FR3146960A1 - Axial locking device for a first tubular element received for adjustment in a second tubular element - Google Patents

Abstract

Assembly comprising a first tubular element (20) intended to be received in a fit manner in a second tubular element (E), and an axial locking device (100) for the first element in the second element, the locking device comprising at least one obstacle (103) mounted to move radially through an opening (22) in the first element between a locking position in which the obstacle extends projecting from an external surface of the first element and a release position in which the obstacle extends set back from the external surface. Drive member, wheel, landing gear and aircraft implementing such an assembly. FIGURE OF THE ABSTRACT: Fig. 4

Description

Axial locking device for a first tubular element received for adjustment in a second tubular element

Climate change is a major concern for many legislative and regulatory bodies around the world. Indeed, various restrictions on carbon emissions have been, are being or will be adopted by various states. In particular, an ambitious standard applies both to new types of aircraft as well as those currently in circulation requiring the implementation of technological solutions in order to make them compliant with current regulations. Civil aviation has been mobilizing for several years now to make a contribution to the fight against climate change.

Technological research efforts have already made it possible to significantly improve the environmental performance of aircraft. All players in the sector are constantly working to improve energy efficiency. The Applicant takes into consideration the impact factors in all phases of design and development to obtain less energy-intensive, more environmentally friendly aeronautical components and products whose integration and use in civil aviation have moderate environmental impacts with the aim of improving the energy efficiency of air transport.

Consequently, the Applicant is constantly working to reduce its climate impact by using methods and operating virtuous development and manufacturing processes and minimizing greenhouse gas emissions to the minimum possible in order to reduce the environmental footprint of its activity.

This sustained research and development work covers new generations of aircraft engines, the weight reduction of aircraft, particularly through the materials used and the lighter on-board equipment, the development of the use of electrical technologies to provide propulsion, and, as an essential complement to technological progress, aeronautical biofuels.

To this end, the invention is the result of technological research aimed at very significantly improving the performance of aircraft and, in this sense, contributes to reducing the environmental impact of aircraft. For this purpose, the present invention relates to the field of mechanical assemblies and in particular to an axial locking device for a first tubular element received for adjustment in a second tubular element, and in particular a member for driving in rotation an aircraft wheel received for adjustment in a landing gear axle. The invention also relates to a member for driving in rotation an aircraft wheel equipped with such a locking device, a wheel equipped with such a drive member, a landing gear equipped with such a wheel, and an aircraft equipped with such a landing gear.

BACKGROUND OF THE INVENTION

In the field of aviation, it is now planned to equip aircraft with wheel rotation drive members to enable the aircraft to move on the ground without using its powertrains. A drive member mounted on a landing gear is described in document FR-A-3024706. This drive member comprises an electric motor mounted at one end of an axle carrying the wheels of the landing gear to transmit a rotational torque to one of said wheels via a connection interface.

The assembly of the electric motor, in particular the connection of the motor housing to the axle, and the supply of electrical energy to the motor are relatively complex in practice. The assembly means must be compact and the supply means must be protected. In fact, the electric motor is installed in a geometrically very constrained area of the landing gear and subject to external aggressions.

SUBJECT OF THE INVENTION

The invention therefore aims to propose a device allowing axial locking of two tubes inside each other which is relatively compact and little exposed to external attacks.

For this purpose, the invention proposes an assembly comprising a first tubular element intended to be received in a fit manner in a second tubular element, and a device for axially locking the first element in the second element, the locking device comprising at least one obstacle mounted to move radially through an opening in the first element between a locking position in which the obstacle extends projecting from an external surface of the first element and a release position in which the obstacle extends back from the external surface.

According to a particular characteristic, the obstacle is returned to the release position by elastic return means.

According to another particular characteristic, the locking device comprises a tubular body mounted axially movable in the first element between a retracted position and an advanced position, the body comprising a cam surface shaped to cooperate with a lower surface of the obstacle and bring the obstacle from the release position to the locking position when the body passes from the advanced position to the retracted position.

In particular, the body comprises an external annular groove having a truncated cone-shaped bottom, the bottom forming the cam surface.

In particular, the body comprises at least one cable passage conduit opening onto a front face of the body.

In particular, the cable passage conduit comprises at least one longitudinal slot opening onto the front face of the body, forming a notch.

