METHOD FOR MOUNTING AN AXLE IN A BOGIE, AND ASSOCIATED INSTALLATION

Abstract

Method for mounting an axle (12) in a bore (14) of a bogie (16) mounted on a landing gear (18) of an aircraft, the landing gear (18) being in a deployed position, the bore (14) extending in a substantially horizontal direction, called the axle installation direction, between a first open end (14a) and a second open end, the method comprising:a) providing a movable supporting structure (30) comprising means for moving the axle (12) movable in a direction substantially parallel to the axle installation direction,b) installing the axle (12) on the axle moving means,c) aligning the axis (C) of the axle (12) with the axis (B) of the bore (14),d) introducing the axle (12) into said bore (14) of the bogie (16) by moving the axle moving means (12) in the direction substantially parallel to the axle installation direction.Abstract figure: Figure 1.

Description

Title of the invention: METHOD FOR MOUNTING AN AXLE IN A BOGIE, AND ASSOCIATED INSTALLATION Technical field

[0001] The present disclosure relates to a method of mounting an axle in a bore of a bogie for an aircraft, and an installation intended for implementing the method. Prior art

[0002] Conventionally, an aircraft, such as an airplane, comprises a landing gear which is deployed during takeoff and landing operations of the airplane. The landing gear comprises at least one bogie extending in a longitudinal direction. One or more bore(s) having a first end and a second end open pass through the bogie in a direction substantially transverse to the longitudinal direction of the bogie. When the bogie is installed in the airplane and the landing gear is deployed, an axis of each bore extends in a substantially horizontal direction, that is to say, substantially parallel to the ground on which the airplane rests.

[0003] Each bore receives an axle carrying a wheel on each side of the bogie. In service, the axle may develop defects that require its replacement in order to ensure the safety of the aircraft during takeoff and landing.

[0004] To this end, during an axle maintenance operation, the assembly formed by the bogie and the axles is dismantled from the landing gear and sent to the workshop. In a first step, the operator forcibly removes the axles from the bores of the bogie. In a second step, the bogie is positioned in such a way that the axes of the bores are oriented vertically. In a third step, a new axle is aligned with a bore and then engaged vertically in it. This operation is repeated as many times as there are bores. It is understood that these maintenance operations are carried out in the workshop, which proves to be complicated and expensive, in particular due to the immobilization of the aircraft. Summary

[0005] The present disclosure improves the situation.

[0006] To this end, a method is proposed for mounting an axle in a bore of a bogie mounted on a landing gear of an aircraft, the landing gear being in a deployed position, the bore of the bogie extending in a substantially horizontal direction, called the axle installation direction, between a first open end and a second open end, the method comprising: (a) supply of a mobile supporting structure comprising means of movement of the axle movable in a direction substantially parallel to the direction of installation of the axle, b) installation of the axle on the axle moving means, c) alignment of the axle axis with the bore axis, d) introduction of the axle into said bore of the bogie by moving the axle moving means in the direction substantially parallel to the direction of installation of the axle.

[0007] With the axle being inserted into the bogie bore in the axle installation direction, which is substantially horizontal, the mounting method allows the axle to be installed in the bogie bore without the need to remove the bogie from the landing gear. The axle may even be installed under the wing of the aircraft. This simplifies the mounting of the axle in the bore and speeds up the mounting of the axle in the bore, thereby reducing the costs associated with immobilizing the aircraft.

[0008] According to one aspect of the invention, the method comprises a step prior to step d) comprising the introduction of the axle in a horizontal position, for a given time, for example one hour, in a tank filled with liquid nitrogen.

[0009] Introducing the axle into the tank filled with liquid nitrogen allows the axle to be cooled to a temperature of approximately -200°C, which causes the axle to shrink, facilitating its insertion into the bore. Once in the bore, the axle temperature rises to room temperature, which causes the axle to expand, leading to an increase in its external diameter until it self-tightens at room temperature in the bore.

[0010] According to one aspect of the invention, step c) comprises: - the positioning of a marker on the mobile supporting structure and in such a way that the axis of the bore intercepts said marker, and - positioning the axle so that its axis is aligned according to the installation direction with the said mark.

[0011] By positioning the marker so as to be intercepted by the axis of the bogie bore, the alignment between the axle axis and the marker also implies that the axle axis is aligned with the axis of the bore. The axle can therefore be easily introduced into the bore without the risk of collisions between the axle and the bore during this introduction.

[0012] According to one aspect of the invention, the marker is arranged in a vertical plane comprising the installation direction, this plane corresponding to a lifting plane of the axle axis.

[0013] The mark being arranged in the lifting plane of the axle axis, it is sufficient only to adjust the position of the axle axis in a substantially vertical direction to align the mark and said axle axis, which makes it possible to produce the alignment of the axle axis with the axis of the bogie bore.

[0014] According to one aspect of the invention, the method comprises mounting a laser beam device in the bore of the bogie such that the axis of the laser beam is coaxial with the axis of the bore of the bogie.

[0015] According to the invention, the laser beam will be visible on the mark. The axis of the laser beam being coaxial with the axis of the bore of the bogie, an alignment between the mark and the laser beam makes it possible to guarantee the alignment between the axis of the bore and the mark.

[0016] According to one aspect of the invention, step d) is preceded by a step comprising the mounting of a sleeve around a first end of the axle which is arranged opposite the bore of the bogie in the direction of installation of the axle.

[0017] According to the invention, the sleeve can be made of a flexible material, such as plastic. This sleeve makes it possible to absorb any collisions that may occur between the axle and the bore of the bogie during step d).

[0018] According to another aspect, there is provided an installation for implementing a method of mounting an axle in a bore of a bogie mounted on a landing gear of an aircraft, the landing gear being in a deployed position, the bore extending in a substantially horizontal direction, called the axle installation direction, between a first open end and a second open end, the installation comprising: - a mobile supporting structure, - means for aligning the axis of the bogie bore with the axis of the axle, - means for moving the axle into a position for insertion into the bogie bore and for mounting the axle in the bogie bore.

[0019] The installation allows the axle to be mounted in the bore in a substantially horizontal direction. There is therefore no need to dismantle the bogie of the landing gear to mount the axle in the bore. The installation may in particular be arranged under the wing of the aircraft in order to mount the axle directly in this position. The installation therefore makes it possible to simplify the mounting of the axle and reduce its cost.

[0020] According to one aspect of the invention, the installation further comprises a tank filled with liquid nitrogen.

[0021] The tank filled with liquid nitrogen allows the axle to be cooled before being inserted into the bore. This causes the axle to contract, making it easier to insert into the bore. Once in the bore, the axle temperature rises to room temperature, causing the axle to expand, allowing the axle to be tightly fitted into the bogie bore without any other fasteners.

[0022] According to one aspect of the invention, the alignment means comprise a marker carried by the mobile supporting structure and a laser beam device shaped to be installed in the bogie bore so that the axis of the laser beam is coaxial with the axis of the bogie bore.

