Patent Application
20220220866
The present invention relates in particular to a tool for removing a fan disc alone from a module and to a method for removing a fan disc alone from a module by means of such a tool.
A turbomachine, such as a turbofan engine, comprises, from upstream to downstream in the direction of gas flow, a fan, one or more compressor stages (low pressure then high pressure), a combustion chamber, one or more turbine stages (high pressure then low pressure) and an exhaust nozzle.
Such a turbomachine corresponds to the assembly of a plurality of modules mounted in relation to each other. During a maintenance operation, various modules are dismounted and transported to different stations in order to undergo various maintenance operations (replacement of the wearing parts, replacement/repair of defective parts, etc.) necessary to put the turbomachine back into service.
In the following, we will focus on the “low-pressure compressor module”, hereinafter referred to as “module”.
Such a module is defined along a longitudinal axis X and comprises a rotor and a stator which are independent of each other.
The rotor comprises in particular a fan disc, a drum and an annular sealing part centered on the axis X and secured to each other by a circular row of bolts each comprising a screw and a nut. Each screw also passes through a retaining member arranged inside the rotor. Each retaining member has at least two opposing lugs arranged around a head of the screw and projecting from it, this retaining member allowing to hold the head of the corresponding screw in place when the associated nut is removed, which is itself located outside the rotor. The rotor also comprises several annular rows of vanes fitted to the drum and arranged one behind the other, each row of vanes being more commonly referred to as an impeller.
The stator is centered on the axis X and surrounds the drum. The stator comprises several compressor stator vanes annular assemblies interposed between the impellers. The first assembly of compressor stator vanes is associated with the fan so as to form the stage n° 1, the following being each associated with an impeller so as to form the following stages. Each compressor stator vanes assembly comprises an inner shell and an outer shell connected to each other by an annular row of vanes. The outer shells of all the compressor stator vanes assemblies are flanged together.
The existing tools allow the entire module to be dismounted according to a determined method, whereby the fan disc is one of the elements of the module last removed. In other words, the removal of the fan disc cannot be done without a complete dismounting of the module.
There is an increasing demand for maintenance operations on the fan disc only, these maintenance operations requiring only the removal of the fan disc.
It is understood that the existing tools are not suitable in the case where it is necessary to remove only the fan disc. Indeed, as mentioned above, for such an operation, the operators are obliged to proceed to a complete dismounting of the module, to the detriment of the productivity.
The objective of the present invention is thus to propose, on the one hand, a tool for removing a fan disc alone from a module and, on the other hand, a method for removing a fan disc alone from a module by means of such a tool, thus allowing a gain in productivity.
The invention thus proposes a tool for removing a fan disc alone from a module having a longitudinal axis X of a turbomachine comprising a rotor and a stator, the rotor comprising the fan disc, a drum and an annular sealing part centered on the axis X and secured to one another via a circular row of bolts each comprising a screw and a nut, each screw passing through a retaining member arranged inside the rotor, each retaining member having at least two opposing lugs arranged around a head of the screw and projecting with respect to the head, the stator being centered on the axis X and surrounding the drum, the stator being longitudinally delimited by a compressor stator vanes assembly arranged opposite the fan disc, the compressor stator vanes assembly comprising an outer shell having a flange, the tool having a vertical axis Z comprising:
a frame comprising ground support means;
an annular plate centered on the axis Z and secured to the frame, this plate comprising first and second circular rows of pins as well as two holes arranged around the axis Z at a regular pitch, each of the two holes being arranged between the first and second rows, each of the pins being configured to bear the head of a screw so as not to damage the lugs of the retaining members, each hole being configured to receive an indexing finger of the module relative to the tool;
at least three supports distributed in a regular manner around the axis Z and secured to the frame, each support comprising a bearing surface, the bearing surfaces being coplanar and being configured to support the flange of the compressor stator vanes assembly of the module, the three supports being vertically located below the plate;
a first visual marker arranged on the frame and configured to angularly orient the module relative to the tool.
Such a tool allows the removal of the fan disc alone while keeping the rest of the module assembled. Thus, during a maintenance operation involving only the fan disc, such a tool allows a significant gain in productivity.
In addition, such a tool allows the removal of the fan disc alone without damaging other components of the module, in particular the retaining members and the screws.
Such a tool can also be used to re-install the repaired fan disc (or to install a new fan disc) on the rest of the assembled module.
