Tool for protecting a turbine engine part

Abstract

The invention relates to a tool (50) for protecting a turbine engine part (26), the tool being generally ring-shaped, split so as to have two free circumferential ends (54), and comprising: - a first, radially outer protective portion (60); - a second, radially inner protective portion (62); - an intermediate protective portion (64) connecting the portions (60, 62), and defining a cavity (66) that is intended to accommodate a portion (40) of the part to be protected, projecting radially inward, wherein the tool is configured to be brought from an unjoined nominal configuration to an unjoined loaded configuration obtained via elastic deformation of the tool, through the application of a load (56) to the tool so as to decrease the radial extent thereof, and wherein the tool is also configured to be brought from the unjoined loaded configuration to a configuration in which it is joined to the part to be protected (26) via the release of the load (56).

Description

[0001] DESCRIPTION

[0002] TITLE: TOOL FOR PROTECTING A TURBOMACHINE PART

[0003] Technical field

[0004] The invention relates to the field of turbomachines, preferably aircraft turbomachines, and more specifically to the field of tools for protecting turbomachine parts. Such tools are intended to be arranged on the turbomachine parts to be protected, during the assembly and disassembly of these parts, and / or during their handling, for example during their maintenance.

[0005] The invention finds applications for parts of any type of turbomachine, such as aircraft turbojets or turboprops.

[0006] State of the prior art

[0007] Some turbomachine parts may have portions subject to risks of damage, for example during their disassembly, prior to maintenance operations.

[0008] For example, some parts include mounting flanges assembled within the turbomachine using an annular ring of bolts. To disassemble the part, the bolts must first be loosened and then disassembled. Loosening may require the application of high torque, which may cause a sudden jolt with the loosening tool. This tool may then come into contact with the part to be disassembled, and generate defects such as scratches, dents, or similar marks, which may cause the part to be non-compliant. Similar risks exist during assembly of the part, or during its handling, during its maintenance.

[0009] To date, few protective solutions have been deployed in maintenance workshops. Some solutions provide protection for parts with hook-and-loop fasteners, allowing the protection to be held in place around the part.

[0010] However, implementing this type of solution can be time-consuming. Moreover, it sometimes remains impossible, especially when the part is still mounted within the turbomachine, and there is no accessibility around this part. Description of the invention

[0011] To address at least partially the drawbacks mentioned above, the invention firstly relates to a tool for protecting a turbomachine part, the tool being configured to be arranged on the part at least during one step among a step of mounting the part within the turbomachine, a step of dismantling this part, and a step of handling the part, the tool being of generally annular shape, split so as to have two free circumferential ends, and comprising, in half-cross section:

[0012] - a first radially external protection part;

[0013] - a second radially internal protection part;

[0014] - an intermediate protective part connecting the first and second parts, and defining a housing intended to receive a portion of said part to be protected, projecting radially inwards, the tooling being configured to be brought from a nominal unassembled configuration, to a constrained unassembled configuration obtained by elastic deformation of the tooling, via the application of a constraint on the tooling so as to reduce its radial extent, and the tooling also being configured to be brought from the constrained unassembled configuration to a configuration assembled on the part to be protected, by releasing said constraint.

[0015] The invention is advantageous in that it allows for reliable and easy mounting of the protective tooling on the part to be protected. In addition, its design allows it to be mounted on certain parts even when these are still assembled within the turbomachine, and no protective device can be arranged, due to lack of accessibility around these parts. By offering the possibility of installing the protective tooling early in the part maintenance process, the risks of damage and non-conformity of this part are advantageously reduced.

[0016] The invention preferably provides at least one of the following optional technical features, implemented in isolation or in combination. Preferably, the protective tooling is self-supporting, in the sense that its holding in place on the part to be protected is ensured by its own shape. This avoids the use of self-gripping fasteners, and allows rapid assembly of the tooling on the part, which is preferably carried out manually.

[0017] Preferably, in the nominal unassembled configuration, the intermediate protective part has, on the side of the second radially internal protective part, a junction wall curved radially outwards, and extending radially outwards beyond an internal radial bottom of the housing defined by this intermediate protective part, and / or in the nominal unassembled configuration, the second radially internal protective part extends radially inwards beyond the intermediate protective part.