The invention also relates to a drive member for rotating a wheel arranged to be pivotally mounted on an aircraft landing gear axle about an axis. The drive member comprises such an assembly, the first element being intended to be received in a fit manner in the axle.

The invention also relates to a wheel pivotally mounted on a shaft of an aircraft landing gear, the wheel being equipped with such a drive member.

The invention also relates to an aircraft landing gear comprising an axle on which such a wheel is rotatably mounted, the axle comprising an internal annular groove arranged to receive and cooperate with the obstacle of the locking device when the drive member is in the connected position in the axle and said obstacle in the locking position.

The invention further relates to an aircraft comprising at least one such landing gear.

The invention will be better understood in light of the following description, which is purely illustrative and not limiting, and must be read in conjunction with the appended drawings, among which:

there is a simplified representation of an aircraft comprising main landing gears comprising wheels provided with a rotation drive member according to the invention;

there is a front view of one of the main landing gears of the aircraft shown in ;

there is a perspective view of the axle and drive member fitted to the main landing gear illustrated in ;

there is a perspective view of the locking device, according to a particular embodiment of the invention, equipping the drive member illustrated in ;

there is an axial sectional view of the locking device illustrated in , in which the locking device is inactive;

there is a view identical to the , in which the locking device is in operation;

there is a detailed view of the locking device illustrated in .

DETAILED DESCRIPTION OF THE INVENTION

The invention is described here in application to an aircraft wheel but other applications are of course conceivable.

An aircraft A comprises, as illustrated in , two main landing gears P each comprising a leg J having a first end articulated on a structure S of the aircraft A and, opposite, a second end carrying wheels R, R _M rotating about an axis Y on a tubular shaft or axle E. The leg J is movable between a retracted position (not shown) and a deployed position illustrated here.

Each of the wheels R, R _M comprises a rim receiving a tire and is equipped with a brake. The rim is connected by a disc to a hub mounted to rotate on the axle E about the axis Y. In a manner known per se, the brake comprises a stack of disks received in an annular space delimited by the rim and the hub. The stack of disks comprises alternating stator disks fixed in rotation relative to the axle E and rotor disks fixed in rotation relative to the rim. Hydraulic or electromechanical actuators are arranged on an actuator-holder ring to exert a pressing force on the stack of disks. Each braking performed by the pilot of the aircraft A causes an increase in temperature of the brake disks and their immediate environment, requiring the provision of heat shields not detailed here. The brake is known per se and will not be detailed further here.

In reference to the , the leg J is held in the deployed position by means of a bracing member comprising a first connecting rod B1 articulated on the structure S of the aircraft A and a second connecting rod B2 articulated on the leg J and on the first connecting rod B1. The first connecting rod B1 and the second connecting rod B2 are, in the deployed position, in a substantially aligned position.

The leg J comprises a caisson C articulated on the structure S of the aircraft A, and a rod T slidably mounted in the caisson C along an axis Z to form a shock absorber. The rod T carries at a lower end the axle E pivotally receiving the wheels R, R _M . In a manner known per se, a main compass and a secondary compass (not shown here) allow the sliding of the rod T in the caisson C, while preventing the pivoting of the rod T about the axis Z, relative to the caisson C. The axle E is integral with the rod T so that said axle E is immobile with respect to said rod T. The axis Z is here substantially perpendicular to the axis Y. The landing gear will not be described in more detail here.

The R _M wheels are called "motorized", that is to say equipped with a drive member 1 intended to move the aircraft A without using the main powertrains of the aircraft when it is on the ground. The following description relates to one of the motorized R _M wheels which are here all identical but which could obviously be different.

In reference to the , the drive member 1 comprises a first element 10 of generally cylindrical shape and a second tubular element 20 extending coaxially projecting from the first element 10. The first element 10 and the second element 20 respectively constitute a motorization zone of the wheel R _M and a zone of engagement of the drive member 1 in the axle E.

The first element 10 comprises an electric motor 11 mounted at a free end of the axle E which is bordered by axial projections forming dog teeth E ₁ ( ).

The motor 11 has a stator 11.1 (visible on the ) carrying electromagnetic coils on the periphery. The stator 11.1 is coupled to the axle E by the engagement of the dog teeth E ₁ of said axle E in housings provided in said stator 11.1, so that the stator 11.1 is, along the Y axis, rotationally linked to the axle E.

