EP3827502A1

EP3827502A1 - Rolling device adapted to roll on a ground surface

Info

Publication number: EP3827502A1
Application number: EP19737151.1A
Authority: EP
Inventors: Philippe CACHEUX; Georges Barakat
Original assignee: Universite Le Havre Normandie
Current assignee: Universite Le Havre Normandie
Priority date: 2018-07-24
Filing date: 2019-07-12
Publication date: 2021-06-02
Also published as: US11424650B2; CA3106491A1; KR20210036954A; US20210273508A1; CN112585842A; JP7426030B2; WO2020020673A1; FR3084300B1; JP2021533711A; FR3084300A1

Abstract

A rolling device adapted to roll on a ground surface, comprising at least one motorised wheel (1) comprising a circular stator (2) and a circular rotor (3). The stator (2) comprises a circular slot and a plurality of electromagnetic coils (16) located in the circular slot so that at least two electromagnetic coils (16) are arranged facing one another. The circular rotor (3) comprises a circular strip (45) having side walls and a free end edge connecting the side walls, as well as a contact surface with the ground, said circular strip comprising magnetic elements arranged on the side walls thereof. The circular rotor (3) and the circular stator (2) are assembled by means of assembly means (17) provided on the circular stator (2).

Description

Rolling device suitable for rolling on ground

The invention relates to the field of motorized devices including motorized wheels. The invention also relates to any rolling device and more particularly to wheelchairs equipped with motorized wheels.

More generally, the invention relates to any type of rolling device suitable for riding on a ground, such as a bicycle, a motorcycle, a moped, a scooter, a tricycle, a Segway, a car, an airplane, a robot. , etc.

The concept of a motorized wheel has been known for a long time. The motorized wheel is set in motion by a motor generally located at a distance therefrom. This has a circular shape and is mounted on a hub.

The motorized wheel subsequently underwent changes. The motor originally located outside the wheel was integrated into the wheel.

The motorized wheel can be assembled with different supports in order to make the latter mobile. This is how motorized wheels adaptable to different supports such as bicycles or even wheelchairs, came into being.

Existing motorized wheels include an electric motor. This motor comprises a stator provided with a series of coils and a rotor movable relative to the stator. The rotor is rotated under the effect of a magnetic field induced by the stator coils. This movement allows the wheel to be rotated.

The motorized wheels can support and move a large load. They must therefore generate significant torque at low speed.

Although some motorized wheels develop significant torque, a drawback is that they remain energy-consuming. Their performance is therefore particularly low and the autonomy of the batteries is strongly impacted.

Another drawback lies in the dimensions of the wheel. The motorized wheels intended to develop a high torque are thick so that the motorization can be inserted in its central space. These imposing dimensions disqualify these high power motorized wheels for applications such as bicycles or wheelchairs.

Another disadvantage of motorized wheels is that they are fitted with reducers, which considerably increases their mass, their production cost, decreases their reliability due to the large number of parts that these reducers include, and also increases the noise in use. .

Another drawback of these motorized wheels lies in the magnetic elements used. These magnetic elements are generally permanent magnets made from rare earths. These rare earth magnets have several drawbacks. The extraction and exploitation of rare earths have a negative impact on the environment. In addition, the use of permanent rare earth magnets is problematic since these generate a magnetic force in the absence of an electric current, this due to the remanent induction of these magnets which can reach 1.5 Teslas. . This is inconvenient when you need to manually turn the wheel. Indeed, the rotor then systematically tends to return to a position of magnetic equilibrium. Despite the use of rare earth magnets, this magnetic restoring force can be reduced, but this requires a complex arrangement of the magnetic elements, which significantly complicates the motorized wheels, making them more difficult to produce and increasing their costs. .

Another disadvantage of motorized wheels lies in the fact that their height is fixed. Indeed, the fixing of the wheel to a support such as a wheelchair for example is done substantially in the vicinity of an area located in the center of said motorized wheel. Static mounting of the motorized wheel on its support can be uncomfortable.