[0023] According to the invention, a position of the marker will be adjusted so that the laser beam intercepts the marker. The axis of the laser beam being coaxial with the axis of the bore of the bogie, the installation makes it possible to easily align the marker and the axis of said bore.

[0024] According to one aspect of the invention, the installation further comprises means for moving the reference mark comprising at least one rolling element configured to move the supporting structure along a horizontal plane, and at least one element for lifting the supporting structure configured to move the supporting structure in translation along a substantially vertical direction.

[0025] By means of the rolling element and the lifting element, the marker can be moved along the horizontal plane and in the substantially vertical direction until the laser beam intercepts the marker, thereby ensuring alignment between the marker and the axis of the bore.

[0026] According to one aspect of the invention, the supporting structure comprises an upper frame carried by a plurality of vertical uprights, the upper frame supporting the means for moving the axle into a position for insertion into the bore of the bogie and for mounting the axle in the bore of the bogie.

[0027] The axle displacement means are in particular arranged so that, once the mark is aligned with the axis of the bore, the axle displacement means move in a direction substantially parallel to the axis of the bore. This makes it easy to align the axle with the bore.

[0028] According to one aspect of the invention, the movement means comprise a rail carried by the upper frame and a hoist mounted for translational movement on the rail in the direction of installation of the axle.

[0029] The hoist allows the axle to be lifted to the alignment position between the axle axis and the bore axis. The hoist being mounted for translational movement on the rail in the axle installation direction, the axle is directly introduced into the bore from this movement of the hoist once the axle is aligned with the axis of the bogie bore

[0030] According to one aspect of the invention, the marker is mounted fixed relative to the rail and arranged in a plane comprising the direction of installation of the axle and the direction of translational movement of the hoist on the rail.

[0031] The marker being mounted fixed relative to the rail, the movements of the supporting structure thanks to the rolling element and the lifting element do not modify the relative position of the marker with respect to the rail.

[0032] According to one aspect of the invention, the hoist is configured so that in the high position, the axle is necessarily positioned with its axis aligned with the reference mark.

[0033] The alignment between the axle and the reference mark is thus obtained by positioning the hoist in the high position. The alignment between the axle and the reference mark is therefore obtained easily and by limiting the risks of error. Brief description of the drawings

[0034] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings, in which: Fig.l

[0035] [Fig.l] is a schematic perspective view of an installation for mounting an axle on a bogie installed on a landing gear of an aircraft according to the invention. Fig. 2

[0036] [Fig.2] is a schematic view of the installation and landing gear of the [Fig.l] and seen from a different orientation. Fig. 3

[0037] [Fig.3] is a schematic perspective view of a supporting structure of the installation of figures 1 and 2 according to the invention. Fig. 4

[0038] [Fig.4] is a schematic perspective view of an axle support of the installation of figures 1 and 2 according to the invention. Fig. 5

[0039] [Fig.5] is a schematic perspective view of a tank of the installation of figures 1 and 2 according to the invention. Fig. 6

[0040] [Fig.6] is a schematic perspective view of the axle support of [Fig.4] supporting the axle and introduced into the tray of [Fig.5]. Fig. 7

[0041] [Fig.7] is a schematic perspective view of the axle support of [Fig.4] supporting the axle, and the tray of [Fig.5]. Fig. 8

[0042] [Fig.8] is a schematic perspective view of a laser of the installation of figures 1 and 2 according to the invention and of a detail of the bogie. Fig. 9

[0043] [Fig.9] is a schematic perspective view of a detail of the bogie when the axle supported by the axle support is introduced into the bogie bore. Description of the embodiments

[0044] In the present description, the different elements will be defined in the three perpendicular directions of space. In particular, an orthonormal reference frame will be used comprising a first direction X, a second direction Y and a third Z direction orthogonal to each other. The first X direction and the second Y direction are substantially horizontal, so as to form between them a substantially horizontal XY plane. The third Z direction is substantially vertical and forms an XZ plane with the first X direction, as well as a YZ plane with the second Y direction. The XZ and YZ planes are substantially vertical.

[0045] Figures 1 and 2 show an installation 10 for mounting an axle 12 in a bore 14 of a bogie 16 which is preferably mounted on a landing gear 18 of an aircraft, for example an airplane.

[0046] The bogie 16 has an elongated shape and extends between two open ends 20. The bogie 16 has in particular a substantially cylindrical shape with axis A. Advantageously, the bogie 16 is made of titanium.

[0047] The bogie 16 comprises a plurality of bores 14. In the example of Figures 1 and 2, the bogie 16 comprises two bores 14, but this number is not limiting, the bogie 16 being able to comprise a single bore or more than two bores.

[0048] Each bore 14 extends between a first open end 14a and a second open end 14b such that the bore 14 is a through bore. Each bore 14 has, for example, a substantially cylindrical section of axis B, the axis B being substantially perpendicular to the axis A of the bogie 16. Advantageously, each open end 20 of the bogie 16 communicates with one of the bores 14.

[0049] In Figures 1 and 2, the landing gear 18 is in a deployed position, that is, a normal position of use of the landing gear 18 in which the wheels of the landing gear, not shown, are in contact with the ground. In this deployed position, the axis A of the bogie 16 extends substantially parallel to the first direction X and the axis B of each bore 14 extends substantially parallel to the second direction Y.

[0050] The axle 12 has an elongated tubular shape, with a substantially cylindrical section, extending between a first end 12a and a second end 12b. Advantageously, a cavity 22 extends inside the axle 12 between the first end 16a and the second end 16b. The axle 12 therefore comprises an external wall and an internal wall, the internal wall delimiting the cavity 22 of the axle. The cavity 22 is, preferably, substantially cylindrical with axis C. When the axle is mounted in the bore of the bogie, the axis B of the bore of the bogie and the axis C of the axle are coaxial, as illustrated in Figures 1 and 2.

[0051] The axle 12 comprises a first end portion 12c, a central portion 12d and a second end portion 12e. The central portion 12d extends between the first and second end portions 12c, 12e. The first end portion 12c and the second end portion 12e extend between the central portion 12d and, respectively, the first end 12a and the second end 12b of the axle 12.

[0052] A first bore 24, visible in [Fig. 6], passes substantially radially through the outer wall of the axle 12. The first bore 24 is arranged on the first end portion 12c of the axle 12. A second bore, similar to the first bore but not visible in the figures, is preferably arranged on the second end portion 12e of the axle 12. As will be detailed, the second bore makes it possible to orient and maintain the axle 12 in position in an axle support 60 which will be described in detail with reference to [Fig. 4]. Advantageously, the first bore and the second bore are aligned along an axis parallel to the axis C of the axle. On the central portion 12d of the axle 12, a third bore 26, illustrated in [Fig.7], passes through the inner and outer walls of the axle 12. The third bore 26 is arranged at substantially 90° around the axis C relative to the first bore 24.The third bore is advantageously at the same distance from the first and second ends 12a, 12b of the axle 12.

