Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K15/00—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
  • H02K15/02—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies
  • H02K15/024—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines of stator or rotor bodies with slots
• • 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
  • H02K1/12—Stationary parts of the magnetic circuit
  • H02K1/20—Stationary parts of the magnetic circuit with channels or ducts for flow of cooling medium
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K2201/00—Specific aspects not provided for in the other groups of this subclass relating to the magnetic circuits
  • H02K2201/06—Magnetic cores, or permanent magnets characterised by their skew

Definitions

• the present invention relates to rotating electrical machines and more particularly to the stators of such machines.
• the invention relates more particularly to the stator mass of the stator and the corresponding rotating electrical machine. It also relates to the method of manufacturing such stators.
• the invention relates more particularly to synchronous or asynchronous alternating current machines. It relates in particular to traction or propulsion machines for electric (Battery Electric Vehicle) and/or hybrid (Hybrid Electric Vehicle - Plug-in Hybrid Electric Vehicle) motor vehicles, such as individual cars, vans, trucks or buses.
• the invention also applies to rotating electrical machines for industrial and/or energy production applications, in particular naval, aeronautical or wind turbine applications.
• US patent 10424979 relates to a stator comprising two packs of laminations comprising notches open towards the air gap.
• the two stacks of sheets are twisted, being separated by a non-electrically conductive central element, comprising a closed yoke and non-twisted straight teeth.
• this patent describes a specific insulation system for round wire.
• Patent application JP 2020 120536 relates to a non-twisted stator, comprising round wires, and equipped with a cooling fluid distribution plate arranged annularly between two stacks of stator laminations.
• the invention aims to meet all or part of this need and thus has as its object, according to one of its aspects, a method for manufacturing a stator for a rotating electrical machine, comprising the following steps:
• the sheets are stacked aligned, in particular not integral with each other and without angular offset between the sheets, then the stacks of sheets are twisted after insertion of the electrical conductors, which can make it possible to facilitate the insertion of the conductors electrical, which indeed thus takes place in one or more untwisted stacks.
• the twisting of the electrical conductors leads to the twisting of the stacks of sheets in which they are inserted.
• the laminations are forced by the electrical conductors to shift angularly relative to each other around the longitudinal axis X of the stator.
• the electrical conductors are used to twist the sheets which are only stacked on top of each other without any mechanical effort, which avoids in particular any effort on any insulation of the electrical conductors.
• step (c) of twisting the twisting of the stacks of sheets can be accompanied from the outside, for example by means of rotary cams supported by twisting plates.
• step (a) the sheets can be stacked on an expanding mandrel.
• step (a) you can insert at least one spacer between certain sheets.
• the spacer thus inserted between the sheets can be intended to separate two stacks of consecutive sheets.
• the spacer makes it possible to maintain the laminations of the first stack of laminations during this step (e) of twisting of the conductors.
• the sheets of insulation may not be continuous over the entire length of the stator.
• the insulation sheets can be continuous along the entire length of the stator.
• the method may include the following additional step:
• the step (a') of inserting the insulation device can take place after the step (a) of supplying, in particular after the step of insulation, and before the step (b) of inserting the conductors electrical.
• the method may include the following additional step:
• Step (d) of separation can be carried out by means of the aforementioned extensible mandrel.
• Step (d) of separation can take place after step (b) of inserting the electrical conductors and before step (c) of twisting.
• the method may include the following additional step:
• the insertion step (e) can take place after the separation step (d) and before the twisting step (c).
• the twisting tools can have the shape of fingers. Each twisting tool can be inserted between two circumferentially consecutive electrical conductors.
• the set of twisting tools can comprise a plurality of sets of twisting tools, for example a set at each of the ends of the stator and one or more sets between two stacks of consecutive sheets.
• Each set may include twisting tools that are circumferentially distributed, in particular regularly distributed.
• Step (e) of inserting the twisting tools can take place after step (b) of inserting the electrical conductors, after step (d) of separation and before step (c) of twisting.
• the twisting step (c) can be implemented using the aforementioned twisting tools. Twisting tools make it possible to exert circumferential pressure on electrical conductors, in order to deform them to twist them.
• step (c) bundles of sheets are obtained.
• the twisting tools can be removed.
