DEVICE FOR REMOVAL OF A FLASHING IN AN AIRCRAFT TURBOMACHINE AND ASSOCIATED METHOD

Abstract

Device (40) for removing a shim (18) interposed between the foot (12) of a blade (10) and the bottom of a cavity (15) of a rotor disc (13) in an aircraft turbomachine, this device (40) comprising: - a flexible tube (50) configured to be inserted into the turbomachine, - a clamp (60) located at the distal end (50b) of the tube (50) and configured to clamp the shim (18) for its removal, and - a cable (70) extending inside the tube (50) and having an end (70a) connected to the clamp (60) for its actuation, and an opposite end (70b) connected to a handle (80) which is adapted to be manipulated by an operator in order to move the cable (70) in the passage (52) and thus actuate the clamp (60). Figure for the abbreviation: Figure 3

Description

Title of the invention: DEVICE FOR REMOVING A FOIL IN AN AIRCRAFT TURBOMACHINE AND ASSOCIATED METHOD Technical field of the invention

[0001] The present invention relates to a method for removing a foil inserted between the root of a blade and the bottom of a cell of a rotor disk in an aircraft turbomachine, as well as a method using this device. Technical background

[0002] Conventionally, an axial turbine of a turbomachine consists of a succession of axial stages (along the axis of circulation of the gas flows) arranged one behind the other. Each stage comprises a bladed wheel forming the rotor and a bladed distributor forming the stator. The wheel is rotated opposite the corresponding distributor.

[0003] In the present application, upstream and downstream are defined with respect to the normal flow direction of the air flows (from upstream to downstream) through the turbomachine. The term "axis of the turbomachine" refers to the axis of rotation of the main rotor of the turbomachine. The axial direction corresponds to the direction of the axis of the turbomachine, and a radial direction is a direction perpendicular to the axis of the turbomachine and intersecting this axis. Similarly, an axial plane is a plane containing the axis of the turbomachine, and a radial plane is a plane perpendicular to this axis. The adjectives "inner" and "outer" are used with reference to a radial direction so that the inner part of an element is, in a radial direction, closer to the axis of the turbomachine than the outer part of the same element.The stacking axis of a blade is the axis perpendicular to the turbomachine axis, which passes through the center of gravity of the innermost section of the blade blade (i.e., the section closest to the turbomachine axis). Typically, a turbomachine blade comprises a blade extending along the stacking axis of the blade, between the proximal and distal (i.e., inner and outer) ends of the blade.

[0004] The moving wheel is conventionally made up of an annular disc centered on the axis of rotation of the wheel, on which a plurality of blades are fixed.

[0005] An example of a blade is shown in [Fig. 1]. A blade of this type is described in patent document FR-A1-3 079 847. This blade 10 comprises a blade 16 extending along the stacking axis X of the blade, between the proximal 10a and distal 10b ends of the blade 10. At its proximal end 10a, the blade 10 comprises a lower platform 19 and a root 12 by which it is fixed to a disc 13 (not re- presented in [Fig.l]).

[0006] The disc 13 comprises at its periphery cells 15 oriented substantially parallel to the axis of the disc 13 and arranged alternately with teeth 17 of the disc 13. Each blade 10 is held on the disc 13 by insertion of the root 12 into one of the cells 15 of the disc 13. The root 12 is held radially by shape cooperation by the teeth 17 of the disc 13.

[0007] At its distal end 10b, the blade 10 has a heel 14.

[0008] The heel 14 comprises a platform 20 externally delimiting the flow path of the gas circulating between the blades 16, and having opposite lateral edges 21, 22. The platform 20 comprises an upstream part 24 called the “upstream spoiler” and a downstream part 28 called the “downstream spoiler”. The heel 14 also comprises upstream 31 and downstream 32 sealing lips extending radially outwards from the outer face of the platform 20. Each of the lateral edges 21, 22 of the platform has, between the upstream 31 and downstream 32 lips, a substantially “U” shaped profile. In the case of other blades, this profile may take the form of a “Z” or a “V”, for example.

[0009] Foils 18 may be arranged in the cells 15 between the roots 12 of the blades 10 and the disc 13 so as to prevent wear of these parts. The foils 18 thus have a protective part function and guarantee the mechanical integrity of the blades 10 and the disc 13.

