Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K41/00—Propulsion systems in which a rigid body is moved along a path due to dynamo-electric interaction between the body and a magnetic field travelling along the path
  • H02K41/02—Linear motors; Sectional motors
  • H02K41/03—Synchronous motors; Motors moving step by step; Reluctance motors
  • H02K41/031—Synchronous motors; Motors moving step by step; Reluctance motors of the permanent magnet type
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
  • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
  • H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F7/00—Magnets
  • H01F7/02—Permanent magnets [PM]
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F7/00—Magnets
  • H01F7/02—Permanent magnets [PM]
  • H01F7/0205—Magnetic circuits with PM in general
  • H01F7/021—Construction of PM
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F7/00—Magnets
  • H01F7/02—Permanent magnets [PM]
  • H01F7/0205—Magnetic circuits with PM in general
  • H01F7/0221—Mounting means for PM, supporting, coating, encapsulating PM
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F7/00—Magnets
  • H01F7/02—Permanent magnets [PM]
  • H01F7/0231—Magnetic circuits with PM for power or force generation
• • 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
• • 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
  • H02K1/2793—Rotors axially facing stators
  • H02K1/2795—Rotors axially facing stators the rotor consisting of two or more circumferentially positioned magnets
• • 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
  • H02K21/24—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets axially facing the armatures, e.g. hub-type cycle dynamos

