Electromagnetically controlled parking braking device, aircraft wheel and aircraft equipped with such a device.

Abstract

The invention relates to a device for locking against rotation a wheel (1) mounted rotating on an axle (2) around an axis of rotation (X), comprising a receiver (4) fixed to the wheel and comprising an inner face having regularly distributed axial cavities (4e); a cage (6) extending around the axle opposite the receiver and held immobile against rotation, the cage comprising axial housings (6a) receiving segments (7) movable in the cage in respective radial directions between a locking position in which the segments are engaged in the receptacles of the receiver, and a release position in which the segments are disengaged from the receptacles of the receiver;a push member (5) made of a material suitable for channeling a magnetic flux and extending around the axle to cooperate with the segments by means of oblique bearings, and mounted axially movable between a locking position in which the push member forces the segments into the locking position and an unlocking position in which the push member forces the segments into the release position; a return member (12) for returning the push member to its locking position and holding it there; a permanent magnet (14) inducing on the push member an electromagnetic force suitable for holding the push member in the unlocking position against the return member;an electromagnet (15) that can be selectively powered to counteract the force of the permanent magnet to allow the push member to move from the unlocked position to the locked position under the effect of the return member, or to increase the force of the permanent magnet to move the push member from the locked position to the unlocked position against the return member. Wheel and aircraft equipped with such a device. FIGURE IN ABRIDGED DIAGRAM: Fig. 1;

Description

Title of the invention: Electromagnetically controlled parking braking device, aircraft wheel and aircraft equipped with such a device.

[0001] The present invention relates to the field of parking braking or immobilization of aircraft on the ground.

[0002] BACKGROUND OF THE INVENTION

[0003] Climate change is a major concern for many legislative and regulatory bodies worldwide. Indeed, various restrictions on carbon emissions have been, are being, or will be adopted by various states. In particular, an ambitious standard applies to both new types of aircraft and those currently in operation, requiring the implementation of technological solutions to bring them into compliance with current regulations. Civil aviation has been actively working for several years now to contribute to the fight against climate change.

[0004] Technological research efforts have already led to very significant improvements in the environmental performance of aircraft. All stakeholders in the sector are constantly working to improve energy efficiency. The Applicant takes into account the factors impacting all phases of design and development in order to obtain aeronautical components and products that are less energy-intensive, more environmentally friendly, and whose integration and use in civil aviation have moderate environmental impacts, with the aim of improving the energy efficiency of air transport.

[0005] Consequently, the Applicant is constantly working to reduce its climate impact by using methods and operating virtuous development and manufacturing processes that minimize greenhouse gas emissions in order to reduce the environmental footprint of its activity.

[0006] This sustained research and development work focuses both on the lightening of devices, in particular through the materials used and lighter on-board equipment, and on the development of the use of electrical technologies.

[0007] Generally, aircraft are immobilized on the ground by continuously supplying the aircraft brakes so that they prevent the braked wheels from rotating. In the case of aircraft equipped with hydraulic brakes, the brakes are connected to an accumulator that provides the pressure necessary to actuate the brakes. The aircraft is thus immobilized as long as the accumulator remains hydraulically connected to the brakes. In the case of aircraft equipped with electric brakes, it has been proposed, for example in document FR2880602, to maintain the brake actuators in the braking position by means of a bistable locking device which locks the brake actuators in the braking position without it being necessary to supply the brake actuators.

[0008] However, these locking methods constantly stress the brakes and the friction elements of the brakes, which can lead to accelerated fatigue.

[0009] SUBJECT OF THE INVENTION

[0010] The invention aims to provide a means of locking an aircraft wheel without using the aircraft brakes. Summary of the invention

[0011] To this end, the invention provides a device for locking the rotation of a wheel mounted to rotate on an axle around an axis of rotation, the device comprising: - a receiver attached to the wheel and having an internal face with regularly distributed axial cavities facing the axle; - a cage extending around the axle opposite the receiver and held immobile in rotation, the cage having axial housings receiving segments movable in the cage in respective radial directions between a locking position in which the segments are engaged in the receiver receptacles, and a release position in which the segments are released from the receiver receptacles; - a pusher made of a material suitable for channeling a magnetic flux and extending around the axle to cooperate with the segments by means of oblique bearings, and mounted axially movable between a locking position in which the pusher forces the segments into the locking position and an unlocking position in which the pusher forces the segments into the release position; - a return mechanism to return the pusher to its locking position and hold it there; - a permanent magnet inducing on the pusher member an electromagnetic force adapted to maintain the pusher member in the unlocked position against the return member; - a selectively powered electromagnet to counteract the force of the permanent magnet to allow the pusher to move from the unlocked position to the locked position under the effect of the return mechanism, or to increase the force of the permanent magnet to move the pusher from the locked position to the unlocked position against the recall body.