[0010] Conventionally, the foils 18 are mounted around the feet 12 of the blades 10, before being inserted into the cells 15 of the discs 13.

[0011] The foils 18 can be held in position on the feet 12 of the blades 10 by at least one folded tab 23, upstream or downstream.

[0012] In operation, the foils 18 can move axially progressively, in particular due to the effects of thermal expansion and the stresses involved. The movement of the foils 18 can go as far as damaging the tabs 23.

[0013] The foils 18 are then no longer held on the roots 12 of the blades 10. They can disengage from the roots 12 of the blades 10 and partially then completely exit the housings formed by the cells 15.

[0014] This disengagement can lead to the removal and disassembly of the engine to put the shims back in position or to change them.

[0015] If such removal and disassembly are not carried out, the wear between the blade and the disc is greater. The mechanical strength between these parts is then degraded.

[0016] Furthermore, a partially disengaged foil can seriously damage the blading and the disc, or even the bladings, particularly those located downstream, when it disengages completely.

[0017] The Applicant has already proposed in document FR-A1-3 124 215 a device and a method for re-engaging a blade foil of a rotor wheel in an aircraft turbomachine, without requiring removal or disassembly of the engine or turbine of the turbomachine.

[0018] Alternatively to re-engagement, it might be preferable to remove the engaged, or partially disengaged, foil, and the present invention provides a simple, effective and economical solution to this end. Summary of the invention

[0019] The invention thus proposes a device for removing a foil inserted between the root of a blade and the bottom of a cell of a rotor disk in an aircraft turbomachine, this device comprising:

[0020] - a flexible tube configured to be inserted into the turbomachine and to pass between blades carried by the disk, this tube comprising a proximal end intended to remain outside the turbomachine, and a distal end intended to be positioned at the level of the foil to be removed, this tube comprising an internal passage extending over its entire length,

[0021] - a clamp located at the distal end of the tube and configured to clamp the clinging for removal, this clamp comprising two arms articulated around a pivot and being actuated to move the arms and thus close or open the clamp, and

[0022] - a connecting element extending inside the passage of the tube and comprising a end connected to the arms of the clamp for actuation thereof, and an opposite end located at the proximal end of the tube and connected to a handle or forming a handle which is capable of being manipulated by an operator in order to move the connecting element in the passage and thus actuate the clamp.

[0023] The invention therefore proposes a solution for removing a foil, whether in place or partially disengaged, from outside the turbomachine. A foil can thus be removed during a maintenance operation, including when the turbomachine equips an aircraft, that is to say during an “under-wing” operation. Removal may be preferred to re-engagement of the foil, for example. Removal may also precede replacement of the foil with a new one.

[0024] The device according to the invention may comprise one or more of the following characteristics, taken in isolation from one another or in combination with one another:

[0025] - the arms comprise hooking teeth;

[0026] - the teeth of one of the arms are different from the teeth of the other of the arms and / or the teeth of one of the arms do not engage by complementarity of shapes with the teeth of the other of the arms;

[0027] - the arms are bent;

[0028] - the end of the connecting element is connected to the arms of the clamp by two connecting rods including a first connecting rod which has one end hinged to one end of one of the arms and an opposite end connected to the connecting element, and a second connecting rod which has one end hinged to one end of the other of the arms and an opposite end connected to the connecting element;

[0029] - the connecting rods are housed inside the tube;

[0030] - the elastic member is mounted at the distal end of the tube and urges the clamp in its opening position;

[0031] - the elastic member is a helical compression spring;

[0032] - the elastic member is mounted between a cup mounted inside the tube, and the end of the connecting element connected to the arms of the clamp;

[0033] - the handle is formed by a loop of the end of the connecting element;

[0034] — the connecting element has an elongated shape;

[0035] - the connecting element is a cable, a chain, a band, a rod, a sling, or a jack.

[0036] The present invention also relates to a method for removing a foil inserted between the root of a blade and the bottom of a cell of a rotor disk in an aircraft turbomachine, this method using a device as described above.