Definitions

• the present invention relates to a unitary magnet with a partially ovoid configuration and a magnet structure with several single magnets.
• the invention also relates to an electromagnetic actuator comprising one or more such magnet structures.
• the present invention finds an advantageous but non-limiting application for an electromagnetic actuator delivering a high power with a high rotational speed of the rotor, which is obtained by the use of one or more magnet structures according to the present invention.
• an electromagnetic actuator can be used for example in a fully electric or hybrid motor vehicle.
• the actuator may be a rotary actuator that may comprise at least one rotor flanked by two stators, these elements being superposable relative to one another by being separated by at least one air gap on the same shaft.
• the rotor comprises a body in the form of a disk having two circular faces connected by a thickness, the disk being delimited between an outer ring and an inner periphery defining a recess for a rotation shaft.
• At least two permanent magnets are applied against at least one of the two circular faces of the so-called support surface body.
• a single-gap rotor intended to be associated with a stator only one circular face of the body carries magnets while, for a rotor with two air gaps with a respective stator, it is the two faces which carry magnets.
• the magnets are each held on the face or their respective face by holding means, an interval being left between said at least two magnets on the same face.
• the rotor For an electromagnetic radial flow actuator, the rotor comprises a cylindrical body whose entire periphery carries magnets.
• stator or each stator they carry winding elements comprising a tooth carrying a coil, the tooth being framed on each of its sides by a notch, a good conductor wire being wound on the tooth to form the coil.
• the rotor which is secured to the output shaft of the motor is subjected to a torque resulting from the magnetic field, the magnetic flux created being an axial flow for an axial flow electromagnetic machine and a radial flow for a radial flow machine.
• magnets can be demagnetized when subjected to high temperatures.
• U S-A-2011/080065 discloses an axial flow motor rotor with a plurality of magnet structures disposed around the rotor and composed of a plurality of unit magnets.
• the rotor described in this document has been developed on the observation that the permanent magnets in such an engine are exposed to a high temperature due to the heat generated by the windings and have a significant probability of demagnetization by the demagnetizing field of the windings. There is therefore a demand for magnets in which the coercive force which is an index of thermal resistance and resistance to demagnetization is greater than a certain level.
• Effective means for reducing eddy currents is to divide a magnetic body to interrupt the eddy current path. While the division of a magnet body into smaller pieces leads to a greater reduction in eddy current losses, it becomes necessary to take into account problems such as an increase in the cost of manufacture and a decrease in performance.
• each of the divided unit magnets has a coercive force near the surface of the magnet piece higher than that inside the unit magnet. This is a difficult measure to implement and expensive.
• unit magnets are glued face to face in the form of cubes which contributes to their demagnetization and does not allow a heat exchange with the outside of the magnets.
• GB-A-733 513 discloses a unitary magnet having a first, more or less straight cylindrical portion forming a body of the unitary magnet having a larger section and extending over a greater length of the unit magnet than at least one second longitudinal end portion pointing towards an associated longitudinal end of the magnet while decreasing in section towards the longitudinal end.
• This document relates to a unit magnet housed in a ballpoint pen and not to a unitary magnet grouped with other unitary magnets to form a magnet structure grouping all the unit magnets.
• US-A-4,555,685 relates to magnets of large size. These large magnets are trapezoidal in shape but they are not joined together to form a compact magnet structure.
• the present invention relates to a three-dimensional magnet structure consisting of a plurality of unit magnets, characterized in that the unit magnets are elongated in an ellipsoid of revolution or polygonal, each unit magnet comprising a first portion forming a body of the unitary magnet having a larger section and extending over a greater length of the unit magnet than at least a second longitudinal end portion pointing to an associated longitudinal end of the magnet decreasing by section approaching the longitudinal end, the unit magnets being directly adjacent to each other being partially in contact, the magnets being glued by adhesive deposition on the areas of the unit magnets in contact, the plurality of unit magnets achieving a mesh of magnets without interposition of elements of maintenance between them others es that glue.
• the ideal form of this stud is an ellipsoid of symmetrical revolution also called ovoid shape, approximately a flattened sphere, which by its topology is difficult to demagnetize because its field magnetic relative to the magnetization is formless. There is no rotating field in the corners.
• the inventive step of the present invention is to form a mesh of unit magnets closest to the ellipsoid of revolution.
• the ovoid shape of the unitary magnet may be more or less perfect by having a convex rounded end portion at a longitudinal end or at both longitudinal ends.
• a relatively perfect ovoid shape with two longitudinal ends of convex shape is optimal but difficult to obtain by machining. By cons it is the ideal form to fight a demagnetization of the unitary magnet.
• a unitary magnet based on a poly-faceted structure with a first portion of said body with longitudinal facets and at least one end portion with inclined facets whose angles are between 0 and 45 ° can also be considered by making it possible to increase the magnetic field relative to the magnetization while maintaining significant active faces at the ends of the unit magnets in the form of pads.
• crystals associated with each other which are not bonded over the entire surface of facets or longitudinal faces, but layers of resin and glue are substituted on the large base of the facets at 45 ° and on the longitudinal facets advantageously provided with chamfers in order to construct a mesh network at the ends of the poly-faceted studs with contact zones between limited magnets.