[0053] As will be detailed later, in particular with reference to [Fig.7], the first and second end portions 12c, 12e advantageously have a cross-section substantially smaller than a cross-section of the central portion. By "cross-section" is meant an external section of the axle 12 obtained by projection onto the XZ plane when the axle 12 extends substantially parallel to the second direction Y. Preferably, the cross-section of the central portion 12d of the axle 12 has a dimension substantially equal to that of the bore 14, so as to be able to insert the axle 12 into the bore 14 as will be explained later.

[0054] Preferably, the axle 12 is made of metal, for example steel.

[0055] We now describe the installation with reference to the figures.

[0056] The installation 10 comprises a supporting structure 30, or gantry, of which [Fig. 3] shows an isolated view. [Fig. 1] illustrates the supporting structure 30 in use and at the end of assembly of an axle 12 in a bore 14 of a bogie 16.

[0057] The supporting structure 30 advantageously comprises several removable parts. In particular, the supporting structure comprises a plurality of first uprights 32 and a plurality of second uprights 34. In a dismantled position of the supporting structure, not illustrated, these parts are isolated from each other, and can adopt any position in space.

[0058] The arrangement of these parts will now be detailed when the supporting structure is in a mounted position, illustrated in Figures 1 to 3. In this mounted position, the plurality of first uprights 32 extends in a plane substantially parallel to the XY plane, substantially horizontal, while the plurality of second uprights 34 extends in the Z direction, substantially vertical. For this reason, and for the sake of semantic simplification, in what follows the first uprights will be called "uprights horizontal” and the second uprights will be called “vertical uprights”.

[0059] The supporting structure comprises at least three horizontal uprights 32 and in the present case it comprises four horizontal uprights 32. In the figures, two horizontal uprights 32 extend substantially in the first direction X and two other horizontal uprights 32 extend substantially in the second direction Y.

[0060] Each horizontal upright 32 comprises two opposite end portions. Each end portion is adapted to connect two horizontal uprights together. In particular, each end portion of the horizontal uprights 32 extending substantially parallel to the X direction is connected to one of the end portions of one of the horizontal uprights extending substantially parallel to the Y direction. For this purpose, each end portion of the horizontal uprights may be provided with at least one connector 36 or at least one bore (not visible).

[0061] Each bore extends in a plane substantially parallel to the XY plane and passes through the horizontal upright 32 in which it is included in a direction substantially perpendicular to the direction of extension of this upright. Thus, for example, for the horizontal uprights 32 extending substantially in the X direction, a bore made in one of their end portions extends substantially in the Y direction.

[0062] Each connector 36 extends from the respective end portion in the direction of extension of the horizontal upright 32 with which this end portion is connected. According to a non-limiting exemplary embodiment of the invention, each connector 36 comprises two assembly tabs 36a, 36b arranged opposite each other. Each assembly tab 36a, 36b comprises a hole (not visible in the figures). The holes of the two assembly tabs 36a, 36b are aligned with each other.

[0063] In order to connect two horizontal uprights 32, the horizontal upright 32 comprising the bore is arranged between the assembly tabs 36a, 36b of the connector of the other horizontal upright 32 so that the holes of the assembly tabs and the bore are aligned. A removable connecting element 38, such as a rod, can then be arranged so as to pass through the two holes of the connector 36 and the bore. The two horizontal uprights 32 are thus connected to each other and held in position relative to each other.

[0064] When all the horizontal uprights 32 are connected, they form an upper frame 40 of the supporting structure 30.

[0065] Each end portion is further adapted to connect the horizontal uprights 32 to the vertical uprights 34 as explained below. For this purpose, each end portion of the horizontal uprights 32 may comprise at least one connector 36 as described above, but extending substantially parallel to the third direction Z.

[0066] The supporting structure 30 comprises at least three vertical uprights 34 and in the In this case, it comprises four. The vertical uprights 34 carry the upper frame of the supporting structure, as visible in Figures 1 to 3. Each vertical upright 34 is arranged opposite another vertical upright 34 in the first direction X, and opposite another vertical upright 34 in the second direction Y.

[0067] Each vertical upright 34 comprises a first end portion 34a and a second end portion 34b opposite each other.

[0068] The first end portion 34a is placed on a lower zone, relative to the third direction Z, of the respective vertical upright 34. The first end portion 34a thus forms a foot of each vertical upright 34. As can be seen in FIGS. 1 to 3, each foot 34a is provided with a rolling element 42 and a lifting element 44 for the supporting structure. The rolling element 42 is for example a wheel making it possible to move the supporting structure along the XY plane. Advantageously, the wheel 42 comprises a stopping brake which blocks the movement of the wheel, and therefore, the movement of the supporting structure in the XY plane, when it is actuated. The lifting element 44 is for example a jack making it possible to move the supporting structure substantially along the third direction Z. The supporting structure 30 is thus movable in the three perpendicular directions of space X, Y, Z.The lifting element 44 is configured to be able to lift the supporting structure 30 continuously from a first low position or minimum height position to a second high position or maximum height position. The continuous height movement of the supporting structure makes it possible to achieve precise coaxial adjustment of the C axis with the XY plane containing the B axis.

[0069] In another configuration, the supporting structure 30 may comprise means for synchronously lifting all the vertical uprights 34 so as to allow the simultaneous lifting of all the feet 34a together and by a single command.

[0070] The second end portion 34b is adapted to be connected to at least two horizontal uprights. More precisely, the second end portion 34b is adapted to be connected to the end portions of at least two horizontal uprights. For this purpose, each second end portion 34b of the vertical uprights 34 comprises one or more connectors 36 similar to that described previously, and / or one or more bores (not visible). In the non-limiting example of the figures, the second end portion 34b of each vertical upright 34 comprises a bore (not visible), a connector 36 extending substantially in the first direction X and a connector 36 extending substantially in the second direction Y.

[0071] In this configuration, to connect one of the vertical uprights 34 to one of the horizontal uprights 32, the vertical upright 34 is placed between the assembly tabs of the connector 36 of the respective horizontal upright which extends substantially parallel to the horizontal upright 32. in the Z direction. The vertical post 34 is in particular placed between the assembly tabs of this connector 36 so as to align the holes of the assembly tabs and the bore passing through the vertical post. A removable connecting element 38 similar to that used to connect two horizontal posts can then be arranged so as to pass through the two holes of the connector and the bore of the vertical post. The vertical post 34 and the horizontal post 32 are thus connected to each other and held in position relative to each other.

