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
  • H02K1/12—Stationary parts of the magnetic circuit
  • H02K1/14—Stator cores with salient poles
  • H02K1/146—Stator cores with salient poles consisting of a generally annular yoke with salient poles
  • H02K1/148—Sectional cores
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K5/00—Casings; Enclosures; Supports
  • H02K5/24—Casings; Enclosures; Supports specially adapted for suppression or reduction of noise or vibrations
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K2201/00—Specific aspects not provided for in the other groups of this subclass relating to the magnetic circuits
  • H02K2201/18—Machines moving with multiple degrees of freedom
• • 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
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K3/00—Details of windings
  • H02K3/46—Fastening of windings on the stator or rotor structure
  • H02K3/48—Fastening of windings on the stator or rotor structure in slots
  • H02K3/487—Slot-closing devices
  • H02K3/493—Slot-closing devices magnetic

Definitions

• the present invention relates to the field of brushless rotating electrical machines, especially at high speeds, typically more than 10,000 revolutions per minute, and more particularly relates to the reduction of noise and vibrations caused by such rotating electrical machines.
• the vibrations of electromagnetic machines cause noise nuisances that are sometimes unacceptable for normal use, as well as a decrease in reliability.
• US Patent Application US2013057105 is also known relating to permanent magnet rotor motors. and more particularly, methods and systems for reducing noise and gearing torque in motors incorporating a permanent magnet rotor.
• the torque resulting from the magnetic interaction between the rotor and the stator may contain an undesirable torsion undulation, either resulting from the current in the windings, or simply from the interaction of the permanent magnets and the stator, this undulation being present in an engine unpowered, which is known as the relaxing couple or residual (cogging in English).
• the teeth and torque pulses at the motor shaft can be transmitted to other driven equipment.
• the solution proposed in this prior art document relates to an open slot stator core comprising a plurality of slots and teeth, with a ferromagnetic material inside the rotor core configured to focus and direct the flow of a or more of said magnets to a stator tooth close to the ferromagnetic material.
• EP2182218 which has a centrifugal pump whose purpose is to ensure a stable construction without play of the stator so that no vibration, noise or resonance occurs.
• the object of the invention is to reduce the creation and the spatial propagation of the noise emitted by the stator by allowing articulation of the stator teeth relative to the cylinder head with one or two degrees of freedom, in rotation or translation.
• the subject of the invention is an electric machine stator having a plurality of radially extending teeth, supported by an annular yoke radially external to said teeth, at least a portion of the teeth being wound, characterized in that a part at least one tooth has at least one degree of freedom in rotation and / or translation relative to said annular ring.
• at least a portion of the teeth has a single degree of freedom, in rotation, with respect to said annular yoke, the axis of rotation being parallel to the axis of rotation of the machine.
• At least a portion of the teeth has a single degree of freedom, in translation in an axial direction, relative to said annular yoke.
• At least a portion of the teeth has a single degree of freedom, in translation in a radial direction, with respect to said annular yoke.
• the teeth has a first degree of freedom, in rotation, and a second degree of freedom in translation relative to said annular yoke.
• the stator comprises at least one inner tubular ring radially to said teeth in one non-magnetic or saturated magnetic material connecting said teeth.
• this inner tubular ring is discontinuous according to the height of said cylinder head, forming several saturable isthms.
• the inner tubular ring has an axisymmetric revolution geometry but it is possible to make an inner tubular ring having an aperiodic revolution geometry.
• the outer annular yoke has grooves of cylindrical shape s Opening towards said teeth, said teeth having at their end, on the side of said outer annular yoke, a protuberance of cylindrical shape complementary to the cylindrical shape of said flutes.
• said cylindrical shape of said splines is a semi-circular section whose radius of curvature is greater than the radius of curvature of the shape of said cylindrical protuberance of the teeth.
• the complementary shapes open on two opening areas where the flutes form, with the flanks of the teeth, an angle gap of less than 10 °.
• the stator may have several teeth, typically six teeth are illustrated in the present application.
• said protuberance is integrally formed with said tooth.
• said protuberance is completed by at least one sleeve positioned radially between the tooth and the outer annular yoke.
• an additional film of a material having mechanical damping properties is inserted between the sleeve and the yoke.
• the teeth and the yoke are adjusted directly or via a connecting piece, by a sliding contact zone extending in an axial direction, in a tangential plane perpendicular to the median radius of the tooth.
• This contact zone constitutes a sliding line or a sliding surface or a succession of sliding points preserving the degree of freedom in rotation and / or the degree of freedom in translation.
• FIGS. 1a and 1b show a front view of stators according to the invention, respectively with and without electric supply coil;
