FR2912565A1 - Linear or rotative type direct current electric machine e.g. motor, for bicycle, has winding terminals fixed to current source during driving type operation, and fixed and movable parts coupled to actuator during dynamo type operation - Google Patents

Abstract

The machine has a fixed part including a magnetized structure (1) with two parallel elements e.g. wings (3, 4), with opposing polarity, and a movable part (5) including windings (9, 10) mounted on a ferromagnetic or steel rectangular framework (6). A driving axle of the windings is situated in an air-gap parallel to the elements and perpendicular to a displacement relative axis of the parts. Terminals of the windings are connected with an electric current source in case of a driving type operation. The parts are coupled to an actuator in case of a dynamo type operation.

Description

The present invention relates to a DC electric machine

  without current switching, this machine can constitute an electric motor or a dynamo and be of linear or rotary type.

  More particularly, it relates to an electric machine of this type according to which: in engine operation, it exploits the Laplace force exerted between one or more conductors traversed by a current I placed in a magnetic field (or flux); dynamo operation the (or) conductor (s) are subject to a relative displacement with respect to the magnetic field, through a supply of mechanical energy, so as to cause a scan of (or) conductor (s) in the magnetic field (or flux). We then obtain at the terminals of the (or) conductor (s) a voltage from the Lorentz force on the charges, here free electrons (and not a variation of Faraday flux): this Lorentz force F creates a field E moving the loads, as well as a voltage.

  It is known that machines have already been proposed using the same physical principle. The best known is the Gram machine which involves a rotor consisting of a ferromagnetic ring rotatably mounted about a coaxial axis of rotation. This ring carries a coil which extends over its entire circumference and is disposed in the magnetic field of a U-shaped permanent magnet.

  The connection of the winding to the external circuit (as the case may be, a generator or a circuit of use) is effected by means of two brushes coming into contact with the winding at two diametrically opposite points. This contact can be made on adjacent turns as the rotation of the rotor (sliding contact). As a result, between the two brushes, the current flows in two diametrically opposite parallel circuits formed by the two half-coils located on either side of the axis connecting the two brushes.

  In dynamo operation, this rotor is rotated by a motor member: the variation of: flux in the iron and therefore in the turns, generated by the rotational drive of the rotor, largely explains the electromotive force obtained.

  In motor operation, an electric current is applied to the winding. As a result, the conductors external to the ring, placed in a magnetic field, undergo Laplace forces whereas the conductors internal to the ring do not see the field and therefore do not act in the opposite direction. The power supply of the electric winding is effected by means of sliding contacts so that a continuous rotational movement of the rotor is obtained.

  Nevertheless, this type of machine proves to be very inefficient, in particular because of more or less inverse physical phenomena which come to hinder its good functioning. In addition, it involves sliding contacts (brushes) on a rotating collector, which in itself constitutes a significant drawback.

  The object of the invention is therefore more particularly to eliminate these disadvantages.

  It proposes, for this purpose, a machine comprising two parts subject to relative displacements with respect to each other, one of said parts including a magnetized structure comprising two parallel elements of opposite polarity, the other element comprising at least one winding mounted on a support made of a ferromagnetic material, which carries out a closed circuit and is arranged so as to achieve with the two elements of the magnetic structure at least two air gaps in at least one of which turns turns of the winding , the axis of the conductors of the winding located in this air gap being substantially parallel to the elements of the magnetized structure and perpendicular to the axis of relative displacement of the two moving parts, the two terminals of the winding being connected with a source of electric current, in the case of a motor-type operation, and the two parts being coupled to an actuator in the case of a dynamo type operation.

  Thanks to these provisions, instead of separating the current into two branches as in the gram machine, the current flows in the same circuit so that the support of the winding is magnetized without pole NS determined.

  In the case of a motor-type operation, there is therefore no torque between the magnetic field of the magnet and the coils. A relative displacement of the two structures appears because: the conductors of the two windings undergo Laplace forces in the same direction.

  An important advantage of the previously described structure is that the magnetic circuits of the two structures can be made of solid iron because there is no significant flux variation and therefore no eddy current. Nevertheless, the machine could also work with insulated laminated sheets to allow a non-homogeneous flow without excessive heating.