The motor 11 also comprises a rotor mounted to rotate on the stator 11.1, here by means of bearings. The rotor comprises a drum carrying permanent magnets. The circulation, in the coils of the stator 11.1, of a current adapted to create a rotating magnetic field, induces on the drum a mechanical torque driving said drum in rotation. When the drive member 1 is in position on the axle E, the axis of rotation of the rotor coincides with the axis Y of rotation of the wheel R _M . The drum carries a plurality of tie rods 12 which extend parallel to the axis of rotation of the rotor. An interface member (not shown) extends between the tie rods 12 and the rim of the wheel R _M to connect in rotation the drum of the rotor and the rim so as to transmit the torque of said rotor to said wheel R _M .

The first element 10 also comprises an electric fan 13 mounted on the motor 11 to create an air flow around the brake discs and around the motor 11 so as to accelerate the cooling of said brake discs and said motor 11 as well as their immediate surroundings.

The second element 20 is integral with the stator 11.1 and is received in a fit manner in the axle E, said second element 20 extending here coaxially with respect to said axle E. A free end of the second element 20 carries a male electrical coupler 21 opening into a central orifice E ₂ formed in the axle E at the junction between the rod T and said axle E. The orifice E ₂ extends along an axis X perpendicular to the axis Y and to the axis Z and receives a female electrical coupler 30 adapted to receive the male electrical coupler 21 carried by the second element 20 of the drive member 1.

A guide system (not shown here) is provided on the female coupler 30 and on the second element 20 to ensure the correct alignment of the male coupler 21 and the female coupler 30 before their connection.

An angular keying system (not shown here) is also provided on the female coupler 30 and on the second element 20 to ensure the correct angular orientation of the male coupler 21 and the female coupler 30 before their connection. The keying system can also be provided on the axle E.

Electrical harnesses supply current to the motor of the drive member 1 and the brake cooling fan 13, and send back signals from various sensors equipping the drive member 1 and/or landing gear management signals equipping the wheel R _M , such as the rotation speed of the wheel R _M , the tire pressure, the temperature of the brake discs, etc.

These electrical harnesses comprise first electrical harnesses, not shown here, extending inside the second element 20 from the male coupler 21 into the cylindrical body 10, and second electrical harnesses 31, 32, 33 extending from the female coupler 30 and traveling along the main compass and the secondary compass to go up along the rod T to the structure S of the aircraft A. The second harnesses 31, 32, 33 are connected, via the female coupler 30, to the first harnesses.

The second element 20 is equipped with an axial locking device 100 of the drive member 1 in a connected position in which the male coupler 21 is received in the female coupler 30.

Referring to Figures 4 and 5A-5B, the locking device 100 comprises a tubular body 101 having a first end provided with radially projecting external fixing ears 101.1, and a second end, opposite the first end, provided with an external annular groove 101.2. The ears 101.1 are symmetrically distributed around the Y axis ₁₀₁ and each comprise a tapped bore 101.3 extending substantially parallel to said Y axis _101. The groove 101.2 comprises a bottom 101.4 of truncated cone shape, the large base of which here delimits a front face 101.5 of the body 101. The bottom 101.4 forms an angle α with the Y axis ₁₀₁ .

The body 101 also comprises three longitudinal slots 101.6 symmetrically distributed around the Y axis _101. The slots 101.6 extend parallel to the Y axis ₁₀₁ from the ears 101.1 to the front face 101.5 and open onto said front face 101.5, forming peripheral notches 101.7 which define passages P for electrical beams. The slots 101.6 delimit three branches 101.8 connecting the ears 101.1 to the front face 101.5.

The body 101 of the locking device 100 is received in a fit manner in the second element 20 of the drive member 1 and is mounted to be movable in translation, along the Y axis, in said second element 20 between an advanced position ( ) and a retracted position ( ) by means of tightening screws 102 passing through the tapped bores 101.3 of the ears 101.1 of the body 101.

The locking device 100 also comprises locking segments 103 symmetrically distributed two by two around the Y axis _101. The segments 103 are mounted to move radially in openings 22 provided in the second element 20, between a locking position in which the segments 103 project from an external surface of the second element 20 ( ), and a release position in which the segments 103 are set back from the external surface of the second element 20 and towards which they are returned by elastic return means (not shown). The segments 103 are for example carried by an elastically deformable open ring between a rest state in which the open ring has a diameter substantially equal to the small diameter of the bottom 101.4 of the groove 101.2 and a deformed state in which the diameter of the open ring is substantially equal to the large diameter of the bottom 101.4 of the groove 101.2.