[0037] The method may comprise the following steps:

[0038] - the insertion of the device into the turbomachine and the passage of the device tube between blades carried by the disc,

[0039] - positioning the pliers so that part of the foil to be removed is located between the arms of the clamp in the open position,

[0040] - closing the clamp and tightening the foil between the arms of the clamp, in ma pulling the handle and moving the connecting element into the tube passage, and

[0041] - the removal of the foil. Brief description of the figures

[0042] The invention will be better understood and other details, characteristics and advantages of the invention will appear more clearly on reading the following description given by way of non-limiting example and with reference to the appended drawings in which:

[0043] [Fig-1] [Fig.l] is a schematic perspective view of a moving wheel blade turbine,

[0044] [Fig.2] [Fig.2] is a schematic perspective view of a foil in a unwanted disengagement position,

[0045] [Fig.3] [Fig.3] is a schematic perspective view of a step of inserting a removal device according to an exemplary embodiment of the invention,

[0046] [Fig.4] [Fig.4] is an enlarged view of a portion of [Fig.3], and shows the clamp of the device in the open position,

[0047] [Fig.5] [Fig.5] is a schematic perspective and sectional view of the clamp of the device in the closed position,

[0048] [Fig.6] [Fig.6] is a schematic perspective view of a step of closing the clamp and clamping the foil between the arms of the clamp, and

[0049] [Fig.7] [Fig.7] is a schematic perspective view of a foil removal step. Detailed description of the invention

[0050] Figures 1 and 2 have been described in the above.

[0051] The invention relates to a method and a device for removing a foil 18.

[0052] This foil 18 is interposed between the root 12 of a blade 10 and the bottom of a cell 15 of a rotor disk 13 in an aircraft turbomachine.

[0053] The foil 18 to be removed can be correctly engaged in the cell 15 or partially disengaged from the cell 15 as illustrated in [Fig.3].

[0054] The foil 18 can be gripped by the removal device at one of its ends and for example by one of its aforementioned tabs 23.

[0055] An embodiment of the removal device 40 according to the invention is illustrated in figures 3 and following which also show steps of use of this device 40.

[0056] The device 40 essentially comprises:

[0057] - a flexible tube 50,

[0058] - a clamp 60, and

[0059] - a connecting element 70, one end of which forms a handle 80 or is connected to a handle for actuating the clamp 60.

[0060] The tube 50 is configured to be inserted into the turbomachine and to pass between blades 10 carried by the disk 13.

[0061] The tube 50 comprises a proximal end 50a intended to remain outside the turbomachine, and a distal end 50b intended to be positioned at the level of the foil 18 to be removed.

[0062] The tube 50 comprises an internal passage 52 which extends over the entire length of the tube and which therefore opens at its ends 50a, 50b.

[0063] The clamp 60 is located at the distal end 50b of the tube 50 and is configured to clamp the foil 18 for removal.

[0064] The clamp 60 comprises two arms 62 articulated around a pivot 63 in the manner of scissors for example.

[0065] The clamp 60 is actuated to move the arms 62 and thus close or open the clamp. The clamp is in its open or opening position in [Fig.4] and in its closed or closing position in [Fig.5].

[0066] In the example shown, the arms 62 comprise hooking teeth 64 intended to facilitate the gripping of the foil 18. The teeth 64 are thus located at the ends of the arms 62 intended to grip the foil 18 between them.

[0067] The teeth 64 of one of the arms 62 are preferably different from the teeth 64 of the other of the arms, as in the example shown. As a variant or as an additional characteristic, the teeth 64 of one of the arms 62 do not engage by complementarity of shapes with the teeth 64 of the other of the arms 62 as is visible in [Fig.5] for example.

[0068] The arms 62 may be bent in order, for example, to facilitate the positioning of the foil 18 between the arms 62 of the clamp 60. In the example shown, the ends of the arms 62 intended to grip the foil 18 are inclined at an angle of between 30 and 60° relative to the rest of the arms 62.

[0069] It can be seen in the drawings and in particular in figures 4 and 5 that the clamp 60 and in particular the arms 62 are slidably mounted in the end 50b of the tube 50. In its closed position of [Fig.5], the clamp 60 is housed more in the tube 50 than in its open position of [Fig.4].