[0018] Preferably, each of the first and second protective parts comprises a thickened support zone. Each support zone therefore constitutes a preferred support zone on the part to be protected, so that a clearance may remain between the part and the other parts of the tool, close to these support zones. This clearance makes it possible to adapt to slight differences in shape and / or dimensions, likely to be encountered on parts of the same reference.

[0019] Preferably, each of the two free circumferential ends comprises a gripping member, preferably an orifice, so as to facilitate manual gripping by an operator, or using a tool for stressing the protective tooling.

[0020] The invention also relates to an assembly comprising a turbomachine part, as well as a protective tool as described above, intended to protect said part at least during one step among a step of mounting the part within the turbomachine, a step of dismantling this part, and a step of handling the part.

[0021] Preferably, the turbomachine part is a connecting part between a turbine rotor and a turbomachine shaft, the connecting part comprising:

[0022] - a mounting flange on the turbine rotor, the flange having mounting holes intended to be passed through by mounting members; - a generally conical portion extending radially inward from a radially inner end of the mounting flange; and

[0023] - at a junction zone between the fixing flange and the generally conical part, a portion of said part to be protected, the portion to be protected projecting radially inwards, and preferably also in a longitudinal direction. Preferably, the projecting portion to be protected corresponds to a mechanical reinforcement zone of the part, possibly equipped with a balancing system.

[0024] The invention also relates to a method of assembling such protective tooling on a turbomachine part, comprising the following steps:

[0025] - transition of the tooling from its nominal unassembled configuration to its constrained unassembled configuration obtained by elastic deformation of the tooling, via the application of the constraint on this tooling so as to reduce its radial extent;

[0026] - passage of the tool from its unassembled constrained configuration to its assembled configuration on the part to be protected, by releasing said constraint, passage during which a projecting portion to be protected of said part is inserted into the housing defined by the intermediate protective part of the tool.

[0027] Finally, the invention also relates to a method for maintaining a turbomachine part, comprising the following steps: a) a step of dismantling this part; b) a step of handling the part, from the turbomachine to a maintenance station; c) a step of maintaining the part; d) a step of handling the part to the turbomachine; e) a step of mounting the part on the turbomachine; and also comprising the implementation of the method of assembling a protective tool as described above, on said turbomachine part, before the implementation of any step among steps a) to e), the method also comprising a disassembly of the protective tool, after the implementation of said any step, or one of the steps a) to e) which follow it.In this regard, it is noted that the assembly of the protective tooling is preferably carried out before the step of dismantling this part, and that this tooling is preferably kept on the part at least during part of the step of handling the part, from the turbomachine to the maintenance station. In addition, it is noted that the cycle of assembly and disassembly of the tooling can be repeated during the same maintenance process of the part, without departing from the scope of the invention. In addition, it is noted that the protective tooling could be installed even before the dismantling of the part, as early as possible in the procedure, and in particular in the modular state, even if the maintenance process does not provide for dismantling of the part to be protected. For example, the installation of the tooling can be carried out before the loosening of the bolts of the cone connection.

[0028] Additionally, this protective tooling could also be installed for inspection in the modular state, without implementing the maintenance process for disassembling the cone. For example, if during maintenance the disc must be disassembled, but the cone must remain assembled, it may be advisable to protect the area during the inspection of the low-pressure turbine, without disassembling the cone.

[0029] Other advantages and characteristics of the invention will appear in the detailed non-limiting description below.

[0030] Brief description of the drawings

[0031] The following detailed description refers to the attached figures in which:

[0032] [Fig. 1] is a schematic longitudinal sectional view of an aircraft turbomachine;

[0033] [Fig. 2] is a more detailed view, in longitudinal half-section, of a part of a turbine of the turbomachine shown in the preceding figure;

[0034] [Fig. 3] is a more detailed view, in longitudinal half-section, of a part of the turbine shown in the preceding figure, showing in particular a part of the turbine to be protected;

[0035] [Fig. 4] is a perspective view of a portion of the turbine part shown in the preceding figure, equipped with protective tooling so as to form an assembly according to a preferred embodiment of the invention; [Fig. 5] is a partial view, in longitudinal half-section, of the assembly shown in the preceding figure;

[0036] [Fig. 6] is a front view of the protective tooling, in a nominal unassembled configuration, and in a constrained unassembled configuration obtained by elastic deformation of this tooling;

[0037] [Fig. 7] is a partial view, in longitudinal half-section, of the protection tooling according to another preferred embodiment of the invention;

[0038] [Fig. 8],

[0039] [Fig. 9] are views showing the protection tooling in different configurations, during a process of assembling this tooling on the turbine part.