  Of course, the machine described above may be of rotary type or linear displacement type: In the case where it is of rotary type, the two parts will be rotatably mounted relative to each other. In this case, the support in ferromagnetic material on which the drive torque bears may have a shape of revolution coaxial with the axis of rotation of the two elements. In the case where the machine is of linear type, one of the two parts may be fixed and include a slide in which can slide the other part along a linear path.

  Embodiments of the invention will be described hereinafter, by way of non-limiting examples, with reference to the accompanying drawings, in which: FIG. 1 is a schematic representation illustrating the principle of a linear machine (motor or dynamo );

  Figures 2 and 3 are two alternative embodiments of the machine 20 using flux deflection shielding, Figure 3 providing a constant gap solution;

  Figures 4 and 5 are representations of two other variants in which the movable frame is rotated 90 relative to the previous solutions;

  Figure 6 is a view along AA of Figure 5 showing the fixed coils;

  FIG. 7 shows a machine comprising a U-shaped frame in which a permanent magnet carried by the fixed structure engages; FIG. 8 schematically represents an "extended" form of the machine illustrated in FIG. 7.

  Figure 9 is a schematic representation of a machine asymmetrical structure;

  Figures 10 and 11 are schematic axial sections (Figure 10) and radial (Figure 11) of a rotating machine; Figure 12 is a schematic representation of an alternative embodiment of the machine shown in Figure 11;

  Figure 13 is a schematic axial section of a rotating machine in the form of a wheel rotatably mounted about a fixed axis;

  Figure 14 is a partial radial section of the machine illustrated in Figure 13.

  In the example illustrated in FIG. 1, the machine is of linear type. It comprises a fixed part including a magnetized structure 1 of U-shaped section comprising a permanent magnet 2 of rectangular shape (at least a portion of the core of the U) whose two lateral faces are of opposite polarities (NS) and two parallel elements 3, 4 of parallelepipedal shape (wings of the U), which extend perpendicular to the main faces of the magnet 2. These two elements 3, 4 which bear on the side faces of the magnet 2, in a region adjacent to their lower edges, are made of a ferromagnetic material.

  In the parallelepipedal space E1 delimited by the structure 1 is arranged a structure 5 movable in translation guided by guide means not shown along an axis X, X 'perpendicular to the plane of the magnet 2.

  This mobile structure 5 comprises a rectangular frame 6 made of a ferromagnetic material such as mild steel, solid or laminated. On the uprights 7, 8 of this frame 6 are wound two respective windings 9, 10 connected in series and secured to the uprights 7, 8, for example by gluing. The frame 6 is arranged so that the uprights 7, 8 extend parallel to the elements 3, 4 while the two crosspieces 11, 12 extend parallel to the permanent magnet 2. Advantageously, the windings 9, 10 are made on the uprights 7, 8 before assembly of said uprights 7, 8 on the crosspieces 11, 12.

  The frame 6 provides a loopback of the magnetic field generated by the magnet 2 by forming between the elements 3, 4 and the uprights 7, 8 two air gaps el, e2 in which are located respectively the turns 9, 10 covering the outer side faces. amounts 7, 8.

  Thanks to these arrangements, by connecting the two terminals of the circuit formed by the two windings 9, 10 to a source of electric current, it is exerted on the winding portions 9, 10 located in the air gaps el, e2 a force of Laplace + F causing a displacement of the mobile structure 5 along the axis XX '. Possibly it will be possible, to avoid saturation phenomena of the frame, to provide at least one gap in the magnetic circuit of the frame.

  It is furthermore found that in this example, the flow f which propagates in one of the cross-members of the frame (here the upper cross-member 11) opposes the flux F of the magnet 2. To eliminate this drawback, one adds, for example in the manner illustrated in FIG. 2, a flux path consisting of a shield 13, to avoid disturbing the flow of the coils 9, 10 in the frame 6. In this example, this shield 13 has a shape in C lying whose core 17 extends opposite the crosspiece 11 while the two wings 18, 19 slightly overlap the uprights 7, 8. This shield 13 is also useful to avoid mutual inducing disturbances in a machine in which the mobile structure 5 comprises several frames 6, 6 '.

  Moreover, in order to control the flow path and the forces generated, the gaps e1, e2 between the parallel elements 3, 4 and the frame 6 of the mobile structure 5 must be equal, both at the level of the covered part. by the shield 13 than the uncoated portion.

