Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K1/00—Details of the magnetic circuit
  • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
  • H02K1/22—Rotating parts of the magnetic circuit
  • H02K1/27—Rotor cores with permanent magnets
  • H02K1/2706—Inner rotors
  • H02K1/272—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis
  • H02K1/274—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets
  • H02K1/2753—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets the rotor consisting of magnets or groups of magnets arranged with alternating polarity
• • 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
• • 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
  • H02K2213/00—Specific aspects, not otherwise provided for and not covered by codes H02K2201/00 - H02K2211/00
  • H02K2213/03—Machines characterised by numerical values, ranges, mathematical expressions or similar information

Definitions

• the invention relates to a rotor for an electric machine.
• the invention finds a particularly advantageous, but not exclusive, application with current generators or generators.
• Electrical machines comprising a stator and a rotor with permanent magnets secured to a shaft.
• the rotor may be integral with a driving and / or driven shaft and may belong to a rotating electrical machine in the form of an alternator or current generator as described in document EP 0 803 962 or of an electric motor as described. in EP 0 831 580.
• the shaft can ensure the setting in motion of a scroll compressor, also known as "scroll compressor".
• Such a system comprises two spirals interposed as pallets for pumping and compressing the refrigerant. In general, one of the turns is fixed, while the other moves eccentrically without turning, so as to pump and then imprison and finally compress fluid pockets between the turns.
• the machine comprises a housing carrying the stator. This housing is configured to rotate the shaft for example by means of rolling, such as ball bearings and / or needle.
• the rotor comprises a body made of laminated sheet metal, which comprises housings. Inside some of the dwellings, is positioned at less a permanent magnet. There are tolerances used in the realization of the rotor which make it possible that the magnets are badly plated inside the housing of the rotor; this can be troublesome given the action of the centrifugal force to which the magnets can be subjected. Solutions have been developed to remedy this aspect.
• CN202221930 describes a permanent magnet rotor comprising:
• the problem posed here is to reduce the magnetic flux leakage paths of the rotor without negatively impacting the mechanical strength of the rotor.
• one of the objectives here is to avoid that mechanical stress concentrations that can occur in the vicinity of the housing of the magnet does not adversely affect the life of the rotor because of its operation.
• it is a question of proposing a rotor with permanent magnets, easy to produce, inexpensive, durable and presenting a compromise between the prevention of magnetic flux leakage paths and the mechanical strength of the rotor body.
• the solution proposed by the present invention is that recesses are formed in the body and positioned between the housing on a path successively connecting the protruding portions of the consecutive housing.
• the magnet is held radially and axially by means of a holding device extending axially inside the housing between the inner axial portion of the housing and said axial face of the magnet.
• This holding device advantageously has a spring effect for holding the magnets when it is placed in one of the housings 9. Such an arrangement prevents unwanted sliding of the magnet relative to its housing during operation of the rotor at high rotational speed. Indeed, the spring effect of the holding device makes it possible to object to a force opposing the centrifugal force.
• the concave portions have outer contours formed by lines in an arc.
• the arcuate lines of the outer contours of the concave portions make it possible to progressively refine the thickness of material between the housing and the recess and improve the mechanical strength of the rotor body, in particular in the vicinity of the housing and the recess.
• the arrangement combining the radially projecting portion at greater proximity to the axial face of the magnet than the two concave portions and progressive refinement of the material thickness between the housing and the recess via arcuate lines. allows to answer these two problems and propose a good compromise.
• the projecting portion has a first facet having a medium (M) defining the center of the lines in an arc.
• the arcuate lines of the outer contours of the concave portions have a common circle center.
• the center of the circle is included in a plane passing through the axis (X) and is included radially in the housing.
• the radius of curvature of the arcuate lines is substantially equal to half a width of the housing.
• the recess has two first sides, each of said first sides extending substantially parallel to a radial face of the nearest housing.
• the thickness between the radial face of a housing and the side of a subsequent recess is thinned to limit the magnetic leakage paths.
• the radial face of the magnet is substantially orthogonal to the first facet of the protruding portion.
• the magnet being guided radially by the radial faces of the housing, this advantageously makes it possible to transfer the forces from the protruding portion to the magnet via the first facet; a greater proportion of the stresses is transferred radially into the magnet, which reduces the stresses between the recess and the housing of the magnet.
