Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
  • H02K11/20—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for measuring, monitoring, testing, protecting or switching
  • H02K11/25—Devices for sensing temperature, or actuated thereby
• • 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
  • H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
  • H02K11/20—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for measuring, monitoring, testing, protecting or switching
  • H02K11/21—Devices for sensing speed or position, or actuated thereby
• • 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

Definitions

• TITLE Rotor for electric motor equipped with rod sensor
• the present invention relates to a rotor for an electric motor.
• the invention also relates to an electric motor comprising such a rotor.
• current electric motors include a rotor integral with a shaft and a stator which surrounds the rotor.
• the stator is mounted in a housing which has bearings for the rotational mounting of the shaft.
• the rotor comprises a body formed by a stack of sheets or pole wheels (claw pole) held in the form of a package by means of a suitable fixing system.
• the rotor body has internal cavities housing permanent magnets.
• the stator comprises a body formed by a stack of sheets forming a ring, the inner face of which is provided with teeth delimiting in pairs a plurality of notches open towards the interior of the stator body and intended to receive phase windings.
• phase windings pass through the notches of the stator body and form buns projecting on either side of the stator body.
• the phase windings can for example consist of a plurality of U-shaped conductor segments, the free ends of two adjacent segments being connected together by welding.
• the pack of sheets is clamped axially between a front flange and a rear flange mounted coaxially with the shaft.
• Each flange has the overall shape of a disc extending in a radial plane perpendicular to the axis of the shaft.
• Each flange has a central orifice for coaxial mounting on the shaft and several through holes intended to receive bolts axially passing through the entire package of sheets, the screws being secured to the flanges by means of nuts.
• the front and rear flanges are generally formed from a non-magnetic material which conducts heat, for example a metal.
• the object of the present invention is to propose a solution which answers all or part of the aforementioned problems:
• a rotor for an electric motor comprising: a rotor shaft mounted to rotate about an axis; a plate pack mounted coaxially on the rotor shaft, said plate pack comprising a plurality of internal cavities; a plurality of permanent magnets housed within the internal cavities of the sheet bundle; at least one flange mounted axially on the rotor shaft.
• the at least one flange comprises at least one rod extending axially inside an orifice formed axially in the pack of sheets, and said at least one rod being equipped with at least one rod sensor.
• the rotor of the invention makes it possible to carry out measurements of physical parameters within the rotor itself. These measurements are therefore more reliable and make it possible, in the case of a measurement of the temperature of the rotor, to detect sufficiently early an overheating of said rotor and, therefore, to limit the risk of possible damage to the electric motor resulting from 'such overheating.
• the rotor can also have one or more of the following characteristics, taken alone or in combination.
• the rotor comprises a front flange and a rear flange mounted coaxially on the rotor shaft and arranged axially on either side of the pack of sheets.
• one of the front and rear flanges is formed from a plastic material and the other of said front and rear flanges is formed from metal, the density of the plastic flange being substantially equal to the density of the flange in metal.
• the metal flange is formed from aluminum.
• the orifice is a through orifice configured to allow a bolt to join said front and rear flanges.
• the at least one flange comprises at least one flange sensor, said flange sensor being a position sensor, or a vibration sensor, or any other type of sensor making it possible to perform a measurement of a datum. physical.
• at least one flange sensor is fixed to at least one flange by a fixing method chosen from overmolding, gluing, screwing, and clipping.
• the at least one flange sensor is printed directly on at least one flange.
• the at least one rod sensor is positioned on the rod so as to be at a distance from a permanent magnet of the plurality of permanent magnets counted radially, between 0 cm and 4 cm, and more particularly between 0 cm and 2 cm.
• the at least one rod sensor is in contact with at least one permanent magnet.
• the rotor comprises at least two rods each equipped with at least one rod sensor.
• the rotor comprises at least two rods, only one of which is equipped with at least one rod sensor.
