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
  • H02K1/32—Rotating 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
  • H02K5/00—Casings; Enclosures; Supports
  • H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
  • H02K5/15—Mounting arrangements for bearing-shields or end plates
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K9/00—Arrangements for cooling or ventilating
  • H02K9/19—Arrangements for cooling or ventilating for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/70—Wind energy
  • Y02E10/72—Wind turbines with rotation axis in wind direction

Definitions

• the present invention relates to rotating electrical machines, and more particularly those cooled by circulation of a cooling liquid, in particular oil, circulating at least partially in the shaft of the machine and, where appropriate, in a stack of metal sheets.
• a cooling liquid in particular oil
• the invention relates more particularly to the rotors of such machines, and even more particularly to the flanges.
• 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.
• the machine comprises a flange in which is formed a conduit, which is of constant cross section from its inlet to its outlet, or with a single cross-section variation between two portions which are each of constant cross-section.
• the oil is introduced into the flange through an orifice oriented axially, on the side opposite the rotor mass. This flange is not supplied from a pack of rotor laminations of the rotor.
• a flange for the rotor of a rotating electrical machine comprising one or more channels for supplying a cooling liquid fed from a channel formed in a pack of rotor laminations or a shaft of the rotor or between the pack of rotor laminations and the shaft, at least one inlet channel having a narrowing in cross section, the cross section of the inlet channel decreasing then increasing when the one moves away from the axis of rotation of the machine.
• the constriction makes it possible to limit the flow of the coolant, and thus to promote its good distribution in the rotor, and on either side of it. This is particularly useful when the coolant is provided by a central supply, in particular a single supply. In the supply channel before the constriction, the pressure of the coolant is lower, which makes it possible to obtain a good distribution of the oil all around the axis of rotation of the rotor. It is thus possible to obtain improved cooling of the electrical conductors of the machine, thanks to a good distribution of the cooling liquid on each of them. Even with a low flow of coolant oil, a very even distribution of the coolant can be obtained all around the axis of rotation of the rotor on all the electrical conductors of the machine.
• cross-section of the supply channel it is necessary to understand a section taken in the plane perpendicular to the direction of flow of the cooling fluid in the supply channel.
• the cross-sectional area of the narrowing may be between 0.5 mm 2 and 5 mm 2 , better still between 0.7 mm 2 and 3 mm 2 , better still between 1 mm 2 and 2.5 mm 2 , being by example of the order of 1.7 mm 2 or 2.4 mm 2 .
• the shape of the cross-section of the constriction may be rectangular, square, circular, half-moon or other, this list not being exhaustive.
• the narrowing can preferably be located in a first half of the supply channel, when moving in the direction of circulation of the coolant.
• the narrowing can preferably be located in the first two fifths of the supply channel, when moving in the direction of circulation of the coolant, better in a first third, or even in a first quarter of the supply channel .
• the length of the intake channel is measured between its entry into the bottom of the flange, at shaft level, and the top of the flange, at air gap level.
• the channel or channels can be formed at least partially in the thickness of the flange.
• the channel(s) may be formed at least partially hollow on a face of the flange facing said pack of rotor plates.
• the channel(s) can lead to outlets arranged at the periphery of the flange, through which the coolant is projected onto a stator of the machine.
• Each output can be fed by at least one respective feed channel.
• the outlets can be hollow formed on a side of the flange facing said pack of rotor plates.
• the outlets can be oriented radially outwards.
• the outlets can be located on a radially outer edge of the flange, and/or on a face of the flange facing said stack of rotor laminations.
• Each flange may include a single output, or else between 1 and 8 outputs, for example 2, 4, 6 or 8. It may include for example an even number of outputs, or alternatively an odd number.
• the outputs of a flange can for example be regularly distributed around the flange, for example at 180° when the flange has 2 outputs, and at 90° when the flange has 4 outputs.
• the supply channels can be oriented radially.
• Each flange may include a single feed channel, or between 1 and 8 feed channels, for example 2, 4, 6 or 8. It may include for example an even number of feed channels, or alternatively a odd number.
• the supply channels of a flange can for example be regularly distributed around the flange, for example at 180° when the flange comprises 2 channels, and at 90° when the flange comprises 4 channels.
• the flange can have a larger longitudinal dimension comprised between 5 mm and 20 mm, better still between 8 mm and 15 mm, being for example of the order of 12 mm.
• the supply channels may each comprise an inlet on the side of the axis of rotation of the rotor, said inlets being interconnected at a radially inner end by an annular recess.
• each feed channel comprising for example an inlet portion flared in the direction of the axis of rotation of the rotor.
• the annular recess or the flared inlet portion(s) can be used to collect the cooling liquid coming from the rotor, and to distribute it in the various supply channels of the flange. Such a configuration makes it possible to promote a regular distribution.
