Vehicle wheel comprising drive device and brake device

Abstract

Disclosed is a vehicle wheel (1) rotatably mounted on an axle (E) and comprising:-an annular rim (2), a web (3) and a hub (4) delimiting a closed annular space,-an electric motor (10) comprising a first stator (11) and a first rotor (12) arranged coaxially with the wheel, and-a magnetic brake (20). Inside the annular space, the motor and the brake extend one within the other. Or the first rotor is used as a rotor of the brake (22), or the first stator (11) is used as a stator of the brake (21), in order to generate a second magnetic flux capable of inducing an eddy current generating a braking torque. Or the first stator or the first rotor is provided with a Halbach array which is at least partially formed by electromagnets.

Description

Technical Field

[0001] The present invention relates to braking and ground movement of vehicles, and more particularly to wheels including braking devices and drive devices. Background Technology

[0002] In the aviation field, it is now envisioned to equip aircraft wheels with rotary drive components to enable the aircraft to move on the ground without using its engines. It is also known to equip aircraft wheels with brakes intended to selectively decelerate and stop the aircraft as it moves on the ground. These brakes are typically friction brakes, which require replacement of worn components, and friction generates particularly polluting dust particles during braking.

[0003] However, in the case of electric vertical takeoff and landing (eVTOL) aircraft, the wheels are traditionally small (between 6 and 10 inches), making it very difficult to incorporate both the drive components and the brakes.

[0004] Furthermore, the landing gear of an eVTOL is typically fixed, unlike that of a larger aircraft which is movable between a retracted and extended position. Therefore, increasing the wheel size to accommodate drive components and brakes tends to increase drag on the landing gear during flight, and thus reduces the autonomy of the eVTOL in flight.

[0005] However, climate change is a major concern for many legislative and regulatory bodies around the world. Specifically, numerous countries have already implemented, are implementing, or will implement various restrictions on carbon emissions. In particular, a broad standard applies to both new and currently used aircraft, requiring the implementation of technological solutions to ensure compliance with existing regulations. The civil aviation industry has been mobilized for years to contribute to addressing climate change.

[0006] Technological research has yielded significant improvements in the environmental performance of aircraft. All stakeholders in the field are continuously striving to improve energy efficiency. The applicant has taken into account the influencing factors at all stages of design and development to obtain aircraft components and products that consume less energy, are more environmentally friendly, and have a milder environmental impact when integrated and used in civil aviation, with the aim of improving the energy efficiency of air transport.

[0007] Therefore, the applicant continuously strives to reduce its climate impact by using benign development and manufacturing methods and processes that minimize greenhouse gas emissions, thereby reducing the environmental footprint of its activities.

[0008] This ongoing research and development effort focuses on: next-generation aircraft engines; making aircraft lighter, particularly through the materials used and lighter onboard equipment; developing the use of electric technologies for propulsion; and aviation biofuels as a necessary complement to technological advancements. Summary of the Invention

[0009] Therefore, the object of the present invention is to provide a wheel that incorporates a drive mechanism and a braking mechanism, thereby at least partially eliminating the aforementioned disadvantages.

[0010] Therefore, the present invention provides a vehicle wheel rotatably mounted on an axle, the wheel comprising: - An annular rim, which is connected by spokes to a hub that is pivotally received on an axle, the rim and hub defining an annular space enclosed by the spokes; - A radial flux electric motor, the radial flux electric motor including a first stator and a first rotor, the first stator and the first rotor being arranged coaxially with a wheel so as to generate a first magnetic flux between them capable of generating a torque for driving the wheel to rotate; - Magnetic brake.

[0011] According to the present invention, within the annular space, the electric motor and the magnetic brake extend one inside the other. The first rotor also serves as the rotor of the magnetic brake, so as to generate a second magnetic flux with the stator of the magnetic brake capable of generating eddy currents that generate braking torque for the wheel, wherein the stator of the magnetic brake is arranged coaxially with the wheel, or The first stator also serves as the stator of a magnetic brake, so as to generate a second magnetic flux with the rotor of the magnetic brake that can generate eddy currents, which generate braking torque for the wheel, the rotor of the magnetic brake being arranged coaxially with the wheel.

[0012] This results in the radial superposition of the electric motor and the magnetic brake, and even the partial fusion of the electric motor and the magnetic brake, because the first rotor or first stator of the electric motor also serves as the active element of the magnetic brake.

