TOOL AND METHOD FOR DISASSEMBLING AND MOVING A TRV-TYPE TURBINE CASING OF AN AIRCRAFT TURBINE ENGINE

Abstract

A TRV-type turbine casing includes inner and outer annular shrouds that extend one inside the other and about the same axis and are connected together by arms. A tool for disassembling and moving the casing has a lower carriage for moving the tool, and an upper plate to be attached to the turbine casing. The plate is supported by the carriage and includes first members that cooperate with a first annular flange of one of the shrouds to support the casing and axially immobilize the casing relative to the tool. The plate further includes second members that cooperate with a second annular flange of the other shroud in order to prevent and/or guide the rotation of the casing about the axis.

Claims

1. A tool for disassembling and moving a TRV-type turbine casing of an aircraft turbine engine, the turbine casing comprising internal and external annular shells, which extend one inside the other and around a same axis and are connected together by arms, the tool comprising: a lower carriage configured to move the tool, and an upper plate configured to be fastened to the turbine casing the plate being supported by the carriage and comprising first members configured to cooperate with a first annular flange of one of the shells to support the casing and axially immobilize same with respect to the tool, and second members configured to cooperate with a second annular flange of the other of the shells to rotatably guide and/or block the casing about said axis, wherein the first members comprise hooks which are each connected to a knob and movable by the knob from a first unlocking position to a second position that locks and immobilizes the casing.

2. The tool according to claim 1, wherein the first members are supported by a ring sector of the upper plate, the ring sector being configured to be applied axially to the first flange.

3. The tool according to claim 1, wherein each hook is L-shaped and comprises a first branch parallel to said axis and configured to be engaged radially within the first flange and a second branch movable from the first position, in which the second branch extends tangentially or radially inwardly with respect to said axis, to the second position, in which the second branch extends radially outwardly to hold the flange axially tight.

4. The tool according to claim 1, wherein the second members comprise rods parallel to said axis and configured to be engaged in bolt passage orifices of the second flange.

5. The tool according to claim 4, further comprising two rods spaced apart from each other by a predetermined angle with respect to said axis.

6. The tool according to claim 5, wherein the two rods are spaced apart from each other at an angle in a range of 90° to 180° with respect to said axis.

7. The tool according to claim 1, wherein the plate comprises a stationary lower portion connected to the carriage, and an upper portion which is movable with respect to the stationary portion and which comprises at least one portion of said first and second members.

8. The tool according to claim 7, wherein the movable portion is configured to be translated in a direction parallel to said axis.

9. The tool according to claim 7, wherein the upper portion of the plate comprises two side branches oriented in opposite directions and whose opposite ends are connected to each other by the ring sector.

10. The tool according to claim 1, wherein the carriage is provided with wheels for moving the tool over a floor.

11. The tool according to claim 1, wherein the carriage comprises adjusting elements of a height of the plate and at least one pivoting angle of the plate about an axis.

12. A method for disassembling and moving a TRV-type turbine casing of an aircraft turbine engine, in particular when the turbine engine and the casing are located under a wing of an aircraft, the method using a tool according to claim 1 and comprising the steps of: aligning the plate of the tool with the turbine casing, the tool being located on the side of a downstream end of the casing; moving the tool towards the casing until the second members cooperate with the second flange of the external shell, in order to rotatably guide and/or block the casing about its axis in relation to the tool; axially immobilizing the casing on the plate by the first members of the tool; and disassembling the casing and removing the casing by moving the tool supporting the casing.

Description

BRIEF DESCRIPTION OF FIGURES

[0034] Further characteristics and advantages of the invention will become apparent from the following detailed description, for the understanding of which reference is made to the attached drawings in which:

[0035] FIG. 1 illustrates in a very schematic manner the steps of a method for disassembling a turbine casing of an aircraft turbine engine, according to the prior art,

[0036] FIG. 2 illustrates in a very schematic manner the steps of a method for disassembling a turbine casing of an aircraft turbine engine, which can be implemented with the present invention,

[0037] FIG. 3 is a schematic axial section view of the downstream end of an aircraft turbine engine, and shows a TRV-type turbine casing,

