Classifications

• • 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
  • H02K21/02—Details
  • H02K21/04—Windings on magnets for additional excitation ; Windings and magnets for additional excitation
  • H02K21/042—Windings on magnets for additional excitation ; Windings and magnets for additional excitation with permanent magnets and field winding both rotating
  • H02K21/044—Rotor of the claw pole type
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K15/00—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
  • H02K15/12—Impregnating, heating or drying of windings, stators, rotors or machines

Definitions

• the invention relates in particular to a claw rotor comprising magnetic elements arranged between two adjacent claws for a rotary electric machine, in particular of a motor vehicle.
• a reversible machine is a rotary electric machine capable of working in a reversible manner, on the one hand, as an electric generator in alternator function and, on the other hand, as an electric motor for example for starting the heat engine of the motor vehicle .
• a rotating electrical machine includes a rotor that rotates about an axis and a fixed stator surrounding the rotor.
• alternator mode when the rotor is rotating, it induces a magnetic field on the stator which transforms it into electric current in order to supply the electric consumers of the vehicle and to recharge the battery.
• motor mode the stator is electrically supplied and induces a magnetic field driving the rotor in rotation.
• a claw rotor has two pole wheels, each having a plate and claws extending axially from the plate. Each claw of a first polar wheel partly extends in a space between two adjacent claws of the other polar wheel. Magnetic elements such as permanent magnets can be placed between two consecutive claws of two separate pole wheels. Such elements make it possible to increase the performance of the machine by desaturating the rotor in order to reduce the magnetic losses between the pole wheels and therefore by improving the amount of magnetic flux transmitted to the stator.
• Each magnetic element is held in position by means of lips extending from the claws.
• the vibrations created by the different operating cycles of the vehicle can move the magnetic element.
• the lips are then not sufficient to guarantee the position of the magnetic element.
• the centrifugal force exerted on the magnetic elements is very strong and the claws of the pole wheels can open. This has the effect that the magnetic element is no longer maintained over the entire length of the lip but only on the part of the lip closest to the plate of the pole wheel. The magnetic element is then no longer held in its center and the bending of the said element can cause the latter to break.
• a shim is arranged on an external face of the magnetic element.
• This wedge makes it possible to stiffen the magnetic element while avoiding its bending.
• Such a shim must have dimensions of length and width substantially identical to those of the magnet in order to best correspond to the external face of the magnet and thus ensure its stiffening without increasing the size of the rotor. This leads to manufacturing constraints of the wedge and therefore cost.
• the rotor assembly process is also impacted by the presence of this shim which requires a step of positioning an additional part.
• the present invention aims to avoid the drawbacks of the prior art.
• the present invention therefore relates to a rotor for a rotary electric machine having an axis of rotation and comprising: two pole wheels, each formed by a plate extending radially and a plurality of claws extending from said plate substantially axially, each claw of a pole wheel extending in a space formed between two adjacent claws of the other pole wheel and having an internal surface arranged opposite the axis and an opposite external surface radially to said internal surface; at least one magnetic element disposed between two successive claws each belonging to one of the pole wheels; and at least one armature disposed against an external face of the magnetic element.
• the rotor also comprises an insulating layer extending, at least, in and / or through the armature so as to form a wedge of stiffening and on an external surface of at least one claw adjacent to the magnetic element.
• the insulating layer thus extends inside the frame to form the stiffening shim.
• the stiffening shim is formed of a skeleton composed of the frame and part of the insulating layer, called the secured part, permeating the frame.
• the term "insulating layer” means an electrically insulating layer.
• the stiffening shim ensures the distribution of forces over all the surface of the magnetic element and thus improves its resistance to centrifugation.
• Such a wedge formed of a skeleton soaked in an insulating layer makes it possible both to stiffen the wedge and to bond said wedge to the magnetic element in order to improve its retention.
• this embodiment of the shim makes it possible to simplify the structure of the rotor as well as its precedent. The manufacture of such a rotor is thus less expensive. Indeed, the fact of using a simple reinforcement instead of making a full block allows to reduce the manufacturing constraints of the block and thus its cost. In addition, this makes it possible to avoid having portions of insulating layer which are not useful in the rotor since, in the prior art, the shim is covered with a non-functional insulating layer which does not penetrate inside the down. In contrast, in the present invention, the insulating layer penetrates the reinforcement to form the wedge.