• the area of the flared inlet portion measured in a plane perpendicular to the axis of rotation of the rotor may be between 10 mm 2 and 50 mm 2 , better still between 20 mm 2 and 40 mm 2 , being for example of the order of 30 mm 2 .
• the difference between the internal and external diameters of this recess can be between 1 mm and 6 mm, better still between 2 mm and 5 mm, being for example of the order of 3.5 mm .
• the annular recess may be delimited at least in part by the shaft.
• the annular recess can be delimited at least in part by a pack of rotor laminations.
• the annular recess may be delimited at least in part by the flange.
• the annular recess can be delimited by the shaft, by the pack of rotor laminations and by the flange.
• annular G can be located between the shaft and the narrowing of the inlet channel.
• An outer face of the flange can be configured to limit the presence of coolant in the air gap and promote its projection towards the electrical conductors of the machine.
• the flange may be a casting, being in particular made of aluminum or aluminum alloy, in particular by die casting.
• the geometry of the flange, with channels formed at the interface between the flange and the pack of rotor laminations or of simple shape, allows very simple manufacture without re-machining or drilling, or with Possible re-machining and drilling, but easy to make. Materials other than aluminum can be used.
• the flange can be produced by machining.
• the flange may also comprise one or more channels for supplying a coolant supplied from a pack of rotor laminations of the rotor, at least one supply channel comprising a portion for spraying the coolant, this spray portion being arranged in the second half of the supply channel, when moving in the direction of circulation of the coolant.
• the spray portion may be as described below.
• a further subject of the invention is a flange for the rotor of a rotating electrical machine, comprising one or more channels for supplying a cooling liquid supplied from a channel formed in a stack of metal sheets.
• rotors or in a shaft of the rotor or between the pack of rotor laminations and the shaft at least one supply channel comprising a coolant spray portion.
• This spray portion can be placed in the last two thirds of the supply channel, when moving in the direction of circulation of the coolant.
• the spray portion can be arranged in the second half of the supply channel, when moving in the direction of circulation of the coolant.
• the flange may include one or more of the characteristics described above or below.
• the spray portion breaks up the flow of coolant, and thus promotes the creation of a mist of droplets.
• droplet mist is meant a stream of coolant droplets. Coolant can mix with air. The coolant can thus be better distributed, in a balanced way, and thus a good distribution of it can be promoted in the rotor, and on either side of it, towards the electrical conductors of the machine. This is particularly useful when the coolant is provided by a central supply, in particular a single one.
• the invention makes it possible to burst the jet of cooling liquid, in order to obtain a mist of liquid on the electrical conductors of the rotating electrical machine.
• the droplets created can be projected towards the electrical conductors, in particular the coil heads. These droplets can pass through the coil heads at their base, which further promotes their cooling.
• the spray portion is closer to the air gap and the coil heads of the machine than to the axis of rotation. In particular, it is closer to the air gap and the coil heads than to the surface of the shaft.
• the spray portion may comprise a portion of channel formed through 360° in the flange.
• This channel portion may have a length of between 0.2 and 6 mm, better still between 1 and 4 mm, being for example of the order of 2.5 mm.
• the length of this channel portion may be between 0.4 and 11% of a radius of the flange, better still between 2 and 8%, being for example of the order of 5% of a radius of the flange.
• a greater transverse dimension of this channel may be between 1 and 5 mm, better still between 1.5 mm and 3 mm, being for example of the order of 2.5 mm.
• the cross-section of the supply channel can decrease and then increase when moving away from the axis of rotation of the machine.
• the channel portion can be obtained by drilling.
• It may extend along a longitudinal axis which extends in a plane perpendicular to the axis of rotation of the rotor.
• its longitudinal axis can be inclined with respect to this plane perpendicular to the axis of rotation of the rotor, for example by an angle comprised between 0° and 15°, better still between 0° and 10°, for example l order of 3°. It can for example be parallel to a face of the flange intended to come face to the stack of sheets.
• the spray portion of the inlet channel may include one or more barbs disposed across the flow of coolant.
• the pins can be molded, cast from the foundry with the rest of the flange.
• the pins can be produced by electroerosion, in particular with a copper matrix in a bath.
• the spikes can be attached to the flange.
• the pins can be re-machined, if necessary.
• the pimples can still be made by a 3D printing method.
• the pins can be oriented parallel to an axis of rotation of the rotor.
• the pins can be oriented perpendicular to a longitudinal axis of the supply channel.
• the spikes may be of generally cylindrical shape of revolution. They can be in cross section of generally discoid, elliptical, polygonal, square, rectangular or other, this list not being exhaustive. As a variant, the spikes can have the shape of a truncated cone. They may be flat at their free end, in order to promote good contact with the laminations of the stack of laminations.
• the flange may comprise, for a spray portion, a number of spikes comprised between 1 and 20, better still between 2 and 15, or even between 3 and 12, in particular 4.
