• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a rotor (1) of an electromagnetic motor or generator having a body comprising an internal hub (2) concentric with a central axis (7) of rotation of the rotor (1), branches (3) extending radially with respect to the central axis (7) of rotation from the internal hub (2) towards a hoop (8) forming a circular external periphery of the rotor (1), at least one magnet or a structure of magnet (10) being housed in each space delimited between two adjacent branches (3). Each branch (3) has a decreasing width away from the internal hub (2) to end with a tapered point (3b) against the hoop (8) and each magnet or magnet structure (10) has an increasing width ( la) moving away from the internal hub (2) to finish against the hoop (8) surrounding the rotor (1).
    公开号:FR3083023A1
    申请号:FR1800691
    申请日:2018-06-22
    公开日:2019-12-27
    发明作者:Loic Mayeur；Romain Ravaud
    申请人:Whylot SAS；
    IPC主号:
    专利说明:

    "Rotor for electromagnetic motor or generator with tapered arms"
    The present invention relates to a rotor for an electromagnetic axial flow motor or generator having an advantageously enlarged hub from which tapering branches leave with at least one magnet structure between two adjacent branches. The invention also relates to an electromagnetic motor or generator equipped with such a rotor.
    The present invention finds an advantageous but non-limiting application for an electromagnetic motor delivering a high power with a high rotational speed of the rotor, which is obtained by the specific characteristics of the rotor according to the present invention. Such a motor can be used, for example, as an electromagnetic motor in a fully electric or hybrid motor vehicle.
    Advantageously but not limited to, the electromagnetic motor or generator can comprise at least one rotor framed by two stators, these elements being able to be superposed relative to each other by being separated by at least one air gap on the same shaft.
    In high speed applications, it is necessary to have very good mechanical strength of the rotating part, that is to say the rotor, in order to improve the reliability of the system.
    For an electromagnetic axial flow machine, the rotor comprises a body in the form of a discoidal support for magnets having two circular faces connected by a thickness, the disc being delimited between an external crown formed by a hoop and an internal periphery delimiting a recess for a rotation shaft.
    The magnets are each held in the disc support by holding means, an interval being left between the magnets.
    Axial flux motors are often used as an engine having higher torque than radial flux motors. They can therefore be used in low speed applications.
    For high-speed applications, the design of the rotor in an axial flow motor is more delicate since the forces due to centrifugal effects cause fairly significant mechanical stresses in the rotor. Furthermore, eddy current losses become preponderant both in the magnets and also in the rotor part when this is made with electrically conductive materials.
    For a rotor which must rotate at high rotational speeds, the main disadvantage of a motor at high rotational speed lies in the high probability of detachment of the magnet or magnets from the rotor as well as at least partial breakage of the rotor. . The rotor of such an engine must therefore be able to withstand high rotational speeds.
    The state of the art pushes the skilled person to stiffen the disc support of the magnet or magnets to combat centrifugal force. This requires a specific material for the disc support and to increase its size by thickening it so that the disc support is more rigid.
    This was not entirely satisfactory because the engine or generator thus endowed with a discoidal support has a heavier weight as well as an increased manufacturing price.
    One solution may be to make meshes of elongated unit magnets in fibrous and resinous structures, so as to reduce the eddy currents and to use a body of composite material for the rotor which does not conduct electricity, ideally a fiberglass rotor, with a hoop placed at the periphery of the rotor so as to maintain the forces due to centrifugal effects.
    However, for applications where the linear speeds become very high, the mechanical stresses become such that it is necessary to reduce the mass of magnet in order to access these speeds of rotation. However, the torque that an electric machine must provide is proportional to the area of magnets interacting with the magnetic fields produced by the stators. A reduction in the surface of the magnets therefore results in a reduction in the torque and therefore in the power of the machine.
    The problem underlying the present invention is to design a rotor for the support of several permanent magnets provided with a hoop for an electromagnetic machine with axial flux which can, on the one hand, hold the permanent magnets that the rotor supports from effectively by preventing the magnets from detaching from the rotor while effectively compensating for the centrifugal force and, on the other hand, having a mechanical resistance such that the rotor can rotate at very high speeds.
