Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K15/00—Processes or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
  • H02K15/02—Processes or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies
  • H02K15/021—Magnetic cores
  • H02K15/023—Cage rotors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64D—EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
  • B64D27/00—Arrangement or mounting of power plants in aircraft; Aircraft characterised by the type or position of power plants
  • B64D27/02—Aircraft characterised by the type or position of power plants
  • B64D27/30—Aircraft characterised by electric power plants
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K17/00—Asynchronous induction motors; Asynchronous induction generators
  • H02K17/02—Asynchronous induction motors
  • H02K17/16—Asynchronous induction motors having rotors with internally short-circuited windings, e.g. cage rotors
  • H02K17/168—Asynchronous induction motors having rotors with internally short-circuited windings, e.g. cage rotors having single-cage rotors
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K17/00—Asynchronous induction motors; Asynchronous induction generators
  • H02K17/02—Asynchronous induction motors
  • H02K17/16—Asynchronous induction motors having rotors with internally short-circuited windings, e.g. cage rotors
  • H02K17/18—Asynchronous induction motors having rotors with internally short-circuited windings, e.g. cage rotors having double-cage or multiple-cage rotors
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K1/00—Details of the magnetic circuit
  • H02K1/02—Details of the magnetic circuit characterised by the magnetic material
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K15/00—Processes or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
  • H02K15/02—Processes or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies

Definitions

• the present invention relates to the field of electric motors and more particularly relates to the field of electric motor rotors for aeronautical applications.
• the preferred ways are to reduce the mass of the electric motors of generation and/or starting or electric propulsion if we are in the field of "VTOL" (Vertical Take Off and Landing, which means vertical take-off and landing)" or “STOL” (Short Take Off and Landing, which means take-off and landing short).
• VTOL Vertical Take Off and Landing, which means vertical take-off and landing
• STOL Short Take Off and Landing, which means take-off and landing short.
• the mass of these systems can reach several tens of kilograms for powers that can go beyond a hundred kilowatts. Current limitations on electric machines hardly exceed a power/mass ratio of 3.5 kW/kg.
• the first performance limitation is essentially due to the electromagnetic circuit itself, which is governed by the quality of the ferromagnetic materials used or even the quality of the magnets (remanent induction Br) when these machines include them.
• the second limitation is the mechanical limitation in the rotation speed of the machines. This speed limitation depends on the nature of the electrical machine. We distinguish three main families of electric machines (ie electric motors): direct current machines, synchronous machines and asynchronous machines.
• machines (d) are rotor mounted permanent magnet synchronous machines and machines (e) are solid rotor induction asynchronous machines.
• the machine can contain high-energy debris originating from rotating parts of the rotor of the machine (i.e. the machine must continue to operate despite the breakage and the presence within it of parts of the rotor). Moreover, in many other cases of failure, it is necessary that the electrical machine continues to operate.
• DC machines are the machines most used in the aeronautical industry. Their main advantage is to operate on direct current networks without the mandatory use of power electronics. Their main disadvantage is to include brushes energizing the rotor which causes a premature wear of the latter and imposes limitations in terms of rotation speed (max speed ⁇ 20,000 rpm).
• Wound-rotor synchronous machines are machines which have the main advantage of being very easily controllable in terms of torque and speed. Indeed, it is possible to manage the flux of the machine very easily by injecting a direct current into the inductor of the machine (rotor part) using conductive rings linking the stator and the rotor. These machines have a similar drawback to DC machines which is a maximum rotor speed relative to the stator of around 25,000 rpm. This speed limitation is due to the presence of conductive rings rubbing on the rotor.
• 3-stage synchronous machine these machines are very widely used in the aeronautical world as current generators because they have the advantage of being easily controllable and self-excitable without brushes or ring thanks to the rotation of magnets in front of the rotor winding of the machine, the alternating current thus created is then rectified by rotating diodes going as far as the field winding of the machine.
• the disadvantages of these machines are their relatively large masses due to the fact that they comprise several conversion stages and also a limitation of the rotation speed ( ⁇ 25,000 rpm) which comes to weaken the rotating diodes when the speed becomes too high. important.
