Vehicle braked wheel actuated by deformable parallelograms, aircraft landing gear and aircraft equipped with such a wheel

Abstract

A magnetic braking device (1) with eddy currents comprises two external elements (2) framing a central element (3) aligned on the same axis with the external elements and rotating about said axis relative to the external elements (2). Each external element (2) carries a plurality of magnets (11, 12, 13, 14) capable of emitting a magnetic flux that generates eddy currents in the central element (3) when the elements (2, 3) are in relative motion. The magnets are arranged to generate a magnetic attraction between the external elements. Friction braking surfaces are rotationally linked to the external elements and the central element, respectively.The external elements are movable relative to the axis between a position close to the central element, in which the first braking surfaces are held against the second braking surfaces by magnetic attraction, and a position away from the central element, in which the first braking surfaces are separated from the second braking surfaces. Aircraft wheel and landing gear incorporating such a device. ABRIDGED FIGURE: Fig. 3.

Description

Title of the invention: Vehicle braked wheel actuated by deformable parallelograms, aircraft landing gear and aircraft equipped with such a wheel

[0001] The present invention relates to the field of braking of vehicle wheels such as aircraft wheels.

[0002] BACKGROUND OF THE INVENTION

[0003] An aircraft wheel generally comprises a rim connected by a disc to a hub mounted to rotate on a wheel support shaft (axle or spindle).

[0004] Friction braking devices are known to comprise a stack of brake discs housed in an annular space extending between the rim and the hub, and comprising alternating rotor discs connected in rotation with the wheel and stator discs fixed relative to the wheel support shaft. The braking device also includes hydraulic or electromechanical actuators mounted on an actuator carrier and arranged to apply a controlled braking force to the stack of discs so as to brake the rotation of the wheel.

[0005] Eddy current magnetic braking devices (also called "Eddy current" devices) used for braking vehicle wheels, and more particularly aircraft wheels, are also known. Document FR-A-3122405 describes such a device comprising a rotor rotationally fixed to the wheel, two stators flanking the rotor that are rotationally fixed to the wheel support shaft and free to translate relative to said shaft, magnets for producing an axial magnetic flux between the stators and the rotor, and at least one actuator for axially moving the stators between a maximum braking position in which the stators are close to the rotor and a free rotation position in which the stators are far from the rotor.It should be noted that, in the free rotation position, the braking device can still generate a braking torque, called residual torque, which is negligible compared to the maximum braking torque and insufficient to significantly slow down the aircraft.

[0006] In general, the actuators ensuring the relative axial displacement of the stators and the rotor are relatively bulky and heavy, and their positioning is relatively restrictive for the design of the wheel.

[0007] SUBJECT OF THE INVENTION

[0008] The invention aims in particular to provide a braked wheel which at least partially remedies the aforementioned disadvantages. Summary of the invention

[0009] For this purpose, according to the invention, a vehicle wheel comprising a hub is provided to pivot around a support shaft defining an axis of rotation of the wheel, a rim extending around the hub, a disc connecting the rim to the hub, and a braking device which includes at least two external elements fixed in rotation with respect to one of the shaft and the rim, a central element disposed between the external elements and fixed in rotation with respect to the other of the shaft and the rim, and at least one actuator for axially moving the external elements between a maximum braking position in which the external elements are close to the central element and a free rotation position in which the external elements are away from the central element. The external elements are connected to each other by at least one deformable parallelogram mechanism comprising at least two extreme joints each linked to one of the external elements and a central joint fixed axially in translation, the actuator being arranged to move one of the extreme joints relative to the central joint to cause a pivoting of the deformable parallelograms resulting in an axial displacement of the external elements relative to the central element.

[0010] Thus, the deformable parallelogram mechanism allows the two external elements to be moved symmetrically, simultaneously, and in opposite directions along a common axis. This mechanism is simple, reliable, and relatively compact. This compact mechanism thereby reduces the mass and complexity of the braking device actuation system.