    To this end, the present invention relates to a rotor of an electromagnetic motor or generator having a body comprising an internal hub concentric with a central axis of rotation of the rotor, branches extending radially with respect to the central axis of rotation from the internal hub to a hoop forming a circular external periphery of the rotor, at least one magnet or a magnet structure being housed in each space delimited between two adjacent branches, characterized in that:
    • each branch has a decreasing width away from the internal hub to finish with a tapered tip against the hoop, • each magnet or magnet structure has an increasing width as it moves away from the internal hub to finish against the hoop surrounding the rotor.
    The configuration of the rotor according to the present invention is based on the observation that the maximum stresses applying at very high speed on a rotor are made at the level of the hub surrounding the median axis of rotation of the rotor. It is therefore appropriate to solidify this internal portion of the rotor. This is to the detriment of the magnets placed in this area which must be replaced by an enlarged hub. It is also advisable to equip the rotor with relatively thick branches at least at their connection with the hub. The more we thicken the shape of the branches, the less magnets we put.
    The main idea underlying the present invention is that the arms need not be thickened essentially only at their connection with the hub, the stresses exerted on the rotor decreasing the further one moves away from the center of the rotor.
    For applications where the linear speeds become very important, typically from 160 meters per second or 180 meters per second, the mechanical stresses become such that the mass of magnet has to be reduced in order to access these speeds of rotation. . This has the great disadvantage that the torque that an electric machine must provide is proportional to the area of magnets interacting with the magnetic fields produced by the stators. A reduction in the surface of the magnets therefore results in a reduction in the torque and therefore in the power of the machine. There is thus a strong prejudice in increasing the width of the branches at the level of the external periphery of the hub, especially when the radius of the hub is also increased.
    The Applicant has become aware that, in the case of an axial flow machine, the torque is proportional to the cube of the radius of the rotor. Therefore, it is smarter to add magnet area to the periphery of the rotor than in more internal portions of the rotor. Hence an absence of a magnet near the axis of rotation can be easily compensated for by the addition of a magnet at the periphery of the rotor, which can be obtained by configurations of branches decreasing in width the further one moves away from the center of the rotor until they are only tapered points with a width close to zero.
    It is therefore desirable to increase the surface area of the section of the rotor arms at their connection with the hub and to decrease this section gradually in order to increase the section of the magnet surfaces to maintain a high motor torque.
    This had never been envisaged by the state of the art which used only branches of constant width and hubs of small radius to make room for magnets. There was therefore a strong prejudice in reducing the distribution of the magnets on the rotor to increase the mechanical resistance of the rotor and the state of the art was oriented towards other solutions such as an increase in the axial direction of the branches and of the hub, this which increased the weight of the rotor without having a great beneficial effect on its resistance.
    Advantageously, the tapered tip of each branch is at least half the width of a base of the branch connected to the internal hub.
    Advantageously, the bases of two adjacent branches are separated by an intermediate portion of the internal hub, the intermediate portion being of concave shape rounded in the direction of the axis of the rotor, the internal hub having a radius equal to at least a quarter of a rotor radius.
    The inward curvatures of the intermediate portions between arms make it possible to reduce the mechanical stresses at the level of the thickest section of the arms bearing on the external periphery of the hub.
    Advantageously, the hub and the branches are made of glass fibers cast in resin. These reinforcing fibers help to increase the resistance of the magnet structure and in particular the bending and buckling rigidity.
    Advantageously, the hub and the branches are in one piece. This increases the mechanical resistance of the assembly and consequently of the rotor.
    Advantageously, each magnet structure consists of a plurality of unit magnets secured by an insulating material reinforced with fibers, each unit magnet being of elongated shape extending in the axial direction of the rotor.
    Another synergy provided by the present invention is that the rotor can have, between each branch, unitary magnets grouped together in a magnet structure. Each three-dimensional magnet structure consists of a plurality of unit magnets.
    This allows for a magnet structure having many unitary magnets. It has been revealed that a structure with such a plurality of unit magnets has a great power of not being sensitive to space harmonics or currents generated by the stator windings. Consequently, the losses generated in the magnet structures are very low, and the yields, particularly at high speed, are very high. Such a magnet structure can form a magnet pole or be a complete magnet.
    One of the preferred measures of the present invention is to decompose a magnet structure which may be a whole magnet or a magnetic pole according to the state of the art into a plurality of small or micro magnets. A large magnet is subject to greater eddy current losses than its equivalent in small or micro-magnets. The use of small magnets or micro-magnets therefore makes it possible to reduce these losses which are detrimental to the operation of the electromagnetic actuator.
