Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K3/00—Details of windings
  • H02K3/04—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
  • H02K3/24—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors with channels or ducts for cooling medium between the conductors
• • 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
• • 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
  • H02K9/197—Arrangements for cooling or ventilating for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil in which the rotor or stator space is fluid-tight, e.g. to provide for different cooling media for rotor and stator

Definitions

• the invention relates to a rotary electrical machine of the type comprising a housing and a stator received clamped in the housing, as well as a means for cooling the stator.
• a rotating electrical machine such as a high-power electric motor for moving a motor vehicle
• an electric motor which comprises a stator body made from a stack of blades or magnetic plates in which notches are arranged making it possible to receive the stator winding. These notches are oriented longitudinally.
• the document describes the placement of liners delimiting, with the longitudinal end faces of the stator body, annular cooling chambers around the coil heads in which a cooling fluid circulates between the turns of the coil heads.
• Each of the chambers thus formed has their own cooling fluid inlet and outlet, this makes it possible to ensure controlled cooling of the coil heads.
• the part of the winding which is in the stator body is not properly cooled.
• An object of the invention is to provide a rotating electrical machine in which the stator winding is cooled in a controlled and optimal manner.
• a rotary electrical machine comprising a casing, a stator comprising a stator body fixed in the casing and comprising first and second longitudinal end faces, notches formed and extending longitudinally in the stator body between the first and second longitudinal end faces, a coil longitudinally traversing the stator body through the notches and having first and second sets of protruding spool heads from at least one of the first and second longitudinal end faces of the stator body, a first chamber in the form of a ring portion arranged around the first set of coil heads and a second chamber in the form of a ring portion arranged around the second set of coil heads, the first and second chambers being in fluid communication with each other through the notches, one of the first and second e chambers being a coolant inlet chamber and the other of the first and second chambers being a coolant discharge chamber such that a flow of coolant between the first and second annular chambers is forced into the notches during operation of the rotating electrical machine.
• the rotary electric machine according to the invention has at least one of the following technical characteristics
• first and second chambers are annular chambers
• the coil comprises a third set of coil heads projecting from the other of the first and second longitudinal end faces and the machine comprises a third chamber in the form of a ring portion arranged around the third set of spool heads and in fluid communication with the first and second chambers through the notches;
• the third chamber is an annular chamber
• the first and second chambers are semi-annular chambers
• the third chamber is delimited by a liner integrally formed with a wall of the casing;
• the first and second chambers are delimited by a liner integrally with a wall of the casing;
• the casing comprising first and second clamping bearings of the stator body, the sleeve is provided in the first and / or second clamping bearings;
• the machine comprises means for supplying coolant to the inlet chamber;
• the cooling fluid supply means are positioned in the upper part of the casing
• the machine comprises means for evacuating cooling fluid from the evacuation chamber;
• the cooling fluid discharge means are positioned in the lower part of the casing
• the sealing means comprise an annular seal located centripetally with respect to the notches; the notches have a closed shape in section;
• the notches have a radially centripetal opening, the machine further comprising a sleeve for closing the radially centripetal opening, coaxial with the stator body;
• the stator body comprises a longitudinal stack of stator blades or plates;
• the winding has a set of pins.
• the stator winding may comprise electrical conductors, at least some of these electrical conductors, or even a majority of these electrical conductors, being in the shape of a U-shaped or I-shaped pin.
• the hairpin and flat electrical conductors increase the fill coefficient of the notch, making the machine more compact. Thanks to a high filling coefficient, the thermal 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. The energy efficiency of the electric machine is thus improved.
• the manufacture of the stator can be facilitated by virtue of the electrical conductors in the form of pins.
• the winding with pins can be easily changed by changing only the connections between the pins at the coil heads.
• the pins do not need to have open notches, we can have closed notches that allow the pins to be held and we can therefore eliminate the step of inserting the stator shims.
• Electrical conductors extend axially in the notches.
• the electrical conductors can be introduced into the corresponding notches through 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 conductors electrical, at the axial ends of the stator.