[0072] The supporting structure 30 may further comprise a plurality of connecting bars 46. Each connecting bar 46 may be arranged between each free connector 36 arranged on the second end portion of the vertical upright 34 and one of the free connectors 36 arranged on the end portions of the horizontal uprights 32. By “free connector” is meant a connector that has not yet been used to connect two uprights together. As visible in Figures 1 to 3, each connecting bar 46 extends substantially diagonally between one of the vertical uprights 34 and one of the horizontal uprights 32. The connecting bar 46 comprises two ends, each advantageously comprising a hole (not visible in the figures) which makes it possible to connect the connecting bar 46 to the connectors 36 of the vertical upright 34 and horizontal upright 32 that it connects.In particular, a removable connecting element 38 similar to that used to connect two horizontal uprights will be used to connect each connecting bar between the respective vertical 34 and horizontal 32 uprights.

[0073] The supporting structure 30 may further comprise a plurality of winches. Each winch 48 may be arranged between a vertical upright 34 and a horizontal upright 36. Preferably, all the winches 48 extend along the same plane, in particular the XZ plane or the YZ plane. In other words, each winch 48 is arranged between each of the vertical uprights 34 and only each of the horizontal uprights 36 extends substantially parallel to a single direction. For example, in Figures 1 to 3, four winches are installed, each winch connecting the second end portion 34b of the respective vertical upright 34 and one of the end portions of the horizontal uprights 32 extending substantially parallel to the first direction X. All the winches 48 therefore extend along the YZ plane in the example of Figures 1 to 3.On the contrary, in these figures, no winch 48 is installed between the respective vertical upright 34 and the horizontal uprights 32 extending substantially along the second direction Y. No winch 48 therefore extends along the plane XZ in the example of figures 1 to 3.

[0074] The winch 48 makes it possible to give the respective vertical upright 34 a rotational movement around the direction of extension of the horizontal upright 32 to which the winch 48 connects it.

[0075] The supporting structure 30 further comprises a rail 50. The rail is connected to the frame upper 40, in particular to two horizontal uprights 32 arranged opposite each other. For example, in Figures 1 to 3 the rail 50 is connected to the horizontal uprights 32 which extend substantially in the Y direction so that the rail 50 extends substantially parallel to the X direction. The rail 50 comprises a first end portion 50a and a second end portion 50b opposite each other. Each of the first and second end portions 50a, 50b is provided with a locking element 52 of the rail 50 movable between a locking position and an unlocking position of the rail 50. The first end portion 50a of the rail further comprises a first hole 51a for fixing a marker which will be described later. The second end portion 50b of the rail comprises a second hole 51b for fixing the marker.

[0076] The rail advantageously has an H shape. Thanks to the H shape, a carriage 54 can be installed in the rail 50. The carriage 54 is mounted to be movable in translation in the direction of extension of the rail 50, in this case the direction substantially perpendicular to the direction X.

[0077] The carriage is preferably a hoist-carrying carriage 54. A hoist 56 can thus be connected to the rail 50 via the carriage 54. The hoist 56 will then be integral with the movements of the carriage 54 along the rail.

[0078] The hoist 56 comprises a chain (not shown) movable substantially in the Z direction between a low position and a high position. This allows, as will be detailed later, the axle which will be mounted in the bore of the bogie to move from the ground to an alignment position between the axis B of the bore 14 and the axis C of the axle.

[0079] One end of the chain of the hoist 56 is connected to a hooking device 57, visible in particular in [Fig.7].

[0080] As will be explained below, the rail 50, the carriage 54 and the hoist 56 constitute means for moving the axle 12 into a position of insertion into the bore 14 of the bogie 16 and of mounting the axle 12 in the bore 14 of the bogie.

[0081] The installation further comprises a contact arm 58 with the bogie. As particularly visible in [Fig. 3], the contact arm extends in an L shape from one of the vertical uprights 54 of the supporting structure 30. On a first part 58a of the L shape, the contact arm 58 extends substantially parallel to the Y direction, and is substantially aligned in the X direction with the horizontal upright 32 located in contact with the first end part 50a of the rail 50. On a second part 58b of the L, the contact arm 58 projects relative to the supporting structure substantially parallel to the Y direction. Advantageously, the second part 58b of the L is located laterally relative to the rail 50, which prevents the contact arm 58 from interfering with the movement of the axle during its installation in the bore 14 of the bogie.

[0082] As can be seen in particular in the detail of the enlargement of [Fig.3], the second part 58b of the L is connected to a support block 58c of the bogie. The support block 58c extends substantially parallel to the third direction Z. Advantageously, the support block 58c comprises a substantially concave support face 58d against which the bogie 16 comes into contact. The support block 58c may further comprise a strap 58e. The strap 58e is for example arranged adjacent to the support face 58d. The strap 58e makes it possible to fix the bogie to the support block so as to limit the relative movements between the bogie 16 and the supporting structure 30 during the mounting of the axle 12 in the bore 14.

[0083] The installation 10 further comprises means for aligning the axis B of the bore of the bogie with the axle axis C. These alignment means may comprise a mark 110, visible in FIGS. 1 to 3, and a laser beam device 120, visible in [Fig.8],

[0084] The mark 110 is arranged on a face of a target 112 carried by the supporting structure. In particular, the target is suspended from one of the holes 51a, 51b provided in the first end portion 50a and the second end portion 50b of the rail 50. In particular, the target 112 is connected to one of the holes 51a, 51b of the first and second end portions of the rail from a suspension element 114. Advantageously, a length of the suspension element 114 is chosen so that the mark 110 and the axis C of the axle 12 are aligned in the Z direction when the axle 12 is carried by the hoist 56 and the chain of the hoist 56 is in the high position.

[0085] The reference mark 110 has for example a cross shape with a first line substantially parallel to the Z direction and a second line substantially parallel to the X direction when the target 112 is suspended from the rail.

[0086] The laser beam device 120 is a device emitting a laser beam. The laser beam device 120 is shaped to be installed in the bore of the bogie. More specifically, the laser beam device 120 is shaped so that, when installed in the bore, the axis of the laser beam is coaxial with the axis B of the bore 14 of the bogie.

[0087] Advantageously, the laser beam has the same shape as the reference mark 110. For example, the laser beam has a cross shape with a first ray substantially parallel to the Z direction and a second ray substantially parallel to the X direction when the laser beam device 120 is installed in the bore 14.

[0088] As visible in [Fig.8], the laser beam device 120 comprises a bore 122 located in a substantially central position of the laser beam device 120 in the Y direction. This bore 122 receives, when the laser beam device 120 is installed in a final position in the bore, a rod 130 for holding in position.

[0089] In order to identify the final position of the laser in the bore, the installation may further comprise a guide tool 140 visible in [Fig.8]. The guide device is configured to be disposed on the open end 20 of the bogie 16 which communicates with the bore 14 in which the axle 12 will be installed. The guide device comprises a hole 142 having a shape and dimension substantially equal to those of the bore 122 of the laser beam device 120. When the laser beam device 120 is in its final position in the bore 14, the hole 142 of the guide tool 140 and the bore 122 of the laser beam device are aligned. The position-holding rod 130 can then be inserted into the bore 122 of the laser beam device 120 through the hole 142 of the guide tool 140.