[0013] The electric motor and magnetic brake are coupled together, one inside the other, and occupy a relatively small volume.

[0014] This makes it possible to incorporate an electric motor and magnetic brakes inside the wheel without significantly increasing the resistance against the wheel's movement.

[0015] Therefore, the present invention enables the association of both electric motors and magnetic brakes with aircraft wheels, even if the wheels are small in size.

[0016] Therefore, the mass of the components formed by electric motors and magnetic brakes is relatively low.

[0017] Furthermore, ground maintenance operations are thus simplified.

[0018] Advantageously, it is noted that, with the present invention, there is no need to provide an actuation system for the wheel to enable switching from the function of an electric motor to the function of a magnetic brake.

[0019] Optionally, one of the first rotors or the second rotor is adjacent to a rim, and the other of the first rotors and the second rotor is adjacent to a hub, with the first stator and the second stator extending between the first rotor and the second rotor.

[0020] Optionally, the first stator and the second stator face each other radially.

[0021] Optionally, the first stator extends inside the second stator.

[0022] Optionally, the first stator or the first rotor includes at least a portion of a Halbach array formed by electromagnets, and the first stator or the first rotor that includes the Halbach array also serves as a stator or the corresponding rotor of a magnetic brake.

[0023] Optionally, the first rotor includes a permanent magnet and / or an electromagnet capable of interacting with an electromagnet assembled to the first stator.

[0024] Optionally, the Halbach array is formed by a series of electromagnets extending circumferentially around the hub and / or axially along the hub.

[0025] Alternatively, the magnetic brake is a radial flux brake.

[0026] Optionally, the first stator is fixed to a support that is stationary relative to the wheel axle.

[0027] Alternatively, the second rotor is formed by a rim made of a conductive material, or by a partial coating made of a conductive material disposed on the inner periphery of the rim.

[0028] The present invention also relates to an aircraft landing gear, comprising at least one wheel as described above.

[0029] The present invention also relates to an aircraft comprising at least one landing gear as described above. Attached Figure Description

[0030] The invention will be better understood from the following description, which is purely illustrative and not restrictive, and should be read with reference to the accompanying drawings, in which: [ Figure 1 ] Figure 1 This is a simplified representation of an aircraft, which includes main landing gear, each of which is equipped with a wheel according to the invention; [ Figure 2 ] Figure 2 According to the first embodiment of the present invention Figure 1 An axial cross-sectional view of one of the wheels of the aircraft shown; [ Figure 3 ] Figure 3 yes Figure 2 A schematic diagram showing the cross-sectional arrangement of the wheels; [ Figure 4 ] Figure 4 It explains how magnetic flux can drive or brake. Figure 2 A schematic diagram of the wheel shown; [ Figure 5 ] Figure 5 This is according to the second embodiment of the present invention. Figure 1 An axial cross-sectional view of one of the wheels of the aircraft shown. Detailed Implementation

[0031] refer to Figure 1 The present invention is described as being applied to an electric vertical takeoff and landing (eVTOL) aircraft. For flight, landing, and takeoff, the aircraft A is equipped with at least one engine M.

[0032] Aircraft A includes two main landing gears P, each of which includes a strut J. The strut J has an upper end fixed to the upper structure S of the aircraft, and opposite to this upper end, a lower end supporting a wheel 1 that rotates about an axis X on an axle E. In this case, the landing gear P is fixed, but the invention is applicable to retractable landing gears, or even to another type of aircraft or another type of vehicle, such as a land vehicle.

[0033] In the first embodiment, Figure 2 As shown, wheel 1 includes an annular rim 2, which is connected to hub 4 via spokes 3. Hub 4 is pivotally received on axle E by means of bearings 5 ​​and 6. The rim 2 extends coaxially around hub 4 and, together with hub 4, defines an annular space having one end at least partially closed by spokes 3, and the opposite end being an open end. Rim 2 and hub 4 thus extend coaxially along axis X.

[0034] Wheel 1 is referred to as "motorized," meaning it is equipped with a drive unit intended to move aircraft A without using its engines when aircraft A is on the ground.