• the shape of the stack of laminations observed in a plane containing the longitudinal axis X of the stator on either side of the twisting tools can be that left on the electrical conductors of the winding by the twisting tools.
• the shape may be that of a stack in an arc of a circle.
• the shape could alternatively be straight with rounding in connection with the two end packages.
• the bundles of sheets can be clamped axially, then proceed to their welding.
• the same U-shaped electrical conductor can be placed in two different, non-consecutive slots in the stator mass of the stator. If an electrical conductor is U-shaped, it can be welded to two other electrical conductors on the same side of the machine.
• a further subject of the invention is a rotating electrical machine stator manufactured by the process described above.
• the invention also relates, independently or in combination with the foregoing, to a stator for a rotating electrical machine, comprising a stator mass formed from a stack of sheets, comprising notches, electrical conductors housed in the notches, in particular at the at least some of the electrical conductors, or even a majority of the electrical conductors, better still all the electrical conductors, being in the shape of a U-shaped or I-shaped hairpin, the stator mass being composed of a plurality of packets arranged consecutively along a longitudinal axis X of the stator, the laminations of at least one package, preferably of all the packages, being angularly offset from each other around the longitudinal axis of the stator, the laminations of the first package being angularly offset in a direction and the laminations of the second package being angularly offset in the other direction, the stator mass being devoid of protuberance on its outer surface.
• a protrusion can be used in the prior art to deform the electrical conduct
• stacks of sheets and the electrical conductors inserted therein are deformed with the method described above.
• the stacks may have no gripping means. Once the twisting of the stacks of sheets has been carried out, packets of sheets are obtained.
• the stator according to the invention makes it possible to improve the noise and vibration reduction performance of the resulting machine, as well as the cooling of the machine.
• the invention also makes it possible to reduce the total cost of the machine, by making it possible to simplify the assembly of the rotor with a stack of sheets in a single angular orientation, with an interface between the rotor and a shaft of the simplified machine.
• the laminations of the stator lamination stack are magnetic.
• the stator mass comprises teeth defining between them the notches, the teeth being attached to a yoke of the stator.
• the electrical conductors may have an inclined shape, due to the angular offset between the sheets.
• the electrical conductors have a change in inclination, in particular at the level of the aforementioned spacer or a change of package. They can thus have a double inclination, in one direction then in the opposite direction. The two inclinations can have the same angle in absolute value.
• the electrical conductors may have a curvilinear shape. This curvilinear shape may result from the bending of the electrical conductors during the realization of the inclination.
• the stator according to the invention may have no weld bead protruding from the outer surface of the stator mass. It may for example be devoid of protuberance on its outer surface. It may have no input means. This can facilitate its insertion into a crankcase. Indeed, the stator is then advantageously devoid of external protrusion which would be restrictive for shrinking in a casing or devoid of grooves in the yoke which would degrade the exchange surface between the stacks and the casing, which is particularly advantageous when the crankcase is water cooled.
• the stator may however comprise at least one bead of welds of the laminations of the same package.
• the stator may for example comprise on the outer surface of the stator mass one or more lunes or specific shapes allowing welding.
• the weld bead may in particular be visible on the outer surface of the stator mass.
• the weld bead may in particular have an inclination with respect to the longitudinal axis X of the stator, due to the angular offset between the sheets.
• the inclination of the weld bead(s) can correspond to the value of the angular offset between the sheets.
• the stator may comprise one or more weld beads distributed angularly around the longitudinal axis X of the stator, for example two, three or four. They can in particular be regularly distributed angularly, in particular at 180°, or at 120°, or even at 90°.
• the weld beads can be continuous over the length of a packet, or even all the packets, or alternatively interrupted at the level of the possible spacer.
• the weld beads can advantageously be continuous over the length of all the packages, in particular when the spacer comprises metallic elements. Indeed, these metal elements allow the weld beads to extend from the first pack of sheets to the metal elements of the spacer and then to the second pack of sheets. This solution considerably improves the mechanical integrity of the stator before insertion into a casing or a firette.
• stator may have no spacer between two consecutive packages.
• the stacks of sheets may not be separated from each other. They may not be separated from each other by a spacer.
• two consecutive packets can be separated by a spacer.
• the spacer can be magnetic. It may comprise a magnetic material.
• the spacer separating the stacks of laminations can be non-magnetic. It may comprise a non-magnetic material. At the level of the non-magnetic spacer, there is therefore no circulation of magnetic flux.
