Electromagnetically controlled parking brake device, and aircraft wheel and aircraft provided with such a device

Abstract

The invention relates to a device for preventing the rotation of a wheel (1) rotatably mounted on an axle (2) so as to rotate about an axis of rotation (X), the device comprising a receiving member (4) that is rigidly attached to the wheel and provided with an internal face that has regularly distributed axial cavities (4e); a rotationally stationary cage (6) that extends around the axle facing the receiving member, the cage comprising axial recesses (6a) that accommodate segments (7) that are movable in the cage in respective radial directions between an engagement position in which the segments are engaged in the receptacles in the receiving member and a release position in which the segments are disengaged from the receptacles in the receiving member; a push member (5) made of a material capable of channelling a magnetic flux, the push member extending around the axle in order to co-operate with the segments via oblique bearing surfaces and mounted so as to move axially between a locking position in which the push member forces the segments into the engagement 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 maintaining it therein; a permanent magnet (14) exerting an electromagnetic force on the push member designed to maintain the push member in the unlocking position against the force of the return member; an electromagnet (15) that can be selectively powered so as to counteract the force of the permanent magnet in order to allow the push member to move from the unlocking position to the locking position under the effect of the return member or to enhance the force of the permanent magnet in order to move the push member from the locking position to the unlocking position against the force of the return member. The invention also relates to a wheel and an aircraft provided with such a device.

Description

[0001] ELECTROMAGNETICALLY CONTROLLED PARKING BRAKING DEVICE, AIRCRAFT WHEEL AND AIRCRAFT EQUIPPED WITH SUCH A DEVICE

[0002] The present invention relates to the field of parking braking or immobilization of aircraft on the ground.

[0003] BACKGROUND OF THE INVENTION

[0004] Climate change is a major concern for many legislative and regulatory bodies around the world. Indeed, various carbon emission restrictions have been, are being, or will be adopted by various states. In particular, an ambitious standard applies to both new aircraft types and those currently in operation, requiring the implementation of technological solutions to bring them into compliance with current regulations. Civil aviation has been mobilizing for several years now to contribute to the fight against climate change.

[0005] 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 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.

[0006] 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 to reduce the environmental footprint of its activity.

[0007] This sustained research and development work focuses both on lightening the devices, particularly through the materials used and lightened on-board equipment, and the development of the use of electrical technologies.

[0008] In general, aircraft are immobilized on the ground by permanently supplying power to the aircraft brakes so that they prevent the braked wheels from turning. In the case of aircraft equipped with hydraulic brakes, the brakes are connected to an accumulator providing the pressure necessary to actuate the brakes. The aircraft is thus immobilized as long as the accumulator is kept in hydraulic connection with the brakes. In the case of aircraft equipped with electric brakes, it has been proposed, for example in document FR2880602, to maintain the braking actuators in the braking position by means of a bistable locking member locking the braking actuators in the braking position without it being necessary to supply power to the braking actuators.

[0009] However, these locking modes constantly stress the brakes and brake friction components, which can lead to accelerated fatigue.

[0010] SUBJECT OF THE INVENTION

[0011] The invention aims to propose a means of locking an aircraft wheel without applying the aircraft brakes.

[0012] SUMMARY OF THE INVENTION

[0013] 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 secured to the wheel and comprising an internal face having regularly distributed axial cavities facing the axle; - a cage extending around the axle opposite the receiver and held stationary in rotation, the cage comprising axial housings receiving segments 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 released from the receptacles of the receiver;

[0014] - a pusher member made of a material capable of channeling a magnetic flux and extending around the axle to cooperate with the segments by oblique bearing surfaces, and 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;

[0015] - a return member for returning the push member to its locking position and holding it there;

[0016] - a permanent magnet inducing on the push member an electromagnetic force adapted to maintain the push member in the unlocked position against the return member;

[0017] - a selectively energized electromagnet 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.

[0018] The device of the invention therefore allows the wheel to be locked without using the brake. It can therefore be fitted to unbraked wheels. Of course, if during locking the segments are not facing the receptacles, it will be sufficient to cause a slight rotation of the wheel to bring them there and thus allow the wheel to be locked. The power supply to the electromagnet can be interrupted as soon as the pusher member has reached one or other of its positions, each of the positions being stable. Thus, since the locking device does not need to be constantly powered, the electrical consumption of the locking device of the invention is very low. In addition, the device of the invention is compact, lightweight, independent, and can be implemented easily and directly with few modifications to be made to the wheel.