[0035] The drive unit includes a radial flux electric motor 10, which comprises a first stationary element or stator 11 and a first rotatable element or rotor 12 in a manner known per se. The stator 11 and rotor 12 each have a central axis coinciding with axis X (axis X is therefore the axis of rotation of wheel 1). The stator 11 and rotor 12 thus extend coaxially with axis X. The stator 11 and rotor 12 thus extend coaxially with rim 2 and hub 4.

[0036] In addition, the rotor 12 extends radially toward the stator 11.

[0037] Alternatively, the rotor 12 extends inside the stator 11.

[0038] The wheel also has a support member 30 integral with the axle E. For example, the support member is formed as a plate. For example, the support member extends coaxially with the hub 4.

[0039] Optionally, the stator 11 is fixedly mounted on the support 30. The stator 11 is therefore stationary relative to the support 30, and thus stationary relative to the axle E.

[0040] In this case, the stator 11 is in the form of a ring.

[0041] The stator 11 thus has an outer circumferential surface (forming an outer main surface 11.1), an inner circumferential surface (forming an inner main surface 11.2), a first lateral ventral surface connecting the two circumferential surfaces, and a second lateral ventral surface connecting the other two circumferential surfaces (opposite to the first lateral ventral surface and optionally parallel to the first lateral ventral surface).

[0042] The first lateral ventral surface is the one fixed to the planar support 30. The second lateral ventral surface faces the spoke 3. The main surface 11.1 faces the rim 2. The main surface 11.2 faces the rotor 12.

[0043] In this configuration, the rotor 12 is ring-shaped. The rotor 12 is fixedly mounted on the spokes 3, such that the rotor 12 is stationary relative to the wheel 1. The rotor 12 includes a series of permanent magnets (not shown). These permanent magnets are, for example, arranged to have alternating north and south poles on the same main surface 12.1 of the rotor 12, which faces the main surface 11.2 of the stator 11.

[0044] Wheel 1 is also referred to as "braking," meaning it is equipped with a braking device intended to selectively decelerate aircraft A when it is on the ground.

[0045] The braking device includes a radial flux brake 20 and, in a manner known per se, a second stationary element or stator 21 and a second rotatable element or rotor 22.

[0046] The stator 21 and rotor 22 each have a central axis that coincides with the rotation axis X of the wheel 1. The stator 21 and rotor 22 extend coaxially from the hub 4.

[0047] In this case, stator 21 is formed directly from stator 11 of electric motor 10. In the following text, only stator 11 will be referred to, which is therefore also stator 21.

[0048] The stator 11 and the rotor 22 extend radially toward each other. In this case, the stator 11 extends inside the rotor 22.

[0049] The stator 11 includes a series of electromagnets (not shown). These electromagnets are arranged to form a Halbach array.

[0050] For the purposes of this application, a Halbach array is a specific arrangement of aligned permanent magnets that increases the magnetic field on one side of the alignment while almost completely eliminating the magnetic field on the other side. This is achieved by rotating the magnetic field orientation on a series of aligned magnets (for the same aligned surface, the permanent magnets are arranged as follows: North pole on the left, North pole up, North pole on the right and North pole down; North pole on the left, North pole up, North pole on the right and North pole down, etc.).

[0051] In this case, by means of the arrangement of the stator 11, the electromagnet forms both the outer main surface 11.1 and the inner main surface 11.2 of the stator 11.

[0052] like Figure 3 As schematically shown, on the main surface 11.1 of the stator 11, electromagnets are arranged such that they can be continuously found in the circumferential direction: - North pole electromagnet 31 (i.e., the north pole of electromagnet 31 faces the rotor 22; it can be inferred from this that the south pole of the same electromagnet 31 faces the rotor 12). - East Pole Electromagnet 32 ​​(i.e., the north pole of Electromagnet 32 ​​is oriented to the right of the north pole of North Pole Electromagnet 31). - South pole electromagnet 33 (i.e., the north pole of electromagnet 33 faces the rotor 12; it can be inferred from this that the south pole of the same electromagnet 33 faces the rotor 22). - West pole electromagnet 34 (i.e., the north pole of electromagnet 34 is oriented to the left of the north pole of electromagnet 31). This continuous arrangement of four electromagnets extends around the stator 11 throughout its entire length.