The invention aims to remedy at least one of the aforementioned drawbacks for rolling devices. To this end, there is proposed a rolling device adapted to roll on a ground, comprising at least one motorized wheel and a housing (51) for controlling said at least one motorized wheel (1), said at least one motorized wheel comprising: a circular stator comprising a body defining a circular slot and comprising a plurality of electromagnetic coils located in the circular slot so that at least two electromagnetic coils are arranged facing each other, and

- a circular rotor comprising on an inner periphery a circular blade having side walls and a free end edge connecting the side walls (34), the circular rotor comprising a contact surface with the ground, said contact surface extending on an outer periphery, and said circular blade comprising magnetic elements arranged on its side walls, the circular rotor and the circular stator being assembled by means of assembly means provided on the circular stator, the circular blade of the circular rotor being arranged in the circular slot of the circular stator so that the magnetic elements of said circular blade are located between the electromagnetic coils of the circular stator.

Various additional characteristics can be provided alone or in combination:

the body of the circular stator comprises two half-stators fixed to each other so that the circular slot is continuous;

each half-stator has fixing lugs capable of fixing the half-stators to one another, these fixing lugs being located on the inner periphery of said half-stators;

the assembly means, hereinafter called rotary supports, are arranged on the inner periphery of the circular stator;

the rotary supports are arranged on the fixing lugs;

- the rotary supports include:

- an axe,

- two ball bearings mounted on the axle, and

- a roller mounted on the ball bearings; the roller has a groove intended to receive the circular blade of the circular rotor and the groove is in section, at least in part, a counter-impression of the free end edge;

the magnetic elements of the circular rotor comprise an alloy of iron and silicon or ferromagnetic alloy, or permanent magnets without rare earths; the side walls (34) of the circular blade (45) comprising several openings (35) accommodating said magnetic elements (28);

the rolling device comprises adjustment means able to modify the inclination of the axis of the rotary supports so as to adjust a distance separating the circular rotor from the circular stator;

the adjustment means capable of modifying the inclination of the axis of the rotary supports are two eccentric bearings which interface between the axis and the fixing lugs, each eccentric bearing being mounted on either side of the axis;

the device comprises a device for adjusting the position of a point of attachment of said at least one motorized wheel, said adjustment device comprising means for fixing to a connecting axis;

the motorized wheel position adjustment device comprises:

- substantially parallel guide rods fixed to the circular stator,

- an electric motor,

- a worm screw coupled to the electric motor,

a fixing pad comprising the means for fixing to the connecting axis, said fixing pad being mechanically coupled to the worm and to the guide rods so that the rotation of the worm allows the movement of the pad. fixing along the guide rods;

the rolling device includes:

- a microcontroller,

- a power card connected to the microcontroller,

- a battery connected to the power card;

- a battery charger capable of charging the battery, and a computer program is implemented in the microcontroller, said microcontroller being able to successively supply the electromagnetic coils of the circular stator to allow the circular rotor to rotate.

Preferably, the power card can be a power electronics converter.

In particular, a rolling device is proposed, for example a wheelchair, comprising two motorized wheels and a control box for motorized wheels.

Various additional characteristics can be provided alone or in combination:

the control unit comprises a tilt sensor connected to the microcontroller, the tilt sensor being able to measure the attitude of the rolling device and to provide this measurement to the microcontroller so that said microcontroller modifies the position of the wheel attachment point motorized by actuating the electric motor of the motorized wheel height adjustment device.

More generally, the invention relates to any type of rolling device suitable for driving on a ground such as a vehicle intended to transport one or more people, animals or goods or equipment to perform ground services.

In the context of the present invention, the ground is defined as a rolling surface on which the device is intended to roll. For example, it can be a road or street, a path or path, a sidewalk, or a natural ground not covered with a covering.

The invention relates in particular to electrically motorized vehicles such as bicycles, scooters, Segways, compact cars, mopeds, motorcycles, robots. Obviously, the invention is not limited to these few examples given by way of illustration but aims more generally any type of vehicle that can be motorized and intended to move while rolling on the ground.

The invention finds a preferred application in the field of aeronautics, in particular for aircraft landing gear or so more general to any other type of vehicle adapted to move on the ground, in particular by means of thrusters, which cannot back up but can be pulled back.

