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
  • H02K1/12—Stationary parts of the magnetic circuit
  • H02K1/14—Stator cores with salient poles
  • H02K1/146—Stator cores with salient poles consisting of a generally annular yoke with salient poles
• • 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
  • H02K1/18—Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures
  • H02K1/185—Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures to outer stators
• • 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
  • H02K1/27—Rotor cores with permanent magnets
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K21/00—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets
  • H02K21/12—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K19/00—Synchronous motors or generators
  • H02K19/02—Synchronous motors
  • H02K19/10—Synchronous motors for multi-phase current

Definitions

• the present invention relates to the field of electrical machines, and relates more particularly to electrical machines having at least one stator.
• An electric machine is a machine, also called a motor, which has at least one stator.
• the stator has teeth forming the coils.
• the supply of each of the coils allows the creation of a magnetic field in the stator, a rotor oriented along the field lines.
• these electrical machines are for example used in electrical systems such as supercharged electric compressors.
• these machines are used on the intake circuit to improve the efficiency of the vehicle, to overcome the latency of the conventional turbocharger at startup, or in the transient phases of the vehicle.
• this type of machine is a source of noise.
• the electromagnetic forces generated on the stator and the rotor induce micro-displacements at high frequency and in the audible range of the human ear, between 1000 and 20000Hz.
• the vibrations are transmitted throughout the structure of the machine, and propagate in the air and in the supports of the machine. If the noise from the machine to the support can be reduced by dampers, the noise intrinsic to the machine is more difficult to deal with.
• One solution to this noise is to reduce the effects of radial forces.
• the effects of radial forces are reduced, for example, by providing material recesses on the outer face of the stator, in the extension of the stator teeth.
• Such a solution allows a gain of deformation, to reduce the effects of radial forces on the piece in contact with the stator, 10%. This gain contributes to the partial reduction of noise, which is still audible by a human ear.
• the present invention therefore aims to overcome one or more of the disadvantages of the machines of the prior art by providing an electrical machine configured to limit noise.
• the present invention proposes an electric machine comprising at least one stator, the stator being formed of a body and teeth disposed on the internal face of the stator body, characterized in that the stator comprises at least one internal recess formed in the body of the stator.
• the recess extends longitudinally in the stator body parallel to a longitudinal axis of the stator.
• the internal recess to any geometric shape to limit the mechanical stresses on the stator.
• the width of the internal recess is smaller than the width of a stator tooth.
• the internal recess is a cylinder or an ellipse.
• the internal recess is disposed in the axis of a stator tooth.
• the internal recess is formed in the stator body at a sufficient distance from an inner face 221 of the stator body so as not to disturb the magnetic field.
• the stator comprises at least two external recesses formed on the outer face of the stator.
• the outer recess forms a groove oriented longitudinally along the longitudinal axis of the stator.
• the outer recess 25 is centered between two internal recesses 24, and overlaps, at each of its sides, an internal recess 24.
• the invention also relates to the use of the electric machine according to the invention in an electric supercharger for a motor vehicle.
• the invention also relates to an electric supercharger equipped with an electric machine according to the invention.
• FIG. 1 is a schematic representation of a sectional view of a device according to the invention
• FIG. 2 is a schematic representation of a detail of the device according to the invention.
• the present invention relates to an electric machine 1.
• the electric machine 1 comprises at least one stator 2, illustrated in FIGS. 1 and 2.
• the electric machine also comprises a rotor 3 disposed inside the stator 2. More precisely, the rotor 3 is disposed in a space 4 formed in the center of the stator 2.
• the electrical machine is a continuous or alternating current machine, synchronous or asynchronous or any type of electric machine of the same type.
• the electric motor is a variable reluctance motor (also called SRM machine for Switched Reluctance Motor according to English terminology).
• the stator comprises a body constituted by a stack of thin sheets forming a ring, also called a bundle of sheets, whose inner face is provided with notches open towards the inside to receive windings. phase which form a coil.
• the rotor is permanent magnets.
• the stator 2 is formed of at least one body 21. According to one embodiment of the invention, the stator is formed of several bodies. The stator is also formed of several teeth 22. The teeth 22 are disposed on the internal face 221 of the stator body delimiting the space 4 in which the rotor is located. The stator 2 has n teeth 22, n being between 4 and 12, and very preferably equal to 6. Around each of the teeth 22 is arranged a coil which thus forms the coils 23 of the stator. The supply of each of the coils 23 allows the creation of a magnetic field in the stator 2.
• the rotor 3 comprises rotor teeth 32 oriented along the field lines of the stator 2.
• the number of teeth of the rotor 3 is between 2 and 8, and preferably is equal to 4.