• the contact between two adjacent unitary magnets is smaller and can only be punctual and corresponds substantially to a reduced-size circular arc between the two unitary magnets. It can be hollowed out to the size of the arc of contact between two adjacent unit magnets to receive glue, preferably in the form of resin.
• Unit magnets are not bonded on the side faces, at most on facets or edges of facets.
• Layers of resin and glue are substituted, for example, on the large base of the 45 ° facets and on the longitudinal facets advantageously provided with chamfers to construct a mesh network at the ends of the poly-faceted pads.
• said at least one second longitudinal end portion is curved while being convex, a vertex of the shape convex shape forming the associated longitudinal end. This gives a perfect end shape of an ovoid.
• said at least one second longitudinal end portion carries at its apex a median facet forming the longitudinal end. This forms a truncated or flattened bevel or apex at the end of the longitudinal end.
• said at least one second longitudinal end portion comprises lateral facets inclined towards a longitudinal axis of the magnet while approaching the associated longitudinal end of the magnet, the inclined lateral facets extending between a large base connected to the first body portion of the magnet and a small base forming a longitudinal end of the magnet.
• the second end portion is constituted by inclined facets.
• the inclined lateral facets are curved while being convex. This makes it possible to get closer to the perfect ovoid shape for one or both longitudinal ends.
• the longitudinal end of the magnet comprises a medial facet surrounded by the inclined lateral facets.
• the longitudinal end or the longitudinal ends of the unit magnet are then bevelled.
• each longitudinal end portion of the magnet comprises a second longitudinal end portion.
• the first body portion of the unitary magnet having a larger section and extending over a greater length of the unitary magnet is curved with its largest section towards a longitudinal middle portion of the magnet and decreasing in section towards the longitudinal ends of the magnet.
• This is an alternative to a first polygonal portion including facets or a first portion of cylindrical shape.
• the first body portion of the unitary magnet is of polygonal shape with longitudinal or cylindrical facets of circular or oval section. The first body portion of the unitary magnet is not rounded in this case and does not tend to a perfect ovoid shape.
• each of the inclined side facets of said at least one second portion is extended longitudinally in the unit magnet by a longitudinal facet of the first portion.
• the areas of the unit magnets in contact have chamfers cut in an outer contour of each unit magnet in contact with another unitary magnet, the glue deposit concerning exclusively the chamfers of the unit magnets.
• the invention also relates to a linear or rotary electromagnetic actuator, characterized in that it comprises such a magnet structure or a plurality of such magnet structures, the magnet structure (s) forming part of a rotating rotor around its center, where the magnet structures are arranged concentrically at the center of the rotor.
• the magnet structure forms a single magnet extending over the actuator or, when multiple, the magnet structures are successive blocks forming successive alternating magnet poles.
• the invention finally relates to a method of manufacturing such a magnet structure, characterized in that it comprises the following steps:
• the basic approach of the present invention is therefore that the hold between the unit magnets is ensured without the need for a mesh housing the individual magnets individually, which represents a saving of space and makes it possible to house more single magnets per magnet structure.
• an injection of a layer of composite around the unit magnets and brought into contact and glued for their coating is advantageousously possible to obtain a compact magnet structure by filling the interstices between unit magnets.
• FIGS. 1a, 1b and 1c are schematic representations respectively of a front view of a magnet structure containing a plurality of unit magnets, an enlarged view of this magnet structure and a view of perspective of a unitary magnet in the form of an elongated stud according to a first embodiment of the present invention, the unitary magnet comprising at least a longitudinal end portion of ovoid shape with inclined facets,
• FIGS. 2a, 2b and 2c are schematic representations respectively of a front view of a magnet structure containing a plurality of unit magnets, an enlarged view of this magnet structure and a perspective view of a unitary magnet in the form of an elongate pad according to a second embodiment of the present invention, the unitary magnet comprising at least one longitudinal end portion of ovoid shape with inclined facets, the inclined facets being curved,
• FIGS. 3a, 3b and 3c are diagrammatic representations respectively of a front view of a magnet structure containing a plurality of unit magnets, an enlarged view of this magnet structure and a perspective view of a unitary magnet in the form of an elongate pad according to a third embodiment of the present invention, the unitary magnet having a substantially perfect ovoid shape with two curved longitudinal end portions,
• FIG. 4 is a schematic representation of a perspective view of a magnet structure according to the present invention housing unit magnets according to the second embodiment, unit magnets being shown at a distance from the magnet structure for to be more visible,
• FIG. 5 is a diagrammatic representation of a perspective view of a rotor comprising a plurality of magnet structures, the rotor forming part of an electromagnetic actuator according to the present invention, the portion framed A in this figure referring to FIG. figure 4.
• transverse to the unitary magnet means being in a plane perpendicular to a longitudinal axis of the elongate unitary magnet having a stud shape.
• the present invention relates to a unitary magnet 1 of elongated shape that can be considered as a pad.
• Elongated shape means that its length is notoriously larger than its width.
• the unitary magnet 1 has an at least partially ovoid contour.
• the unitary magnet 1 comprises a first portion 1a forming the body of the unitary magnet 1 having a larger section and extending over a greater length of the unitary magnet 1 than at least a second end portion 1b. longitudinal pointing to an associated longitudinal end of the magnet decreasing section approximating the longitudinal end.
• the unitary magnet 1 comprises a single second end portion 1b.