[0040] Detailed description of embodiments

[0041] Referring firstly to Figure 1, an aircraft turbomachine 1 is shown. This is a double-flow, double-spool turbojet engine. However, it could be a turbomachine of another type, for example a single-spool turbojet engine, or even a turboprop, without departing from the scope of the invention.

[0042] The turbomachine 1 has an axis 2 around which its various components extend, this axis being called the longitudinal central axis of the turbomachine. Subsequently, the terms “upstream” and “downstream” are defined relative to a general direction 5 of flow of the gases through the propulsion unit 1 when the latter generates direct thrust, this direction being parallel or substantially parallel to the axis 2. These terms “upstream” and “downstream” could respectively be substituted by the terms “front” and “rear”, with the same meaning. In addition, the turbomachine 1 is represented in a frame of reference formed by three mutually orthogonal directions, namely the longitudinal direction L parallel to the axis 2, the circumferential direction C, and the radial direction R.

[0043] The turbomachine 1 comprises, from upstream to downstream along the main gas flow direction 5, a fan 3, a low-pressure compressor 4, a high-pressure compressor 6, a combustion chamber 11, a high-pressure turbine 7 and a low-pressure turbine 8. Conventionally, after passing through the fan, the air divides into a central primary flow 12a and a secondary flow 12b which surrounds the primary flow. The primary flow 12a flows in a main gas circulation vein 14a passing through the compressors 4, 6, the combustion chamber 11 and the turbines 7, 8. The secondary flow 12b flows in a secondary vein 14b delimited radially outwards by a motor casing, surrounded by a nacelle 9.

[0044] Figure 2 shows a part of one of the two aforementioned turbines 7, 8, preferably the low-pressure turbine 8 located at the rear of the turbomachine. Conventionally, the turbine comprises several turbine stages, each formed by the association of a stator assembly 20, called the turbine distributor, and a moving wheel 22 equipped with an annular ring of moving blades. The moving wheels 22 are connected to each other to form a rotor 23 of the turbine. This rotor is coupled in rotation to a turbomachine shaft 24, here the low-pressure engine shaft, centered on the axis 2 and possibly made of several parts connected to each other. To achieve this coupling, a connecting piece 26 is implemented, a radially external end of which is fixed to the turbine rotor 23, and a radially internal end of which is fixed to the shaft 24, for example at a junction 28 between two sections of this shaft.This fixing can be achieved by an annular crown of bolts 29. The connecting part 26 is also called “cone-trunnion”, due to its shape.

[0045] More specifically with reference to figures 2 to 4, the connecting piece 26 comprises several parts, described below, integral with each other.

[0046] First of all, this part 26 is annular, centered on the axis 2, and it comprises a flange 30 for fixing to the turbine rotor 23. This flange 30, preferably of radial or substantially radial orientation, has mounting holes 32 crossed by mounting members 33, of the bolt type forming an annular crown of mounting members. The flange 30 can be scalloped, as shown in FIG. 4.

[0047] From a radially internal end of the fixing flange 30, the connecting piece 26 comprises a part 34 of generally conical shape, centered on the axis 2 while opening axially downstream. The conical part 34 and the fixing flange 30 are preferably made in one piece.

[0048] The connecting part 26 also comprises, at a junction zone between the flange 30 and the conical part 34, a portion 40 to be protected, which projects radially inwards, and also in the longitudinal direction L, downstream.

[0049] The projecting portion to be protected 40 corresponds to a mechanical reinforcement zone 42 of the part 26, possibly equipped with a balancing system 44. This may for example be in the form of a mass balancing bead attached radially inwards to the reinforcement zone 42, formed by an excess thickness of material, in particular an axial excess thickness towards the downstream side. The projecting portion to be protected 40 is annular in shape, centered on the axis 2, and also called a “dropper” because of its shape, even if it is not normally intended to perform such a function. In a half-section like that shown in FIG. 3, the projecting portion 40 takes for example the shape of a lug.

