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
  • H02K1/24—Rotor cores with salient poles ; Variable reluctance rotors
  • H02K1/246—Variable reluctance rotors
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K5/00—Casings; Enclosures; Supports
  • H02K5/24—Casings; Enclosures; Supports specially adapted for suppression or reduction of noise or vibrations

Definitions

• the present invention relates to an electric machine, and more particularly to an electric motor with variable reluctance or permanent magnets for application in a motor vehicle, in particular for an electric supercharger.
• the invention also relates to an electric supercharger compressor for a motor vehicle, comprising such a variable reluctance motor or permanent magnets.
• Such an electric supercharger is conventionally implemented in the air intake line of a combustion engine of a motor vehicle, upstream or downstream of a turbocharger.
• a compressor can be implemented on a recirculation line of the exhaust gas of the internal combustion engine.
• the electric supercharger conventionally comprises a wheel for compressing the air entering the compressor and a variable-reluctance electric machine or permanent magnets for driving the wheel in rotation.
• the electric supercharger powered by an electric motor, has a very short response time. This makes it possible to increase the torque of the internal combustion engine at low speed, to compensate for the turbocharger response time and to improve the accelerations of the motor vehicle on which is mounted the internal combustion engine equipped with the electric supercharger.
• the electric machine and for example the variable reluctance motor or permanent magnets used in such an electric supercharger is subjected to large amplitude vibrations due to variations in flux and electromagnetic forces, which are detrimental to comfort. of the driver of the motor vehicle.
• the object of the present invention is to provide an electric machine, and for example an electric motor with variable reluctance or permanent magnets, improved for automotive application, in particular for electric supercharging compressor, not having at least some of the aforementioned drawbacks.
• the invention proposes an electric machine and in particular an electric motor with variable reluctance or permanent magnets for application in a motor vehicle, in particular for an electric supercharger for a motor vehicle, comprising a rotor and a stator provided with radial teeth, at least one of the rotor and the stator having a cross section which can be divided into angular sectors of the same angle in the center and including a single radial tooth, at least one of said angular sectors being different from at least one of the other said angular sectors.
• the noise emitted by the machine is shifted to the lower frequencies. Indeed, it limits the noisy phenomena related to the rotation of the rotor relative to the stator which have a frequency equal to a multiple of the rotor rotation frequency.
• the overall noise emitted by the machine has higher harmonics for lower frequencies which are less uncomfortable for users, or that may be inaudible to some users.
• the comfort of use of the engine is improved.
• each of said angular sectors is different from the other said angular sectors
• stator has a cross-section with symmetry of revolution
• the rotor has a symmetrical cross section
• the rotor and the stator have a cross-section which can be divided into angular sectors of same angle in the center and including a single radial tooth, at least one of said angular sectors of each of the rotor and of the stator being different from at least one other said angular sectors of the rotor, respectively of the stator;
• the center of gravity of the rotor is located on its axis of rotation
• At least one of the teeth of at least one of the rotor and the stator is different from the other teeth of the same one of the rotor and the stator;
• the tooth is wider than the other teeth.
• the invention relates to an electric supercharger compressor for a motor vehicle, comprising a compression wheel and an electric machine, for example an electric motor with variable reluctance or permanent magnets, as described above in all its combinations, to drive the compression wheel in rotation.
• FIG. 1 shows a cross section of an electric machine of a supercharger for a motor vehicle
• FIG. 1 is an enlargement of the rotor of the electric machine shown in Figure 1.
• an electrical machine 10 essentially comprises a rotor 12 and a stator 14.
• the rotor 12 is here mounted radially inside the stator 14.
• the rotor 12 and the stator 14 are made of ferromagnetic metallic material.
• the stator does not comprise here winding oriented in the longitudinal direction of the electric machine 10.
• the rotor 12 has teeth 16 (hereinafter radially rotor teeth 16), oriented radially outward, here four in number .
• the rotor teeth 16 are equidistributed angularly.
• the stator 14 has for its teeth 18 (hereinafter statoric teeth 18) also radial, oriented in the opposite direction to the teeth 16 of the rotor 12.
• stator teeth 18 are more numerous than the rotor teeth 16.
• the stator 14 has six statoric teeth 18.
• the statoric teeth 18 are angularly distributed.
• Each of the stator teeth 18 is surrounded by a winding 20 or phase winding.
• two opposite (or symmetrical) coils are electrically powered, they form electromagnets and cause the rotor 12 to rotate to align the rotor teeth 16 with the stator teeth 18 surrounded by the electrically powered coils.
• the rotor 12 is rotated, the torque being produced by the tendency of the rotor to position itself so that the reluctance between a stator tooth and a rotor tooth is at a minimum. that is, the gap between these rotor and stator teeth is minimal.
• the rotor 12 has a cross section that can be divided into four angular sectors S1-S4 of the same angle in the center, each angular sector S1 -S4 including a single rotor tooth 16.
• Each of the angular sectors S1 -S4 here corresponds to a central angle of 90 °.
• Each of said angular sectors S1-S4 is here different from each of the other angular sectors S1-S4. This allows to move to the lower frequencies, the noise emissions of the electrical machine, and for example the variable reluctance motor or permanent magnets, 10, especially in a frequency range inaudible to at least some users.
• a noisy phenomenon, related to the rotation of the rotor 12 is limited and has a frequency greater than that of the rotation of the rotor 12, in particular equal to a multiple of the rotor rotation frequency 12.