• the trajectory is circular and centered on the point O, the point O being at the intersection between T'axe of the rotor and the perpendicularly cutting section of the X axis of the rotor.
• the path extends along a maximum length of the recess.
• the path extending along the maximum length of the recess is the length between two consecutive housings.
• the recesses have a shape resulting from the combination of a triangle shape and a trapezoidal shape.
• fourth sides of the triangle shape adjacent to two non-parallel first non-parallel sides of the trapezoidal shape define an angle (a) between 90 ° and 180 ° with respect to the first sides respectively adjacent thereto .
• Such a range of angles offers a good compromise between the reduction of the magnetic leak paths, a saving of material and a good mechanical strength of the rotor.
• a withdrawal portion extending along the axis (X) is arranged at the intersection of a radial face of the housing and an outer axial portion of the housing.
• This withdrawal portion facilitates the incorporation of the magnet via a set of assembly.
• this withdrawal portion can integrate a blade (or laminette) to improve the holding of the magnet in the housing.
• the retaining device has a contact with the projecting portion all along the housing along the axis (X).
• This contact makes it possible to standardize the transfer of forces from the protruding portion to the retaining device.
• the projecting portion is between first edges separating said projecting portion from the two concave portions, said two concave portions being between these first edges and second edges that separate the concave portions of the radial faces of the housing.
• the first facet in a section perpendicularly intersecting the axis (X) of the rotor, the first facet extends parallel to the holding device and the second and third parallels parallel to each other are connected to the concave portion at the location said first edges.
• the housing has a closed contour in a section perpendicularly intersecting the axis of the rotor.
• the recesses are formed in the body and positioned between the housings on a path successively connecting the protruding portions of the consecutive housings, along a cross section perpendicular to the axis of the rotor.
• an alternator comprising a rotor according to a preceding embodiment is also aimed at.
• Figure 1 shows a top view of an embodiment of a permanent magnet rotor according to the invention.
• FIG. 2 shows a perspective view of the exemplary embodiment of the rotor shown in FIG.
• Figure 3 shows a partial top view of the exemplary embodiment of the rotor shown in Figures 1 and 2.
• FIG. 4 shows a view from above of the embodiment of the magnet rotor similar to FIG. 3 in which the distribution of the constraints of the rotor body in the operating state is represented, the distribution of the constraints being deduced from the movements of material represented by different reasons.
• FIG. 5 shows a view similar to that of FIG. 4 in which an exemplary embodiment of a magnet rotor according to a prior art is represented.
• FIG. 6 shows a perspective view of the exemplary embodiment shown in FIG. 1 in which the magnet and the device for holding the magnet are represented prior to their incorporation into the housing.
• Figures 1, 2 show a rotor 1 according to the invention, X axis, having a body 3 fixed to a central hub (not shown) splined at its inner periphery for fixing in rotation on a shaft.
• the body 3 comprises housings 9 intended to receive permanent magnets 14 held radially and axially by means of holding devices 17. More specifically, the rotor 1 is formed by a stack of sheets extending in a radial plane perpendicular to the X-axis. The bundle of sheets forms the body 3 of the rotor 1 and is made of ferromagnetic material.
• the sheets of the body 3 are preferably held by means of rivets axially passing through the rotor 1 through openings 31.
• Recesses 5 are formed in the body 3. According to a preferred embodiment, these recesses 5 have, in plan view (see FIG. 1), a shape resulting from the combination of a triangle shape and a trapeze. The triangle has a common side with the long side of the trapezoid. The recesses 5 make it possible to channel the magnetic flux.
• the body 3 also comprises housings 9 - preferably of substantially parallelepiped shape - intended to receive permanent magnets 14. These housings 9 regularly spaced on the circumference of the rotor and located in the body 3 of the rotor 1, have a longitudinal direction of extension parallel to the axis X and an extension direction extending substantially radially relative to the axis X.
• the housings 9, formed in the body 3, are here preferably and of generally rectangular section.
• the housing 9, in a section perpendicular to the axis X, is through and adapted to allow the passage of the holding device 17; the section of this housing 9 is comparatively larger than the largest section of the holding device 17 perpendicular to the X axis, it being understood that during the mounting, the holding device 17 would be a male part and the passage would be the female part.
• the housings 9 may be closed at one of their axial ends.
• FIG. 6 shows a holding device 17, a central part 19 of which deforms a radial force on the magnet 14 and on an inner axial portion 91a of the housing 9.
• the outer axial portion 91b and internal axial portion 91a the faces respectively oriented radially towards the axis X of the rotor 1 and the opposite side to the axis X of the rotor 1.
