Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K1/00—Details of the magnetic circuit
  • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
  • H02K1/22—Rotating parts of the magnetic circuit
  • H02K1/24—Rotor cores with salient poles ; Variable reluctance rotors
  • H02K1/243—Rotor cores with salient poles ; Variable reluctance rotors of the claw-pole type
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K19/00—Synchronous motors or generators
  • H02K19/02—Synchronous motors
  • H02K19/10—Synchronous motors for multi-phase current
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K19/00—Synchronous motors or generators
  • H02K19/16—Synchronous generators
  • H02K19/26—Synchronous generators characterised by the arrangement of exciting windings

Definitions

• the invention relates to a rotating axial flux electric traction machine for a motor vehicle.
• the invention finds particularly advantageous applications for the propulsion of low-power electric vehicles, in particular between 4kW and 5kW.
• the invention can thus advantageously be implemented in particular with low-power four-wheel electric vehicles ("microcars" in English), two-wheeled motorcycle-type vehicles, or heavy quadricycles.
• the invention also applies to powers of 100 kW to 400 kW at high voltage, for example greater than 400 V.
• Motor control essentially consists of a power adjustment on the armature (usual mode of speed control of a brushed DC motor) supplemented by a continuous flux variation on the inductor. Since such a control is devoid of jerks, handling is often considered disconcerting, even unpleasant, by drivers who enjoy dynamic driving.
• the rotor can be of the homopolar claw type as illustrated in Figure 1.
• the rotor 1 1 described here comprises a single rotating rotor winding 12 regardless of the number of poles p of the rotor.
• the claws, forming the different poles p of the rotor are distributed into two groups of different polarities, a first group and a second group. The two groups are alternated circumferentially.
• the rotor 11 of Figure 1 comprises an annular disk 13 from which the claws extend.
• Each claw of the first group also called first claw 14, has a first axial base 15 which extends from an inner periphery of the disc and a first claw nose extending radially outwards.
• Each claw of the second group also called second claw 18, has a second axial base 19 which extends from an outer periphery of the disc and a second claw nose 20 extending radially towards the inside.
• the rotating rotor winding 12 is mounted axially between the disc 13 and the claw noses 15, 20 and radially between the first bases 15 and the second bases 19.
• the claws are polarized under the effect of the current circulating in the rotor winding 12 so as to form the p poles of the rotor.
• - at least one homopolar rotor, movable in rotation, with p poles comprising: o an annular disk with an axis of symmetry coinciding with the axis of rotation, op/2 upper studs and p/2 lower studs, p being an even integer, the upper studs being radially further away from the axis of rotation than the lower studs, the lower studs and the upper studs being circumferentially alternated at least one concentric rotor winding mounted radially between the upper studs and the lower studs, the upper studs and the lower studs not facing axially the rotor winding, the upper studs and the lower studs being able to be polarized under the effect a rotor current circulating in the rotor winding so as to form p poles of the rotor, and
• At least one stator fixed in rotation, comprising at least one stator coil
• the machine is remarkable in that the rotor winding is fixed in rotation.
• the manufacturing and assembly of the rotor are simplified and less expensive compared to the prior art illustrated.
• the assembly made up of the annular disc and the crampons does not have an undercut zone which complicates its manufacturing, notably with a need for machining.
• the electric machine has substantially identical performances, compared to an identical machine comprising a rotor according to the figure 1.
• the lower studs and the upper studs are circumferentially alternated when a lower stud is angularly framed by two upper studs, without taking into account the radial height.
• a disk within the meaning of the invention designates a circular plate or not.
• a disk can for example have a polygonal outline.
• the rotor winding faces the annular disk axially in one of the two axial directions.
• the studs form the poles of the rotor when the rotor winding is powered.
• Each pole includes a single crampon.
• the lower studs extend from a radially inner periphery of the annular disc.
• the upper studs extend from a radially outer periphery of the annular disc.
• the upper studs and the lower studs form a single piece of the same material with the annular disc. This reduces the number of operations during assembly and simplifies the process.
• the annular disc, the upper studs and the lower studs form a single piece.