[0038] FIG. 4 is a schematic perspective view of the downstream end of an aircraft turbine engine, and shows a step in a disassembling method according to the invention,

[0039] FIG. 5 is a schematic perspective view of the downstream end of the turbine engine of FIG. 4, and shows another step of a disassembling method according to the invention,

[0040] FIG. 6 is another schematic perspective view of the downstream end of the turbine engine of FIG. 5,

[0041] FIG. 7 is another schematic perspective view of the downstream end of the turbine engine of FIG. 5,

[0042] FIG. 8 is a schematic perspective view of the downstream end of the turbine engine of FIG. 4, and shows another step of a disassembling method according to the invention,

[0043] FIG. 9 is a schematic perspective view of the downstream end of the turbine engine of FIG. 4, and shows another step of a disassembling method according to the invention,

[0044] FIG. 10 is another schematic perspective view of the downstream end of the turbine engine of FIG. 4, and shows the step of FIG. 9,

[0045] FIG. 11 is a schematic perspective view of the downstream end of the turbine engine of FIG. 4, and shows another step of a disassembling method according to the invention,

[0046] FIG. 10a is an enlarged view of a detail of FIG. 10,

[0047] FIG. 11a is an enlarged view of a detail of FIG. 11,

[0048] FIG. 12 is a schematic perspective view of the downstream end of the turbine engine of FIG. 4, and shows another step of a disassembling method according to the invention,

[0049] FIG. 13 is a schematic perspective side view of a tool according to an embodiment of the invention,

[0050] FIG. 14 is a schematic front perspective view of the tool of FIG. 13,

[0051] FIG. 15 is a schematic rear perspective view of a plate of the tool of FIG. 13,

[0052] FIG. 16 is a schematic front perspective view of a plate of the tool of FIG. 13,

[0053] FIG. 17 is a larger scale schematic partial cross-sectional view of a detail of the tool of FIG. 13,

[0054] FIG. 18 is a larger scale schematic partial cross-sectional view of a detail of the tool of FIG. 13, and

[0055] FIG. 19 is a larger scale schematic partial cross-sectional view of a detail of the tool of FIG. 13.

DETAILED DESCRIPTION OF THE INVENTION

[0056] As discussed above, there is a need to simplify the dismantling and the maintenance of a turbine casing by allowing its disassembling directly from under the wing 12 of an aircraft. This is schematically represented in FIG. 2 in which the references used are the same as those used in reference to FIG. 1.

[0057] FIG. 3 shows schematically a TRV-type turbine casing 24. This casing 24 comprises two annular shells, respectively internal 24a and external 24b, extending one inside the other and about a same axis A which is the longitudinal axis of the turbine engine 10 and its rotors. The two shells 24a, 24b are connected together by substantially radial arms 26, at least some of which may be tubular to lighten the casing and allow the passage of auxiliaries 28, such as cables or conduits.

[0058] The shells 24a, 24b define between them an annular flow duct for the combustion gases leaving the turbines of the turbine engine located just upstream. This duct is passed through by the arms 26.

[0059] The shells 24a, 24b are cylindrical or frustoconical in shape and comprise at each of their axial ends an annular fastening flange, which may be circular or festooned.

[0060] The upstream flange 24b1 of the external shell 24b is attached to a downstream flange of a turbine casing 30, for example low-pressure, of the turbine engine. The downstream flange 24b2 of this external shell 24b is attached to an upstream flange of the nozzle 18 (FIG. 3). The upstream flange 24a1 of the internal shell 24a is attached to a downstream flange of a cowling 34 of the turbine engine. This cowling 34 may be integrated completely integral or not with the casing 24. The downstream flange 24a2 of the internal shell 24a is attached to an upstream flange of the exhaust cone 20 (FIG. 3).

[0061] FIGS. 4 to 12 show steps of a method for disassembling the turbine casing 24, and FIG. 13 and following show an embodiment of a tool 100 for implementing this method.