• the spacer can be at least partially metallic, or even entirely metallic.
• the metal used can be magnetic or non-magnetic.
• the spacer can be at least partially made of a non-metallic material, for example plastic.
• the spacer may in one embodiment comprise a ring of plastic material, for example molded onto metal elements, for example of parallelepiped shape. These metal elements can have a mechanical role while the plastic used for the overmolding can facilitate the passage of the cooling fluid or integrate a thermal probe.
• the spacer may include cylinder head plates.
• the spacer cylinder head laminations can be magnetic or non-magnetic. They comprise a so-called yoke annular part, which is superimposed on a yoke of the stator mass. In particular, they may be devoid of teeth.
• the spacer may have teeth.
• the teeth of the spacer can be superimposed on a yoke of the stator mass.
• the teeth of the spacer can be inclined with respect to the longitudinal axis of the stator, or not be inclined.
• the teeth of the spacer can be placed radially in line with the notches of the stator mass.
• the spacer may advantageously include teeth, in particular when there is continuity of the slot insulation between two stacks of laminations of the stator mass.
• the spacer teeth can span the yoke width of the stator when aligned with the slots in the stator, improving the thermal performance of the machine.
• the spacer teeth may cover the yoke width of the stator as well as a portion of the corresponding stator tooth, when aligned with the stator teeth formed between the notches thereof, thereby improves the mechanical performance of the machine.
• the spacer may comprise a cylinder head part connecting the teeth of the spacer to each other.
• This yoke part can be superimposed with a yoke of the stator mass.
• the spacer may include a cylinder head part providing openings to the outside. Said openings can be made between the teeth mentioned above. The openings of the spacer can be placed radially in line with the teeth of the stator mass.
• the spacer can make it possible to constitute a fresh air inlet in the center of the machine, to favor the circulation of air in the stator, and thus to improve the machine cooling. This is particularly useful on a long machine.
• a stator according to the invention can also be useful on a machine comprising a water-cooled casing.
• the spacer according to the invention can make it possible to improve the cooling of the machine by creating a channel for the passage or supply of a cooling fluid, liquid or gaseous, such as air, oil or other.
• the rotor mass may comprise one or more vents for the passage of a cooling fluid, corresponding to openings in the spacer of the stator, to allow the flow of the cooling fluid. This can then flow through ducts formed by the assembly of the housing and the stator.
• the spacer may have a height measured along the longitudinal axis of the stator of between 1 and 10 mm, better still between 2 and 8 mm, or even between 3 and 6 mm.
• the spacer may in particular have a height measured along the longitudinal axis of the stator of between one and three times the height of the slot insulators, being in particular approximately twice the height of the slot insulators projecting from the package, otherwise called overhang of the package insulators.
• 'Height of the notch insulators' means the height of the insulators which protrude from the notches of the stack of sheets. Such a height makes it possible to reduce the risks of short-circuit at the level of the interface between the consecutive packets, and to increase the arcing distance, in particular between the conductor and the mass.
• Each plate can be offset from the adjacent plate by an elementary angle.
• the elementary angle can be constant. Between two stacks of sheets, the elementary angle can be the same in absolute value. As a variant, the elementary angle may be different from one stack of sheets to another.
• the elementary angle of the angular offset between two consecutive sheets can be between 0.004° and 0.085°, being for example between 0.017° and 0.032°, better still between 0.008 and 0.016°, being for example of the order of 0.01 °.
• a total angular offset of a stack of sheets, measured between a first sheet and a last sheet of the stack of sheets, can be between 2 and 10°, being for example between 2.5 and 8°, better still between 3 and 6°, being for example of the order of 3.75°.
• the elementary angle of the angular offset between two consecutive laminations may correspond to the tooth pitch of the stator over the height of the package divided by the number of laminations in the package. In one embodiment, the elementary angle is equal to the tooth pitch divided by the number of sheets in the stack.
• the sum of the elementary angles of the packets can preferably be zero, in order to avoid an axial component.
• the angle chosen for the angular offset of a single packet can be identical to that used for the different packets in the case of V or W offset packets.
• Sheets in the same stack can be offset relative to each other by a constant elementary angle.
• all the laminations of each stack of the stator can be offset relative to each other by a constant elementary angle.
