Vehicle wheel including a drive device integrated into the wheel, aircraft landing gear and aircraft equipped with such a wheel

Abstract

A vehicle wheel (10) comprising a hub (13) rotatably mounted on an axle (E, E'), a rim (11) defining an annular space (20) with the hub, and a drive device (100, 100') for rotating the wheel relative to the axle, the rotational drive device being housed within the annular space defined by said wheel. An aircraft landing gear (2) and an aircraft (1) equipped with such a wheel. ABBREVIATED FIGURE: Fig. 2A

Description

Title of the invention: Vehicle wheel comprising a drive device integrated into the wheel, aircraft landing gear and aircraft equipped with such a wheel

[0001] The present invention relates to the movement of a vehicle on the ground, and more particularly to running gear comprising a shaft or axle, a wheel pivotally mounted on the shaft and a device for driving the wheel in rotation relative to the shaft. The invention also relates to an aircraft landing gear and an aircraft equipped with such running gear.

[0002] BACKGROUND OF THE INVENTION

[0003] In the field of aviation, it is now planned to equip aircraft with devices for rotating the wheels to enable the aircraft to be moved on the ground without using its powertrains.

[0004] An aircraft wheel generally comprises a rim connected by a web to a hub which is mounted for rotation on a shaft or axle carried by a lower end of a landing gear.

[0005] In the case of electric vertical take-off and landing aircraft (eVTOL), it has been considered to mount such devices next to the wheels.

[0006] However, the landing gear of eADAVs is generally fixed, i.e. not movable between a retracted position and a deployed position as is the case for airliners. Increasing the size of the wheels to integrate drive devices would therefore tend to increase the drag forces exerted on the landing gear during flight, and therefore the energy consumption of the eADAV in flight.

[0007] However, climate change is a major concern for many legislative and regulatory bodies around the world. Indeed, various restrictions on carbon emissions have been, are being or will be adopted by various states. In particular, an ambitious standard applies both to new types of aircraft and those currently in circulation requiring the implementation of technological solutions in order to make them compliant with current regulations. Civil aviation has been mobilizing for several years now to make a contribution to the fight against climate change.

[0008] Technological research efforts have already made it possible to significantly improve the environmental performance of aircraft. All stakeholders in the sector are constantly working to improve energy efficiency. The Applicant takes into consideration the impacting 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.

[0009] Consequently, the Applicant is constantly working to reduce its climate impact by using methods and operating virtuous development and manufacturing processes and minimizing greenhouse gas emissions to the minimum possible in order to reduce the environmental footprint of its activity.

[0010] This sustained research and development work covers new generations of aircraft engines, the lightening of aircraft, particularly through the materials used and lighter on-board equipment, the development of the use of electrical technologies to ensure propulsion, and, as essential complements to technological progress, aeronautical biofuels.

[0011] SUBJECT OF THE INVENTION

[0012] The invention results from this work and aims to propose a running gear for a vehicle making it possible to at least partially overcome the aforementioned drawbacks. Summary of the invention

[0013] For this purpose, a vehicle wheel is provided comprising a hub rotatably mounted on an axle, a rim defining with the hub an annular space, and a device for driving the wheel in rotation relative to the axle. According to the invention, the rotational drive device is housed inside the annular space defined by said wheel.

[0014] The integration of a drive device in the space available inside the wheel makes it possible to limit the drag forces which oppose the movement of said wheel.

[0015] Preferably, the drive device defines a force transmission chain comprising a bell which has an end for connection to the axle and which is engaged in the annular space so as to also form a cowling of at least a part of the drive device.

[0016] Thus, the bell participates in the transmission of movement between the axle and the wheel while ensuring a function of protecting the drive device, for example against impacts or the introduction of foreign bodies into said drive device.

[0017] According to a particular characteristic of the invention, the drive device comprises an electric motor.

[0018] In particular, the electric motor is radial flux.

[0019] In particular, the electric motor is radial flux and comprises a stator and a rotor extending inside said stator.