[0050] The projecting portion 40 therefore forms an annular appendage on the connecting part 26, which must be protected in different circumstances. In particular, it is a matter of protecting it during at least one step among a step of mounting the part 26 on the turbomachine, a step of dismantling this part, or even a step of handling / inspection of the part, during its maintenance or its initial assembly within the turbomachine. This protection can also be useful during the assembly or inspection of the low-pressure turbine.

[0051] To do this, a protective tool 50 is provided, forming with the part 26 an assembly 52 specific to the present invention.

[0052] With reference to figures 4 to 6, the protection tool 50 has a generally annular shape, centered on the axis 2, and split so as to have two free circumferential ends 54, visible in figure 6. These two ends 54 are preferably spaced from each other in the circumferential direction C. The tool 50, in the general shape of a split or split ring, is preferably produced by additive manufacturing, and it has a certain elasticity, required for its placement on the part 26 to be protected. Indeed, the protection tool 50 can not only adopt a nominal unassembled configuration, corresponding to the largest representation in figure 6, but also a constrained unassembled configuration, corresponding to the smallest representation in this same figure 6.The transition from one to the other of the two configurations is obtained by elastic deformation of the tool 50, via the application of a stress 56 on this protective tool. This stress 56, shown diagrammatically in FIG. 6, is preferably carried out manually by an operator, by exerting circumferential forces on the two free ends 54 aimed at bringing these two ends closer to each other. To facilitate implementation, each of the two free circumferential ends 54 comprises a gripping member, such as an orifice 58, easy to grip by an operator wishing to manually apply the stress 56.

[0053] The elastic deformation caused in this way allows the tool 50 to retain a generally annular shape, but with a reduced radial extent Er, allowing it to be positioned relative to the part 26, before assembly, as will be described below. The protective tool 50 thus functions in the manner of a circlip.

[0054] The protective tool 50 has a half-cross section of constant, or substantially constant, shape and dimensions. By half-cross section, it is meant a half-section of the tool of generally annular shape, locally in a section plane orthogonal to the circumferential direction C, in relation to the axis 2.

[0055] In each half-cross section, a first radially external protective part 60 is thus provided, intended to cover axially downstream at least a lower part of the flange 30 of the part. In the assembled state of the tooling shown in FIG. 5, the first protective part 60 and the flange 30 preferably have the same orientation, or substantially the same orientation.

[0056] Opposite in the radial direction R, the protection tool 50 comprises a second radially internal protection part 62, intended to cover downstream at least an upper part of the conical part 34 of the part 26. In the assembled state, the second protection part 62 and the conical part 34 which it covers, preferably have the same orientation, or substantially the same orientation, both being of complementary conical general shapes.

[0057] To connect these two parts 60, 62, the tool 50 comprises an intermediate protective part 64, which defines a housing 66 intended to receive the projecting portion 40 to be protected. The housing 66 thus turns out to be open axially / longitudinally upstream, and radially outwards. This housing 66 then has a downstream axial bottom 68, as well as an internal radial bottom 70. In the assembled state, the projecting portion 40 occupies the housing 66 of the tool, these two elements having complementary, or substantially complementary, shapes.

[0058] It is noted that the three aforementioned parts 60, 62, 64 are in reality annular, centered on the axis 2, with identical or substantially identical thicknesses.

[0059] The intermediate protective portion 64 has, on the side of the second protective portion 62, a junction wall 72 curved radially outwards. This wall 72 delimits a part of the housing 66, but it also serves to protect the connecting radius 74 between the conical portion 34, and the projecting portion 40 of the part to be protected. Here too, the junction wall 72 and the connecting radius 74 are of complementary shapes. Still in the nominal unassembled configuration, the curved junction wall 72 extends in the radial direction R outwards beyond the internal radial bottom 70 of the housing 66, which in particular makes it possible to form this housing. In addition, still in this nominal unassembled configuration, the second protective portion 62 extends radially inwards beyond the intermediate protective portion 64.

