FR3019950A1 - ELECTRICAL MACHINE WITH OVERLAPPED AND FIXED OR MOBILE RELEASED COILS. - Google Patents

Abstract

An electric machine with superposed and staggered fixed or moving coils, comprising two parts of which a first part P1, including a magnetized structure comprising parallel elements A1-An of opposite polarity, is subject to displacements in a direction X relative to the second P2 part comprising three windings E1, E2, E3 mounted on a non-magnetic support, so as to achieve with the magnetized structure an air gap in which turns of the windings E1, E2, E3, the conductors of the windings E1, E2, E3 being arranged meander, which meanders are staggered regularly along their axis of symmetry and contained in a surface substantially parallel to the elements of the magnetized structure, the width of each of the parallel elements of the magnetized structure being equal to twice the width of the conductors of a winding.

Description

The present invention relates to an electric machine with superposed and staggered fixed or moving coils. It applies in particular but not exclusively to the field of electromagnetic induction actuators and, in addition, to the field 15 of electromagnetic induction generators. In general, it is known that conventional rotating electrical machines comprise a rotor or armature in relative motion in magnetic fields created by the stator or inductor. 20 There are two categories of rotating machines: ® induction machines, ® collector machines. As regards the first category, the inductor or stator, always supplied with alternating current, produces a rotating field which induces in the short-circuit rotor (or squirrel cage) currents which, by interaction on the stator field, generate a motor torque. The speed of the motor is related, inter alia, to the frequency of the alternating current and to the number of poles of the stator; which stator can be supplied with three-phase current, or single-phase current by adding a phase-shifting element in order to allow the induction motor to start. Regarding the second category, the inductor comprises pole pieces 5 supporting either excitation windings or permanent magnets which have a remanent induction. Thus, at the level of the inductor, the magnetomotive force which results from the passage of the current in the excitation windings produces the main flow which runs through the entire magnetic circuit. The magnetic circuit of the armature consists of a stack of laminations cut so as to obtain grooves in which the induced winding will be housed, and is subjected to the inductive magnetic flux of the inductor. The inductive magnetic circuit and the induced magnetic circuit are separated by an air gap which is also part of the magnetic circuit of the machine. Finally, the rotor has a rectifier of the induced alternating currents 20, called a collector, in the case of a generator, or allows DC power to be supplied to the armature, in the case of a motor. In order to improve the mechanical performance of the engine, particularly in terms of rapid variations in the speed of rotation, it is possible to reduce the inertia of the armature by giving it a large elongation (important ratio between the length and the diameter); it is also possible to give the armature the shape of a thin disk and thus eliminate the rotor iron, the active conductors then being radial. Apart from these solutions, essentially applicable to small electric motors intended in particular for servomechanisms, the classic motors -3 have the disadvantage of lack of torque with respect to their volume, the active conductors to be concentrated in a small space, close to the rotary axis.

Electromagnetic induction motors are now known in which the rotating mobile part corresponds to the external inductive part which then constitutes the rotor, while the internal coiled axial part is fixed and constitutes the stator.

Such a structure requires air gaps of large thickness to accommodate the wound conductors of the stator; the implementation remains delicate and may affect the electromagnetic efficiency of the proposed structure. Electromagnetic induction motors are also known, close to the preceding general structure, in which the fixed internal axial portion constituting the stator comprises a series of thin flat plates between which the excitation or armature conductors are deposited. conductors having active portions extending substantially radially or parallel to the axis of the motor; the outer rotational yoke constituting the inductive portion comprises a plurality of magnetic magnet riders disposed in a plurality of angular sectors; thus, according to one embodiment, the magnetic circuit circulates in a radial half plane and comprises two air gaps traversed by a radial magnetic flux.

Such a structure is also difficult to implement because of the volume limitation available for the winding of the armature; in addition, it requires the addition of a piece ensuring the precise and regular positioning of the sheets; this piece, of complex realization, significantly affects the manufacturing costs of such a structure.