Other particularities and advantages of the invention will appear in the description below in relation to the appended drawings, given by way of nonlimiting examples and in which:

Figure 1 is a perspective view of a motorized wheel according to the invention; Figure 2 is a perspective view of a stator of the motorized wheel;

Figure 3 is a perspective view of a rotary support of the motorized wheel;

- Figure 4 is an exploded perspective view of the rotary support of Figure 3; Figure 5 is a close-up perspective view of the rotary support of Figures 3 and 4, mounted in the motorized wheel;

Figure 6 is an exploded perspective view of the stator according to the invention;

Figure 7 is a perspective view of the stator according to the invention;

- Figure 8 is another perspective view of the motorized wheel according to the invention;

Figure 9 is a sectional view of the motorized wheel along the plane IX-IX of Figure 1;

Figure 10 is an exploded perspective view of the rotor according to the invention;

- Figure 11 is a perspective view of the rotor of Figure 10;

FIG. 12 is a perspective view of a wheelchair comprising a motorized wheel from the preceding figures;

Figure 13 is a perspective view of a motorized wheel of the previous figures, equipped with a battery and additional electronic elements;

FIG. 14 illustrates an exemplary embodiment of an eccentric bearing;

FIG. 15 shows in perspective the contacting of the rotor with the stator by activation of the eccentric bearings;

FIG. 16 illustrates in perspective and in section a part of the rotor according to a particular embodiment; Figures 17a and 17b illustrate in perspective the rotor and the stator separately and assembled according to a particular embodiment.

In Figure 1 is shown a motorized wheel 1. The motorized wheel 1 comprises a circular stator 2 and a circular rotor 3. The circular stator 2 comprises a body 4. The body 4 is produced by the assembly of two half-stators 5. The half-stators are integral with one another thanks to a plurality of fixing means. Each half-stator 5 has lugs 7 for fixing. The fixing lugs 7 are located on an inner periphery 8 of the half-stators 5 and these are provided with orifice 9 for fixing. On the inside of the fixing lugs 7, the latter comprise an annular fixing housing 10 which is substantially concentric with the fixing orifice 9. The fixing means are in the form of a cylindrical rod 6. The cylindrical rod 6 is arranged between the half-stators 5 and more precisely between fixing lugs 7 located opposite one another. Ends of the fixing rod are housed in the annular housings of the fixing lugs 7.

The cylindrical rod 6 includes an internal threaded orifice 11. On each side of the threaded rod, a screw 12 is inserted through the orifice 9 for fixing inside the internal orifice 11 of the cylindrical rod 6. The half-stators 5 are then secured to one another.

Advantageously, the cylindrical rod 6 has a diameter greater than the fixing holes 9. This allows the threaded rod to fulfill an additional function, in addition to making the two half-stators 5 integral. This additional function consists in keeping the half-stators 5 at a distance from each other. The two half-stators 5 are never in direct contact.

Thus the body 4 defines a circular slot 13. The circular slot 13 is continuous over the entire periphery of the circular stator 2. In other words, the circular slot 13 defines a circular path at 360 ° without any obstacle. This is made possible in particular by the use of two half-stators 5 to obtain the body 4 of the stator 2. Each half-stator 5 has a plurality of teeth 14. The teeth 14 are arranged on an inner face 15 of the half-stators 5 and project therefrom. The teeth 14 have a cubic shape or that of a rectangular parallelepiped. The teeth 14 may have a different shape. Thus, the stator comprises a plurality of pairs of teeth 14 distributed over the periphery of the body 4. Each pair comprises two teeth 14 arranged opposite one another. In other words, in each pair, a tooth 14 of a half-stator 5 faces the other tooth 14 of the other half-stator 5.

The circular stator 2 comprises electromagnetic coils 16. The coils 16 are mounted on the teeth 14. Thus the stator comprises as many coils 16 as there are teeth 14. Just like the teeth 14, the coils 16 of a half-stator 5 are located opposite the coils 16 on the other half-stator 5.

In the embodiment shown in the figures, the circular stator comprises 36 pairs of electromagnetic coils, ie 72 electromagnetic coils.

According to an alternative embodiment, the electromagnetic coils 16 are not distributed over the entire circumference of the half-stators 5 (not shown) but only over one or more parts of the circumference of the stator 2, so as to form one or more several wound segments.

For example, the coils are distributed over half or only a quarter of the circumference of the half-stators, so as to form a so-called "arc" distribution. Such a distribution of the coils advantageously makes it possible to lighten the structure in terms of weight.

According to a particular embodiment, the coils can be distributed so as to form an alternation of active segments known as active arcs and non-exploited segments known as inactive arcs.