• the sheets of the same package can be offset from each other by a variable elementary angle, with for example a curvilinear variation.
• the stator mass may in one embodiment comprise two packets. As a variant, it may comprise more than two packets, in particular three or four or more.
• the stator mass may comprise an even number of packets. As a variant, the stator mass can comprise an odd number of packets.
• the laminations of the stator mass packages can all be angularly offset in the same direction around the longitudinal axis X of the stator.
• the laminations of the stator mass packages can be angularly offset in at least two directions, in particular in several directions, around the longitudinal axis X of the stator.
• the laminations of the stator mass packages can be angularly offset successively in one direction then in the other, being arranged in a V. They can be arranged in a V, being offset symmetrically with respect to a plane of symmetry perpendicular to the longitudinal axis X of the stator.
• the V arrangement with a twist in two different directions, makes it possible to minimize or even eliminate the load exerted on the bearings of the rotor.
• the stator mass may comprise a single central package cut in two by said plane of symmetry.
• the stator mass can comprise two central packets separated by said plane of symmetry. The two central packets may not be angularly offset relative to each other.
• the stator may comprise two packs of laminations, a first pack of laminations offset angularly in one direction, and a second pack of laminations offset angularly in the other direction.
• the elementary offset angles can have the same absolute value. This can advantageously make it possible to completely cancel the axial component of the torque on the rotor.
• the laminations of the stator mass packages can be angularly offset successively in one direction then in the other, being arranged in a herringbone pattern.
• the chevrons are arranged symmetrically.
• All of the stator packages may each have the same length, or alternatively different lengths.
• Two packets can have different lengths.
• the arrangement of the bundles in the stator mass may be such that the length of the bundles may increase and then decrease as one moves along the axis of the stator, or increase all the way along the stator, or decrease all the way. along the stator.
• the sum of the angular offset angles of the packets can be zero.
• the length of the bundles may vary with a sawtooth variation as one moves along the axis of the stator.
• the central packet or packets may have a different length from the other packets, for example a shorter or longer length.
• the slots in the stator can be closed.
• closed notch is meant notches which are not open radially towards the air gap.
• At least one notch, or even each notch can be continuously closed on the air gap side by a bridge of material coming in one piece with the teeth defining the notch. All the notches can be closed on the air gap side by bridges of material closing the notches. The material bridges may be integral with the teeth defining the notch. The stator mass then has no cutout between the teeth and the bridges of material closing the slots, and the notches are then continuously closed on the side of the air gap by the bridges of material coming from a single piece with the teeth defining the notch.
• the notches can also be closed on the side opposite the air gap by a yoke in one piece with the teeth or added. The notches are then not open radially outwards.
• the stator mass may have no cutout between the teeth and the yoke.
• each of the notches has a continuously closed contour.
• continuously closed is meant that the notches have a continuous closed contour when viewed in cross section, taken perpendicular to the axis of rotation of the machine. You can go all the way around the notch without encountering a cutout in the stator mass.
• the stator mass can be made by stacking magnetic laminations, the notches being made by cutting the laminations.
• the closing of the slots on the side of the air gap is obtained by bridges of material coming from a single piece with the rest of the laminations forming the stator mass.
• the stator may be devoid of added magnetic shims for closing the slots. This eliminates the risk of accidental detachment of these wedges.
• At least some of the electrical conductors, or even a majority of the electrical conductors, better still all the electrical conductors, can be in the shape of a U- or I-shaped hairpin.
• the stator may include two electrical conductors per slot.
• the stator may in one embodiment comprise two columns of electrical conductor strands.
• the electrical conductors can form a distributed winding.
• the winding can be corrugated or interleaved.
• the winding may not be concentrated or tooth wound.
• Electrical conductors can form a whole or fractional winding.
• Each electrical conductor may comprise one or more strands (“wire” or “strand” in English).
• strand is meant the most basic unit for electrical conduction.
• a strand can be of round cross section, we can then speak of 'thread', or flat.
• the flat strands can be shaped into pins, for example U or I.
• Each strand is coated with an insulating enamel.
• the electrical conductors can form a single winding, in particular whole or fractional.
• single winding it is meant that the electrical conductors are electrically connected together in the stator, and that the connections between the phases are made in the stator, and not outside the stator, for example in a terminal box. .