• the at least one flange comprises two rods arranged in opposition with respect to the axis of the rotor shaft.
• said at least two rods are arranged radially at a substantially equal distance from the axis of the rotor shaft.
• the rotor can comprise three rods arranged so as to form an equilateral triangle on a section plane extending radially with respect to the axis of the rotor shaft.
• the rotor may comprise six rods arranged so as to form a hexagon on a section plane extending radially with respect to the axis of the rotor shaft.
• said rod sensors are arranged symmetrically with respect to the axis of the rotor shaft.
• the rotor includes a plurality of rod sensors, each rod sensor of the plurality of rod sensors having a different position along the axial direction of the rotor shaft.
• the at least one rod sensor is a thermal measurement sensor, and in particular a thermistor.
• the at least one rod sensor is in electrical connection with an electronic card, said electronic card being integral with the at least one flange.
• the electronic card is configured to communicate with an external control unit, for example by means of a contactless communication mode, such as Wifi, Bluetooth, or infrared.
• the electronic card is molded onto the flange of which it is integral.
• the electronic card is printed directly on the flange of which it is integral.
• the at least one flange is formed from a plastic material.
• the at least one rod sensor is fixed to the rod by a fixing method chosen from overmolding, gluing, screwing and clipping.
• the at least one rod sensor is printed directly on the rod.
• the invention relates to an electric motor comprising a rotor as defined above.
• FIG. 1 is an axial sectional view of the rotor according to a particular embodiment of the invention.
• FIG. 2 is a perspective view of a flange according to a first particular embodiment of the invention.
• FIG. 3 is a perspective view of a flange according to a second particular embodiment of the invention.
• FIG. 4 is a perspective view of a flange according to a third particular embodiment of the invention.
• FIG. 5 is a cross-sectional view of the rotor.
• FIG. 6 is an axial sectional view of an electric motor incorporating the rotor shown in FIG. 1.
• the invention relates to a rotor 10 for an electric motor 30 comprising a rotor shaft 12 mounted to rotate about an axis.
• the rotor 10 comprises a body formed by a pack of sheets 14, for example, formed in a ferromagnetic material, in particular steel, the pack of sheets 14 being mounted coaxially on the rotor shaft 12.
• the pack of sheets 14 is formed. of an axial stack of sheets which extend in a radial plane perpendicular to the axis of the rotor shaft 12.
• the rotor shaft 12 can for example be force-fitted inside a central opening of the sheet metal bundle 14 so as to rotate the rotor body 10 with the rotor shaft 12.
• the sheet pack 14 includes a plurality of internal cavities 15 within which a plurality of permanent magnets 16 are housed.
• a first end of the screws 24 may bear against the outer face of a front flange 17 mounted axially on one end of the rotor shaft 12, while the other end of the screws 24 may bear against the outer face. of a rear flange 19, mounted axially on the other end of the rotor shaft 12.
• the sheet metal pack 14 is clamped axially between the front flange 17 and the rear flange 19.
• These flanges 17, 19 make it possible to 'Balancing the rotor 10 while allowing good maintenance of the permanent magnets 16 inside their internal cavity 15.
• the balancing can be performed by adding or removing material from these flanges 17,19.
• the removal of material can be carried out by machining, while the addition of material can be carried out by implanting elements in openings provided for this purpose and distributed along the circumference of the flange 17, 19.
• Figures 1 to 4 illustrate different embodiments for which the orifices 20 are also configured to allow the passage of at least one rod 18, included on one of the front 17 or rear 19 flanges, and configured to extend axially. inside the orifice 20, said orifice being able to be extended by an opening in one of the front 17 or rear 19 flanges, each rod 18 being able to be equipped with at least one rod sensor 22.
• one of the front 17 and rear 19 flanges is formed from a plastic material and the other of said front 17 and rear 19 flanges is formed from metal, for example aluminum.
• the density of the plastic flange will be substantially equal to the density of the metal flange.
• the rod sensor 22 is in electrical connection with an electronic card, said electronic card being integral with at least one flange 17, 19.
• the electronic card can be configured to communicate with a control unit. external control, for example by means of a contactless communication mode, such as Wifi, Bluetooth, or infrared.
• This flange 17 or 19 has the shape of a disc extending in a radial plane perpendicular to the axis of the rotor shaft 12.