• the stator may for example comprise six or twelve electrical conductors in the shape of an I, the other electrical conductors possibly all being in the shape of a U.
• a U-shaped electrical conductor has two axial ends both placed at one of the axial ends of the stator. It passes through two different slots, and can be welded at each of its axial ends to two other electrical conductors, at the same axial side of the stator. The bottom of the U is on the other axial side of the stator.
• each electrical conductor comprises 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 "wire”, or flat.
• the flat strands can be shaped into pins, for example a U or an I.
• Each strand is coated with an insulating enamel.
• notch having a closed shape in section denotes notches which are not open radially towards the air gap.
• the presence of the notches having a closed shape in section improves the performance of the electrical machine in terms of the quality of the magnetic field in the air gap, by minimizing the harmonic content and eddy current losses in the conductors electrical, and leakage flows in the notches, as well as the fluctuations of the magnetic field in the air gap and the heating of the machine.
• the presence of these notches having a closed section in section improves the mechanical rigidity of the stator, mechanically strengthening the stator and reducing vibrations.
• the coolant can be a gas, for example air, or a liquid, for example water or oil.
• FIG.1 is a schematic sectional view of a rotary electric machine according to one embodiment of the invention
• FIG.2 is a detail sectional view of part of one of the annular chambers of the machine of Figure 1;
• FIG.3 is a detailed schematic sectional view of a notch, according to a first embodiment, of the stator body of the machine of Figure 1;
• FIG.4 is a three-dimensional view of a stator body comprising a second embodiment of the notches.
• FIG.5 is a detailed schematic sectional view of a notch in Figure 4.
• the rotary electrical machine 1 comprises a casing 10 formed, here, of a first casing cover 12, of a casing body 1 1 and of a second casing cover 13.
• the electric machine rotary 1 according to the invention further comprises, provided within the housing 10, a rotor 50 mounted fixedly on a rotor shaft 51.
• the rotor shaft 51 is held in the casing 1, free to rotate, by a bearing 52 in the casing cover 12 and by a bearing 53 in the second casing cover 1 3.
• the rotary electrical machine 1 comprises a stator 40 fixedly mounted in the casing body 12 so as to completely surround the rotor 50.
• the stator 40 comprises, here, a stator body 41 and a coil 45 received longitudinally in the stator body 41 and having coil heads 42,43 projecting longitudinally on either side of the stator body 41 from longitudinal end faces 41 1 and 412 of the stator body 41.
• the stator body 41 can be either in one piece or a stack of stator blades, sheets or plates.
• the stator body 41 comprises a series of notches 44 extending longitudinally between the two longitudinal end faces 41 1, 412 in which the conductors of the coil 45 are received.
• the conductors may optionally be composed of multiple strands of electrically conductive material.
• the coil 45 is formed from a set of pins in electrically conductive material. In section, as illustrated in Figure 3, each notch 44 has a closed shape elongated radially. Once, the coil 45 in place, there are interstices between the various conductors and / or strands of the coil 45 passing through the notch 44 and between said conductors and / or strands and side walls of the notch 44.
• the housing body 1 1 is here of cylindrical shape and has a longitudinal dimension which is similar to a longitudinal dimension of the stator body 41 which is received, here, clamped in the housing body 1 January.
• the first casing cover 12 comprises a jacket 121, 122, 152 partly delimiting a first, here annular, cooling chamber 15.
• the jacket comprises a side wall 121 of the first casing cover 12, a radially outer annular part of a wall of bottom 122 of the first casing cover 12 and a radially internal wall 152 projecting from the bottom wall 122 and opposite and at a distance from the side wall 121.
• the wall 152 is integral with the first casing cover 12.
• the sleeve formed is integral with the first casing cover 12.
• the first cover housing 12 When mounting the rotary electrical machine 1 according to the invention, the first cover housing 12 bears on the housing body 1 1 and on a radially outer part of the longitudinal end face 41 1 of the stator body 41 at a free end of the side wall 121 and on a radially part internal of the longitudinal end face 41 1 of the stator body 41 at a free end of the wall 152 of the sleeve.