• the upper studs and the lower studs are trapezoidal in shape.
• Each upper stud and each lower stud have a cylindrical radially outer surface.
• Each upper stud and each lower stud have a cylindrical radially interior surface.
• the upper studs and the lower studs do not protrude radially from the annular disc.
• all the upper studs and all the lower studs associated with said rotor winding are on the same axial side of the annular disc.
• At least one of the upper studs and the lower studs may have an insert receiving a magnet.
• the magnet increases the field intensity of the rotor.
• the insert may be blind, in particular in the radial direction, in particular in the axial direction, in particular in the axial direction and the axial direction.
• all the upper studs and all the lower studs have a magnet.
• p is between two and thirty-two, in particular between four and sixteen.
• the rotor has a polar pitch equal to 2*TT/P, expressed in radians.
• the lower studs are able to all have the same polarity and the upper studs are able to all have the same polarity opposite to the polarity of the lower studs.
• All lower studs can have the same shape.
• All the bottom cleats can be evenly distributed in the circumferential direction.
• each lower stud has an external angular opening.
• the value of the external angular opening of the lower studs pi can be between 0.5*(polar pitch) and 0.95*(polar pitch).
• each lower stud has an interior angular opening.
• the value of the interior angular opening of the lower studs P2 can be between 0.5*(polar pitch) and 0.95*(polar pitch).
• the exterior angular opening may be greater than or equal to the interior angular opening.
• the lower studs can expand radially outwards.
• All upper crampons can have the same shape. All upper studs can be evenly distributed in the circumferential direction.
• each upper stud has an external angular opening.
• the value of the external angular opening of the upper crampons P3 can be between 0.5*(polar pitch) and 0.95*(polar pitch).
• each upper stud has an interior angular opening.
• the value of the interior angular opening of the upper studs P4 can be between 0.5*(polar pitch) and 0.95*(polar pitch).
• the interior angular opening may be greater than or equal to the upper angular opening.
• the upper studs can expand radially inward.
• the annular disk can be hollow.
• the annular disk is mounted on a rotor shaft.
• the annular disc is for example fitted or shrink-fitted.
• the annular disk has an exterior radius.
• the value of the exterior radius Rext can be between 10 cm and 40 cm, preferably between 10 cm and 20 cm, in particular 15 cm.
• the annular disk has an interior radius.
• the value of the interior radius Rint can be between 0.1 *Rext and 0.75*Rext, in particular between 0.4*Rext and 0.60*Rext, for example 0.5*Rext.
• the radially exterior surfaces of the upper studs are contiguous with the radially exterior surface of the annular disc.
• the radially interior surfaces of the lower studs are contiguous with the radially interior surface of the annular disc.
• the rotor has an axial rotor dimension, the value Lz of which can be between 2cm and 10cm, in particular between 3cm and 5cm, for example 3.6cm.
• the annular disc has an axial thickness.
• the value of the axial thickness of the annular disc ez1 can be between 0.25*Lz and 0.4*Lz.
• each upper stud and each lower stud has an axial dimension.
• This axial dimension can be identical for each of the upper studs and each of the lower studs.
• the value of this axial dimension ez2 can be between 0.5*Lz and 0.75*Lz.
• the electric machine has a greater radial air gap between the upper studs and the rotor winding of between 0.1 mm and 1 mm.
• the electric machine has a lower radial air gap between the lower studs and the rotor winding of between 0.1 mm and 1 mm.
• the electric machine has an axial air gap between the rotor winding and the annular disk.
• the radial air gap can be between 0.1 mm and 1 mm.
• the rotor winding is mounted on the stator.
• the fixed parts of the machine are thus shared, which avoids the need for a fixed part dedicated to the rotor winding.
• the electric machine comprises a single rotor winding.
• the electric machine can comprise a plurality of rotor windings powered in parallel.
• the electric machine comprises a casing.
• the rotor winding is carried by a rotor disk, the rotor disk and the stator are fixed on the casing.
• the rotor disk is a part independent of the stator.
• the rotor disk may be non-magnetic.