• the inner axial portion 91 is facing outwardly of the rotor 1; the outside of the rotor 1 is the radial wall of the rotor 1 furthest from the axis X, the inside of the rotor 1 is the part of the rotor 1 which is relatively closer to the center of the rotor 1.
• the housings 9 are intended to receive each of the elements in the form of a magnet 14 or a plurality of permanent magnets 14 superimposed on each other along one of their longitudinal face to obtain maximum power of the machine.
• the superimposed magnets 14 thus form a column of magnetic elements having a shape complementary to that of the housings 9.
• the magnets 14 can therefore be stacked one on the other in a radial direction to form a column of elements of complementary shape to that of housing 9.
• the magnets 14 may be in rare earth for example based on Samarium-Cobalt (SmCo) or based on Neodymium-Iron-Boron (NdFeB) having a high coercivity and a high degree of remanence and a good temperature resistance. They can also be made of ferrite. Of course, the number of magnets depends on the applications and in particular on the length of the body 3.
• the number may be equal to or less than the number of rare earth magnets. So we can use expensive rare earth magnets to get as close as possible to example of a desired electric power of the machine and complete this with less expensive ferrite magnets.
• the invention makes it possible to use permanent magnets of different shade in order to optimize costs.
• At least one of the magnets may be replaced by a non-magnetic element, for example made of aluminum, of the same shape to obtain the desired power of the electric machine. It is thus formed, in the axial direction, a column of elements stacked on each other and of complementary shape to that of the housing.
• all the housings 9 may therefore contain a plurality of magnets 14 stacked in the radial direction with possibly presence of at least one non-magnetic element.
• at least two diametrically opposed housings 9 are empty. Due to the fact that the column of elements comprises at least a plurality of stacked magnets, the power of the rotating electrical machine can be easily adjusted while keeping the same rotor.
• the rotor 1 may comprise holding devices 17 formed from an elongate metal strip whose width depends on that of the housing 9 in which this strip enters.
• the example of the holding device 17 shown in FIG. 6 comprises a central portion 19 extending axially inside the housing 9 between an axial portion 91 inside the housing 9 and an internal axial face 15 of a magnet. 14, this central portion 19 having a shape such that it deforms a radial force on the magnet 14 and on the inner axial portion 91 a.
• This central portion 19 has a shape such that it deforms, when compressed between the magnets 14 and the inner axial portion 91a, a radial force on each magnet 14 of the housing 9 from the inside to the outside of the rotor 1.
• the holding device 17 also comprise first and second retaining means 30 and 40. These first 30 and second 40 retaining means are carried by said central portion 19 to each of its ends. At the ends 20 of the central portion 19, the holding device extends to form the first and second retaining means. The ends 20 of the central portion 19 are located axially facing the axial ends of the inner axial portion 91a; these axial ends are defined axially at the separation between the inside and the outside of the housing 9.
• the first 30 and second 40 retaining means have hook shapes with a bent portion.
• the first and second retaining means 30 and 40 thus carried by said central portion 19 have shapes such that said retaining means 30 and 40 exert, by deformation, an axial force on lower and lower surfaces 4a and 4b respectively of the body 3 .
• the holding device 17 is an elastic piece in the form of a strip of material, which has a central portion 19 and first and second elastically deformable retaining means 40 for exerting respectively a force radial and axial on the permanent magnets.
• the central part 19 with radial action makes it possible to protect the magnets 14 because they are less sensitive to shocks and vibrations because of this central portion 19.
• the first 30 and second 40 axially acting retaining means also make it possible to protect the 14 magnets and make these even less sensitive to shocks and vibrations.
• the magnets 14 have good resistance to centrifugal force thanks to the holding device 17.
• the central portion 19 and the first 30 and second 40 retaining means catch the play due to the manufacturing tolerances of the housings 9 and the magnets 14.
• the presence of the magnets holding device 17 makes it possible to improve the radial resistance of the magnets without moving them, despite the manufacturing tolerances.
• the holding device 17 may also include a second portion intended to be axially pressed between the magnet 14 and the bottom of the housing 9 (the housing 9 is then closed at one of its axial ends).
• a holding flange may make it possible to ensure the axial closure of the open end of the housing 9 inside which the magnet 14 and its holding device 17 are positioned.
• the holding device 17 has a contact with the projecting portion 41 all along the housing 9 along the axis X.
• This holding flange then forms a bottom end of the housing
• This flange is made of a non-magnetic material having high mechanical rigidity.
• the flange may be aluminum.
• the housing 9 is through and has two flanges of ends at each of the axial ends of the housing 9.
• the at least one element in the form of a permanent magnet 14 is held radially and axially inside the housing 9 between the inner axial portion 91a of the housing 9 and the inner axial face 15 of the magnet 14. shown in Figures 1 to 4, the inner axial portion
