DRIVE UNIT FOR AN AIRCRAFT HAVING LIFTING POINTS, AND CARRIAGES FOR SUPPORTING SUCH A UNIT

Abstract

A drive unit includes an engine such as a turbofan engine and a nacelle which includes, on the outside around an annular stream of fresh air, starting from upstream, an air inlet, front side covers, a thrust reverser having reversal gratings and movable rear covers. The front side covers surround the reversal gratings of the thrust reverser when it is closed, and the movable rear covers retreat with said gratings to open the reverser. The engine includes lifting points that form heavy-duty attachment points intended to receive handling clevis for lifting and transporting the drive unit. The lifting points are two upper lifting points arranged on the engine, each on one side of the engine radially behind the front side covers above the horizontal diameter (D) of the drive unit.

Claims

1. A drive unit comprising: a motor being a bypass turbojet engine; and a nacelle comprising outside around an annular flow path of fresh air, from upstream, an air inlet, lateral front cowls, a thrust reverser comprising thrust reverser cascades, and movable rear cowls, wherein: the lateral front cowls surrounds the thrust reverser cascades of the thrust reverser when the thrust reverser is closed, and the movable rear cowls moves back with the thrust reverser cascades to open the thrust reverser, the motor includes lifting points forming resistant hooking points intended to receive handling clevises allowing lifting and transporting the drive unit, wherein the lifting points includes two upper lifting points disposed on the motor, each on one side of the motor radially behind the lateral front cowls above a horizontal diameter of the drive unit, and each lateral front cowl includes a removable hatch that is movable between a closed position in which the removable hatch is flush with respective lateral front cowl and an open position in which the removable hatch opens an access to one of the two upper lifting points, each removable hatch is disposed radially outward of one of the two upper lifting points.

2. The drive unit according to claim 1, wherein the motor includes suspension points to a mast.

3. The drive unit according to claim 1 further comprising a handling clevis fastened on each upper lifting point when the removable hatches are open and the thrust reverser is open.

4. The drive unit according to claim 1, wherein each upper lifting point is disposed in a transverse plane inside an angular sector centered on an axis of the nacelle, the angular sector being comprised between 20 and 40 above the horizontal diameter of the nacelle.

5. The drive unit according to claim 1, wherein the nacelle includes a lower front cowl and the bypass turbojet engine includes two lower support points, each of the two lower support points is disposed radially behind the lower front cowl.

6. A carriage for a drive unit according to claim 1, configured to present, in a transverse direction, a total width less than a maximum width of the drive unit.

7. The carriage according to claim 6 further comprising, on each side, a hinged arm, wherein the hinged arm includes a lower portion connected by a pivot to a base of the carriage, and an upper portion including a bearing point which is fastened on one of the two upper lifting points.

8. The carriage according to claim 7, wherein the hinged arms are dissembable.

9. The carriage according to claim 6 further comprising, on each side, an upright disposed rearwardly of the lateral front cowls, and the upright is connected, in an upper portion, to one of the two upper lifting points.

10. The carriage according to claim 9, wherein each upright includes, rearward in a longitudinal direction, a strut bearing on a base of the carriage behind the upright.

11. The carriage according to claim 9, wherein each upright includes, forward in a longitudinal direction in the upper portion, arms extended forward and connected, at front ends thereof to one of the two upper lifting points.

12. The carriage according to claim 9, wherein the uprights are dissembable.

13. The carriage according to claim 6 further comprising an upstream transport transverse lower cross-member, wherein: the nacelle of the drive unit includes a lower front cowl and the bypass turbojet engine includes two lower support points, each of the two lower support points is disposed radially behind the lower front cowl, and the upstream transport transverse lower cross-member is fastened under the two lower support points of the motor.

14. The carriage according to claim 6 further comprising a plurality of bearing points and a connection, wherein: the nacelle of the drive unit includes a lower front cowl and the bypass turbojet engine includes two lower support points, each of the two lower support points is disposed radially behind the lower front cowl, the bearing points are for the two upper lifting points and for the two lower support points, and the connection is between the bearing points for the two upper lifting points and the bearing points for the two lower support points, wherein the connection takes up clearances due to differences in geometry between geometry of the motor and geometry of the carriage.

15. A motor transport assembly comprising the drive unit according to claim 1 and a carriage for the drive unit, wherein the carriage is configured to present, in a transverse direction, a total width less than a maximum width of the drive unit.