The tool according to the invention may comprise one or more of the following characteristics and/or steps, taken alone or in combination with each other:
the first visual marker is a vertical line;
the tool comprises a second visual marker arranged on the frame and configured to determine a vertical position of the module from which the module is to be indexed relative to the tool;
the second visual marker is a horizontal line;
each of the three supports comprises a recess configured to allow the passage of an annular row of vanes fitted to the drum.
The present invention also relates to a method for removing a fan disc alone from a module having a longitudinal axis X of a turbomachine comprising a rotor and a stator, the rotor comprising the fan disc, a drum and an annular sealing part centered on the axis X and secured to one another via a circular row of bolts each comprising a screw and a nut, each screw passing through a retaining member arranged inside the rotor, each retaining member having at least two opposing lugs arranged about a head of the screw and projecting with respect to the head, the stator being centered on the axis X and surrounding the drum, the stator being longitudinally delimited by a compressor stator vanes assembly arranged opposite the fan disc, the compressor stator vanes assembly comprising an outer shell having a flange, by means of the tool as previously described, the method comprising chronologically the steps of:
a) removing two predetermined bolts hereinafter referred to as reference bolts so as to have two free orifices at the level of the rotor, the angular distance between the reference bolts being equal to the angular distance between the two holes of the plate;
b) positioning the module above the tool in a vertical position so that the longitudinal axis X of the module is substantially vertical and substantially coaxial with the vertical axis Z of the tool, the fan disc then being vertically above the drum;
c) aligning one of the free orifices with the first visual marker so as to angularly orient the module with respect to the tool;
d) indexing the module with respect to the tool by introducing two indexing fingers from the outside of the module, each indexing finger passing through a free orifice of the rotor and then through a hole of the plate;
e) abutting the heads of the screws on the pins of the plate, the drum then surrounding the plate;
f) abutting the flange of the compressor stator vanes assembly on the bearing surfaces of the three supports;
g) removing all the nuts from the bolts;
h) extracting in a controlled manner the fan disc alone via at least one extractor;
i) removing the fan disc alone.
Such a method allows the removal of the fan disc alone, by means of the tool, while keeping the rest of the module assembled. Thus, during a maintenance operation involving only the fan disc, the implementation of such a method allows a significant gain in productivity.
In addition, such a method allows the removal of the fan disc alone without damaging the other components of the module, in particular the retaining members and the screws.
The method according to the invention may comprise one or more of the following characteristics and/or steps, taken alone or in combination with each other:
the fan disc is extracted during the step h) via three extractors distributed in a regular manner around the axis Z, the extraction being controlled by progressively unscrewing three extraction nuts previously screwed onto three screws each located close to one of the three extractors, and by progressively inserting wedges around the three screws having the extraction nuts between the fan disc and the drum, the extraction nuts and the wedges being in a non-metallic material;
the step h) comprises the sub-steps of:
h1) arranging each extraction nut at a distance D from a upper face of a corresponding lobe of the fan disc, the upper face being arranged opposite the extraction nut;
h2) actuating the three extractors so that each upper face is in contact with the corresponding extraction nut;
h3) arranging one or more wedges having a total height H around each screw having an extraction nut between the fan disc and the drum, the total height H being equal to the distance D,
the step d) is carried out when the flange of the compressor stator vanes assembly is located vertically at the level of a second visual marker arranged on the frame of the tool;
the module is held during the steps a) to f) via a first handling tooling on which the module is positioned and held, the first handling tooling comprising at least one pair of opposing first trunnions, each of the first trunnions being linked to a bracket of a lifting system;
the first handling tooling is configured to allow the positioning of the rotor relative to the stator to be adjusted longitudinally over a predetermined range or vice versa;
the fan disc is held during the steps g) to i) via a second handling tooling on which the fan disc is positioned and held, the second handling tooling comprising at least one pair of opposing second trunnions, each of the second trunnions being linked to a bracket of a lifting system.
The invention will be better understood and other details, characteristics and advantages of the present invention will become clearer from the following description made by way of non-limiting example and with reference to the attached drawings, in which:
In the present application, the terms “inner” and “outer” associated with the various components of the module 1 are defined with respect to the longitudinal axis X.
More specifically, the rotor 2 comprises a fan disc 4, a drum 5 and an annular sealing part 6 centered on the axis X and secured to each other by a circular row of bolts 7 each comprising a screw 8 and a nut 9. Each screw 8 passes through a retaining member 10 arranged inside the rotor 2. Each retaining member 10 has at least two opposing lugs 11 arranged around a head 12 of the screw 8 and projecting from the head 12.