[0020] In particular, the electric motor is radial flux and comprises a stator and a rotor extending around said stator.

[0021] According to another particular characteristic of the invention, the drive device comprises a reducer, one output of which is rotationally linked to the wheel.

[0022] In particular, the reducer is a planetary reducer.

[0023] In particular, the reducer is a multi-stage reducer.

[0024] The invention also relates to an aircraft landing gear comprising an end comprising an axle on which such a wheel is rotatably mounted.

[0025] The invention further relates to an aircraft comprising at least one such landing gear. Brief description of the drawings

[0026] The invention will be better understood in light of the following description, which is purely illustrative and non-limiting, and must be read in conjunction with the appended drawings, among which:

[0027] [Fig-1] [Fig.l] is a simplified representation of an aircraft comprising landings- main risers each equipped with a motorized wheel;

[0028] [Fig.2A] [Fig.2A] is an axial sectional view of one of the motorized wheels of the aircraft illustrated in [Fig.1], according to a particular embodiment of the invention;

[0029] [Fig.2B] [Fig.2B] is a view identical to [Fig.2A], illustrating a variant of the drive device of the motorized wheel illustrated in [Fig.2A]; DETAILED DESCRIPTION OF THE INVENTION

[0030] With reference to [Fig. 1], the invention is described in application to an electric vertical take-off and landing (eVOTL) aircraft 1. The aircraft 1 comprises two main landing gears 2, each comprising a leg 3 which has an upper end fixed to a structure 4 of the aircraft and, opposite, a lower end carrying a wheel 10 rotating about an axis X on a tubular axle E (visible in FIGS. 2A and 2B). The landing gears 2 are fixed here, but the invention is applicable to retractable type landing gears, or even to another type of aircraft or vehicle such as a land vehicle.

[0031] With reference to [Fig.2A], the wheel 10 comprises a main part 10.1 and an auxiliary part 10.2 attached to the main part 10.1, these parts both being of generally annular shape.

[0032] The main part 10.1 comprises an annular rim 11 connected by a web 12 to a hub 13 pivotally received on an end portion of the axle E by means of a first bearing 14.1 and a second bearing 14.2. The rim 11 extends coaxially around the hub 13 and delimits with said hub 13 an annular space 20 having one end at least partially closed by the veil 12 and, opposite, an open end.

[0033] The hub 13 has a first end comprising a first bore 13.1 in which the first bearing 14.1 is received, and a second end, opposite the first end, comprising a second bore 13.2 in which the second bearing 14.2 is received.

[0034] The rim 11 comprises a free end shaped into a first bead 15.1 and, at the opposite, a centering surface of the auxiliary part 10.2. The auxiliary part 10.2 has one end shaped into a second bead 15.2. In a manner known per se, the auxiliary part 10.2 is attached to the main part 10.1 after placing a tire (not shown) on the rim 11. A bead 16 is interposed between the main part 10.1 and the auxiliary part 10.2 to secure these two parts together.

[0035] The wheel 10 is said to be “motorized”, that is to say equipped with a rotational drive device 100 intended to move the aircraft 1 without using its powertrains when the latter is on the ground.

[0036] According to a particular embodiment of the invention, the drive device 100 extends inside the annular space 20, and comprises a radial flux electric motor 110 and a two-stage reducer 120 making it possible to increase the drive torque delivered to the wheel 10 by the electric motor 110.

[0037] In a manner known per se, the electric motor 110 comprises a fixed element or stator 111, and a rotating element or rotor 112. The stator 111 and the rotor 112 here each have a central axis coincident with the axis X of rotation of the wheel 10, the stator 111 extending inside the rotor 112.

[0038] The stator 111 here has the form of a crown mounted fixedly on an external periphery of an annular support 113 which is itself mounted on the axle E between a shoulder of said axle E and an inner ring of the first bearing 14.1.

