METHOD FOR WINDING A MULTI-NOTCH PER-POLE AND PER-PHASE ROTATING ELECTRIC MACHINE STATOR

Abstract

The invention relates to a method for winding a multi-slot, multi-phase, multi-pole, multi-phase stator (10) comprising, in particular: - a winding step of at least a portion of at least one first turn (Sp1) of a continuous conductor (C1, C2, C3) following a basic slot pitch (P_b), - a step of applying a special slot pitch (P_r) different from the basic slot pitch (P_b), - then a winding step of at least a portion of at least one second turn (Sp2) of said continuous conductor (C1, C2, C3) following the basic slot pitch (P_b), - said at least one first turn (Sp1) and said at least one second turn (Sp2) of a given phase winding (PH1, PH2, PH3) being continuously connected to each other by said continuous conductor (C1, C2, C3). Figure 2

Description

Title of the invention: METHOD FOR WINDING A STATOR OF A ROTATING ELECTRIC MACHINE WITH MULTI-NOTCHES PER POLE AND PER PHASE

[0001] The present invention relates to a method for winding a multi-slot stator per pole and per phase for a rotating electrical machine, as well as to the corresponding wound stator. The invention finds a particularly advantageous application for a stator of a rotating electrical machine such as, for example, an alternator, a starter-alternator, a reversible machine, or an electric motor of a vehicle or drone.

[0002] Rotating electrical machines, as is known per se, comprise a stator and a rotor fixed to a shaft. The rotor may be fixed to a driving and / or driven shaft. The electrical machine comprises a housing that carries the stator. This housing is also configured to support the rotation of the rotor shaft, for example, by means of bearings.

[0003] The stator comprises a body made up of a stack of sheet metal and a phase winding received in radially open stator slots. The phases are generally three in number for a three-phase machine or six for a six-phase machine.

[0004] In alternator stators of this type, the most commonly used winding types are "wave" windings comprising a plurality of phase windings. Each phase winding consists of a spiral conductor, each turn of which forms undulations running through the slots in the body. Thus, in each turn, the conductor has axial strands located inside the stator slots and connecting strands located alternately on each side of the stator, linking the axial strands together. The conductor may be made of one or more electrically conductive wires. The set of connecting strands extending from one side of the stator forms a winding coil. Each phase winding has a phase input and output corresponding respectively to a first and second end of a phase winding.The phase inputs and outputs are intended to be connected together to perform a coupling (delta, star, or hybrid of delta-star type or other) of the different phases of the electrical machine.

[0005] A winding method is known in which all the phase windings are wound simultaneously and in parallel in the corresponding slots of the stator body to obtain a six-phase winding. As illustrated by the [Fig.l], in order to transform a six-phase winding into a three-phase multi-slot winding per pole and per phase, it is necessary to make J1-J3 junctions between phase windings to go from six phase windings PH1-PH6 to three phase windings.

[0006] Such a transformation of a six-phase winding into a three-phase winding with multiple slots per pole and per phase makes it possible to obtain a compromise between performance and cost between a three-phase and a six-phase winding. Indeed, the resulting winding is more economical than a six-phase winding due to the reduction in the number of electronic components, while being more efficient than a three-phase winding.

[0007] To make the connections between the windings, an interconnector INT is generally used to connect the phase inputs and outputs. However, such an interconnector entails an additional cost, extra assembly steps to connect the phase inputs and outputs to said interconnector, and an increase in the overall size of a stator winding due to the presence of the interconnector.

[0008] The invention aims to effectively remedy the aforementioned drawbacks by proposing a winding method for a multi-slot polyphase stator per pole and per phase, said stator having slots intended to receive conductors of a winding, said winding comprising a number N of phase windings, said method comprising at least the following steps to produce each phase winding:

[0009] - a first winding step of at least a portion of at least a first a turn of a continuous conductor of a phase winding following a basic slot pitch, so as to leave at least one slot free between two slots intended to be filled by two continuous conductors of two adjacent phase windings,

[0010] - a step of applying a special notch pitch different from the notch pitch of base, such that the continuous conductor of said phase winding is inserted inside a free slot adjacent to a slot in which said continuous conductor of said phase winding is also inserted,

[0011] - then a second winding step of at least a portion of at least one second turn of said continuous conductor following the basic notch pitch,

[0012] - said at least a first turn and said at least a second turn of said in phase bearings being continuously connected to each other by said continuous conductor.