[0012] The device of the invention thus allows the wheel to be locked without using the brake. It can therefore be fitted to unbraked wheels. Of course, if the segments are not aligned with the receptacles during locking, a slight rotation of the wheel will suffice to bring them into alignment and thus lock the wheel. The electromagnet can be switched off as soon as the pusher reaches one of its positions, each position being stable. Thus, since the locking device does not require a constant power supply, the electrical consumption of the locking device of the invention is very low. Furthermore, the device of the invention is compact, lightweight, independent, and can be easily and directly implemented with minimal modifications to the wheel.

[0013] According to a particular aspect of the invention, the pusher member comprises an outer part having openings through which the segments extend, the openings having oblique distal flanks forming oblique bearing surfaces cooperating with distal oblique surfaces of the segments to bring them from the blocking position to the release position.

[0014] According to another particular aspect of the invention, the pusher member comprises a skirt having a frustoconical surface forming oblique bearing surfaces cooperating with proximal oblique surfaces of the segments to bring them from the release position to the blocking position.

[0015] According to yet another particular aspect, the device of the invention comprises a torsion tube threaded onto the axle and prevented from rotating relative to the axle, the torsion tube having a tubular portion with a grooved external surface cooperating with corresponding internal surfaces of the pusher member and the cage. Preferably, the torsion tube comprises a plate against which the return member bears.

[0016] According to a particular arrangement of the invention, the permanent magnet and the electromagnet form part of an electromagnetic actuator extending around the pusher member.

[0017] Preferably then, the electromagnetic actuator comprises a hood and a cover capable of channeling a magnetic flux, the cover extending opposite a proximal face of the pusher member which comes to rest against the cover in the unlocked position.

[0018] According to yet another particular arrangement, the segments have a locking portion penetrating the receptacles of the receiver, each locking portion having oblique flanks cooperating with homologous flanks of the receptacles, so that the segments are pushed from the locking position to the release position if the wheel experiences a torque greater than a determined threshold.

[0019] The invention also relates to an aircraft wheel equipped with such a device and an aircraft comprising at least one such wheel.

[0020] Other features and advantages of the invention will become apparent from the following description of a particular, non-limiting embodiment of the invention. Brief description of the drawings

[0021] Reference will be made to the figures in the attached drawings, among which:

[0022] [Fig-1] [Fig.1] is a perspective view of the locking device according to a mode particular implementation of the invention;

[0023] [Fig.2] [Fig.2] is a cross-sectional view of the locking device of [Fig.1] installed around an axle carrying a wheel to be locked, the device being shown here in the unlocked position;

[0024] [Fig.3] [Fig.3] is a cross-sectional view similar to that of [Fig.2], the device being shown here in the locked position;

[0025] [Fig.4] [Fig.4] is an enlarged side view at the level of one of the segments shown in the locked position;

[0026] [Fig.5] [Fig.5] is an enlarged front view at the level of one of the segments shown in the locking position. DETAILED DESCRIPTION OF THE INVENTION

[0027] With reference to figures 1 to 3, the locking device of the invention is intended to be interposed between a wheel 1 and an axle 2 on which it is mounted for rotation by means of roller bearings 3 about an axis of rotation X. For the following, the face of the parts facing the axle shall be called the inner face, while the face of the parts facing the wheel shall be called the outer face.

[0028] The device here comprises a torsion tube 9 threaded onto the axle 2 and comprising a tubular part 9a having a grooved external surface, and a plate 9b serving to stop its rotation (for example fixed to one hand of the axle, or prevented from rotating by a brake bar attached to the lander carrying the axle).

[0029] The device includes a receiver 4 fixed to the wheel 1 and having an external cylindrical surface 4a received by fitting in a corresponding bore of the wheel 1, and having a series of obstacles 4b received in homologous cavities of the wheel 1 to immobilize the receiver 4 in rotation with the wheel 1. The receiver 4 has an internal surface 4c having protrusions 4d defining between them axial receptacles with oblique flanks 4e turned towards the axle 2.

[0030] Opposite the receiver 4 extends a cage 6 having a grooved inner surface cooperating with the grooved outer surface of the opposing torsion tube 9 to prevent rotation. The cage 6 has a series of through axial recesses 6a, each intended to receive a segment 7. The segments 7 are received in the recesses Axial segments 6a are movable in respective radial directions between a release position in which the segments 7 are disengaged from the receptacles 4e of the receiver 4 as illustrated in [Fig. 2] and a locking position in which the segments 7 are engaged in the receptacles 4e of the receiver 4 as illustrated in [Fig. 3]. A shim 8 is interposed between one of the bearings 3 and the cage 6 to stop the cage axially.

