Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K3/00—Details of windings
  • H02K3/46—Fastening of windings on the stator or rotor structure
  • H02K3/48—Fastening of windings on the stator or rotor structure in slots
  • H02K3/487—Slot-closing devices
  • H02K3/493—Slot-closing devices magnetic
• • 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
  • H02K1/16—Stator cores with slots for windings
• • 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
  • H02K1/2706—Inner rotors
  • H02K1/272—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis
  • H02K1/274—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets
  • H02K1/2753—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets the rotor consisting of magnets or groups of magnets arranged with alternating polarity
  • H02K1/276—Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM]
  • H02K1/2766—Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM] having a flux concentration effect
• • 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
  • H02K21/14—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets rotating within the armatures

Definitions

• the present invention relates to a rotating electrical machine with a closed-slot stator and more particularly to a synchronous-electric machine assisted by a rotating electric machine with a stator with closed notches and more particularly a reluctant electric synchronous machine assisted by permanent magnets. permanent magnets.
• the electric machine comprises an open-slot stator which is closed by suitable means so that the gap between the outer surface of the rotor and the inner surface of the stator is substantially constant.
• such an electric machine comprises a stator and a rotor arranged along the same axis one in the other.
• the rotor is formed of a rotor body with a stack of sheets placed on a rotor shaft. These sheets include housings for permanent magnets and perforations to create flux barriers for radially directing the magnetic flux of the magnets to the stator.
• This rotor is generally housed inside a stator which carries electrical windings to generate a magnetic field for rotating the rotor.
• the stator is annular in shape and includes a plurality of radial notches open towards the rotor and extending all the way around the stator.
• notches are provided to receive armature coils which are introduced into the stator by the open face of the notches and are fixed thereto by any known means.
• torque ripple is important in this type of reluctant synchro machine assisted by permanent magnets. This can cause jerks and vibrations in the rotor causing discomfort in use of this machine.
• WO201 6/188764 discloses an electric machine with a closed slot stator which reduces torque ripple and acoustic noise.
• this solution imposes in particular an implementation of unconventional manufacturing due to the notches closed.
• the present invention relates to an electric machine comprising a rotor and a stator having an inner wall facing the rotor, said stator carrying a multiplicity of radial notches arranged circumferentially along said stator, said notches having openings opening into said internal wall.
• said openings are closed by closure means so as to form a multiplicity of closed notches.
• the notches of the electric machine may extend longitudinally along the axis of the stator.
• Said closure means may comprise a wedge of magnetic material of dimensions corresponding to said openings so as to close the notches.
• the spacers may have a thickness such that they are flush with the surface of the inner wall of the stator.
• Wedges can be crimped, welded, or glued into openings.
• the sealing means may comprise a cylinder of magnetic material disposed on the inner wall of the stator so as to close the notches.
• Said cylinder can be fixed by shrinking in the inner wall of the stator.
• FIGS. 1a and 1b which are a schematic cross-sectional view of electrical machines according to the prior art
• FIGS. 1c and 1d which are a schematic view in cross section of the stator of the machine according to the invention.
• FIG. 2a which is a graph illustrating the evolution of the constant current torque as a function of the electric position of the rotor for electrical machines of the prior art and for two electrical machines according to the invention
• FIG. 2b which is a graph giving the amplitude of the harmonic torque (N.m) for the four embodiments described in FIGS. 1a, 1b, 1c and 1d.
• FIGS. 1a, 1b, 1c and 1d show in partial section a rotating electrical machine, here a synchronous-reluctant electric machine assisted by permanent magnets, comprising a rotor 1 and a stator 2 nested one in the other by being coaxial.
• the construction of the rotor comprises, in a known manner and in particular described in WO201 6/188764, a preferably magnetic shaft, on which is placed a stack of identical flat ferromagnetic sheets, which are assembled to each other by any known means.
• Figures 1 to 1 d show at least partially this type of rotor.
• the circular-shaped sheets comprise a central bore through which the rotor shaft passes and a plurality of axial recesses 20 which pass through the sheets from one side to the other.
