position. Figure 4,

Description

Title of the invention: SYSTEM FOR ROTATIONALLY LOCKING A BLADE OF A FAN MODULE BY AN INSERT

[0001] The present invention relates to a system for locking in rotation a blade of a fan module by an insert. The invention finds a particularly advantageous, but not exclusive, application with a fan rotor module used with a test machine.

[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] A test machine for a test bench, for example a fan of an aerodynamic demonstrator, has only a single air flow and is devoid of a low-pressure compressor, a high-pressure compressor and 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 test machine 1. 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 test machine 1.

[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 machine, 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, and - a rotation locking system for the blade comprising: - a split insert having a conical external face and an opening in which the blade root is arranged, - a platform provided with a passage hole into which the split insert is inserted, said passage hole being delimited by an internal face having a conical shape of a shape complementary to the external face of the split insert, and - at least one fixing member capable of fixing the platform on the annular hub, so that tightening of the fixing member ensures compression of the split insert between the platform and the blade root so as to lock the blade in a 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 also makes it possible to test several different sets of blades with a reduced assembly and disassembly time compared to existing systems. The invention allows the adjustment of the blade setting 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 split insert comprises a slot extending along an entire height of the split insert.

[0010] According to one embodiment of the invention, the split insert comprises a circumferential groove made in the internal face delimiting the opening, said groove being intended to receive a rib made on the blade root.

[0011] According to one embodiment of the invention, the fixing member extends in a direction parallel to an axis of the blade root.

[0012] According to one embodiment of the invention, the fixing member is a screw inserted inside a fixing hole made in the platform and a tapped hole made in the annular hub.

[0013] According to one embodiment of the invention, the screw comprises a head arranged inside a bore provided in the platform so as not to disturb an aerodynamic flow of a vein of the test machine.

[0014] According to one embodiment of the invention, the split insert comprises a cylindrical base intended to be arranged inside the blade root housing.

[0015] According to one embodiment of the invention, the annular hub is a single-piece hub.

[0016] According to one embodiment of the invention, the module is a rotor module.

[0017] The invention also relates to a test machine for a turbomachine test bench comprising a module as previously defined.

[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 by way of illustration 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 schematic view in longitudinal section of a test machine with which the invention is implemented;

[0020] [Fig.2] [Fig.2] is a perspective view of a rotor module for a machine test according to the present invention;

[0021] [Fig.3] [Fig.3] is a partial perspective and sectional view of a system of rotational locking of a blade of a fan module according to the present invention;

[0022] [Fig.4] [Fig.4] is a sectional view of a rotational locking system of a blade of a fan module according to the present invention;

[0023] [Fig.5] [Fig.5] is a detailed perspective view of an insert belonging to a rotational locking system for a blade of a fan module according to the invention.

[0024] 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.

[0025] [Fig.2] shows a rotor module 4 for an aircraft turbomachine test machine comprising an annular hub 10 having an axis XI and a plurality of blades 11.

[0026] The annular hub 10 of the monobloc type comprises a plurality of blade root housings 12. Alternatively, the annular hub 10 can be formed by two coaxial annular elements fixed to each other and defining between them the blade root housings 12.

[0027] The blades 11 extend radially projecting outwards from 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.

[0028] A rotation locking system 15 of the blade 11 is capable of taking an unlocked state allowing rotation of the blade 11 around an axis of rotation X2 corresponding to an axis of the blade root 13 and a locked state ensuring blocking of the blade 11 in a desired angular position of the blade 11 for a test.

[0029] As illustrated in Figures 3 and 4, the rotational locking system 15 of the blade 11 comprises a split insert 16 having an external face 17 of conical shape and an opening 18 in which the blade root 13 is arranged. An internal face of the split insert 16 delimiting the opening 18 has a cylindrical shape.

[0030] More precisely, as can be seen in [Fig. 5], the split insert 16 generally has an annular shape with a conical external face. The split insert 16 comprises a through slot 26 made in a thickness of the insert 16 and extending along an entire height of the split insert 16. The height of the split insert 16 extends along an axis X3 of the insert 16.

[0031] The split insert 16 comprises a base 27 of cylindrical shape intended to be arranged inside the blade root housing 12. A portion of the split insert 16 comprising the conical external face 17 is located in an extension of the base 27.

[0032] The split insert 16 may comprise a circumferential groove 28 made in the internal face delimiting the opening 18. The groove 28 is intended to receive a rib 29 of corresponding shape made on the blade root 13, as shown in [Fig. 4]. The groove 28 may extend along an entire circumference of the split insert 16 or only a portion of a circumference of the split insert 16. Such a configuration makes it possible to improve radial retention of the blade 11 relative to the axis XI during rotation of the rotor module 4.