[0090] As seen in [Fig.9], the guide tool 140 also serves to identify a final position of the axle 12 in the bore 14, similar to the identification of the final position of the laser beam device. In particular, the hole 142 of the guide tool 140 is substantially equal in shape and size to the third bore 26 of the axle 12. When the axle 12 is in its final position in the bore 14, the hole 142 of the guide tool 140 and the third bore 26 of the axle are aligned.

[0091] The position-holding rod 130 also serves to hold the axle 12 in its final position in the bore 14. In particular, when the hole 142 of the guide tool 140 and the third bore 26 of the axle are aligned, the position-holding rod 130 can be inserted into the bore 26 of the axle 12 through the hole 142 of the guide tool 140.

[0092] The installation may further comprise an axle support 60, shown in [Fig.4]. Advantageously, the axle support 60 is made of metal, for example stainless steel for its thermal and mechanical properties.

[0093] The axle support 60 comprises two half-collars 62, a collar support 64 and a balance bar 66. Each of these parts of the axle support 60 will be described in the following with respect to the position that it adopts in [Fig.4] according to the orthonormal reference frame formed by the directions X, Y and Z. It should be noted, however, that the axle support 60 is advantageously removable, these parts being advantageously separable from one another. Thus, in a dismantled position of the axle support, not illustrated, these parts of the axle support are isolated from one another, and can adopt any position in space.

[0094] The two half-collars 62 are preferably identical. The same references will therefore be used to describe the same parts of the two half-collars.

[0095] Each half-collar consists of a block comprising a front face 62a, a rear face 62b (visible in [Fig.2]), a first lateral face 62c and a second lateral face 62d (visible in [Fig.2]). The front face 62a and the rear face 62b are opposite and substantially parallel to each other. In [Fig.4], the front faces 62a and rear 62b extend substantially parallel to the XZ plane. Preferably, the front 62a and rear 62b faces are identical. The side faces 62c, 62d are opposite and substantially parallel to each other. In [Fig.4], the side faces extend substantially parallel to the YZ plane. Preferably, the two side faces 62c, 62d are identical.

[0096] Each lateral face 62c, 62d makes it possible to connect the front face 62a and the rear face 62b of each half-collar 62. Advantageously, a shoulder (not visible in the figures) exists between the front face 62a and each lateral face 62c, 62d, as well as between the rear face 62b and each lateral face of the half-collar 62c, 62d. Each shoulder makes it possible to fit each half-collar 62 into the collar support 64, as will be explained later.

[0097] Each half-collar 62 further comprises a flat face 62e and a concave face 62f. The flat face 62e and the concave face 62f connect the front 62a and rear 62b faces of each half-collar 62. Advantageously, the flat 62e and concave 62f faces are substantially perpendicular to the lateral faces 62c, 62d of the respective half-collar 62.

[0098] The flat face 62e is substantially rectangular and opposite the concave face 62f. The concave face 62f has a concavity. Two substantially flat edges 62g extend on the concave face 62f between each end of the concavity and the respective lateral face 62c, 62d of the half-collar.

[0099] The substantially flat edges allow the two half-collars 62 to be stacked, so that their concavities face each other. In particular, to stack the two half-collars 62, the substantially flat edges 62g of the concave face 62f of one of the half-collars 62 are brought into contact with the substantially flat edges 62g of the concave face 62f of the other half-collar 62. The two half-collars 62 thus form a collar crossed by an orifice 63 for receiving the axle 12. As can be seen from [Fig. 4], this orifice 63 for receiving the axle 12 is delimited by the concavities of the two half-collars. Advantageously, a shape and a dimension of the orifice 63 for receiving the axle 12 are substantially equal to the cross-section of the central part 12d of the axle 12. The axle 12 can thus be kept blocked between the two half-collars 62 as will be detailed.

[0100] The collar support 64 comprises a support surface 64a and four connecting segments 64b.

[0101] The support surface 64a is flat. In [Fig.4], the support surface extends substantially parallel to the XY plane. The support surface comprises an upper face 64aa and a lower face 64ab. The upper face 64aa comprises a support zone (not visible) and a peripheral zone 65.

[0102] The support zone has a shape and a dimension substantially equal to the flat face of one of the half-collars 62. The support zone is thus intended to receive the face in support plate 62e of one of the half-collars 62. The peripheral zone 65 surrounds the support zone. The peripheral zone 65 preferably has a substantially rectangular loop shape.

[0103] The support surface 64a is configured to support the collar formed by the two half-collars 62 as indicated previously.

[0104] Each connecting segment 64b has a substantially flat shape comprising an outer face 64ba, an inner face 64bb and two lateral edges 64bc. Each connecting segment 64b extends substantially perpendicular to the support surface 64a. In this case, each connecting segment 64b extends substantially parallel to the third direction Z.

[0105] As visible in [Fig.4], the four connecting segments 64b are arranged on the peripheral zone 65 of the support surface 64a. The connecting segments 64b are advantageously facing each other two by two in the first direction X. The connecting segments are advantageously facing each other two by two also in the second direction Y. Preferably, the connecting segments 64b are separated from each other in the direction X or in the direction Y by distances which allow one of the lateral edges 64bc and the internal face 64bb of each connecting segment 64b to be in contact with one of the shoulders arranged between the lateral faces 62c, 62d and the front face 62a or rear face 62b of each half-collar 62.Each half-collar 62 is thus fitted into the axle support 60 between the four connecting segments 64b, which prevents the collar from moving in the first direction X and in the second direction Y when the collar is installed on the support surface 64a.

[0106] An end portion of each connecting segment opposite the support surface is crossed by a hole (not visible in the figures). Advantageously, the holes of the connecting segments 64b arranged opposite each other in the direction X are aligned with each other. These holes make it possible to connect the collar support 64 and the spreader bar 66 as will be detailed below.

[0107] The rudder 66 comprises a front portion 66a and a rear portion 66b.

[0108] The front part 66a comprises a first arm 68 and two plates 70. The first arm 68 extends substantially in the X direction. In the non-limiting example of [Fig. 4], the plates 70 are separated from each other in the Y direction by a distance substantially less than the distance which separates two connecting segments 64b in the Y direction. Thus, the two plates 70 can be arranged between the 4 connecting segments 64b. Each plate comprises two holes (not visible in the figures) which are arranged opposite each other in the Y direction to the holes passing through the connecting segments 64b when the plates are arranged between these segments 64b. Thus, a rod 72 can pass through the holes of the two plates 70 and of two segments 64b arranged opposite each other in the Y direction. Each rod 72 therefore makes it possible to connect the collar support 64 and the rudder 66.