[0039] The annular support 113 comprises an internal periphery provided with grooves cooperating with homologous grooves arranged on an external periphery of the axle E to ensure a rotational coupling, around the axis X, of the annular support 113 and therefore of the stator 111 with said axle E. The annular support 113 is held in abutment against the shoulder of the axle E via a retaining nut 17 in abutment against an inner ring of the second bearing 14.2, so that the annular support 113 and therefore the stator 111 are fixed with respect to the axle E.

[0040] The stator 111 comprises a pack of laminations 111a forming a plurality of teeth which extend radially around the axis X and on which windings 111b are wound.

[0041] The rotor 112 is mounted to rotate about the axis X on the hub 13 of the wheel 10 by means of a bearing 114, and comprises an annular portion 112a of large diameter connected to a small diameter annular portion 112b by a web 112c. The large diameter annular portion 112a and the small diameter annular portion 112b are cylindrical in shape and extend on either side of the web 112c, around the axis X. The large diameter annular portion 112a extends around the stator 111 and comprises an internal periphery provided with a series of magnets 112d capable of interacting with the windings 111b carried by said stator 111 to drive the rotor 112 in rotation around the axis X. The small diameter annular portion 112b comprises an internal periphery cooperating with an external bearing surface of the bearing 114.

[0042] The reducer 120 is a two-stage planetary reducer. Each of these stages comprises four satellites 121.1, 121.2 mounted in the same planet carrier 122.1, 122.2. The satellites 121.1, 121.2 mesh simultaneously with an internal or planetary pinion 123.1, 123.2 and with an external crown 125a common to both stages.

[0043] Each of the planet carriers 122.1, 122.2 comprises two circular plates which extend perpendicular to the X axis and which are connected by pads 126.1, 126.2 on which the satellites 121.1, 121.2 rotate around an axis parallel to the X axis by means of a bearing 127.1, 127.2.

[0044] The sun gear 123.1 of the first stage is constituted by the small diameter annular portion 112b of the rotor 112 which comprises an external periphery provided with teeth distributed angularly in a regular manner around the axis X: the sun gear 123.1 is part of the rotor 112 and is mounted to move in rotation on the hub 13 of the wheel 10 by means of the bearing 114.

[0045] The planet carrier 122.1 of the first stage has an extension provided with external teeth forming the sun gear 123.2 of the second stage: the sun gear 123.2 of the second stage is part of the planet carrier 122.1 of the first stage and is mounted to rotate on the hub 13 of the wheel 10 by means of a bearing 124 of axis X. The planet carrier 122.2 of the second stage has an extension which comprises splines cooperating with homologous splines arranged on an external periphery of the hub 13 to ensure rotational coupling of said planet carrier 122.2 with said hub 13 around the axis X. The small diameter annular portion 112b of the rotor 112 and the extension of the planet carrier 122.2 respectively form an input shaft and an output shaft of the reducer 120.

[0046] It will be noted that by associating several functions within the electric motor 110 and the reducer 120 in the same part, the drive device 100 is particularly compact and lightweight.

[0047] The crown 125a extends around the planet carriers 122.1, 122.2, coaxially with the axis X, and comprises a free end provided with internal teeth meshing with the planets 121.1, 121.2 of each of the stages of the reducer 120.

[0048] The outer ring 125a is formed by a free edge of a bell 125 having an opposite edge connected by a web 125b to the axle E to form a connecting end of the bell 125 to said axle E. More precisely, the web 125b is bolted to an axle hand EB so that said bell 125 is, like the stator 111, fixed with respect to said axle E. The bell 125 extends around the electric motor 110 and extends opposite the rim 11. The bell 125 thus forms a cover which protects the electric motor 110 and the rest of the reducer 120 from external aggressions by forming a protective casing. Therefore, the bell 125 provides a dual function: it is part of the force transmission chain of the drive device 100 and it protects said drive device 100.

[0049] It is understood that the fact that the drive device 100 extends inside the wheel 10 limits the drag forces exerted on the undercarriage 2, in particular during the flight phases, and this is all the more so since said undercarriage 2 is not retractable here. Such an arrangement of the drive device 100 thus limits the aerodynamic impact of the undercarriage 2.