In general, it is known that electric motors or generators operate in magnetic field absorption; indeed a pole, created magnetically, for example a stator, will attract vis-à-vis himself a pole opposite name of the rotor so as to absorb the largest amount of flux generated by this pole; this explains the complexity of the windings, the increase of the iron, and consequently of the weight. To this end, it should be noted that the essential handicap prohibiting the industrial development of the POIRSON dynamo is due in large part to the unipolar structure of this machine prohibiting the series setting of the conductors that could equip it to replace the mass cylinder. who constituted it. The electromotive force is limited to a small value, the induction is indeed limited because of the saturation of the mass cylinder, reduced to a thin disc, placed in the gap of an electromagnet in the case of the BARLOW wheel, or in a magnetic carcass, carrying inductive windings in the case of the POIRSON dynamo.

On the other hand, the current delivered can reach high values, provided that sufficiently sized sliding contacts are available; the periphery of the armature being equipotential, it will therefore be covered with a maximum of brushes.

The invention more particularly aims to overcome these disadvantages by providing a structure of electrical conductors arranged in interleaved bundles and juxtaposed to each other; this structure of electrical machines only responds to the laws of Forces LAPLACE, LORENTZ, and are in the continuity of the BARLOW wheel or the dynamo POIRSON. In view of the elements cited, another approach, proposed by the applicant, led to a structure of the electric actuator device or electrical generator reacting to the magnetic repulsion force; this approach consisted in arranging a plurality of pairs of opposing poles, each pair of poles being carried by the same magnetic bar, close to copper conductors traversed by currents of opposite direction under their respective pole; this requires for winding such a circuit with a single electrical conductor to shift a magnet pitch the direction of passage of the conductors between the successive sheets.

Because the poles are discrete and successively alternated, the current in the conductors must be inverted by switching to ensure a given direction of rotation. Thus, in a cyclic DC machine, each elementary conductor moves in a normal induction periodically varying with time; the electromotive forces generated are also periodic, and by the artifice of the collector, a substantially constant electromotive force is collected between the brushes.

One can also imagine moving the drivers at a constant speed and in constant induction; the electromotor field will then be constant; it will be the same with the electromotive force; this is the principle of the BARLOW wheel and the POIRSON dynamo.

The present invention relates to an electric machine with superposed and staggered fixed or moving coils. To this end, it proposes an electric machine with superposed and staggered fixed or moving coils comprising two parts of which a first part, including a magnetized structure comprising parallel elements of opposite polarity, is subject to relative displacements with respect to the second part. part comprising at least three windings mounted on a non-magnetic support, so as to produce with the magnetized structure an air gap in which turns of the windings pass, the conductors of the windings being arranged in a meander composed of U chained, which meanders are offset according to their axis of symmetry and contained in a surface substantially parallel to the elements of the magnetized structure, the width of each of the parallel elements of the magnetized structure being equal to twice the width of the conductors of a branch of the U chained winding, terminals of the windings being connected connected to a switched power source in the case of actuator-type operation, the first portion being mechanically coupled to an actuator in the case of generator-type operation, which produces a switched current across the winding .

The conductors of the windings may be made of metal material such as copper, silver, aluminum, iron, or any other metal alloy comprising among others, the metals mentioned above. They may also be made of a material comprising a conductive element associated with an insulating support such as a plastic.

For this purpose, the electric machine with superposed and shifted fixed or moving coils according to the invention comprises: a configuration of pairs of magnets and magnetic parts generating a magnetic flux as uniform as possible and of significant value, which pairs of magnets of opposite polarity, in particular during their linear displacement or in rotation, are placed vis-à-vis and remain vis-à-vis superimposed and offset coils, the latter being fixed in this case and, conversely, a configuration of pairs of magnets and magnetic parts generating a magnetic flux that is as uniform as possible and of great value, which pairs of magnets of opposite polarity are placed facing each other and remain opposite the superimposed and shifted coils, these being mobile in this case, a configuration of superimposed and offset coils for placing in the flow of magnets the maximum of conductive strands using the more possible surface traversed by the flux over a large thickness, so as to have a large volume of copper or any other electrical conductor and thus reduce losses by Joule effect, a current synchronization taking into account the position of conductors of the windings relative to the magnets in the case of an actuator type operation. Of course, the electric machine described above may be of rotary type or linear displacement type.