• the stator comprises a printed circuit board “PCB”.
• the printed circuit board may include at least one PCB layer including the stator coil.
• the printed circuit board "PCB” may comprise a plurality of PCB layers.
• each PCB layer comprising a plurality of stator coils.
• These stator coils can be coplanar and spaced angularly and symmetrically with respect to each other.
• each stator coil is continuous and concentric in a single plane from an outermost stator coil portion to an innermost concentric stator coil portion.
• stator coils in adjacent PCB layers are circumferentially aligned with each other relative to the axis to define symmetrical stacks of stator coils in an axial direction.
• each stator coil includes a first terminal on the outer edge of the coil, a second terminal in the center of the stator coil.
• each stator coil can be connected directly to an adjacent stator coil on the same PCB layer.
• Each stator coil can be connected directly to a corresponding stator coil on another PCB layer.
• each stator coil has only two terminals, each coil being continuous and uninterrupted between its two terminals alone.
• the rotor winding is fixed on the printed circuit board, for example overmolded.
• the stator comprising a plurality of teeth, the stator coil being wound around said teeth.
• the stator comprises a plurality of stator coils, each being wound on one of said teeth.
• the rotor winding is traversed by the direct rotor current, and in that the at least one stator coil is traversed by a polyphase stator current system.
• the rotor current does not change sign and is mainly used to set the flux level. Note that the rotor winding is not traversed by a polyphase current system in normal operation.
• the rotor winding is electrically connected to a control device.
• the control device may include a plurality of controllable switches in order to continuously vary the current in the winding.
• the switches may be Mosfets and/or diodes.
• the controllable switches can be arranged in an H-bridge.
• each rotor is framed axially by two stators.
• the rotor may include p/2 upper studs and p/2 lower studs on each of the two axial sides of the annular disc.
• each rotor can be associated with two rotor windings, each rotor winding being associated with an axial side of the annular disk.
• each stator is framed axially by two rotors.
• the two rotors can be associated with the same stator.
• the electric machine can have a nominal mechanical power of between 4 kW and 35 kW, being for example 4 kW, 8 kW, 15 kW, 25 kW or 35 kW, or the electric machine can have a nominal mechanical power of between 40kW and 400kW, being for example 40kW, 80 kW, 100 kW, 150 kW, 180 kW, 200 kW, 300 kW or 400 kW.
• This rotating electric machine can be electrically powered from an electrical energy storage unit via an inverter/rectifier, this inverter/rectifier allowing, depending on whether the electric machine operates as a motor or generator, to charge an on-board network of the vehicle or to be electrically powered from this network.
• the nominal voltage of the electrical energy storage unit may be 12 V, 48 V or have another value, for example another value greater than 300 V.
• the invention also relates to a motor vehicle characterized in that it comprises a rotating electric machine as previously defined to propel said vehicle.
• the electric traction machine is installed on a rear axle between a wheel and a differential of said motor vehicle.
• the electric machine could be installed directly in the wheel of the vehicle in a “wheel-motor” type assembly.
• the motor vehicle can be a purely electric traction vehicle.
• the vehicle can be a hybrid traction vehicle. Both thermal and electric.
• the motor vehicle can be an electric utility vehicle or a light truck.
• the electric machine according to the invention of the axial type, makes it possible to obtain a higher specific power and a higher continuous power than the electric machines according to the prior art.
• This electric machine is suitable for the driving profiles of utility vehicles carrying loads and requiring continuous electrical power.
• FIG. 1 is a perspective view of an example of a rotor according to the prior art.
• FIG. 2 is a schematic view of an example of a motor vehicle according to the present invention.
• FIG. 3 is an exploded perspective view of an example of an electrical machine according to the invention.
• FIG. 4 is a perspective view of a rotor of the electric machine of Figure 3.
• FIG. 5 is a front view of the rotor and the rotor winding of Figure 3.
• FIG. 6 is a front view of an example of a stator of the electric machine according to the invention.
• the motor vehicle is an electric vehicle EV comprising wheels 3 and the electric machine 10.