• the liner of the first casing cover 12 associated with the longitudinal end face 41 1 of the stator body 41 forms the first, here annular, cooling chamber 15 in which the first coil heads 43 of the winding 45 extend.
• the first coil heads 43 then form a first set of coil heads.
• the first casing cover 12 comprises fluidic communication means 151 in cooling fluid from the first annular cooling chamber 15.
• the fluidic communication means 151 is a duct portion extending longitudinally through it. the bottom wall 122 of the first casing cover 12 and located in the lower part of the casing 10.
• the second housing cover 13 comprises a jacket 131, 132,142 partially delimiting a second, here annular, cooling chamber 14.
• the jacket has a side wall 131 of the second housing cover 13, an annular part radially outer of a bottom wall 132 of the second casing cover 13 and a radially inner wall 142 projecting from the bottom wall 132 and opposite and at a distance from the side wall 131.
• the wall 142 is integral with the second casing cover 13.
• the sleeve formed is integral with the second casing cover 13.
• the second cover housing 13 When mounting the rotary electrical machine 1 according to the invention, the second cover housing 13 bears on the housing body 1 1 and on a radially outer part of the longitudinal end face 412 of the stator body 41 at a free end of the side wall 131 and on a radially inner part of the longitudinal end face 412 of the stator body 41 at a free end of the wall 142 of the sleeve.
• the liner of the second casing cover 13 associated with the longitudinal end face 412 of the stator body 41 forms the second, here annular, cooling chamber 14 in which the second coil heads 42 of the winding 45 extend.
• the second coil heads 42 then form a second set of coil heads.
• the second casing cover 13 comprises fluidic communication means 141 in cooling fluid from the second annular cooling chamber 14.
• the fluidic communication means 141 is a portion of duct extending radially through. the side wall 131 of the second casing cover 13 and located in the upper part of the casing 10.
• the first 12 and second 13 casing covers respectively form first and second clamping bearings of the stator body 41.
• sealing means 60 are provided at a connection between the first 15 and second 14 chambers and notches. More particularly, the sealing means 60 are here an annular seal which is sandwiched between the free end of the wall 152, respectively 142, of the sleeve and the longitudinal end face 41 1, respectively 412, of the body stator 41. Thus, this avoids a flow of cooling fluid from the cooling chambers to an air gap present between the stator 40 and the rotor 50.
• the cooling fluid is for example introduced by the fluid communication means 141, which then become cooling fluid intake means, into the second cooling chamber 14 which then forms a chamber coolant intake.
• the cooling fluid is injected under pressure so as to optimally occupy a volume of the second cooling chamber 14: thus the second set of coil heads 42 are completely bathed in the cooling fluid.
• the coolant enters the notches 44 and flows around and along the conductors and / or strands of the coil 45 in the previously described interstices. This flow of the cooling fluid is illustrated by the arrows visible in FIG. 2.
• the cooling fluid emerges from the notches 44 towards the first cooling chamber 15 which it fills completely, thus flooding the first set of coil heads 43. to cool them in turn optimally.
• the first cooling chamber 15 then forms a cooling fluid discharge chamber.
• the cooling fluid is finally discharged by the fluidic communication means 151, which then become means for discharging cooling fluid.
• the circulation of the cooling fluid can take place in the reverse manner.
• the notches 144 of the stator body 146 receiving the conductors and / or strands of the coil 45 have, in section, an open shape: the notches 144 comprise a radially centripetal opening 145 opening out at a radially internal face of the stator body 146.
• the sleeve 160 then completes the sealing means 60 described above.
• the sleeve 160 can be formed integrally with the wall 142 of the liner. Means are also provided for sealing the chamber at the connection between the sleeve and the bottom wall 132 of the second housing cover 1 3.
• the first set of coil heads is formed by a part of the first coil heads 43, for example and the second set of coil heads by a another part of the first coil heads 43.
• the first and second sets of coil heads project from the same longitudinal end face 41 1.