    It is known that, in order to obtain a magnetic field of optimal intensity, the ideal volume of a magnet must approach a cube or a cylinder whose length is equal to the diameter. It is common knowledge that increasing the length of a magnet beyond it does not increase the magnetic field. The approach of the present invention in this preferred form, however, goes in the opposite direction of this prejudice.
    The length of a unitary magnet is appreciably increased with respect to the diameter or to a diagonal of its planar longitudinal face compared to what is widely practiced, this essentially to meet the needs for mechanical strength of the structure, which is the main object of the present invention.
    The Applicant has discovered that a plurality of unit magnets in a magnet structure gives a magnet structure having a much greater mechanical resistance while retaining magnetic properties almost similar to those of a single magnet having a surface equal to n times the elementary area of the n unit magnets when n unit magnets are present.
    Advantageously, each unitary magnet of the plurality of unitary magnets is of polygonal shape or each unitary magnet has an at least partially ovoid outline by comprising a first portion forming the body of the unitary magnet having a larger section and extending over a greater length of the unitary magnet than at least a second longitudinal end portion pointing towards an associated longitudinal end of the magnet, decreasing in section as it approaches the longitudinal end.
    Ovoid magnets can have facets. One thus obtains as unitary magnets crystals associated with one another which are not linked over the entire surface of facets or longitudinal faces but layers of resin and glue come to build a mesh network at the ends of the poly-faceted studs with zones of contact between magnets limited.
    As an alternative, for unit magnets of perfect ovoid shape with a first rounded portion, the contact between two adjacent unit magnets 30 is more reduced by being able to be only punctual and corresponds substantially to an arc of circle of reduced size between the two. unit magnets. A groove can be dug to the dimension of the arc of a contact circle between two adjacent unitary magnets to receive glue, advantageously in the form of resin.
    Advantageously, each magnet structure incorporates at least one mesh having meshes each delimiting a housing for a respective unitary magnet, each housing having sufficient internal dimensions sufficient to allow a unitary magnet to be introduced into its interior while leaving a space between the housing and the unitary magnet filled with a fiber-reinforced resin, the meshes being made of insulating material reinforced with fibers.
    The mesh remains in place and can also be coated in a layer of composite. Such a mesh makes it possible to maintain unitary magnets during the manufacture of the magnet structure and has the advantage of representing an additional solidification element of the magnet structure, the mesh possibly also containing reinforcing fibers.
    For example, a honeycomb mesh is known to reinforce the resistance of an element, in this case a magnet structure. The unit magnets are inserted in hexagonal housings which ensure their maintenance. The walls of the housings serve as electrical insulation and the density of the housings in the magnet structure can be considerably increased. The honeycomb mesh can be made of an insulating composite material reinforced with fibers.
    Advantageously, the hoop is made of glass fibers or carbon fibers. The composite hoop circumferentially surrounds large magnets or magnet structures at an outer periphery of the rotor. The hoop contributes, if necessary, to the radial retention of the magnets in addition to that guaranteed by the external coating layer of composite. The tapered tips of the branches can be joined or not the hoop.
    Advantageously, each magnet or magnet structure between two adjacent branches is embedded in a layer of composite, the rotor also being coated in a layer of composite.
    Advantageously, cover discs are arranged on each circular face of the rotor.
    This is mainly but not only true for magnet structures having a plurality of unit magnets. The large magnets used for the rotor according to the prior art dissipated a large amount of heat. This dissipation prevented the use of axial retention means in the form of composite cover discs and the heat dissipation could have consequences on the behavior of the coating with accelerated aging of this coating as well as magnets.
    Composite cover discs were not frequently used in the prior art because they did not resist the heat dissipation generated by the magnets.
    As the present invention preferably uses a multitude of unit magnets replacing a compact magnet of the prior art, the heat dissipation is less and cover discs can be used as axial holding means, these discs advantageously replacing means of axial retention between magnets and rotor body, necessitating if necessary modifications of the magnets or of their coating to produce additional fixing means with fixing means carried by the rotor.