[0053] In this case, the rotor 22 is formed directly from the rim 2. For example, the rim 2 is made of a conductive material (e.g., aluminum, steel, etc.). The rim 2 includes an inner periphery that defines the main surface 22.1 of the rotor 22, which is separated from the main surface 11.1 of the stator 11 by a predetermined air gap e. Therefore, it is understood that the rotor 22 is stationary relative to the wheel 1.

[0054] Therefore, it should be noted that the same stator is used for both the electric motor 10 and the braking device 20; in use, depending on the direction of the current flow through the electromagnet, the stator 11 can indeed be used to rotate the wheel 1 or to brake the same wheel 1.

[0055] It is understood that, on the one hand, the air gaps between stator 11 and rotor 22, and between stator 11 and rotor 12, must be kept small so that the electric motor 10 and braking device 20 can operate efficiently. Since rotor 22 is formed by rim 2, in this case, it forcibly defines the positioning of stator 11 (relative to air gap e), which in turn forcibly defines the positioning of rotor 12 (relative to air gap e' existing between rotor 12 and stator 11). Therefore, rotor 12 is fixed to spoke 3 at a predetermined distance from axis X. In this case, it is noted that rotor 12 is closer to stator 11 than axle E. Rotor 12 thus defines an internal sub-volume together with axle E, which can accommodate one or more other components (reduction gearbox, sensors, etc.).

[0056] The permanent magnets of rotor 12 are thus able to interact with the electromagnets mounted to stator 11 to generate a first magnetic flux that drives rotor 12 and thus the wheel 1 to rotate about axis X. Specifically, when the electromagnets mounted to stator 11 are energized by current flowing in a first direction, they generate a sufficient magnetic field to generate torque for driving hub 4 and thus the wheel 1 to rotate by interacting with a series of permanent magnets mounted to rotor 12.

[0057] Furthermore, when the electromagnets are energized by a current flowing in a second direction (opposite to the first flow direction) and the wheel 1 rotates about its axis of rotation X, the electromagnets of the stator 11 are arranged to generate a second magnetic flux, which in turn generates eddy currents in the rim 2. Specifically, when the electromagnets assembled to the stator 11 are energized by a current, they generate eddy currents in the rotor 22 sufficient to generate braking torque on the rotor 22 and thus on the wheel 1.

[0058] refer to Figure 4 The electromagnets of stator 11, which form the Halbach array, are therefore configured as follows: - For the first current flow direction, the portion of the first magnetic flux 23 seen by the electric motor 10 is maximized, and the portion of the first magnetic flux sent to the rim is maximized and limited (or even eliminated). - For the second current flow direction, the portion of the second magnetic flux 24 seen by the rim 2 is maximized, and the portion of the second magnetic flux sent to the electric motor 10 is maximized and restricted (or even eliminated).

[0059] Preferably, the stator 11 is configured such that the Halbach array is fixed in position for the direction of the second current flow; in other words, the different poles of the electromagnets do not interchange when the magnetic brake 20 is used. Therefore, during braking, only the magnitude of the second magnetic flux can vary (depending on the intensity of the current flowing through the stator 11).

[0060] Preferably, the stator 11 is configured such that the Halbach array is not fixed in position for the direction of the first current flow. Preferably, when the electric motor 10 is used, only the east pole electromagnet and the west pole electromagnet (by being placed at the level of the main surface 11.2 of the stator 11) remain frozen in position. On the other hand, the north pole electromagnet and the south pole electromagnet (by being placed at the level of the main surface 11.2 of the stator 11) are electrically controlled so that they can be interchanged as south pole electromagnet and north pole electromagnet respectively at regular time intervals. Therefore, not only the magnitude of the first magnetic flux can be changed (depending on the intensity of the current flowing through the stator 11), but also its direction can be changed. Thus, by controlling the north pole electromagnet and the south pole electromagnet, relative rotational motion between the rotor 12 and the stator 11 can be induced.

[0061] Therefore, the electric motor 10 and the magnetic brake 20 operate independently of each other, but use common components.

[0062] This makes the electric motor 10 and magnetic brake 20 assembly particularly compact and lightweight. In particular, the electric motor 10 and magnetic brake 20 extend integrally within the annular space defined by the wheel 1.

[0063] It should also be noted that using rim 2 as a radiator and conductor of eddies together contributes to making the component more compact and lighter.