[0013] The invention thus makes it possible, by ensuring a continuous connection between the turns of a phase winding, to offer an economical solution compared to a similar winding where the connection between the turns is obtained by means of an interconnector. The invention also makes it possible to obtain a compact stator by avoiding the integration of an additional component near a winding. The invention also presents The advantage is reduced aerodynamic and magnetic noise compared to a standard three-phase machine. The invention also makes it possible to attenuate certain harmonics of the rotating electrical machine.

[0014] A "free slot" is understood to mean a slot which does not contain a conductor at a given stage of the winding process, it being understood that once the winding process is completed all the slots contain conductors.

[0015] The term "continuously" means a connection made directly by the conductor itself. No additional system such as an interconnector or a weld is necessary to make the electrical connection between the turns.

[0016] According to one embodiment of the invention, at least a portion of at least a first turn of a continuous conductor is wound in a first winding direction, and at least a portion of at least a second turn of said continuous conductor is wound in a second winding direction opposite to the first winding direction. This makes it possible to obtain less bulky coils, particularly in a radial direction, by alternating the position of the connecting strands in the front or back coil between the turns.

[0017] According to one embodiment of the invention, to perform each phase winding:

[0018] - the first winding step involves winding an integer number M of turns of the continuous conductor to form a first coil, and

[0019] - the second winding step involves winding an integer M' of turns of said continuous conductor to form a second coil,

[0020] - the special notch pitch being applied between the first coil and the second phase winding coil,

[0021] - said first coil and said second coil of said phase winding being continuously connected to each other by said continuous conductor.

[0022] For example, M and M' are integers strictly greater than 1.

[0023] Alternatively, each winding step involves winding a single turn.

[0024] According to one embodiment of the invention, the phase windings are wound simultaneously or one after the other.

[0025] According to one embodiment of the invention, the method comprises several steps of applying a special notch pitch and several winding steps following the basic notch pitch, each application step being preceded by a winding step and followed by another winding step, the turns of said phase winding obtained by the winding steps being continuously connected to each other by said continuous conductor.

[0026] According to one embodiment of the invention, the basic notch pitch is equal to the number of notches per pole and per phase multiplied by the number of phases N.

[0027] According to one embodiment of the invention, the special notch pitch is equal to the pitch of basic notches less k or at the basic notch pitch plus k, k being an integer greater than or equal to 1.

[0028] According to one embodiment of the invention, the special notch pitch is identical for all application steps.

[0029] For example, the winding is a three-phase winding with two slots per pole and per phase.

[0030] For example, the winding is a three-phase winding with 3 slots per pole and per phase.

[0031] According to one embodiment of the invention, the special slot pitch is decreasing such that the first special slot pitch is equal to the basic slot pitch less k and the subsequent special slot pitches are respectively equal to the preceding special slot pitch less k, or the special slot pitch is progressive such that the first special slot pitch is equal to the basic slot pitch plus k and the subsequent special slot pitches are respectively equal to the preceding special slot pitch plus k, k being an integer greater than or equal to 1.

[0032] For example, for a 3-turn winding, a basic slot pitch is applied equal to the number of slots per pole and per phase multiplied by the number of phases, i.e., a basic slot pitch equal to 9 slots, special slot pitches used during the application steps are respectively equal to the number of slots per pole and per phase multiplied by the number of phases minus 1, i.e., 8 slots, then the number of slots per pole and per phase multiplied by the number of phases minus 2, i.e., 7 slots.