• a winding is made up of a number of phases m staggered in space in such a way that when they are supplied by a multi-phase current system, they produce a rotating field.
• the winding can be whole or fractional in the invention.
• the winding can be full-pitch with or without shortening, or in a fractional variant.
• the electrical conductors form a fractional winding, in particular with a shortened pitch.
• the number of notches of the stator can be between 18 and 96, better still between 30 and 84, being for example 18, 24, 27, 30, 36, 42, 45, 48, 54, 60, 63, 72, 81 , 92, 96, better being 48 or 60 or 63.
• the number of poles of the stator can be between 2 and 24, or even between 4 and 12, being for example 6 or 8.
• the combination number of notches/number of poles of the stator can be chosen from the combinations of the following list, which is not exhaustive: 30/4, 42/4, 45/6, 48/8, 63/6, 60/8, 84/8.
• At least one first electrical conductor housed in a first notch can be electrically connected to a second electric conductor housed in a second notch, at the exit from said notches.
• the stator may comprise a phase connector comprising metallic elements connected to electrical conductors of the stator.
• the metal elements can be arranged radially externally or internally with respect to the electrical conductors to which they are connected.
• the metal elements connected to conductors of the stator windings can be held by an insulating support.
• the phase connector may have lugs for connection to a power supply bus. The machine can thus be connected to an inverter, electrically connected to the connection tabs of the connector.
• Electrical conductors at least, see a majority of electrical conductors, can be pin-shaped, U-shaped or I-shaped.
• the pin can be U-shaped ("U-pin” in English) or straight, being in form of I (“I-pin” in English).
• the hairpin and flat electrical conductors increase the filling factor of the slot, making the machine more compact. Thanks to a high filling coefficient, heat exchanges between the electrical conductors and the stator mass are improved, which makes it possible to reduce the temperature of the electrical conductors inside the slots.
• stator can be facilitated thanks to the electrical conductors in the form of pins.
• the pins do not require having open notches, we can have closed notches which allow the pins to be held and we can therefore eliminate the step of inserting the stator wedges.
• Electrical conductors extend axially in the slots.
• the electrical conductors can be introduced into the corresponding slots by one or both axial ends of the machine.
• An I-shaped electrical conductor has two axial ends each placed at one of the axial ends of the stator. It passes through a single notch, and can be welded at each of its axial ends to two other electrical conductors, at the axial ends of the stator.
• the stator may for example comprise 6, 10, 12, 14, 18, 22 or 26 I-shaped electrical conductors, the other electrical conductors all being able to be U-shaped.
• the stator may be devoid of an I-shaped electrical conductor.
• a U-shaped electrical conductor has two axial ends both placed at one of the axial ends of the stator. These two axial ends are defined by the two legs of the U. It passes through two different notches, and can be welded at each of its axial ends to two other electrical conductors, at the level of a same axial side of the stator.
• the bottom of the U that is to say the side of the U forming the bun or coil head, is arranged on the other axial side of the stator.
• At least a portion of the electrical conductors, or even a majority of the electrical conductors, may be U-shaped hairpin.
• the size of the electrical conductors at the level of the coil heads is reduced. This facilitates the interweaving of electrical conductors.
• each electrical conductor may comprise one or more strands (“wire” or “strand” in English).
• strand we mean the most basic unit for electrical conduction.
• a strand can be of round cross section, we can then speak of a 'thread', or flat.
• the flat strands can be shaped into pins, for example U or I.
• Each strand is coated with an insulating enamel.
• each notch can comprise several conductors and/or several strands makes it possible to minimize the losses by induced currents, or AC Joule losses, which evolve with the square of the supply frequency, which is particularly advantageous at high frequency and when the running speed is high. Heat transfer to the cold source is also facilitated. It is thus possible to obtain better performance at high speed.
• each electrical conductor may comprise several pins, each forming a strand, as explained above. All the strands of the same electrical conductor can be electrically connected to each other at the exit from the notch. The strands electrically connected to each other are placed in short circuit. The number of strands electrically connected together can be greater than or equal to 2, being for example between 2 and 12, being for example 3, 4, 6 or 8 strands.
• Several strands can form the same electrical conductor.
• the same electric current of the same phase circulates in all the strands of the same electrical conductor.
• All the strands of the same electrical conductor can be electrically connected to each other, in particular at the exit from the notch.