[0064] Furthermore, because the electric motor 10 and the magnetic brake 20 extend integrally within the annular space defined by the wheel 1, the drag applied to the landing gear P is limited, especially since the landing gear P is non-retractable. This arrangement of the electric motor 10 and the magnetic brake 20 thus limits the aerodynamic effects of the landing gear P.

[0065] It will also be noted that this arrangement of the electric motor 10 and the magnetic brake 20 makes it possible to simplify the integration of the drive and braking devices while maintaining sufficient performance.

[0066] refer to Figure 5 The second embodiment will now be described.

[0067] The second embodiment is the same as the first embodiment, except that the rotor 12 is not fixedly mounted to the spokes 3, but is fixedly mounted on the outer periphery 36 of the hub 4. The outer periphery 36 of the hub 4 extends coaxially with the axle E and / or the axis X. The outer periphery 36 of the hub 4 therefore extends radially facing the rotor 12.

[0068] Therefore, it can be understood that rotor 12 is stationary relative to wheel 1.

[0069] To comply with sufficiently low air gap values ​​e and e' for proper operation of the braking device and motor 10, rotor 12 can be directly fixed to hub 4, or it can be fixed to hub 4 by means of additional component 37.

[0070] Of course, the present invention is not limited to the embodiments described, but includes any variations that fall within the scope of the present invention, such as those defined in the claims.

[0071] Wheel 1 may have a structure different from that described. The rim 2 of wheel 1 may, for example, be formed from two half rims, be manufactured as a single piece, be made in a foundry, or be manufactured by additive manufacturing, etc.

[0072] Materials different from those indicated may be used.

[0073] Although the rim 2 forms the rotor 22 of the magnetic brake 20 in this case, the rim 2 may also have a partial coating (e.g., made of copper, aluminum, silver, nickel, etc.) on its inner periphery that forms the rotor 22. The rim 2 may then be made of a material different from the coating material.

[0074] The stator 11 does not need to be mounted to the axle E (directly or by means of a support), but must be mounted to another part of the aircraft and (directly or by means of a support) to one of its landing gears.

[0075] The arrangement of the electric motor 10 and the magnetic brake 20 can be reversed. In other words, the stator 11 and rotor 12 of the electric motor 10 can replace the stator 21 and rotor 22 of the magnetic brake 20, respectively, and vice versa.

[0076] The permanent magnet can be carried by the stator 11 instead of the rotor 12. The electromagnet can be carried by the rotor 22 instead of the stator 21. Therefore, it is understood that the rotors 12 and 22 of the electric motor 10 and the braking device 20 are combined, while the stators 11 and 21 are separate.

[0077] The drive unit may further include a reduction gear for increasing the drive torque delivered to the wheel 1 by the electric motor 10. The reduction gear can be of any type: planetary reduction gear, harmonic reduction gear, cycloidal reduction gear, etc. Such a reduction gear can therefore be arranged between the rotor 12 and the wheel 1. For example, the rotor 12 can be fixedly mounted to the reduction gear, which itself will be fixedly mounted to the spokes 3 and / or the hub 4. For example, the reduction gear can therefore be... Figure 5 Additional component 37 is shown.

[0078] Although the rotor 12 of the electric motor 10 here includes only permanent magnets, for example to form a synchronous motor, it may also include electromagnets, for example to form an asynchronous motor. Regardless of whether the rotor 12 carries electromagnets and / or permanent magnets, the electromagnets and / or the permanent magnets may optionally be arranged to form a Halbach array.

[0079] Although the stator 21 of the magnetic brake 20 comprises only electromagnets in this case, it may also include permanent magnets. In particular, the electromagnets and permanent magnets of the magnetic brake 20 may be arranged to form a Halbach array, such that (for the main surface of the stator 21) the permanent magnets have alternating north and south poles, and the electromagnets have alternating east and west poles, for the electromagnets to follow the permanent magnets in at least one circumferential direction and / or one axial direction.

[0080] Although in this case the rotor 22 of the magnetic brake 20 is formed by the rim 2 or by a partial coating provided on the inner periphery of the rim 2, it may also be formed by any element directly or indirectly attached to the rim 2.

[0081] The arrangement and number of bearings 5 ​​and 6 that ensure wheel 1 rotates around axis X may differ from the arrangement and number described and illustrated.