    The invention also relates to a method of manufacturing such a rotor, in which the width of each branch at a point of its length extending radially from the external periphery of the hub to the internal periphery of the hoop is determined from '' an evaluation of an admissible mechanical stress likely to be applied to the rotor, of a maximum admissible speed of rotation of the rotor and of a mechanical resistance of the material of the branch, a decrease in the width of each branch away from the hub being obtained by selecting for each branch a width for each point of its length making it possible to obtain an iso-stress inside the branch.
    Without being limiting, the maximum stress exerted on a branch towards its end connected to the hub can be evaluated at 120 mega Pascals. Obtaining this iso-stress makes it possible to minimize the width of the branch and therefore to put more surface area of large magnets or magnet structures, therefore in the latter case more unit magnets, which allows to obtain more torque and more than compensate for the loss of magnet surface towards the hub.
    Advantageously, the width I of each branch at a point of its length extending radially is given by the following equation:
    lcrnK — eW‘r ‘στη
    K being a constant varying according to a thickness of the hoop and representative of the mechanical resistance of the material of the branch, p a density of the magnet or of the magnet structure, m an admissible mechanical stress capable of being applied to the rotor and consequently on the branch, d'ouverture an opening angle of each magnet or of each magnet structure and W the maximum permissible speed of rotation of the rotor.
    The invention finally relates to an electromagnetic motor or generator with axial flow, characterized in that it comprises at least one such rotor, the motor or electromagnetic generator comprising at least one stator carrying at least one winding, the motor or the electromagnetic generator. comprising one or more air gaps between said at least one rotor and said at least one stator.
    Advantageously, the electromagnetic motor or generator comprises at least one rotor associated with two stators.
    Other characteristics, aims and advantages of the present invention will appear on reading the detailed description which follows and with regard to the appended drawings given by way of nonlimiting examples and in which:
    - Figure 1 is a schematic representation of a front view of a rotor for an electromagnetic machine with axial flow according to a first embodiment of the present invention, magnet structures composed of unitary magnets being inserted each between two adjacent branches of a disc-shaped support for the magnets, the branches having a width which decreases away from the hub of the rotor,
    FIG. 2 is an enlarged schematic representation of a portion of the rotor shown in FIG. 1,
    - Figures 3a, 3b and 3c are schematic representations for Figures 3a and 3b of a respective embodiment of a unitary magnet of ovoid shape and for Figure 3c of a magnet structure comprising unitary ovoid magnets , four ovoid unit magnets being shown spaced from the magnet structure,
    - Figure 4 shows a branch width curve of a rotor according to the present invention as a function of a point located at a distance r from the central axis of rotation of the rotor, the branch having a width decreasing away from the central axis of rotation of the rotor.
    The figures are given by way of examples and are not limitative of the invention. They constitute schematic representations of principle intended to facilitate the understanding of the invention and are not necessarily at the scale of practical applications. In particular the dimensions of the different parts are not representative of reality.
    In what follows a single branch 3, a single base 3a and a single tapered tip 3b of the branch 3 are referenced for all the branches in FIGS. 1 and 2. It is the same for a single magnet structure referenced 10 with internal faces 10a and external 40b, an intermediate portion 9 between two branches for all the intermediate portions.
    In FIG. 2, a single unitary magnet 4 is referenced for all the unit magnets as well as a single layer of glue 6 between unit magnets and a single external layer 5 enveloping a magnet structure
    10.
    Everything stated for one of these referenced elements applies to all similar unreferenced elements.
    Referring to all the figures and more particularly to Figures 1 and 2, these figures respectively show a rotor 1 and an enlargement of a portion of a rotor 1 according to the present invention with two branches 3 interposing between them a structure of magnet 10 composed of several unitary magnets 4 polygonal.
    This is not limiting and a large single magnet can be inserted between two branches 3, this large single magnet not being to be confused with the unit magnets 4 of a magnet structure 10 visible and referenced to Figure 2.
    Such a rotor 1 is used in an electromagnetic motor or generator, advantageously with axial flow. The rotor 1, advantageously substantially circular, has a body comprising an internal hub 2 concentric with a central axis 7 of rotation of the rotor 1 or longitudinal median axis of the rotor 1. Branches 3 extend radially in the rotor 1 relative to the central axis 7 of rotation from the internal hub 2 towards a hoop 8 forming a circular external periphery of the rotor 1.