• the electric machine is configured to drive at least indirectly at least one of the wheels 3.
• the vehicle comprises a high power battery voltage B, preferably a rechargeable battery, to provide electrical energy to the machine.
• Battery B is for example a high voltage supply, in particular greater than 60V.
• the battery can also be a low voltage battery, in particular 48V.
• the electric machine 10 makes it possible to move the vehicle EV alone and is installed on a rear axle 2 between a rear wheel 3 and a differential.
• the electric machine 10 could be installed on the front axle, not shown.
• the electric machine 10 could be installed in at least one wheel 3.
• an electric machine 10 is used in each rear wheel 3.
• the electric machine 10 comprises at least one rotor, at least one rotor winding and at least one stator. These will be described in more detail in connection with the following figures.
• the stator is powered via an inverter/rectifier I configured to convert a direct voltage (DC) from the battery B into an alternating voltage (AC) in order to control the electrical machine 10.
• the stator is traversed by a polyphase stator current system Is, in particular three-phase.
• the rotor winding is also powered by the battery B by a continuous rotor current Ir.
• the rotor winding is electrically connected to battery B.
• the rotor winding is capable of continuously generating a rotor current from zero to a maximum value in order to vary the rotor flux
• FIG. 3 now describes in detail an example of an axial flux machine 10 according to the invention which can be fitted to the vehicle described in Figure 2.
• the electrical machine is axial flux and rotates around an axis X of rotation.
• the rotor 1 1 is homopolar, is movable in rotation and has p poles.
• the rotor 11 comprises an annular disk 15 with an axis of symmetry coinciding with the axis X.
• the rotor 11 also includes p/2 upper studs 16 and p/2 lower studs 17.
• the upper studs 16 are radially further away from the axis X than the lower studs 17.
• the lower studs 17 and the upper studs 16 are circumferentially alternate. Each lower stud 17 is angularly framed by two upper studs 16, without taking into account the radial height.
• P is an even integer.
• P is between two and thirty-two. Sixteen here.
• the rotor 11 has a polar pitch equal to 2*Pi /p or for TT/8 radians for a polarity of 8, or .22.5 degrees.
• the electric machine 10 comprises at least one concentric rotor winding 20 mounted radially between the upper studs 16 and the lower studs 17.
• the upper studs 16 and the lower studs 17 do not face axially the winding rotor 20.
• the upper studs 16 and the lower studs 17 are polarized under the effect of the rotor current Ir circulating in the rotor winding 20 so as to form the sixteen poles of the rotor 11.
• the lower studs 17 all have the same polarity and the upper studs 16 all have the same polarity opposite to the polarity of the lower studs 17.
• Each of the sixteen poles of the electric machine 10 comprises a single stud among the upper studs 16 and the lower studs 17.
• the rotor winding 20 is fixed in rotation.
• the rotor winding 20 is carried by a rotor disk 21 itself fixed in rotation which is an independent part of the stator.
• the rotor winding is mounted on the stator. There is no rotor disk dedicated to fixing the rotor winding.
• the rotor winding 20 is unique.
• the rotor winding 20 faces axially the annular disc 15 in one of the two axial directions, that is to say along the axis X. All the upper studs 16 and all the lower studs 17 associated with the winding rotor are on the same axial side of the annular disk 15.
• the lower studs 17 extend from a radially inner periphery 22 of the annular disc 15 and the upper studs 16 extend from a radially outer periphery 23 of the annular disc 15.
• the upper studs 16 and the lower studs 17 do not protrude radially from the annular disc.
• the upper studs 16 and the lower studs 17 come from the same material as the annular disc 15.
• the annular disc 15, the upper studs 16 and the lower studs 17 thus form a single piece.
• the upper studs 16 and the lower studs 17 are all trapezoidal in shape.
• Each upper stud 16 and each lower stud 17 have a radially outer cylindrical surface and have a radially inner cylindrical surface.
• the radially outer surfaces of the upper studs 16 are contiguous with the radially outer surface of the annular disc 15 and the radially inner surfaces of the lower studs 17 are contiguous with the radially inner surface of the annular disc 15.