[0050] [Fig.2B] illustrates a drive device 100' which is none other than a variant of the drive device 100 illustrated in [Fig.2A]. The drive device 100' extends in the annular space 20 delimited by the wheel 10, and comprises a radial flux electric motor 110' and a two-stage reducer 120' making it possible to increase the drive torque delivered to the wheel 10 by the electric motor 110'.

[0051] The electric motor 110' comprises a stator 111' and a rotor 112' which here each have a central axis coincident with the axis X of rotation of the wheel 10. The rotor 112' extends inside the stator 111'.

[0052] The stator 111' here has the form of a crown mounted fixed on an internal periphery of a bell 113' which is itself fixed to an axle support hand Ef. The stator 111' comprises a pack of sheets 111a' forming a plurality of teeth which extend radially towards the axis X and on which windings 111b' are wound.

[0053] The bell 113' comprises an annular portion 113a' having one end from which extends a web 113b' bolted to the axle support bracket Ef, so that said bell 113' and therefore the stator 111' are fixed with respect to the axle E'. The annular portion 113a' of the bell 113' extends opposite the rim 11. The bell 113' then performs a triple function: it is part of the force transmission chain of the drive device, it carries the stator 111' and it protects the drive device 100' against impacts and the introduction of foreign bodies into it.

[0054] The rotor 112' is tubular in shape and extends around the hub 13 of the wheel 10. The rotor 112' is mounted to rotate on said hub 13 by means of two bearings 114' of axis X and comprises a first end comprising a circumference external provided with a series of magnets 112d' capable of interacting with the windings 111b' carried by said stator 111' to drive the rotor 112' in rotation around the axis X.

[0055] The 120' reducer is a two-stage planetary reducer.

[0056] The first stage comprises four satellites 121.1' meshing simultaneously with an internal or planetary pinion 123.1' and with a first external crown 125.1'. The sun gear 123.1' of the first stage is constituted by a second end of the rotor 112' having an external periphery provided with teeth distributed angularly in a regular manner around the axis X: the sun gear 123.1' is part of the rotor 112' and is mounted to rotate on the hub 13 of the wheel 10 by means of the bearings 114' of axis X. The first outer ring gear 125.1' is constituted by the bell 113' whose annular portion 113a' comprises a free end provided with internal teeth meshing with the satellites 121.1' of the first stage: the first outer ring gear 125.1' is part of the bell 113' and is fixed with respect to the axle E'.

[0057] The second stage comprises four satellites 121.2' meshing with a second outer ring 125.2' which is bolted to the disc 12 of the wheel 10. Each of the satellites 121.2' of the second stage is secured to one of the satellites 121.1' of the first stage. It will be noted that the satellites 121.2' of the second stage have a diameter smaller than that of the satellites 121.1' of the first stage.

[0058] The satellites 121.1', 121.2' are mounted in the same satellite carrier 122' comprising two circular plates which extend perpendicular to the axis X and which are connected by pads 126' on which the satellites 121.1', 121.2' rotate around an axis parallel to the axis X by means of a bearing 127.1', 127.2'.

[0059] The rotor 112' and the second outer ring 125.2' respectively form an input shaft and an output shaft of the reducer 120'.

[0060] As for the drive device 100, it will be noted that by associating several functions within the electric motor 110' and the reducer 120' in the same part, the drive device 100' is particularly compact and lightweight.

[0061] The first outer ring 125.1' and the second outer ring 125.2' extend radially opposite the rim 11, in the extension of one another, and protect the electric motor 110' and the rest of the reducer 120' from external aggression by forming a protective casing.

[0062] It is understood that the fact that the drive device 100' extends inside the wheel 10 limits the drag forces exerted on the undercarriage 2, in particular during the flight phases, and this is all the more so since said undercarriage 2 is not retractable here. Such an arrangement of the drive device 100' thus limits the aerodynamic impact of the undercarriage 2.