[0070] The movement of the clamp 60 inside the tube 50 causes the arm to close or open, or conversely the closing or opening of the arm causes the movement of the clamp 60 inside the tube 50.

[0071] The connecting element 70 is for example a cable. Alternatively, it could be another connecting element chosen for example from: a chain, a band, a rod, a sling, or a jack.

[0072] Although the following description relates to the use of a cable as a connecting element, it applies to the other examples of connecting elements discussed above.

[0073] The cable 70 extends inside the passage 52 of the tube 50 and has an end 70a connected to the arms 62 of the clamp 60 for its actuation, and an opposite end 70b located at the proximal end 50a of the tube 50 and connected to the handle 80 or forming this handle 80.

[0074] In the example shown, the handle 80 is formed by a loop of the end 70b of the cable 70.

[0075] The handle 80 is capable of being manipulated by an operator in order to move the cable 70 in the passage 52 and thus actuate the clamp 60.

[0076] In the example shown, the end 70a of the cable 70 is connected to the arms 62 of the clamp 60 by two connecting rods 72, 74.

[0077] The connecting rod 72 has one end articulated on one end of one of the arms 62 and an opposite end connected to the cable 70. The connecting rod 74 has one end articulated on a end of the other of the arms 62 and an opposite end connected to the cable 70.

[0078] The connecting rods 72, 74 can be housed inside the tube 50 as can be seen in Figures 4 and 5.

[0079] It can be seen in the drawings and in particular in figures 4 and 5 that the connecting rods 72, 74 are slidably mounted in the end 50b of the tube 50.

[0080] The closing of the clamp 60 can be carried out in the following way. A tensile force is applied by an operator to the handle 80 who therefore pulls on this handle 80. The cable 70 moves inside the passage 52 of the tube 50 which transmits the tensile force to the connecting rods 72, 74 then to the arms 62 of the clamp 50. In the case shown, this traction causes a closing of the clamp 60 and therefore a bringing together of the toothed ends of the arms 62 which are able to grip the foil 18 between them.

[0081] The opening of the clamp 60 can be carried out in the following way. A pushing force is applied by an operator to the handle 80 who therefore pushes on this handle 80. The cable 70 moves inside the passage 52 of the tube 50 which transmits the pushing force to the connecting rods 72, 74 then to the arms 62 of the clamp 50. In the case shown, this pushing causes an opening of the clamp 60 and therefore a moving away of the toothed ends of the arms 62.

[0082] Alternatively, the reverse would be possible. That is to say, pulling on the handle 80 could cause the clamp 60 to open, and pushing on the handle 80 could cause the clamp 60 to close. It would then be sufficient to modify the assembly of the connecting rods 72, 74 and the arms 62 to achieve this end.

[0083] The device 40 can be configured to adopt one of the positions, open or closed, by default, that is to say in the absence of force applied to the handle 80.

[0084] For this, an elastic member 90 can be mounted at the distal end 50b of the tube 50 and can urge the clamp 60 into its open position for example, as in the example shown.

[0085] The elastic member 90 is for example a helical compression spring.

[0086] The elastic member 90 can be mounted between a cup 92 mounted inside the tube 50, and the end 70a of the cable 70 connected to the arms 62 of the clamp 60. In practice, the end 70a of the cable 70 can form a loop 70c which is crossed by a transverse finger 94 on which the ends of the connecting rods 72, 74 are articulated ([Fig.5]). The member 90 can bear on the finger 94 or the loop 70c.

[0087] In [Fig.4] for example, there is no tensile force applied to the cable 70 and the slightly constrained member 90 applies a return force which forces the clamp 60 to adopt its open position.

[0088] In [Fig.5] for example, the tensile force applied to the cable 70 causes the compression of the member and the displacement of the clamp 60 into its position of closing.

[0089] The invention also relates to a method for removing a foil 18 using the device 40 according to the invention.

[0090] The method comprises for example the following steps which are partially represented by figures 3, 6 and 7.

[0091] The method comprises a step of inserting the device 40 into the turbomachine and passing the tube 50 of the device 40 between the blades 13 carried by the disk 15 ([Fig.3]).