The bottom 101.4 of the groove 101.2 is arranged to be substantially opposite the openings 22 of the second element 20 and to cooperate with a lower face of the segments 103 so that said segments 103 are brought from the release position to the locking position when the body 101 passes from the advanced position to the retracted position. The bottom 101.4 of the groove 101.2 thus forms a cam surface for moving the segments 103.

The axle E comprises an internal annular groove E ₃ arranged to be substantially opposite the openings 22 of the second element 20 and to receive the segments 103 of the locking device 100 when the drive member 1 is in the connected position and the body 101 of said locking device 100 in the retracted position, said segments 103 cooperating with a side wall E ₄ of the groove E ₃ under the effect of the tensile force exerted by the screws 102 on the body 101. The side wall E ₄ forms with the axis Y an angle β here greater than the angle α.

The assembly sequence of the drive member 1 in the axle E will now be detailed.

We start from the initial situation represented in in which the body 101 of the locking device 100 is in the retracted position, the segments 103 therefore being in the locking position.

After having checked the absence of electric current in the female coupler 30 housed in the axle E, a tool is positioned on the drive member 1 to take up its mass during its insertion into the axle E during which the Y axis ₁₀₁ is substantially merged with the Y axis. The cooling fan 13 is then removed from the motor 11 so as to be able to access the locking device 100 and to bring the body 101 from the retracted position to the advanced position via the loosening of the screws 102, which causes the segments 103 to retract inside the second element 20. The segments 103 then do not oppose the insertion of the second element 20 of the drive member 1 into the axle E.

• un effort F1 exercé par le fond 101.4 de la gorge 101.2, l’effort F1 comprenant une composante axiale F1_aet une composante radiale F1_R;
• un effort F2 exercé par la paroi latérale E₄de la gorge E₃, l’effort F2 comprenant une composante axiale F2_aet une composante radiale F2_r; et
• un effort F3 exercé par une paroi radiale de l’ouverture 22, l’effort F3 comprenant ici une unique composante axiale.

The second element 20 is then inserted into the axle E until the drive member 1 is brought into the connected position in which the male coupler 21 is received in the female coupler 30. By tightening the screws 102, the body 101 of the locking device 100 tends to return to its retracted position. The segments then slide radially through the openings 22 towards the outside of the second element 20 until they reach their locking position in which the segments 103 are received in the groove E ₃ formed in the axle E. By continuing to tighten the screws 102, the segments 103 cooperate with the side wall E ₄ of the groove E ₃ and exert an axial thrust force on the stator 11.1 of the motor 11 causing said stator 11.1 to be pressed against the dog teeth E ₁ . The fan 13 can then be reassembled on the motor 11. illustrates all the forces exerted on each of the segments 103 in the locked position. We distinguish:

• a force F1 exerted by the bottom 101.4 of the groove 101.2, the force F1 comprising an axial component F1 _a and a radial component F1 _R ;
• a force F2 exerted by the side wall E ₄ of the groove E ₃ , the force F2 comprising an axial component F2 _a and a radial component F2 _r ; and
• a force F3 exerted by a radial wall of the opening 22, the force F3 here comprising a single axial component.

It should be noted that, because here the angles α and β are different, the combination of the forces F1 and F2 generates the force F3 responsible for the plating of the stator 11.1 against the dog teeth E ₁ .

Disassembly of the drive unit 1 is carried out in the reverse order of assembly.

• maintenir axialement l’organe d’entraînement 1 en position connectée ;
• transmettre le couple délivré par le moteur 11 à la roue R_Mpar l’engagement des dents de crabotage E₁de l’essieu E dans les logements ménagés dans le stator 11.1 dudit moteur 11 ;
• maintenir plaqué le stator 11.1 du moteur 11 contre les dents de crabotage E₁de l’essieu E ;
• former un conduit sécurisé de passage de câbles (électriques, hydrauliques..), d’éléments mécaniques (bielle, levier, fixation…), d’équipements (ventilateur monté dans l’essieu…)… ; et
• d’assurer un montage/démontage rapide et sécurisé de l’organe d’entraînement 1, ce qui facilite les opérations de maintenance.