[0011] According to optional features, used individually or in whole or in part in combination: - the mechanism comprises at least two external parallelograms, each of which includes one of the extreme joints and which are linked together by means of two central bars having centers connected by the central joint; - the central bars are shared by the external parallelograms; - the mechanism includes two intermediate parallelograms, each sharing bars with one of the external parallelograms, the central bars being shared by the intermediate parallelograms; - the external elements, the actuator and the deformable parallelogram mechanism are fixed in rotation relative to the shaft and the central element is fixed in rotation relative to the rim; - the braking device includes a torsion tube which is rotationally linked to the shaft and on which the external elements are mounted to slide axially, the central joint being fixed to the torsion tube; - The braking device is of the eddy current magnetic type, comprising magnets producing a between the external and central elements axial magnetic flux; - the braking device is of the friction type, the external and central elements having friction surfaces.

[0012] The invention also relates to a lander equipped with such a wheel and an aircraft equipped with such a lander.

[0013] Other features and advantages of the invention will become apparent from the following description of particular, non-limiting embodiments of the invention. Brief description of the drawings

[0014] Reference will be made to the attached drawings, among which:

[0015] [Fig-1] [Fig.1] is a partial schematic view of an aircraft equipped of landing gear according to the invention;

[0016] [Fig.2] [Fig.2] is a half-axial cross-sectional view of a wheel according to the invention, wheel being devoid of its tire, the external elements of the braking device being in a position of free rotation;

[0017] [Fig.3] [Fig.3] is an enlarged view of the central area of ​​[Fig.2];

[0018] [Fig.4] [Fig.4] is a schematic top view of the parallel mechanism deformable graphs when the external elements of the braking device are in a position of free rotation;

[0019] [Fig.5] [Fig.5] is a schematic top view of the parallel mechanism deformable graphs when the external elements of the braking device are in the maximum braking position;

[0020] [Fig.6] [Fig.6] is a schematic top view of the parallel mechanism deformable lograms according to an alternative embodiment, when the external elements of the braking device are in a position of free rotation;

[0021] [Fig.7] [Fig.7] is a schematic top view of the parallel mechanism deformable lograms according to this variant of the embodiment, when the external elements of the braking device are in the maximum braking position;

[0022] [Fig.8] [Fig.8] is a front view of the main surface of one of the external elements;

[0023] [Fig.9] [Fig.9] is a partial schematic axial cross-sectional view of an element external according to an alternative embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0024] With reference to the figures, the invention is described in application to an aircraft 100 comprising landing gear 101. Each landing gear 101 comprises a leg having a first end articulated to a structure of the aircraft and, at the opposite end, a second, free end provided with two coaxial shafts 102 on each of which a wheel 103 is mounted to pivot. Each shaft 102 defines the axis of rotation of the wheel 103 which it carries. The landers 101 are here of the retractable type but the invention is applicable to fixed landers, or even to another type of vehicle such as a land vehicle.

[0025] Each wheel 103 here comprises, in a manner known per se, two half-wheels which are each made in one piece and which are bolted to each other, but each half-wheel could be made up of several pieces or, conversely, the wheel could also be made in the form of a single piece.

[0026] Only the half-wheel 103.1 is visible in the figures. The half-wheel 103.1 comprises a hub portion 104.1 and a rim portion 105.1 connected to the hub portion 104.1 by a disc portion 106.1. The rim portion 105.1 has an annular shape having a first annular edge integral with the disc portion 106.1 and a second, opposite annular edge provided with a lip 107.1. The rim portion 105.1 extends opposite the hub portion 104.1: together they define an annular space 108 having one end at least partially closed by the disc portion 106.1 and, opposite, an end open on the side of the lip 107.1.

[0027] The non-visible half-wheel has a similar structure except that it does not have an annular space as long as that of the half-wheel 103.1. In this context, we speak of a half-wheel, but also commonly of a half-rim, half-spoke, or half-hub, even though these parts do not represent half of a wheel, rim, spoke, or hub. Each half-wheel here is made of aluminum.

[0028] When the half-wheels are bolted together: - the hub parts form a hub which can be mounted to pivot on the shaft 102; - the rim parts form a rim suitable for receiving a tire between the lips; - the parts of the sail are pressed against each other by the bolts and form a sail transmitting the forces between the hub and the rim.