[0092] The method comprises a step of positioning the clamp 60 so that a portion of the foil 18 to be removed is located between the arms 62 of the clamp in the open position.

[0093] The method comprises a step of closing the clamp 60 and clamping the foil 18 between the arms 62 of the clamp 60, by manipulating the handle 80 and moving the cable 70 in the passage 52 of the tube 50 ([Fig.6]).

[0094] Finally, the method comprises a step of removing the foil 18 ([Fig.7]) and removing it from the turbomachine if necessary.

[0095] The present invention provides several advantages, including the possibility of removing a foil without dismantling the turbomachine.

Claims

Claims

1. Device (40) for removing a foil (18) inserted between the root (12) of a blade (10) and the bottom of a cell (15) of a rotor disk (13) in an aircraft turbomachine, this device (40) comprising: - a flexible tube (50) configured to be inserted into the turbomachine and to pass between blades (10) carried by the disk (13), this tube (50) comprising a proximal end (50a) intended to remain outside the turbomachine, and a distal end (50b) intended to be positioned at the foil (18) to be removed, this tube (50) comprising an internal passage (52) extending over its entire length, - a clamp (60) located at the distal end (50b) of the tube (50) and configured to clamp the foil (18) in order to withdrawal, this clamp (60) comprising two arms (62) articulated around a pivot (63) and being actuated to move the arms (62) and thus close or open the clamp (60),and - a connecting element (70) extending inside the passage (52) of the tube (50) and comprising an end (70a) connected to the arms (62) of the clamp (60) for its actuation, and an opposite end (70b) located at the proximal end (50a) of the tube and connected to a handle (80) or forming a handle which is capable of being manipulated by an operator in order to move the connecting element (70) in the passage (52) and thus actuate the clamp (60).,

2. Device (40) according to claim 1, wherein the arms (62) comprise hooking teeth (64).

3. A device (40) according to claim 2, wherein the teeth (64) of one of the arms (62) are different from the teeth (64) of the other of the arms (62) and / or the teeth (64) of one of the arms (62) do not engage by form complementarity with the teeth (64) of the other of the arms (62).

4. Device (40) according to one of claims 1 to 3, in which the arms (64) are bent.

5. Device (40) according to one of claims 1 to 4, in which the end of the connecting element (70) is connected to the arms (62) of the clamp (60) by two connecting rods (72, 74) including a first connecting rod (72) which has one end articulated on one end of one of the arms (62) and an opposite end connected to the connecting element (70), and a second connecting rod (74) which has one end articulated on one end of the other of the arms (62) and an opposite end connected to the cable (70).

6. Device (40) according to claim 5, in which the connecting rods (72, 74) are housed inside the tube (50).

7. Device (40) according to one of claims 1 to 6, in which an elastic member (90) is mounted at the distal end (50b) of the tube (50) and biases the clamp (60) into its open position.

8. A device (40) according to claim 7, wherein the elastic member (90) is a helical compression spring.

9. Device (40) according to claim 7 or 8, in which the elastic member (90) is mounted between a cup (92) mounted inside the tube (50), and the end (70a) of the connecting element (70) connected to the arms (62) of the clamp (60).

10. Device (40) according to one of the preceding claims, wherein the handle (80) is formed by a loop (70c) of the end of the connecting element (70).

11. Device (40) according to one of the preceding claims, in which the connecting element is a cable, a chain, a band, a rod, a sling, or a jack.

12. Method for removing a foil (18) inserted between the root (12) of a blade (10) and the bottom of a cell (15) of a rotor disk (13) in an aircraft turbomachine, this method using a device (40) according to one of the preceding claims.

13. Method according to the preceding claim, in which it comprises the following steps: - inserting the device (40) into the turbomachine and passing the tube (50) of the device (40) between blades (10) carried by the disc (14), - positioning the clamp (60) so that a part of the foil (18) to be removed is located between the arms (62) of the clamp (60) in the open position, - closing the clamp (60) and clamping the foil (18) between the arms (62) of the clamp (60), by manipulating the handle (60) and moving the connecting element (70) in the passage (52) of the tube (50), and - removing the foil (18).

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