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
  • H02K1/27—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
  • H02K1/2773—Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM] having a flux concentration effect consisting of tangentially magnetized radial magnets
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K1/00—Details of the magnetic circuit
  • H02K1/02—Details of the magnetic circuit characterised by the magnetic material

Definitions

• the present invention relates to a permanent magnet rotor for a rotating electrical machine.
• the invention also relates to a rotary electric machine comprising a rotor of this type, in particular for applications as an electric traction motor in electric and hybrid motor vehicles.
• “Mild-hybrid” applications generally relate to electrical machines in the order of 8 to 15 W t for example, an electric motor mounted on the front of an engine and coupled thereto by a drive belt. It is possible with such an electric motor to reduce the displacement of the engine (“engine do nsizing" in English terminology) by providing a power assisted torque that provides extra power, especially during rework. In addition, a low speed traction, for example in urban environment, can also be provided by the same electric motor.
• “Full-hybrid” type applications generally concern motors from 30 to 50 kW for series and / or parallel type architectures with a more advanced integration level of the electric motor or motors in the vehicle's power train.
• Neodymium-Iron-Bore Neodymium-Iron-Bore
• SmFe Samarium- Iron
• SmCo Samarium-Cobalt
• ELECTRIC EQUIPMENT MOTOR it is proposed to give the magnets a substantially trapezoidal shape in the direction of the axis of the rotor, so as to maximize the volume of ferrite in the rotor and maximize the electrical efficiency of the machine.
• the object of the present invention is therefore to optimize the volume of the magnets of a rotor in order to maximize the efficiency of its machine in the open perspective by teaching its previous aforementioned request from the applicant company, while at the same time overcoming certain disadvantages. of its anterior rotor structure. It relates specifically to a rotary electric machine rotor comprising a plurality of alternating North poles and South poles and formed from a plurality of permanent magnets arranged in first recesses.
• first recesses extend axially and are regularly distributed between a circumferential portion and a central portion of the magnetic mass of the rotor so as to define a plurality of circumferential polar sections.
• the permanent magnets of the rotor type in question each have a first portion close to the circumferential portion adjacent to a second portion near the central portion, the first portion having a first rectangular radial section of a first predetermined width in a second portion. circumferential direction and the second portion having a second rectangular radial section of a second predetermined width in a circumferential direction, the second width being smaller than the first width.
• the rotor further comprises a plurality of second recesses extending axially and each arranged between two consecutive copies of the magnets at the second part.
• These second recesses advantageously delimit pairs of ribs extending axially and radially maintaining the polar sections.
• these second recesses each preferably have a substantially triangular radial section.
• the magnets are each advantageously in the form of a one-piece assembly, preferably consisting of molded ferrite.
• the first part is formed of a first magnetic bar and the second part is formed of a second magnetic bar.
• the first and second magnetized bars advantageously consist of ferrite, but, alternatively, the first magnetic bar is very advantageously made of ferrite and the second magnetic bar is made of a material comprising at least one rare earth, preferably neodymium.
• circumferential portion is radially open, at least partially, facing the permanent magnets.
• the invention also relates to a rotating electrical machine which comprises a rotor having the above characteristics.
• Figure 1 shows a simplified radial sectional view of a permanent magnet rotor seion the invention.
• FIG. 1 The simplified radial section of a rotor 1 with permanent magnets in a preferred embodiment of the invention, shown in FIG. 1, clearly shows the arrangement in the magnetic mass 2 of the permanent magnets 3 in first recesses 4 regularly distributed between a circumferential portion 5 and a central portion 6 so as to form a plurality of North N poles and South poles S alternate.
• a concrete embodiment of a machine comprising such a rotor is for example a motor / generator 8 to 15 KW for applications in motor vehicles of the type called "mild-hybrid".
• this machine In its engine mode of operation, this machine can be designed for starting the engine, assisting the engine as well as for the low-speed electric traction of the vehicle.
• a rotor 1 having ten permanent magnets 3 rotates inside a stator (not shown) having a plurality of notches.
• the stator and the rotor 1 are made conventionally with packets of metal sheets forming magnetic masses 2,
• the notches of the stator are provided to receive stator windings (not shown) and form between them a plurality of stator teeth.
• the notches are intended to house concentrated windings, wound on large teeth, or windings distributed.
• stator windings are traversed by a stator current and create a rotating magnetic field driving the rotor 1.
• the engine torque supplied depends in particular on the intensity of the stator current and the magnetic flux in the rotor 1,
• the volume of the ferrite magnets must therefore be maximized.
• the invention therefore proposes to give a stepped shape to the magnets 3.
• the magnets 3 occupy an important volume of the magnetic mass 2 of the rotor 1 both in the vicinity of the circumferential portion 5 and in the vicinity of the central portion 8, as shown in FIG.
• This stepped form is advantageously formed by magnets 3 each having a first portion 7 close to the circumferential portion 5 of the rotor 1 adjacent to a second portion 8 close to the central portion 6.
• the first part 7 is formed by a first magnetic bar having a first rectangular cross section and the second part 8 is formed by a second magnetic bar, juxtaposed radially to the first towards the central portion 6.
• Magnetic bars 7, 8 of rectangular section are standard industrial supplies that are manufactured in large quantities in various sizes and in various materials, depending on the required remanent magnetization, by the industry.
• the manufacture of the rotor 1 thus benefits from the economies of scale resulting from the very large production of its main element.
• the second magnet bar 8, being the closest to the central portion 6, is of a second width L2 (in a circumferential direction) smaller than a first width L1 of the first magnet bar 7,
• second recesses 9 are arranged between the magnets 3 at the second part 8 thereof.
• these second recesses 9 contribute to the control of the magnetic field in the rotor 1.
• the first recesses 4 of the rotor 1 according to the invention preferably comprise openings 12 towards the periphery of the magnetic mass 2.
• openings have the effect of increasing the reluctance of these parts of the magnetic circuit, and thus of limiting the leakage flux of the magnets 3, while contributing to the reduction in the mass of the circumferential portion 5 of the rotor 1, which allows to increase the mass of the magnets 3 while remaining within the limits of the mechanical stresses supported by the ribs 10.
• the first magnet bar 7, the largest, is advantageously made of ferrite, while the second magnetic bar 8, less bulky, can be of rare earth type, including neodymium, without a great impact on the cost.
• first and second magnet bars 7, 8 are both made of ferrite for less demanding applications.
• the magnets 3 are in the form of a one-piece molded ferrite assembly.
• the stepped form of magnets 3 according to the invention allows, in cooperation with the triangular shape of the second recesses 9, to create the pairs of ribs 10 essential for strengthening the mechanical strength of the rotor 1.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Permanent Field Magnets Of Synchronous Machinery (AREA)
• Iron Core Of Rotating Electric Machines (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=49212799

Family Applications (1)

Country Status (6)

Families Citing this family (6)

Citations (1)

Family Cites Families (14)

• 2013
  • 2013-06-05 FR FR1355146A patent/FR3006824B1/fr not_active Expired - Fee Related
• 2014
  • 2014-06-02 EP EP14736880.7A patent/EP3005532A1/de not_active Withdrawn
  • 2014-06-02 US US14/894,759 patent/US20160105059A1/en not_active Abandoned
  • 2014-06-02 WO PCT/FR2014/051294 patent/WO2014195613A1/fr active Application Filing
  • 2014-06-02 CN CN201480032081.1A patent/CN105264747A/zh active Pending
  • 2014-06-02 JP JP2016517653A patent/JP2016521113A/ja active Pending

Patent Citations (1)

Non-Patent Citations (1)

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