  Figure 3 shows a solution for solving this problem.

  In this example, the parts of the frame 20 not covered by the shielding 13 '(which carries the windings) have an excess thickness 21, 22 which corresponds substantially to the thickness of the flanges 23, 24 of the shield. With these provisions, the gap Z at the portion of the excess thickness 21, 22 of an amount 25 carrying the winding 26 is equal to the sum of the air gap Y between the portion of the upright 25 without extra thickness and the wing 24 of the shield 13 'which covers it and the air gap x between the wing 24 of the shield 13' and the magnetized element 26.

  The invention is not limited to the embodiment described above. Thus, FIGS. 4 and 5 show a solution in which the frame 28 is constituted by a tubular section of square (or rectangular) cross section perpendicular to the permanent magnet 29 of the magnetized structure and of which two opposite sidewalls 30, 31 extend parallel to the wings 32, 33 of this structure.

  The windings 34, 35 are then carried out on these two lateral walls 30, 31 so that the sections of wire which cover the outer faces of these walls 30, 31 are oriented perpendicularly to the permanent magnet 29.

  With this dispositiort, the Laplace force applied to these son sections exerted in a direction parallel to the wings 32, 33 and the permanent magnet 29 (ie perpendicular to the plane of Figures 4 and 5).

  The guide means of the moving assembly (frame 28 + windings 34, 35) are therefore oriented in this direction.

  The machine according to the invention may comprise a succession of frames 30, 30 ', 30 "equipped with windings, these frames being axially movable in a fixed structure formed by a U-section rail made with the aid of two lateral wings. 32, 33 in ferromagnetic material connected by a permanent magnet 29 (or a juxtaposition of permanent magnets) which constitutes (s) the core of the rail, in the manner previously described, of course, the invention is not limited to a particular arrangement of permanent magnets and ferromagnetic material structures associated with these permanent magnets.

  The frames are mounted on support structures 36, 36 ', 36 "connected to each other by a fixing bar 37 (FIG. 6).

  Eventually these frames can be joined to each other so as to constitute a massive structure.

  FIG. 5 shows an alternative embodiment of the solution of FIG. 4 in which the fixed structure comprises a profiled rail 38 of U-shaped section completely of ferromagnetic material. The inner face of the wings 39, 40 of this rail 38 is provided with a plurality of flat permanent magnets 41, 42, the polarity of the magnets 41 carried by one of the wings 39 of the fixed structure being the same as that of the magnets 42 carried by the other wing 40 (S / N - S / N). Moreover, by slightly transforming the previously described device, it is possible to obtain a double-acting operation as shown in FIG.

  Thus, in this example the mobile structure comprises two coaxial parallelepipedal wings 43, 44 of ferromagnetic material parallel to the two wings 45, 46 of the fixed structure. These two wings 43, 44 are connected at their upper part, by a transverse piece 47 of ferromagnetic material, the assembly formed by the wings 43, 44 and the crosspiece 47 constituting a U-shaped structure disposed in the fixed structure in the inverted position with respect to the latter. In addition, the core 48 of the fixed structure carries at least one central permanent magnet 49 polarized in the opposite direction of the magnets 50, 51 carried by the fixed structure (S / N - S / N - S / N).

  This permanent magnet 49 which is carried by a base 52 of a non-magnetic material fixed on the core 48 of the fixed structure engages in the space delimited by the moving part.

  The windings 53, 54 are made around the flanges 43, 44 so that the wire sections which cover the outer lateral faces and the inner faces of said flanges are oriented perpendicularly to the core 48 of the fixed structure.

  Consequently, during the circulation of an electric current in the windings 53, 54, the sections of wire which cover the outer faces of the wings 43, 44 are in the magnetic field which circulates in the air gaps between the permanent magnets 50, 51 and the wings 43, 44, while the wire sections which cover the inner faces of the wings 45, 46 are in the magnetic field which circulates in the air gaps between the central magnet 49 and the wings 45 , 46. The magnetic circuit relating to the central magnet 49 successively comprises the magnet 49, the flange 44, the transverse piece 47, the flange 43 and the magnet 49.