[0029] The wheels 103 are each equipped with a magnetic braking device 1 partly housed in the annular space 108.

[0030] The magnetic braking device 1 comprises elements fixed in rotation with respect to the shaft 102, or stators 2, and one element fixed in rotation with respect to the half-wheel 103.1, or rotor 3. The stators 2 are distinguished from one another by the letter a or b. Stator 2a is the one located at the entrance of the annular space 108 (on the side of the lip 107.1), and stator 2b is the one located at the bottom of the annular space 108 (on the side of the rim portion 105.1). In this description, the characters a and b are used only when it is necessary to distinguish the stators 2 from one another.

[0031] More specifically here, the stators 2 and the rotor 1 are disc-shaped, coaxial to the wheel 103, therefore having central axes coinciding with the axis of rotation of the wheel. The disk forming the rotor 3 has two opposing principal faces which form the principal surfaces 3.1, 3.2 of the rotor 3: the principal surface 3.1 of the rotor 3 oriented towards the outside of the wheel 103 and the principal surface 3.2 oriented in the opposite direction towards the part of the sail 106.1 of the wheel 103. The disk forming the stator 2a has a principal face forming a principal surface 2.1a of the stator 2a located opposite the principal surface 3.1 of the rotor 3 and the disk forming the stator 2b has a principal face forming a principal surface 2.1b located opposite the principal surface 3.2 of the rotor 3.

[0032] The stators 2 are rotationally linked to the shaft 102 or to the lander leg 101, here by means of a torsion tube 4 (or torque tube) fixed (here by bolting) to an external collar 102' extending outward from the shaft 102 outside the annular space 108, while the rotor 3 is rotationally linked to the wheel 103, here to the rim portion 105.1 of the wheel 103, in a manner known per se, by means of axial bars 109.1 extending radially outward into the wheel 103 from the rim portion 105.1. Thus, the rotor 3 rotates on itself around its central axis relative to the stators 2a, 2b which frame it: during this movement of the rotor 3 in a circumferential direction, the main surfaces 3.1, 3.2 remain opposite the main surfaces 2.1a and 2.1b, parallel to them and separated by a variable air gap e as will be seen later.

[0033] The stators 2 are linked to the torsion tube 4 to slide without rotation on the torsion tube 4 in such a way that each stator 2 is mobile along an axial direction of the torsion tube 4 between a first position, or maximum braking position, in which the rotor 3 and the stator 2 are brought close together and have their main faces 3.1, 2.1a and 3.2, 2.1b separated by a first air gap distance and a second position, or free rotation position, in which the rotor 3 and the stator 2 are moved apart and have their main faces 3.1, 2.1a and 3.2, 2.1b separated by a second air gap distance greater than the first air gap distance.

[0034] The braking device 1 comprises a plurality of actuators, schematically represented as 5, fixed in a ring around the flange 102', each of which has an element, or pusher, movable along a direction of displacement parallel to the axis of rotation of the wheel and whose displacement along this direction is controllable by the aircraft pilot in a manner known per se, to move the stators 2 between the two positions mentioned above. The actuators 5 are herein described as electromechanical or hydraulic linear actuators known per se and will not be further detailed here.

[0035] The pusher of each actuator 5 is connected directly to the stator 2a and is connected to the stator 2b by a mechanism 6 with deformable parallelograms.

[0036] The mechanism 6 comprises two extreme joints 7a, 7b on either side of a central joint 7c. The joints 7a, 7b, 7c are aligned according to the Direction of movement. The central joint 7c has a pivot fixed to the torsion tube 4, preferably on the middle plane of the rotor 3. The extreme joint 7a has a pivot fixed by a clevis 7a' to the stator 2a, and the extreme joint 7b has a pivot fixed by a clevis 7b' to the stator 2b. Since the actuator pusher 5 is connected to the stator 2a, it can be said that the pivot of the extreme joint 7a is also connected to the actuator pusher 5.