In a first embodiment where it is of rotary type, the magnetized structure can be rotatably mounted coaxially on a fixed hollow axis, the external magnetized structure constituting an outer rotor of a motor or a generator; the coils are fixed, integral with the fixed hollow axis, constituting an internal stator; the current leads are located on either side of the fixed hollow axis; moreover, the rotary type structure may be substantially cylindrical, the magnetic flux passing through the coils being radial, or substantially annular, the magnetic flux passing through the coils being axial.

In a second embodiment where it is of rotary type, the magnetized structure can be mounted coaxially, the external magnetized structure constituting a fixed external stator of a motor or generator, the internal magnetized structure movable around a solid axis; the coils are movable around the solid axis and constitute the internal rotor; the -8 current feeds are made via a rotating manifold integral with the inner rotor. In a third embodiment where the electric machine is of linear type, the magnetized structure is movable, integral with a carriage mounted on slides; the coils are fixed and extended over the entire length of movement of the carriage. In this third embodiment, the magnets are mounted in pairs; a pair of magnets is mounted on an iron structure in the form of a cylinder or ring in the case of the rotary type, or in the form of a plate in the case of the linear type. Advantageously, this iron structure may be segmented so as to reduce the metal mass and magnetic leakage. As for the magnets, they are preferably identical so as to avoid saturation and reduce manufacturing costs. The configuration of the coils makes it possible to occupy the maximum of the flow area; the windings can be made from copper or any other electrically insulated flat conductor, thereby reducing eddy currents. The coils may also be made from an electrically insulated flattened ferromagnetic material; this solution makes it possible to better channel the field lines and to increase its value by reducing the gap; nevertheless, the electrical conductivity of this type of winding is lower. Advantageously, the width of a magnet occupies twice the width of the conductors of a branch of the chained U of the winding, the length of the conductors of a branch of the chained U of the winding being equal to the length of the magnet. Thus on the opposite side of the magnet, the magnetic flux is brought back by iron above the conductors of the coil. Thus the pair of poles of opposite polarity covers the width of a meander of a winding; the configuration of the winding makes it possible to occupy the maximum possible area subjected to the flux of the poles.

The Lorentz-Laplace type forces are therefore almost constant during the overflight of the coil width; it is then necessary to switch the current in the next coil so that the force remains in the same direction on the second coil and to switch the current identically on the third coil during the overflight of the pair of poles. Moreover, the synchronization of the current control in the coils must be carried out according to the relative magnet / coil position, so that the Lorentz-Laplace forces are always in the same direction. Advantageously, the current control can be obtained from bridge switches (bipolar or MOS) or any other electrical switch; synchronization can be performed by means of an optical sensor, a Hall effect sensor, or any other conventional sliding contact solution; the accuracy of the detection in position must be of the order of the width of a conductor of the coil. In the case of a mechanical synchronization with brushes, this solution can also allow power switching. The advantages of the structure previously described according to the invention are as follows: a simplicity of implementation thanks to the absence of laminating sheets, since there is no iron swept by a flow, so no variable flow; the iron that carries the magnets works with almost constant flux; a very simple dimensioning because based on the Lorentz-Laplace forces under all-or-nothing flow; an almost constant torque at low rotational speed; a very high power density due to the absence of iron in the stator; a very low inductance due to the structure of the coils and the absence of iron, which allows very rapid variations in current and therefore torque; a reversible operation in generator configuration.