• the external face of the magnetic element is arranged radially opposite to an internal face of said element arranged opposite the axis.
• the insulating layer comprises a secured part extending in and / or through the frame and a free part extending on the external surface of the claw, said insulating layer extending continuously between the part subject and the free part.
• the insulating layer extends continuously from the inside of the frame to the external surface of the claw.
• the insulating layer is thus formed in one piece, a portion of this layer extending in and / or through the reinforcement.
• the frame and the insulating layer are formed of non-magnetic materials.
• the frame is formed of a fibrous structure or of a mesh structure.
• the fibrous structure comprises a fibrous material such as glass fiber or vegetable fiber or ceramic fiber.
• This fibrous material can also be paper or cardboard.
• the grid structure is formed of a support comprising openings such as a grid.
• This structure can be formed of plastic material.
• the insulating layer is also an adhesive layer.
• the insulating layer is formed from a resin or a polymer material.
• the magnetic element is a permanent magnet.
• each claw in contact with the magnetic element comprises a claw body extending axially from the plate and at least one lip extending from said body in an ortho-radial direction so as to maintain the magnetic element.
• the insulating layer extends continuously between the interior of the frame and an internal surface of at least one lip of a claw adjacent to the magnetic element. This makes it possible to stick the stiffening shim to the claw, which improves the centrifugation behavior of the assembly formed by the frame and the magnetic element.
• the magnetic element is disposed radially closer to the axis than the stiffening shim which is itself disposed radially closer to the axis than the lip. This makes it possible to improve the centrifugation behavior of the magnetic element since the stresses exerted on said element are more problematic on its external radial end face than on its internal face.
• the present invention also relates to a rotary electrical machine comprising a rotor as previously described.
• the rotating electric machine can advantageously form an alternator, an alternator-starter, a reversible machine or an electric motor.
• the present invention further relates to a method for producing a rotor of a rotary electrical machine.
• Such a method comprises the following steps:
• a step of producing two pole wheels each formed by a plate extending radially and a plurality of claws extending from said plate in a substantially axial manner and having an internal surface disposed opposite the axis and an outer surface radially opposite said inner surface;
• Such a method makes it possible to simplify the production of the rotor by dispensing with the full-fledged production of a stiffening shim while ensuring good support and good resistance to centrifugation of the magnetic element.
• the first positioning step is preceded by a step of applying an attachment means between the magnetic element and the armature.
• This attachment means is for example glue placed on the magnetic element and / or on the frame.
• the step of arranging the insulating layer is followed by a step of polymerizing the material forming the insulating layer.
• the step of disposing the insulating layer is carried out by dipping the rotor in a bath or by emission via a jet or by localized application via a syringe.
• FIG. 1 represents, schematically and partially, a sectional view of a rotary electrical machine according to an exemplary implementation of the invention
• FIG. 2 represents, schematically and partially, a perspective view of the rotor of FIG. 1,
• FIG. 3 shows, schematically and partially, a perspective view of the rotor of Figure 2 before the application of the insulating layer
• FIG. 4 represents, schematically and partially, a perspective view of an example of reinforcement
• FIG. 5 represents, schematically and partially, a sectional view of a portion of the rotor of FIG. 2, and
• FIG. 6 represents a flow diagram of an example of a method for producing the rotor of FIG. 2.
• FIG. 1 shows an example of a compact and polyphase rotary electrical machine 10, in particular for a motor vehicle.
• This machine 10 transforms mechanical energy into electrical energy, in alternator mode, and can operate in engine mode to transform electrical energy into mechanical energy.
• This rotary electric machine 10 is, for example, an alternator, an alternator-starter, a reversible machine or an electric motor.
• the machine 10 comprises a casing 11. Inside this casing 11, it further comprises a shaft 13, a rotor 12 integral in rotation with the shaft 13 and a stator 15 surrounding the rotor 12. The rotational movement of the rotor 12 takes place around an axis X.
• the axial, radial, exterior and interior designations refer to the axis X passing through the shaft 13 at its center.