[0037] The mechanism 6 comprises at least two external parallelograms PEa, PEb which respectively include one of the extreme joints 7a, 7b and which are linked together via two central bars 8c having centers connected by the central joint 7c.

[0038] In Figures 1 to 5, the first parallelogram PEa comprises two end bars 9a, each having a first end connected to the end joint 7a and a second end connected by an intermediate joint 10a to a first end of one of the central bars 8c. The second parallelogram PEb comprises two end bars 9b, each having a first end connected to the end joint 7b and a second end connected by an intermediate joint 10b to a second end of one of the central bars 8c.

[0039] The extreme, intermediate and central joints include bearings with a low coefficient of friction, such as polytetrafluoroethylene or bronze bearings, needle bearings or others.

[0040] It is understood that, when the actuator pusher 5 is extended (i.e., moved towards the inside of the wheel), it pushes the outermost joint 7a towards the central joint 7c, which is fixed: in doing so, the pusher causes the two outer parallelograms PEa, PEb to be crushed against the central joint 7c ([Fig. 5]). The stators 2 are then simultaneously brought into the maximum braking position.

[0041] Conversely, when the actuator pusher 5 is retracted (i.e., moved outwards from the wheel), it pulls the outermost joint 7a towards the actuator body: in doing so, the pusher causes the two outer parallelograms PEa, PEb to stretch (Figures 2 to 4). The stators 2 are then in a position of free rotation.

[0042] With reference to [Fig.8], each stator 2 has a plurality of magnets capable of generating eddy currents in the rotor 1 when the stator 2 leaves its free rotation position and approaches its maximum braking position and the rotor 3 pivots opposite the stator 2. The magnets, here based on rare earths, are for example 16 in number and are preferably fixed on a magnetic steel support 200, or even on a non-magnetic support.

[0043] The plurality of magnets includes first magnets 11, 13 having a first magnetization vector substantially perpendicular to the main face 2.1 and being separated in pairs by a second magnet 12, 14 having a second magnetization vector substantially perpendicular to the first magnetization vectors of the first two magnets 11, 13, between which the second magnet 12, 14 is located. Recall that the magnetization vector indicates the direction of the magnetic field generated by a magnet and extends in the magnet from the South pole to the North pole. More precisely, the magnets 11, 12, 13, 14 have angular sector shapes. The magnets 11, 12, 13, 14 are arranged in a Halbach pattern, alternating along the circumferential direction of the stator 2 as follows: a magnet 11, a magnet 12, a magnet 13, a magnet 14, a magnet 11, a magnet 12, a magnet 13, a magnet 14, and so on... In this case: - each magnet has its magnetization vector which exits the main face 2.1 (its North pole opens onto the main face 2.1), - each magnet 12 has its own magnetization vector which extends from the neighboring magnet 11 to the neighboring magnet 13, - each magnet 13 has its magnetization vector which enters the main face 2.1 (its South pole opens onto the main face 2.1), - each magnet 14 has its magnetization vector which extends from the neighboring magnet 11 to the neighboring magnet 13.

[0044] It is understood that the magnets 12, 14 arranged on each side of the same magnet 11 have their magnetization vectors oriented in opposite directions.

[0045] The arrangement of the magnets 11, 12, 13, 14 makes it possible to optimize and concentrate the magnetic flux produced by the magnets 11, 13 by reducing the return path of the magnetic flux which passes through the magnets 12, 14 and not through their support whose mass can be reduced since it does not need to ensure a conduction function of the magnetic flux.

[0046] It is understood that: - to induce magnetic braking, the actuators 5 are controlled to bring the stators 2 to the braking position or any intermediate position between the braking position and the free rotation position, an intermediate position in which the stators 2 are sufficiently close to the rotor 3, so that the magnets generate sufficient eddy currents in the rotor 3 to induce the desired braking of the rotor 3, and - to interrupt the magnetic braking, the actuators 5 are controlled to bring the stators 2 into the free rotation position, a position in which the stators 2 are sufficiently far from the rotor 3 so that the magnets do not generate in the rotor 3 eddy currents sufficient to cause significant braking of the rotor 3.