[0060] Finally, the intermediate protective portion 64 has, on the side of the first protective portion 60, a junction wall 76 extending radially outward and axially / longitudinally upstream. This wall 76 delimits a portion of the housing 66, but it also serves to protect the connecting radius 78 between the flange 30, and the projecting portion 40 of the part to be protected 26. The junction wall 76 and the connecting radius 78 also have complementary shapes. According to another preferred embodiment shown in FIG. 7, each of the first and second protective portions 60, 62 comprises a thickened support zone 80, for example between 0.1 mm and 0.5 mm, and preferably of the order of 0.2 mm.

[0061] Each support zone 80 then corresponds to the zone intended to be in contact with the corresponding part 30, 34 of the part to be protected 26. Each thickened support zone 80 results in the presence of an adjacent recess, making it possible to provide clearance between the part 26 and its protection tool 50. This makes it possible to accommodate slight differences in shape and / or dimensions, likely to be encountered on connection parts 26 of different turbomachines. These two support zones 80 are preferably located at the periphery of the protection parts 60, 62, respectively.

[0062] Whatever the preferred embodiment envisaged, the protection tool 50 is self-supporting after having been assembled on the part to be protected 26, since its holding in place on this part is ensured by its own shape, and more precisely by its shape cooperation with this part 26.

[0063] Figures 8 and 9 diagram a method of assembling the protective tooling 50, on the connecting part 26 of the turbine. This method firstly comprises a step consisting of moving the tooling 50 from its nominal unassembled configuration shown in Figure 8, to its constrained unassembled configuration shown in dotted lines in Figure 9. This step is similar to the operation described above with reference to Figure 6, aimed at reducing the size of the tooling 50 in the radial direction R, by elastically deforming it, preferably manually by pulling on its ends 54. The resulting reduction in diameter allows in particular the axial introduction upstream of the tooling 50, until it is in its final axial position relative to the part to be protected 26, or close to this position.Indeed, to achieve the desired axial position, the reduction in radial size is carried out so that the curved junction wall 72 has a smaller maximum outside diameter than the minimum inside diameter of the projecting portion 40 to be protected. This facilitates the axial insertion upstream of the tool 50, in the conical part 34 of the part 26. This axial insertion may also locally require the axial deformation of the intermediate protection part 64, near the curved junction wall 76, stressed by the support of the projecting portion 40, as has been shown diagrammatically in FIG. 9.

[0064] Then, the method is continued by passing the tool 50 from its unassembled constrained configuration shown in dotted lines in Figure 9, to its assembled configuration on the connecting part 26, shown in solid lines in this same Figure 9. Such a passage is easily achieved by progressively releasing the constraint which was applied to maintain the tool 50 in the unassembled constrained configuration. During this stress release, the operator is led to guide the tool which redeploys radially, with the consequence of the progressive insertion of the projecting portion 40 into the housing 66 of this tool.

[0065] In the assembled configuration, the tool 50 may still exhibit elastic deformation, in the sense that it does not exactly return to its aforementioned nominal configuration. This makes it possible to further improve the self-supporting nature of the protective tool.

[0066] This assembly of the tooling on the part can be carried out during a maintenance process of the connecting part 26, which requires its extraction from the turbomachine, before undergoing a maintenance step such as an inspection, a repair, etc.

[0067] In order to limit the risks of damage to the part 26 to be removed from the turbomachine, the assembly of the tool 50 is carried out as soon as possible, as soon as this part 26 becomes accessible from downstream.

[0068] Then, the following steps are implemented: a) a step of dismantling this part 26, requiring the removal of the bolt crowns 29 and 33. The installed tooling makes it possible in particular to protect the projecting portion 40 of the part, when loosening the nuts 33 from downstream, which can cause jolts with the bolt loosening tool; b) a step of handling the part 26, consisting of transporting it from the turbomachine to a maintenance station; c) a step of maintaining the part 26, of the type mentioned above. Before this maintenance step, the tooling 50 can be removed, to facilitate this maintenance step; d) a step of handling the part 26 towards the turbomachine.Before this step, the tooling 50 can be reassembled on this part if it was removed from it in a previous step, in order to limit the risks of damage to the part; and e) a step of mounting the part on the turbomachine, also called a reassembly step, at the end of which the tooling 50 can be disassembled. This disassembly is carried out generally by carrying out the same steps as those allowing the assembly of this tooling, but in a reverse order, always preferably manually.