Description

DRAWINGS

[0043] In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

[0044] FIG. 1 is a cross-sectional diagram of a drive unit along a sectional plane passing through lifting and support points disposed behind front cowls according to the present disclosure;

[0045] FIGS. 2, 3, 4, and 5 show, in the same sectional plane, different steps of using a first type of carriage adapted for the drive unit;

[0046] FIGS. 6, 7, 8 and 9 show successively in side cross-section, in front view with a small inclination and in front view, a second type of carriage adapted for this drive unit; and

[0047] FIG. 10 shows, in cross-section, a variant of this second type of carriage not comprising a lower transport beam.

[0048] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

[0049] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0050] FIG. 1 shows a drive unit 1 having a nacelle 3 containing a bypass turbojet engine 4 supported by a mast 2 disposed at 12 o'clock.

[0051] To this end, the turbojet engine comprises suspension points 13 configured to receive suspension clevises 13 allowing fastening the turbojet engine to the mast 2.

[0052] Each side of the turbojet engine 4 is surrounded by a set of thrust reverser cascades 6, which in a closed position of the thrust reverser lies radially behind front cowls 8, 10 forming the aerodynamic outer surface of the nacelle 3.

[0053] The front cowls include, symmetrically relative to a vertical axis, lateral cowls 8 covering a large portion of the sides, a lower cowl 10, and an upper cowl 12 comprising an aerodynamic cowling in the extension of a suspension mast 2 fastened under an aircraft. The outer contour of the turbojet engine 4 comprises lifting points 14 and support points 16 firmly fixed to this turbojet engine to support its mass, and disposed respectively in the upper portion clearly above a horizontal diameter, in positions about 60 and 300, also called 2 o'clock and 10 o'clock positions, and in the lower portion in positions about 145 and 215, close to the 5 o'clock and 7 o'clock positions. These lifting points are distinct from the fastening points described above. The lifting points are distinguished by the fact that they are dimensioned to transmit loads lower than those of the suspension points. As will appear later in the description, these lifting points have a role during the static maintenance phase of the motor and as such the forces which will pass through these points are much lower than those which pass through the suspension points in the phase of using the drive unit.

[0054] By definition, and in a conventional manner per se, the lifting points 14 are capable of receiving handling clevises 24 (FIG. 2) allowing lifting and transporting the complete motorization with the nacelle 3 thereof. The handling clevises 24 in one form are inserts intended to be removed once the drive unit 1 is fastened to the suspension mast 2 at the suspension points 13.

[0055] Each lateral cowl 8 comprises in the upper portion a hatch 18 which is removable and movable between a closed position in which the hatch is flush with said cowl and an open position in which the hatch opens the access to an upper lifting point 14, disposed radially in front of an upper lifting point 14. The removable hatch is adapted to be completely removed from the lateral cowl 8. The lower support points 16 are disposed behind the lower cowl 10.

[0056] In this manner, by quickly opening the removable hatches 18, representing small elements which are easy to be stored, the upper lifting points 14 are accessed. In particular the lifting points 14 and the support points 16 represent resistant fasteners which can receive technical elements applying forces, such as cylinders for displacing the thrust reverser cascades 6, the removable hatches 18 which are oppositely disposed then facilitate maintenance work on these technical elements.

[0057] FIG. 2 shows after opening the hatches 18 without removing the lateral cowls 8, and opening the thrust reverser to move back the cascades 6 thereof in order to release the lifting points 14 located behind, the fastening of a handling clevis 24 on each lifting point 14. Similarly the lower cowl 10 is removed to fasten a lower transverse transport beam 26 on the two lower support points 16.

[0058] A lifting tackle 20 fastened to the mast 2 of the aircraft, includes on each side an arm 28 extending in the width, having one end coming above the handling clevis 24, to receive a suspension cable 22 fastened to this clevis.

[0059] FIG. 3 shows a transport carriage 30 including on each side a hinged arm 34 which pivots in a transverse plane thanks to a pivot 36 disposed at its base, having a longitudinal axis fastened on the side of the carriage.

[0060] The hinged arm 34 includes a lower portion connected by the pivot 36 to the base of the carriage 30, and an upper portion 32 including a bearing point 38 which is fastened on an upper lifting point 14.

[0061] By spreading out the two hinged arms 34, a space available is cleared between these arms for moving the carriage 30 forward and disposing it under the nacelle. Then the two arms 34 are brought closer towards the axis of the nacelle, to adjust on each side an upper anchoring point of this arm on the handling clevis 24, then to be fastened thereon using a quick locking system.