• the spikes can be arranged in one or more rows, for example one, two or three rows, being for example arranged in staggered rows. In the case where the pins are in several rows, they can be staggered.
• the gap d between two pins measured between their longitudinal axes, can be between 0.5 mm and 5 mm, better still between 1 mm and 3 mm, being for example of the order of 2 mm.
• the pins can be arranged in regular staggered rows.
• a pin can be arranged at an equal distance from all the nearest pins, in all directions.
• the difference dl between two rows of pins, measured between their longitudinal axes, can be between 0.5 mm and 6 mm, better still between 2 mm and 5 mm, being for example of the order of 3.5 mm.
• the pins can be arranged in an irregular staggered row, with rows separated by a greater distance d2.
• the difference d2 can be between 1 mm and 7 mm, better still between 2 mm and 6 mm, being for example of the order of 4.5 mm.
• the spikes may have a diameter of between 0.5 mm and 4 mm, better still between 1 mm and 3 mm, being for example of the order of 2 mm.
• the spray portion may comprise four spikes distributed in three rows.
• the first and the third row can have one barb and the second row can have two barbs.
• the pins can be arranged in regular or irregular staggered rows.
• the spikes can all be equidistant from each other. Thus, there is no privileged passage for the cooling fluid which then flows uniformly in the supply channel.
• At least one spike in particular that or those of the third row, may comprise at least one fin, for example two fins.
• the fin(s) may extend along a plane perpendicular to the plane of the flange.
• the distance hl between the first row of spikes and the axis of rotation of the rotor can be between 10 mm and 50 mm, better still between 15 mm and 40 mm, being for example the order of 30 mm.
• the distance 11 between the centers of the two pins of the second row can be between 1 mm and 8 mm, better still between 2 mm and 6 mm, being for example of the order of 4 mm.
• the gap between the first and second row may be greater than the gap between the second and third row.
• the gap h2 between the first and the second row can be between 1 mm and 10 mm, better still between 2 mm and 6 mm, being for example of the order of 4.5 mm.
• the gap h3 between the second and the third row can be between 1 mm and 10 mm, better still between 2 mm and 5 mm, being for example of the order of 3.5 mm.
• the pin in the first row can particularly allow the jet to explode at low speed, that is to say at a speed of less than 5000 rpm.
• the second row of two spikes can particularly make it possible to burst the jet at all the speeds of rotation of the machine.
• the second row advantageously comprises two spikes in order to be able to burst the jet satisfactorily in both directions of rotation of the machine.
• the third row can make it possible in particular to break up the jet at all speeds and thus make it possible to form the mist of droplets.
• Each pin may have a free space around its periphery, that is to say a space where there is no other pin or an edge of the channel.
• This free space may have the shape of a disk, in particular centered on the spike.
• the free space When the free space is a disk, it may have a diameter of between 1 mm and 5 mm, better still between 2 mm and 4 mm, being for example of the order of 3 mm.
• the edges of the feed channel, at the level of the spray portion may have curved portions, in particular bumps and/or hollows.
• a dip corresponds to an increase in channel width and a bump corresponds to a reduction in channel width.
• the edges of the channel may have alternating dips and bumps.
• the edges of the channel, at the level of the spray portion can each have between 1 and 5 bumps, in particular 2 bumps.
• the edges of the channel, at the level of the spray portion can each have between 1 and 5 hollows, in particular 2 hollows.
• the edges of the channel each have two hollows and two bumps.
• the distance between two spikes can be substantially the same as the distance between a spike and a bump adjacent to this spike.
• the hollows may have different radii of curvature. For example, at least one of the hollows may have a greater radius of curvature than the other hollows.
• the edges of the channel may have small depressions and large depressions.
• the radius of curvature of the small hollows can be between 0.2 mm and 3 mm, better still between 0.5 mm and 2 mm, being for example of the order of 1 mm.
• the radius of curvature of the large hollows can be between 1 mm and 5 mm, better still between 2 mm and 4 mm, being for example of the order of 3 mm.
• a large hollow can be arranged between two bumps.
• the bumps can all have the same radius of curvature.
• the radius of curvature of the bumps may be equal to that of the small depression(s).
• the radius of curvature of the bumps can be between 0.2 mm and 3 mm, better still between 0.5 mm and 2 mm, being for example of the order of 1 mm.
• the bumps can be aligned with one or more nubs.
• the bumps can be offset, in particular slightly, with respect to one or more spikes.
• the distance h5 between the center of a bump and the center of an adjacent small hollow is between 0.5 mm and 5 mm, better still between 1 mm and 3 mm, being for example of the order of 1.7 mm .
• the recesses make it possible to provide sufficient space around the pins to allow the manufacture of the flange by foundry. Thanks to these spaces, it is possible to use pins that are sufficiently wide without the risk of the pins breaking and that the mold used is sufficiently strong.