• permanent magnet machines are one of the most efficient categories of machines in terms of torque density, it is moreover for their excellent performance that these machines emerge in aeronautical electrical systems.
• Their advantage which is also their main drawback, is that these machines have magnets in the rotor, which has the main advantage that these machines do not have brushes and are self-excited due to the rotation of the magnets.
• the short-circuit is self-sustaining due to the rotation of the magnets which generates this short-circuit. It is therefore necessary to be able to stop the rotation of the rotor so that the fault does not propagate.
• Another disadvantage of this machine is that, when very high rotational speeds (above 30,000 rpm) must be reached, the machine must include surface magnets whose thickness becomes non-negligible compared to the magnetic air gap which generates a significant increase in magnetic losses.
• the synchronous reluctance machine is a machine with strong electromagnetic performance
• another advantage is that the rotor is magnetically passive in nature, so in the event of a problem with the stator windings, the machine is de-energized by de-energizing the stator.
• the main drawback of this machine for use in an aeronautical environment is that this machine imposes a very small air gap ( ⁇ 0.5 mm) hence an increased complexity for the integration of this machine in a fairly severe vibratory environment.
• the squirrel cage asynchronous machine is a machine with lower electromagnetic performance compared to synchronous machines due to the fact that the induction of rotor currents generated by the stator currents tend to heat the rotor .
• the concept of sliding is also to be considered in this machine.
• the slip is the difference between the pulsation of the currents created in the rotor and the pulsation of the stator currents. This slip is a fundamental notion because the greater the slip (and tends towards 1), the more torque the machine provides.
• the fundamental problem of this principle is that the Joule effect created in the rotor part of the machine is directly proportional to the slip.
• asynchronous machine with massive rotor To solve this problem of electromagnetic performance limitation, new topologies of asynchronous machines have recently appeared for ten years called asynchronous machine with massive rotor.
• the notion of a massive rotor comes from the fact that the rotor, which can be multi-material, is very compact and resistant to much greater mechanical stress than squirrel-cage asynchronous machines.
• the objective of the present invention is to propose a new asynchronous machine rotor topology exhibiting better performance at high speed (i.e. speeds greater than 30,000 rpm).
• the invention relates to an aircraft electric motor rotor comprising a shaft made of a first material and a conductor assembly made of a second material different from the first material, in which the shaft has a shoulder portion having at least one longitudinal notch and the conductive assembly is a one-piece structure comprising at least one conductive bar intended to be positioned in the at least one notch and comprising a skin intended to be fixed on the shoulder portion.
• the rotor may have an interpenetration layer of the first material and of the second material, the interpenetration layer comprising an alloy of the first material and of the second material.
• the conductor assembly may include two rings, a first ring being attached to the rotor at a first end region of the shoulder portion and a second ring being attached to the rotor at a second end region of the shoulder portion .
• the rotor may comprise a plurality of notches tangentially distributed and/or radially superimposed in the shoulder.
• the plurality of notches may comprise two contiguous radially superimposed notches in the shoulder, an opening connecting said two contiguous notches.
• the first material may contain at least iron and carbon.
• the second material may contain at least one of the metals chosen from among copper, aluminum or silver.
• the invention relates to a method for manufacturing a rotor according to the first aspect comprising at least one of the steps of:
• the step of inserting the shaft and an element intended to form the conductor assembly into a protective tubular casing comprises a phase of positioning, around the shaft, a powder intended to form the assembly driver.
• the step of heating and pressurizing the assembly can be carried out in a dedicated enclosure and in a neutral atmosphere.
• the heat treatment step may include quenching selected from natural or forced convection gas quenching, water quenching or oil quenching.
• the first material may contain at least iron and carbon, and the heat treatment step may be carried out until the first material becomes martensitic.
• the method may include a prior step of machining the shaft.
• the step of machining the shaft may include at least one phase of machining at least one notch.
• Figure 1 is a graph representing the maximum power of different electric machines as a function of rotational speed.