[0019] According to a particular aspect of the invention, the pusher member comprises an outer part having slots through which the segments extend, the slots having oblique distal flanks forming oblique bearing surfaces cooperating with distal oblique surfaces of the segments to bring them from the locking position to the release position.

[0020] According to another particular aspect of the invention, the pusher member comprises a skirt having a truncated conical surface forming oblique bearing surfaces cooperating with proximal oblique surfaces of the segments to bring the latter from the release position to the locking position.

[0021] According to yet another particular aspect, the device of the invention comprises a torsion tube threaded onto the axle and stopped in rotation relative to the axle, the torsion tube having a tubular part having a grooved external surface cooperating with homologous internal surfaces of the pusher member and the cage. Preferably then, the torsion tube comprises a plate against which the return member bears.

[0022] According to a particular arrangement of the invention, the permanent magnet and the electromagnet are part of an electromagnetic actuator extending around the pusher member.

[0023] 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 push member coming into abutment against the cover in the unlocked position.

[0024] According to yet another particular arrangement, the segments comprise a locking portion penetrating into the receptacles of the receiver, each locking portion comprising 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 undergoes a torque greater than a determined threshold.

[0025] The invention also relates to an aircraft wheel equipped with such a device and an aircraft comprising at least one such wheel.

[0026] Other characteristics and advantages of the invention will emerge from reading the following description of a particular and non-limiting embodiment of the invention.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Reference will be made to the figures in the attached drawings, including:

[0029] [Fig. 1] Figure 1 is a perspective view of the locking device according to a particular embodiment of the invention;

[0030] [Fig. 2] Figure 2 is a sectional view of the locking device of Figure 1 installed around an axle carrying a wheel to be locked, the device being shown here in the unlocked position;

[0031] [Fig. 3] Figure 3 is a sectional view similar to that of Figure 2, the device being shown here in the locked position;

[0032] [Fig. 4] Figure 4 is an enlarged side view at one of the segments shown in the locking position;

[0033] [Fig. 5] Figure 5 is an enlarged front view at one of the segments shown in the locked position.

[0034] DETAILED DESCRIPTION OF THE INVENTION

[0035] 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 to rotate by means of roller bearings 3 along an axis of rotation X. For the following, the face of the parts facing the axle will be called the internal face, while the face of the parts facing the wheel will be called the external face.

[0036] 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 it from rotating (for example fixed to a handle of the axle, or even prevented from rotating by a brake bar attached to the landing gear carrying the axle).

[0037] The device comprises a receiver 4 secured to the wheel 1 and comprising a cylindrical external surface 4a received in a fitting manner in a conforming 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 comprises an internal surface 4c having protrusions 4d defining between them axial receptacles with oblique sides 4e facing the axle 2.

[0038] Opposite the receiver 4 extends a cage 6 having a grooved internal surface cooperating with the grooved external surface of the opposite torque tube 9 for stopping it from rotating. The cage 6 comprises a series of axial housings 6a passing through each intended to receive a segment 7. The segments 7 are received in the axial housings 6a to be 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 latter axially.

[0039] To move the segments 7 between these two positions, the locking device comprises a pusher member 5, made of a material capable of channeling a magnetic flux, here made in two parts including an inner part 5a and an outer part 5b for the purposes of mounting the device, but secured to each other in service as illustrated in Figures 2 and 3. The inner part 5a comprises a grooved inner surface cooperating with the grooved outer surface of the torque tube 9 to stop it from rotating thereon while allowing axial movement of the pusher member 5.

[0040] The outer part 5b has the shape of a cylindrical sleeve which covers the cage 6 in use and which has openings 5d directly above the housings of the cage 6 to allow the segments 7 to project from the pusher member 5 and engage in the receptacles 4e of the receiver 4 when they are 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 part 5a comprises a skirt 5c having a truncated cone-shaped surface forming oblique bearing surfaces adapted to cooperate with proximal oblique surfaces 7b of the segments 7.

[0041] In the situation illustrated in Figure 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 them and hold them in the release position in which the segments 7 are retracted into the housings of the cage 6 and therefore released from the receptacles 4e.

[0042] In the situation illustrated in Figure 3, the pusher member 5 is in an axial locking position in which the skirt 5c cooperates with the oblique surfaces facing the segments 7 to push them and hold them in the locking position in which the segments 7 project radially from the pusher member 5 through the slots 5d and are engaged in the receptacles 4e.