• the ratio between the radius of curvature of the large hollows and the diameter of the spikes can be between 0.2 and 3, better still between 1 and 2, being for example of the order of 1.33.
• the distance 12 between the tops of two bumps arranged face to face can be between 1 mm and 10 mm, better still between 3 mm and 8 mm, being for example of the order of 6 mm.
• the distance 13 between the bottoms of two small hollows arranged face to face may be between 3 mm and 12 mm, better still between 4 mm and 10 mm, being for example of the order of 7.5 mm.
• the ratio of the distance 12 between the tops of two bumps arranged face to face to the diameter of the spikes can be between 1 and 6, better still between 1.5 and 5, being for example of the order of 3.
• the distance 13 between the bottom of a small hollow and a narrowing of a supply duct can be between 3 mm and 12 mm, better still between 5 mm and 10 mm, being for example of the order of 7.8 mm.
• a cross-sectional area of the spray portion can be between 3 mm 2 and 30 mm 2 , better still between 5 mm 2 and 25 mm 2 , being for example of the order of 15 mm 2 .
• the cross-sectional area of the spray portion is calculated by deducting that of any spikes.
• the shape of the cross-section of the spray portion can be rectangular, square, circular, half-moon or other, this list not being limiting.
• the spray portion can preferably be located in the last two fifths of the supply channel, when moving in the direction of circulation of the coolant, better in a last third, or even in a last quarter of the channel. ' brought.
• the length D2 of the inlet channel is measured between its entry into the bottom of the flange, at shaft level, and the top of the flange, at air gap level.
• the length D2 of the supply channel can be between 20 mm and 100 mm, better still between 25 mm and 80 mm, being for example of the order of 33 mm.
• the length D of the supply channel before the spray portion can be between 10 mm and 50 mm, better still between 15 mm and 40 mm, being for example of the order of 26 mm.
• a D/D2 ratio can be between 0.5 and 1, better still between 0.6 and 0.9, being for example of the order of 0.8.
• edges of the supply channels located between the inlet and the spray portion can be convex.
• the edges of the supply channels located between the inlet and the spray portion can be substantially rectilinear.
• the edges may be inclined at an angle g with respect to a plane containing the axis of rotation of the machine and tangent to a narrowing of the intake duct.
• the angle of inclination g can be between 150 and 30 ° , better still between 200 and 25 ° , for example of the order of 22.5°. A such an inclination makes it possible to direct the flow of cooling fluid in particular towards the pins furthest from the axis of rotation of the machine.
• the flange may include a flared end portion, in particular located after the spray portion, when moving in the direction of circulation of the coolant.
• the flared end portion opens onto the outer edge of the flange. It allows the coolant to be directed towards the stator, and in particular its electrical conductors, and in particular the coil heads.
• the flared end portion comprises a bottom inclined at an angle a with respect to a plane perpendicular to the axis of rotation of the rotor.
• the angle a can be between 2° and 30°, better still between 10° and 20°, being for example of the order of 15°.
• This inclined bottom gives access to the coolant up to the end of the flange.
• the flared end portion can form a flare angle b in this plane perpendicular to the axis of rotation of the rotor.
• the flare angle b can be between 10° and 50°, better still between 20° and 40°, being for example of the order of 30°.
• the flare angle b makes it possible to have a more or less wide area for spraying coolant on the coil heads.
• the flared end portion may include a notch arranged on the edge of the flange and oriented radially. This notch makes it easier to orient and index the flange.
• a further subject of the invention is a flange for the rotor of a rotating electrical machine, comprising one or more channels for supplying a cooling liquid fed from a pack of toric plates of the rotor , at least one supply channel comprising a coolant spray portion, this spray portion being arranged in the second half of the supply channel, when moving in the direction of circulation of the coolant, the flange further comprising at least one supply channel comprising a narrowing in cross-section, the cross-section of the supply channel decreasing and then increasing as one moves away from the axis of rotation of the machine.
• the narrowing may in particular be located in a first half of the supply channel, when moving in the direction of circulation of the coolant.
• the constriction and the spray portion can be separated by a channel portion in which the section cross section of the supply channel is wider than in the constriction and in the spray portion.
• the flange may comprise at least one supply channel comprising a coolant spray portion, this spray portion being arranged in the second half of the supply channel, when moving in the direction of circulation of the liquid. cooling, as well as a narrowing of cross-section, the cross-section of the channel of supply decreasing then increasing when one moves away from the axis of rotation of the machine.
• Another subject of the invention is a rotor comprising a pack of rotor laminations and at least one flange as defined above.
• the flange can be arranged at one end of the pack of rotor laminations.
• the subject of the invention is a rotor comprising a pack of rotor laminations and two flanges each disposed at one end of the pack of rotor laminations.