[0062] The lifting tackle 20 can then be detached from the handling clevises 24, in order to take the carriage 30 placed on displacement wheels, with the complete motorization system which has undergone a minimum of disassembly of the front cowls thereof.

[0063] FIG. 4 shows the handling carriage 30 then brought, supporting the drive unit, after the removal of the hinged arms 34 thereof by detaching the pivots 36 holding these arms on the carriage, which includes a minimum transverse space desirable for allowing it in particular to enter a minimum passage section 40. This passage section 40 may in particular represent the passage section of a cargo door of an aircraft, a container or a truck trailer.

[0064] During the displacement of the handling carriage 30, the hinged arms 34 are taken with it, in order to fasten them again on this carriage during subsequent operations.

[0065] It should be noted that the handling clevises 24 disposed clearly above the horizontal diameter D of the nacelle, in an angular sector centered on the axis of the nacelle, comprised between 20 and 40 above this diameter, in particular at an angle of 30, can project outside the contour of this nacelle without going beyond the total width thereof.

[0066] FIG. 5 shows that the removal of the lateral panels 8 of the nacelle is possible in order to perform maintenance operations behind these panels, which can be done with the hinged arms 34 remaining in place on the carriage 30, by spreading them out only, which reduces the disassembly operations.

[0067] The opening of the arms 34 is sufficient to allow spreading out the lateral panels 8 freeing them from the handling clevises 24, then displacing these panels upwards or in the longitudinal direction to take them out.

[0068] FIG. 7 shows a handling carriage 30 receiving a drive unit 1, which is placed on a displacement platform 48 equipped with wheels 50, and on the rear side indicated by the arrow AR of a drawbar 52.

[0069] FIGS. 6, 7, 8 and 9 show the handling carriage 30 comprising on each side a vertical upright 54 located behind the front cowls 8, at the movable rear cowls of the thrust reverser which are disassembled. At this level, the width of the nacelle is reduced, which allows having the vertical uprights 54 slightly behind the total external lateral space requirement of the nacelle given by the front cowls 8 remaining assembled.

[0070] Each vertical upright 54 is rigidly fastened to the base of the carriage 30, at the lower portion by a forward-facing triangular gusset 58, coming clearly below the horizontal diameter of the nacelle in order to remain within the lateral space requirement of these uprights, and at the upper portion by a strut 56 inclined backwards.

[0071] The two upper ends of the uprights 54 are connected by an upper cross-member 62 coming above the nacelle, which gives the lateral stability to these uprights.

[0072] At the upper portion, the front side of each vertical upright 54 includes two forward-facing arms 60, forming a longitudinally elongated triangle with the small base thereof fastened to this upright. The front end of the arms 60 receives a quick fastening of an upper handling clevis 24 installed on the turbojet engine. An upstream transverse lower cross-member 26 is fastened on the lower support points 16. The carriage also comprises a downstream transverse lower cross-member 27.

[0073] The significant stiffening in the longitudinal direction of the vertical uprights 54, thanks to the front gussets 58 and the rear struts 56, allows these uprights to withstand the heavy load of the drive unit applied in a cantilever manner to the front end of the arms 60.

[0074] Advantageously there is, on the carriage 30, in the chain of elements connecting the upper lifting points 14 to the lower support points 16, a connection allowing taking up clearances due to small differences in geometry between that of the turbojet engine and that of this carriage. In particular, slightly elastic elements, clearances or adjustment ranges can be provided.

[0075] As an option, the vertical uprights 54 can also be linked to the base of the carriage 30 by longitudinal pivots, such as the hinged arms 34 shown on the first type of carriage, or be removable.

[0076] FIG. 9 shows the minimum passage section 40 desired for the drive unit, which is equivalent to that given by the first type of carriage.

[0077] FIG. 10 alternatively shows a carriage 30 not using the lower transverse beam 26, which includes vertical uprights 54 sufficiently rigid to carry the front mass of the drive unit. With this carriage there is no need to provide a lower support point 16 on the turbojet engine.

[0078] Unless otherwise expressly indicated herein, all numerical values indicating mechanical/thermal properties, compositional percentages, dimensions and/or tolerances, or other characteristics are to be understood as modified by the word about or approximately in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice, material, manufacturing, and assembly tolerances, and testing capability.

[0079] As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean at least one of A, at least one of B, and at least one of C.

[0080] The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.