Note however that the part consisting of the coils must be sufficiently rigid so as to resist the engine or generator torque. One embodiment will be described below, by way of non-limiting example, with reference to the accompanying drawings in which: Figure 1 is a schematic representation of the relative arrangement of the three windings shown separately according to the invention, the FIG. 2 is a schematic representation of the disposition of the three windings in the case of a toric structure according to the invention, FIGS. 3a, 3b are a schematic representation of the windings in the case of a toric structure, FIG. 1 is an axial section of a first embodiment of a rotating electrical machine, FIG. 5 shows an axial section of a second embodiment of a rotating electrical machine, and FIG. a third embodiment of a rotating electrical machine. In the example shown in Figure 1, the three windings are shown separately and arranged, for each of them, vis-à-vis a magnetized structure; it comprises: a magnetized structure P1 comprising a series of parallel magnetic elements; the magnets Al, A3, .. are of the same polarity; the magnets A2, A4, ..., are of the same polarity, which is opposite that of the previous magnets. a structure P2 comprising three windings El, E2, E3, the conductors of the windings being arranged in a meander, which meanders are offset along their axis of symmetry X and contained in a surface substantially parallel to the parallel elements Al-An, of the magnetized structure Pl. The windings El, E2, E3 are shown separately in FIG. 1 for a better understanding of their relative position; in fact, these three windings are superimposed in the same plane, in order to constitute the structure P2. The meanders of the windings E1, E2, E3, respectively consist of U chained, the arms of the U are parallel to the lengths of the magnets Al-An. The width of each of the parallel elements of the magnetized structure P1 is equal to twice the width of the conductors of a winding of the structure P2; if L is the width of an arm of the U of the winding, the total width of a U of the winding is 4L, the pitch of a meander winding is 6L; the width of a magnet is 2L and the pitch between two consecutive magnets 30 is 3L. If L is the width of an arm of the U of the winding, the thickness of the U arm of the winding is a significant fraction of the width L; the arm of the U of the winding thus constitutes a flat-shaped electrical conductor of width L and of thickness less than L.

Thus, in this configuration, the Lorentz-Laplace type forces are almost constant during the overflight of the windings El and E3, the currents flowing in these windings El, E3, being of opposite direction; the Lorentz-Laplace type forces are maximum inside the windings and cancel out outside the windings E1, E3. As for the current flowing in the winding E2, it is a question of inverting the current so that the Lorentz-Laplace type forces remain in the same direction during the overflight of the winding E2.

Overflowing windings El, E2, E3, constituting the structure P2, is effected by a relative displacement with respect to the magnetized structure P1, the structure P2 being fixed with respect to the mobile structure P1, or conversely the structure P2 being mobile relative to the fixed structure Pl.

Advantageously, the Al-An magnets will have a strong residual magnetization, of the samarium / cobalt or neodymium / iron / cobalt type, or else. Advantageously, the conductors of the windings E1, E2, E3 will be in the form of flat copper or any other insulated non-magnetic or magnetic electrical conductor. In the example shown in Figure 2, the parts P1 and P2 are arranged in a circular structure; the three windings El, E2, E3 are superimposed and offset in the shape of a torus constituting part P2; likewise the Al-An magnets constitute the toroidal portion P1. In the example shown in Figures 3a, 3b, the windings El, E2, E3, in the case of a circular structure of the rotary electric machine shown in Figure 2, are arranged on either side torus constituting part P2.

According to FIG. 3a, the fold zone Z is located inside the torus; according to Figure 3b, the fold zone Z is located outside the torus. In the example shown in FIG. 4, a first embodiment of a rotary electrical machine is indicated in axial section.

The rotating machine comprises a first so-called external magnetized structure consisting of a non-magnetic outer bell-shaped cylindrical carcass R1 supporting, in the vicinity of its cylindrical inner surface, a cylindrical magnetic plate Fel, which is secured to magnets: Al-An , represented by the symbol A; which are arranged equidistantly on the inner face of the cylindrical magnetic plate Fel. The carcass R1 consists of an outer cylindrical bell 7, closed by a flange 8; which flange 8 is integral, in the vicinity of its central part, a second closed internal bell-shaped structure, which consists of a cylinder 9, integral with the flange 8, a flange 10 and a flange 11 ; these two flanges 10 and 11 support in the vicinity of their outer periphery, a second cylindrical magnetic plate Fe2. These two bell-shaped structures are made integral with each other in the vicinity of the inner surface of the flange 8 and the outer surface of the cylinder 9; they are also rotatably mounted around a hollow cylindrical shaft 1, of central axis X1, by means of three ball bearings, respectively 6 in the vicinity of the inner surface of the flange 7, 12 in the vicinity of the inner surface of the cylinder 9 and 13 in the vicinity of the flange 11. The shaft 1 comprises a flange 2, located between the flanges 7 and 11; the flange 2 supports a non-magnetic cylindrical plate 3, which is supported, in the vicinity of its opposite end, by a flange 4. -14- This structure, consisting of elements 2, 3, 4, in the form of an intermediate bell, is integral of the shaft 1 and is rotatably mounted by a ball bearing 5, which is situated in the vicinity of the inner surface of the flange 4 and the outer surface of the cylinder 9.