[0047] It should be noted that below a certain rotational speed of the rotors 1, the torque of Braking is negligible regardless of the stator position. An additional brake may therefore need to be considered.

[0048] At these low speeds, or when the aircraft is stationary, an additional friction braking device can be used.

[0049] Preferably, the rotor 3 has a thickness such that a skin effect (also called a film effect or Kelvin effect) is generated from each main surface 3.1, 3.2 of the rotor 3 over more than half the thickness of the rotor 3 at least over a range of possible relative speeds of the rotor 3 with respect to the stators 2. The eddy currents generated from the two main surfaces 3.1, 3.2 will then circulate in the central part of the rotor 3, which will increase the braking torque. This results in a "superposition of skin effects," the thickness of the rotor 1 being sufficiently small to achieve this effect while satisfying the thermal and mechanical constraints. In one example, this effect provides approximately 60% more performance.

[0050] In Figures 6 and 7, the mechanism comprises two intermediate parallelograms Pla, Pib, each sharing bars with one of the external parallelograms PEa, PEb, the central bars 8c being shared by the intermediate parallelograms Pla, Pib. Thus, the first parallelogram PEa comprises two end bars 9a, each having a first end connected to the end joint 7a and a second end connected by an intermediate joint 10a to a first end of a bar lia. The bars lia are connected at their midpoints by an intermediate joint 12a and each has a second end connected by an intermediate joint 13a to a first end of one of the central bars 8c. The second parallelogram PEb comprises two end bars 9b, each having a first end connected to the end joint 7b and a second end connected by an intermediate joint 10b to a first end of a bar 11b.The bars 11b are connected in their middle by an intermediate joint 12b and each has a second end connected by an intermediate joint 13b to a second end of one of the central bars 8c.

[0051] Alternatively, the braking device can be mixed magnetic / friction: the stators 2a, 2b in braking position have their main surface 2.1a, 2.1b applied against the main surfaces 3.1, 3.2 of the rotor 3 to produce a braking force by friction.

[0052] The rotors 3 are then preferably made of steel or cast iron such that their main surfaces 3.1, 3.2 can form braking surfaces. Any other electrically conductive material suitable for performing this function is usable. For example, the rotors 3 may comprise a copper disc whose main faces are covered with a layer of steel or cast iron to form the braking surfaces, which allows for a good coefficient of friction with the lining while increasing the heat mass so as to have effective braking despite the temperature increase caused by the friction of the lining on the braking surface.

[0053] In this mixed variant, the magnets 11, 12, 13, 14 have their surface, opposite the support 200, covered with an intermediate layer 201 itself covered with a friction lining 202 having, opposite the intermediate layer 201, a surface forming the face 2.1 of the stator 2 (see [Fig.9]). The intermediate layer 201, sandwiched between the magnets 11, 12, 13, 14 and the friction lining 202, is made of non-magnetic steel and has sufficient thickness to allow it to form a thermal shield between the friction lining 202 and the magnets 11, 12, 13, 14. The magnets will obviously be chosen to have a limited loss of magnetization at the operating temperatures of the magnetic braking device: in all cases, the Curie temperature of the magnets used must be much higher than the operating temperatures of the magnetic braking device regardless of the braking mode used.The intermediate layer 201 also protects the magnets from impacts and helps retain them on the support 200. The intermediate layer 201 can be screwed, riveted, or welded to the support 200 in such a way that the magnets are preferably trapped between the intermediate layer 201 and the support 200. These intermediate layers must be sufficiently thin to allow a small distance between the surfaces of the magnets and those of the rotor, thus enabling significant eddy current braking. It is preferable that they be used only for emergency braking because, being thin, they will wear out quickly.

[0054] The friction linings 202 are made of a non-magnetic material (to avoid creating a magnetic short circuit) and preferably an electrically insulating material (to limit losses during magnetic braking). The friction lining 202 is, for example, attached to the intermediate layer 201 by hot bonding or riveting. Such friction linings are known per se.

[0055] Preferably, the magnets of stator 2a are arranged to attract those of stator 2b and vice versa.