• Figure 2 is a schematic representation, in perspective, of a rotor according to the invention.
• Figure 3 is a schematic representation, in perspective, and in partial section of a rotor according to the invention.
• Figure 4 is a schematic representation, in perspective, of a tree according to the invention.
• Figure 5 is a schematic representation, from the front, of a shaft according to the invention.
• Figure 6 is a schematic representation of two contiguous radially superimposed notches.
• Figure 7 is a schematic representation of the positioning of a shaft in an envelope according to the invention.
• FIG. 8 is a sectional view of the representation of Figure 7.
• FIG. 9 is a representation of an envelope containing a shaft and a powder making it possible to form a conductive assembly.
• Figure 10 is a representation of a tree and a conductor assembly extracted from the envelope.
• Figure 11 is a representation of a rotor obtained by a method according to the invention.
• Figure 12 is a representation of a diagram of change in microstructure of a steel, in a time interval, as a function of temperature.
• Figure 13 is a comparative representation of the magnetic hysteresis of two samples of a material having received two different tempers.
• the invention proposes an aircraft electric motor rotor 1 comprising a shaft 2 made of a first material and a conductor assembly 4 made of a second material different from the first material.
• conductor it is understood an electrically conductive element, that is to say capable of allowing the circulation of electricity within it.
• Shaft 2 is a one-piece revolution part.
• an orthogonal reference is defined linked to the shaft 2.
• the longitudinal direction corresponds to the axis of revolution of the shaft 2.
• the radial direction is a direction perpendicular to the longitudinal direction, s extending from the longitudinal direction towards an outer cylindrical surface of the shaft 2.
• the tangential direction is a direction perpendicular to the longitudinal direction and to the radial direction.
• the tangential direction is tangent to an outer cylindrical surface of shaft 2.
• the shaft 2 has in particular a shoulder portion 6. It is specified that by shoulder portion is meant a portion comprised between two circular crowns normal to the axis of revolution of the shaft 2 and resulting from a sudden change in diameter.
• the shoulder portion 6 has two end regions 8 (ie each being a circular crown). Each end region 8 of the shoulder portion 6 has a groove intended to accommodate a ring 12.
• the shoulder portion 6 comprises a plurality of longitudinal notches 25.
• Each notch 25 is in the form of a groove (or groove) in the shoulder 6.
• the notches 25 are recessed sculptures in the surface of the shoulder 6.
• Each notch 25 has an opening emerging in the surface of the shoulder 6.
• FIG. 6 shows schematically in Figure 6, several notches 25 can be radially superimposed in the shoulder 6.
• radially superimposed it is understood that - for example - two notches 25 can follow one another in the same radial direction.
• two adjoining notches 25 radially superimposed have an opening 30 connecting said two adjoining notches.
• two radially superimposed and contiguous notches 25 communicate through an opening 30 connecting them.
• the so-called double notch 25 architecture (i.e. two radially superimposed notches 25) makes it possible to optimize the profile of the torque that can be delivered by an electric motor comprising a rotor 1 .
• the notches 25 may be tangentially distributed in the shoulder 6. Even more preferably, the notches 25 are evenly distributed.
• the shaft 2 may have a longitudinal bore.
• the bore may include a splined portion.
• the shaft 2 is made of a magnetic material comprising an alloy of iron and carbon.
• the alloy of the shaft 2 is a steel mainly comprising iron and carbon.
• the alloy is a martensitic steel comprising more than 1% carbon.
• This structure of the steel allows the shaft 2 to channel the magnetic field lines coming from the windings to the stator (when the rotor is operating in an electric motor) so that the conductive element 4 receives as much magnetic field as possible.
• the shaft alloy can be chosen from 17-4PH, ⁇ ISI 416 (EN-1 -4005), ⁇ ISI 431 (EN-1 -4057), ⁇ ISI 1020 (XC18), ⁇ ISI 1045 (XC48).
• this alloy can include other components in addition to iron and carbon, so for example to make stainless steel (example: Chrome Cr, Nickel Ni).