• At least one axial channel for distributing the coolant towards the flange(s) can be formed in the pack of rotor laminations or between the pack of rotor laminations and the shaft, along the latter. This or these axial distribution channels can pass axially through at least part of the laminations of the pack of rotor laminations.
• the circulation of the coolant in the rotor can be symmetrical with respect to a plane perpendicular to the axis of rotation of the rotor.
• each feed channel and/or G obviously annular and/or the flared portion(s) can face at least one axial distribution channel of the pack of rotor laminations.
• the rotor may comprise permanent magnets inserted in the pack of rotor laminations. It may comprise permanent magnets, with in particular surface or buried magnets.
• the rotor can be flux concentrating. It can include one or more layers of magnets arranged in an I, U or V.
• the housings for the permanent magnets can be made 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 number of poles P at the rotor is for example between 4 and 48, being for example 4, 6, 8, 10 or 12.
• the diameter of the rotor can be less than 400 mm, better still less than 300 mm, and greater than 50 mm, better still greater than 70 mm, being for example between 100 and 200 mm.
• 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 rotor magnetic mass may comprise salient poles.
• the poles can be integral with the rest of the rotor mass, or attached to it.
• 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 include one or more holes to lighten the rotor, 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.
• 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 can be cantilevered or cantilevered from the bearings used to guide the shaft.
• the rotor can be made in several sections aligned in the axial direction, for example at least two sections. Each of the sections can be offset angularly relative to the adjacent pieces (“step skew”).
• the coolant may be oil.
• the coolant can circulate in the housings of the permanent magnets, or between the shaft and the stack of laminations.
• the cooling liquid can be in direct contact with the permanent magnets of the rotor on part of an outer surface of said permanent magnets, so as to have a capture of the calories to be evacuated in an optimal manner and thus protect the permanent magnets of the rotor. “Direct contact” means physical contact with the outer surface of the permanent magnets, which may be covered with a protective varnish.
• Another subject of the invention is a rotating electrical machine, comprising a rotor as defined above.
• 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, or even even 20000 rpm or 24000 rpm or 25000 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 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.
• the machine has a stator.
• the latter comprises teeth defining notches between them.
• the stator may comprise electrical conductors, at least some of the electrical conductors, or even a majority of the electrical conductors, which may be in the shape of a U-shaped or I-shaped hairpin.
• the feed channel(s) may open out facing the ends of the stator coils.
• the ends of the stator windings are the parts of the electrical conductors of the stator that protrude from the stator mass.
• the machine may comprise a shaft traversed over at least part of its length by an internal channel for supplying the cooling liquid.
• the shaft may not have full length coolant flow in one direction. On the contrary, it can be traversed by a flow of coolant over approximately half of its length.
• the internal channel of the shaft may comprise a first axial portion over half the length of the shaft, and a second radial portion configured to conduct the coolant from the first portion towards the stack of laminations, and in particular towards the axial coolant distribution channel formed in the pack of rotor laminations or between the pack of rotor laminations and the shaft, along the latter.
• the notches can be at least partially closed.
• a partially closed notch makes it possible to create an opening at the level of the air gap, which can be used, for example, for the installation of electrical conductors for filling the notch.
• a partially closed notch is in particular made between two teeth which each have pole shoes at their free end, which close the notch at least in part.
• the notches can be completely closed.
• “fully 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 notches can be closed on the side of the air gap by material bridges 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 slots are then continuously closed on the air gap side by the bridges of material coming in one piece with the teeth defining the notch.
• the notches can also be closed on the side opposite the air gap by an added yoke or in one piece with the teeth. 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 stator mass can as a variant be produced by cutting in a mass of sintered or agglomerated magnetic powder. 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 sheets or the block 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.
• the stator may comprise coils arranged in a distributed manner in the slots, having in particular electrical conductors arranged in a row in the slots.
• distributed we mean that at least one of the coils passes successively through two non-adjacent slots.
• the electrical conductors may not be arranged in the notches loosely but in an orderly manner. They are stacked in the slots in a non-random manner, being for example arranged in rows of aligned electrical conductors.
• the stack of electrical conductors is for example a stack according to a hexagonal network in the case of electrical conductors of circular cross-section.
• the stator may include electrical conductors housed in the slots. 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 or straight, being I-shaped.
• 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.
• 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.
• 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 winding can be corrugated.
• the series connection of the electrical conductors can be done in so-called wavy winding.
• the term "wavy winding” means a winding in which the electrical conductors of the same phase and of the same pole are electrically connected to each other so that, for one winding path, the electric current of the phase circulates in the electrical conductors by rotating around the axis of rotation of the machine, always in one direction.
• the electrical conductors of the same phase and of the same pole do not overlap when observed perpendicular to the axis of rotation of the machine.
• the winding may comprise a single winding path or several winding paths.
• electrical conductor the current of the same phase flows by way of winding.
• winding path is meant all of the electrical conductors of the machine which are traversed by the same electric current of the same phase.