[0056] Magnetic braking is obtained as before by bringing the stators 2 close to the braking position without bringing the main surfaces 2.1a, 2.1b into contact with the main surfaces 3.1, 3.2.

[0057] It is understood that: - To induce friction braking, the actuators 5 are driven to bring the stators 2 into the maximum braking position (close position), a position in which the braking surfaces 2.1 are in contact with the braking surfaces 3.1, 3.2 and are held in this position by the magnets 11, 12, 13, 14 even in the absence of power supply. the actuator, and - to interrupt friction braking, the actuators 5 are controlled to bring the stators 2 to the second position, a position in which the braking surfaces 1.1, 1.2, 2.1 are no longer in contact with each other.

[0058] To ensure that the braking surfaces 2.1 are in contact with the braking surfaces 1.1, 1.2 and held together by magnetic attraction, a slight axial play may be provided between the actuator and / or the deformable parallelogram mechanism and the stators when the stators have been brought into their first position.

[0059] As an alternative to this mixed braking device, the device comprises first axial stops rotationally and translationally linked to the stators 2 and second axial stops rotationally and translationally linked to the rotor 3 to prevent contact between the faces 2.1 of the stators 2 and the faces 3.1, 3.2 of the rotor 3 when the stators 2 are in their maximum braking position. The axial stops comprise, for example, two pairs of rings, each fixed to an outer periphery of the rotors 1 and centered on the pivot axis, and each stator 2 also comprises a ring extending from an outer periphery of the support 200, surrounding the magnets 11, 12, 13, 14. Each ring has a flat annular end face extending perpendicularly to the pivot axis and is covered by a friction lining whose free surface forms a braking surface.It is understood that, when the stators 2 are in their close position, the braking surfaces of the rotor 3 are in contact with the braking surfaces of the stators 2, providing friction braking. It should be noted that in this position the main surfaces 3.1, 3.2 are not in contact with the faces 2.1a, 2.1b.

[0060] Otherwise, the operation is identical to that of the mixed braking device previously described.

[0061] Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0062] In particular, the device may have a different structure from that described.

[0063] The wheel may have a different structure from that described, be in one piece or on the contrary, in several pieces assembled together.

[0064] The braking device may include a different number of stators (for example one or more than two) and / or rotors (for example more than one).

[0065] Generally speaking, actuators can be electromechanical or hydraulic, single-acting or double-acting. For a single-acting actuator, the power supply enables the forward movement of the plunger, and an elastic element enables the plunger's return. The number of actuators can vary from the one mentioned. Preferably, at least three actuators symmetrically distributed around the wheel's axis of rotation will be used to balance the axial forces exerted on the stators.

[0066] A rim part (serving as a support for the tire) can be attached to a part of the rim and / or a part of the rim can be attached to a part of the hub.

[0067] Instead of being made up of two half-wheels, the wheel can be a single piece, made in a foundry or by additive manufacturing.

[0068] The veil can be continuous or discontinuous, and formed of one or more parts (plates or spokes for example).

[0069] Each half-wheel can be made of a material other than aluminum, for example magnesium, steel...

[0070] The rotor 3 is rotationally linked to the wheel 103 by any means, for example by means of axial bars in one piece with the rim or attached to it.

[0071] The magnets can be carried by the rotor instead of the stators.

[0072] There may be two rotors framing a stator, the stator being axially fixed by relative to the torsion tube and the rotors being axially mobile relative to the wheel. The actuators and deformable parallelogram mechanisms are then fixed to the wheel to axially move the rotors between a position away from the stator and a position closer to the stator.

[0073] The shape, arrangement, and dimensions of the magnets may differ from those described. For example, magnets 11, 12, 13, and 14 may not all have the same dimensions. Preferably, the first magnets 11 and 13 will represent approximately 70% of the surface area of ​​the element on which they are mounted, but this is not mandatory.

[0074] The use of a Halbach motif is not mandatory.

[0075] The magnetic braking device can be axial flux (the rotor and stator have only radial surfaces as their main surfaces), radial flux (the rotor and stator have only axial surfaces as their main surfaces) or combine axial and radial flux (the rotor and stator have axial and radial main surfaces).