• All the strands of the same electrical conductor can be electrically connected to each other at each of their two axial ends, in particular at the exit from the notch. They can be electrically connected in parallel.
• each electrical conductor has three strands.
• a notch can therefore house six strands, for example, distributed between the two electrical conductors.
• a slot has four electrical conductors. Each electrical conductor may comprise two strands. The notch then houses eight strands, distributed between the four electrical conductors.
• the strands of the same electrical conductor can be in contact two by two over their entire length. They may in particular be in contact at the level of the coil heads. In addition, they may in particular be in contact at the weld ends. They can be joined. In one embodiment, the strands can be welded in pairs of three strands. Such a configuration allows good optimization of the space available in and around the stator. We gain in particular in compactness at the level of the height of the buns. In addition, the risks of short-circuiting between the electrical conductors can be reduced.
• the strands can be positioned in the notch so that their circumferential dimension around the axis of rotation of the machine is greater than their radial dimension. Such a configuration allows a reduction in losses by eddy currents in the strands.
• a strand can have a width of between 1 and 5 mm, being for example of the order of 2.65 or 3 mm.
• the width of a strand is defined as its dimension in the circumferential direction around the axis of rotation of the machine.
• a strand can have a height comprised between 1 and 5 mm, being for example of the order of 1.25 or 1.8 mm.
• the height of a strand is defined as its thickness in the radial dimension.
• the electrical conductors can be made of copper or aluminum, or any other enamelled conductive material or coated with any other suitable insulating coating.
• the stator mass can be produced by stacking sheets.
• the teeth can be interconnected by material bridges, and on the opposite side by a yoke.
• the notches can be closed. They can be produced entirely by cutting in the sheets. Each sheet of the stack of sheets can be monobloc.
• Each sheet is for example cut from a sheet of magnetic steel or sheet containing magnetic steel, for example steel 0.1 to 1.5 mm thick.
• the sheets can be coated with an electrically insulating varnish on their opposite faces before they are assembled within the stack. Electrical insulation can still be obtained by heat treatment of the sheets, if necessary.
• the stator may include an outer carcass surrounding the yoke.
• the stator teeth can be made with a stack of magnetic laminations, each covered with an insulating varnish, in order to limit the losses by induced currents.
• Another subject of the invention is a rotating electrical machine comprising a stator as defined above.
• the rotating electrical machine can be synchronous or asynchronous.
• the machine can be used as a motor or as a generator.
• the machine can be reluctance. It can constitute a synchronous motor or, as a variant, a synchronous generator. As a further variant, it constitutes an asynchronous machine.
• the maximum speed of rotation of the machine can be high, being for example greater than 10,000 rpm, better still greater than 12,000 rpm, being for example of the order of 14,000 rpm to 15,000 rpm. min, or even 20,000 rpm or 24,000 rpm or 25,000 rpm.
• the maximum speed of rotation of the machine may be less than 100,000 rpm, or even 60,000 rpm, or even even less than 40,000 rpm, better still less than 30,000 rpm.
• the invention may be particularly suitable for high-powered machines.
• the rotating electrical machine may include a rotor.
• the rotor may include a rotor mass.
• the rotor can be permanent magnets, with surface or buried magnets.
• the rotor can be flux concentrating. It may include one or more layers of magnets arranged in an I, U or V. Alternatively, it may be a wound or squirrel cage rotor, or a variable reluctance rotor.
• the rotor mass can extend along the axis of rotation and arranged around a shaft.
• the shaft may include torque transmission means for driving the rotor mass in rotation.
• the rotor may include permanent magnets inserted into the rotor mass.
• the rotor mass may comprise rotor laminations.
• the housings for the permanent magnets can be produced entirely by cutting in the sheets. Each sheet of the stack of sheets can be monobloc.
• it may be a wound or squirrel cage rotor, or a variable reluctance rotor.
• the rotor can be provided with a vent aligned axially with the spacer of the stator, which can advantageously make it possible to constitute a circulation of a cooling fluid in the machine.
• the number of pairs of poles p at the rotor is for example between 1 and 24, being for example 1, 2, 3, 4, 5 or 6.
• the diameter of the rotor may be less than 600 mm, or even less than 400 mm, better still less than 300 mm, better still less than 200 mm, and greater than 40 mm, better greater than 60 mm, being for example between 80 and 160 mm.