[0109] The rear part 66b of the spreader bar comprises an arm 74, a push bar 76 and an end portion 78. The arm 74 and the push bar 76 extend substantially in the X direction, while the end portion 78 extends substantially in the Z direction. The end portion 78 is connected to a guide cylinder 80 arranged substantially opposite in the Z direction of the push bar 76 and extending substantially in the Y direction.

[0110] The front 66a and rear 66b parts of the spreader bar 66 are connected to each other by a crosspiece 82 which extends substantially in the Y direction. The crosspiece 82 comprises, on one end near the front part 66a of the spreader bar, a part 83 extending substantially in the Z direction and comprising an orifice 84. The orifice 84 allows the attachment of the attachment device 57 of the hoist. The axle support 60 can thus be moved in the Z direction thanks to the movement of the chain of the hoist 56, and in translation in the direction of extension of the rail 50 when the hoist 56 follows the movement of the carriage 54. On another end near the rear part 66b of the spreader 66, the crosspiece 82 is crossed by a through hole (not visible in the figures) which passes substantially in the Z direction through the crosspiece 82. As visible in [Fig.4], this through hole is adapted to receive a rod 86.

[0111] As particularly visible in Figures 6 and 7, when the axle 12 is received in the orifice 63 of the collar formed by the two half-collars 62, the axle is arranged so that the guide cylinder 80 is introduced into the cavity 22 of the axle 12 and the rod 86 is introduced into the second bore arranged on the second end portion 12e of the axle 12. This arrangement makes it possible, on the one hand, to maintain the axle in position in the axle support 60, and on the other hand, to guarantee that the axle 12 is oriented in a position which ensures that when the axle 12 arrives in its final position in the bore 14, the bore 26 and the hole of the guide tool are aligned and face each other.

[0112] The installation 10 further comprises a tank 90 shown in FIGS. 1, 5, 6 and 7. The tank 90 comprises a tank 92 and a plurality of substantially vertical uprights 94.

[0113] The tank 92 has for example a rectangular parallelepiped shape, but other shapes are conceivable. In the figures, the tank 92 is delimited by two longitudinal walls 92a, two transverse walls 92b, a lower wall 92c and an upper wall 92d. The longitudinal walls 92a extend along two planes substantially parallel to each other and along the YZ plane. The transverse walls 92b extend along two planes substantially parallel to each other and along the XZ plane. The lower 92c and upper 92d walls extend along two planes substantially parallel to each other and along the XY plane.

[0114] As is apparent from Figures 6 and 7, an interior 95 of the tank 92 is hollow. The interior of the tank 94 advantageously has a length and a width greater than, respectively, the length and the width of the axle 12, which allows, as will be detailed, to introduce the axle into the tank 90.

[0115] Each longitudinal wall has a thickness that defines a longitudinal edge 96 of the tank. Similarly, each transverse wall has a thickness that defines a transverse edge 98 of the tank.

[0116] As clearly shown in [Fig. 6], the arms 68, 74 of the spreader bar, as well as the push bar 76 have a length greater than the width of the tank 92. Thus, the arms 68, 74 and the push bar 76 rest on the longitudinal edges 96 of the tank 92 when the axle 12 and the axle support 60 are arranged in the tank. This prevents the axle support 60 from touching the bottom of the tank 92 when it is arranged inside the tank 92.

[0117] As clearly shown in [Fig.5], the upper wall 92d of the tank comprises a plurality of removable covers 99, so as to define an open position and a closed position of the tank 92. In the closed position, the covers 99 are arranged on the tank, so as to prevent access to the interior 95 of the tank 92. In the open position, all the covers 99 are removed from the tank 92, which allows access to its interior 95.

[0118] Advantageously, one or more of the covers 99 a / have a shape adapted to the passage of the axle support 60, in particular the arms 68, 74 and the push bar 76, when the axle 12 is introduced into the tank. These covers, the shape of which allows the passage of the axle support 60, make it possible to define a third position of the tank 92, called the axle cooling position. In the cooling position of the axle 12, all the covers 99 are arranged on the tank 92, with the exception of the covers whose shape allows the passage of the axle support 60. This makes it possible to close the tank 92 as much as possible when the axle 12 is inside, while allowing the arms 68, 74 and the push bar 76 to rest on the longitudinal edges 96 of the tank 92, so as to limit heat transfers to the outside.

[0119] The tank 92 is intended to be filled with liquid nitrogen in the axle cooling position.

[0120] The tank 92 is supported by the plurality of substantially vertical uprights 94. These uprights extend substantially parallel to the Z direction from the lower face 92d of the tank. In the figures, the tank 90 comprises four substantially vertical uprights 94 placed under each intersection between the longitudinal and transverse walls. Of course, the tank 90 could comprise more than four uprights.

[0121] Advantageously, each vertical upright comprises a foot provided with an element of rolling 97, like a wheel. The wheel 97 allows the tray 90 to be moved in the XY plane. The tray can thus be easily placed under the supporting structure 30, as seen in [Fig.l].

[0122] The invention further relates to a method for mounting the axle 12 in the bogie 16 using the installation of [Fig.l]. In the following, we will in particular describe the method for mounting the axle in one of the axis bores B of the bogie. In the following, a direction along the axis B of the bore will be referred to as the "axle installation direction".

[0123] The method firstly comprises providing the mobile supporting structure 30.

[0124] In certain cases, the supporting structure 30 will already be mounted and it will only be necessary to move it along the XY plane until the bearing face 58d which is connected to the contact arm 59 of the supporting structure 30 comes into contact with the bogie 16 installed in the landing gear 18. The strap 58e of the support block 58c will then be arranged around the bogie 16 to block the relative movements of the supporting structure 30 with respect to the bogie 16.

[0125] In other cases, the supporting structure 30 is not mounted beforehand. A non-limiting example of a method for mounting the supporting structure comprises firstly mounting the upper frame 40 from the connection of the horizontal uprights 32 as explained previously, then connecting the vertical uprights 34 to the upper frame 40 as also explained previously. At this stage, the vertical uprights 34 may be arranged substantially parallel to the horizontal plane XY. This avoids having to use means for supporting the upper frame 40 at a sufficient height to be able to connect the vertical uprights 34 directly in their final position substantially parallel to the Z direction. The rail 50 may also be connected to the upper frame 40 as already explained.

[0126] In order to place the vertical uprights 34 substantially parallel to the third direction Z, the winches 48 will be mounted between the vertical uprights 34 and only the horizontal uprights 32 substantially parallel to a single direction, as shown below. The actuation of each winch 48 imparts a rotational movement to the respective vertical upright 34 about the direction of extension of the horizontal upright 32 to which this vertical upright 34 is connected by the winch. This makes it possible to easily move the vertical uprights 34 from the position substantially parallel to the XY plane to the position substantially parallel to the third direction Z.