• the rotor teeth I 6 1 -I 6 4 are connected, in cross section, by distinct curves.
• regular curves which are easier to make, are preferred.
• the curve does not form, for example, sharp stops, these being fragile.
• the curve does not form, preferably, notches on the radially outer surface of the rotor 12. In particular, the curve does not form wedge angles, which can create rotor failure primers 12.
• the first and second rotor teeth I 6 1 , 16 2 are connected here, in cross-section, by a right-hand section 22.
• rounded corners have been formed between the section 22 and the profile 24i, 24 2 of the first and second rotor teeth 16 1 , 16 2 , to prevent the formation of a fracture primer at these angles.
• the second and third rotor teeth 16 2 , 163 are connected, in cross section, by a circular arc 26, open radially inwards.
• rounded corners were formed between the arc 26 and the profile 24 2 , 24 3 of the second and third rotor teeth 162, 163 to prevent the formation of a fracture primer at these angles.
• the third and fourth rotor teeth 163, 16 4 are connected, in cross-section, by a straight section 28, longer than the section of right 22 between the first and second rotor teeth 16i, I 6 2 .
• rounded corners have been formed between the circular arc 26 and the profile 24 2 , 24 3 of the second and third rotor teeth 16 2 , 163 so as to avoid the formation of a fracture primer at these levels. angles.
• first and fourth rotor teeth I 6 1 , 16 4 are connected, in cross section, by a circular arc 30 open radially outwards.
• the profile of the first and fourth rotor teeth I 6 1 , 16 4 extend in the extension of the arc 30.
• a rotor tooth 16 may be wider than the others, better still, each rotor tooth 16 may have a width different from the other rotor teeth 16.
• the rotor 12 is arranged to maintain the center of gravity of the rotor 12 located on its axis of rotation, especially at its geometric center. This avoids the unbalance effects that could cause premature wear of the O-machine.
• the rotor 12 and the stator 14 have cavities 32, 34, 36, respectively. These cavities 32, 34, 36 make it possible to reduce the rigidity of the rotor 12 and / or of the stator 14, which makes it possible to limit the noise emitted by the machine, and for example the variable reluctance motor or permanent magnets and / or lower the emission frequencies of these noises.
• these cavities 32, 34 on the torque exerted on the rotor 12 are formed in the rotor 16 and stator 18, respectively, and open only at the two faces end of the rotor 12 and the stator 14.
• the stator 14 also has on its radially outer surface cavities 36 which extend substantially in the longitudinal direction of the electrical machine 10 and which open at the two end faces of the stator 14 and on its radially outer surface.
• the stator teeth 18 also present here, in cross-section, a chamfer 38.
• the profile of the stator teeth 18 here have a base portion with two parallel sides, connected to the top of the stator teeth 18 by inclined surfaces relative to the two parallel sides of the base part.
• the angle of inclination of these surfaces can in particular be greater than 1 °, more preferably greater than 3 °, and less than 10 °, more preferably less than 7 °.
• chamfers 38 make it possible to limit the amplitude of the variations of magnetic flux when the rotor teeth 16 align with the stator teeth 18. Indeed, because of the presence of the chamfers 38, this variation of the magnetic flux is achieved less suddenly, which limits the noise emitted by the electric machine 10.
• chamfers may be provided only on the rotor 12 or both on the rotor 12 and on the stator 14.
• An electric machine and for example a variable reluctance motor or permanent magnet, as just described can be implemented in many applications in a motor vehicle. In particular, it can be implemented for a traction motor system.
• the electric machine and for example the variable reluctance motor or permanent magnets as just described can be implemented in an electric supercharger for a motor vehicle, comprising a wheel of compression driven in rotation by the rotation of the motor rotor.
• stator 14 can be received in a housing of the machine leaving empty spaces (or gaps) between the stator 14 and the housing, the empty spaces extending substantially in a longitudinal direction of the electric machine.
• the stator and the housing of the machine then preferably define linear contact areas. These empty spaces between the stator and the housing of the machine can limit the noise radiated by the machine.
• the stator 14 may have a cross section of generally polygonal shape, possibly having one or more cuts formed by the cavity or cavities 28 opening on the radially outer surface of the stator 14 and, preferably, rounded corners intended for in contact with the housing of the machine, which housing of the machine is preferably generally circular in cross section.
• stator has a cross section with symmetry of revolution.
• the stator 14 may have a cross-section that can be divided into angular sectors of same angle in the center and including a single radial tooth, at least one of said angular sectors being different from at least one of said other angular sectors, preferably each angular sector being different from the other angular sectors.
• This also makes it possible to move the noise emissions of the electrical machine, and for example of the variable-reluctance motor or permanent magnets, to the higher frequencies, especially in a frequency range that is inaudible to at least some users.
• the rotor may then have a cross-section with symmetry of revolution.
• the rotor 12 and the stator 14 both have a cross-section which can be divided into angular sectors of same angle at the center and including a single radial tooth, at least one of said angular sectors of each of the rotor and the stator, being different from at least one of said other angular sectors of the rotor, respectively of the stator.
• each of the angular sectors of the rotor and the stator are different from the other angular sectors of the rotor and the stator, respectively.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Iron Core Of Rotating Electric Machines (AREA)
• Synchronous Machinery (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)

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Family Cites Families (5)

• 2014
  • 2014-11-20 FR FR1461265A patent/FR3029027B1/fr active Active
• 2015
  • 2015-11-18 EP EP15805592.1A patent/EP3221949A2/de not_active Withdrawn
  • 2015-11-18 WO PCT/FR2015/053118 patent/WO2016079427A2/fr active Application Filing

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