    At least one magnet, then a large magnet or a magnet structure 10 comprising a plurality of small unit magnets 4 is housed in each space delimited between two adjacent branches 3.
    According to the present invention, each branch 3 has a width I, visible in FIGS. 1 and 4, decreasing as it moves away from the internal hub 2, ending with a tapered tip 3b against the hoop 8. The width I is shown for the greatest width of a branch 3 in FIG. 1, that is to say at the base 3a of this branch 3a connected to the hub 2.
    Each large magnet or magnet structure 10 has an increasing width away from the internal hub 2 to end against the hoop 8 surrounding the rotor 1. This is the largest width of the magnet or structure magnet 10 which illustrates the width la in Figure 1.
    The space lost for the magnets by increasing the width I of the branches 3 towards their end portion or base 3a opposite the hub 2 and, if necessary, also by increasing the radius of the hub 2 is made up on the peripheral end portions of the rotor 1. The fact of placing each large magnet or each magnet structure 10 with their greatest width oriented towards the external periphery of the rotor 1 makes it possible to increase the parts of the magnet placed at the periphery of the rotor 1 and therefore increase the total magnetization area.
    Still referring to FIGS. 1 and 2, the tapered tip 3b of each branch 3 can be at least two to four times less wide than a base 3a of the branch 3 connected to the internal hub 2.
    As can best be seen in FIG. 2 for a single base 3a, the bases 3a of two adjacent branches 3 can be separated by an intermediate portion 9 of the internal hub 2. This intermediate portion 9 may be of concave shape rounded in the direction of the axis of the rotor 1. Likewise, as an alternative or in association, with particular reference to FIG. 1, the internal hub 2 may have a radius ri equal to at minus a quarter of a radius of the rotor 1, making it a hub 2 larger than a hub 2 of the prior art. The radius of the rotor is equal to the radius re of a branch 3 to which radius re is added a hoop thickness 8.
    The hub 2 and the branches 3 can be made of glass fibers cast in resin. Resistant plastic fibers can also be used in order to increase the resistance of the rotor 1 and in particular the bending and buckling rigidity.
    To solidify the rotor 1, the rotor 1 and the branches 3 may be in one piece. The branches 3 can be secured or not to the hoop 8 by their tapered end 3b.
    Referring to FIGS. 1, 2, 3a to 3c, each magnet structure 10 can consist of a plurality of unit magnets 4 secured by an insulating material reinforced with fibers, each unit magnet 4 being of elongated shape in s 'extending in the axial direction of the rotor 1. The unit magnets 4, only one of which is referenced by figure, are not to be confused with the magnet structures 10 nor with large magnets not shown in the figures.
    It follows that each magnet structure 10 can be three-dimensional and made up of a plurality of unit magnets 4.
    In FIGS. 1 and 2, each unit magnet 4 of the plurality of unit magnets 4 is of polygonal shape.
    In FIGS. 3a, 3b and 3c, each unitary magnet 4 can have an at least partially ovoid contour by comprising a first portion 4a forming the body of the unitary magnet 4 having a larger section and extending over a greater length of l unitary magnet 4 that at least a second portion 4b of longitudinal end pointing towards an associated longitudinal end of unitary magnet 4 by decreasing in section as it approaches the longitudinal end.
    In FIG. 3a, the unit magnet 4 has an almost perfect ovoid shape with a first portion 4a and two second portions 4b of rounded end and of convex shape. As can be seen in FIG. 3c, the contact between two adjacent unitary magnets 4 and ovoid is substantially punctual or extends in a limited arc.
    In this case, the unitary magnet 4 can have an at least partially ovoid outer contour with the first portion 4a forming the body of the unitary magnet 4 having a larger section and extending over a greater length of the unitary magnet. 4 that said at least one second portion 4b.
    In FIG. 3b, the unitary magnet 4 can have at least a second portion 4b at at least one longitudinal end of the unitary magnet 4 as an extension of the first portion 4a. There may be two second portions 4b with a second portion 4b respectively at a longitudinal end of the unitary magnet 4.
    The second portion (s) 4b can point towards an associated longitudinal end of the magnet by decreasing in section by approaching the longitudinal end.
    As shown in FIG. 3b, the second portion (s) 4b of longitudinal end can be curved while being convex in shape. The second portion (s) 4b of longitudinal end may terminate at their longitudinal end associated with a median facet 11 forming the longitudinal end. In FIG. 3b, for the ovoid shape, this median facet 11 forming the longitudinal end is however domed and is only optional.