• These electrical conductors can be connected together in series or in parallel or in series-parallel. In the case where there is only one channel, the electrical conductors are connected in series. In the case where there are several channels, the electrical conductors of each channel are connected in series, and the channels are connected in parallel.
• the electrical conductors can thus form a distributed winding.
• the winding may not be concentrated or tooth wound.
• the stator has a concentrated winding.
• the stator may include teeth and coils disposed on the teeth.
• the stator can thus be wound on teeth, in other words with undistributed winding.
• the stator teeth may include pole shoes.
• the stator teeth are devoid of pole shoes.
• 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.
• the invention also relates, independently or in combination with the foregoing, to a method of manufacturing a rotor as defined above.
• a further subject of the invention is a method for cooling a rotating electrical machine as defined above.
• the cooling process may include the following step: circulating the coolant in opposite directions within the rotor, then spraying the coolant on the stator coil heads.
• Figure 1 is a longitudinal sectional view, schematic and partial, of a rotor made in accordance with the invention.
• FIG 2 Fa figure 2 is a front view of a flange of the rotor of figure 1.
• FIG 3 Fa figure 3 a sectional view, schematic and partial, of the flange of figure 2.
• FIG 4 Fa Figure 4 is a view similar to Figure 1 of an alternative embodiment.
• Figure 5 is a front view of a flange of the rotor of Figure 4.
• Figure 6 a sectional view, schematic and partial, of the flange of Figure 5.
• Figure 7 is a detail view, in section, of the flange of Figures 4 to 6.
• Figure 8 is a detail view, in section, of the flange of Figures 4 to 6.
• Figure 9a Figure 9a is a view similar to Figure 8 of an alternative embodiment.
• Figure 9b is a view similar to Figure 8 of an alternative embodiment.
• Figure 9c is a view similar to Figure 8 of an alternative embodiment.
• Figure 9d is a view similar to Figure 8 of an alternative embodiment.
• Figure 10a is a view similar to Figure 8 of an alternative embodiment.
• FIG. 10b Figure 10b is a perspective view of the flange of Figure 10a.
• Figure 10c is another perspective view of the flange of Figure
• Figure lOd is a view similar to Figure 6 of the flange of Figure
• Figure lia is a view similar to Figure 10a of an alternative embodiment.
• Figure 1 lb is a perspective view of the flange of Figure IIa.
• Figure 12 is a sectional view, schematic and partial, of a flange according to an alternative embodiment.
• FIG. 1 to 3 there is illustrated in Figures 1 to 3 an inner rotor 1 of a rotating electrical machine, also comprising an outer stator 2.
• the stator 2 makes it possible to generate a rotating magnetic field for driving the rotor 1 in rotation, within the framework of a motor synchronous, and in the case of an alternator, the rotation of the rotor induces an electromotive force in the electrical conductors 4 of the stator 2.
• the rotor 1 represented in FIG. 1 comprises a magnetic rotor mass 3 extending axially along the axis of rotation X of the rotor, this rotor mass being formed by a stack of magnetic toric laminations 8 stacked along the axis X, the plates being for example identical and superimposed exactly.
• the magnetic laminations are preferably made of magnetic steel. All grades of magnetic steel can be used.
• the rotor mass 3 has a central opening for mounting on a shaft 5.
• the shaft can, in the example considered, be made of a non-magnetic material, for example non-magnetic stainless steel or aluminum, or on the contrary be magnetic.
• the rotor 1 comprises two flanges 10 each placed at one end of the pack of rotor plates 8.
• Each of the flanges 10 comprises two supply channels 12 for a cooling liquid, both oriented radially and supplied from the pack of rotor laminations of the rotor.
• These two supply channels 12 are arranged at 180°, as can be seen in FIG. 2, and they are supplied from an axial channel 13 for distributing the coolant to the flange which is formed between the pack of rotor plates 3 and the tree 5, along this one.
• This axial distribution channel 13 is supplied by a central channel 51 of the shaft 5, which communicates with radial channels 52.
• the circulation of the cooling liquid in the rotor is thus symmetrical with respect to a plane perpendicular to the axis of X-rotation of the rotor.
• the supply channels 12 of the flanges 10 each have an inlet 12a on the side of the axis of rotation X of the rotor 1, said inlets being interconnected at a radially inner end by an annular recess 14.
• the annular recess 14 serves to collect the coolant coming from the rotor, and to distribute it in the two supply channels of the flange.
• the difference between the internal and external diameter of this recess is in the example described of the order of 3.5 mm.
• the supply channels 12 further comprise an outlet 12b on the opposite side, at the level of the coil heads of the electrical conductors 4.
• the outlets 12b are arranged at the periphery of the flange, on a radially outer edge of the flange, and oriented radially towards outside, allowing the coolant to spray onto the stator.
