ELECTRIC DRIVE DEVICE FOR MOTORING VEHICLES

Abstract

The invention relates to a contactless drive device for a wheel of a rolling vehicle, comprising: a primary unit (3) fixed to the vehicle and having at least one magnetic pole, and a secondary unit (2) fixed to the wheel and having at least one part made of a material: having an electrical conductivity greater than 10⁵ Siemens / meter and preferably greater than 10⁶ Siemens / meter, and a relative magnetic permeability less than 100 and preferably less than 10, wherein the primary and secondary units face each other at least temporarily during one wheel rotation. Figure to be published with the abstract: Fig. 14

Description

Title of the invention: ELECTRIC DRIVE DEVICE FOR MOTOR VEHICLES FIELD OF INVENTION

[0001] The present invention relates to the general technical field of electric drive or electric assistance devices for rolling vehicles.

[0002] In the context of the present invention, "electric assistance" means the implementation of an electromagnetic conversion for the purpose of driving (or assisting in driving) at least one wheel of the rolling vehicle.

[0003] For the purposes of the present invention, the term "rolling vehicle" means a mobile system including at least one wheel, the mobile system being usable: • for mobility purposes, for example, but not limited to, for personal mobility purposes such as, for example, but not limited to, bicycles, scooters, skateboards and wheelchairs, or used • for the purpose of transporting goods or people such as, for example but not limited to, robots and trailers.

[0004] In particular, the present application relates to the technical subfield of electric drive devices - or electric assistance devices - for bicycles, in which the electric drive device complements (or replaces) the torque applied by the cyclist on the crankset.

[0005] Such electric drive devices become usable when the additional torque referred to one of the wheels is, for example but not limited to, greater than or equal to 1 Nm.

[0006] The term "bicycle" refers to all existing types without limitation, in particular cycles and especially: • road or racing bicycles, • Dutch bicycles, all-road, fixie, all-terrain, or cargo bikes, but also • recumbent or folding bicycles, • tandem bicycles, • three-wheeled and four-wheeled cargo bikes, etc.

[0007] BACKGROUND OF THE INVENTION

[0008] An electric assistance device typically comprises: • at least one single-unit electric motor consisting of a stator, a rotor and at least one system for guiding the rotation of the rotor relative to the stator (for example a ball bearing), • optionally, means of multiplication or reduction (for example, an epicyclic converter), • coupling means between the motor rotor (or the output of the mechanical converter) and a moving element mechanically linked to a wheel (for example the crankset, a chainring, a sprocket, the chain, a tire or a rim), • optionally a freewheeling mechanism, • optionally, measuring devices (e.g., sensors), • electronic conditioning and control means, and • means of supplying electrical energy.

[0009] The electric motor is, for example, a permanent magnet synchronous machine for good performance in terms of power density and conversion efficiency. A typical example of measuring means is a pedal sensor detecting the rotation of the crankset, or a sensor measuring the torque applied by the cyclist to the crankset. A battery or supercapacitors can, for example, be used for energy storage.

[0010] Examples of electric assistance devices implementing a coupling system directly on the wheel hub (front wheel or rear wheel) have been described in patent EP3131185A1.

[0011] Examples of electric assistance devices implementing a gear coupling system at the level of the pedal assembly have been described in patent EP3036151A1.

[0012] Examples of electric assistance devices implementing a chain-level coupling system have been described in patent EP4010241A1.

[0013] Examples of electric assistance devices implementing a friction coupling system on the tire (front wheel or rear wheel) have been described in patents EP3947130A1 or EP2928764A1.

[0014] Examples of electric assistance devices implementing a coupling system at the level of the rear disc brake have been described in patent EP4200150A1.

[0015] However, known electric assistance devices have various disadvantages.

[0016] In particular, known devices are relatively complex from a mechanical point of view, due to the large number of mechanical parts they incorporate, which poses a problem in terms of wear, maintenance, volume and mass.

[0017] Moreover, known devices are generally oversized in terms of power and autonomy compared to everyday use such as urban commuting to and from the office, which poses an ecological problem.

[0018] Moreover, known devices are generally heavy and bulky, which poses a problem of convenience, for example in comparison with a non-electrically assisted muscle bicycle.

[0019] Also, the majority of known devices are fitted to new vehicles and are not suitable for the refurbishment (or "retrofitting") of existing vehicles. In the rare cases where such known devices are available as retrofit kits, they are not entirely satisfactory because: • they are complex to install, and / or because • the coupling is not efficient, and / or because • Their installation is permanent or near-permanent, which poses a problem: • if the need for assistance is only occasional, or • if one wishes to equip separate vehicles alternately, or • if you wish to remove all or part of the assistance system from the vehicle by example to prevent its theft or vandalism by a third party.

[0020] Finally, known devices may have other drawbacks, including: • from an ecological point of view, since these known devices can use rare earth elements, • in terms of cost, since these known devices are relatively expensive, which poses a problem for widespread adoption, particularly for equipping an existing bicycle, • in terms of autonomy, since these known devices generally do not allow energy to be recovered during braking phases of the moving vehicle.

[0021] One object of the present invention is to provide a training device that makes it possible to overcome at least one of the aforementioned drawbacks.

[0022] BRIEF DESCRIPTION OF THE INVENTION

[0023] To this end, the invention proposes an electric assistance device for a vehicle comprising at least one wheel, configured to be powered by electrical energy supply means in order to allow the rotation of said and at least one wheel, notable in that the electric assistance device comprises: • a primary unit suitable for being fixed to a vehicle frame – such as a steering component, for example a fork, or such as a chassis, for example a frame, the primary unit including at least one primary magnetic pole, said and at least one primary magnetic pole being adapted to generate a magnetic field from electrical energy supplied by the electrical power supply means, • a secondary unit capable of being: • fixed to said and at least one wheel, or • integrated into said and at least one wheel, the secondary unit including at least one induction part, said and at least one induction part being made of a material: • with an electrical conductivity greater than 10⁶ Siemens / meter and preferably greater than 10⁷ Siemens / meter, and • of relative magnetic permeability less than or equal to 10 and preferably less than or equal to 2, the primary and secondary units being configured to face each other at least temporarily over one wheel revolution, the primary and secondary units extending opposite each other through an air gap of average thickness between 0.5 millimeter and 10 millimeters when they face each other, so that when the wheel moves in rotation, the magnetic field generated by said and at least one primary magnetic pole induces a mechanical torque in a direction of rotation of the wheel at least temporarily over one wheel revolution.

[0024] The reader will appreciate that the primary and secondary units are guided in rotation relative to each other by the means existing on the vehicle, and that no other guiding means than those inherent to the vehicle are necessary. In other words, the device does not require means for guiding the primary and secondary units in rotation relative to each other, as the existing means inherent to the vehicle provide such guidance.

[0025] Preferred but not limiting aspects of the device according to the invention are as follows: • the vehicle may be a bicycle, a cheek of a rim of said bicycle and at least one wheel forming said bicycle and at least one induction part; • said and at least one cheek (forming said and at least one induction piece) may have a thickness greater than 2 millimeters on at least one orthoradial portion of the rim; • said and at least one cheek may have a radial width greater than 15 millimeters on at least one orthoradial portion of the rim; • the vehicle may be a bicycle, a disc brake of said and at least one wheel forming said and at least one induction part; • The vehicle may be a bicycle, the device comprising: • a single induction element, said single induction element being a plate of generally annular shape with an angular opening of less than or equal to 360°, or • a plurality of induction pieces, each induction piece consisting of a plate of any shape arranged in relation to at least one other induction piece of the plurality in an assembly of overall annular shape with an angular opening less than or equal to 360°; the single part - or plurality of parts - being fixed on a component of said and at least one wheel chosen from a rim, a spoke, a hub of said and at least one wheel; • the vehicle may be a bicycle, said and at least one induction part being integrated into a tire of said and at least one wheel; • the secondary unit may also include at least one additional ferromagnetic part, associated with said and at least one induction part, the distance separating said and at least one additional part and said and at least one induction part being less than three times the average thickness of the air gap, said and at least one additional part preferably being in contact with said and at least one induction part; • The primary unit may also include: • a case including: • a front panel designed to face the secondary unit, • a rear wall opposite the front wall, and • at least one side wall between the front and rear walls, said walls being made of an electrically insulating material, • the means of supplying electrical energy, • at least one electronic module electrically connected to the electrical power supply means, said and at least one electronic module including an electrical power converter to convert a direct current from the electrical power supply means into an alternating current, said and at least one primary magnetic pole, said means of supplying electrical energy, and said and at least one electronic module being housed in the casing; • The vehicle can be a bicycle, with the primary unit fixed to the frame: • at the level of at least one of the caliper mounting points of the said bicycle, or • at the level of at least one of the disc brake caliper mounting points of said bicycle, said and at least fixing being integrated into the fork or in the rear axle; • the vehicle may be a bicycle, at least a part of the primary unit having a degree of rotational freedom, approximately along an axis A-A' of wheel movement (in particular tangential to the wheel movement), relative to the frame, and at least a portion of the face of the secondary unit intended to come into contact with the primary unit at least temporarily on one wheel rotation, being made of a rubber material or a rubber mixture; • the primary unit may include at least two magnetic poles, and in which the supply of said magnetic poles is controlled according to a scalar control of the family of "V / f" control.

[0026] The invention also relates to a vehicle comprising at least one wheel extending in a plane, notable in that the vehicle comprises at least one electric assistance device as described above.

[0027] According to the invention, when the primary unit has several magnetic poles, these can be assembled according to a three-phase combination (respectively according to a two-phase combination).

[0028] Advantageously, each magnetic pole of the primary unit can be constituted by winding an insulated cable around branches of a ferromagnetic core.

[0029] In addition, the primary unit may include means for "static" adjustment of the position of the primary unit relative to the secondary unit, implemented during the mounting of the primary unit on the vehicle in order to configure the air gap in a particular and, for example, nominal arrangement.

[0030] Also the primary unit may include means for "dynamic" adjustment of the position of the primary unit relative to the secondary unit, implemented during the movement of the vehicle in order to limit variations in air gap.

[0031] Furthermore, the movement and / or tension on at least one brake cable of the vehicle can be used as a control command at the level of the control means, for example to brake the vehicle at least partially by induction.

[0032] Furthermore, the variation in hydraulic pressure in at least one of the braking circuits of said vehicle can be used as a control instruction at the level of the control means, for example to brake the vehicle at least partially by induction.

[0033] Advantageously the primary unit can be designed to be dismountable, at least partially.