• the shaft can be made of a magnetic material, which advantageously makes it possible to reduce the risk of saturation in the rotor mass and to improve the electromagnetic performance of the rotor.
• the rotor comprises a non-magnetic shaft on which the rotor mass is arranged.
• the shaft can be made at least in part from a material from the following list, which is not exhaustive: steel, stainless steel, titanium or any other non-magnetic material.
• the rotor mass can in one embodiment be placed directly on the non-magnetic shaft, for example without an intermediate rim.
• the rotor may comprise a rim surrounding the shaft of the rotor and coming to rest on the latter.
• the rotor mass may comprise one or more holes to lighten the rotor, to allow its balancing or for the assembly of the rotor plates constituting it. Holes can allow passage of the tie rods now integral with the sheets.
• Each sheet is for example cut from a sheet of magnetic steel or sheet containing magnetic steel, for example steel 0.1 to 1.5 mm thick.
• the sheets can be coated with an electrically insulating varnish on their opposite faces before they are assembled within the stack. Electrical insulation can still be obtained by heat treatment of the sheets, if necessary.
• Sheets can be cut in a tool one after the other. They can be stacked and clipped or glued into the tool, in complete bundles or sub-bundles. The sheets can be clicked on top of each other. Alternatively, the stack of sheets can be stacked and welded outside the tool.
• the rotor mass may have an outer contour which is circular or multi-lobed, a multi-lobed shape being useful for example to reduce torque ripples or current or voltage harmonics.
• the rotor may comprise at least one flange which may be arranged at one end of the pack of rotor laminations.
• the rotor comprises two flanges each disposed at one end of the pack of rotor laminations.
• the rotor is not twisted, being straight.
• the rotor can be cantilevered or cantilevered from the bearings used to guide the shaft.
• the machine may comprise a single inner rotor or, as a variant, an inner rotor and an outer rotor, arranged radially on either side of the stator and coupled in rotation.
• the machine can be inserted alone into a casing or inserted into a gearbox casing. In this case, it is inserted into a casing which also houses a gearbox.
• Figure 1 is a perspective view, schematic and partial, of a stator according to the invention.
• FIG 2 is a perspective view, schematic and partial, of the stator of Figure 1 during manufacture.
• FIG 3 is a perspective view, schematic and partial, of the stator of Figure 1 during manufacture.
• FIG 4 is a perspective view, schematic and partial, of the stator of Figure 1 during manufacture.
• FIG 5 is a perspective view, schematic and partial, of the stator of Figure 1 during manufacture.
• FIG 6 is a perspective view, schematic and partial, of the stator of Figure 1 during manufacture.
• FIG 7 is a perspective view, schematic and partial, of the stator of Figure 1 during manufacture.
• FIG 8 is a perspective view, schematic and partial, of the stator of Figure 1 during manufacture.
• FIG 9 is a perspective view, schematic and partial, of the stator of Figure 1 during manufacture.
• FIG 10 is a perspective view, schematic and partial, of the stator of Figure 1 during manufacture.
• FIG 11 is a perspective view, schematic and partial, of the stator of Figure 1 during manufacture.
• stator 1 of a rotating electrical machine comprising a stator mass 2 comprising notches 3 and teeth 4 defining between them the notches, the teeth being attached to a yoke 57.
• the notches of the stator are closed.
• the stator 1 comprises a winding comprising electrical conductors 10 housed in the notches 3.
• the stator comprises two electrical conductors 10 per notch.
• the electrical conductors 10 are generally rectangular in cross section, with rounded corners. They are in the example described superimposed radially in a single row. The circumferential dimension of an electrical conductor corresponds substantially to the width of a notch.
• the electrical conductors 10 are made of copper or aluminum, or any other enamelled conductive material or coated with any other suitable insulating coating.
• the electrical conductors 10 are in the shape of a U-shaped hairpin. They each comprise first and second legs intended to extend axially respectively in first and second notches of the stator.
• the stator mass 2 is formed from a stack of magnetic laminations, and is composed of two packets 5 arranged consecutively along a longitudinal axis X of the stator.
• the two packets 5 each have the same length.
• the laminations of the packages are angularly offset from each other around the longitudinal axis of the stator, as shown in figure 1.
• Each sheet is offset from the adjacent sheet by an elementary angle.