• the outlets are recessed on one face of the flange facing the packet of rotor plates 3, as seen in Figure 1.
• each flange has two outputs 12b, distributed around the flange at 180 °.
• the channel or channels are formed in the thickness of the flange, more precisely hollow on a face of the flange facing said pack of rotor laminations 8.
• Each of the two channels 12 further comprises a narrowing 15 of its cross-section, the cross-section of the supply channel 12 decreasing then increasing when one moves away from the axis of rotation X, which makes it possible to limit the flow rate. of the coolant, and thus to favor a good distribution of the latter in the rotor, and on either side of the latter.
• the area of the cross-section of the constriction 15 can be in the example described of the order of 1.7 mm 2 .
• the narrowing 15 is located in a first half of the supply channel, when moving in the direction of circulation of the coolant, close to the obviously annular G 14.
• each flange has an inclination oriented towards the shaft 5, which limits the presence of coolant in the air gap and promotes its projection towards the electrical conductors of the machine.
• each supply channel 12 comprises a spray portion 18 of the coolant, this spray portion 18 being arranged in the second half of the supply channel, when moving in the direction of circulation of the liquid. cooling.
• the spray portion 18 makes it possible to break up the flow of coolant, and thus to promote the creation of a mist of droplets.
• the cross-section of the supply channel decreases then increases as one moves away from the axis of rotation of the machine.
• the spray portion 18 comprises a portion of channel arranged 360° in the flange, which can be obtained by drilling.
• This channel portion here has a length 1 of the order of 2.5 mm.
• a greater transverse dimension of this channel is of the order of 2.5 mm.
• the spray portion of the supply channel comprises spikes 20 arranged across the flow of coolant. These pins 20 are molded, cast from the foundry with the rest of the flange.
• the pins 20 are in the example described oriented parallel to an axis of rotation of the rotor and perpendicular to a longitudinal axis of the feed channel 12.
• the pins 20 are of generally cylindrical shape of revolution, and in cross section of generally disc shape, as seen in Figure 5. They are also flat at their free end, in order to promote good contact with the sheets of the packet of sheets.
• the pins 20 are in this example arranged in two rows, here of two and three pins respectively, and staggered.
• the gap d between two pins, measured between their longitudinal axes, is of the order of 1 mm, as shown in Figure 8.
• the pins are in this example arranged in regular staggered rows, one pin being arranged at equal distance from all nearest pins, in all directions.
• the gap dl between two rows of pins, measured between their longitudinal axes, is around 1.7 mm.
• the pins could be arranged differently.
• Figure 9a they are arranged in three rows, here respectively of one, two and three pins, and in regular staggered rows as in Figure 8, with a spacing dl between two rows of pins which is here of l order of 1.7 mm.
• the spray portion 18 may have only one row, as shown in Figure 9b, which has a single row of three spikes.
• the pins can be arranged in an irregular staggered row, with rows separated by a greater distance d2, as illustrated in FIGS. 9c and 9d.
• the difference d2 can here be of the order of 3.7 mm.
• a cross-sectional area of the spray portion may be between 3 mm 2 and 30 mm 2 , being for example of the order of 15 mm 2 . It is calculated by deducting that of any spikes.
• the spray portion is located in the last two-fifths of the supply channel, of length D2, when moving in the direction of circulation of the coolant.
• the length D2 of the supply channel is measured between the entry of the latter into the bottom of the flange, at the level of the shaft, and the top of the flange, at the level of the air gap, as illustrated in FIG. 8 for example.
• the length D of the supply channel before the spray portion is of the order of 26 mm.
• a ratio D/D2 is for example of the order of 0.8.
• each supply channel comprises an inlet portion 12a flared in the direction of the axis of rotation of the rotor.
• the two flared inlet portions 12a make it possible to collect the cooling liquid coming from the rotor.
• the area of the flared inlet portion 12a measured in a plane perpendicular to the axis of rotation of the rotor is in the example described of the order of 30 mm 2 .
• the area of the cross section of the constriction 15 is of the order of 2.4 mm 2 .
• the shape of the cross-section of the constriction is in this example of substantially rectangular shape, as shown in Figure 7. Alternatively, it could be square, circular, half-moon or other shape, this list not being exhaustive .
• the supply channel 12 has a flared end portion 12b, located after the spray portion, when moving in the direction of circulation of the coolant.
• the flared end portion 12b opens onto the outer edge of the flange. It comprises a bottom inclined at an angle a with respect to a plane perpendicular to the axis of rotation of the rotor, as illustrated in figure 6.
• the angle a is here of the order of 15°.
• the flared end portion also forms a flare angle b in this plane perpendicular to the axis of rotation of the rotor, as shown in Figure 8.
• the flare angle b is here of the order of 30°.
• the spray portion 18 comprises four spikes 20 distributed in three rows.
• the first and the third row each have a barb 20 and the second row has two barbs 20.