The stator 3 is centered on the axis X and surrounds the drum 5. The stator 3 is longitudinally delimited by a compressor stator vanes assembly r4 arranged opposite the fan disc 4, the compressor stator vanes assembly r4 comprising an outer shell 14 having a flange 15.
According to the embodiment illustrated in the figures and in particular in
As illustrated in
The sealing part 6 is also press-fitted on a projection 18 of the fan disc 4 at the level of its inner end and hooked onto a projection 19 of the drum 5 at the level of its outer end.
As illustrated in
According to the embodiment shown in the figures and in particular in
By convention, in the present application, the terms “upstream” and “downstream” are defined in relation to the direction of flow of the gases in the module 1, the gases passing successively through the different stages.
A module 1 in a third state E3 corresponds to a module 1 in a second state E2 from which the fan disc 4 has been removed.
The fan disc 4 alone is removed from a module 1 in a second state E2 by means of a tool 22.
According to the invention, the tool 22 is defined along a vertical axis Z and comprises:
a frame 23 comprising ground support means 24;
an annular plate 25 centered on the axis Z and secured to the frame 23, this plate 25 comprising first and second circular rows 26a, 26b of pins 27 as well as two holes 28 arranged around the axis Z at a regular pitch, each of the two holes 28 being arranged between the first and second rows 26a, 26b, each of the pins 27 being configured to bear the head 12 of a screw 8 so as not to damage the lugs 11 of the retaining members 10, each hole 28 being configured to receive an indexing finger 29 of the module 1 relative to the tool 22;
at least three supports 30 distributed in a regular manner around the axis Z and secured to the frame 23, each support 30 comprising a bearing surface 31, the bearing surfaces 31 being coplanar and being configured to support the flange 15 of the compressor stator vanes assembly r4 of the module 1, the three supports 30 being vertically located below the plate 25;
a first visual marker 32 arranged on the frame 23 and configured to angularly orient the module 1 with relative to the tool 22.
In the present application, the terms “lower” and “upper” associated with the various components of the tool 22 are defined with respect to the vertical axis Z. Further, in the present application, the terms “inner” and “outer” associated with the various components of the tool 22 are defined with respect to the vertical axis Z.
According to the embodiment illustrated in the figures and in particular in
The plate 25 comprises an annular upper surface 35 delimited by two rims 36, the rims 36 being configured to hold the ends of the sealing part 6 when the repaired fan disc (or a new fan disc) is press-fitted on a module 1 in a third state E3. The pins 27 of the first and second rows 26a, 26b are arranged on the upper surface 35. The first and second rows 26a, 26b have the same number of pins 27 (in this case ten pins) and are symmetrical with respect to the axis Z. The holes 28 are thus also symmetrical with respect to the axis Z. The pins 27 as well as the two holes 28 are arranged equidistant from the axis Z. The holes 28 are blind holes opening at the level of the upper surface 35. The angular distance between the two holes 28 is 180 degrees. The indexing fingers 29 have been shown in
The bearing surfaces 31 lie in a common plane perpendicular to the axis Z. Each bearing surface 31 is located at an upper end of the corresponding support 30. Each bearing surface 31 is in the form of an annular sector and is delimited on the outside by an edge 38. The three supports 30 are arranged in relation to the pins 27 in such a way that the heads 12 are supported before the flange 15 when the module 1 is positioned on the tool 22. Each support 30 comprises a recess 39 oriented on the side of the vertical axis Z and configured to allow the passage of the fifth assembly of compressor stator vanes R5, when the module 1 is positioned on the tool 22. The supports 30 may be adjustable relative to the platform 33 in a direction perpendicular to the axis Z.
The first visual marker 32 is in the form of a vertical line 32 arranged on the periphery of the barrel 34 and the periphery of the plate 25, said vertical line 32 being configured to angularly orient the module 1 relative to the tool 22. This first visual marker 32 may be obtained via the application of one or more self-adhesive strips.
The tool 22 comprises a second visual marker 40 in the form of a horizontal line 40 arranged on the periphery of the barrel 34, said horizontal line 40 being configured to determine a vertical position of the module 1 from which the module 1 is to be indexed relative to the tool 22. Here the horizontal line crosses the vertical line. In the same manner as the first visual marker 32, this second visual marker 40 may be obtained via the application of one or more self-adhesive strips.
Advantageously, the plate 25 and the supports 30 are made of a non-metallic material, so as not to damage the module 1. The plate 25 and the supports 30 are made of Teflon® for example.