  The magnetic circuit relative to the permanent magnets 50, 51 carried by the fixed structure comprises, meanwhile, a first permanent magnet 51 carried by a wing 46, a first wing 44, the transverse piece 47, a second wing 43, a second magnet permanent 50 carried by the other wing and the U-shaped rail.

  FIG. 8 schematically represents an "unfolded" form of the machine illustrated in FIG. 7. In this case, the fixed structure has a flat shape in which the wings 45 ', 46' carrying the magnets are in the extension of the 'soul 48'. The movable structure also has a flat shape in which the amounts 43 ', 44' carrying the coils are in the extension of the cross members 47 '. The central magnet 49 is here divided into two parts 49 'and 49 "carried by a flat support of ferromagnetic material, the operation of this machine is identical to that of FIG.

  Optionally, the machine illustrated in Figure 7 can be simplified by removing the central magnet 49, one of the permanent magnets 50 carried by the rail and the coil 53 located on the side of the wing 45 of the rail without permanent magnet . An asymmetrical structure is thus obtained comprising a single permanent magnet 51 "carried by the element 46 of the fixed structure and a coil 54 wound around the wing 44 of the mobile structure.The wing 43 of the mobile structure constitutes with 1 "Element 45 of the structure fixes an air gap through which is looped the flow (Figure 9). As previously mentioned, the invention also relates to rotating machines based on the same principle as the linear machines previously described.

  Thus, in the example shown in FIGS. 10 and 11, such a rotating machine involves a rotatable structure pivotally mounted about a fixed axis S. This rotary structure consists of two circular, coaxial flanges F1, F2, provided with coaxial bearings P1, P2 in which the shaft 50 engages. 10 The two flanges F1, F2 are provided, at their periphery, with at least one magnetic circuit 55, 56 of U-shaped section whose flanges 57, 58 -59, 60 are respectively fixed on the flanges F1, F2. The inner face of the wings 57, 58-59, 60 of this magnetic circuit 55 carries permanent magnets 61, 62-63, 64 relatively evenly distributed throughout the circumference.

  Furthermore, the shaft S carries a fixed structure 65 which extends radially inside the volume defined by the two flanges F1, F2 and on which is fixed a plurality of cores 66, 67, arranged so as to be able to 20 engage in the volume defined between the permanent magnets 61, 62-63, 64 delimiting with them air gaps.

  These cores 66, 67 carry windings 68, 69 whose sections of the turns passing through the air gaps are oriented radially. The electrical connections between the coils 68, 69 and the outside are effected by means of conductors passing through the shaft S.

  Of course, instead of using a plurality of permanent magnets 61, 62, it is possible to use a coaxial central magnet traversed by the shaft S and flanges of ferromagnetic material. In this case, the annular magnetic circuit 2912565 - 12 - is no longer necessary, the cores then forming air gaps with the flanges to ensure looping of the flow.

  The embodiment illustrated in FIG. 12 differs from that shown in FIGS. 10 and 11 in that the annular magnetic circuit has a shape in L and not in U, the radial flange 71 of this circuit carrying permanent magnets. , while the axial wing 73 is directly attached to the flange 74. The radial flange 71 is fixed to a flange 75 of smaller diameter.

  Furthermore, the magnetic cores 76 each carry a winding 77 whose turns extend in axial planes and define two air gaps respectively between the outer axial face of the core 76 and the axial flange 73 and between the permanent magnet 72 and the radial face of the core 76 adjacent to the magnet 72. The axial face of the cores 76 has axial notches 77 in which the coils of the coils engage. This results in a masking of the conductors of the turns in the notches relative to the return flow of the permanent magnet 72. In the embodiment illustrated in FIGS. 13 and 14, which involves a structure similar to that of FIGS. and 11, the circular magnetic circuit 80 carried by the two flanges 81, 82 has a section of more complex shape having: on the one hand, a C shape having a circular axial portion 83 extended at its lateral edges by two radial faces 84, 85 terminated by two returns 86, 87 parallel to the axial portion 83, and - secondly, two coaxial annular elements 88, 89 which radially extend the two returns 86, 87 and on which the two flanges 81, 82 come to fix themselves. The inner face of the circular axial portion 83 comprises in its central region an annular protuberance 90 carrying at least one permanent magnet 91 (or a mosaic of permanent magnets). The core 92 made of material. ferromagnetic carried by the shaft 93 is then disposed in the space delimited by the permanent magnet 91 and the two coaxial annular elements 88, 89, so as to produce three gaps, two of which are radial (between the core 92 and the annular elements 88, 89, and the third is axial (between the core 92 and the permanent magnet 91).

