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
  • H02K1/28—Means for mounting or fastening rotating magnetic parts on to, or to, the rotor structures
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K15/00—Processes or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
  • H02K15/16—Centring rotors within the stators

Definitions

• the present invention relates to the field of electrical machines, and relates more particularly to an electrical machine comprising at least one stator and a rotor.
• An electric machine has a rotor and a stator.
• the rotor is mounted on a tree.
• the stator has teeth around which the coils are wound. The supply of each of the coils allows the creation of a magnetic field in the stator, the rotor, also having teeth, is oriented along the field lines.
• An example of an electric motor having a stator and a rotor is the variable reluctance motor.
• these machines are generally 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.
• the air gap between the stator and rotor teeth is very important in terms of constancy. Indeed, the greater the variation of this gap on a lathe is important, the more the effect is negative on the performance of the machine.
• This air gap is due to the game which is added to it.
• the game is the result of all the defects of each piece and their assembly.
• this game comes from the fact that the rotor is mounted tight on the shaft. A lack of concentricity between the inside diameter of the rotor and outside the shaft adds play to the gap. This causes a decrease in the performance of the electric motor.
• the present invention therefore aims to overcome one or more of the disadvantages of the motor of the prior art by providing an electrical machine configured to limit variations in the gap between the rotor and the stator.
• the present invention proposes an electric machine comprising a rotor, the rotor being tightly mounted on a rotatable shaft, a holding material being positioned between the rotor and the shaft.
• this holding material makes it possible to eliminate the concentricity defects between the inside diameter of the rotor and the outside of the shaft, which limits the clearance at the gap.
• this holding material makes it possible to create a thermal barrier between the rotor and the shaft and thus to other parts to which the shaft is connected.
• the holding material is a material injected between an inner surface of the rotor and an outer surface of the shaft.
• the holding material is resin metal or plastic.
• the inner surface of the rotor comprises counterforms.
• the outer surface of the shaft comprises counterforms.
• the counterforms are all forms allowing the transmission of the forces of the rotor on the shaft.
• the counterforms transmit the force of the rotor on the shaft allowing better adhesion between the holding material and the shaft.
• the invention also relates to a method for obtaining an electric machine according to the invention, comprising the steps of:
• overmolding is performed by injection of holding material according to the invention between the inner surface of the opening of the rotor and the outer surface of the shaft.
• 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 an elevational view of a device according to the invention
• FIG. 2 is a schematic representation of an element of the device according to the invention.
• FIG. 3 is a schematic representation of another element of the device according to the invention.
• FIG. 4 is a schematic representation of another element of the device according to the invention.
• FIG. 5 is a schematic representation of a sectional view of a device according to the invention.
• FIG. 6 is a schematic representation of a sectional view of an electric machine according to the invention.
• the present invention relates to an electric machine 1 illustrated in FIGS. 1 and 6.
• the machine 1 comprises at least one stator 2 and one rotor 3.
• the rotor 3 is disposed inside the stator 2. More precisely, the rotor 3 is disposed in a space 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 electrical machine is a variable reluctance motor (also called SRM machine for Switched Reluctance Motor according to English terminology).
• the electric machine is a permanent magnet motor.
• the stator 2 is formed of at least one body.
• the stator 2 is formed of several bodies.
• the stator is also made up of several teeth.
• the teeth are disposed on the inner face of the stator body defining the space in which the rotor is located.
• the stator has n teeth, n being between 4 and 12, and very preferably equal to 6.
• Around each of the teeth is disposed a winding which thus forms the stator coils. The supply of each of the coils allows the creation of a magnetic field in the stator.
• the rotor 3 comprises rotor teeth 32.
• the number of teeth of the rotor 3 is between 2 and 8, and preferably is equal to 4.
• the rotor comprises at its center a longitudinal opening 31. This opening 31 is traversed by a shaft 5 mounted in rotation.