• the geometry of the shaft 2 can for example be obtained by turning and the martensitic structure is obtained by heat treatment.
• the conductor assembly 4 is a one-piece structure - preferably made of copper - positioned on the shoulder region 6.
• the conductor assembly 4 comprises a plurality of conductor bars 28 and a skin 29.
• each conductive bar 28 is positioned in a notch 25. It is remarkable that the conductive bars 28 have a geometry complementary to the notches 25. In other words, each conductive bar 28 fills the whole ( or almost all) of a notch 25.
• all the notches 25 are filled with a conductive bar 28 and all of the shoulder 6 and the conductive bars 28 are entirely covered by the skin 29.
• the skin 29 can advantageously have a thickness of the order of 1 to 5 millimeters.
• the conductor assembly 4 may comprise two rings 12 which are each intended to be positioned in a groove of an end region 8.
• each ring 12 is integral with the conductor assembly 4.
• each ring 12 is made in one piece with the conductor assembly 4.
• the rings 12 have a short-circuit function and are used to loop back the induced currents to the rotor.
• the conductor assembly 4 is made of copper. Copper is chosen for its excellent conductivity. According to another embodiment, the conductor assembly 4 could for example be made of silver or aluminum. It is specified that the material such as copper or silver, constituting the conductor assembly 4 is not necessarily a pure material and may be an alloy based on copper, based on aluminum or based on money. For example, the copper alloy may comprise addition elements such as chromium and zirconium or cobalt or even Beryllium.
• This welding is carried out so that the rotor 1 has a layer of interpenetration due to the existence of a diffusion of material between the conductor assembly 4 and the shaft 2, at the level of the portion of shoulders 6 and 8 and notches 25.
• the rotor has a layer of interpenetration of the material of the shaft 2 and the material of the conductor assembly 4.
• interpenetration is meant a layer of alloy of the material of the shaft 2 (first material) and of the material of the conductor assembly 4 (second material).
• this interpenetration is carried out without the addition of a third material.
• the welding of conductor assembly 4 and shaft 2 includes only conductor assembly 4 and shaft 2 and does not involve any additional material.
• the interpenetration layer is the result of diffusion welding of the conductor assembly 4 and of the shaft 2.
• This arrangement very advantageously makes it possible to have excellent mechanical strength over the entire surface of the shoulder portion 6, the end regions 8, and the notches 25, which allows the rotor 1 to withstand rotational speeds greater than 50,000 rpm in the present setup.
• the invention relates to a method of manufacturing a rotor 1 as described previously.
• the method comprises the steps of:
• diffusion welding is a technique allowing the assembly of elements in solid phase, that is to say without melting thanks to the simultaneous application of a temperature and a high pressure.
• the step of inserting the shaft 2 and an element intended to form the conductor assembly 4 into a protective tubular casing 30 comprises a positioning phase, around the shaft, of a powder intended to form the conductor assembly 4.
• This metallic powder has a particle size equivalent to that required for a sintering process, for example from ten to a few tens of ⁇ m in average diameter, and a distribution which is also controlled.
• the powder agglomerates and fuses, similar to the sintering process, in the casing 30 to form the conductor assembly 4.
• the method may include a prior step of machining the shaft 2. More specifically, this prior step may include at least one phase of machining the notches 25.
• the diffusion welding phase can be carried out in an enclosure using a hot isostatic compression (CIC) method.
• CIC hot isostatic compression
• diffusion welding is a technique allowing the assembly of elements in solid phase, that is to say without melting thanks to the simultaneous application of a temperature and a high pressure.
• a hot isostatic pressing (CIC) method may include a step of degreasing and stripping the surfaces of the elements to be assembled, a step of bringing the degreased and stripped surfaces of the elements to be assembled into direct contact, and a step of assembly by diffusion welding of the surfaces of the elements in contact.
• the step of degreasing and pickling the surfaces of the elements to be assembled can consist of conventional treatments for degreasing and pickling metal surfaces.
• the purpose of this step is to obtain clean, degreased and oxidation-free surfaces.