Such a locking device 100 makes it possible in particular to:

• axially hold the drive member 1 in the connected position;
• transmit the torque delivered by the motor 11 to the wheel R _M by engaging the dog teeth E ₁ of the axle E in the housings provided in the stator 11.1 of said motor 11;
• keep the stator 11.1 of the motor 11 pressed against the dog teeth E ₁ of the axle E;
• form a secure conduit for the passage of cables (electrical, hydraulic, etc.), mechanical elements (connecting rod, lever, fixing, etc.), equipment (fan mounted in the axle, etc.); and
• to ensure rapid and safe assembly/disassembly of the drive unit 1, which facilitates maintenance operations.

Each of the branches 101.8 of the body 101 is dimensioned to withstand without failure the rupture of one of the other branches 101.8 and to guarantee the detection of said rupture during a scheduled inspection before a new rupture. The locking device 100 is thus designed according to the “fail-safe” principle.

Of course, the invention is not limited to the embodiment described but encompasses any variant falling within the scope of the invention as defined by the claims.

Although the 101 body is a single piece here, it can be made in several pieces.

The number of branches constituting the body 101 of the locking device 100 may be less than or greater than three.

The number of segments 103 may be different from that of the locking device 100 described.

The segments 103 can be replaced by any obstacle that can be engaged in a groove to achieve locking (ball, split ring, claw, ratchet, etc.).

The front face 101.5 of the body 101 may comprise at least one hole forming another passage for electrical beams.

Although the movement of the body 101 between the advanced position and the retracted position is here ensured by the screws 102, it can also be ensured by helical springs, elastically deformable washers, etc.

Although the motor 11 is here electric, it can be hydraulic. The bundles are then formed of rigid pipes of pressurized hydraulic fluid intended for the motor 11, and the end of the second tubular element 20 carries a hydraulic coupler.

Although here the end of the tubular element 20 of the drive member 1 carries a male coupler 21, it can on the contrary carry a female coupler adapted to receive a male coupler inserted into the axle E via the orifice E ₂ after insertion of the drive member 1 into said axle E.

The dog teeth E ₁ bordering the free end of the axle E can be replaced by any mechanical means allowing said axle E to be coupled to the stator of the motor 11 (splines, key, etc.).

Although the bottom 101.4 of the groove 101.2 is here of a truncated cone shape, any other shape defining a cam surface allowing the segments 103 to be moved from the release position to the locking position can be envisaged.

Claims (10)

Assembly comprising a first tubular element (20) intended to be received in a fit manner in a second tubular element (E), and an axial locking device (100) for the first element in the second element, the locking device comprising at least one obstacle (103) mounted to move radially through an opening (22) in the first element between a locking position in which the obstacle extends projecting from an external surface of the first element and a release position in which the obstacle extends back from the external surface. Assembly according to claim 1, in which the obstacle (103) is returned to the release position by elastic return means. An assembly according to any preceding claim, wherein the locking device (100) comprises a tubular body (101) mounted axially movable in the first element (20) between a retracted position and an advanced position, the body comprising a cam surface (101.4) shaped to cooperate with a lower surface of the obstacle (103) and bring the obstacle from the release position to the locking position when the body passes from the advanced position to the retracted position. Assembly according to claim 3, in which the body (101) comprises an external annular groove (101.2) having a bottom (101.4) of truncated cone shape, the bottom forming the cam surface. Assembly according to claim 3 or 4, in which the body (101) comprises at least one cable passage conduit (P) opening onto a front face (101.5) of the body. Assembly according to claim 5, in which the cable passage conduit (P) comprises at least one longitudinal slot (101.6) opening onto the front face (101.5) of the body (101) forming a notch (101.7). Drive member (1) for rotating a wheel (R _M ) arranged to be pivotally mounted on an axle (E) of an aircraft landing gear about an axis (Y), the drive member comprising an assembly according to any one of the preceding claims, the first element (20) being intended to be received for adjustment in the axle (E). Wheel (R _M ) pivotally mounted on a shaft (E) of an aircraft landing gear (P), the wheel being equipped with a drive member (1) according to claim 7. Aircraft landing gear (P) comprising an axle (E) on which is rotatably mounted a wheel (R _M ) according to claim 8, the axle (E) comprising an internal annular groove (E ₃ ) arranged to receive and cooperate with the obstacle (103) of the locking device (100) when the drive member (1) is in the connected position in the axle (E) and said obstacle (103) in the locking position. Aircraft (A) comprising at least one landing gear (P) according to claim 9.