[0033] For example, the winding is a three-phase winding with 4 slots per pole and per phase.

[0034] For example, for a 4-turn winding, a basic slot pitch equal to the number of notches per pole and per phase multiplied by the number of phases, i.e. a basic notch pitch of 12 notches, special notch pitches used during the application steps are respectively the number of notches per pole and per phase multiplied by the number of phases minus 1, i.e. 11 notches, then the number of notches per pole and per phase multiplied by the number of phases minus 2, i.e. 10 notches, then the number of notches per pole and per phase multiplied by the number of phases minus 3, i.e. 9 notches.

[0035] According to one embodiment of the invention, at least one special notch pitch is equal to the basic notch pitch less k and at least one other special notch pitch is equal to the basic notch pitch plus k, k being an integer greater than or equal to 1.

[0036] For example, the winding is a three-phase winding with 1 slot plus 2 half-slots per pole and per phase.

[0037] For example, for a 4-turn winding, a basic slot pitch of two slots per pole and per phase multiplied by the number of phases is applied, i.e., a basic slot pitch of 6 slots. Special slot pitches used before a change of winding direction are equal to the number of slots per pole. and per phase multiplied by the number of phases minus 1, i.e. 5 notches, then the number of notches per pole and per phase multiplied by the number of phases plus 1, i.e. 7 notches, then the number of notches per pole and per phase multiplied by the number of phases plus 1, i.e. 7 notches.

[0038] For example, the winding is a three-phase winding with 4 half-slots per pole and per phase.

[0039] For example, for a 4-turn winding, a basic slot pitch of two slots per pole and per phase multiplied by the number of phases is applied, i.e., a basic slot pitch of 6 slots, special slot pitches used before a change of winding direction being respectively equal to the number of slots per pole and per phase multiplied by the number of phases plus 1, i.e., 7 slots, then the number of slots per pole and per phase multiplied by the number of phases minus 1, i.e., 5 slots, then the number of slots per pole and per phase multiplied by the number of phases plus 1, i.e., 7 slots.

[0040] According to one embodiment of the invention, k is equal to 1.

[0041] According to one embodiment of the invention, the number of winding steps is equal to number of turns in the winding.

[0042] According to one embodiment of the invention, a continuous conductor of a phase winding is formed by a single continuous wire or by a bundle of at least two continuous wires.

[0043] The invention also relates to a multi-slot polyphase stator per pole and per phase, said stator comprising a winding comprising N phase windings and being wound according to the winding method described above, and slots receiving conductors of the winding, said winding comprising for each phase winding:

[0044] - at least a portion of at least one first turn wound from a continuous conductor of a phase winding following a basic slot pitch,

[0045] - a special slot pitch different from the basic slot pitch, so that the the continuous conductor of said phase winding is housed inside a free slot adjacent to a slot in which said continuous conductor of said phase winding is also housed,

[0046] - at least a portion of at least one second turn of said continuous conductor wound according to the basic notch pitch,

[0047] - said at least a first turn and said at least a second turn of said in phase bearings being continuously connected to each other by said continuous conductor.

[0048] According to one embodiment of the invention, the winding has at least one slot receiving continuous conductors belonging to several phase windings or in that all the slots in the winding house only continuous conductors belonging to the same phase winding.

[0049] According to one embodiment of the invention, at least a portion of at least a first turn of a continuous conductor is wound in a first winding direction and at least a portion of at least a second turn of said continuous conductor is wound in a second winding direction opposite to the first winding direction.

[0050] The invention further relates to a rotating electrical machine comprising a stator as previously defined.

[0051] According to one embodiment of the invention, the rotating electrical machine forms an alternator or an alternator-starter or a reversible machine or an electric motor.

[0052] The invention will be better understood upon reading the following description and examining the accompanying figures. These figures are given only by way of illustration and in no way limit the invention.