[0034] The invention also relates to a method of electrifying a muscle bicycle by means of a "turnkey" kit comprising the device described above, the method comprising: • if an element of the wheel of the muscle bicycle forms the induction part of the secondary unit (for example the rim, or the brake disc, etc.): • the fixing of the primary unit in an area of ​​the fork or frame of said bicycle, said area being chosen so that the primary unit passes opposite the induction part at least temporarily during one wheel rotation, • if the "turnkey" kit includes a modified wheel (for example, a wheel in which an induction component has been integrated by the manufacturer into one of the wheel's elements (tire, rim, brake disc, etc.): • replacing one of the bicycle wheel(s) with the modified wheel supplied in the "turnkey" kit, • the fixing of the primary unit in an area (of the fork or frame) chosen so that the primary unit passes opposite the induction part at least temporarily during one wheel rotation, • if the "turnkey" kit includes an induction part to be fixed to a component (for example on one (or more) spoke(s) of the wheel: • the fixing of the induction part onto a wheel element, and • the fixing of the primary unit in an area (of the fork or the frame) chosen so that the primary unit passes opposite the induction part at least temporarily on one wheel rotation. Brief description of the drawings

[0035] Other advantages and characteristics of the drive device will become apparent from the following description of several embodiments, given by way of non-limiting examples, based on the accompanying drawings in which: • [Fig.IA] is a schematic cross-sectional representation of a primary unit of a drive device according to the invention, said primary unit extending opposite a rim of a bicycle wheel; • [Fig. IB] is a partial schematic front view representation of the primary unit illustrated in [Fig.1A]; • [Fig. IC] is a schematic side view representation of an example of positioning of the primary unit illustrated in [Fig. lA]; • [Fig.2] is a schematic cross-sectional representation of two units primary units of one (or more) drive devices, said primary units extending opposite a rim of a bicycle wheel; • [Fig.3A] and [Fig.3B] are schematic cross-sectional representations of different variants of secondary units of the drive device, said secondary units being made up of modified bicycle wheel rims; [Fig.4A], [Fig.4B] and [Fig.4C] are schematic side view representations of other variants of secondary units, said secondary units being distinct from the rim of the bicycle wheel; [Fig. 5A] and [Fig. 5B] are schematic cross-sectional representations of other examples of drive devices in which: • The primary unit extends along the side of a bicycle wheel tire, • the secondary unit is integrated into the bicycle wheel tire, either at the level of a sidewall of the tire, or at the level of a tread of the tire; [Fig.6] is a partial schematic front view representation of an example of electrical conductors of the primary unit; [Fig.7] is a partial schematic front view representation of another example of electrical conductors; [Fig.8] is a schematic cross-sectional representation of a variant embodiment of the primary unit; [Fig.9] is a schematic side view representation of other variants of primary units arranged opposite the front and rear wheels of the bicycle; [Fig.1OA] and [Fig.1OB] are schematic front view representations of a rear triangle of the bicycle, said rear triangle being equipped ([Fig.1OB]) or not equipped ([Fig.1OA]) with the primary unit of the drive device; [Fig.lOC] and [Fig.lOD] are schematic front view representations of a front fork of the bicycle, said front fork being equipped ([Fig.lOD]) or not equipped ([Fig.lOC]) with the primary unit; [Fig.llA], [Fig.llB], [Fig.llC], [Fig.llD] are schematic perspective representations of primary units having different shapes; [Fig.l2A], [Fig.l2B], [Fig.l2C], [Fig.l2D] and [Fig.l2E] are schematic side view representations of different examples of positioning the primary unit on a rear axle of the bicycle; [Fig.13A], [Fig.13B] and [Fig.13C] are schematic side-view representations of different examples of primary unit positioning on a bicycle front axle, [Fig. 14] is a schematic diagram of the drive device, [Fig. 15] is a schematic diagram of the primary unit. DETAILED DESCRIPTION OF THE INVENTION

[0036] 1. Remarks

[0037] We will now describe different examples of electric drive devices for rolling vehicles with reference to the figures.

[0038] For the sake of clarity, the same elements have been designated by the same references in the different figures and, moreover, the various figures are not drawn to scale.

[0039] Furthermore, in the rest of the description, unless otherwise indicated, the terms "approximately", "substantially", "about", "in the order of", "almost", etc., mean "within 20% and preferably within 5%", or "within 10° and preferably within 5°" when they refer to angular distances, and directional references such as "vertical", "horizontal", "lateral", "below", "above", "superior", "inferior", etc., apply to devices oriented in the manner illustrated in the corresponding views, it being understood that, in practice, these devices may be oriented differently.

[0040] 2. Development of the problem

[0041] We are particularly interested here in electric drive devices for rolling vehicles, and more specifically in rotating drive devices, for example drive devices whose stator or rotor electromagnetic elements have a general ring shape or are distributed according to a general ring shape, or, more generally, drive devices whose stator or rotor electromagnetic elements have a circular annular band shape with an angular opening of less than or equal to 360° or are distributed according to a circular annular band shape with an angular opening of less than or equal to 360°.It will be understood from the following that all the embodiments, modes of embodiment, and variant embodiments described in this application can be adapted to other types of electromagnetic drive devices, for example, linear drive devices. The adaptation of the examples and modes of embodiment described in this application to other types of electromagnetic drive devices is within the scope of those skilled in the art and will therefore not be detailed below.

[0042] Apart from the specific case of motors integrated into the wheel hub, state-of-the-art electric assistance devices for vehicles have in common a power transmission chain composed of at least two distinct elements: a monobloc electric motor, that is to say, one integrating a stator and a rotor, • a mechanical coupling between the rotor of said motor and a moving element in mechanical connection with a wheel (for example the crankset, a chainring, a sprocket, the chain, a tire or a rim).

[0043] Said mechanical coupling is ensured by a contact connection, either a gear connection as described in patents EP3036151A1, EP4010241A1 and EP4200150A1, or a friction connection as described in patents EP3947130A1 and EP2928764A1.

[0044] The existence of at least one such contact in the transmission chain presents several major disadvantages, which can pose a problem in certain applications, in particular applications in which all or part of the drive device was not installed at the time of construction of the bicycle (retrofit applications), or applications in which it is desired to temporarily disconnect at least part of the transmission chain.

[0045] It would be desirable to have drive devices for rolling vehicles, and in particular drive devices for bicycles, whose power transmission chain has at least one coupling without mechanical contact.

[0046] Thus, according to the invention, the aim is to transmit power through air between a fixed reference frame and a rotating reference frame within a drive device for a moving vehicle. To this end, the inventor proposes a particular drive device, which will be described below.

[0047] 3. System Description

[0048] The electric drive device according to the invention is specially adapted for driving a rolling vehicle including one (or more) wheel(s).

[0049] In the following, the various components of the drive device will most often be described with reference to a bicycle, it being understood by those skilled in the art that this drive device can be used with other types of rolling vehicles.

[0050] Figure 14 is a schematic diagram of the drive device according to the invention in which: • A frame 10 represents a fixed reference point of the vehicle, for example the fork or the frame of said vehicle, • a wheel 11 represents a moving reference frame, for example the rim, the spokes or the tire of said wheel.

[0051] In the example of [Fig. 14], the drive device comprises: • a primary unit 3 mounted on the armature 10, and intended to emit a magnetic field 12, • a secondary unit 2 mounted on the wheel 11, and intended to receive, at least temporarily over one wheel rotation, the magnetic field 12 emitted from the primary unit 3, field 12 being approximately oriented so as to promote coupling between primary unit 3 and secondary unit 2, and more specifically so as to promote the establishment of induction phenomena in secondary unit 2 in the presence and near primary unit 3.

[0052] As will be described in more detail later, the magnetic field emitted from the primary unit 3 and received by the secondary unit 2 makes it possible to apply a force tangential to the direction of movement of the bicycle wheel. This tangential force can, for example, be added to the driving force applied by the user via the pedals, thus facilitating the movement of the bicycle.

[0053] The primary unit 3 and secondary unit 2 are electrically isolated from each other, separated by an air gap 13 (for example, a layer of air), but intended to be magnetically coupled together. To achieve this, the primary unit 3 and secondary unit 2 are configured so that they are positioned close to each other, at least temporarily over one wheel rotation.

[0054] In particular, the average distance separating the primary unit 3 and secondary unit 2, i.e. the average thickness of the air gap 13, can be between 0.5 millimeters and 10 millimeters, and preferably between 0.5 millimeters and 5 millimeters.

[0055] In order to function, the drive device also includes or uses: • means of supplying electrical energy 4, and • means for converting electrical energy 5, for example capable of converting direct electrical energy into alternating energy, and possibly vice versa for energy recovery operation, • measuring means 6 and / or conditioning means 7, • control systems 8, • optionally human-machine interface means 9.

[0056] In the following, we will speak interchangeably of "modules" or "means" to refer to means 4, 5, 6, 7, 8 and 9.

[0057] 3.1. Primary Unit

[0058] Figure 15 is a schematic diagram of the primary unit 3, in which: • an axis A-A' represents the tangent to the displacement of the secondary unit in front of the primary unit. • an N-N' axis orients the surface of the primary unit which faces the secondary unit at least temporarily over one wheel rotation.

[0059] In the following, the A-A' axis is called the "propagation axis" and the N-N' axis is called the "normal axis".

[0060] The normal axis N-N' is directed approximately orthogonally with respect to the propagation axis A-A', and also approximately orients said surface of the secondary unit which faces the primary unit.

[0061] In the example of [Fig. 15], the primary unit 3 comprises: • a 25mm casing represented by a box and in which are housed • one (or more) primary magnetic pole(s) 30, represented by a coil, and • the primary electronic module for electrical energy conversion 5 electrically connected to the primary magnetic pole(s) 30 via connection means such as cables, the primary electronic module 5 including, for example, a primary electronic converter (such as a switching inverter) for converting direct current into alternating current, and • the means of supplying electrical energy 4, the means of measurement 6 and / or conditioning 7, the means of control 8, and the means of human-machine interface 9 (if they exist), the whole of said modules 4, 6, 7, 8, 9 being called "auxiliary modules" in the following.

[0062] The primary magnetic pole(s) 30 of the primary unit 3 uses the electrical energy supplied by the electrical energy supply means 4, converted by the primary electronic electrical energy conversion module 5, to generate the magnetic field 12.

[0063] Figure 15 is a special case of a drive device in which the housing 25 of the primary unit 3 incorporates all the modules (except for certain sensors, for example a pedal sensor or a torque sensor located at the bottom bracket), and in particular is not limited to the primary magnetic pole(s) 30. This special case, although advantageous particularly for retrofit applications, is not exclusive of other embodiments in which certain modules are located outside the housing 25, for example: • embodiments in which the means of supplying electrical energy are an external battery fitted to the vehicle and whose terminals are accessible, or • embodiments in which the human-machine interface means are located close to the vehicle control interface, for example the handlebars on a bicycle.

[0064] 3.1.1. Housing

[0065] The housing 25 is intended to protect the primary magnetic pole(s) 30 and the electronic module 5, and / or the auxiliary modules 4, 6, 7, 8, 9. The housing 25 also allows the primary magnetic pole(s) 30 to be electrically isolated from the outside and in particular from the secondary unit 2.

[0066] The 25-unit case includes: • a front wall 20 constituting an interface surface opposite which the secondary unit 2 is intended to be positioned, at least temporarily, on a wheel rotation, • a rear wall 22, opposite the front wall 20, preferably but not necessarily parallel, and • at least one side wall 21 between the front wall 20 and rear wall 22.