According to the embodiment illustrated in FIG. 2, seven pairs of coils 16 are continuously mounted on the two half-stators 5, forming a single segment so that the coils of each pair are opposite one of the other. According to the embodiment illustrated in Figure 7, the two half-stators are assembled in a mirror, so that each tooth 14 of a half-stator 5 is face to face with a tooth 14 of the other half-stator 5.

According to the embodiment illustrated in Figures 2, 6, 7, the two half-stators 5 have the same number of teeth. According to another particular embodiment, the two half-stators 5 have a different number of teeth so that they do not form two twin mirror half-stators. This embodiment of the two half-stators and of the rotor which results therefrom makes it possible to reduce the axial attraction force which the rotor undergoes by the action of the two half-stators and also to reduce potential vibrations of electromagnetic origin.

According to another particular embodiment, the two half-stators 5 are mounted offset from one another, so that the torques exerted by each of the half-stators are in opposition.

According to an alternative embodiment (not illustrated), the two half-stators are assembled in a mirror but the coils 16 can be mounted offset from one another, so that each of the coils of a half-stator is not not face to face with a coil fixed on the other half-stator. This embodiment makes it possible to reduce the toothing torque applied to the rotor due to the variation in the permeance of the air gap. More precisely, this mode makes it possible to oppose the toothing pairs on one and the other of the faces of the rotor and therefore to reduce the total toothing torque.

The stator comprises assembly means below for rotary supports 17, illustrated in FIGS. 3 to 5. The rotary supports 17 are attached and mounted on the fixing lugs 7. To this end, each fixing lug 7 comprises a support hole 18 intended to receive one end 19 of a rotary support 17. The fixing tab 7 has several adjustment orifices 20 formed around the support orifice 18. Each rotary support comprises several elements visible in FIG. 4, namely:

an axis 21 of the support,

- two ball bearings 22 mounted on the axis 21 of the support, a roller 23 mounted on the ball bearings 22,

two eccentric bearings 24 interfacing between the axis 21 of the support and the fixing lugs 7.

An inner ring 25 of the ball bearings is mounted on the axis 21 of the support while an outer ring 26 is mounted on the roller 23. Thus, the roller 23 can be rotated relative to the axis 21 of the support . The roller 23 has a substantially U-shaped guide groove 27. The rotary support is attached and mounted on two fixing lugs 7 located opposite one another as illustrated in FIG. 5 .

An exemplary embodiment of the eccentric bearing 24 is illustrated in FIG. 14.

The bearing is "eccentric" in the sense that it has a housing 240 offset or eccentric relative to the rotation tax of the bearing A24, this housing being intended to receive one end of support tax 21. Thus, the center of said eccentric housing 240 passing through Tax of symmetry of housing A240 does not coincide with the center of bearing 24 passing through Tax of rotation of bearing A24. It follows that the axis of rotation of the roller 23 is offset relative to the axis of rotation of the bearing 24 according to an offset value as represented by the reference "e". For example, the real value of the offset is 5/10 of mm or a travel of +/- 1mm

Ends of the axis 21 of the support are each inserted into an orifice 18 for supporting a fixing tab 7. An eccentric bearing 24 is then attached to the outside of the fixing tab 7 and inserted into the orifice 18 for support. The axis 21 of the support is then inserted into the eccentric bearing 24 which is itself fixed to the fixing lug 7 by means of several screws inserted through the eccentric bearing 24 in the orifices 20 for adjusting the fixing lug 7. The roller 23 rotates freely relative to the eccentric bearings 24. In the embodiment shown in the figures, the motorized wheel 1 comprises three rotary supports 17 arranged at substantially 120 ° from each other.

As previously mentioned, the motorized wheel 1 comprises a circular rotor 3. The circular rotor 3 includes:

a rim 29 extending over an external contour 30, and a circular blade 45 extending over an interior contour 31.

The circular rotor 3 further comprises a tire 32 acting as a contact surface with a ground (not shown in the figures). For example, this tire 32 as illustrated in FIGS. 9, 17a and 17b is intended to roll on a road, a path, a trail or any type of terrain or rolling surface on which the tire can roll.

According to an alternative embodiment (not shown), the tire 32 can be replaced by a set of rollers distributed on the outer periphery of the rotor 3, more particularly on the surface in contact with the ground so as to roll on the ground. For example, the rollers are those of an omnidirectional wheel without tire commonly known as "omni-wheel" or "omni-directional whee!" in English.