[0053] [Fig-1] Fig.1 illustrates, for a stator shown in flat projection, a confi three-phase winding configuration with two consecutive slots per pole and per phase without the present invention, therefore requiring an interconnector to connect the conductors present in two consecutive slots;

[0054] [Fig.2] Fig.2 is a perspective view of an example of a stator wound according to the present invention;

[0055] [Fig.3a] [Fig.3b] [Fig.3c] [Fig.3d] [Fig.3e] [Fig.3f] [Fig.3g] [Fig.3h] Figures 3a to 3h illustrate, for a stator represented in flat projection, the different stages of making a three-phase winding with two consecutive slots per pole and per phase;

[0056] [Fig.4] Fig.4 illustrates, for a stator shown in flat projection, a confi three-phase winding configuration with three consecutive slots per pole and per phase;

[0057] [Fig.5] Fig.5 illustrates, for a stator shown in flat projection, a confi configuration of three-phase winding with four consecutive slots per pole and per phase;

[0058] [Fig.6] Fig.6 illustrates, for a stator shown in flat projection, a confi configuration of three-phase winding with one slot plus two half-slots per pole and per phase;

[0059] [Fig.7] Fig.7 illustrates, for a stator shown in flat projection, a confi configuration of three-phase winding with four half-slots per pole and per phase;

[0060] [Fig.8] Fig.8 is a perspective view of two coils forming a phase bearings made from a continuous conductor;

[0061] [Fig.9] Fig.9 is a top view of a phase winding coil constructed following a distributed wavy configuration.

[0062] In Figures 2 and following, identical, similar, or analogous elements retain the same reference from one figure to another.

[0063] Figure 2 is a perspective view of a wound stator 10 of an electrical machine A rotating machine primarily comprises a body 11 in which several phase windings PHI, PH2, PH3 are mounted, forming an electrical coil. Examples of such a rotating machine include an alternator, a starter-alternator, a reversible machine, or an electric traction motor. This machine is preferably intended for use in a vehicle such as a motor vehicle or a drone. It should be noted that a starter-alternator is a rotating electrical machine capable of operating reversibly, firstly, as an electrical generator in alternator mode, and secondly, as an electric motor, notably for starting the internal combustion engine of a motor vehicle.

[0064] The machine (not shown) comprises a housing on which a voltage converter, such as an inverter or a rectifier bridge, can be mounted. Inside this housing, it also comprises a shaft, a rotor fixed to the shaft, and a stator 10. In this example, the stator is arranged to surround the rotor. The rotor rotates about an X-axis.

[0065] The rotor comprises, for example, a body formed by a stack of sheet metal held together as a bundle by means of a suitable fastening system, such as rivets passing axially through the rotor. The rotor comprises poles formed, for example, by permanent magnets housed in cavities within the rotor's magnetic mass. Alternatively, in a so-called "salient" pole architecture, the poles are formed by coils wound around rotor arms. Also alternatively, the rotor may be a claw rotor comprising two pole wheels. Each pole wheel consists of a transversely oriented plate, a plurality of claws forming magnetic poles, and a cylindrical core. The rotor comprises a coil wound around the core.

[0066] The stator body has an annular cylindrical shape with axis X and consists of an axial stack of flat sheets. The body 11 has teeth 12 distributed angularly and regularly around an inner circumference of a yoke 13. These teeth 12 define, in pairs, notches 15. The yoke 13 corresponds to the solid annular portion of the body 11 that extends between the bottom of the notches 15 and the outer periphery of the body 11.

[0067] The slots 15 open axially on either side of the body 11. The slots 15 are also radially open in the inner face of the body 11. In the embodiments shown below, the stator 10 has 36 slots to facilitate understanding of the invention. Preferably, the stator 10 is without tooth roots to facilitate the insertion of the conductors during the winding step. Alternatively, the stator may include tooth roots to improve the electrotechnical performance of the machine. Insulators 16 are arranged in the slots 15 to provide electrical insulation between the winding conductors and the stator body 11.