[0067] The front wall 20 of the housing 25 is made of an insulating (and non-magnetic or weakly magnetic) material, in order to be permeable to the magnetic field emitted from the primary unit 3. The walls 21 and 22 of the housing 25 are preferably made of an electrically insulating material.

[0068] The outer face of the front panel 20 may optionally include positioning or decorative markers, such as a drawing or a label. These positioning markers allow, in particular, the front face 20 to be distinguished from the rear face 22 of the housing 25.

[0069] The housing 25 also includes fastening means for attaching the primary unit 3 to the frame 10, for example to the fork or the frame in the case of a bicycle. These fastening means can be of any type known to those skilled in the art.

[0070] The housing 25 can have different shapes depending on the desired aesthetic or the intended application. In particular, the housing 25 can be rectangular and extend along a longitudinal axis. Alternatively, the housing can have a curved shape, such as a portion of a ring, and extend along a curved axis.

[0071] The housing 25 extends preferentially along the propagation axis A-A'.

[0072] As will be described in more detail later, the rear walls 22 and / or side walls 21 of the housing 25 may, for example, include the human-machine interface means 9 (if they exist).

[0073] 3.1.2. Magnetic pole(s)

[0074] As previously stated, the primary unit 3 comprises at least one primary magnetic pole 30 contained in the housing 25, positioned so as to generate the magnetic field 12 oriented in such a way as to promote coupling between the primary unit 3 and the secondary unit 2, that is to say preferably: • oriented along the normal N-N' axis, and • positioned close to the front wall 20 of the housing 25.

[0075] The magnetic pole(s) 30 can be made from: • of one (or more) winding(s) of turns whose average plane is directed by the N-N' axis, possibly accompanied by at least one magnetic core designed so that the field 12 is approximately oriented along the N-N' axis, that is to say in the same direction as that of said winding(s) at the front face 20 of the housing 25, or • of one (or more) winding(s) of turns whose mean plane(s) is / are directed by one (or more) axis(es) different from the N-N' axis, for example one (or more) winding(s) of turns whose mean plane is directed by the propagation axis A-A', and fitted with at least one magnetic core designed so that the field 12 is approximately oriented along the N-N' axis, that is to say along a direction different from said direction(s) of said winding(s).

[0076] In the preferred case where the primary unit has more than one magnetic pole 30, said magnetic poles 30 are arranged adjacently along the propagation axis A-A', possibly in an interlocking manner (i.e. with partial superposition), and are electrically connected to each other in series or in parallel according to the desired electrical specifications.

[0077] Particular embodiments of the magnetic pole(s) 30 will be described later.

[0078] Preferably, the magnetic poles 30 are arranged in pairs (of poles). Preferably, the magnetic poles 30 are grouped in at least two sets (two-phase assembly), and for example in three sets (three-phase assembly). Preferably, the number of magnetic poles 30 is high, so as to constitute a highly multipolar inductor in order to reduce the significance of the electromagnetic edge effects at the ends of said inductor.

[0079] 3.1.3. Electronic module for electrical energy conversion

[0080] The primary electronic module for electrical energy conversion 5 comprises one (or more) electronic board(s) including a plurality of electronic components forming in particular a primary electronic converter enabling the conversion of a direct current - from the means of supplying energy - into alternating current in order to supply the primary pole(s) with alternating current.

[0081] Such an electronic module is known to a person skilled in the art and will not be described in further detail hereafter.

[0082] 3.1.4. Electrical power supply module

[0083] The power supply means 4 make it possible to supply electrical energy to the magnetic pole(s) 30 of the primary unit 3 to generate the magnetic field 12 via the electrical energy conversion module 5. Of course The power supply means 4 also allow power to be supplied to all the electronic modules of the drive device, and in particular the auxiliary modules 5, 6, 7, 8, 9, when said modules of the drive device do not have their own power supply.

[0084] The energy supply means 4 include for example one (or more) electrochemical storage component(s), optionally rechargeable, such as one (or more) lithium ion battery(ies), or such as one (or more) supercapacitor(s).

[0085] Advantageously, the power supply means 4 can be integrated into the primary unit 3. In particular, the power supply means 4 can be housed in the casing 25 of the primary unit 3. This makes it possible in particular to improve the ergonomics of the drive device.

[0086] Alternatively, the power supply means 4 may be remote from the primary unit 3, said primary unit being electrically connected to said power supply means by means of connection such as cables, for example a set of cables attached to the housing 25, or for example a set of cables free from the housing 25 and connected to the primary unit 3 by means of lugs or a connector(s) attached to the housing 25.

[0087] Such means of supplying energy 4 being known to a person skilled in the art, they will not be described in further detail hereafter.

[0088] 3.1.5. Control Module

[0089] The control module 8 is configured to: • to control the electrical energy conversion module 5 and the auxiliary modules 4, 6, 7, 9, whether or not they are integrated into the housing 25 of the primary unit 3, • from the data received from the conversion module 5 and the auxiliary modules 4, 6, 7, 9.

[0090] In the following, we will speak interchangeably of "control module" or "controller" to refer to the control module 8.

[0091] Of course each module (conversion module 5 and auxiliary modules 4, 6, 7, 9) can have its own intelligence, that is to say its own controller which interfaces with the controller 8.

[0092] The controller 8 can be of any type known to a person skilled in the art; it includes, for example: • a component (or components) dedicated to computation, such as a processor (or processors), a microcontroller (or microcontrollers), a programmable logic controller (PLC), an application-specific integrated circuit (or integrated circuits), and / or other programmable circuits, • one (or more) memory(ies) which may be ROM or RAM memory (etc.), and may take the form of a (or) separate component(s) from said computing component(s), or be integrated directly into said computing component(s).

[0093] This (these) memory(ies) allows(s) the storage of: • program code instructions, such as an algorithm for real-time adjustment of the frequency and amplitude of the alternating current generated at the output of the primary converter, or • data, such as characteristic vehicle parameters or conversion modules 5 and auxiliary modules 4, 6, 7, 8, 9, or personalization data configured at manufacturing or configurable via a source external to the housing 25 (for example via a programmer), or machine learning data entered by the controller 8 during the life cycle of the drive device.

[0094] Preferably, the controller 8 is integrated into the housing 25. Alternatively, the controller 8 is remote from the housing 25 and is connected to it via wired or radio frequency link.

[0095] Examples of the operation of controller 8 will now be given by way of illustration, and some will be detailed later. For example, the control instructions for modules 5, 4, 6, 7, and 9 are updated based on data received from: • the human-machine interface module 9, for example when the brake lever is pressed, or when a button is pressed, for example on the handlebars, or when pedaling is detected by a pedal sensor located on the crankset, • the measuring means 6, for example the transmission of measurement data from sensors and received directly from said measuring means 6 or via the conditioning module 7, • the power supply module 4, for example information relating to the state of charge and / or the health status of said module, or other information from the battery manager (BMS, from the English "Battery Management System"\ • the conversion module 5, for example electrical measurements or information on switching performance, • the controller 8 itself, for example states of internal state machines (FSM, from the English “Finite State Machine”), or calculation results or estimates such as the relative speed of movement of the secondary unit 2 with respect to the primary unit 3.

[0096] Of course, many modes of operation and programming of the controller 8 are conceivable and the present invention is not limited to the examples described above.

[0097] 3.1.6. Measurement module

[0098] For the sake of clarity, the measuring means 6 have been represented by a single block in [Fig. 14], said block being positioned outside the housing 25 in [Fig. 15]. In practice, the measurement methods are numerous and include: • located near the primary unit 3 and for example in the housing 25, and / or • relocated to other areas of the vehicle at a distance from the primary unit 3, such as for example at the level of the crankset in the case of a pedal sensor or a torque sensor, and / or • integrated into an electronic module, such as for example in the BMS of the means of energy supply 4 or in the electrical converter 5 for measurements of an electrical nature.

[0099] Of course, such a simplification cannot limit the scope of the invention.

[0100] The measuring means 6 cover all the means known to man of the art of piloting an electric assist and will therefore not be described in more detail later.

[0101] The aforementioned list of sensors known to humankind in the state of the art shall be supplemented by: • a sensor capable of measuring the tension and / or displacement of a vehicle brake cable, and for example located at the level of the rim brake calipers (if the vehicle is equipped with such a braking system), and possibly integrated into the housing 25, or • a sensor capable of measuring a variation in hydraulic pressure in a hydraulic braking circuit of the vehicle, and for example located at the level of the disc brake calipers (if the vehicle is equipped with such a braking system), and possibly integrated into the housing 25.

[0102] One or the other of said sensors makes it possible to detect an action by the user to slow down the vehicle, and to inform the controller 8 so that it can adapt the control of the modules of the primary unit 3, for example: • by disconnecting the converter 5 from the magnetic pole 30 in order to eliminate induction and therefore drive, or • by configuring said converter 5 so that induction slows down the secondary unit 2 and recharges the storage components of the energy supply means 4.

[0103] In the first case the vehicle operates in "freewheeling" mode and braking is ensured by conventional means (for example, rim brakes or disc brakes).

[0104] In the second case the vehicle operates in "electrical energy recovery" (or "electrical energy dissipation") mode and braking is ensured in whole or in part by electromagnetic induction.

[0105] We will speak of "active braking" or "partially active braking" in the second case, and by analogy of "passive braking" in the first case.

[0106] 3.1.7. Conditioning Module

[0107] For clarity, the conditioning means 7 have been represented by a single block in [Fig. 14], said block being arranged inside the housing 25 in [Fig. 15]. In practice, the conditioning means are multiple and are: • located near the primary unit 3 and for example in the housing 25, and / or • integrated into the measuring means 6, for example when said means have a digital output capable of communicating directly with the controller 8, and / or • integrated directly into the controller 8, for example in the form of analog-to-digital converters (ADCs).

[0108] Of course, such a simplification cannot limit the scope of the invention.

[0109] The conditioning means 7 cover all the means known to those skilled in the art in the field of controlling an electric assistance system, and more generally in the field of embedded electronics, and will therefore not be described in further detail hereafter.

[0110] 3.1.8. Human-machine interface module

[0111] For the sake of clarity, the human-machine interface means 9 have been represented by a single block in [Fig. 14], said block being arranged inside the housing 25 in [Fig. 15].

[0112] In practice, there are multiple means of human-machine interfacing, including: • located near the primary unit 3 and for example in or on the housing 25, and / or • located close to the vehicle's control interface, for example at the handlebars on a bicycle.

[0113] Of course, such a simplification cannot limit the scope of the invention.

[0114] The rear wall 22 and / or side wall 21 of the housing 25 may, for example, include all or part of the human-machine interface means 9, for example one (or more) button(s) and / or one (or more) display(s).