    In this FIG. 3b, the second portion or portions 4b of longitudinal end may include lateral facets inclined towards a longitudinal axis of the unitary magnet 4 while approaching the associated longitudinal end of the unitary magnet 4.
    As shown in Figure 3c, in a magnet structure 10, the unit magnets 4 are directly adjacent to each other by being partially in contact. The unit magnets 4 are glued by depositing glue. The plurality of unit magnets 4 provides a mesh of magnets without interposing holding elements between them other than glue, the unit magnets 4 being in direct contact between adjacent magnets. The first portion 4a and the second portion 4b for a unitary magnet are also shown in this figure 3c.
    In Figure 2, the unit magnets 4 are glued against each other without mesh between them. The same is true for Figure 3c. In FIG. 2, the reference 5 designates the adhesive layer of the magnet structure 10 with the branches 3, this adhesive layer being shown enlarged to be more visible. The adhesive can be a layer of composite, a bonding resin, advantageously thermosetting or thermoplastic.
    The reference 6 designates a space filled with glue between two unit magnets 4, the glue between unit magnets 4 can be similar to the glue of the magnet structure 10 or of a large magnet between two branches 3. Each magnet large size or magnet structure 10 between two adjacent branches 3 can also be embedded in a layer of composite, the rotor 1 also being embedded in a layer of composite in its entirety.
    There may therefore be a superposition of a first layer of composite to surround the unit magnets 4, of a second layer of composite to individually surround the magnet structures 10 and of a third layer of composite to coat the rotor 1.
    As not shown in the figures but by using the references which are already indicated in the figures for similar elements, each magnet structure 10 can integrate at least one mesh having meshes each delimiting a housing for a respective unitary magnet 4. Each housing can have sufficient internal dimensions sufficient to allow a unitary magnet 4 to be inserted into its interior while leaving a space between the housing and the unitary magnet 4 filled with a fiber-reinforced resin, the meshes being made of insulating material. fiber reinforced.
    The hoop 8 can be made of glass fibers or carbon fibers. The composite hoop 8 circumferentially surrounds the magnet structures 10 or the large magnets at an outer periphery of the rotor 1. The hoop 8 contributes, if necessary, to the radial maintenance of the magnet structures 10 or large magnets pruning in addition to that guaranteed by the external composite coating layer. The tapered points 3b of the branches 3 can be joined or not the hoop 8.
    Cover discs, not shown in the figures, can be arranged on each circular face of the rotor 1 to prevent axial movement of the magnet structures 10 or large magnets between two arms 3.
    The invention also relates to a method of manufacturing such a rotor 1, in which the width I of each branch 3 at a point of its length extending radially from the external periphery of the hub 2 to the internal periphery of the hoop 8 at a known distance from the central axis 7 of rotation of the rotor 1 is determined from an evaluation of an admissible mechanical stress capable of being applied to the rotor 1, of a maximum admissible speed of rotation of the rotor 1 and mechanical resistance of the material of the branch.
    A decrease in the width I of each branch 3 away from the hub 2 is obtained by selecting for each branch 3 a width I for each point of its length allowing an iso-stress to be obtained inside the branch 3.
    FIG. 4, also referring to FIGS. 1 and 2, shows for example and without being limiting a curve giving the width I of a branch 3 in millimeters (mm) as a function of a distance from a point r taken in the length of the branch 3 relative to the central axis 7 of the rotor 1, r being expressed in millimeters (mm). This curve is established for a rotational speed of the rotor 1 chosen arbitrarily of 1,400 revolutions per minute or rpm, another speed that can also be chosen, in particular a maximum permissible rotational speed of the rotor 1.
    It is visible that the width I of the branches 3 decreases more r therefore increases away from the central axis 7 of the rotor 1. As it is visible in FIGS. 1 and 2, for which two different points r are shown, the distance from the point r to the central axis 7 of the rotor 1 is between the radius of the hub 2 referenced ri for internal radius and the internal radius of the hoop 8 equivalent to the external radius re of each magnet structure 10 or of each large magnet .