Thus, the rotor 3 directly carries the rim 29 and the tire 32 on the rim or any other alternative to the tire adapted to roll on the ground, so that the motorized wheel can be considered as a "wheel motor", that is ie a motor in which the rotor acts as a wheel.

Consequently, it is possible to motorize rolling vehicles by simply replacing all or part of the existing wheels with at least one motorized wheel or "wheel motor" according to the present invention.

The circular blade 45 is fixed to the rim 29 by welding or gluing for example. The circular blade 45 includes a free end edge 33 and side walls 34. The edge 33 of free end is at least in part substantially a counterprint of the groove 27 of the roller 23. The circular blade 45 is a thin plate in the form of a ring. The side walls 34 of the circular blade 45 include several openings 35 intended to receive magnetic elements.

The rotor 3 and the stator are assembled so that the blade of the rotor 3 is arranged in the slot 13. Thus the magnetic elements of the rotor 3 are located between the electromagnetic coils 16 of the stator. In the embodiment shown in the figures, the rotor 3 comprises 24 magnetic elements 28. The edge 33 of the free end of the circular blade 45 is housed in the groove 27 so that the stator is supported on the three rotary supports 17. The groove 27 thus makes it possible to guide the circular blade 45 in rotation, and consequently guide the circular rotor 3 in rotation.

The fact that the groove 27 is at least in part substantially a counterprint of the groove 27 makes it possible to prevent the free end edge 33 from being able to move in the groove 27. The wheel is thus better guided and this allows by elsewhere to avoid derailment of the rotor.

By positioning the fixing lugs 7 on the inner periphery 8 of the half-stators, it is possible to clear a sufficiently large space between the half-stators 5 to allow the most compact possible assembly of the rotor inside said stator. a share and to participate in the reduction of the air gap.

By positioning the rotary supports 17 on an inner periphery, and more precisely on the fixing lugs 7, the assembly of the rotor and the stator is more compact in favor of better mechanical strength.

When the circular rotor 3 is rotated, the circular blade 45 bearing on the rotary supports 17 can rotate without difficulty.

The electromagnetic coils 16 are oriented along the axis X of the wheel. This means that the axis passing through the center of the coils 16 is substantially oriented along the axis X. This makes it possible to reduce the thickness of the wheel unlike a different orientation.

Advantageously, the magnetic elements 28 of the rotor 3 comprise polar masses such as an alloy of iron and silicon.

Preferably, the polar masses comprise a ferromagnetic alloy.

The insertion of polar masses in the rotor 3 is particularly advantageous for making the rotor passive on the electromagnetic plane, in the sense that it contains no electromagnetic source. Indeed, only the electromagnetic coils 16 disposed on the half-stators 5 are supplied by a current source.

Preferably, the polar masses are arranged inside the side walls of the rotor 3, as illustrated in FIG. 16. The circular blade 45 connects the guide ring 33 to the rim 29. For example, the circular blade 45 comprises anchoring means 35, such as slots or notches intended to fix the elements magnetic such as the polar masses 28. Advantageously, these anchoring means are distributed at regular intervals over all or part of the circumference of the circular blade, so as to anchor or fix the polar masses equidistantly.

The side walls of the rotor 3 of the circular blade are made of a non-conductive material, such as fiberglass.

In the example of FIG. 16, the two side walls of the rotor 3 including the polar masses 28 are covered, at least partially with a coating comprising a material with mechanical properties adapted to reinforce or stiffen the rotor 3. For example, this material is carbon fiber, to which is optionally added an epoxy resin. For example, this material is supplied in peripheral zones of the circular blade 45, as designated by the references 3A and 3B in FIG. 16.

Thus, the magnetic elements 28 are devoid of rare earths, which does not hinder the manual movement of the rotor 3 relative to the stator 2.

Note that as a variant, it is still possible to use permanent magnets without rare earths, but this choice does not constitute a preferred embodiment since it involves residual discomfort for manual use.

The air gap is the distance between the rotor 3 and the stator. The adjustment of this distance is carried out using eccentric bearings 24. By moving the eccentric bearings 24 up or down, the axis 21 of the support is inclined, which makes it possible to modify the trajectory of the circular blade 45 thanks to the action of the groove 27 of the roller 23 on the edge 33 free end. The air gap can thus be adjusted in order to increase the performance of the motorized wheel 1, in particular in order to improve its torque when stationary and therefore move a large load despite its small thickness along the X axis.