• each lower stud 17 has the same shape and are uniformly distributed in the circumferential direction.
• Each lower stud 17 has an exterior angular opening pi whose value is between 0.5*(polar pitch) and 0.95*(polar pitch) and an interior angular opening P2 whose value is between 0.5*( not polar) and 0.95*(not polar).
• pi and P2 are equal.
• all the upper studs 16 have the same shape and are uniformly distributed in the circumferential direction.
• Each upper stud 16 has an exterior angular opening P3 whose value is between 0.5* (polar pitch) and 0.95* (polar pitch) and an interior angular opening P4 whose value is between 0.5*(polar pitch) and 0.95*(polar pitch).
• P4 is larger than P2.
• the upper studs widen radially inwards.
• the annular disk 15 is hollow.
• the annular disk is mounted on a rotor shaft, not shown, for example fitted or shrink-fitted.
• the annular disk has an exterior radius Rext whose value is between 10 cm and 40cm, preferably between 10cm and 20cm, in particular 15cm and an interior radius Rint whose value is between 0.1 *Rext and 0.75*Rext, in particular between 0.4*Rext and 0.60*Rext, for example 0.5*Rext.
• the rotor 11 has an axial rotor dimension, the value Lz of which can be between 2cm and 10cm, in particular between 3cm and 5cm, for example 3.6cm.
• the annular disc 15 also has an axial thickness ez1 whose value is between 0.25*Lz and 0.4*Lz.
• each upper stud 16 and each lower stud 17 has an identical axial dimension ez2 whose value is between 0.5*Lz and 0.75*Lz.
• the electrical machine 10 has an upper radial air gap 25 between the upper studs 16 and the rotor winding 20 of between 0.1 mm and 1 mm.
• the electrical machine 10 has a lower radial air gap 26 between the lower studs 17 and the rotor winding 20 of between 0.1 mm and 1 mm.
• the electrical machine has an axial air gap of between 0.1 mm and 1 mm between the rotor winding and the annular disk.
• stator 12 In the example considered, the rotor disk 21 and the stator can be fixed on a casing of the electrical machine 10.
• An example of stator 12 is described with reference to Figure 6.
• the stator 12 is fixed in rotation and comprises a plurality of stator coils 30 and a printed circuit board “PCB” 31.
• the printed circuit board may include a plurality of PCB layers.
• Each PCB layer comprises a plurality of coplanar stator coils 30, spaced angularly and symmetrically with respect to each other.
• each stator coil 30 is continuous and concentric in a single plane from an outermost stator coil portion to an innermost concentric stator coil portion.
• stator coils in adjacent PCB layers are circumferentially aligned with each other relative to the axis to define symmetrical stacks of stator coils in an axial direction.
• each stator coil 30 is connected directly to an adjacent stator coil on the same PCB layer.
• the rotor winding 20 can be mounted on the stator 12.
• the rotor winding can be overmolded or soldered onto the printed circuit board 31.
• the electric machine 10 does not have a rotor disk. .
• the stator comprises a plurality of coils, each being wound on one of said teeth.
• the machine can comprise a single stator 12 surrounded by two rotors 11.
• the electrical machine 10 comprises a plurality of rotors 11, each rotor 11 being framed axially by two stators 12.
• the rotors 11 can then comprise the upper studs 16 and the lower studs 17 on each of the two axial sides of the annular disk 15.
• Each rotor 11 can be associated with two rotor windings 20, each rotor winding being associated with an axial side of the annular disk.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Iron Core Of Rotating Electric Machines (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=83690474

Family Applications (1)

Country Status (4)

Families Citing this family (2)

Family Cites Families (7)

• 2022
  • 2022-08-04 FR FR2208110A patent/FR3138741B1/fr active Active
• 2023
  • 2023-07-21 EP EP23741741.5A patent/EP4566151A1/de active Pending
  • 2023-07-21 WO PCT/EP2023/070335 patent/WO2024028133A1/fr not_active Ceased
  • 2023-07-21 CN CN202380064355.4A patent/CN119856372A/zh active Pending

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