    Advantageously, the width I of each branch at a point of its length extending radially is given by the following equation:
    K being a constant varying according to a thickness of the hoop 8 and representative of the mechanical resistance of the material of the branch, p a density of the magnet or of the magnet structure 10, an admissible mechanical stress capable of being applied on the rotor 1 and consequently on the branch, d'ouverture an opening angle of each magnet or of each magnet structure 10 and W the maximum admissible speed of rotation of the rotor 1.
    The angle θ is visible in FIG. 2. In this FIG. 2 and also in FIG. 1, it is visible that an external face 10b of the magnet structure 10 adjacent to the hoop 8 is of larger dimension than the inner face 10a of the magnet structure 10, which means that there is more magnet surface towards the outer periphery of the rotor 1 than towards the hub 2.
    The invention finally relates to an electromagnetic motor or generator with axial flow comprising at least one such rotor 1, the electromagnetic motor or generator comprising at least one stator carrying at least one winding, the electromagnetic motor or generator comprising one or more air gaps between said at least one rotor 1 and said at least one stator.
    The electromagnetic motor or generator may preferably comprise at least one rotor 1 associated with two stators.
    权利要求:
    Claims (14)
    [1" id="c-fr-0001]
    1. Rotor (1) of an electromagnetic motor or generator having a body comprising an internal hub (2) concentric with a central axis (7) of rotation of the rotor (1), branches (3) extending radially with respect to the central axis (7) of rotation from the internal hub (2) towards a hoop (8) forming a circular external periphery of the rotor (1), at least one magnet or a magnet structure (10 ) being housed in each space delimited between two adjacent branches (3), characterized in that:
    • each branch (3) has a decreasing width (I) moving away from the internal hub (2) to end with a tapered point (3b) against the hoop (8), • each magnet or magnet structure (10) has an increasing width (la) moving away from the internal hub (2) to finish against the hoop (8) surrounding the rotor (1).
    [2" id="c-fr-0002]
    2. Rotor (1) according to claim 1, in which the tapered tip (3b) of each branch (3) is at least twice as wide as a base (3a) of the branch (3) connected to the hub (2 ) internal.
    [3" id="c-fr-0003]
    3. Rotor (1) according to claim 2, wherein the bases (3a) of two adjacent branches (3) are separated by an intermediate portion (9) of the inner hub (2), the intermediate portion (9) being shaped concave rounded towards the axis of the rotor (1), the inner hub (2) having a radius (ri) equal to at least a quarter of a radius of the rotor (1).
    [4" id="c-fr-0004]
    4. Rotor (1) according to any one of the preceding claims, in which the hub (2) and the arms (3) are made of glass fibers cast in resin.
    [5" id="c-fr-0005]
    5. Rotor (1) according to the preceding claim, wherein the hub (2) and the legs (3) are in one piece.
    [6" id="c-fr-0006]
    6. Rotor (1) according to one of the preceding claims wherein each magnet structure (10) consists of a plurality of unit magnets (4) secured by an insulating material reinforced with fibers, each unit magnet (4 ) being of elongated shape extending in the axial direction of the rotor (1).
    [7" id="c-fr-0007]
    7. Rotor (1) according to the preceding claim, in which each unitary magnet (4) of the plurality of unitary magnets (4) is of polygonal shape or each unitary magnet (4) has an at least partially ovoid outline comprising a first portion (4a) forming the body of the unit magnet (4) having a larger section and extending over a greater length of the unit magnet (4) than at least a second longitudinal end portion (4b ) pointing towards an associated longitudinal end of the unitary magnet (4), decreasing in section as it approaches the longitudinal end.
    [8" id="c-fr-0008]
    8. Rotor (1) according to any one of the two preceding claims, in which each magnet structure (10) includes at least one mesh having meshes each delimiting a housing for a respective unitary magnet (4), each housing having sufficient internal dimensions sufficient to allow a unitary magnet (4) to be inserted therein while leaving a space between the housing and the unitary magnet (4) filled with a fiber-reinforced resin, the meshes being made of insulating material fiber reinforced.
    [9" id="c-fr-0009]
    9. Rotor (1) according to any one of the preceding claims, in which each magnet or magnet structure (10) between two adjacent branches (3) is embedded in a layer of composite, the rotor (1) also being coated. in a composite layer.
    [10" id="c-fr-0010]
    10. Rotor (1) according to any one of the preceding claims, in which covering discs are arranged on each circular face of the rotor (1).