[0031] To move the segments 7 between these two positions, the locking device includes a pusher member 5, made of a material suitable for channeling a magnetic flux, here made in two parts, an inner part 5a and an outer part 5b for the purposes of mounting the device, but joined together in service as illustrated in figures 2 and 3. The inner part 5a has a grooved inner surface cooperating with the grooved outer surface of the torsion tube 9 to stop its rotation on the latter while allowing axial movement of the pusher member 5.

[0032] The outer portion 5b has a cylindrical sleeve shape that, in operation, covers the cage 6 and has openings 5d aligned with the housings of the cage 6 to allow the segments 7 to protrude from the pusher member 5 and engage in the receptacles 4e of the receiver 4 when brought into the locking position. The distal flanks 5e of the openings 5d form oblique bearing surfaces adapted to cooperate with distal oblique surfaces 7a of the segments 7. The inner portion 5a, for its part, comprises a skirt 5c having a frustoconical surface forming oblique bearing surfaces adapted to cooperate with proximal oblique surfaces 7b of the segments 7.

[0033] In the situation illustrated in [Fig.2], the pusher member 5 is in an axial unlocking position in which the oblique distal flanks 5e of the slots 5d cooperate with the oblique surfaces opposite the segments 7 to push and hold them in a release position in which the segments 7 are retracted into the housings of the cage 6 and thus freed from the receptacles 4e.

[0034] In the situation illustrated in [Fig.3], the pusher member 5 is in an axial locking position in which the skirt 5c cooperates with the oblique surfaces opposite the segments 7 to push and hold them in a locking position in which the segments 7 protrude radially from the pusher member 5 through the slots 5d and are engaged in the receptacles 4e.

[0035] The locking device finally includes elements for moving and holding the pusher member 5 in one or the other of its positions, comprising: - a return member comprising here a plurality of helical springs 12 mounted between the plate 9b of the torsion tube 9 and the inner part 5a of the pusher member 5 to return the latter to the locking position; - an electromagnetic actuator 13 extending around the pusher member 5 and comprising a cover 13a integral with a cover 13b, both in The cover 13b, made of a material suitable for channeling a magnetic flux, extends against the plate 9b of the torsion tube opposite a proximal face 5f of the pusher 5, which abuts against the cover 13b in the unlocked position. The electromagnetic actuator 13 contains a permanent magnet 14 and an electromagnet 15 that can be selectively powered to counteract the flux of the permanent magnet 14 or, conversely, to increase the flux of the permanent magnet 14.

[0036] The operation of the locking device of the invention is as follows. In the position illustrated in [Fig. 2], the pusher is in the unlocked position, resting against the cover 13b of the electromagnetic actuator 13. In this position, the magnetic flux of the permanent magnet 14 loops back through the cover 13a, the cover 13b, then, passing through the small air gap between the cover 13b and the pusher 5, through the pusher 5 to return to the permanent magnet 14. Thus looped, the magnetic flux exerts a magnetic force on the pusher 5 tending to maintain it in the unlocked position against the force of the return member 12. The segments 7 are retracted and disengaged from the receptacles 4e, so that the wheel 1 is free to rotate.

[0037] To move the pusher 5 from the unlocked position in [Fig. 2] to the locked position in [Fig. 3], the electromagnet 15 is energized to counteract the magnetic flux of the permanent magnet 14. The magnetic force generated by the permanent magnet 14 decreases until it can no longer counteract the restoring force exerted by the restoring member 12, which then moves the pusher 5 to the locked position and holds it there. The electromagnet 15 can then be de-energized. If the segments 7 were not precisely opposite the receptacles 4e, a slight rotation of the wheel (for example, under the action of a thrust from the aircraft engine) allows the segments 7 to be brought into alignment with the receptacles and inserted under the thrust of the pusher 5, itself pushed by the restoring member 12.

[0038] To move the pusher 5 from the locked position in [Fig. 3] to the unlocked position in [Fig. 2], the electromagnet 15 is energized in the opposite direction to increase the flux through the permanent magnet 14 and thus generate an electromagnetic force capable of moving the pusher 5 against the return member 12, thereby reducing the air gap between the latter and the cover 13b, until the pusher 5 comes to rest against the latter. The flux through the permanent magnet 14 is then sufficient to hold the pusher 5 in the unlocked position against the return member 12. The electromagnet 15 can then be de-energized.

[0039] According to a particular aspect of the invention, more particularly visible in Figures 4 and 5, in which the gaps have been exaggerated, the segments 7 comprise a portion of guide 7c having parallel lateral flanks 7d cooperating in adjustment with parallel lateral flanks 6d of the housings 6a of the cage 6 to ensure radial guidance of the segments 7 during their movement between the release position and the locking position.