The nonmagnetic cylindrical plate 3 supports, in the vicinity of its outer surface, the nested coils E. Thus, on either side of the elements 3 and E, there are two air gaps, respectively EF1, between the coils E and the magnets A. arranged equidistantly on the inner face of the cylindrical magnetic plate Fel, and EF2, between the inner face of the non-magnetic cylindrical plate 3 and the outer face of the cylindrical magnetic plate Fe2. The elements 7, 8, 9, 10, 11, Fel, Fe2, and A, constitute a mobile part P1 with respect to the elements 1, 2, 3, 4, and E, constituting a fixed part P2.

Thus, the power supply of the coils E, not shown, is simplified, not requiring rotating contacts; the cylindrical carcass R1 cylindrical outer bell form an external rotor of an actuator or a rotary generator.

In the example of Figure 5, a second embodiment of a rotary electrical machine, is shown in an axial section. The rotating machine comprises a first so-called external magnetized structure consisting of a non-magnetic cylindrical bell-shaped frame R2 supporting, in the vicinity of its two internal surfaces, two annular magnetic plates Fel, Fe2, which are secured to magnets: An, respectively represented by the symbols A1 and A2; which are arranged equidistantly on the inner faces of the annular magnetic plates Fel, Fe2.

The carcass R2 consists of two pans 3 and 5, supporting in the vicinity of their outer periphery, a cylindrical plate 4. This outer bell-shaped structure is rotatably mounted around a hollow cylindrical shaft 1, axially central X2, thanks to two ball bearings, respectively 6 in the vicinity of the inner surface of the flange 3, and 7 in the vicinity of the inner surface of the flange 5.

The shaft 1 comprises a flange 2, located between the flanges 3 and 5; the flange 2 supports in the vicinity of its outer periphery, vis-à-vis the magnets, symbol A1 and A2, nested coils E located on either side of the spill 2. Thus, on both sides of the flange 2, two air gaps, respectively EF1, are formed between the coils E and the magnets A1 arranged equidistantly on the inner face of the annular magnetic plate Fel, and EF2, between the coils E and the magnets A2 arranged in a equidistantly on the inner face of the annular magnetic plate Fe2.

The elements 3, 4, 5, 6, 7, Fel, Fe2, Al, and A2 constitute a mobile part P1 with respect to the elements 1, 2 and E, constituting a fixed part P2. Thus, the power supply of the coils E, not shown, is simplified, not requiring rotating contacts; said outer bell-shaped cylindrical housing R2 constitutes an external rotor of an actuator or a rotary generator. In the example of FIG. 6, a third embodiment of a rotary electrical machine is shown in section axial.

The rotating machine comprises a first so-called external magnetized structure consisting of a non-magnetic outer bell-shaped cylindrical carcass R3 supporting, in the vicinity of its internal surface, a cylindrical magnetic plate Fel, which is secured to magnets: Al-An , represented by the symbol A; which are arranged equidistantly on the inner face of the cylindrical magnetic plate Fel. The carcass R3 consists of an outer bell 2 closed in the vicinity of its opposite end by a cylindrical flange 3. This outer bell-shaped structure is mounted around a rotor R consisting of a shaft 1 , of central axis X3, thanks to two ball bearings, 5 respectively 4 in the vicinity of the inner surface of the bell 2, and 5 in the vicinity of the inner surface of the flange 3. The shaft 1 supports in the vicinity of its periphery external, vis-à-vis magnets, symbol A, a cylindrical magnetic plate Fe2, which supports in the vicinity of its outer periphery, a non-magnetic cylindrical plate 6, which constitutes the support of nested coils E. Thus, is constituted an air gap EF between the coils E and the magnets A arranged equidistantly on the internal face of the cylindrical magnetic plate Fe 1.