• FIGS. 2a, 2b and 2c show pairs of views of stators according to variant embodiments of FIG. a first embodiment with angular openings of the flutes, with for each of these figures: on the left a front view of the stator without coil and on the right an enlarged view of the junction between a tooth and the stator ring,
• FIGS. 3a, 3b and 3c show respectively front views and two perspectives of a second embodiment using, between the teeth and the yoke, a material having mechanical damping properties
• FIG. 4 represents a view of an alternative embodiment in which the tubular connecting ring has a non-periodic shape
• FIG. 5 represents a graph of the improvement of the sound emission performance of a machine using the principles described in FIG. the present invention
• FIG. 6 represents a perspective view of a stator according to the invention and according to an exploded view
• FIG. 7 represents a front view of a stator according to the invention in an alternative embodiment.
• FIG. 8 represents two stator views according to an embodiment allowing a degree of freedom in translation of the stator teeth
• FIG. 9 represents two views showing the degrees of freedom allowed by the invention, respectively to the left for the degree of freedom in translation and to the right for the degree of freedom in translation
• FIG. 10 represents two views of a stator. according to the invention and a particular mode for accumulating two degrees of freedom - in rotation and in translation - of the toothed assembly
• FIG. 11 represents two views according to different perspectives, of a particular embodiment of a set toothed according to the invention
• FIG. 12 represents a sectional view showing the amplitude of rotation of the tooth
• FIGS. 13a, 13b and 13c represent the different moments of tooth rotation
• FIG. 14 represents a sectional view according to an alternative embodiment
• FIG. 15 shows a sectional view according to another alternative embodiment.
• Figure la shows a front view of an embodiment of a wound stator according to the invention in a preferred embodiment.
• Figure lb is a view without coil and with a different cylinder head.
• the stator comprises a cylinder-shaped yoke (1) of ferromagnetic material having grooves (2 to 7) extending parallel to the median axis on the inner wall of the cylinder head (1).
• the holes (30) are not significant in the invention and only serve to represent realistically, in this figure la, the means by which the stator can be fixed in one application.
• the section of these grooves (2 to 7) is semi-circular, to allow the pivoting installation of the end of the teeth (12 to 17).
• the radially extending teeth (12-17) are surrounded by electrical coils (24-29), usually made of coiled copper wire or aluminum foil.
• These teeth (12 to 17) are constituted by massive pieces or constituted by stacks of sheets made of a ferromagnetic material, having a rectangular section extended at the rear by a rounded protuberance (35), of rounded section complementary to the section of grooves (2 to 7), to allow a rotation of an amplitude of a few tenths of degrees to a few degrees, for example ⁇ 1 °, relative to a radial median orientation.
• the opposite end, that is to say the inner end, of the teeth (12 to 17) is connected to a tubular connection ring (11) made of a non-magnetic or magnetically saturated material.
• This ring (11) serves to participate in stiffening the mechanical structure of the stator but it is only a variant, although preferred for a reason of mechanical maintenance of the teeth together, not limiting embodiment of the invention.
• This tubular connecting ring (11) may have an asymmetrical configuration, for example with a wall of non-constant thickness or variable stiffness in order to avoid resonance between the teeth (2 to 7). This is illustrated in Figure 4.
• FIGS. 2a to 2c show detailed views of the pivotal connection between the tooth (12) and the tubular yoke (1) in different cases of opening splines.
• the three examples given in FIGS. 2a, 2b and 2c respectively represent openings of 1 °, 5 ° and 10 °, the opening being defined hereinafter.
• the rear protrusion (35) of the tooth (12) has a semi-cylindrical shape with a constant radius of curvature extending for about 180 °. It is engaged in the groove which has a bottom (32) with a radius of curvature constant and complementary to the radius of curvature of the tooth (12), about 180 °.
• This semi-cylindrical part opens on a section (42) forming with the radial plane an opening angle, according to the three example cases shown, to allow the pivoting of the tooth (12), depending on the cases of solicitation and the vibration levels observed.
• the tooth (12) thus has a degree of freedom in rotation.
• the tooth (12) is free to slide around the Z axis at the bottom of the groove (2).
• the clearance between the rear protuberance (35) of the tooth (12) and the bottom of the groove (2) is typically 0.01 millimeters, although this value is not limiting.
• a lubricant film may be provided, although not required, between the rear protuberance (35) of the tooth (12) and the bottom of the groove (2). Similarly, it can be inserted a film of a viscous material having mechanical damping properties.
• FIG. 6 shows the two sets of the stator formed on the one hand by the radial annular yoke (1), itself formed by an assembly of ferromagnetic sheets or by a solid material, and on the other hand by a toothed assembly (100 ) formed teeth (2 to 7) connected to the tubular connecting ring (11).
• This toothed assembly (100) is also formed either by an assembly of ferromagnetic sheets or by a solid material.
• Figures 3a, 3b and 3c illustrate an alternative embodiment, wherein the tooth (12) is engaged in the groove (2) with an additional sleeve (34).
• the groove (2) closes at an angle of about 230 °, without this value being limiting, and ends on either side of the median radial plane by an edge (33) coming to bear against the lateral flank of the tooth (12).