    [11" id="c-fr-0011]
    11. A method of manufacturing a rotor (1) according to any one of the preceding claims, in which the width (I) of each branch (3) at a point of its length extending radially from the external periphery of the hub (2) at the internal periphery of the hoop (8) is determined from an evaluation of an admissible mechanical stress capable of being applied to the rotor (1), of a maximum admissible speed of rotation of the rotor (1 ) and of a mechanical resistance of the material of the branch (3), a decrease in the width (I) of each branch (3) away from the hub (2) being obtained by selecting for each branch (3) a width ( I) for each point of its length making it possible to obtain an iso-stress inside the branch (3).
    [12" id="c-fr-0012]
    12. Method according to the preceding claim, in which the width I of each branch at a point of its length extending radially is given by the following equation:

    [13" id="c-fr-0013]
    13. Axial flux electromagnetic motor or generator characterized in that it comprises at least one rotor (1) according to any one of claims 1 to 10, the electromagnetic motor or generator comprising at least one stator carrying at least one winding , the electromagnetic motor or generator comprising one or more air gaps between said at least one rotor (1) and said at least one stator.
    [14" id="c-fr-0014]
    14. Motor or electromagnetic generator according to the preceding claim, which comprises at least one rotor (1) associated with two stators.
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    同族专利:
    公开号 | 公开日
    US20210313853A1|2021-10-07|
    EP3811498A1|2021-04-28|
    JP2021528941A|2021-10-21|
    WO2019243996A1|2019-12-26|
    CN112703660A|2021-04-23|
    FR3083023B1|2021-12-03|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    FR1475501A|1966-04-13|1967-03-31|Deutsche Edelstahlwerke Ag|Permanent magnet poles for permanent magnet systems|
    EP0353042A1|1988-07-26|1990-01-31|The Turbo Genset Company Limited|Axial field electrical generator|
    EP2773023A1|2013-02-27|2014-09-03|Yasa Motors Ltd|Axial flux motor|
    FR3014255A1|2013-12-02|2015-06-05|Renault Sa|DISCOID ROTOR WITH REINFORCED COMPOSITE STRUCTURE FOR AXIAL FLUX ELECTRIC MACHINE|EP3929951A1|2020-06-25|2021-12-29|RENAULT s.a.s.|Method and system for manufacturing magnetic poles|
    FR3064423B1|2017-03-22|2019-11-15|Whylot Sas|ROTOR FOR MOTOR OR ELECTROMAGNETIC GENERATOR WITH ALVEOLAR STRUCTURE COMPRISING ALVEOLES FOR THE HOUSING OF RESPECTIVE MAGNETS|
    FR3107999A1|2020-03-06|2021-09-10|Renault Sas|Rotor for electromagnetic axial flow machine|
    法律状态:
    2019-05-27| PLFP| Fee payment|Year of fee payment: 2 |
    2019-12-27| PLSC| Publication of the preliminary search report|Effective date: 20191227 |
    2020-06-23| PLFP| Fee payment|Year of fee payment: 3 |
    2021-06-14| PLFP| Fee payment|Year of fee payment: 4 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1800691|2018-06-22|
    FR1800691A|FR3083023B1|2018-06-22|2018-06-22|ROTOR FOR ELECTROMAGNETIC MOTOR OR GENERATOR WITH TAPERED BRANCHES|FR1800691A| FR3083023B1|2018-06-22|2018-06-22|ROTOR FOR ELECTROMAGNETIC MOTOR OR GENERATOR WITH TAPERED BRANCHES|
    EP19756243.2A| EP3811498A1|2018-06-22|2019-06-17|Rotor for an electromagnetic motor or generator with tapered branches|
    JP2020564887A| JP2021528941A|2018-06-22|2019-06-17|Rotor for electromagnetic motors or generators with tapered branches|
    CN201980041544.3A| CN112703660A|2018-06-22|2019-06-17|Rotor for an electromagnetic engine or generator with conical branches|
    PCT/IB2019/055036| WO2019243996A1|2018-06-22|2019-06-17|Rotor for an electromagnetic motor or generator with tapered branches|
    US17/056,155| US20210313853A1|2018-06-22|2019-06-17|Rotor for an electromagnetic motor or generator with tapered branches|
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