[0063] During the deceleration phases, the electric motor 110, 110' can be used as a generator to produce electrical energy and, for example, recharge batteries powering said electric motor 110, 110'.

[0064] It will also be noted that the drive devices 100, 100': • are electrically powered independently of the aircraft's powertrains 1; • can be easily added or removed from the axle E, E' which simplifies the assembly and maintenance operations of the landing gear 2; • allow the wheel 10 to rotate freely when the electric motor 110, 110' is not in operation, or even broken down; • allow aircraft 1 to be moved on the ground without using its power units; and • allow wheel 10 to be rotated before aircraft 1 touches the ground in order to minimize tire wear when aircraft 1 moves forward during landing.

[0065] 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.

[0066] The wheel 10 may have a structure different from that described. The rim 11 of the wheel 10 may, for example, be formed from two half-rims, be made in a single piece, made in a foundry or by additive manufacturing, etc.

[0067] Although the motor 110, 110' is electric here, it can be of another type (hydraulic, pneumatic, thermal, etc.).

[0068] Although here the electric motor 110, 110' is radial flux, it can also be axial flux.

[0069] Although here the stator 111 of the electric motor 110 extends inside the rotor 112, the rotor 112 can, conversely, extend inside the stator 111.

[0070] Although here the rotor 112' of the electric motor 110, 110' extends inside the stator 111', the stator 111' can, conversely, extend inside the rotor 112'.

[0071] The electric motor 110, 110' may be of the "pancake" type, i.e. wide and flat and having rapid acceleration and deceleration using a high number of pole pairs.

[0072] The electric motor 110, 110' and the reducer 120, 120' can be replaced by a geared motor.

[0073] The reducer 120, 120' is optional.

[0074] The magnets 112d, 112d' may be carried by the stator 111, 111' instead of the rotor 112, 112'.

[0075] Although the planetary reducer 120, 120' is here two-stage, it can comprise a single stage or a number of stages greater than two.

[0076] The reducer 120, 120' may be of a type other than that described. The reducer may for example be a cycloidal reducer, a stepped planetary reducer, a strain wave reducer...

[0077] The number of satellites 121.1, 121.2, 121.1', 121.2' may be greater or less than four.

[0078] The invention can be used on any type of vehicle, air, land or amphibious, or any industrial or transport mobile equipment requiring braking.

[0079] Although the tubular axle E, E' is here of generally cylindrical shape, it can also be conical.

Claims

Claims

1. Vehicle wheel (10), comprising a hub (13) rotatably mounted on an axle (E, E'), a rim (11) defining with the hub an annular space (20), and a device (100, 100') for driving the wheel in rotation relative to the axle, the rotational drive device being housed inside the annular space defined by said wheel.

2. Wheel (10) according to claim 1, in which the drive device (100, 100') defines a force transmission chain comprising a bell (125, 113') which has an end for connection to the axle (E) and which is engaged in the annular space (20) so as to also form a cowling of at least a part of the drive device.

3. A wheel according to claim 1 or 2, wherein the drive device (100, 100') comprises an electric motor (110, 110').

4. Wheel (10) according to claim 3, wherein the electric motor (100, 100') is radial flux and comprises a stator (111, 111') and a rotor (112, 112') extending inside said stator.

5. Wheel (10) according to claim 3, wherein the electric motor (100, 100') is radial flux and comprises a stator (111, 111') and a rotor (112, 112') extending around said stator.

6. Wheel (10) according to any one of claims 1 to 5, wherein the drive device (100, 100') comprises a reducer (120, 120') of which an output is rotationally linked to the wheel (10).

7. A wheel (10) according to claim 6, wherein the reducer (120) is a planetary reducer.

8. A wheel (10) according to claim 6 or 7, wherein the reducer (120) is a multi-stage reducer.

9. Landing gear (2) of an aircraft (1) comprising an end comprising an axle (E, E') on which is rotatably mounted a wheel (10) according to any one of the preceding claims.

10. Aircraft (1) comprising at least one landing gear (2) according to claim 9.

Images