[0115] For the sake of simplifying the presentation and by extension of the concept of human-machine interface, the rear 22 and / or side 21 walls of the housing 25 may also include electrical connection terminals integral with the housing 25, for example terminals or connector(s) (for example a female USB socket). The electrical connection terminals may, for example, be intended: • for charging, from an external source, the power supply means 4 if these are integrated into housing 25, and / or • to data communication with the electronic component(s) embedded in the housing 25, for example for debugging and / or parameterization purposes, or for firmware update purposes, and / or • to connection to external power supply means 4, for example to an external battery accessible on the vehicle if said power supply means are not on board the box 25.

[0116] The human-machine interface means 9 cover all the means known to a person skilled in the art in the field of controlling an electric assistance (buttons, displays, etc.), and will therefore not be described in more detail in the following.

[0117] 3.2. Secondary Unit

[0118] Unlike the primary unit 3, the secondary unit 2 constitutes a passive structure of the drive device. Thus, the secondary unit 2 is mounted on a moving part of the vehicle, and in particular on one of the wheels of the bicycle.

[0119] The magnetic field 12, radiated by the magnetic pole 30 of the primary unit 3, generates eddy currents by induction in secondary unit 2, and a tangential mechanical force is applied relative to secondary unit 2 and primary unit 3. Given the nature of the mechanical connection between the wheel and the vehicle, this mechanical force creates a mechanical torque around the axis of rotation of said wheel, and the vehicle accelerates (or decelerates). This mechanical torque can be added to the pedaling torque provided by the user and, for example, transmitted by the chain, thus assisting the user in moving the bicycle.

[0120] In the context of the present invention, "induction part" means a part intended to be the seat of said eddy currents, and which is integral with at least one element of the wheel of the vehicle.

[0121] Secondary unit 2 comprises one (or more) induction element(s). The induction element(s) is / are made of a material: • electrically conductive and preferably highly conductive, for example with an electrical conductivity greater than 10⁶ Siemens / meter and preferably greater than 10⁷ Siemens / meter, and • non-magnetic or weakly magnetic, in particular: • a material possessing paramagnetic properties such as aluminum, austenitic steel, titanium, etc., or • a material possessing diamagnetic properties such as silver, copper, or • a material with weak ferromagnetic properties, for example a material with a relative magnetic permeability of less than or equal to 10 and preferably less than or equal to 2, such as certain Nickel-Iron alloys.

[0122] The relationships linking the performance of induction phenomena with the electrical and magnetic characteristics of the material, and in particular the calculation and / or simulation of the skin thickness, are known to those skilled in the art and will therefore not be described in more detail in the following.

[0123] In the following, a material whose electrical conductivity is greater than or equal to 106 Siemens / meter will be called a “conductive material”.

[0124] In the following, a material whose relative magnetic permeability is less than or equal to 10 will be called a “non-magnetic or weakly magnetic material”.

[0125] This (these) induction part(s) may be a portion of a wheel component of the vehicle, or an "additional" part(s), that is to say, not necessary for the conventional operation of the vehicle. Thus, the induction part(s) may be: • integrated into the wheel, for example integrated: • in one (or more) cheek(s) of the rim, or • in one (or more) sidewall(s) of the tire, or • in the tire tread, etc.), • or intended to be mounted on a wheel component, for example fixed: • on one side of a rim cheek, or • on the spokes of the wheel, or • on the wheel hub, etc.

[0126] When the induction component(s) is / are integrated into the rim, the induction component(s) and the rim may be made of the same material, such as aluminum. In this case, the rim flange constitutes the induction component(s). Advantageously, a conventional rim can be retained without modification. Alternatively, the rim flange may have, over at least one angular portion of a wheel revolution, a thickness greater than the conventional thickness for the vehicle. Alternatively, or in combination, the rim flange may have, over at least one angular portion of a wheel revolution, a radial width greater than the conventional radial width for the vehicle.

[0127] In order to improve induction performance, the induction part(s), and in particular the wheel rim flange, may be equipped on their face with regarding primary unit 3, of one (or more) additional part(s) having high magnetic permeability, for example made of a ferromagnetic material with relative magnetic permeability strictly greater than 10 and preferably greater than 100.

[0128] Examples of additional ferromagnetic parts enabling channeling of the field generated by the primary unit will be described later.

[0129] 4. Technical description

[0130] Figures IA and IB are respectively a cross-sectional view and a front view schematically representing an example of a drive device, in which: • The secondary unit is the 200 flange of the wheel rim. In the following, and unless otherwise stated, the terms "secondary unit" and "rim flange" will be used interchangeably to refer to the secondary unit of a drive device according to the invention, although embodiments of the secondary unit are not limited to said road rim flange. • the primary unit is represented by a deformed parallelepiped 300, in the shape of a thick circular annular band (along the z-axis) and with an angular opening less than or equal to 360° (along the z-axis).

[0131] In [Fig. 1A], the primary unit 300 is arranged concentrically and opposite each other at an approximately uniform distance from a rim 200 of a bicycle wheel. More precisely, the outer face of the front wall of the primary unit housing faces the outer face of the rim flange. The primary unit and the rim are not fixed together and are arranged so that their respective positions remain approximately the same during rotation of the wheel, in directions other than those of the displacement resulting from the rotation.

[0132] In the context of the present invention and with reference to [Fig. 1A], the term "normal plane" means a plane directed by the z-axis, i.e., orthogonal to the z-axis, i.e., the imaginary mean plane of the front face of the primary unit 300, i.e., the face of the primary unit 300 opposite the secondary unit 200, at least temporarily over one wheel rotation. In the particular case of a flat rim flange, the mean plane of said flange is the plane in which the flange extends. It should be noted that, according to the invention, the normal plane is also approximately parallel to the mean plane of the secondary unit 200, i.e., to the mean plane of the rim flange in the case of the embodiment shown in [Fig. 1A]. The reader will appreciate that the z-axis illustrated in figures IA and IB, and the N-N' axis illustrated in [Fig. 15], are two identical axes, except that the N-N' axis of [Fig.15] is defined in relation to the secondary unit, whereas the z-axis of figures IA and IB is defined in relation to the primary unit.

[0133] Furthermore, in the context of the present invention, "air gap" means the space which separates the primary 300 and secondary 200 units when said units are facing each other (i.e. at least temporarily on one wheel revolution), and "air gap thickness" means the average distance along z (through the air gap) between the two facing faces of the primary 300 and secondary 200 units.

[0134] Finally, within the framework of the invention, "propagation axis" means a y-axis along which the tangential displacement of the secondary unit 200 is established with respect to the primary unit 300. The reader will appreciate that the y-axis illustrated in Figures IA and IB, and the A-A' axis illustrated in [Fig. 15], are two identical axes, except that the A-A' axis of [Fig. 15] is defined in relation to the secondary unit, while the y-axis of Figures IA and IB is defined in relation to the primary unit.

[0135] By way of illustrative but not limiting example, the primary unit illustrated in Figures IA and IB has: • an angular opening between 20° and 90°, and preferably between 30° and 70°, • a radial width between 100 millimeters and 500 millimeters, and preferably between 150 millimeters and 400 millimeters, • an average thickness (approximately along z on [Fig.1A]) between 5 millimeters and 100 millimeters, and preferably between 10 millimeters and 50 millimeters, • and an air gap thickness of between 0.5 millimeters and 10 millimeters, and preferably between 0.5 millimeters and 5 millimeters.

[0136] More generally, the dimensions of the primary unit 300 are defined according to the dimensions of the rim fitted.

[0137] In this example, in the front view of [Fig. 1B], assemblies 311 of insulated conducting wires are integrated into the primary unit 300, preferably arranged opposite the rim 200 forming the secondary unit, and in particular opposite the rim flange. These assemblies 311 are connected to each other so as to form coil assemblies approximately in the normal plane.

[0138] In [Fig. 1B], only the radial branches of the conducting windings are shown, and in particular the orthoradial branches connecting said radial branches are not detailed. By way of illustration and not limitation, the representation is limited to nine radial branch assemblies in [Fig. 1B]. In practice, a larger number of radial branch assemblies is preferred, particularly to reduce the significance of edge electromagnetic effects at the two orthoradial ends of the primary unit 300. The choice of the number of radial branch assemblies is within the grasp of those skilled in the art. It is, for example, defined by optimizing performance criteria as a function of several parameters, including the length orthoradial and radial width of the annular band of the primary unit 300, the dimension of the air gap, the electrical combination of the conductors with each other, and the range of linear displacement velocities of the secondary unit 200 relative to the primary unit 300. The electrical combination of the conductors with each other, and therefore the general shape of the turns formed by the windings, will be described later.

[0139] Figure IC is a side view of a bicycle wheel showing an example of positioning the primary unit 300, which has the general shape of a circular annular band as described above, opposite the rim 200 of a bicycle wheel 101. The methods of attaching the primary unit 300 to the bicycle will be described later.

[0140] In figures IA and IC, no portion of the conducting windings has been shown.

[0141] 4.1. Operation

[0142] The operation of the drive device of figures IA and IC will now be described in relation to [Fig.1B] which represents assemblies of radial branches of conductors.

[0143] In operation, the circulation of an alternating current IP is applied by electrical means in the conductors of the assemblies 311;. The circulation of the current IP in the conductors of the radial branches produces an electromagnetic field B having, in the absence of a rim 200, a distribution that varies according to the curvilinear abscissa 0. By way of non-limiting example, the frequency of the alternating current IP imposed in the conductors is less than 5 kHz, and is adjusted in real time, for example but not limited to, by means of a switching inverter according to control algorithms, for example over a frequency range below 500 Hz.The amplitude of the IP current depends on the electrical characteristics of the circuit, according to the electrical connections, and can be calculated based on the desired power input and the voltage range of the power supply, for example, but not limited to, a battery in the case of an electric bicycle. The injected electrical power will, for example, be less than 30 W, in order to provide what is called "moderate" assistance suitable for urban riding conditions (smooth pavement, slight incline, moderate speed), in contrast to the high-performance assistance systems of the state of the art, which are close to a substitute for pedaling or are adapted to severe riding conditions (steep inclines, rough terrain, high speed).However, this embodiment is not exclusive of other embodiments, and in particular of embodiments in which a greater power is injected, for example less than 1 kW, and for example less than 300 W if a single drive device equips a bicycle in . compliance with French standards governing the conditions of use of an electric assistance of less than 250 W nominal mechanical power.

[0144] When the electrically conductive rim 200 is positioned opposite the conductors of the radial spoke assemblies 311, the spatial distribution of the electromagnetic field B evolves as a function of the relative speed of movement of said rim with respect to said conductors, in addition to its evolution as a function of the imposed frequency of the alternating current IP. Another formulation considers that under the effect of the magnetic excitation generated by the flow of the current IP in the conductors of the primary unit 300, eddy currents appear in the rim 200, which constitutes the secondary unit, resulting in a modification of the spatial distribution of the electromagnetic field.These changes or variations in the spatial distribution of the electromagnetic field, which depend on the relative speed of the secondary unit with respect to the primary unit and on the frequency of the IP current, result, through induction, in the generation of a mechanical force between said primary and secondary units. By adjusting the frequency and amplitude of the IP current, control algorithms known to those skilled in the art allow the rim, and therefore the bicycle, to be accelerated or decelerated.