The removal of a fan disc 4 alone from a module 1 in a second state E2 by means of the tool 22 is carried out according to a method comprising chronologically the steps of:
a) removing two predetermined bolts 7 hereinafter referred to as reference bolts so as to have two free orifices 41 at the level of the rotor 2, the angular distance between the reference bolts being equal to the angular distance between the two holes 28 of the plate 25; (
b) positioning the module 1 above the tool 22 in a vertical position so that the longitudinal axis X of the module 1 is substantially vertical and substantially coaxial with the vertical axis Z of the tool 22, the fan disc 4 then being vertically above the drum 5;
c) aligning one of the free orifices 41 with the first visual marker 32 so as to angularly orient the module 1 with respect to the tool 22; (
d) indexing the module 1 with respect to the tool 22 by introducing from the outside of the module 1 two indexing fingers 29, each indexing finger 29 passing through a free orifice 41 of the rotor 2 and then through a hole 28 of the plate 25; (
e) abutting the heads 12 of the screws 8 on the pins 27 of the plate 25, the drum 5 then surrounding the plate 25; (
f) abutting the flange 15 of the compressor stator vanes assembly r4 on the bearing surfaces 31 of the supports 30; (
g) removing all the nuts 9 from the bolts 7;
h) extracting in a controlled manner the fan disc 4 alone via at least one extractor 42; (
i) removing the fan disc 4 alone. (
As mentioned above, the method is implemented on a module 1 in a second state E2, and in other words a module 1 from which the fifth assembly of compressor stator vanes r5 has been removed.
The module 1 is held during the steps a) to f) via first handling tooling 43 on which the module 1 is positioned and held, the first handling tooling 43 comprising at least one pair of opposing first trunnions 44, 45, each of the first trunnions 44, 45 being linked to a bracket 46 of a lifting system 47.
According to the embodiment illustrated in the figures and in particular in
Advantageously, as illustrated in
As illustrated in
As illustrated in
As illustrated in
As shown in
As illustrated in
As illustrated in
The method comprises, between the steps f) and g), a step f1) of removing the first handling tooling 43 from the module 1.
The fan disc 4 is held during the steps g) to i) via a second handling tooling 51 on which the fan disc 4 is positioned and held, the second handling tooling 51 comprising at least one pair of opposing second trunnions 52, each of the second trunnions 52 being linked to a bracket 46 of a lifting system 47.
According to the embodiment illustrated in the figures and in particular in
As illustrated in
As illustrated in
The wedges 56 allow to prevent the fan disc 4 from inclining during a drop in hydraulic pressure at the level of the extractors 42.
Advantageously, the extraction nuts 55 and the wedges 56 are made of a non-metallic material, so as not to damage the screws 8. The extraction nuts 55 and the wedges 56 are made of Teflon®, for example.
As illustrated in
h1) arranging each extraction nut 55 at a distance D from a upper face 60 of a corresponding lobe 16 of the fan disc 4, the upper face 60 being arranged opposite the extraction nut 55; (
h2) actuating the three extractors 42 so that each upper face 60 is in contact with the corresponding extraction nut 55; (
h3) arranging one or more wedges 56 having a total height H around each screw 8 having an extraction nut 55 between the fan disc 4 and the drum 5, the total height H being equal to the distance D. (
The sub-steps h1) to h3) are repeated so that the fan disc 4 is raised as much as possible above the drum 5. For example, the nut 9 is set at a distance D=6 mm to start the extraction and then the nut 9 is unscrewed by 3 mm at each repetition of the steps h1) to h3) so that the fan disc 4 is 15 mm away from the drum 5 after four cycles.
Such an extraction of the fan disc 4 allows to provide a vertical removal and prevents contact between the screws 8 and the holes embodied in the lobes 16 of the fan disc 4.
As shown in
At the end of the steps a) to i), the module 1 is in its third state E3. The re-installation (or the placement) of the repaired fan disc (or of a new fan disc) is performed directly on the module 1 as it was after the above-mentioned method, i.e. in its third state E3 and placed on the tool 22. The same tool 22 allow to be used to remove the fan disc 4 and also to install it again. During the re-installation, care must be taken to correctly orient the repaired fan disc by aligning a mark associated with the repaired fan disc (e.g. a notch) with the marks on the other components of the module 1. When the repaired fan disc is re-installed, the sealing part 6 of the module 1 is heated so as to allow the repaired fan disc can be press-fitted into the sealing part 6 of the module 1.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1904463 | Apr 2019 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/FR2020/000142 | 4/21/2020 | WO | 00 |