• the degreasing of these surfaces can for example be carried out using a solvent or a conventional detergent for degreasing metals.
• Pickling can be a chemical or mechanical pickling, it can for example be carried out by means of an acid or basic solution, or by rectification or polishing.
• the stripping technique can be chemical stripping followed by rinsing with water during which the surface of the materials is rubbed with the aid of an abrasive pad based, for example, on fibers of alumina. This treatment can be repeated several times, the last rinsing being able to be carried out with demineralised water.
• the degreasing solvent can be an organic solvent, for example of the ketone, ether, alcohol, alkane or chlorinated alkene type such as trichloroethylene, or a mixture of these. here, etc.
• a preferred solvent is a mixture of equal proportions of ethyl alcohol, ether and acetone.
• Another preferred solvent is trichlorethylene.
• Chemical pickling can be carried out with an acid solution, for example a 10% hydrofluoric acid bath or a mixture comprising 1 to 5% hydrofluoric acid with 30 to 40% nitric acid.
• the pickling time can be for example from 10 seconds to 5 minutes, for example from 20 to 30 seconds, at a temperature of 15°C, for example 20°C.
• the pickled surfaces can then be rinsed in one or more successive baths, for example of demineralised water.
• the next step is a step of bringing the degreased and pickled surfaces of the elements into direct contact.
• This bringing into contact corresponds to placing or positioning the elements to be assembled surface against surface, according to a desired stack.
• this contacting is carried out within a period of less than one hour following the step of degreasing and stripping the surfaces to be assembled, so as to limit the risks of oxidation, except in the case where special precautions have been taken.
• these precautions possibly consisting, for example, in keeping the elements in a clean and non-oxidizing atmosphere such as nitrogen by means of bagging them in sealed bags.
• the step which follows the bringing into contact of the surfaces of the elements to be assembled is a step of assembly by diffusion welding of the surfaces brought into direct contact. Diffusion welding can be carried out, for example, by isostatic compression or by hot uniaxial pressing, for example, by conventional techniques known to those skilled in the art.
• the materials brought into contact can be introduced into an envelope which makes it possible to isolate the elements to be assembled from the atmosphere and to evacuate the air from the envelope for the assembly of the elements by diffusion welding therein.
• the casing 30 can be made of any impermeable material, strong enough to withstand an at least partial vacuum therein, and to withstand the high temperatures and pressures necessary to assemble the elements.
• the casing can be a metal casing, for example made of stainless steel, mild steel or titanium and its alloys. It can for example be formed from a sheet having a thickness for example of 1 to 20 mm approximately, for example of 1 to 10 mm approximately.
• the envelope can match the external shape of the elements to be assembled.
• the martensitic stainless steel element (the shaft 2) can close the casing 30 by playing the role of cover of the casing 30, the shaft 2 then being able to be welded to the casing 30
• this casing 30 can be produced by cutting, optionally bending and welding a metal sheet or by any method known to those skilled in the art.
• the envelope 30 is then degassed so as to create a vacuum therein.
• the degassing can be carried out by means of a vacuum pump and heating of the elements to be assembled/envelope assembly.
• An example of degassing may consist in evacuating the air from the casing 30 at ambient temperature until a residual vacuum of less than or equal to 10 Pa is obtained, then in heating the assembly to a moderate temperature, for example lower at 300°C for a few hours, for example 5 hours, while continuing to evacuate.
• the casing 30 is made completely sealed by closing the opening which served for its evacuation, the closing being carried out for example using TIG welding.
• the elements brought into contact in the degassed envelope can then be assembled by diffusion welding.
• the assembly can be carried out in a hot isostatic compression chamber.
• the heating step includes a phase of pressurizing the assembly 32.
• a heating enclosure i.e. an oven
• the pressure inside a heating enclosure can be brought to a value between 1000 and 2000 bars (preferably the pressure can be around 1500 bars).
• the heating is carried out in a so-called neutral atmosphere.
• the heating chamber of the oven used is saturated with an inert gas (i.e. a rare gas according to the periodic table of the elements).