• the gap h2 between the first and the second row is G of the order of 4.5 mm.
• the gap h3 between the second and third row is around 3.5 mm.
• the gap between the first and the second row is greater than the gap between the second and the third row, the pins 20 are therefore arranged in irregular staggered rows.
• the pin 20 of the third row has two fins.
• the diameter D′ of the spikes is of the order of 2 mm.
• the supply channel further comprises a narrowing 15 of its cross section. This constriction is arranged between the inlet 12a of the channel and the spray portion 18.
• Each pin has around its periphery a free space 21, that is to say a space where there are no other pins or an edge of the channel.
• This free space has the shape of a disc centered on the pin and with a diameter of about 3 mm.
• edges 121 of the channel at the level of the spray portion each have a large hollow 31, a small hollow 32 and two bumps 30,30'.
• the three pins of the second and third rows are arranged at an equal distance from each other.
• the distance between the pins is equal to the distance between each pin and the adjacent bump 30, 30'.
• the radius of curvature Ra of the small hollow 32 is of the order of 1 mm.
• the radius of curvature Rb of the large hollow 31 is of the order of 3 mm.
• the small hollow 32 is closer to the axis of rotation X than the large hollow 31.
• the large hollow 31 is arranged between the two bumps 30,30'. The small hollow 32 makes it possible to direct the flow of cooling fluid towards the two pins of the second row so that it is broken to form a mist of droplets.
• the 30.30' bumps all have the same radius of curvature Ra' which is around 1 mm.
• the bump 30 farthest from the axis X of rotation of the machine is aligned with the pin 20 of the third row.
• the bump 30' closest to the axis X of rotation of the machine is slightly offset with respect to the pin of the first row.
• the radius of curvature Ra of the small hollows is here equal to the radius of curvature Ra' of the bumps.
• the distance h5 between the center of the bump 30' closest to the axis of rotation of the machine and the center of the adjacent small hollow 32 is of the order of 1.7 mm.
• the flared end portion of the outlet 12b includes a notch 40 arranged on the edge of the flange and oriented radially to facilitate orientation and indexing of the flange.
• the edges 120 of the supply channel located between the inlet 12a and the spray portion 18 are convex.
• the ratio between the radius of curvature Rb of the large hollows and the diameter D' of the spikes is between 0.2 and 3, better still between 1 and 2, being for example of the order of 1.33.
• the distance 12 between the tops of the two bosses closest to the X axis of rotation which are face to face is between 1 mm and 10 mm, better still between 3 mm and 8 mm, being for example of the order of 6 mm.
• the distance 13 between the bottoms of the two small hollows closest to the X axis of rotation which are face to face is between 3 mm and 12 mm, better still between 4 mm and 10 mm, being for example of the order of 7.5mm.
• the ratio of the distance 12 between the tops of the two bumps closest to the axis X of rotation to the diameter D' of the pins 20 is between 1 and 6, better still between 1.5 and 5, being for example l order of 3.
• the distance hl between the first row of pins and the axis of rotation of the rotor is of the order of 30 mm.
• the distance 11 between the centers of the two pins 20 of the second row is of the order of 4 mm.
• the distance h4 between the center of the spike of the first row and the first bump 30' is between 0.2 mm and 3 mm, better still between 0.5 mm and 2 mm, for example is of the order of 1 mm.
• the gap 14 between the bottom of the small hollow 32 and the narrowing 15 is between 1 mm and 7 mm, better still between 2 mm and 5 mm, being for example of the order of 3 mm
• the distance h6 between the bottom of the small hollow closest to the X axis of rotation and the narrowing is between 3mm and 12mm, better still between 5mm and 10mm, being for example of the order of 7.8mm.
• edges 120 of the supply channel located between the inlet 12a and the spray portion 18 are substantially rectilinear.
• edges 120 of the feed channel are inclined at an angle g with respect to a plane P containing the axis of rotation of the machine.
• this angle g is of the order of 22.5°.
• FIG. 12 a sectional view of a flange according to a variant embodiment.
• the supply channels 12 of the flange 10 each have an inlet 12a on the side of the axis of rotation X of the rotor 1. These inlets are interconnected at a radially inner end by an annular recess 14.
• the bottom 140 of the annular recess is oblique.
• the bottom of the annular recess does not present a right angle unlike the embodiment of Figure 6.
• the invention is not limited to the examples which have just been described.
• the rotor can be made with other coolant passages, for example oriented radially at approximately mid-length of the package or in contact with the magnets.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Motor Or Generator Cooling System (AREA)

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• 2020
  • 2020-11-30 FR FR2012367A patent/FR3116963A1/fr active Pending
• 2021
  • 2021-11-23 US US18/254,376 patent/US12015328B2/en active Active
  • 2021-11-23 EP EP21823646.1A patent/EP4252334A1/de active Pending
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