• the stator 2 comprises at least one internal recess 24.
• This internal recess 24 is formed in the body 21 itself of the stator.
• the internal recess 24 is formed in the body 21 of the stator 2, and extends longitudinally, along the longitudinal axis 31 of the stator, on at least a portion of the stator, in the body 21 of the stator 2. More specifically, the internal recess extends parallel to the axis 31 of the stator.
• the longitudinal axis 31 of the stator is defined as the axis 31 along which the stator extends, passing through the center of the stator, that is to say the axis 31 around which the stator is arranged.
• the internal recess 24 extends longitudinally over the entire length of the stator 2.
• the width L ei of the internal recess 24 is equal to or greater than the width L s of a tooth 22 of the stator 2.
• the width, recess and teeth of the stator is defined by the magnitude oriented along a plane P perpendicular to a plane passing through the radius R of the stator, as opposed to the height which is defined by the magnitude passing through the radius R of the stator.
• the recess 24 internal to all possible geometric shapes. More specifically, the recess 24 internal to all geometric shapes to limit the mechanical stresses on the stator 2. Indeed, it is the mechanical stresses that contribute to noise by promoting radial forces. The reduction of the effects of the efforts thus makes it possible to limit the noise nuisances.
• the internal recess 24 is a cylinder whose generatrix to any shape to limit the mechanical stresses on the stator. According to one embodiment of the invention, the internal recess 24 is round.
• the internal recess 24 is oval, its width L ei being greater than its height h ei .
• the internal recess 24 is square or rectangle.
• the internal recess 24 is rectangle or square, with rounded corners.
• the recess 24 internal to an ellipse shape more precisely the internal recess 24 is an elliptical cylinder whose width is greater than the height.
• the internal recess 24 is disposed in the axis of a tooth 22 of the stator. More specifically, the internal recess 24 is disposed in the portion of the body 21 of the stator 2 extending a tooth 22 of the stator.
• the internal recess 24 is formed in the stator body at a sufficient distance from the internal face 221 of the stator body so as not to disturb the magnetic field. More specifically, the smallest distance D ei between an edge of the internal recess 24 and the internal face 221 of the stator body is greater than or equal to the width of a stator tooth divided by two (L s / 2). Such an arrangement avoids modifying the magnetic field of the electric machine.
• the internal recess 24 is disposed in the body 21 of the stator 2 and at the periphery of the body 21. That is to say, the internal recess 24 is closer to the face external 222 of the stator 2 that of the internal face 221 of the stator 2.
• the outer face 222 of the stator 2 is the one which does not have a tooth 22 and which is disposed outside the stator 2 if it is considered that the internal face 221 of the stator defines a zone 4 of the stator 2 in which the rotor 3 is arranged.
• the stator 2 comprises a number of recesses 24 identical to the number of teeth 22 of the stator.
• the stator has six internal recesses 24.
• the stator 2 comprises at least one external recess 25 formed on the external face of the stator, illustrated in FIG.
• This outer recess forms a groove oriented along the axis 31 of the rotor 3.
• the outer recess 25 is offset from the teeth 22 of the stator.
• the outer recess is centered between two internal recesses.
• the width of the outer recess 25 is such that it overlaps, at each of its sides, an internal recess 24.
• the machine comprises two external recesses 25, the distance D ex between two external recesses being less than the width L ei of an internal recess 24.
• the stator 2 thus comprises an alternation of internal recesses 24 and external recesses 25.
• the depth of the outer recess is between 0 and a remaining thickness of the stator body greater than or equal to the width of a stator tooth divided by two (L s / 2).
• remaining thickness means the remaining thickness between the bottom of the recess and the internal face 221 of the stator or the beginning of a tooth 22 of the stator.
• the stator 2 comprises a number of external recesses 25 identical to the number of teeth 22 of the stator.
• the stator has six external recesses.
• Such a stator 2 according to the invention allows a gain of 50% in terms of mechanical stresses.
• the invention also relates to the use of such a machine according to the invention in an electric supercharger for a motor vehicle.
• the invention also relates to an electric supercharger equipped with such a machine 1 according to the invention. More specifically, the invention also relates to an electric compressor equipped with a variable-reluctance motor according to the invention.
• This electric supercharger compressor for a motor vehicle comprises a compression wheel and an electric machine according to the invention for driving the compression wheel in rotation.

Applications Claiming Priority (2)

Publications (1)

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ID=52627297

Family Applications (1)

Country Status (6)

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• 2014
  • 2014-10-20 FR FR1460049A patent/FR3029711B1/fr active Active
• 2015
  • 2015-10-19 JP JP2017521238A patent/JP2017531993A/ja active Pending
  • 2015-10-19 US US15/519,986 patent/US20170373546A1/en not_active Abandoned
  • 2015-10-19 CN CN201580068723.8A patent/CN107112817A/zh active Pending
  • 2015-10-19 WO PCT/FR2015/052798 patent/WO2016062953A1/fr active Application Filing
  • 2015-10-19 EP EP15797122.7A patent/EP3210281A1/de not_active Withdrawn

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