[0068] To form the stator winding 10, a number N of phase windings corresponding to the number of phases of the electrical machine are installed in the slots 15 of the body 11. In this case, the "three-phase" stator 10 comprises three phase windings P1, PH2, PH3. The invention is, however, applicable to stators comprising a different number of phase windings.

[0069] Each phase winding PHI, PH2, PH3 is made up of a corresponding continuous conductor Cl, C2, C3 folded into a serpentine shape and wound inside the stator in the slots 15 to form a plurality of turns.

[0070] In each turn, a conductor Cl, C2, C3 thus has axial strands 18 located in a series of slots 15 associated with a given phase winding PHI, PH2, PH3, as well as connecting strands 19a, 19b located alternately on each axial side of the stator body 11 and connecting the axial strands 18. The set of connecting strands 19a, 19b extending from one side of the body forms a winding coil. The slots 15 in a series are separated from each other by a slot pitch defined in more detail below. Winding several concentric turns makes it possible to achieve the complete phase winding. One turn corresponds to the winding of a conductor Cl, C2, C3 on one turn of the stator 10.

[0071] It should be noted that each conductor Cl, C2, C3 may comprise a single continuous wire or a bundle of F continuous conducting wires, F being greater than or equal to 2. In this case, the wires have a round cross-section. Alternatively, in order to optimize the filling of the slots 15, the wires may have a rectangular, square, or flat cross-section. In some embodiments, the wires may have axial strands 18 having a different shape from the connecting strands 19a, 19b. For example, the axial strands 18 may have a rectangular, square, or flat cross-section to optimize the filling of the slots 15, while the connecting strands 19a, 19b have a round cross-section to facilitate the formation of the winding coils. In all cases, the conductors Cl, C2, C3 are preferably made of a metallic material coated with enamel.The metallic material is preferably copper, but could alternatively be aluminium or any other material suitable for the application.

[0072] The winding method for a 10-phase polyphase stator with multiple slots per pole and per phase comprises at least the following steps to produce each phase winding PHI, PH2, PH3:

[0073] - a winding step of at least a portion of at least one first turn Spl of a continuous conductor Cl, C2, C3 following a basic slot pitch P_b, while providing at the beginning of the first turn free slots between two slots 15 intended to be filled by two continuous conductors Cl, C2, C3 of two adjacent phase windings PHI, PH2, PH3,

[0074] - a step of applying a different special notch pitch P_r, and in particular here less than the basic notch pitch P_b to finalize at least one first turn, so that the continuous conductor Cl, C2, C3 of a given phase winding PHI, PH2, PH3 is inserted inside a free notch 15 adjacent to a notch 15 in which said continuous conductor Cl, C2, C3 of said phase winding PHI, PH2, PH3 is also inserted,

[0075] - then a winding step of at least a portion of at least a second turn Sp2 of said continuous conductor Cl, C2, C3 according to the basic slot pitch P_b,

[0076] - said at least one first turn Spl and said at least one second turn Sp2 of a given phase winding PHI, PH2, PH3 being continuously connected to each other by said continuous conductor Cl, C2, C3.

[0077] Of course, as explained in more detail below, more than two turns Spl, Sp2 can be made to obtain the desired number of layers of conductors Cl, C2, C3 inside a notch 15.

[0078] The following example, with reference to Figures 3a to 3h, describes the steps for constructing a three-phase (N=3) wound stator 10 with two slots per pole and per phase. The three-phase stator 10 comprises three phase windings PHI, PH2, PH3. Each phase winding PHI, PH2, PH3 consists of a corresponding conductor Cl, C2, C3. In this case, conductors Cl, C2, C3 may each consist of a single continuous wire or a bundle of at least two continuous wires. In the example shown, the stator body 11 has 36 slots and 3 pole pairs.