[0033] Furthermore, a platform 21 visible in figures 3 and 4, is provided with a passage hole 22 in which the split insert 16 is inserted. The platform 21 is constituted by a plate in the form of a portion of a cylinder of axis XL. The platform comprises an internal face pressed against an external face 17 of the hub 10. The internal face of the platform 21 has a radius of curvature corresponding to the radius of curvature of the external face 17 of the hub 10.

[0034] The passage hole 22 is delimited by an internal face having a conical shape of complementary shape to the external face 17 of the split insert 16. The passage hole 22 is a hole passing through the thickness of the platform 21.

[0035] As illustrated in [Fig.4], at least one fixing member 25, in in the occurrence two fixing members 25, are capable of fixing the platform 21 on the annular hub 10. A fixing member 25 extends in a direction parallel to an axis X2 of the blade root 13.

[0036] Preferably, a fixing member 25 is a screw inserted inside a fixing hole 32 made in the platform 21 and a tapped hole 33 made in the annular hub 10. The screw 25 has a head 34 arranged inside a bore 35 of corresponding shape provided in the platform 21 so as not to disturb an aerodynamic flow of a vein of the test machine. Alternatively, the fixing member 25 may take the form of a stud intended to cooperate with a nut arranged on the side of an internal face of the hub 10 or any other fixing member suitable for the application.

[0037] The platforms 21 associated with each blade root 13 are arranged edge to edge so as to delimit the shape of a cylinder arranged around the annular hub 10.

[0038] The operation of the rotational locking system 15 of a blade according to the invention is described below.

[0039] The split insert 16 is arranged inside the through hole 22 of the platform 21. The blade root 13 is arranged inside the through opening 18. The blade 11 is rotated around the axis X2 so as to choose a desired angular position.

[0040] When the angular positioning of the blade 11 is correct, tightening of the fixing members 25 ensures compression of the split insert 16 between the platform 21 and the blade root 13 so as to lock the blade 11 in a desired angular position. It is then possible to carry out tests of the fan according to this configuration of the rotor module.

[0041] In order to modify the angular position of the blade 11, the fixing members 25 are loosened, which releases rotation of the blade 11 around the axis of rotation X2.

[0042] The operations of handling the blade 11 and of tightening and loosening the fixing members 25 can be carried out by a human operator or automatically by a robot.

[0043] The invention thus makes it possible to quickly modify the setting of the blades 11 between two tests. The invention makes it possible to limit downtimes during a test as much as possible.

[0044] The invention further makes it possible to test several different sets of blades with reduced assembly and disassembly time compared to existing systems.

[0045] The invention allows the adjustment of the timing of the blade 11 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.

[0046] The invention respects the aerodynamic profile of the vein whatever the position of the blade, vibrations, or its internal movements due to pumping phenomena or transient flows during a change of timing.

[0047] The invention further guarantees mechanical strength of the parts and the assembly at all operating speeds of the turbomachine.

[0048] The invention also has the advantage of being a simple solution to implement containing a minimum of parts.

[0049] Alternatively, the blower module may be a stator module.

[0050] 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.

[0051] 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 (4), in particular for a test machine, 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), characterized in that said module (4) comprises a locking system (15) in rotation of the blade (11) comprising: - a split insert (16) having an external face (17) of conical shape and an opening (18) in which the blade root (13) is arranged, - a platform (21) provided with a passage hole (22) in which the split insert (16) is inserted, said passage hole (22) being delimited by an internal face having a conical shape of shape complementary to the external face (17) of the split insert (16), and - at least one member fixing (25) capable of fixing the platform (21) on the annular hub (10),so that tightening of the fixing member (25) ensures compression of the split insert (16) between the platform (21) and the blade root (13) so as to lock the blade (11) in a desired angular position.,

2. Module according to claim 1, characterized in that the split insert (16) comprises a slot (26) extending along an entire height of the split insert (16).

3. Module according to claim 1 or 2, characterized in that the split insert (16) comprises a circumferential groove (28) made in the internal face delimiting the opening (18), said groove (28) being intended to receive a rib (29) made on the blade root (13).

4. Module according to any one of claims 1 to 3, characterized in that the fixing member (25) extends in a direction parallel to an axis (X2) of the blade root (13).

5. Module according to any one of claims 1 to 4, characterized in that the fixing member (25) is a screw inserted inside a fixing hole (32) made in the platform (21) and a tapped hole (33) made in the annular hub (10).

6. Module according to claim 5, characterized in that the screw (25) comprises a head (34) arranged inside a bore (35) provided in the platform (21) so as not to disturb an air flow. dynamics of a vein of the test machine.

7. Module according to any one of claims 1 to 6, characterized in that the split insert (16) comprises a base (27) of cylindrical shape intended to be arranged inside the blade root housing (12).

8. Module according to any one of claims 1 to 7, characterized in that the annular hub (10) is a single-piece hub.

9. Module according to any one of claims 1 to 8, characterized in that the module is a rotor module.

10. Test machine for a turbomachine test bench comprising a module defined according to any one of the preceding claims.

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