• the shaft 5, illustrated in FIGS. 1, 4 and 5 is connected to the rotor 3 of the electric machine which allows the rotation drive of the shaft 5, and an end of the shaft 5 is connected to for example a wheel, not shown, of an electric compressor.
• the rotor 3 is thus mounted tight on the shaft 5. It is the rotor 3 which allows the shaft 5 to be rotated.
• a holding material 6, illustrated in FIGS. 1, 3 and 5 is disposed between the rotor 3 and the shaft 5. More specifically, the holding material 6 is disposed between the inner surface of the aperture 31 of the rotor and the outer surface of the shaft 5.
• Fig. 3 shows the insulated holding material 6, the rotor and the shaft. This state does not exist and is only a representation to allow a better understanding of the invention.
• the holding material 6 is injected between the inner surface of the opening 31 of the rotor and the outer surface of the shaft 5.
• this holding material 6 makes it possible to eliminate the concentricity defects between the inside diameter of the rotor 3 and the outside of the shaft 5, which limits the clearance at the air gap 4, illustrated in FIG. 6, between the teeth. stator and rotor and thus limits the variation of this gap.
• this holding material 6 makes it possible to create a thermal barrier between the rotor and the shaft 5. This thermal barrier thus makes it possible to limit heat transfer to other parts to which the shaft is connected, and for example the guiding parts in rotation.
• the holding material 6 is resin
• the holding material 6 is metal
• the holding material 6 is plastic.
• the holding material 6 is a seal, and for example a liquid seal.
• the inner surface of the rotor 3 comprises counter-forms 61.
• the counter-forms 61 are all forms allowing the transmission of the forces of the shaft 5 on the rotor 3.
• the counter-forms 61 of the rotor 3 are longitudinal ribs oriented along the longitudinal axis X of the shaft 5, rectilinear or not.
• the counter-forms 61 of the rotor 3 are longitudinal grooves oriented along the longitudinal axis X of the shaft 5, rectilinear or not.
• the counter-forms 61 transmit the force of the rotor 3 on the shaft 5 by allowing better adhesion between the holding material and the shaft. Indeed, when the holding material 6 is injected, it fills all the spaces between the outer surface of the shaft and the inner surface of the rotor. In this way, when the rotor and the holding material rotate, the better adhesion of the holding material with the shaft via the counter-forms 61 ensures a total transmission of the forces of the rotor 3 on the shaft 5.
• the outer surface of the shaft 5 also comprises counter-forms 51.
• counterforms 51 are all forms allowing the transmission of the forces of the rotor 3 on the shaft 5.
• the counter-forms 51 of the shaft 5 are longitudinal ribs oriented along the longitudinal axis X of the shaft 5, rectilinear or not.
• the counter-forms 51 of the shaft 5 are longitudinal grooves oriented along the longitudinal axis X of the shaft 5, rectilinear or not.
• the counter-forms 51 of the shaft 5 have the same role and the same effects as the counter-forms 61 of the rotor.
• the rotor 3 and the shaft 5 comprise counter-forms 51, 61 as described above.
• the combination of the counterforms 61 of the rotor 3 and counterforms 51 of the shaft 5 makes it possible to increase more significantly the adhesion of the holding material 6 to the shaft and the rotor, and thus to to improve more significantly the transmission of the forces of the rotor 3 on the shaft 5, compared to the case where only the shaft 5 or the rotor 3 has counterforms.
• the method according to the invention making it possible to obtain a machine according to the invention, consists first of all in positioning the rotor 3 with respect to the shaft 5. The positioning being carried out with respect to a reference pre-defined on the 5. The shaft between the shaft 5 and the rotor 3 is then formed by overmolding the rotor 3 and the shaft 5. More precisely, the overmolding is performed by injection of the holding material 6 according to the invention between the inner surface of the opening 31 of the rotor and the outer surface of the shaft 5.
• This method according to the invention makes it possible to obtain an electric machine 1 whose shaft 5 and rotor 3 are overmolded.
• the invention also relates to the use of such a machine 1 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.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Supercharger (AREA)

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Publications (1)

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Country Status (3)

Family Cites Families (5)

• 2014
  • 2014-11-19 FR FR1461192A patent/FR3028688B1/fr active Active
• 2015
  • 2015-11-18 WO PCT/FR2015/053117 patent/WO2016079426A2/fr not_active Ceased
  • 2015-11-18 EP EP15804172.3A patent/EP3221950A2/de not_active Withdrawn

Non-Patent Citations (2)

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