[0043] The locking device finally comprises elements for moving and maintaining the push member 5 in one or other of its positions, comprising:

[0044] - 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;

[0045] - an electromagnetic actuator 13 extending around the pusher member 5 and comprising a cover 13a secured to a lid 13b, both made of a material capable of channeling a magnetic flux, the lid 13b extending against the plate 9b of the torsion tube opposite a proximal face 5f of the pusher member 5 which abuts against the cover 13b in the unlocked position. The electromagnetic actuator 13 contains a permanent magnet 14 and an electromagnet 15 which can be selectively powered to counter the flux of the permanent magnet 14 or, on the contrary, to increase the flux of the permanent magnet 14.

[0046] The operation of the locking device of the invention is as follows. In the position illustrated in Figure 2, the push member is in the unlocking position, pressing against the cover 13b of the electromagnetic actuator 13. In this position, the magnetic flux of the permanent magnet 14 loops through the cover 13a, the cover 13b, then, crossing the small air gap between the cover 13b and the push member 5, through the push member 5 to return to the permanent magnet 14. Thus looped, the magnetic flux exerts on the push member 5 a magnetic force tending to maintain the latter in the unlocking position against the force of the return member 12. The segments 7 are retracted and released from the receptacles 4e, so that the wheel 1 is free to rotate.

[0047] To move the pusher member 5 from the unlocking position of Figure 2 to the locking position of Figure 3, the electromagnet 15 is powered so as to counter the flux of the permanent magnet 14. The magnetic force generated by the permanent magnet 14 decreases until it can no longer counter the return force exerted by the return member 12 which then moves the pusher member 5 to the locking position and maintains it there. It is then possible to stop powering the electromagnet 15. If the segments 7 were not strictly opposite the receptacles 4e, a slight rotation of the wheel (for example under the action of thrust from the aircraft engine) makes it possible to bring the segments 7 opposite the receptacles and to penetrate there under the thrust of the pusher member 5, itself pushed by the return member 12.

[0048] To move the push member 5 from the locking position of Figure 3 to the unlocking position of Figure 2, the electromagnet 15 is energized in the opposite direction to increase the flux of the permanent magnet 14 and thus generate an electromagnetic force capable of moving the push member 5 against the return member 12 so as to reduce the air gap between the latter and the cover 13b, until the push member 5 comes into abutment against the latter. The flux of the permanent magnet 14 is then sufficient to maintain the push member 5 in the unlocking position against the return member 12. It is then possible to stop energizing the electromagnet 15.

[0049] According to a particular aspect of the invention more particularly visible in figures 4 and 5 in which the clearances have been exaggerated, the segments 7 comprise a guide portion 7c having parallel lateral flanks 7d cooperating in adjustment with parallel lateral flanks 6d of the housings 6a of the cage 6 to ensure the radial guidance of the segments 7 during their movement between the release position and the locking position. According to another particular aspect of the invention, the segments 7 comprise a locking portion 7e having oblique lateral flanks 7f intended to cooperate with homologous 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 retraction of the segments 7 into the housings 6a of the cage 6 if the torque exerted on the wheel 1 exceeds a determined threshold fixed by the slopes of the oblique flanks and surfaces. This arrangement allows automatic unlocking of the blocking device of the invention under the effect of the thrust of the engine(s) of the aircraft, or under the effect of a torque imposed on the wheel 1 by an engine.

[0050] 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.

[0051] In particular, although here the return member is constituted by 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.

[0052] Although here the locking device comprises a torsion tube stopped in rotation with a grooved tubular part to stop the rotation of the pusher member 5 and the cage 6 while allowing the axial displacement of the pusher member 5, other means can be used to stop the rotation of the cage and the pusher member, such as the use of keys, or even grooves directly made on the axle.

[0053] It is possible to use any type of bistable linear actuator and for example hydraulic, electrohydraulic, electromechanical actuators...

[0054] The invention is applicable to any system in which the rotation of a part (which will be generally called a wheel) rotating around an axis (which will be generally called an axle) 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) which can be selectively powered to counter the force of the permanent magnet to leave 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.

2. Locking device according to claim 1, in which the pusher member (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. Locking device according to claim 1, further comprising a torsion tube (9) threaded onto the axle (2) and stopped in rotation relative to the axle, the torsion tube having a tubular part (9a) having a grooved external surface cooperating with homologous internal surfaces of the pusher member (5) and of 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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