[0127] Advantageously, before actuating the winches 48 to position the vertical uprights 34 in their final position, the movements in the XY plane of the wheels 42 belonging to two vertical uprights 34 located on a first side of the supporting structure 30 relative to the rail 50 are blocked. To do this, the wheel stop brake 42 belonging to two vertical uprights 34 located on said first side of the supporting structure 30 is actuated.

[0128] Following the locking of the wheels 42 of the vertical uprights 34 located on the first side of the supporting structure relative to the rail 50, the winches 48 associated with the two vertical uprights 34 located on a second side of the supporting structure 30 relative to the rail 50 can be actuated. Said second side is opposite said first side of the supporting structure 30. The actuation of the stopping brake of the wheels 42 on the first side of the supporting structure prevents the actuation of the winches 48 associated with the two vertical uprights 34 located on the second side of the supporting structure from causing a translation of the entire supporting structure 30 in the XY plane. The winches 48 associated with the two vertical uprights 34 located on the second side of the supporting structure 30 will be actuated until the vertical uprights 34 of said second side of the supporting structure 30 adopt their final position along the Z direction.

[0129] Once the vertical uprights 34 located on the second side of the supporting structure are placed in their final position substantially parallel to the Z direction, the connecting bars 46 connecting the horizontal uprights 32 and the vertical uprights 34 located on the second side of the supporting structure 30 can be installed.

[0130] After unlocking the movement of the wheels 42 associated with the vertical uprights 34 on the first side of the supporting structure, the steps of actuating the stopping brakes, actuating the winches and installing the connecting bars can then be carried out on the opposite sides of the supporting structure 30 relative to the rail 50. This makes it possible to place the vertical uprights 34 located on the first side of the supporting structure in the final position along the Z direction.

[0131] Once all the vertical uprights 34 are placed in the position substantially parallel to the Z direction, the levers 44 can be installed on each foot of the vertical uprights 34. Similarly, the contact arm 58 with the bogie can be connected to the respective vertical upright 34.

[0132] In order to complete the assembly of the supporting structure, the carriage 54 and the hoist 56 must be installed. To install the carriage 56 in the rail at least one of the locking elements 52 of the rail 50 must be moved into the unlocked position. This allows the carriage 56 to be inserted into the rail. Once the carriage 54 is inserted into the rail 50, the locking element 52 must be placed again in the locking position of the rail 50 in order to prevent the carriage 54 from leaving the rail 50 during its translation in the direction of extension of the rail. The hoist 56 is suspended from the carriage.

[0133] After all these steps, the supporting structure 30 will be in its mounted position and can be moved along the XY plane until the bearing face 58d which is connected to the contact arm 58 of the supporting structure comes into contact with the installed bogie 16. in landing gear 18.

[0134] The method further comprises a step of installing the axle on the axle moving means. As indicated previously, the axle moving means comprise the rail 50, the trolley 52 and the hoist 54.

[0135] In a first step, the step of installing the axle 12 on the axle movement means 12 makes it possible to position the axle 12 on the axle support 60. In particular, the hooking device 57 of the hoist is connected to the axle, which is moved suspended from the hoist 56 until it is installed on one of the half-collars 62 already arranged on the support surface 64a of the axle support 64.

[0136] The other half-collar 64 and the lever 66 can then be installed so as to block the axle 12 in the orifice 63, in accordance with the configuration described above with reference to FIGS. 4 and 6. In particular, when the axle 12 is received in the orifice 63 of the collar formed by the two half-collars 62, the axle 12 is arranged so that the guide cylinder 80 is introduced into the cavity 22 of the axle 12 and the rod 86 is introduced into the second bore arranged on the second end portion 12e of the axle 12. As indicated previously and clearly visible in [Fig. 7], the axle 12 will be blocked in the orifice 63 by its central portion 12d.

[0137] Once the axle support 60 is correctly installed around the axle 12, the hooking device 57 of the hoist 56 is hooked to the orifice 84 arranged near the front part 66a of the spreader bar 66 of the axle support 60. Then, the chain of the hoist 56 is gradually moved from its low position to its high position. The configuration of the axle support ensures that the assembly formed by the axle and the axle support is held by its center of gravity, which makes it possible to maintain the axle 12 in a position substantially parallel to the horizontal plane XY during its movement by the axle movement means.

[0138] Moving the hoist chain to the high position allows the axis C of the axle and the axis B of the bore to be aligned, so that the axle extends in the direction of installation of the axle.

[0139] The alignment of the axes B and C of the bore 14 and the axle 12 can be achieved by means of the laser beam device and the reference mark. In particular, as explained above, the laser beam device 120 is installed in the bore 14 of the bogie so that the axis B of the bore 14 is aligned with the laser beam emitted by the laser beam device 120. As indicated above, when installing the laser beam device 120 in the bore 14, the guide tool 140 can be used to detect the final position of the laser beam device 120 in the bore 14, and the rod 130 can be used to lock the laser beam device 120 in this final position.

[0140] Furthermore, as also indicated previously, the chain of the hoist 56 is configured so that in the high position, the axis C of the axle is necessarily aligned with the mark 110. Also, in order to guarantee that the axis C of the axle and the axis B of the bore are aligned, the method may comprise a step of aligning the laser beam and the mark 110. For this purpose, the mark 110 is initially carried by the hole 51a of the first end portion 50a of the rail. The supporting structure 30 is then moved in the Y direction thanks to the rolling elements 42, and in the Z direction thanks to the lifting elements 44, until the laser beam and the mark 110 are coincident. If the mark 110 and the emitted laser beam have a cross shape, the laser beam and the mark 110 are coincident when the vertical line of the mark 110 and the vertical ray of the laser beam are aligned, and when the horizontal line of the mark 110 and the horizontal ray of the laser beam are aligned.After this first alignment between the vertical line and ray, and between the horizontal line and ray, the mark 110 is removed from the hole 51a of the first end part 50a of the rail 50 and carried by the hole 51b of the second end part 50b of the rail. If in this position the laser beam and the mark are not coincident, the supporting structure is again moved in the Y direction and in the Z direction until they are coincident, as explained above.

[0141] The laser beam being aligned with the axis B of the bore 14, the alignment between the laser beam and the mark 110 implies that the axis B and the mark 110 are also aligned. The mark 110 is then arranged in a vertical plane comprising the installation direction of the axle 12. Since the mark 110 and the hoist are carried by the rail 50, the vertical plane comprising the installation direction of the axle as well as the mark 110 also corresponds to a lifting plane of the axis C of the axle 12.

[0142] It is noted that the reference mark 110 is mounted fixed relative to the rail. In other words, during movements of the supporting structure in the Y direction and in the Z direction, the relative position of the reference mark 110 relative to the rail does not change. Indeed, the reference mark 110 and the rail 50 are moved integrally with the supporting structure 30. The rolling elements 42 and the lifting elements 44 therefore constitute not only means for moving the supporting structure 30, but also means for moving the reference mark 110.