[0145] 4.2. General advantages of the invention

[0146] A first advantage of the invention lies in the absence of mechanical parts for the transmission of forces between: • the fixed reference frame (relating to the frame of the rolling vehicle, for example to the forks, stays or chainstays for a bicycle) and • the moving frame of reference (relative to the wheel).

[0147] The absence of contact makes it possible in particular to avoid the inconveniences linked to a degradation of said contact over time and / or according to the conditions of use (humidity, dust, etc.).

[0148] A second advantage of the invention lies in the direct nature of the drive, that is, the absence of a mechanical speed converter or reduction gear. This mechanical simplification provides an appropriate response to concerns relating to wear and maintenance, as well as the imperatives of reducing size and weight. For example, but not limited to, a device designed to provide moderate assistance (as defined above) makes it possible to equip a "muscular" or "classic" bicycle for daily use while minimizing the perceived sacrifice for the cyclist (essentially a moderate increase in weight).

[0149] A third advantage of the invention lies in the moderate constraints on the quality of the relative positioning of the primary unit with respect to the secondary unit, since the radiation of the magnetic field is maintained even if the characteristics of The air gap, and in particular the thickness of the air gap, varies and / or is not at its nominal values, unlike a contact coupling as in state-of-the-art solutions. In addition to the robustness provided during operation, such immunity of a drive device designed according to the invention guarantees the feasibility of mechanical solutions for attaching the primary unit to the bicycle, solutions that are both simple to install and simple to remove, at least partially. By way of non-limiting example, attachment methods consisting of two parts may be mentioned: • a first part attached to the primary unit casing, and • a second part designed to be attached to the bicycle, the first part being configured to attach to the second part removably using a quick-release locking element, for example, but not limited to, by press fitting, plugging, snapping, or screwing (quarter-turn lock). This not only allows for installation by a non-expert person with few or no tools, for example, in the case of retrofitting an existing vehicle, but also for occasional use by removing all or part of the device, for example, if one wishes to equip different vehicles alternately, or if one wishes to remove at least part of the device from the vehicle to prevent theft or vandalism by a third party, or to recharge the battery if it is integrated into the primary unit.It should be noted, however, that the implementation of the drive system is not limited to retrofit applications alone, and that, as an alternative, the system can also be integrated directly into the bicycle structure (sheaths, seat stays, chainstays) from the design phase.

[0150] A fourth advantage of the invention lies in the compatibility of the same primary unit model (mass-produced without customization) with a wide variety of vehicle variants, for example, but not limited to, a wide variety of bicycles. Indeed, rim dimensions, and to a lesser extent their shape, are generally based on a limited range of standards (650c, 700c, 26 inches, 27.5 inches (or 650b), 29 inches (or 700c), 24 inches, 20 inches). This compatibility advantage makes the invention suitable for retrofitting existing vehicles.It should be noted that further compatibility can be achieved, for example between rims of similar diameters and / or shapes, by implementing state-of-the-art primary unit mounting solutions that allow adjustment in at least one direction, for example, but not limited to, using a sliding mechanism, before being locked in place. As a non-exhaustive example, one could also temporarily insert... a shim between the primary unit and the rim (or more generally the secondary unit) during the installation of the device.

[0151] A fifth advantage of the invention lies in the possibility of performing a direct approximate measurement of the vehicle's speed (which is the linear speed of the secondary unit relative to the primary unit), that is to say, firstly, without requiring the installation of an additional remote sensor as may be necessary with certain prior art solutions, and secondly, without prior knowledge of the wheel diameter (or the gear ratios of any converter). This feature is particularly advantageous in the case of retrofit applications, where there is no prior knowledge of the vehicle to be equipped, whereas safety and regulations require control of the steering based on the vehicle's speed. This is, for example, the case with French regulations, which prohibit electric assistance for a bicycle above 25 km / h.The solutions for estimating or measuring speed will not be detailed here and are within the reach of a person skilled in the art, either through the electrical quantities at the terminals of the assemblies 311; or by adding a speed sensor integrated into the primary unit.

[0152] A sixth advantage of the invention lies in the possibilities it offers for designing a device that is more environmentally friendly and more economical than state-of-the-art solutions. Firstly, the absence of rare earth elements, in combination with mass savings (particularly in the case of moderate sizing as defined above), and the elimination of the additional remote speed sensor, each or in combination have favorable environmental and economic consequences. Secondly, it should be noted that in the case of moderate sizing as defined above, the passenger(s) of the vehicle will experience the assistance with a more "contained" level (as opposed to powerful assistance), making a higher level of torque imperfection (jerking) acceptable.This results in the possibility of implementing less constrained electronic and software control methods, therefore more environmentally friendly and / or more economical (fewer electronic resources in number and performance level), for example, but not limited to, on / off control with scalar V / f control. It should be noted that this sixth advantage provided by the invention contributes to the transition towards so-called soft mobility, by reducing the economic barrier to widespread adoption.

[0153] A seventh advantage of the invention lies in the possibility of recovering energy during braking, unlike some state-of-the-art solutions that have a freewheeling mechanism and / or a mechanical reduction or gear converter in their drivetrain. This opens the door to several applications, from increased range to supplementary or alternative electric braking. replacement of conventional friction braking solutions (pad, drum or disc).

[0154] [Fig.2] illustrates an equipment variant of a rim 200 in which two primary units 300 and 301 are installed approximately opposite each other, on either side of the rim 200. In [Fig.2], no portion of the conducting windings has been shown.

[0155] One advantage of the arrangement in [Fig. 2] is that it is possible to transmit twice as much power (or torque) to the wheel, and, for example, but not limited to, with a small additional cost in terms of electronic and control means if both sets of winding assemblies of the two primary units 300 and 301 are driven simultaneously. Another advantage of the arrangement in [Fig. 2] is that any axial electromagnetic forces applied to the rim 200 are canceled out (in the direction normal to the plane of the wheel). Finally, an arrangement according to the embodiment in [Fig. 2] ensures better static balance of the bicycle.

[0156] 4.3. Secondary Unit

[0157] Figures IA, IC and 2 have described particular and limiting examples of drive devices in which the secondary unit is the conducting rim 200 of the bicycle.

[0158] Various examples and more general embodiments of the secondary unit will now be described in relation to Figures 3A, 3B, 4A, 4B, 4C, 5A and 5B, which represent examples of bicycle wheels or wheel parts in relation to the invention.

[0159] As a preliminary point, it is important to note that the performance of the invention depends on the electromagnetic nature of the secondary unit with respect to the primary unit, for example, the electromagnetic nature of the rim in the case of Figures IA, IC, and 2. In these examples, the rim 200 is made of an electrically conductive material, preferably highly conductive, and non-magnetic or weakly magnetic, as described above. In particular, the material constituting the rim may be aluminum. Those skilled in the art will appreciate that aluminum rims are used on the majority of entry-level and mid-range bicycles and some high-end bicycles.

[0160] According to one embodiment, a primary unit can be fitted to such a rim as is, i.e., no modification to the rim is necessary. This embodiment is particularly advantageous in the case of a retrofit operation on an existing muscle bicycle.

[0161] According to the state of the art, the thickness of the bicycle rim flange is defined according to exclusively mechanical considerations, and generally results a compromise between mass and resistance to stress. The thickness of the rim flange is generally uniform over a wheel rotation and on the order of a millimeter. According to another embodiment, the rim is provided in which at least one radial portion of at least one of its flanges is thicker than the thickness required for its mechanical strength over an orthoradial length less than or equal to 360°, for example, a thickness between 1 and 10 millimeters, preferably between 2 and 5 millimeters. An advantage of this embodiment is to strengthen the induction in the rim, and consequently to improve the overall electromechanical performance of the drive system.

[0162] According to the state of the art, the radial width of a rim flange is defined primarily by mechanical considerations, possibly aesthetic ones, and generally results from a compromise between mass and resistance to stress. Its dimensions may also address brake pad friction surface requirements. The radial width of a rim flange is generally uniform around a wheel rotation and is on the order of ten millimeters on entry-level and mid-range rims. In another embodiment, a rim is provided in which at least one orthoradial portion of at least one of its sidewalls has a radial width greater than the radial width required for its mechanical strength or for brake pad friction surface considerations, for example, a width between 15 and 150 millimeters, preferably between 15 and 50 millimeters.The radial dimensions of the primary unit 3 positioned opposite said rim will be advantageously adapted, and in particular increased compared to the dimensional range described in Figures IA and IB. An advantage of this embodiment is to increase the induction surface in said rim, and consequently to improve the overall electromechanical performance of the drive device.

[0163] Figure 3A is a cross-sectional view of a rim 201 in relation to a primary unit 300, schematically representing a rim adapted according to another embodiment to allow for a performance gain. The air gap between the primary unit 300 and the secondary unit (i.e., the rim flange 201 in the example) is, for instance, defined according to the embodiments described above.

[0164] In the example of [Fig. 3A], the rim 201 includes an additional magnetic field containment piece 210. The material constituting this additional piece 210 is advantageously ferromagnetic, that is to say, it has a relative magnetic permeability strictly greater than 10 and preferably greater than 100, and is, for example, electrical steel, magnetic stainless steel, a low-nickel iron-nickel alloy, etc., that is to say, for example, a material widely used in transformers and machines electric for low cost and good magnetic properties. In this example, the additional part 210 has the shape of a slightly axially deformed annular plate and is disposed on the inner face of the rim cheek 201. The face of the additional part 210 closest to the primary unit 300 is preferably approximately flush against the inner face of the rim cheek 201, and therefore also approximately parallel to the front wall of the primary unit 300 housing. The additional field-containing part 210 is preferably disposed along the entire orthoradial length of the rim 201, and preferably has a constant cross-section along this curvilinear abscissa.By way of illustration, but not limitation, the additional part 210 is, for example, cut from a sheet of rolled ferromagnetic material with a thickness between 1 and 10 millimeters, preferably between 1 and 5 millimeters, and a radial width chosen to approximately cover the available radial width on the inner face of the rim flange. The additional part 210 is, for example, fitted into grooves provided for this purpose on the inner face of the rim flange. It is not necessary for the additional part 210 to be made continuously; it can very well consist of a succession of separate magnetic sections assembled adjacently along the curvilinear abscissa.Nor is it necessary for these successions of sections to be arranged continuously, that is to say in a joined manner (each section being in contact with the sections directly adjacent to it), even if a pseudo-continuous arrangement leads to a performance gain.

[0165] According to the embodiment of [Fig. 3A], the magnetic field lines passing through the thickness of the rim 201 are channeled by the additional part 210, which thus closes the field circuit, reducing reluctance and improving electromagnetic coupling. A drive device incorporating a rim adapted according to this embodiment therefore offers an advantage in terms of overall performance.