• the first 1a and second portions 1b of the unitary magnet 1 each comprise facets, longitudinal facets 3 for the first portion 1a and inclined lateral facets 4 towards the longitudinal end associated with the second portion 1b.
• the unitary magnet 1 comprises two second end portions 1b respectively for a longitudinal end of the unitary magnet 1.
• the first 1a and second portions 1b of the unitary magnet 1 each comprise facets. , longitudinal facets 3 for the first portion 1a and facets inclined 4 towards the longitudinal end associated with the respective second portion 1b.
• the inclined facets are curved.
• the unitary magnet 1 has an almost perfect ovoid shape with a first portion 1a and two second end portions 1b rounded and convex shape.
• At least one second longitudinal end portion 1b may be convexly curved, with or without inclined facets 4.
• a vertex of the convex shape may form the associated longitudinal end . It can be considered that the second end portion 1b of FIG. 1c is of convex shape with reference to the edges of the inclined facets 4.
• At least a second longitudinal end portion 1b carries at its apex a median facet 5 forming the longitudinal end. This is the case in Figures 1c, 2c and 3c although this is not mandatory.
• At least a second longitudinal end portion 1b may comprise lateral facets inclined towards a longitudinal axis of the magnet, approaching the associated longitudinal end of the magnet.
• the inclined lateral facets 4 can extend between a large base 4a connected to the first portion 1a forming the body of the magnet and a small base forming a longitudinal end of the magnet, the median facet 5 then forming the small base.
• the inclined side facets 4 can be convex curved.
• Figures 2c and 3c show two second longitudinal end portions 1b at a respective longitudinal end of the unitary magnet 1.
• the first portion 1 having the body of the unitary magnet 1 having a larger section and extending over a greater length of the unitary magnet 1 can be curved with its largest section towards a longitudinal median portion of the magnet and decreasing section towards the longitudinal ends of the magnet, this to better tend to an ovoid shape. This is the case in FIG. 3c but the case illustrated in FIG. 3c is not limiting of this embodiment.
• the first portion 1 forming the body of the unitary magnet 1 may be of polygonal shape with longitudinal facets 3.
• the first portion 1a may be of cylindrical shape of circular or oval section.
• each of the inclined lateral facets 4 of the second portion or portions 1b are longitudinally extended in the unit magnet 1 by a longitudinal facet 3 of the first portion 1a, one end of an inclined facet 4 of the second or portions 1b being placed end to end with an end of an associated longitudinal facet 3 of the first portion 1a.
• the invention relates to a three-dimensional magnet structure 2 consisting of a plurality of unitary magnets 1. Patterns made by the unit magnets 1 are different according to the design of these unit magnets 1.
• each unit magnet 1 is as previously mentioned, the unit magnets 1 being directly adjacent to each other being partially in contact.
• the unit magnets 1 are glued by adhesive deposition on the areas of the unit magnets 1 in contact. It follows that the plurality of unitary magnets 1 produces a mesh of unit magnets 1 without the interposition of holding elements between them other than the adhesive, for example cells respectively housing a unitary magnet 1.
• Unit magnets 1 are in direct but partial contact between adjacent magnets. This is particularly clearly visible in FIG. 4 and in enlarged figures 1b, 2b and 3b.
• the areas of the unit magnets 1 in contact may have chamfers 6, 6a cut into an outer contour of each unit magnet 1 in contact with another unit magnet 1, the adhesive deposit relating to exclusively the chamfers 6, 6a of the single magnets 1.
• the chamfers 6 can be located on each of the edges of the longitudinal facets 3 when present, be located on the almost point contact between two unitary magnets 1 perfectly ovoid or chamfers 6a can be located on the large base 4a of the second portion 1b when this second portion 1b have inclined facets 4 curved or not.
• the invention also relates to a linear or rotary electromagnetic actuator comprising such a magnet structure 2 or more of such magnet structures 2, the magnet structure (s) 2 being part of a rotor 7 rotating about its center as shown in Figure 5 for an axial flow actuator.
• the magnet structure or structures 2 are arranged concentrically in the center of the rotor 7, advantageously separated by branches 8 in the case of several magnet structures 2 and framed on the one hand by a hub 10 and a hoop 9.
• the branches 8 leave the hub 10 and end at the band 9 forming the outer periphery of the rotor 7.
• the actuator shown in Figure 5 is axial flow but could also be radial flow.
• the magnet structure 2 can form a single magnet extending over the actuator.
• the magnet structures 2 are successive blocks forming successive alternating magnet poles.
• the invention finally relates to a method of manufacturing such a magnet structure 2.
• the method comprises a step of cutting in a magnetized tile having a length, a width and a thickness forming three dimensions of the tile, of several single magnets 1 according to the three dimensions of the magnetized tile, the unit magnets 1 having at least partially an ovoid shape.
• the method then comprises a step of determining partial contact areas on each unit magnet 1 with each magnet adjacent thereto when magnets are adjacent to each other.
• the partial contact zones depend on the outer contour of the unit magnets 1.
• the next step is the bonding of each unit magnet 1 by depositing a resin for each unit magnet 1 only on the determined partial contact zones.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Permanent Field Magnets Of Synchronous Machinery (AREA)
• Manufacturing Cores, Coils, And Magnets (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=62067646

Family Applications (1)

Country Status (7)

Families Citing this family (2)

Family Cites Families (16)

• 2018
  • 2018-01-26 FR FR1800086A patent/FR3077414B1/fr active Active
• 2019
  • 2019-01-18 CN CN201980009788.3A patent/CN111868855B/zh active Active
  • 2019-01-18 US US16/769,181 patent/US11323016B2/en active Active
  • 2019-01-18 EP EP19705220.2A patent/EP3743929A1/fr not_active Withdrawn
  • 2019-01-18 WO PCT/IB2019/050420 patent/WO2019145831A1/fr unknown
  • 2019-01-18 JP JP2020535091A patent/JP2021511765A/ja active Pending
  • 2019-01-18 RU RU2020125693A patent/RU2020125693A/ru unknown

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