FIG. 15 illustrates in perspective the positioning of the free end 33 of the rotor 3 (ie rolling rod) relative to the groove 27 of the roller 23 of a rotary support 17 between the two half-stators 5. The position of the bearings eccentrics 24, when engaged in the openings 18 of the half-stators 5, can be adjusted by rotation. AT For this purpose, a slot 242 is provided on the outer surface of the bearings 24 to rotate the eccentric bearing.

Thus, the simultaneous rotation of the two bearings 24 on each half-stator 5 makes it possible to move the guide roller 23 closer or further away from the rolling rod 33 of the rotor 3, by virtue of the eccentric housings 240 provided on each of the eccentric bearings 24 The position of the support 21 connecting the two bearings 24 is adjusted by rotation of the bearings 24.

In the "remote" position as shown in FIG. 15a, the rotor 3 is not in contact with the stator 2. The eccentric bearings 24 are in a so-called remote position. For example, this position is materialized by an oblique orientation of the slot 242.

In the "in contact" position as shown in FIG. 15b, the rotor 3 is in contact with the stator 2. This position is obtained by rotation of the eccentric bearings 24 around their axis of rotation A24, as defined in the figure 14. For example, this position called "in contact" is materialized by a horizontal orientation of the slot 242. Due to the eccentricity of the housings 240, the rotation of the bearings 24 has the effect of displacing the axis 21 so that the free end 33 of the guide ring comes into contact with the slot in the roller 23.

Thus, the rotation of the eccentric bearings 24 makes it possible to adjust the operating clearances of the rotor 3 radially and axially.

Figure 17a illustrates the rotor 3 and the stator 5 shown side by side. The rotor 3 comprising the circular blade 45 and the polar masses 28 distributed at regular intervals on the circular blade 45 by anchoring in openings 35 as described above. For reasons of clarity of representation, the polar masses 28 appear free, that is to say not covered on either side of the blade 45.

The stator 2 has a slot defined between the teeth around which the coils are wound 16. In this embodiment, the coils 16 are wound around the teeth in such a way that they do not protrude an extreme part of the teeth extending towards the center of the slot. Thus, a continuous slit of width equal to the distance between the top of two teeth facing each other is formed.

FIG. 17b illustrates an assembly of the rotor 3 and the stator 2 of FIG. 17a, more precisely in the case where the guide ring 33 of the rotor 3 is in contact with the bearing 23 of the stator 2.

The motorized wheel thus comprises a central zone which can be used to house various operating and control elements of the motorized wheel 1.

The motorized wheel 1 includes:

a microcontroller 46,

a power electronics, for example a power card 47 connected to the microcontroller 46,

a battery 48 connected to the power card 47, and

a battery charger (not shown) connected to the power card 47. Preferably, said card is a power electronics converter 47 adapted to supply the motor and control the battery charger. These two functions can be implemented within the same electronic card.

The motorized wheel 1 further comprises an inverter, for example of 48 V and 500 W for generating alternating voltages and currents.

The microcontroller is connected to a control unit 51 making it possible to give information such as the direction of movement, the speed of rotation as a function of the wish expressed by a user. The control unit 51 can be connected to the microcontroller using appropriate wiring or wirelessly, in the latter case, the microcontroller is equipped with data transmission / reception means.

The operating principle of the motorized wheel 1 will now be described.

Depending on the wish expressed by the user, the microcontroller manages the supply of the electromagnetic coils 16.

The motorized wheel 1 is set in motion by supplying the electromagnetic coils 16 with an electric current coming from the battery. The microcontroller supplies the electromagnetic coils 16 (in pairs) in turn. This alternation causes a rotation of the magnetic field and thus causes a movement of the rotor 3 advancing the motorized wheel 1.

In the following, an example of application of the motorized wheel will be described. For example, two motorized wheels are mounted on a connecting axis of the wheelchair. The table below summarizes the operation of the motorized wheels according to the wish expressed by a user on a control box 51 connected to the motorized wheels:

In general, the control unit comprises a man / machine interface intended to send control signals to the motorized wheel to allow the user to control the rolling device on which the motorized wheel 1 is mounted. By way of example Illustrative, the control unit 51 includes a steering wheel and / or a joystick. It can be connected to one or more sensors, such as gyroscopes, accelerometers, intended to provide information relating to the environment in which the rolling device moves.