  The core 92 carries a coil 94 whose turns extend in axial planes. Here also the face of the core 92 facing the permanent magnet 91 is provided with grooves 95 (or notches) in which the turns 96 of the winding 94 pass.

  This arrangement is particularly suitable for the integration of a motor in a wheel or roller, for example a bicycle wheel, pivotally mounted on a hub. Naturally, the invention is not limited to the previously described embodiments. Thus, for example, the permanent magnets may be replaced partially or entirely by electromagnets.

  Likewise, the structures illustrated in FIGS. 1 to 9 can be deployed in the image of the transformation of FIG. 7 in FIG. 8.

Claims (21)

claims   1. Electrical machine DC without current switch, characterized in that it comprises two parts subject to relative movements with respect to each other, one of said parts including a magnetized structure (1) having two parallel elements (3, 4) of opposite polarity, the other part (5) comprising at least one winding (9, 10) mounted on a support made of a ferromagnetic material, which carries out a closed circuit and is arranged so as to realize with the two elements of the magnetized structure (1) two air gaps in at least one of which turns turns of the winding (9, 10), the axis of the winding conductors (9, 10) located in this gap being substantially parallel to the elements of the magnetized structure (1) and perpendicular to the axis of relative displacement of the two moving parts, the two terminals of the winding (9, 10) being connected with a source of electric current, in the case of n operation of the motor type, and the two parts being coupled to an actuator in the case of dynamo type operation.   2. Machine according to claim 1, characterized in that the magnetic circuits of the two parts are made of solid iron or with the aid of insulated laminations.   3. Machine according to one of claims 1 and 2, characterized in that it is of linear displacement type and in that, in this case, one of the two parts is fixed and comprises a slide in which can slide the other part.   4. Machine according to claim 3, characterized in that the fixed part comprises a magnetized structure 1 of U-shaped section whose core is constituted by a permanent magnet and in that in the space delimited by this structure (1) is guided a structure 2912565 -mobile in translation comprising a rectangular frame of ferromagnetic material comprising two uprights (7, 8) on which are wound two respective windings connected in series, said frame (6) ensuring a loopback of the magnetic field generated by the magnet (2) forming between the wings (3, 4) and the uprights (7, 8) two air gaps (el, e2) in which the turns covering the outer faces of the uprights pass.   5. Machine according to claim 4, characterized in that it further comprises a flow path consisting of a shield (13) comprising a core (17) extending opposite a cross member of the frame and two wings ( 18, 19) for covering the uprights (7, 8).   6. Machine according to claim 5, characterized in that the movable structure comprises a plurality of frames (6, 6 ').   7. Machine according to claim 5, characterized in that11es parts of the frame not covered by the shield has an extra thickness which substantially corresponds to the thickness of the wings of the shield.   8. Machine according to claim 7, characterized in that the gap (Z) at the portion of the extra thickness (21, 22) of an amount (25) carrying the winding (26) is equal to the sum the air gap (Y) between the portion of the upright (25) with no thickness and the wing (24) of the shielding (13 ') which covers it and the gap (x) between the wing (24) of the shielding (21) and the magnetized element (26).   9. Machine according to claim 4, characterized in that the frame (28) is constituted by a tubular section of square section (or rectangular) oriented perpendicularly to the permanent magnet (29) of the magnetized structure and two side walls opposite (30, 31) extend parallel to the wings (32, 33) of this structure, and in that the windings (34, 35) are then carried out on these two side walls (30, 31) of in such a way that the wire sections which cover the outer faces of these walls (30, 31) are oriented perpendicularly to the permanent magnet (29).   10. Machine according to claim 9, characterized in that it comprises a succession of frames (30, 30 ', 30 ") equipped with windings these frames being axially movable in a fixed structure 10 formed by a section rail in ( U) made with two lateral wings (32, 33) of ferromagnetic material connected by one or more permanent magnets (29) which constitute the core of the rail.   11. Machine according to claim 10, characterized in that the said frames are mounted on support structures (36, 36 ', 36 ") connected to each other by a fixing bar (37).   