[0076] The magnetic braking device can be combined with a conventional friction braking device that includes friction elements, for example a stack of carbon discs, and a plurality of electromechanical actuators mounted on an actuator holder. The braking device can be magnetic, friction, or a hybrid friction / magnetic system.

[0077] Each electromechanical actuator includes an electric motor and a pusher capable of being moved by the electric motor to press the stack of discs. The electromechanical actuator is thus designed to produce a controlled braking force on the stack of discs. A control mode for the braking devices is for example known from document FR-A-2953196.

[0078] The axial stops may have a different structure from that described. Axial stops linked in rotation and axial translation to the rotor may, for example, be separated from the rotors and fixed directly to the rim.

[0079] The actuator 5 is arranged to move one of the extreme joints 7a relative to the central joint 7c to cause a pivoting of the connecting rods of the deformable parallelograms resulting in an axial displacement of the external elements 2 relative to the central element 3. This action can be direct (the pusher is coupled to the clevis or the pivot of the extreme joint) or indirect (for example, the pusher is coupled to one of the stators itself coupled to the extreme joint).

[0080] The invention is usable on any type of vehicle having at least one wheel requiring braking, and for example aerial, land or amphibious vehicles, transport or industrial equipment.

Claims

Demands

1. A braked wheel (103) comprising a hub (104) for pivoting about a support shaft (102) defining an axis of rotation of the wheel, a rim (105) extending around the hub (104), a disc (106) connecting the rim (105) to the hub (104), and a braking device (1) comprising at least two external elements (2) fixed in rotation with respect to one of the shaft (102) and the rim (105), a central element (3) disposed between the external elements (2) and fixed in rotation with respect to the other of the shaft (102) and the rim (105), and at least one actuator (5) for axially moving the external elements (2) between a maximum braking position in which the external elements (2) are close to the central element (3) and a free rotation position in which the external elements (2) are away from the central element (3),characterized in that the external elements (2) are connected to each other by at least one deformable parallelogram mechanism (6) comprising at least two extreme joints (7a, 7b) each linked to one of the external elements (2) and a central joint (7c) fixed axially in translation, the actuator (5) being arranged to move one of the extreme joints (7a) relative to the central joint (7c) to cause a pivoting of the deformable parallelograms resulting in an axial displacement of the external elements (2) relative to the central element (3).

2. Wheel according to claim 1, wherein the mechanism comprises at least two external parallelograms (PEa, PEb) each having one of the extreme joints (7a, 7b) and which are linked together via two central bars (8c) having centers connected by the central joint (7c).

3. Wheel according to claim 2, wherein the central bars (8c) are shared by the external parallelograms (PEa, PEb).

4. Wheel according to claim 2, wherein the mechanism comprises two intermediate parallelograms (Pla, Pib) each sharing bars with one of the external parallelograms (PEa, PEb), the central bars (8c) being shared by the intermediate parallelograms (Pla, Pib).

5. A wheel according to any one of the preceding claims, wherein the external elements (2), the actuator (5) and the deformable parallelogram mechanism (6) are rotationally fixed relative to the shaft (102) and the central element (3) is fixed in rotation relative to the rim (105).

6. Wheel according to claim 5, wherein the braking device (1) comprises a torsion tube (4) which is rotationally linked to the shaft (102) and on which the external elements (2) are mounted to slide axially, the central articulation (7c) being fixed to the torsion tube (4).

7. Wheel according to any one of the preceding claims, wherein the braking device (1) is of the eddy current magnetic type, comprising magnets (11, 12, 13, 14) producing between the external elements (2) and central (3) an axial magnetic flux.

8. Wheel according to any one of claims 1 to 6, wherein the braking device (1) is of the friction type, the external and central elements comprising friction surfaces.

9. Lander (101) comprising a leg having an end carrying a shaft (102) on which is mounted the hub of a wheel (103), the element(s) (2, 3) of the braking device not rotationally linked to the wheel being rotationally linked to the leg.

10. Aircraft (100) comprising at least one landing gear (101) according to claim 9.

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