The elements 2, 3, 4, 5, Fel, A, constitute a fixed portion P1 with respect to the elements 1, Fe2, 6 and E constituting a mobile part P2. The power supply of the coils E, not shown, is achieved by sliding contacts not shown; the outer bell-shaped cylindrical carcass R3 constitutes an external stator of an actuator or a rotary generator. Advantageously, the relative positioning of the portion P1 with respect to the windings E1, E2, E3 of the portion P2 comprises a position sensor of the optical type or of the magnetic type or of the Hall effect type or of the potentiometric type. Advantageously, the power supply of the windings El, E2, E3 comprises a current control consisting of bridge switches. Advantageously, the power supply of the windings El, E2, E3 comprises a current control consisting of sliding contacts. This third embodiment of a rotating electrical machine, described above, is undoubtedly the most advantageous representation of an electric machine with superposed and staggered fixed or moving coils. Advantageously, if one considers instead of the rotor R, a non-magnetic plate supporting in the vicinity of its outer surface, a magnetic plate, which, in the vicinity of its outer surface a non-magnetic plate which supports the nested coils, this assembly constitutes a fixed bench of a linear electric machine. Likewise, a non-magnetic, U-shaped plate which supports, in the vicinity of its inner surface, a magnetic plate which supports, in the vicinity of its inner surface, magnets A arranged in an equidistant manner, this assembly constitutes a moving carriage of the linear electric machine. Of course, the invention is not limited to the examples which have just been described. 20

Claims (15)

REVENDICATIONS1. Electric machine with superposed and staggered fixed or moving coils, characterized in that it comprises two parts of which a first part (Pl), including a magnetized structure comprising parallel elements (Al-An) of opposite polarity, is subject to displacements. relative, in a direction (X), relative to the second portion (P2) having three windings (E1, E2, E3) mounted on a non-magnetic support (3), so as to achieve with the magnetized structure a gap (EF ) in which turns of the windings (El, E2, E3) pass, the conductors of the windings (El, E2, E3) being arranged in meander, which meanders are regularly offset along their axis of symmetry and contained in a surface substantially parallel to the elements of the magnetized structure, the width of each of the parallel elements of the magnetized structure being equal to twice the width of the conductors of a winding. 2. Machine according to claim 1, characterized in that terminals of the windings being connected to a switched electrical power source in the case of an actuator-type operation, said first part being mechanically coupled to an actuator in the case of a generator-type operation, which produces a switched current across the winding. 3. Machine according to claim 1, characterized in that the first portion (P1) is movable and the second portion (P2) is fixed. 4. Machine according to claim 1, characterized in that the first portion (P1) is fixed and the second portion (P2) is movable. 5. Machine according to claim 1, characterized in that the first part (Pl) comprises magnets (Al-An) with strong remanent magnetization, preferably of the samarium / cobalt or neodymium / iron / cobalt type. 6. Machine according to claim 1, characterized in that the second portion (P2) comprises conductors in the form of flat copper or any other non-magnetic or magnetic insulated electrical conductor. 7. Machine according to claim 1, characterized in that it comprises means for positioning the portion (P1) relative to the windings (E1, E2, E3) of the part (P2) which comprise a position sensor of the type optical or magnetic type or Hall effect type or potentiometric type. 8. Machine according to claim 1, characterized in that the power supply of the windings (El, E2, E3) comprises a current control consisting of bridge switches. Machine according to claim 1, characterized in that the electrical supply of the windings (E1, E2, E3) comprises a current control consisting of sliding contacts. 10. Machine according to claim 1, characterized in that the two parts (P1, P2) are coaxial and constitute an actuator or a rotary generator. 11. Machine according to claim 1, characterized in that the aforesaid two parts (P1, P2) are contained in parallel planes and constitute an actuator or a linear generator. 30-20- 12. Machine according to claim 10, characterized in that the actuator or the rotary generator comprises three windings (El, E2, E3) three-phase. 13. Machine according to claim 10, characterized in that the actuator or the rotary generator comprises an outer rotor (R1, R2). 14. Machine according to claim 13, characterized in that the outer rotor (R1, R2) comprises a carcass of cylindrical shape (7, 8) or annular shape (3, 4, 5). 15. Machine according to claim 10, characterized in that the actuator or the rotary generator comprises an inner rotor (R).