• a different form of contact can be envisaged between the tooth (12) and the yoke (1) depending on the desired mechanical strength.
• a viscous material having mechanical damping characteristics. It may be envisaged to charge the film with ferromagnetic particles, or even to make this film of a flexible ferromagnetic material, in order to minimize the losses of magnetic performance by minimizing the residual air gaps.
• FIG. 3b shows an example of construction of a stator according to this embodiment where the sleeves (34) are two in number per tooth and are slid on both sides on the semi-tubular protuberances (35) during the mounting.
• the damping film can thus be inserted after positioning a sleeve, the second sleeve (34) serving to distribute by piston effect, the damping film.
• FIG. 5 typically shows the improvements obtained in terms of sound emission, in decibels, of an electric machine according to the invention, noted (B), according to a rotation speed increased linearly, and compared to a similar machine (size, identical thickness and mechanical properties) not benefiting from the features of the invention, noted (A). If punctually, for some isolated speeds, some peaks show a degradation of the noise emissions, the average level is largely diminished on the whole diagram realized. At speeds above 80,000 rpm, the improvement is greater than 5 dB.
• Figure 7 shows an alternative version that does not have a tubular connecting ring (11).
• this version is envisaged and may be proposed depending on the application, the main object of the invention residing in the possibility pivoting of the stator teeth.
• Figure 8 shows an embodiment allowing a degree of freedom in translation of the tooth (12) in the groove (2) which is here recessed, radially, relative to the position of the tooth (12). In this way, the protuberance (35) of the tooth (12) slides radially inside the groove (2). More particularly, with reference to the reference (R, ⁇ , Z) drawn in FIG. 8 and centered on the center of the cylindrical protrusion (35), the tooth (12) is free to slide along the axis R, towards the bottom of the groove (2).
• the outer annular yoke (1) has a tooth base (32) recessed, radially, with respect to the tooth protuberance (35) to allow translation of the tooth (12), and a opening section (42) forming with the radial plane an opening angle, to allow the pivoting of the tooth (12).
• the tooth (12) can pivot and translate through the supports (110) of the annular yoke (1) at the junction between the opening section (42) and the tooth base (32). More particularly, with reference to the reference (R, ⁇ , Z) drawn in FIG. 10 and centered on the center of the cylindrical protuberance (35), the tooth (12) is free to slide around the Z axis, on the supports (110) and to translate along the axis R towards the bottom of the groove (2).
• FIG. 11 shows an alternative embodiment of the toothed assembly (100) in which the inner tubular ring (11) is not continuous, forming magnetically saturable isthms (120) on the height of the toothed assembly ( 100).
• This is for example possible by alternating plates of different profiles when this toothed assembly (100) is made with a package of sheets.
• the advantage of this embodiment is possibly to allow a reduction of the magnetic short circuit between each tooth of this toothed assembly.
• the number of isthmus (120) is not fixed.
• FIG. 12 shows the amplitude (18) of rotation of the tooth (12), on either side of the median position, by means of the dashed lines, relative to the center defined by the two reference axes (19). , 20).
• the rear protuberance (35) of the tooth (12) and the bottom (32) of the groove have a similar radius which constitutes, at an angle close to 180 °, a sliding surface.
• the center of these rays is visualized by the intersection of the axes (19, 20).
• This tooth rotation is temporally detailed through FIGS. 13a, 13b and 13c.
• FIG. 13a shows the tooth (12) which has been rotated in the clockwise direction and which comes here, but in a nonlimiting manner, close to the open section (42).
• Figure 13b shows the tooth (12) having undergone a rotation in the counterclockwise direction and which comes here, but without limitation, near the section (42) open.
• Figure 13b shows the tooth in a middle position where the tooth is not excited or moving from one position to another.
• FIG. 14 shows an alternative embodiment where the rear protrusion (35) of the tooth (12) has a radius similar to that of the groove (2) but the tooth is not in contact with the groove, generating an air gap (21). ) between the tooth (12) and the yoke (1).
• the mechanical contact between the yoke (1) and the teeth (12) is achieved by means of the tubular ring (11) and the contact connection of one or more other teeth with the cylinder head (1). ).
• FIG. 15 shows an alternative embodiment where the rear protuberance (35) of the tooth (12) has a non-constant radius in order to present two minimal sliding surfaces on either side of the median axis (20) of the tooth. (12).
• This embodiment makes it possible to minimize the sliding surfaces and thus to minimize friction and mechanical losses.

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

Applications Claiming Priority (3)

Publications (1)

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• 2017
  • 2017-03-31 FR FR1752821A patent/FR3064835B1/fr active Active
  • 2017-08-24 FR FR1757839A patent/FR3064838B1/fr active Active
• 2018
  • 2018-03-29 JP JP2019553860A patent/JP7428517B2/ja active Active
  • 2018-03-29 KR KR1020197030038A patent/KR102590592B1/ko active IP Right Grant
  • 2018-03-29 CN CN201880028619.XA patent/CN110679062B/zh active Active
  • 2018-03-29 EP EP18722104.9A patent/EP3602737A1/de active Pending
  • 2018-03-29 WO PCT/FR2018/050766 patent/WO2018178576A1/fr active Application Filing
  • 2018-03-29 US US16/498,661 patent/US11264846B2/en active Active

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