• the first cooling chamber arranged around the first set of coil heads is only shaped as a ring portion.
• the second cooling chamber arranged around the second set of coil heads is no longer in the shape of a ring portion.
• the ring portions of the first and second chambers form a complete ring.
• the first and second cooling chambers are semi-annular. Other partitions and number of cooling chambers are possible.
• the coil comprises a third set of coil heads formed by all or part of the second coil heads 42 projecting from the other 412 first 41 1 and second 412 longitudinal end faces.
• the third set of coil heads comprises the coil heads 42 associated with the notches 44 opening into the first cooling chamber, on the one hand, and on the other hand, the coil heads 42 associated with the notches 44 opening into the first cooling chamber. the second cooling chamber.
• the rotary electric machine 1 according to the invention then comprises a third cooling chamber in the form of a ring portion arranged around this third set of coil heads.
• this third cooling chamber is in fluid communication with the first and second cooling chambers through the notches 44.
• the first and second cooling chambers are therefore in fluid communication with each other via the aforementioned notches 44.
• the third cooling chamber is an annular chamber.
• the third cooling chamber is produced in the same way as the first 14 and second 15 cooling chambers, as described above for the embodiment of the rotary electrical machine 1 according to the invention illustrated in the appended figures.
• the cooling fluid is introduced by the fluidic communication means, which then become cooling fluid inlet means, into the first cooling chamber which then forms a cooling fluid inlet chamber.
• the cooling fluid is injected under pressure so as to optimally occupy a volume of the first cooling chamber: thus the first set of coil heads is completely bathed in the cooling fluid.
• the cooling fluid enters the associated notches 44 opening into the first cooling chamber and flows around and along the conductors and / or strands of the coil 45 in the previously described interstices.
• the cooling fluid leaves these notches 44 towards the third cooling chamber which it fills completely, thus flooding the third set of coil heads in order to cool them in turn optimally.
• the cooling fluid enters the associated notches 44 opening into the second cooling chamber and flows around and along the conductors and / or strands of the coil 45 in the interstices described above.
• the third cooling chamber forms a connecting chamber.
• the cooling fluid leaves these notches 44 towards the second chamber of cooling that it fills completely, thus flooding the second set of coil heads to cool them in turn optimally.
• the second cooling chamber then forms a cooling fluid discharge chamber.
• the cooling fluid is finally discharged by the fluidic communication means, which then become means for discharging cooling fluid, associated with the second cooling chamber.
• one of the first 12 and second 13 casing covers is integral with the casing body 1 1.
• the rotary electrical machine 1 according to the invention which has just been described allows cooling of the coil 45, and therefore of the stator 40, by direct contact of the cooling fluid with the conductors and / or strands of said coil 45 which is the source of heat to be removed from the stator 40 of the rotating electrical machine 1 according to the invention.
• the rotary electrical machine 1 according to the invention which has just been described can be a synchronous or asynchronous machine. It is in particular a machine for traction or propulsion of electric motor vehicles (Battery Electric Vehicle) and / or hybrids (Hybrid Electric Vehicle - Plug-in Hybrid Electric Vehicle), such as individual cars, vans, trucks, buses, coaches.
• the rotating electric machine 1 according to the invention can be used in industrial and / or energy production applications, such as wind turbines, boats, submarines.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Motor Or Generator Cooling System (AREA)
• Windings For Motors And Generators (AREA)
• Iron Core Of Rotating Electric Machines (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=67185361

Family Applications (1)

Country Status (5)

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• 2019
  • 2019-02-28 FR FR1902099A patent/FR3093388B1/fr not_active Expired - Fee Related
• 2020
  • 2020-02-25 WO PCT/FR2020/050362 patent/WO2020174180A1/fr not_active Ceased
  • 2020-02-25 EP EP20713725.8A patent/EP3931942A1/fr not_active Withdrawn
  • 2020-02-25 JP JP2021551875A patent/JP2022529306A/ja active Pending
  • 2020-02-25 US US17/310,317 patent/US12176773B2/en active Active

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