[0062] A first step illustrated in FIG. 4 as well as in the second drawing of FIG. 2 (from the left) consists in dismantling the nozzle 18 and the exhaust cone 20 of the turbine engine 10. The turbine engine 10 is attached to the wing 12 of the aircraft and both of these elements are removed from downstream of the turbine engine 10. To do this, the screws or bolts attaching these elements are unscrewed and removed, which allows them to be disengaged from the turbine engine and removed. More specifically, the screws for attaching the flange of the nozzle 18 to the flange 24b2 of the shell 24b are removed to extract the nozzle 18 by axial translation towards downstream, and then the screws for attaching the flange of the cone 20 to the flange 24a2 of the shell 24a are removed to extract the cone 20 by axial translation towards downstream.

[0063] This allows to clear the downstream side of the turbine casing 24, as shown in FIGS. 5 to 7. These figures allow to show details of the turbine casing 24 and of the turbine engine. In the example shown, the flange 24b2 extends radially outwardly and is festooned. The flange 24a2 extends radially inwardly and is also festooned. The flange 24b1 is similar to the flange 24b2, and the flange 24a1 is circular in the example shown. Each flange comprises alternating solid and hollow portions, the solid portions comprising orifices for passage of the screws for attaching the flanges.

[0064] It can also be seen from these figures that the screws for attaching the flanges 24a1, 24b1 are accessible from downstream and can therefore be unscrewed to disengaged the turbine casing 24 from the rest of the turbine engine. The flange 24b1 extends radially outward and its screws are accessible from the exterior of the shell 24b, and the flange 24a1 extends radially inward and its screws are accessible from the interior of the shell 24a.

[0065] The auxiliaries 28 extending through the arms 26 are accessible from both the interior and the exterior of the turbine casing 24 (FIG. 6) and their ends may be disengaged from other elements to allow their removal and the disassembling of the turbine casing 24.

[0066] More specifically, FIGS. 8 to 12 show the disassembling and the moving of the turbine casing 24 by means of the tool 100 which is shown in FIG. 13 and following.

[0067] Essentially, this tool 100 comprises two portions namely: [0068] a lower carriage 102 for moving the tool, and [0069] an upper plate 104 for attaching to the turbine casing 24, said plate 104 being supported by the carriage 102.

[0070] The plate 104 is shown alone in FIGS. 15 and 16. It comprises first members 106 configured to cooperate with one of the flanges of the turbine casing 24 in order to immobilize it axially with respect to the tool, and second members 108 configured to cooperate with another flange of the turbine casing 24 in order to block it in rotation about its axis A and to ensure its centring with respect to this axis.

[0071] In the illustrated example, the members 106 are configured to cooperate with the flange 24a2 and the members 108 are configured to cooperate with the flange 24b1.

[0072] Here, the members 106 are supported by a ring sector 110 of the plate 104, this ring sector 110 being configured to be axially applied to the flange 24a2.

[0073] In the illustrated example, the plate 104 itself comprises two portions, respectively upper and lower, and has a T or cross or +shape.

[0074] The lower portion of the plate 104 is substantially straight and vertical. This lower portion is considered as a stationary segment as opposed to the upper portion which is movable relative to the lower segment.

[0075] The upper portion of the plate comprises two side branches 104a1, 104a2 oriented in opposite directions and whose opposite ends are here connected to each other by the ring sector 110. This ring sector 110 here extends over substantially 180° above these branches 104a1, 104a2.

[0076] The plate 104 comprises a lower end 104a3 for connection to the carriage 102, and may comprise an upper end 104a4 also connected to the ring sector 110. The end 104a3 forms part of the stationary segment of the plate 104, and its end 104a4 forms part of the movable segment.

[0077] The members 106 are distributed over the ring sector 110. The members are three in number in the example shown. Two members 106 are located at the circumferential ends of the ring sector 110, i.e. at the level of the ends 104a1, 104a2. The last member 106 is located substantially in the middle of the ring sector 110, and thus at the level of the end 104a4.

[0078] One of these members 106 is shown in detail in FIG. 18. Each of these members 106 comprises a hook 106a which is connected to a knob 106b and which is movable about an axis B by means of the knob 106b from a first unlocking position to a second position for locking and immobilizing the casing 24. In the position of use, the axis B is substantially parallel to the axis A.