Advantageously, the motorized wheel 1 comprises a device 37 for adjusting the position of the wheel, as illustrated in FIGS. 1 and 8. More specifically, the device 37 makes it possible to adjust in real time the position of a fixing or anchoring point 42 of the motorized wheel 1 on the rolling device, so as to maintain optimal ground clearance of the rolling device according to the configuration of the ground (eg degree of inclination or slope of the rolling surface). Thus, the stability of the rolling device is ensured by improved ground handling, at all times, especially when the device is rolling on the ground.

The adjustment device 37 comprises a rail 38 provided with two guide rods 39 fixed on the stator. The guide rods 39 are oriented along a diameter of the stator and positioned on either side of this diameter. The guide rods 39 are substantially parallel. The device comprises an electric motor 40 mechanically coupled to a worm 41. The endless screw 41 is arranged between the guide rods 39. The device further comprises a fixing pad 42. The fixing pad 42 includes an interface for mechanical coupling to a connecting pin.

The use of a connecting pin advantageously makes it possible to free up space inside the wheel to install, for example, a battery and one or more electronic cards, an inductive battery charger for contactless charging, such as described with reference to Figure 13.

The shoe 42 also comprises orifices 43 for guiding intended to receive the rods 39 for guiding and orifices 44 tapped for receiving the screw 41 without threaded end. When the endless screw 41 is rotated, the shoe moves along the guide rods. A suitable endless screw 41 is for example a ball screw.

Advantageously, the housing 51 comprises a tilt sensor connected to the microcontroller. The inclination sensor makes it possible to determine the attitude of the wheelchair 50 and thus give the necessary information to the microcontroller, such as a measurement of the attitude or degree of inclination of the wheelchair, so that it can act on the position of the fixing pad 42 along the endless screw 41, in the motorized wheel 1, in order to ensure the user seated on the wheelchair a horizontal position in all circumstances. For example, when the wheelchair engages on an inclined, sloping road, the microcontroller starts the motor 40 electric in order to reassemble the fixing pads and keep the seat of the wheelchair in a horizontal position.

The motorized wheels are advantageously equipped with an obstacle detector, a distance detector and a GPS chip. These elements connected to the microcontroller allow the motorized wheels to reach a battery recharging station independently in a confined space such as an apartment.

The motorized wheel described above has many advantages, namely: it develops a large torque at low speed without being energy-consuming, in particular thanks to the arrangement of the circular blade 45 in the circular slot,

it has a small thickness, suitable for use on a wheelchair or even a bicycle,

it does not require the use of reducers, which considerably reduces its mass, its production cost and improves its reliability while reducing noise in use,

no permanent rare earth magnet is used, which allows the wheel to be turned manually without difficulty, which is perfectly suitable for a wheelchair or even a bicycle for example.

The present invention has been described in detail in the context of a wheelchair but is obviously not limited to this application. It relates more generally to a device intended to roll on a ground and comprising at least one motorized wheel as described above.

In particular, the rolling device can be any type of motorized vehicle such as a bicycle or an electric bicycle, an electric scooter, a Segway, a compact electric car, a moped or an electric motorcycle, a robot. This list is given for illustrative purposes and should in no way be interpreted in a restrictive manner.

Claims

1. Rolling device adapted to roll on a ground, said device comprising at least one motorized wheel (1) and a housing (51) for controlling said at least one motorized wheel (1), said at least one motorized wheel comprising:

a circular stator (2) comprising a body (4) defining a circular slot (13) and comprising a plurality of electromagnetic coils (16) located in the circular slot (13), so that at least two electromagnetic coils (16) are arranged opposite one another, and

- a circular rotor (3) comprising on an inner periphery (8) a circular blade (45) having side walls (34) and a free end edge (33) connecting the side walls (34), the rotor (3 ) circular comprising a contact surface with the ground, said contact surface extending over an external periphery, and said circular blade (45) comprising magnetic elements (28) arranged on its side walls (34),

the circular rotor (3) and the circular stator (2) being assembled by means of assembly means (17) provided on the circular stator (2), the circular blade (45) of the circular rotor (3) being arranged in the circular slot (13) of the circular stator (2) so that the magnetic elements (28) of said circular blade (45) are located between the electromagnetic coils (16) of the circular stator (2).