[0143] Once the axis C of the axle and the axis B of the bore 14 are aligned, the method comprises the introduction of the axle 12 into the bore 14 of the bogie, as visible in [Fig.9]. In particular, to introduce the axle into the bore, the hoist is connected to the axle support 60, in particular to the orifice 84 as indicated previously. The carriage 54 then moves in the direction of installation of the axle, which causes the movement of the hoist 56 and the axle 12 in this same direction. The carriage 54 and the hoist 56 are in particular moved in the direction of installation of the axle 12 until the final position of the axle 12 in the bogie 16 is identified by means of the guide tool 140 as previously described. Once in the final position, the axle 12 is fixed in the bore by means of the holding rod 130.

[0144] In order to improve the fixing of the axle in the bore, a thermal difference assembly can also be used. For this purpose, as visible in [Fig.6], the axle-axle support assembly is introduced into the tank 92 of the container 90. In particular, the axle 12 is introduced into the tank 92 in a horizontal position, that is to say, along the XY plane. The tank 92 is then placed in its axle cooling position. As indicated below, in the axle cooling position all the covers 99 are arranged on the tank 92, with the exception of the covers whose shape allows the passage of the axle support 60. The tank 92 is then filled with liquid nitrogen. Liquid nitrogen allows the axle to be cooled to approximately -200°C, which causes the axle 12 to shrink. In order to reach such a temperature, the axle is kept in the tank 90 filled with liquid nitrogen for, for example, 1 hour.When the axle is extracted from the tray 90, the retraction caused by the low temperatures facilitates the introduction of the axle into the bore 14. Once in the bore 14, the temperature of the axle increases, which causes an expansion of the axle which leads to an increase in its external diameter until it locks by self-tightening at room temperature in the bore.

[0145] To improve the mounting by thermal difference, the bore 14 of the bogie can be heated to a given temperature, for example +100°C. This causes an expansion of the bore. The introduction of the axle 12 into the bore 14 is thus facilitated. Once in the bore, the temperature of the bore 14 decreases to ambient temperature, which causes a retraction of the bore which makes it possible to increase the tightening of the axle in the bore 14.

[0146] To heat the bore 14, heating means, such as for example a resistor (not shown), may be placed in the bore 14. Optionally, a temperature sensor (not shown) may also be introduced into the bore 14 to control its heating.

[0147] Advantageously, before introducing the axle 12 into the bore 14, a sleeve 150, visible in FIGS. 1 and 9, is arranged around the end of the axle 12 which is arranged opposite the bore 14 in the direction of installation of the axle, in this case the first end 12a of the axle. In other words, the sleeve 150 is arranged around the end portion of the axle 12 which passes completely through the bore 14 in order to place the axle 12 in its final position in the bore 14. The sleeve 150 makes it possible on the one hand to avoid direct collisions between the axle 12 and the bore 14, and on the other hand, to limit the loss of alignment of the axis C of the axle and the axis B of the bore which can be encouraged by the difference in section between the first end portion 12c and the central portion 12d of the axle. The sleeve 150 is advantageously removed after installation of the axle 12 in the bore 14.

[0148] As shown in [Fig.7], when the axle 12 is inserted into the tank 90 filled with liquid nitrogen, the sleeve 150 can be installed around the first end of the axle 12 after the axle 12 is extracted from the tank 90.

Claims

Claims

1. A method of mounting an axle (12) in a bore (14) of a bogie (16) mounted on a landing gear (18) of an aircraft, the landing gear (18) being in a deployed position, the bore (14) extending in a substantially horizontal direction, called the axle installation direction, between a first open end (14a) and a second open end (14b), the method comprising: a) providing a movable supporting structure (30) comprising means for moving the axle (12) movable in a direction substantially parallel to the axle installation direction, b) installing the axle (12) on the axle moving means, c) aligning the axis (C) of the axle (12) with the axis (B) of the bore (14), this step comprising: - positioning a mark (110) on the mobile supporting structure (30) and in such a way that the axis (B) of the bore (14) intercepts said reference mark (110),and - positioning the axle (12) so that its axis (C) is aligned in the installation direction with said mark (110), d) introduction of the axle (12) into said bore (14) of the bogie (16) by moving the means for moving the axle (12) in the direction substantially parallel to the installation direction of the axle.,

2. Method according to claim 1, comprising a step prior to step d) comprising the introduction of the axle (12) in a horizontal position, for a given time, for example one hour, in a tank (90) filled with liquid nitrogen.

3. Method according to one of claims 1 or 2, in which the mark (110) is arranged in a vertical plane comprising the installation direction, this plane corresponding to a lifting plane of the axis (C) of the axle (12).

4. A method according to any preceding claim, comprising mounting a laser beam device (120) in the bore (14) of the bogie such that the axis of the laser beam is coaxial with the axis (B) of the bore (14) of the bogie.

5. A method according to one of the preceding claims, wherein step d) is preceded by a step comprising mounting a sleeve (150) around a first end (12a) of the axle (12) which is arranged opposite the bore (14) of the bogie according to the direction of installation of the axle.

6. Installation for implementing a method of mounting an axle (12) in a bore (14) of a bogie (16) mounted on a landing gear (18) of an aircraft, the landing gear (18) being in a deployed position, the bore (14) extending in a substantially horizontal direction, called the axle installation direction, between a first open end (14a) and a second open end (14b), the installation comprising: - a movable supporting structure (30), - means for aligning the axis (B) of the bore of the bogie with the axis (C) of the axle, the alignment means comprising a mark (110) carried by the movable supporting structure (30), - means for moving the axle (12) into a position for insertion into the bore (14) of the bogie (16) and mounting the axle (12) in the bore (14) of the bogie.

7. Installation according to claim 6, further comprising a tank (90) filled with liquid nitrogen.

8. An installation according to claim 6 or 7, wherein the alignment means further comprises a laser beam device (120) shaped to be installed in the bore (14) of the bogie so that the axis of the laser beam is coaxial with the axis (B) of the bore (14) of the bogie.

9. Installation according to one of claims 6 to 8, further comprising means for moving the reference mark comprising at least one rolling element (42) configured to move the supporting structure (30) along a horizontal plane, and at least one lifting element (44) of the supporting structure (30) configured to move the supporting structure (30) in translation along a substantially vertical direction (Z).

10. Installation according to one of claims 6 to 9, in which the supporting structure (30) comprises an upper frame (40) carried by a plurality of vertical uprights (34), the upper frame (40) supporting the means for moving the axle into a position for insertion into the bore (14) of the bogie and for mounting the axle in the bore (14) of the bogie.

11. Installation according to claim 10, in which the displacement means comprise a rail (50) carried by the upper frame and a hoist (56) mounted for translational movement on the rail (50) according to the

12. axle installation direction. Installation according to claim 11, in which the marker (110) is fixedly mounted relative to the rail and arranged in a plane comprising the axle installation direction (12) and the translational movement direction of the hoist (56) on the rail.

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