[0166] [Fig.3B] illustrates a variant of the embodiment described in [Fig.3A], in which a rim 202 is adapted with two additional parts 210 and 211 so as to work with two primary units 300 and 301, installed approximately opposite each other, on either side of the rim 202. This embodiment combines the advantages of the embodiment shown in [Fig.3A] with the advantages of the embodiment shown in [Fig.2].

[0167] Figures 4A, 4B and 4C are three side views of a wheel 101 adapted according to three other embodiments, for example, to allow for a performance gain. In Figures 4A, 4B and 4C, the primary unit of each drive device is not shown, but its positioning is within reach of The expert. A wheel 101 is composed of a hub 103, spokes 102i, a rim 200 and a tire 230.

[0168] As described above, an "induction part" is understood to be a conductive, non-magnetic or weakly magnetic part in which at least one winding of the primary unit 300 can induce eddy currents, and which is integral with at least one element of the vehicle wheel. An induction part may be: • an existing portion of a vehicle component, such as, for example but not exclusively, the wheel rim flange in the embodiments described above, or • an "additional" part, that is, a part not necessary for the conventional operation of the vehicle. Examples of the manufacture of these additional parts will now be presented.

[0169] In the example of [Fig.4A], the secondary unit consists of an induction piece 220 positioned concentrically to the wheel 101. This induction piece 220 is made of an electrically conductive and non-magnetic or weakly magnetic material (i.e. diamagnetic, paramagnetic or with weak ferromagnetic properties), for example made of aluminium.

[0170] In the example of [Fig.4A], the induction piece 220 has the form of an annular plate fixed securely with at least one radius 102; the face of the induction piece 220 facing the primary unit 300 being preferably approximately parallel to the plane of the wheel 101, and parallel to the front wall of the primary unit 300.

[0171] In the example of [Fig. 4A], the induction element 220 forms a ring, that is, it is continuous along the entire orthoradial length of the rim 200, and preferably has a constant cross-section along this curvilinear abscissa. By way of illustration, but not limitation, the induction element 220 is, for example, cut from a sheet of aluminum with a thickness between 1 and 20 millimeters, preferably between 1 and 5 millimeters, and a radial width chosen in relation to the dimensions of the primary unit 300, and more particularly to the mechanical power that is to be delivered to the bicycle. The induction element 220 is, for example, but not limited to, fixed to three spokes 102 of the wheel by means of a snap-fit ​​system of the secondary unit.The induction element 220 does not need to be made continuously; it can perfectly well consist of a succession of separate conductive sections assembled along the curvilinear abscissa. Nor does it need to be arranged continuously, i.e., joined together, even though a pseudo-continuous arrangement leads to a performance gain.

[0172] According to the embodiment of [Fig. 4A], the field radiated by the windings of the primary unit 300 positioned opposite at least a part of the part Induction coil 220 generates eddy currents in said induction coil 220 and therefore exerts a force on it by electromagnetic induction. A motor or brake torque is thus applied to the wheel 101.

[0173] One advantage of this embodiment lies in the fact that it allows for the equipping of rolling vehicles whose rim flanges have electrical and / or magnetic characteristics incompatible with the desired induction performance. Another advantage of this embodiment is that it allows the transmitted power to be sized independently of the rim characteristics, and without modifying the rim itself. A further advantage of this embodiment is that it offers improved compatibility since the average radius of the drive device does not depend on the average diameter of the rim.Another advantage of this embodiment is that it allows, to some extent, the adjustment of the range of relative linear speeds of the secondary unit with respect to the primary unit (in m / s), depending on the average radius at which the induction element is positioned. This can provide an advantage in the range of driving frequencies for the electrical current IP injected into the windings of the primary unit. Indeed, a drive device according to the invention incorporating an induction element positioned at a reduced average radius compared to that of the rim, as described in [Fig. 4A], will implement lower electrical frequencies for the same angular speed of the wheel (in radians / s), compared to embodiments in which the rim forms the secondary unit.

[0174] Figure 4B illustrates a variant of the embodiment described in Figure 4A, in which a wheel 101 is fitted with several induction parts rather than just one. In this particular example, the wheel 101 comprises, by way of illustration and not limitation, three induction parts 2211, 2212, and 2213, derived as portions of the induction part 220 of the embodiment in Figure 4A. An advantage of this embodiment is that it allows the increase in the wheel's mass to be limited without reducing either the thickness or the radial width of the induction parts. This advantage is particularly relevant in the case of moderate dimensioning as defined above, since the residual torque surges will be little or not at all felt by the user of the moving vehicle.

[0175] Figure 4C illustrates a variant of the embodiment described in Figure 4A, in which a wheel 101 is adapted with a secondary unit no longer fixed to the spokes 102i, but to the hub 103 of said wheel. An advantage of this embodiment lies in the simplicity and / or robustness of the attachment. Like the embodiment described in Figure 4A, the embodiment described in Figure 4C has the additional advantage of implementing lower relative linear speeds and therefore lower electrical frequencies compared to embodiments in which the rim forms the secondary unit.

[0176] According to another embodiment, a wheel 101 is adapted with an induction element no longer fixed to the hub 103 of said wheel, but to the rim 200, for example, but not limited to, by means of a mounting system for the secondary unit. Similar to the embodiment of [Fig. 4C], this new embodiment offers the advantage of simplicity and / or robustness of the mounting.

[0177] Figures 5A and 5B are two cross-sectional views of two tires adapted according to two other embodiments, for example, to facilitate installation. In Figures 5A and 5B, primary units 301 and 302 are curved and positioned so that the air gap is defined, for example, according to the embodiments described above.

[0178] In the example of [Fig. 5A], the tire 231 includes an induction piece 232 forming the secondary unit. This induction piece 232 is positioned concentrically with the tire 231 and is made of an electrically conductive and non-magnetic or weakly magnetic material, such as aluminum. More precisely, the induction piece 232 has approximately the general shape of the tread of the tire 231, that is, approximately the general shape of a cylinder with a high aspect ratio and slightly ovalized, meaning that it is continuous along the entire orthoradial length of the tire 231, and preferably has a constant cross-section along this curvilinear abscissa.The induction element 232 is, for example, cut from an aluminum sheet with a thickness between 1 and 5 millimeters, preferably between 1 and 3 millimeters, and an axial width between 10 and 50 millimeters, preferably between 10 and 20 millimeters, this value being chosen in particular according to the dimensional characteristics of the tire 231. The induction element 232 can be overmolded into the tire 231. Depending on the sizing criteria, the element 232 can be axially widened and ovalized so as to cover all or part of the tire sidewalls. As illustrated in [Fig. 5A], the primary unit is also ovalized to maintain an approximately uniform air gap thickness according to the embodiments described above. It is not necessary for the induction element 232 to be produced continuously.The induction element can notably consist of a succession of distinct conducting sections assembled along the curvilinear abscissa. It is also not necessary for these successions of sections to be arranged continuously, i.e., joined together, even though a pseudo-continuous arrangement leads to a performance gain.

[0179] Fig. 5B illustrates a variant of the embodiment described in Fig. 5A, in which a tire 233 is fitted with an induction piece 234 approximately in the shape of an annular plate positioned at one of the sidewalls of the tire.

[0180] The embodiments described in Figures 5A and 5B offer the advantage of being able to adapt a wheel more simply than by modifying certain characteristics of its rim, that is, simply by changing the tire. This advantage is particularly well-suited to retrofit applications. For example, one or the other of the two embodiments will be chosen depending on the integration and mounting constraints of the primary unit on the vehicle. The embodiment described in [Fig. 5B] has the additional advantage of being adaptable to two drive devices according to the invention, in line with the embodiments described in Figures 2 and 3B, and consequently offering the same advantages.

[0181] Other embodiments will now be described as variants of the embodiments presented above. The positioning of the primary unit is within the capabilities of a person skilled in the art.

[0182] One embodiment involves using the brake disc as the induction component in the case of a vehicle equipped with such a braking system. This embodiment is particularly suitable for an aluminum alloy disc, or for a disc made of non-magnetic or weakly magnetic stainless steel, for example, austenitic stainless steel. This embodiment is particularly advantageous for retrofitting applications.

[0183] Another embodiment consists of using as an induction component at least one chainring or pinion already present on the rolling vehicle, or adding an additional conductive and non-magnetic or weakly magnetic disc to the pedal assembly to act as an induction component. This embodiment may, for example, be advantageous for certain retrofit applications.

[0184] Another embodiment involves inserting an induction element into the sidewall of a non-conductive rim, for example, a carbon fiber rim. This embodiment may also be advantageous for certain retrofitting applications.

[0185] Another embodiment consists of using as an induction element the inner cylindrical surface of a hubless wheel, for example as described in patent KR102625328B1. This embodiment may, for example, be advantageous for unconventional wheel configurations.

[0186] Various examples and embodiments with various variants have been described above. It should be noted that a person skilled in the art can adapt or combine various elements of these various examples, embodiments, and variants without having to demonstrate inventive step. It should be noted in particular that a single drive device described above can equip a rolling vehicle, or that it can be combined in whole or in part with other drive devices as required by the application. It should also be noted that the induction components (i.e., additional component) and the field containment component (i.e., additional component) can be combined for each mode of Implementation. It should also be noted that the embodiments and variants described in this application can be adapted to other magnetic field configurations, and for example to pseudo-radial orientations of said field rather than pseudo-axial orientations as presented, or to configurations combining a pseudo-axial component and a pseudo-radial component of said field. Adapting the examples and embodiments described in this application to other types of drive devices is within the scope of those skilled in the art and will therefore not be detailed below.

[0187] 4.4. Primary Unit

[0188] Various examples and embodiments of primary unit windings will now be described with reference to Figures 6 and 7, which represent examples of conductor windings.

[0189] Fig. 6 is a front view of a primary unit, schematically and partially representing an example of electrical connection typology between assemblies 311; of radial branches of conductors.

[0190] In [Fig. 6], two assemblies 312 and 3122 of orthoradial branches connect two assemblies 311 and 3114 of radial branches, at a spatial frequency of one assembly in three, forming a set of turns defined as an electromagnetic "pole" according to the terminology of electric motors. For clarity, only two assemblies 312 and 3122 of orthoradial branches have been shown in [Fig. 6], and this illustration represents short-circuited turns solely to highlight the concept of an electromagnetic "pole". By extrapolation, [Fig.6] would represent an electromagnetic pattern with three interlaced poles (311; / 3114, 3112 / 3115, 3113 / 3116), and more precisely with three pairs of poles (311; / 3114 / 3117, 3112 / 3115 / 3118, 3113 / 3116 / 3119), as will now be described with the help of the illustration in [Fig.7] which represents an example of connections more faithful to reality, between the assemblies of radial branches of conductors.By way of illustrative but not limiting examples, electromagnetic poles may consist of varnished copper wires wound in the slots of a laminated ferromagnetic core, or for example arranged in and on the same dielectric support in the form of a plate a few hundred micrometers to a few millimeters thick, for example a PCB (Printed Circuit Board) type support possibly with a ferromagnetic core.