12. Machine according to claim 4, characterized in that the fixed structure comprises a profiled rail (38) of U-shaped section 20 made entirely of ferromagnetic material and in that the inner face of the flanges (39, 40) of this rail (38) is provided with a plurality of permanent magnets (41, 42) the polarity of the magnets (41) carried by one of the wings (39) of the fixed structure being the same as that of the magnets (42) carried by the other wing. 25   13. Machine according to claim 4, characterized in that the movable structure comprises two coaxial parallelepipedal wings (43, 44) of ferromagnetic material parallel to the two wings (45, 46) of the fixed structure, these two wings being connected at the their upper part by a transverse piece (47) of ferromagnetic material the assembly formed by the wings (43, 44) and the crosspiece 2912565 - 17 - (47) constituting a structure (U) disposed in the fixed structure in position inverted relative to the latter and in that the core (48) of the fixed structure carries at least one central permanent magnet (49) polarized in the opposite direction of the magnets (50, 51) carried by the fixed structure. 5   14. Machine according to claim 13, characterized in that the aforesaid permanent magnet (45) is carried by a base (52) of non-magnetic material fixed on the core (48) of the structure fixed to engage in the space delimited by the moving part; windings (53, 54) being made around the flanges (43, 44), so that the wire sections which cover the outer lateral faces and the inner faces of said flanges are oriented perpendicular to the core (48) of the fixed structure. 15   15. Machine according to claim 14, characterized in that the central magnet (49), one of the permanent magnets (50) carried by the rail and the coil (53) located on the side of the wing (45) of the rail with no permanent magnet are removed. 20   16. Machine according to one of claims 1 and 2, characterized in that it is rotating, in that the said parts are rotatable relative to each other, and in that the support of ferromagnetic material on which carries the driving torque has a form of revolution coaxial with the axis of rotation of the two elements. 25   17. Machine according to claim 15, characterized in that it comprises a rotary structure pivotally mounted about a fixed axis, this rotary structure comprising two coaxial circular flanges (F1, F2) provided with coaxial bearings (P1, P2) in The shaft (S) engages in that the two flanges (F1, F2) are provided at their periphery with at least one magnetic circuit (55, 56), of U, whose wings (57, 58-59, 60) are respectively fixed on the flanges (F1, F2), the inner face of the flanges (57, 58-59, 60) of this magnetic circuit (55) carrying magnets permanent uniformly distributed over the entire circumference. 5   18. Machine according to claim 16, characterized in that the shaft (S) carries a fixed structure (65) which extends radially inside the volume defined by the two flanges (F1, F2) and on which is fixed a plurality of cores (66, 67), arranged to be able to engage in the volume defined between the permanent magnets (61, 62-63, 64) delimiting with them air gaps, said cores (66, 67) carrying windings (68, 69) whose sections of the turns passing through the air gaps are mounted radially. 15   19. Machine according to claim 16, characterized in that the magnetic circuit has a shape of (L) and not (U) and in that the magnetic cores (76) each carry a winding (77) whose turns s' extend in axial planes and define two air gaps respectively between the outer axial face of the core (76) and the axial flange (73) and between the permanent magnet (72) and the radial face of the core (76) adjacent to the magnet (72).   20. Machine according to claim 17, characterized in that the magnetic circuit has a section comprising: on the one hand, a C shape having a circular axial portion (83) extended at its lateral edges by two radial faces (84, 85) terminated by two returns (86, 87) parallel to the axial portion (83), and - on the other hand, two coaxial annular elements (88, 89) radially extending the two returns (86, 87). and on which the two flanges (81, 82) are fixed, in that the inner face of the circular axial portion (83) comprises in its central region an annular protuberance (90) carrying at least one magnet permanent (91), and in that the core (92) of ferromagnetic material carried by the shaft (93) is then disposed in the space delimited between the permanent magnet (91) and the two coaxial annular elements (88). , 89), so as to produce three gaps, two of which are radial. between the core (92) and the annular elements (88, 89), and the third is axial between the core (92) and the permanent magnet (91), the core (92) carrying a winding (94) whose turns extend in axial planes. 10   21. Machine according to claim 20, characterized in that the face of the core (92) opposite the permanent magnet (91) is provided with grooves (95) (or notches) in which pass the turns (96) of the winding 94). 15