• the rotor comprises at least two series of rectangular axial recesses 20, radially arranged one above the other, the rectangular axial recesses 20 being distributed circumferentially on the rotor 1.
• Another series of recesses 40 consists of inclined radial direction perforations, which extend said housing to the vicinity of the edge of the sheets.
• a stator 2 according to the prior art, partially shown in FIGS. 1a, 1b, comprises an annular ring with an internal wall 3 whose inside diameter is designed to receive the rotor 1 with a space necessary to make a gap 4.
• This ring comprises a multiplicity of holes 5, here of oblong section, which form notches for receiving the armature coils.
• these bores extend axially all along the stator by being arranged radially on the ring while being placed circumferentially at a distance from each other by a distance D.
• Figure 1 depicts a closed volume that forms a closed notch for receiving the armature coil.
• the wall 3 is a continuous wall and the gap 4 is almost constant between the rotor and the stator and that over the entire circumference.
• FIG. 1b describes the conventional configuration of a stator with open notches at the bottom of said notches by openings 6. These openings allow the winding of the armatures, in particular mechanically, whereas in the case of closed notches the windings of induced must be made manually.
• the object of the present invention is to combine both the benefit of the closed notches with a stator with open notches that reduce the cost of production by the possibility of automated winding and obtain a better winding coefficient of the order of 0.6.
• the openings 6 of the stator are closed by suitable means, such as plates or wedges of magnetic material of the width of the openings 6 and the length corresponding to the length of the stator.
• suitable means such as plates or wedges of magnetic material of the width of the openings 6 and the length corresponding to the length of the stator.
• Figure 1c illustrates this embodiment by showing in section the closure means 7 shaped wedge, or plate.
• These sealing means may be crimped, glued, welded, or maintained by any means available to the skilled person.
• These wedges advantageously have a thickness such that they are flush with the surface of the inner wall of the stator.
• the gap is substantially constant over the entire circumference, and the inner surface 3 of the stator is substantially smooth.
• FIG. 1 d describes another embodiment of said means for closing the open notches 5.
• a cylinder 8 of diameter and length respectively corresponding to the internal surface and to the length of the stator is placed on the inner surface 3 of the open stator.
• the gap 4 is constituted by the outer surface of the rotor and the inner surface of the hoop 8.
• the cylinder 8, or hoop is made of a magnetic material.
• the cylinder may be fixed on the internal surface 3 of the stator by any means known to those skilled in the art, in particular by shrinking, gluing, welding.
• the cylinder 8 being of small thickness relative to its diameter, the hooping is a means of well fitting, hence the name "fret" for said means for closing the openings of the stator slots.
• the synchro-reluctant machine has significantly improved performance.
• FIG. 2a is a graph with curves illustrating the torque of the electric machine (in Nm) relative to the electrical position of the rotor (in °) for a constant current, for the four embodiments of the stator: closed notches E, notches open O, notches closed by wedges C, notches closed by fretting F.
• FIG. 2b gives the level of the harmonic content of the instantaneous torque. Note that in the case of the stator with notches open, the rank 36, corresponding to the number of teeth of the stator, predominates. In the other configurations, the amplitude of the harmonics tends to decrease while increasing in frequency. This is interesting, especially in terms of losses iron, because it does not come to excite harmonics of high rank that could generate more losses (the losses in the iron being proportional to /, f 2 and ' 2 ).
• the posterior closure does not introduce significant changes in the electromagnetic performance compared to the closed slot structure.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Iron Core Of Rotating Electric Machines (AREA)
• Permanent Field Magnets Of Synchronous Machinery (AREA)
• Manufacture Of Motors, Generators (AREA)
• Synchronous Machinery (AREA)
• Permanent Magnet Type Synchronous Machine (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=58632491

Family Applications (1)

Country Status (6)

Family Cites Families (9)

• 2017
  • 2017-02-24 FR FR1751523A patent/FR3063398A1/fr active Pending
• 2018
  • 2018-02-16 EP EP18704988.7A patent/EP3586425A1/fr not_active Withdrawn
  • 2018-02-16 JP JP2019545799A patent/JP2020509728A/ja active Pending
  • 2018-02-16 WO PCT/EP2018/053884 patent/WO2018153783A1/fr unknown
  • 2018-02-16 US US16/487,486 patent/US20200059125A1/en not_active Abandoned
  • 2018-02-16 CN CN201880013681.1A patent/CN110582925A/zh active Pending

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