[0191] For the sake of simplicity, the embodiments described in the present invention are limited to the particular case where the direction of the radiated magnetic field The direction of the turns is not modified by the magnetic field circuit. Implementing such a field circuit can offer certain advantages, for example in terms of size, especially if the mean plane of the turns is directed along the propagation axis y instead of the normal axis z. Since such methods of designing and optimizing a field channeling inductor are known to those skilled in the art, they will not be described in further detail hereafter.

[0192] In [Fig. 7], twelve assemblies 313, 314, and 315 of orthoradial branches, with i ranging from 1 to 4, connect all or part of the nine assemblies 311 to 3119 of radial branches, with a spatial frequency of one assembly in three, as in the embodiment described in [Fig. 6], forming three sets of turns, or three pole pairs according to another prior art formulation. Each conductor assembly (of radial or orthoradial branches) has been represented by a single line for clarity. Each set of turns has two electrical access terminals 323+ / 323-, 324+ / 324-, and 325+ / 325-. The direction of the connections (serial / anti-serial), as well as the arrows representing the direction of flow of the IP current, make explicit the notion of "pole pair" in the sense of the state of the art.However, the distinction of six independent electrical access terminals does not in any way prejudge their connection to electronic control systems, nor their possible connection to each other, for example according to a three-phase star architecture.

[0193] One advantage of the embodiment described in Figures 6 and 7 is that it allows the implementation of standard three-phase converters in the electric motor industry. A further advantage of a three-phase architecture lies in the fact that the radiated magnetic field can be spatially shaped in a relatively sinusoidal manner, which notably reduces torque imperfections and the spectral richness of the electric currents.

[0194] A variant of the embodiment described in Figures 6 and 7 consists of implementing a two-phase architecture made up of two sets of turns (instead of three), that is to say, in which all or part of the 31L radial branch assemblies are connected to each other with a spatial frequency of one assembly out of two. This type of architecture can offer certain economic advantages, in particular due to the simplification of the electronic control means for two bridge arms, or even a single bridge arm, by implementing known prior art methods.

[0195] More generally, the number of phases of the primary unit can be advantageously adapted according to the sizing of the electrical control means, for example by adapting the width or the number of pole pairs while maintaining the same overall size of the primary unit along the propagation axis.

[0196] In Figures 6 and 7, the number of poles shown is greatly reduced for clarity, but the described drive device can accommodate a large number of pole pairs, determined according to the dimensional, dynamic, and electrical characteristics of the system, and may, for example, result from the optimization of performance criteria. It should be noted that the number of pole pairs can be chosen, in particular, based on considerations of the frequency range of the physical quantities being manipulated, it being understood that the narrower the pole width, the wider the frequency range of the currents and fields for the same relative linear speed of the secondary unit with respect to the primary unit.

[0197] The electrical connection examples presented above are not exclusive of variants of wiring topologies known in the state of the art, and the choice may for example result from an optimization of performance criteria (cost, mass, volume, etc.) according to the characteristics of the rolling vehicle (dimensions, speed, etc.).

[0198] The control algorithms adapted to a drive device according to the invention are referenced in the prior art as algorithms for controlling a "slip" (between a rotor and a stator), or more generally as algorithms for controlling asynchronous machines. They fall into two families: • scalar controls on the one hand, including constant flux control also called V / f control, and • Vector controls on the other hand, including control by rotor flux orientation.

[0199] It should be noted here that in the case of moderate sizing as defined above, the user's perception of the assistance will be "contained" (as opposed to powerful assistance), making a higher level of torque imperfection (jerking) acceptable. In a particular embodiment, on / off control with scalar V / f control will be used, which has the advantage of relying on less constrained electronic and software control methods, thus being more environmentally friendly and / or more economical (fewer electronic resources in terms of both number and performance level).

[0200] For the sake of clarity, the description of the primary unit has thus far been limited to its electrical windings. It should be noted that in practice the primary unit is not limited to these windings, but may in particular include control means and / or means for converting electrical energy and / or means for supplying energy.

[0201] Figure 8 is a side view of a drive device according to the invention, schematically representing a particular embodiment. In [Fig.8] no portion of the conducting windings has been shown.

[0202] In the example of [Fig. 8], the primary unit 303 is composed of three elements 322, 321, and 320 joined together and assembled in that order as one moves away from the induction element, here represented by a rim. In this example, the three elements 322, 321, and 320 are schematically represented by three layers, each in the shape of an annular strip, the orthoradial lengths of each of the three elements not necessarily being identical. According to this embodiment, the intermediate element 321 represents the assembly of electrical windings forming the electromagnetic poles described above, and, for example, fitted with a ferromagnetic core. The element 320 furthest from the induction element represents the assembly of electronic measurement and control boards, for example, fitted with battery cells or supercapacitors capable of exchanging electrical energy with said electronic boards.The element 322 closest to the induction part is a protective layer combining, for example, the functions of mechanical protection of the elements of the primary unit against the risks of abrasion by the secondary unit, electrical insulation, and / or sealing.

[0203] As described above, element 322 is for example the front wall 20 of a housing 25 which more generally protects all or part of the primary unit.

[0204] According to a variant of the embodiment described in [Fig. 8], the element 322 is made of a flexible material such as caliper brake pad rubber. According to this embodiment, the primary unit 303 is left mobile, for example in a configuration close to that of a brake caliper, i.e., it has a degree of freedom relative to the vehicle rolling approximately in rotation about the y-axis, advantageously allowing all or part of the friction braking function to be retained in addition to the presence of the drive device, for example, but not limited to, for situations of heavy braking or as a safety backup to the electromagnetic braking function.

[0205] According to another variant, the rubber is fixed to at least one of the orthoradial ends of the primary unit, in order to ensure said friction braking function outside the induction zone, which may for example be advantageous if a reduced thickness air gap is desired.

[0206] According to another embodiment, the conventional caliper brake pads are retained and move independently of the primary unit 303. This embodiment has the advantage of completely dissociating the motor / brake function of the device according to the invention from the conventional friction braking function.

[0207] According to another embodiment, all or part of the primary unit 303 has one degree of freedom with respect to the vehicle rolling approximately in translation about the z-axis, and the primary unit 303 includes a system for maintaining the thickness of the air gap, for example but not limited to by means of at least one roller whose the tread is in contact with the rim, possibly with a mechanical return system to maintain said contact regardless of the conditions of use or deformation of the rim.

[0208] Various examples and methods of attaching the primary unit will now be described with reference to Figures 9, 10A to 10D, 11A to 11D, 12A to 12E, and 13A to 13C, which schematically and partially represent examples of bicycle drive devices related to the invention. In Figures 9, 10A to 10D, 11A to 11D, 12A to 12E, and 13A to 13C, no portion of the conductive windings is shown.

[0209] Figure 9 is a side view showing an example of the installation of a first primary unit 304A of a first device opposite a front rim 200A of a bicycle, and an example of the installation of a second primary unit 304B of a second device opposite the rear rim 200B of the same bicycle. In the example in Figure 9, each primary unit 304A and 304B has the general shape of a circular annular band as described above, and is fixed to the mounting tabs of the rim brake calipers located on the fork and the rear triangle of said bicycle.

[0210] One advantage of this embodiment lies in the simplicity of attaching the primary unit to the rolling vehicle, which is particularly, but not exclusively, suited to retrofit applications, since most entry-level and mid-range bicycles are equipped with brake caliper mounting brackets. This advantage is all the more important as these mounting brackets are generally positioned according to dimensional standards common to most bicycles (in order to allow compatibility between the different braking systems on the market). This embodiment therefore offers a significant advantage in terms of the compatibility of the same primary unit model with a wide range of bicycles.

[0211] According to one embodiment, at least one brake cable can be used to send a mechanical command to the control electronics, in the form of the cable's displacement and / or in the form of a tension force on the cable. Several examples of embodiments using a brake cable as a propagation medium will now be described in an illustrative but not exhaustive manner, as the alternatives are numerous and within the grasp of those skilled in the art.

[0212] According to one embodiment, light pressure on at least one brake lever is interpreted as a command to activate the drive, while stronger pressure is interpreted as a braking command. By way of a limiting but not exclusive example, in the case where the bicycle is equipped with brake pads, the transition threshold from light pressure to strong pressure is the threshold at which at least one of said The brake pads come into contact with the rim and create a counter-reaction force on the brake cable.

[0213] According to another embodiment, a particular sequence exerted on at least one brake lever, such as press / release / press / release by way of illustrative but non-exclusive example, is interpreted by the control means of the device as an activation command for the drive, while retaining the mechanical friction braking command in the case of regular pressure not correlated with the particular sequence retained.

[0214] The advantage of these embodiments is that they minimize the modifications required to a bicycle to equip it with a drive device according to the invention, particularly, but not exclusively, in the case of retrofit applications. An additional advantage resulting from the use of a brake cable as a propagation medium is that it allows the control algorithms to have complete information on the cyclist's intention, namely, on the one hand, the activation command for the drive device and, on the other hand, the command for the braking system. Such information can, in particular, make it possible to deactivate the device in the event of a braking command, or to use the device in alternator mode to brake the wheel by electromagnetic induction as a substitute for, or in combination with, conventional mechanical brakes.The technical solutions for dissipating or recovering braking energy electrically are within the grasp of those skilled in the art and will not be described.

[0215] These embodiments are particularly suited to certain variants of embodiments described around [Fig.8], and in particular those in which a part made of a rubber material similar to that of caliper brake pads is present on the primary unit near the rim cheek.

[0216] According to one embodiment, the commands are mechanically transmitted to the hydraulic circuit of a disc brake system. Another embodiment uses wireless transmission, for example, but not limited to, by means of a button or a mechanical or electronic dimmer, for example, located on the handlebars of the bicycle. In yet another embodiment, the assistance is automatically activated by the control electronics based on a software estimate and / or measurements, for example, from an estimate of the pedaling torque or from its measurement by a torque sensor at the bottom bracket. In all the described embodiments, the control can be combined with a pedaling sensor according to the state of the art, for example, a pedaling detection sensor when required by regulations, or for example, a torque sensor for improved user experience.

[0217] Figure 1OA is a front view of a bicycle rear triangle, showing, in particular, the seat stays 104i and 1042, as well as the mounting bracket 105 for the rear rim brake calipers. Figure 1OB is a view of the same rear triangle, on which an assembly 304B of two primary units has been installed according to one of the embodiments of Figure 9 and according to all or part of one of the embodiments described in Figures 2 and 3B. In the example of Figure 1OB, the assembly 304B of the two primary units is fixed at the mounting bracket 105 for the rear rim brake calipers.

[0218] Figure 1OC is a front view of a bicycle front fork, showing in particular the fork legs 106i and 1062, as well as the mounting tabs 107i and 1072 of the front brake calipers. Figure 1OD is a view of the same front fork, on which an assembly 304A of two primary units has been installed according to one of the embodiments of Figure 9 and according to all or part of one of the embodiments described in Figures 2 and 3B. In the example of Figure 1OD, the assembly 304A of the two primary units is fixed at the mounting tabs 107i and 1072 of the front brake calipers.