[0069] As mentioned previously, the protection tooling can also be set up in a modular state, and for simple inspection of the low pressure turbine, even if no direct action is planned on the part to be protected.

[0070] Various modifications may be made by those skilled in the art to the invention which has just been described, solely by way of non-limiting examples, and the scope of which is defined by the appended claims.

Claims

CLAIMS 1. Tooling (50) for protecting a part (26) of a turbomachine, the tooling being configured to be arranged on the part at least during one step among a step of mounting the part within the turbomachine, a step of dismantling this part, and a step of handling the part, the tooling being of generally annular shape, split so as to have two free circumferential ends (54), and comprising, in half-cross section: - a first radially external protection part (60); - a second radially internal protection part (62); - an intermediate protective portion (64) connecting the first and second portions (60, 62), and defining a housing (66) intended to receive a portion (40) of said part to be protected, projecting radially inwards, the tooling being configured to be brought from a nominal unassembled configuration, to a constrained unassembled configuration obtained by elastic deformation of the tooling, via the application of a constraint (56) on the tooling so as to reduce its radial extent, and the tooling also being configured to be brought from the constrained unassembled configuration to a configuration assembled on the part to be protected (26), by releasing said constraint (56).

2. Protective tool according to claim 1, characterized in that it is self-supporting.

3. Protective tooling according to claim 1 or 2, characterized in that in the nominal unassembled configuration, the intermediate protective part (64) has, on the side of the second radially internal protective part (62), a junction wall (72) curved radially outwards, and extending radially outwards beyond an internal radial bottom (70) of the housing (66) defined by this intermediate protective part (64), and / or in that in the nominal unassembled configuration, the second radially internal protective part (62) extends radially inwards beyond the intermediate protective part (64).

4. Protective tool according to any one of the preceding claims, characterized in that each of the first and second protective parts (62, 64) comprises a thickened support zone (80).

5. Protective tool according to any one of the preceding claims, characterized in that each of the two free circumferential ends (54) comprises a gripping member (58), preferably an orifice.

6. Assembly (52) comprising a turbomachine part (26), as well as a protective tool (50) according to any one of the preceding claims, intended to protect said part (26) at least during one step among a step of mounting the part within the turbomachine, a step of dismantling this part, and a step of handling the part.

7. Assembly according to claim 6, characterized in that the turbomachine part (26) is a connecting part between a turbine rotor (23) and a turbomachine shaft (24), the connecting part (26) comprising: - a fixing flange (30) on the turbine rotor (23), the flange having mounting holes (32) intended to be passed through by mounting members (33); - a generally conical portion (34) extending radially inward from a radially inner end of the fixing flange (30); and - at a junction zone between the fixing flange (30) and the generally conical part (34), a portion (40) of said part to be protected, the portion to be protected projecting radially inwards, and preferably also in a longitudinal direction.

8. Assembly according to claim 7, characterized in that the projecting portion to be protected (40) corresponds to a mechanical reinforcement zone (42) of the part, possibly equipped with a balancing system (44).

9. Method for assembling a protective tool (50) according to any one of the preceding claims, on a turbomachine part (26), comprising the following steps: - passage of the tool (50) from its nominal unassembled configuration to its constrained unassembled configuration obtained by elastic deformation of the tool, via the application of the constraint (56) on this tool so as to reduce its radial extent; - passage of the tool (50) from its unassembled constrained configuration to its assembled configuration on the part to be protected (26), by releasing said constraint (56), passage during which a projecting portion to be protected (40) of said part (26) is inserted into the housing (66) defined by the intermediate protection part (64) of the tool.

10. A method of maintaining a turbomachine part (26), comprising the following steps: a) a step of dismantling this part (26); b) a step of handling the part (26), from the turbomachine (1) to a maintenance station; c) a step of maintaining the part (26); d) a step of handling the part (26) to the turbomachine (1); e) a step of mounting the part (26) on the turbomachine (1); and also comprising implementing the method of assembling a protective tool (50) according to the preceding claim, on said turbomachine part (26), before implementing any step among steps a) to e), the method also comprising disassembling the tool (50), after implementing said any step or one of the steps a) to e) which follow it.

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