• the elementary angle is constant.
• the elementary angle of the angular offset between two consecutive sheets can be in the example described of the order of 0.01°. Its value can vary from 0° excluded to a value equal to the tooth pitch.
• the sheets of the packages 5 of the stator mass 2 are angularly offset successively in one direction then in the other, being arranged in a V, the sheets of the first package being angularly offset in one direction and the sheets of the second package being angularly offset in the 'other way.
• the V arrangement with a twist in two different directions, makes it possible to minimize or even eliminate the load exerted on the bearings of the rotor.
• the two consecutive packets 5 are directly attached to each other.
• the stator shown does not have a spacer between two consecutive packages.
• the stator mass has no protuberance on its outer surface, and in particular no weld bead on the outer surface of the stator mass.
• the stator comprises oblique ribs 30 which serve to accompany the sheets during the twisting of the stack of sheets, then locations for the production of the weld seams of the sheets of the same package 5, which can be visible on the surface exterior of the stator mass 2, once the packages 5 have been welded, but without protruding from the outer surface of the stator mass.
• the resulting weld beads have an inclination with respect to the longitudinal axis X of the stator, due to the angular offset between the sheets. This inclination corresponds to that of the angular offset between the sheets.
• a set 9 of electrical conductors 10 in the form of a pin and a plurality of stacks of sheets 5 are provided.
• the stacks of sheets can be combined into a set sheets, as shown in Figure 2.
• the sheets can be stacked on an expanding mandrel, directly on top of each other.
• the stacks of sheets may not be separated from each other. They may in particular not be separated from each other by a spacer.
• step (a′) It is then possible to proceed with the insulation of the stacks of sheets in step (a′) by inserting into the stacks of sheets an insulation device 12 visible in isolation in FIG. 2, namely by inserting into the notches of the stacks of sheets of the insulating sheets, as illustrated in Figure 3. Also seen in Figure 3 is the assembly 9 of electrical conductors 10.
• Step (a′) of inserting the insulation device 12 can take place after step (a) of supplying, and before step (b) of inserting the electrical conductors described below.
• the method may include the following additional step:
• This step (d) of separation can be carried out by means of the aforementioned extensible mandrel.
• Step (d) of separation can take place after step (b) of inserting the electrical conductors and before step (c) of twisting.
• the method may include the following additional step:
• the insertion step (e) can take place after the separation step (d) and before the twisting step (c).
• the twisting tools can have the shape of fingers. Each twisting tool 20 can be inserted between two circumferentially consecutive electrical conductors, as illustrated in FIG. 7.
• FIG. 7 shows the twisting tools 20 fully inserted between the stacks of sheets.
• the set of twisting tools 20 may comprise a plurality of sets of twisting tools, for example a set at each of the ends of the stator and one or more sets between two stacks of consecutive sheets. Each set may comprise twisting tools 20 circumferentially distributed.
• Step (e) of inserting the twisting tools can take place after step (b) of inserting the electrical conductors, after step (d) of separation and before step (c) of twisting.
• step (c) illustrated in FIG. 8 the electrical conductors are twisted, in particular in two directions, to cause the twisting of the stacks of sheets, by means of the aforementioned twisting tools 20.
• the twisting tools make it possible to exert circumferential pressure on the electrical conductors 10, in order to deform them to twist them.
• the stacks of sheets are twisted after insertion of the electrical conductors.
• the twisting of the electrical conductors leads to the twisting of the stacks of sheets in which they are inserted.
• the laminations are forced by the electrical conductors to shift angularly relative to each other around the longitudinal axis X of the stator, and the stator shown in Figure 9 is obtained.
• the electrical conductors thus exhibit a change in inclination. They thus have a double inclination, in one direction then in the opposite direction.
• the two inclinations have in this example the same angle in absolute value.
• step (c) bundles of sheets are obtained.
• the bundles of sheets are clamped axially, as illustrated in FIG. 10, then they are welded from the outside.

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

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Publications (1)

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• 2021
  • 2021-07-13 FR FR2107615A patent/FR3125365A1/fr active Pending
• 2022
  • 2022-07-08 EP EP22754466.5A patent/EP4371214A1/de active Pending
  • 2022-07-08 WO PCT/FR2022/051373 patent/WO2023285755A1/fr active Application Filing

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