[0219] In the examples in Figures 10B and 10D, the assemblies 304B and 304A of primary units have been schematically represented as a single block for clarity. Certain embodiments, and in particular those in which it is sought to maintain some mobility of at least one primary unit relative to the moving vehicle, for example, but not limited to, for the purpose of implementing a friction braking function, will require adaptation within the grasp of those skilled in the art. In particular, according to an illustrative but not limiting embodiment, the assemblies 304A and 304B of primary units are fixed respectively to the brake caliper mounting lugs 105 and 107 / 1072 by means of a pivot joint system similar to that of a conventional mechanical brake caliper assembly.Adapting such methods of fastening assemblies of primary units to methods of fastening a single primary unit is within the scope of those skilled in the art and will not be described here. More generally, other solutions for fastening an assembly of one (or more) primary unit(s) exist but will not be described here as they are within the scope of those skilled in the art.

[0220] Figures 1 IA to 11D are schematic perspective views of examples of assemblies 305B, 306B, 305A and 306A of primary units in relation to Figures 10B and 10D. In Figures 11A and 11B, the assemblies 305B and 306B of primary units are fixed to the rear axle bracket 105 through the opening 330, and the rear wheel is inserted between the two primary units of each assembly 305B and 306B at the wheel arch 340. In Figures 1 IC and 11D, the assemblies Primary units 305A and 306A are fixed to the front axle lugs 107i and 1072 through openings 33h and 3312, and the front wheel fits between the two primary units of each assembly 305A and 306A at the wheel arch 341.

[0221] Figures 1 IA to 11D will now be described in relation to the illustration in [Fig.8].

[0222] In the example of [Fig. 1 IA], and according to the embodiment of [Fig. 8], each primary unit of the assembly 305B has two layers 321F and 322F that are orthoradially more extensive than the layer 320F at one end of the assembly 305B, the layers 321F and 322F preferably extending identically between the two orthoradial ends of the assembly 305B of the device. One advantage of this embodiment is that it allows the partial insertion of the primary units between the stays 104i and 1042, as shown, for example, in the illustration of [Fig. 9].

[0223] In the example of [Fig. 1 IB], each primary unit of the assembly 306B has two layers 321G and 322G extending orthoradially on either side of the layer 320G, the layers 321G and 322G preferably extending identically between the two orthoradial ends of the assembly 306B. One advantage of this embodiment is, in particular, to allow a reduction in mass or size.

[0224] The examples in Figures 1 IC and 11D illustrate two adaptations to a front wheel, of the two embodiments described for a rear wheel respectively in Figures 11A and 1 IB. In Figures 1 IC and 11D, the assemblies 305A and 306A of primary units are fixed to the lugs 107i and 1072 of the front axle through the openings 3311 and 3312, and the front wheel is inserted between the two primary units of each assembly 305B and 306B at the wheel arch 341.

[0225] Various examples and methods of positioning at least one primary unit relative to the frame of the rolling vehicle will now be described with reference to Figures 12A to 12E and 13A to 13C, which represent bicycle front and rear axles equipped with drive devices related to the invention. In Figures 12A to 12E and 13A to 13C, the windings described above in the various embodiments are not shown. Neither the wheel nor the induction component(s) are shown in Figures 12A to 12E and 13A to 13C, but their relative positioning is readily apparent to those skilled in the art.

[0226] In Figures 12A to 12E and 13A to 13C, the fastening elements are not shown, but their design is within the grasp of those skilled in the art. It should be noted here that the invention guarantees the feasibility of mechanical solutions for fastening the primary unit, which are both simple to install and simple to remove, at least partially. As a non-limiting example, a primary unit decomposed into two parts has been mentioned above, the first removable part of which is coupled by means of a quick-locking system to a second support part permanently fixed to the rolling vehicle.

[0227] In the example of [Fig. 12A], the primary unit 350B is fixed to one of the stays 104i. In the example of [Fig. 12B], the primary unit 351B is fixed to one of the bases 108i. In the example of [Fig. 12C], the primary unit 352B is fixed to both one of the stays 1041 and one of the bases 1081. In the example of [Fig. 12D], the primary unit 353B forms a complete disc fixed at the axle 103B. In the example of [Fig. 12E], the primary unit 354B forms a portion of a disc fixed at the axle 103B. For each of the figures 12A to 12E, the primary unit is preferably fixed on the opposite side to the transmission chain, or on both sides if two drive devices coexist approximately face to face according to a variant of the embodiments described in figures 2 and 3B.

[0228] In the example of [Fig. 13A], the primary unit 355A is fixed to one of the sleeves 106i. In the example of [Fig. 13B], the primary unit 356A forms a complete disc fixed to the axle 103A. In the example of [Fig. 13C], the primary unit 357A forms a portion of a disc fixed to the axle 103A.

[0229] The described embodiments are not, however, limited to these particular cases. As an alternative, the primary unit may be positioned in a different area than those described in the embodiments above, and / or fixed in a different way. As an alternative, the side (and the windings) of the primary unit facing the rim flange may not be flat, nor necessarily curved to exactly follow the general shape of the rim flange or, more generally, of the induction element, and may, for example, extend radially beyond the rim or the induction element on at least one of its edges.

[0230] 5. Conclusions

[0231] Various examples and embodiments with various variants have been described above.

[0232] It should be noted that a person skilled in the art may adapt or combine various elements of these various examples, embodiments and variants without demonstrating inventive activity.

[0233] It should be recalled in particular that a single drive device described above can equip a rolling vehicle, or that it can be combined in whole or in part with other drive devices according to the needs of the application.

[0234] It should also be noted that the primary unit of a drive device described above can alternatively: • to incorporate all the elements necessary for its operation, namely the electronic and electrochemical means in addition to the electromagnetic means, in order to present itself to the user or installer in the form of a self-contained unit, or • to include only part of the means of implementation, and for example to have electrical connection terminals on one side of the box capable of connecting said primary unit to external means available on the vehicle.

[0235] Finally, it should be recalled that the modes and variant embodiments described in this application can be adapted to other configurations of the magnetic field, and for example to configurations with pseudo-radial orientation of said field rather than configurations with pseudo-axial orientation as presented, or to configurations combining a pseudo-axial component and a pseudo-radial component of said field.

[0236] The adaptation of the examples and embodiments described in this application to other types of training devices is within the scope of a person skilled in the art and will therefore not be detailed below.

[0237] Thus, the reader will have understood that many modifications can be made to the present invention without materially departing from the new teachings presented here.

[0238] Consequently, all modifications of this type are contained within the scope of the attached claims.

Claims

1.

2. Demands An electric assistance device for a vehicle comprising at least one wheel, configured to be powered by electrical power supply means (4) in order to enable the rotation of said and at least one wheel, and characterized in that the electric assistance device comprises: • a primary unit (3) suitable for being fixed to a frame (10) of the vehicle - such as a steering component, for example a fork, or such as a chassis, for example a frame, the primary unit including at least one primary magnetic pole (30), said and at least one primary magnetic pole being adapted to generate a magnetic field (12) from electrical energy supplied by the electrical energy supply means (4), • a secondary unit (2) capable of being: • fixed to said and at least one wheel, or • integrated into said and at least one wheel, the secondary unit including at least one induction element, said and at least one induction element being made of a material: • with an electrical conductivity greater than 10⁶ Siemens / meter and preferably greater than 10⁷ Siemens / meter, and • of relative magnetic permeability less than or equal to 10 and preferably less than or equal to 2, the primary and secondary units being configured to face each other at least temporarily over one wheel revolution, the primary and secondary units extending opposite each other through an air gap (13) of average thickness between 0.5 millimeter and 10 millimeters when they face each other, so that when the wheel moves in rotation, the magnetic field generated by said and at least one primary magnetic pole induces a mechanical torque in a direction of rotation of the wheel at least temporarily over one wheel revolution. Electric assistance device according to claim 1, wherein the vehicle is a bicycle, and wherein a cheek of a rim of said bicycle and at least one wheel forming said bicycle and at least one induction piece.

3. Electric assistance device according to claim 2, wherein said and at least one cheek has a thickness greater than 2 millimeters on at least one orthoradial portion of the rim.

4. Electric assistance device according to either of claims 2 or 3, wherein said and at least one cheek has a radial width greater than 15 millimeters on at least one orthoradial portion of the rim.

5. Electric assistance device according to claim 1, wherein the vehicle is a bicycle, and wherein a disc brake disc of said and at least one wheel form said and at least one induction part.

6. Electric assistance device according to claim 1, wherein the vehicle is a bicycle, and wherein: • said and at least one induction part is a plate of generally annular shape with an angular opening of less than or equal to 360°, or • the device comprises a plurality of induction parts, each induction part consisting of a plate of any shape arranged relative to at least one other induction part of the plurality in an assembly of generally annular shape with an angular opening of less than or equal to 360°, fixed to a component of said and at least one wheel selected from a rim, a spoke, a hub of said and at least one wheel.

7. Electric assistance device according to claim 1, wherein the vehicle is a bicycle, and wherein said and at least one induction part is integrated into a tire of said and at least one wheel.

8. An electric assistance device according to any one of claims 1 to 7, wherein the secondary unit further comprises at least one additional ferromagnetic part, associated with said and at least one induction part, the distance separating said and at least one additional part and said and at least one induction part being less than three times the average thickness of the air gap (13), said and at least one additional part preferably being in contact with said and at least one induction part.

9. An electrical assistance device according to any one of claims 1 to 8, wherein the primary unit further comprises: • a housing including: • a front wall intended to face the secondary unit, • a rear wall opposite the front wall, and • at least one side wall between the front and rear walls, said walls being made of an electrically insulating material, • the electrical power supply means (4), • at least one electronic module electrically connected to the electrical power supply means (4), said and at least one electronic module including an electrical power converter for converting a direct current from the electrical power supply means (4) into an alternating current, said and at least one primary magnetic pole (30), said electrical power supply means (4),and said, and at least one electronic module being housed in the casing.

10. An electric assist device according to any one of the preceding claims, wherein the vehicle is a bicycle, and wherein the primary unit is fixed to the frame (10): • at the level of at least one of the rim brake caliper fixings of said bicycle, or • at the level of at least one of the disc brake caliper fixings of said bicycle, said and at least fixing being integrated into the fork or the rear axle.

11. An electric assist device according to any one of the preceding claims, wherein the vehicle is a bicycle, wherein at least a portion of the primary unit has one degree of rotational freedom, approximately about an axis A-A' of wheel displacement, relative to the frame (10), and wherein at least a portion of the face of the secondary unit intended to come into contact with the primary unit at least temporarily on one revolution of The wheel is made of a rubber material or a rubber mixture.

12. An electric assistance device according to any one of the preceding claims, wherein the primary unit comprises at least two magnetic poles, and wherein the supply of said magnetic poles is controlled according to a scalar control of the family of "V / f" controls.

13. Vehicle comprising at least one wheel extending in a plane, characterized in that the vehicle comprises at least one electric assistance device according to any one of claims 1 to 12.