[0082] At least one bearing may be arranged between the rim 2 and the support 30 and / or the stator 11. For example, at least one bearing may be arranged between the rim 2 and the support 30 and / or the stator 11 to ensure a constant air gap e between the main surface 11.1 of the stator 11 and the main surface 22.1 of the rotor 22, so that the braking torque applied by the magnetic brake 20 is constant (in a manner known per se, the braking torque is a function of the air gap e).

[0083] At least one bearing may be arranged between the stator 11 and the rotor 12. For example, at least one bearing may be arranged between the stator 11 and the rotor 12 to ensure a constant air gap e' between the main surface 11.2 of the stator 11 and the main surface 12.1 of the rotor 12, so that the torque applied by the electric motor 10 is constant (in a manner known per se, the torque is a function of the air gap e').

[0084] The number of stators (11, 21) and / or rotors (12, 22) may differ from the number described.

[0085] This invention is applicable to other types of eddy current brakes, particularly eddy current brakes with axial flow or a combination of axial and radial flow.

[0086] This invention can be used in any type of transportation, whether it is an airborne (aircraft, airplane, helicopter, UAM, eVTOL, etc.) or a land or amphibious vehicle.

[0087] This invention can be used in applications other than vehicles, for example, for any industrial or personal equipment that requires braking.

[0088] Although in this case the stator ring is formed by a single electromagnet ring (the electromagnets extend continuously in the circumferential direction in the following order: North Pole Electromagnet, East Pole Electromagnet, South Pole Electromagnet, West Pole Electromagnet), the stator ring can be formed by at least two electromagnet rings that extend continuously along the X-axis (it is known that for each ring, the electromagnets then extend continuously in the circumferential direction in the following order: North Pole Electromagnet, East Pole Electromagnet, South Pole Electromagnet, West Pole Electromagnet).

Claims

1. A vehicle wheel (1), rotatably mounted on an axle (E), comprising: - An annular rim (2), the rim (2) being connected by spokes (3) to a hub (4) pivotally received on the axle, the rim and the hub defining an annular space enclosed by the spokes; - A radial flux electric motor (10) comprising a first stator (11) and a first rotor (12) arranged coaxially with the wheel to generate a first magnetic flux between them capable of generating a torque for driving the wheel to rotate; - Magnetic brake (20); The characteristic feature is that, within the annular space, the electric motor and the magnetic brake extend one inside the other. The first rotor (12) also serves as the rotor of the magnetic brake, so as to generate a second magnetic flux with the stator of the magnetic brake capable of generating eddy currents that generate braking torque for the wheel, wherein the stator of the magnetic brake is therefore arranged coaxially with the wheel (1), or The first stator (11) also serves as the stator of the magnetic brake, so as to generate a second magnetic flux with the rotor of the magnetic brake capable of generating eddy currents, which generate braking torque for the wheel, wherein the rotor of the magnetic brake is therefore arranged coaxially with the wheel (1). The first stator (11) or the first rotor (12) includes at least a portion of a Halbach array formed by electromagnets, and the first stator (11) or the first rotor (12) that includes the Halbach array also serves as the stator or corresponding rotor of the magnetic brake.

2. The wheel according to claim 1, characterized in that, One of the first rotor or the second rotor is adjacent to the rim (2), and the other of the first rotor and the second rotor is adjacent to the hub (4), with the first stator (11) and the second stator extending between the first rotor (12) and the second rotor.

3. The wheel (1) according to claim 1 or 2, characterized in that, The first stator (11) and the second stator face each other radially.

4. The wheel (1) according to claim 3, characterized in that, The first stator (11) extends inside the second stator.

5. The wheel (1) according to any one of the preceding claims, characterized in that, The first rotor (12) includes a permanent magnet and / or an electromagnet capable of interacting with an electromagnet assembled to the first stator (11).

6. The wheel (1) according to claim 5, characterized in that, The Halbach array is formed by a continuous electromagnet extending circumferentially around the hub (4) and / or axially along the hub (4).

7. The wheel (1) according to any one of the preceding claims, characterized in that, The second rotor is formed by the rim (2) made of conductive material, or by a partial coating made of conductive material disposed on the inner periphery of the rim (2).

8. A landing gear (P) for an aircraft (A), comprising at least one wheel (1) according to any one of the preceding claims.

9. An aircraft (A) comprising at least one landing gear (P) according to claim 8.

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