[0079] The hook 106a is generally L-shaped and comprises a first branch 106a1 extending along the axis B and configured to be engaged radially within the flange 24a2, and a second branch 106a2 movable from the first position, in which it extends substantially tangentially or radially inwardly with respect to the axis A, to the second position, in which it extends radially outwardly to hold that flange axially tight (see FIG. 18). The flange 14a2 is thus tightened between the hook and the ring sector 110.

[0080] The members 108 are two in number here. A first of these members is located in the vicinity of the lower end 104a3 of the body 104a of the plate 104 and is thus supported by the stationary segment of the plate. Another member 108 is located on a side extension of one of the branches 104a2 of the body 104a and is thus supported by the movable segment of the plate.

[0081] Each of these members 108 comprises a rod 108a substantially parallel to the axis A and configured to be engaged in a screw passage orifice of the flange 24a2. Due to the position of the members 108, the rods 108a are here spaced apart from each other at an angle of approximately 90° with respect to the axis A.

[0082] FIG. 17 is a larger scale view of the rod 108a of the member 108 located in the vicinity of the end 104a3. This rod 108a is manually movable in axial translation from an advanced position shown in this figure, to a retracted position, and vice versa. For this purpose and in the example shown, the rod 108a is integral with a finger 108b which cooperates with an L-shaped notch 111a of a sheath 111 carried by the plate 104. The finger 108b cooperates with this notch 111a by bayonet effect, i.e. the finger can be brought to both ends of the notch. It is possible to lock the finger 108 in its retracted position or to hold it in its advanced position, for example by means of a spring 112 housed in the sheath 111.

[0083] FIG. 19 is a detail view of the plate 104 and in particular of its aforementioned stationary and movable segments. The movable segment may be moved on the stationary segment by means of a handwheel 114 connected to an endless screw 116. The screwing or the unscrewing of the handwheel leads to a translation forward or backward, along the axis C of the screw, of the movable segment on the stationary segment.

[0084] The carriage 102 of the tool is shown in FIGS. 13 and 14. It comprises wheels 120, here three in number, for moving the tool over a floor.

[0085] The carriage 102 further comprises adjusting elements 118 of a height of the plate 104 and at least one pivot angle of the plate about an axis. The elements 118 thus allow the height of the plate 104 to be adjusted as well as the tilt angles of the plate, for example with respect to each of the axes of an orthonormal reference frame.

[0086] We will now continue with the presentation of the steps of the method for disassembling the turbine casing 24 with reference to FIGS. 8 to 12.

[0087] In FIG. 8, the tool 100 is moved by means of these wheels 120 until downstream of the turbine casing 24.

[0088] The tool 100 is shown so that the ring sector 110 is applied axially against the flange 24a2 of the internal shell 24a of the casing 24 (FIGS. 9, 10 and 10a). For this purpose, the height and the angular position of the plate 104 with respect to the aforementioned angles may be adjusted by means of the aforementioned elements 108. The carriage 102 may be brought as close as possible to the turbine engine 10 and the approach to the ring sector 110 may be made by means of the aforementioned handwheel 114.

[0089] The rods 108a are advanced until their free ends engage in orifices in the flange 24b1 of the external shell 24b. This allows the plate 104 and in particular the ring sector 110 to be centred with respect to the turbine casing 24 (FIGS. 10 and 13).

[0090] The members 106 are then manipulated to hold the flange 24a2 axially tight against the ring sector 110. The turbine casing 24 is then engaged to the tool 100 and can be disengaged from the turbine engine 10. The screws for attaching the flanges 24a1, 24b1 are unscrewed and removed. Some of these screws had to be removed beforehand to engage the rods 108a in these orifices.

[0091] The turbine casing 24 can then be axially removed from the rest of the turbine engine by axial translation (FIGS. 11 and 12). As illustrated in FIGS. 11 and 11a, the environment of the turbine casing 24 is very constrained and its removal may require a succession of small movements facilitated by the wheels 120 and the adjusting elements 118.

[0092] The turbine casing 24 is then removed from the turbine engine 10 and can undergo a maintenance operation before being reassembled, as shown in FIG. 2.