• the 91a of the housing 9 comprises two concave portions 42 and a portion protruding 41 extending axially along the axis X.
• the projecting portion 41 is closer to the face 15 of the magnet than the two concave portions 42.
• the recesses 5 are formed in the body 3 and positioned between the housings 9 on a path successively connecting the projecting portions 41 of the consecutive housings 9, preferably in a section perpendicularly intersecting the axis (X) of the rotor 1.
• the recesses 5 are positioned between the housings 9 and formed in the body 3, at the same radial distance as the inner axial portion 91a of the housing 9. Is here understood by recess 5, a free passage of material even in operating state of the rotor 1.
• a housing for incorporating a fixing means is not a recess within the meaning of the present application.
• the trajectory is circular and has for center the point O, the point O being at the intersection between the axis X of the rotor 1 and said cross section perpendicularly the axis X of the rotor 1.
• the trajectory extends along a maximum length L of the recess.
• the maximum length L of the recess is taken to mean the length of the recess 5 extending substantially perpendicular to a radial direction D R originating from the point O and passing through the middle of this length L connecting two ends of the recess. recess 5.
• the concave portions 42 have outer contours formed by lines 43 arcuate. These lines 43 in an arc of the outer contours of the concave portions 42 preferably have a center of common circle.
• the center of the circle (here understood by the center of the lines 43 in an arc) is included in a plane passing through the axis (X) and is included radially in the housing 9; this plane passing through the axis (X) is included radially in the housing 9.
• FIGS. 1 and 2 show a preferred embodiment in which the radius of curvature of the arcuate lines 43 is substantially half of a width I of the housing 9. In FIG. 3, which shows half of the housing 9 (FIG. cut according to its width I, see Figure 3), we see this provision more.
• the recess 5 has a polygonal, circular, elliptical shape or a combination of the aforementioned forms. Conventionally, this recess 5 has a polygonal shape.
• the recess 5 has two first sides 51, each of these first sides 51 extending substantially parallel to a radial face 91c of the nearest housing 9.
• the first side 51 is radially at the same distance from the axis (X) of the rotor 1 as the inner axial portion 91a.
• the concave portion 41 is at the same radial distance from the axis (X) as a portion of the first side 51 so that a thickness e is defined between the first side 51 of the recess 5 and the concave portion 42.
• the concave portion 42 of the housing 9 then extends radially outwardly of the rotor 1 to form the radial face 91c of the housing 9.
• This radial face 91c of the housing 9 may comprise a withdrawal portion 92 extending along the X axis, is arranged at the intersection of a radial face 91c of the housing 9 and the outer axial portion 91a of the housing 9.
• this thickness e between the recess 5 and the housing 9 must be sufficiently thick to ensure good mechanical strength of the magnet 14, but it must be thin to prevent magnetic leakage paths.
• the arrangement of the recess 5 for channeling the magnetic fluxes weakens the mechanical strength of the body 3 but a part of the stresses is advantageously transferred into the magnet 14 so that the forces are transferred radially overall from the inner axial portion 91 a to the outer axial portion 91b; in this way, the transfer of a portion of the forces to the projecting portion 41 and the magnet makes it possible to thin the thickness between the recess 5 and the housing 9 so as to minimize the leakage paths of the magnetic flux.
• fourth sides 52 of the triangle shape adjacent to the non-parallel first sides 51 of the trapezoid shape define an angle (a) between 90 ° and 180 ° relative to the first sides 51 which are respectively adjacent to them.
• the projecting portion 41 may preferably have a first facet 41 1 having a medium (M) defining the center of the lines 43 in an arc.
• the radial face 91c of the housing 9 is substantially orthogonal to the first facet 41 1 of the projecting portion 41.
• FIG. 6 shows an embodiment in which the projecting portion 41 is between first edges separating said projecting portion 41 from the two concave portions 42, said two concave portions 42 lying between these first edges and second edges which separating the concave portions 42 of the radial faces 91c of the housing 9.
• the second edge is radially at the same distance from the axis X as a portion of the first side 51.
• the first facet 41 1 extends parallel to the holding device 17 and the second and third parallel facets 412 of the projecting portion 41 parallel to each other. connect to the concave portion 42 at the location of said first edges.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Permanent Field Magnets Of Synchronous Machinery (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=50288174

Family Applications (1)

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Citations (4)

Family Cites Families (22)

• 2013
  • 2013-07-29 FR FR1357484A patent/FR3009140B1/fr active Active
• 2014
  • 2014-07-16 WO PCT/FR2014/051827 patent/WO2015015084A2/fr active Application Filing
  • 2014-07-16 CN CN201480043271.3A patent/CN105431999B/zh active Active
  • 2014-07-16 EP EP14750573.9A patent/EP3028368A2/fr not_active Withdrawn
  • 2014-07-16 US US14/905,846 patent/US10008891B2/en active Active

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