• the neutral gas used may be argon.
• the atmosphere of the heating enclosure can be saturated with nitrogen.
• One of the objectives of the saturation of the heating enclosure with argon or nitrogen is to drive out the oxygen to avoid a potential oxidation reaction.
• the heating step is carried out by bringing the assembly 32 to a temperature allowing welding by diffusion but lower than a temperature of liquefaction of the copper (and consequently of the steel).
• the maximum heating temperature can be between 900° C. and 1040° C. to carry out the solution treatment of the steel.
• the heat treatment step may comprise quenching selected from open air quenching, water quenching or oil quenching.
• the hardening can be homogeneous for the whole of the assembly 32 or can be monitored via in-situ measurements.
• the quenching heat treatment step is determined so that the steel of the shaft 2 becomes martensitic. More specifically, the heat treatment step removes any presence of residual austenite in the steel of shaft 2.
• quenching must correspond to a cooling rate greater than the critical rate to create the martensitic phase, i.e. several tens of degrees/second (°/s).
• the objective of quenching is to reach at least the zone indicated V2 in figure 12 and at best the zone indicated V1.
• the quenching step is very advantageous to improve the electromagnetic properties as shown in Figure 13 which shows that the cooling rate has a direct impact on the electromagnetic properties of the material.
• the magnetic hysteresis H1 corresponds to a material quenched in water
• the magnetic hysteresis H2 corresponds to quenching in air.
• the cryogenic bath can be at a temperature below -20° C.
• the assembly 32 is immersed in the cryogenic bath for a period that can be between 10 minutes and 60 minutes.
• the tempering step makes it possible to recover the characteristics sought for the copper constituting the conductor assembly 4 (mechanical resistance, electrical conductivity, etc.), and makes it possible to soften the martensitic steel to increase its ductility while preserving its electromagnetic properties, which makes it possible to optimize the overall performance of the rotor 1.
• tempering step is a known step in the field of metallurgy. In a usual way, income can also be called “ageing”.
• tempering is carried out by bringing assembly 32 to a plateau temperature of between 450° C. and 650° C., over a period of between 1 hour and 4 hours.
• This optimized treatment makes it possible to guarantee for the copper alloy a conductivity equal to or greater than 90% of the conductivity of pure copper (%I ⁇ CS) and ensures that the desired mechanical properties are maintained.
• Separation of casing 30 and rotor 1 is achieved by machining casing 30 to retain only rotor 1 .
• the envelope 30 is extracted by machining, typically by turning.
• the rotor 1 obtained then has rough dimensions, as shown in figure 10.
• the rotor 1, and more particularly its conductor assembly 4 is machined to have the final dimensions and geometries.
• the rotor 1 obtained has the geometric characteristics necessary for its use, and also has structural and electromagnetic characteristics guaranteeing its resistance when used at speeds of rotation greater than 50,000 rpm.
• the bonding zone by interdiffusion on the part obtained according to the process typically has a thickness of a few tens of ⁇ m.
• the rotor 1 having a structure of the monolithic type can easily be statically and dynamically balanced (by localized removal of material), which makes it possible to guarantee the lowest possible vibration level compatible with a high speed of rotation of the rotor 1 .

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Aviation & Aerospace Engineering (AREA)
• Manufacture Of Motors, Generators (AREA)
• Iron Core Of Rotating Electric Machines (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=82483201

Family Applications (1)

Country Status (5)

Families Citing this family (2)

Citations (3)

Family Cites Families (9)

• 2021
  • 2021-09-14 FR FR2109613A patent/FR3127086B1/fr active Active
• 2022
  • 2022-09-14 US US18/690,534 patent/US20240413722A1/en active Pending
  • 2022-09-14 EP EP22789632.1A patent/EP4402783A1/de active Pending
  • 2022-09-14 WO PCT/FR2022/051730 patent/WO2023041873A1/fr not_active Ceased
  • 2022-09-14 CN CN202280058558.8A patent/CN117882280A/zh active Pending

Patent Citations (3)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events