[0040] According to another particular aspect of the invention, the segments 7 comprise a locking portion 7e having oblique lateral flanks 7f designed to cooperate with corresponding oblique flanks 4f of the receptacles 4e. The slope of the oblique lateral flanks 7f of the segments 7 (and therefore that of the oblique flanks 4f of the receptacles 4e) as well as the slope of the proximal oblique surface 7b of the segments 7 (and therefore that of the skirt 5c of the pusher member 5) are chosen to cause the segments 7 to retract into the housings 6a of the cage 6 if the torque exerted on the wheel 1 exceeds a predetermined threshold set by the slopes of the flanks and oblique surfaces. This arrangement allows for automatic unlocking of the locking device of the invention under the effect of the thrust of the aircraft engine(s), or under the effect of a torque imposed on the wheel 1 by an engine.

[0041] 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.

[0042] In particular, although here the return member consists of a plurality of springs 12, these can be replaced by a return member in the form of a single spring or a set of spring washers arranged in series between the plate 9b of the torsion tube 9 and the inner part 5a of the pusher member 5.

[0043] Although here the locking device comprises a torsion tube stopped in rotation with a grooved tubular part to stop the pusher member 5 and the cage 6 in rotation while allowing axial movement of the pusher member 5, other means may be used to stop the cage and the pusher member in rotation, such as the use of keys, or even grooves made directly on the axle.

[0044] It is possible to use any type of bistable linear actuator and for example hydraulic, electrohydraulic, electromechanical actuators...

[0045] The invention is applicable to any system in which the rotation of a part (which will be called a wheel in general) rotating around an axis (which will be called an axle in general) must be blocked.

Claims

Claims

1. Device for locking the rotation of a wheel (1) mounted to rotate on an axle (2) around an axis of rotation (X), the device comprising: - a receiver (4) secured to the wheel and comprising an internal face having regularly distributed axial cavities (4e) facing the axle; - a cage (6) extending around the axle opposite the receiver and held stationary in rotation, the cage comprising axial housings (6a) receiving segments (7) movable in the cage in respective radial directions between a locking position in which the segments are engaged in the receptacles of the receiver, and a release position in which the segments are disengaged from the receptacles of the receiver; - a pusher member (5) made of a material capable of channeling a magnetic flux, which extends around the axle to cooperate with the segments by oblique bearing surfaces and which is mounted axially movable between a locking position in which the pusher member forces the segments into the locking position and an unlocking position in which the pusher member forces the segments into the release position; - a return member (12) for returning the push member to its locking position and holding it there; - a permanent magnet (14) inducing on the push member an electromagnetic force adapted to maintain the push member in the unlocked position against the return member; - an electromagnet (15) selectively energized to counter the force of the permanent magnet to allow the push member to move from the unlocking position to the locking position under the effect of the return member, or to increase the force of the permanent magnet to move the push member from the locking position to the unlocking position against the return member.

2. A locking device according to claim 1, wherein the member pusher (5) comprises an outer part (5b) having slots (5d) through which the segments (7) extend, the slots having oblique distal flanks (5e) forming oblique bearing surfaces cooperating with distal oblique surfaces (7a) of the segments to bring them from the locking position to the release position.

3. Locking device according to claim 1, in which the pusher member (5) comprises a skirt (5c) having a frustoconical surface forming oblique bearing surfaces cooperating with proximal oblique surfaces (7b) of the segments (7) to bring the latter from the release position to the locking position.

4. A locking device according to claim 1, further comprising a torque tube (9) threaded onto the axle (2) and stopped in rotation relative to the axle, the torque tube having a tubular portion (9a) having a grooved external surface cooperating with homologous internal surfaces of the pusher member (5) and the cage (6).

5. Device according to claim 4, in which the torsion tube comprises a plate (9b) against which the return member (12) bears.

6. Device according to claim 1, in which the permanent magnet (14) and the electromagnet (15) are part of an electromagnetic actuator (13) extending around the pusher member (5).

7. Locking device according to claim 6, in which the electromagnetic actuator (13) comprises a cover (13a) and a lid (13b) capable of channeling a magnetic flux, the lid extending opposite a proximal face (5f) of the push member (5) coming into abutment against the lid in the unlocked position.

8. Locking device according to claim 1, in which the segments (7) comprise a locking portion (7e) penetrating into the receptacles (4e) of the receiver (4), each locking portion comprising oblique flanks (7f) cooperating with homologous flanks (4f) of the receptacles (4e), so that the segments are pushed from the locking position to the release position if the wheel (1) undergoes a torque greater than a determined threshold.

9. Aircraft wheel (1) equipped with a device according to any one of the preceding claims.

10. Aircraft comprising at least one wheel (1) according to claim 9.

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