• the flange 17, 19 has a central orifice 21 for the coaxial mounting on the shaft 12 and several fixing holes 20 intended to receive the screws 24 axially passing through the whole of the sheet metal pack 14.
• At least one of the flanges 17,19 comprises at least one rod 18 on which is positioned at least one rod sensor 22 so as to be at a distance from a permanent magnet 16 of the plurality of permanent magnets 16 counted radially , between 0 cm and 4 cm, and more particularly between 0 cm and 2 cm. It is therefore possible that at least one rod sensor 22 is in contact with at least one permanent magnet 16.
• one or both front 17 or rear 19 flanges comprises at least one flange sensor 26.
• the flange sensor 26 can in particular be a position sensor, or vibration, or any other. type of sensor used to measure physical data.
• the flange 17 or 19 it is advantageous to form the flange 17 or 19 by molding a plastic material.
• the electronic card and / or the flange sensors 26 can thus be overmolded with the material constituting the flange 17 or 19.
• the electronic card or the flange sensors 26 can also be fixed on the flange 17 or 19 by gluing, screwing, or clipping or be printed directly on the flange 17 or 19.
• rod sensors 22 can also be fixed on the rod.
• FIG. 2 shows a configuration where the rotor 10 comprises two rods 18, arranged in opposition to the axis of the rotor shaft 12, and each equipped with a rod sensor 22.
• the two rods 18 are arranged radially at a substantially equal distance from the axis of the rotor shaft 12.
• Each rod sensor 22 can in particular be a thermal measurement sensor such as a thermistor.
• FIG. 3 shows another variant in which the rotor 10 comprises three rods 18 arranged so as to form an equilateral triangle on a section plane extending radially with respect to the axis of the rotor shaft 12.
• FIG. 4 shows another variant, in which the rotor 10 comprises six rods 18 arranged so as to form a hexagon on a section plane extending radially with respect to the axis of the rotor shaft. 12.
• the rod sensors 22 are arranged in the same orthogonal plane and symmetrically with respect to the axis of the rotor shaft 12, so as to avoid an imbalance of the flange 17, 19.
• the rotor 10 comprises a plurality of rods 18 comprising a plurality of rod sensors 22, each rod sensor 22 of the plurality of rod sensors 22 having a different position along the direction.
• the internal cavities 15 extend in a radial direction with respect to the axis of the rotor shaft 12 and are axially traversing. They have a substantially triangular section and are distributed uniformly around the axis of the rotor shaft 12. Two directly adjacent internal cavities 15 are separated by a radial segment 23 of the sheet pack 14 so that the rotor body is formed. alternating internal cavities 15 and segments 23 when following a circumference of rotor 10.
• Each internal cavity 15 houses a single permanent magnet 16 made of ferrite.
• the magnets permanent magnets 16 are orthoradially magnetized, i.e.
• each permanent magnet 16 which are adjacent to each other in the orthoradial direction are magnetized so as to be able to generate a magnetic flux in an orthoradial orientation with respect to the axis of the rotor shaft 12.
• end faces 25, 27 it is necessary to distinguish the face 27 corresponding to the North pole of the permanent magnet 16, represented by the letter N in FIG. 5, and the face 25 corresponding to the South pole of the permanent magnet 16, represented by the letter s in FIG. 5.
• the permanent magnets 16 located in two consecutive internal cavities 15 are of alternating polarities . Arranged in this way, the permanent magnets 16 generate, in the pack of sheets 14, a magnetic flux oriented radially and directed towards the outer periphery of the body of the rotor.
• the invention also relates to an electric motor 30 comprising a rotor 10 of the type of one of those described above.
• This electric motor 30 comprises in particular a casing in two parts housing the rotor 10 integral in rotation with the rotor shaft 12 and an annular stator 36 which surrounds the rotor.
• the housing consists in particular of a front bearing 32 and a rear bearing 34 connected to each other by means of bolts.
• the bearings 32, 34 are hollow in shape and each centrally carry a ball bearing 33 and 35 respectively for the rotational mounting of the rotor shaft 12.
• the chignons 37 project axially on both sides. other of the stator body 36 and are housed in the intermediate space separating the stator 36 from the respective bearings 32, 34.

Applications Claiming Priority (2)

Publications (1)

Family

ID=70457057

Family Applications (1)

Country Status (5)

Family Cites Families (4)

• 2020
  • 2020-03-26 FR FR2002967A patent/FR3108806B1/fr active Active
• 2021
  • 2021-02-05 WO PCT/FR2021/050220 patent/WO2021191515A1/fr unknown
  • 2021-02-05 EP EP21708059.7A patent/EP4128491A1/de active Pending
  • 2021-02-05 CN CN202180024598.6A patent/CN115485956A/zh active Pending
  • 2021-02-05 US US17/906,531 patent/US20230113826A1/en active Pending

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