• the axial direction corresponds to the X axis while the radial orientations correspond to concurrent planes, and in particular perpendicular, to the X axis.
• the exterior or interior denominations are assessed relative to the same X axis, the internal designation corresponding to an element oriented towards the axis, or closer to the axis with respect to a second element, the external designation designating a distance from the axis.
• the housing 1 1 includes a front flange 16 and a rear flange 17 which are assembled together. These flanges 16, 17 are hollow and each carry, centrally, a bearing coupled to a ball bearing 18, 19 respectively for the rotational mounting of the shaft 13.
• the housing 1 1 includes fixing means 14 allowing the mounting of the rotary electrical machine 10 in the vehicle.
• the stator 15 comprises a body 27 in the form of a packet of sheets provided with notches for mounting an electric coil 28.
• This coil 28 passes through the notches of the body 27 and form a front bun 29 and a rear bun 30 on either side of the stator body.
• the winding 28 is formed of several phases electrically connected to an electronic assembly 36 forming a voltage rectifier bridge.
• a pulley 20 is fixed on a front end of the shaft 13, at the level of the front flange 16. This pulley 20 makes it possible to transmit the rotational movement to the shaft 13 or to the shaft 13 to transmit its rotational movement to the belt.
• the front / rear designations refer to the pulley 20.
• a front face is a face oriented in the direction of the pulley while a rear face is a face oriented in the opposite direction of the pulley.
• the end rear of the shaft 13 carries, here, slip rings 21 belonging to a collector 22. Brushes 23 belonging to a brush holder 24 are arranged so as to rub on the slip rings 21.
• the brush holder 24 is connected to a voltage regulator (not shown).
• the front flange 16 and the rear flange 17 may further comprise lateral openings for the passage of air in order to allow the cooling of the machine by air circulation generated by the rotation of fans 25, 26 on the rotor body.
• the rotor 12 is a claw rotor. It has two pole wheels 31. Each pole wheel 31 is formed of a plate 32 and a plurality of claws 33 forming magnetic poles.
• the plate 32 is of transverse orientation and has, for example, a substantially annular shape.
• This rotor 12 further comprises a cylindrical core 34 which is axially interposed between the pole wheels 31.
• this core 34 is formed by two half cores each belonging to one of the pole wheels.
• the rotor 12 comprises, between the core 34 and the claws 33, a coil 35 comprising, here, a winding hub and an electric winding on this hub.
• the slip rings 21 belonging to the collector 22 are connected by wire connections to said coil 35.
• each claw 33 of the rotor 12 extends axially from the plate 32 and extends in a space, called inter-claw space, formed between two adjacent claws of the other pole wheel. Thus two adjacent claws each belong to a different polar wheel.
• Each claw 33 has an internal surface 43 arranged opposite the axis X and an external surface 44 radially opposite the internal surface 43.
• the inter-claw space accommodates a magnetic element 37.
• These magnetic elements are generally permanent magnets.
• Such permanent magnets are for example formed of rare earth or ferrite or of any other material having similar magnetic properties.
• the inter-claw space also houses a stiffening shim 38 disposed on the magnetic element 37.
• This shim 38 is formed of a armature 39 and a secured part 40 of an insulating layer 41.
• This blocking of stiffening of the magnetic element prevents the latter from being deformed during the rotation of the rotor 12 under the pressure of centrifugal force and thus prevents any breakage of said magnetic element.
• the frame 39 makes it possible to create a support for the subject part 40 of the insulating layer 41 and the subject part 40 makes it possible both to solidify the shim 38 and to glue said shim to the magnetic element 37 to avoid a shift between the two elements during centrifugation.
• the armature 39 is disposed against an external face 44 of the magnetic element 37.
• the external face 44 is arranged radially opposite to an internal face 45 of the magnetic element 37 arranged opposite the X axis.
• the internal and external faces are connected together by lateral faces 46 as well as an upper face and a lower face.
• the stiffening shim 38 extends in a substantially ortho-radial direction plane and can have a shape corresponding to a shape of the external face 44 of the magnetic element 37.
• the armature 39 extends so that its face in contact with the magnetic element 37 follows the shape of said element when the latter is not constrained, that is to say when the rotor is not rotating.
• the frame 39 extends so as to cover at least 30% of the external face 44 of the associated magnetic element 37.
• a length of the frame 39 may be less than a length of the magnetic element 37, the lengths being considered in a substantially axial direction extending between a front face and a rear face of the elements.
• the magnetic element 37 can protrude axially at one of the axial ends of the armature 39 in order to identify the insertion orientation of the assembly formed by the magnetic element 37 and the armature 39 which depends the direction of polarization of the magnetic element.