2. Rolling device according to claim 1, characterized in that the body (4) of the circular stator (2) comprises two half-stators (5) fixed to one another so that the circular slot (13) is keep on going.

3. Rolling device according to claim 2, characterized in that each half-stator (5) has lugs (7) for fixing capable of fixing the half-stators (5) to one another, these lugs (7 ) of fixing being located on the inner periphery (8) of said half-stators (5).

4. Rolling device according to claim 3, characterized in that the means (17) of assembly called rotary supports (17), are arranged on the inner periphery (8) of the stator (2) circular.

5. Rolling device according to claim 4, characterized in that the rotary supports (17) are arranged on the fixing lugs (7).

6. Rolling device according to claim 4 or 5, characterized in that the rotary supports (17) comprise:

- an axis (21),

- two ball bearings (22) mounted on the axis (21), and

- a roller (23) mounted on the ball bearings (22). 7. Rolling device according to claim 6, characterized in that the roller (23) has a groove (27) intended to receive the circular blade (13) of the rotor (3) circular and in that the groove (27) is in section, at least in part, a counter-impression of the free end edge (33). 8. Rolling device according to one of the preceding claims, characterized in that the magnetic elements (28) of the circular rotor (3) comprise an alloy of iron and silicon or a ferromagnetic alloy.

9. Rolling device according to one of claims 1 to 7, characterized in that the magnetic elements (28) of the circular rotor (3) comprise permanent magnets without rare earths.

10. Rolling device according to claim 8, characterized in that the side walls (34) of the circular blade (45) comprise one or more openings (35) receiving said magnetic elements (28).

11. Rolling device according to one of claims 6 to 10, characterized in that it comprises means (24) for adjustment capable of modifying the inclination of the axis (21) of the supports (17) which rotate so as to set a distance separating the circular rotor (3) from the circular stator (2).

12. Rolling device according to the preceding claim, characterized in that the adjustment means (24) able to modify the inclination of the axis (21) of the rotary supports (17) are two eccentric bearings (24) interfacing between the 'axis (21) and the lugs (7) for fixing, each eccentric bearing (24) being mounted on either side of the axis (21).

13. Rolling device according to one of the preceding claims, characterized in that it comprises a device (37) for adjusting the position of a fixing point (42) of said at least one wheel (1) motorized to said device rolling, said adjusting device (37) comprising means for fixing to a connecting pin.

14. Rolling device according to the preceding claim, characterized in that the device (37) for adjusting the position of the fixing point (42) of said at least one motorized wheel (1) comprises:

- substantially parallel guide rods (39) fixed to the circular stator (2),

- an electric motor (40),

- an endless screw (41) coupled to the electric motor (40),

- A fixing pad (42) comprising the means for fixing to the connecting pin, said fixing pad (42) being mechanically coupled to the endless screw (41) and to the guide rods (39) so that the rotation of the endless screw (41) allows the displacement of the fixing shoe (42) along the guide rods (39).

15. Rolling device according to one of the preceding claims, characterized in that it comprises:

a microcontroller (46),

a power card (47) connected to the microcontroller (46), - a battery (48) connected to the power card (47),

a battery charger capable of charging the battery (48), and in that a computer program is implemented in the microcontroller (46), said microcontroller (46) being capable of successively supplying the electromagnetic coils (16) of the stator (2) ) circular to allow the rotation of the circular rotor (3).

16. Rolling device according to any one of the preceding claims, characterized in that the rotor (3) further comprises a tire (32) or a set of rollers distributed on the outer periphery of the rotor (3) acting as a surface for contact with the ground.

17. Rolling device according to any one of the preceding claims, characterized in that the control box (51) comprises a tilt sensor connected to the microcontroller, the tilt sensor being able to measure the attitude of the device (50 ) rolling and providing this measurement to the microcontroller

(46) so that said microcontroller (46) modifies the position of the attachment point of said at least one motorized wheel (1) by actuating the electric motor (40) of the device (37) for adjusting the position of the attachment point of said at least one motorized wheel (1).

18. Rolling device according to any one of the preceding claims, characterized in that the rotor (3) comprises a rim (29) extending over an external contour (30) and in that the circular blade (45) connects the edge free end (33) to said rim (29).

19. Rolling device according to any one of the preceding claims, characterized in that the walls of the blade (45) are reinforced at least at its ends (3A, 3B) by a coating of carbon fiber comprising a resin of epoxy type.