• the frame 39 is made of a non-magnetic material and preferably electrically insulating.
• the frame 39 is formed of a fibrous structure comprising a fibrous material such as fiberglass or vegetable fiber or ceramic fiber of cardboard or paper.
• the frame 39 is formed of a mesh structure such as a support comprising openings in particular formed of a plastic material.
• the frame is a support comprising microscopic openings in which is housed the secured part 40 of the insulating layer 41; in the second case, the frame is a support comprising macroscopic openings in which is housed said subject portion 40.
• the insulating layer 41 is formed of a fixed part 40 extending in and / or through the frame 39 and of a free part 47.
• the insulating layer 41 is composed of a non-magnetic and electrically insulating material.
• the insulating layer 41 is also an adhesive layer to make it possible to reinforce the mechanical retention of the parts covered with said layer.
• the insulating layer 41 is formed from a resin or a polymer material.
• the free part 47 of the insulating layer 41 extends at least over an external surface 43 of at least one claw adjacent to the magnetic element 37 and in particular adjacent to the frame 39.
• the insulating layer 41 is formed in one piece.
• the subject part 40 and the free part 47 are made of material between them. There is therefore no discontinuity between said parts 40, 47.
• each claw 33 in contact with a magnetic element comprises a claw body 48 extending axially from the plate 32 and at least one lip 49 extending from said body 48 in an ortho-radial direction so as to be opposite the magnetic element 37 disposed in the corresponding inter-claw space.
• the assembly formed by a magnetic element 37 and its stiffening shim 38 is held between two adjacent lips 49, belonging to two claws 33 respective and adjacent to each other, and extending in the same inter-claw space in opposite directions relative to each other. This retention of the magnetic element 37 with lips 49 is particularly advantageous when said element 37 is a permanent magnet.
• the magnetic element 37 is arranged radially closer to the axis X than the stiffening shim
• an inner radial end surface of the lip 49 is in contact with an outer radial end face of the stiffening shim 38 and an inner radial end face of said shim 38 is in contact with the face d external radial end 44 of the magnetic element 37.
• a thin thickness of insulating layer 41 and in particular of free part 47 of said layer may extend between the internal radial end surface of the lip 49 and the external radial end face of the stiffening shim 38.
• the insulating layer 41 extends continuously between the reinforcement
• the insulating layer 41 and in particular the free part 47 of said layer covers all the external surfaces 42 of the claws 33 and extends in and / or through all the frames 39.
• the free part 47 s' extends between the lateral surfaces 49 of the magnetic elements 37 and the claw bodies 48 as well as on the upper, lower and internal faces 45 of said magnetic elements.
• the rotor 12 can comprise several assemblies formed by a magnetic element 37 associated with a stiffening shim 38.
• each inter-claw space can comprise at least one assembly formed by a magnetic element 37 associated with a stiffening shim 38 Alternatively, some inter-claw spaces may not include such a set.
• FIG. 6 illustrates a simplified method of producing the rotor 12 comprising the main steps of mounting the magnetic element 37 in the inter-claw space.
• This production method 50 comprises a step 51 of forming the two pole wheels 31 followed by a first step of positioning 52 of the armatures 39 on the associated magnetic elements 37.
• This first positioning step 52 can be accompanied by a step of applying an attachment means such as glue between the magnetic element and the armature to be assembled together.
• the method 50 then comprises a second step of fitting 53 of the assemblies formed by the armature 39 and the magnetic element 37 on a claw 33 in contact with a lip 49, then a third step of fitting 54 of the second claw 33 to obtain an intermediate rotor as illustrated in FIG. 3.
• the method 50 comprises a step 55 of disposing the insulating layer 41.
• the secured part 40 and the free part 47 of the layer 41 are deposited during the same disposal step 55 to form a layer of continuous material.
• This step is for example carried out by soaking the intermediate rotor in a bath or by emission via a jet or also by localized application via a syringe.
• a step of polymerization of the material forming the insulating layer 41 can be done.
• This disposal step 55 is for example carried out in one go.
• the present invention finds applications in particular in the field of rotors for alternator or reversible machine, but it could also be applied to any type of rotary machine.

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

Applications Claiming Priority (2)

Publications (1)

Family

ID=63834224

Family Applications (1)

Country Status (3)

Family Cites Families (9)

• 2018
  • 2018-07-27 FR FR1857023A patent/FR3084537B1/fr active Active
• 2019
  • 2019-07-25 EP EP19745130.5A patent/EP3830936A1/de not_active Withdrawn
  • 2019-07-25 WO PCT/EP2019/070002 patent/WO2020020993A1/fr unknown

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