[0079] More specifically, as illustrated in [Fig. 3a], the conductors Cl, C2, C3 are inserted into three separate slots 15. In this case, the conductors Cl, C2, C3 are inserted simultaneously into the slots 15. Alternatively, the conductors Cl, C2, C3 can be inserted one after the other. The portion of a conductor Cl, C2, C3 located inside a slot corresponds to an axial strand 18. The ends of the conductors Cl, C2, C3 that protrude from the body 11 and are located at the points A, B, C correspond to the phase inputs E1, E2, E3 of the phase windings PHI, PH2, PH3.

[0080] Two slots 15, each containing an adjacent phase winding, are separated by a free slot to allow the subsequent insertion of conductors Cl, C2, C3 during the second turn Sp2. In other words, conductors Cl, C2, C3 are inserted into every other slot. In the example shown, conductors Cl, C2, C3 are inserted into slots numbered 14, 16, and 18, respectively.

[0081] The conductors Cl, C2, C3 are then bent to form bonding strands 19a here of substantially triangular shape, which extend axially from the same side of the Body 11. Axial strands 18 of conductors C1, C2, C3 are then each inserted into a slot following a basic slot pitch P_b separating two adjacent slots of a series of slots 15 associated with a turn of a phase winding P1, PH2, PH3. The basic slot pitch P_b is equal to 2N, i.e., here P_b = 6 (N being the number of phase windings and the number 2 corresponding to the number of slots per pole and per phase). The conductors C1, C2, C3 are then bent to form connecting strands 19b which extend axially on one side opposite to that of the connecting strands 19a. Thus, the connecting strands 19a, 19b are located outside the body 11 alternately on one side or the other of the body 11. The set of connecting strands 19a, 19b protruding from the same side of the body 11 forms a winding bun.

[0082] We continue to wind the phase windings PHI, PH2, PH3 in a first winding direction Kl, in particular in a first circumferential direction, and in the basic notch pitch P_b up to the marks D, E, F located before the end of the first turn Spl.

[0083] As illustrated by [Fig. 3b], at the connecting strands 19a, 19b of the reference points D, E, F, i.e., just before the end of the first turn Spl, a special slot pitch P_r of 2N-1=5 is applied so as to insert the conductors Cl, C2, C3 of the phase windings PHI, PH2, PH3 into the slots 15 left free at the beginning of the first turn Spl. In the example shown, the conductors Cl, C2, C3 are inserted into the odd-numbered slots numbered 13, 15, and 17. The winding direction is then reversed to a circumferentially opposite direction K1 to create a second turn Sp2, using the basic slot pitch P_b. The first winding direction Kl could, for example, be clockwise and the second winding direction K2 could be counterclockwise or vice versa.

[0084] As illustrated by [Fig.3c], the second turn Sp2 is made following the basic notch pitch P_b up to the marks G, H, I. To simplify [Fig.3c], the first turn is not shown.

[0085] As illustrated in [Fig. 3d], at the connecting strands 19a, 19b of the reference points G, H, I, the special slot pitch P_r of 2N-1=5 is applied so as to insert the conductors C1, C2, C3 of the phase windings PHI, PH2, PH3 inside the even-numbered slots. This leads back to the series of even-numbered slots 14, 16, 18. The winding direction is then reversed again along the K1 direction to form a third turn Sp3, using the basic slot pitch P_b of 2N=6.

[0086] As illustrated by [Fig.3e], the third turn Sp3 is wound up to the marks J, K, L following the basic notch pitch P_b. To simplify [Fig.3e], the preceding turns are not shown.

[0087] As illustrated by [Fig.3f], at the level of the connecting strands 19a, 19b of the marks J, K, L, the special notch pitch P_r equal to 2N-1=5 is applied so as to insert the conductors Cl, C2, C3 of the phase windings PHI, PH2, PH3 inside the odd notches 13, 15, 17. The winding direction is changed again according to the K2 direction.

[0088] As illustrated by [Fig. 3g], a fourth turn Sp4 is then formed up to the marks M, N, O where the winding is stopped. The ends of the conductors Cl, C2, C3 located at the marks M, N, O correspond to the phase outputs SI, S2, S3 of the phase windings PHI, PH2, PH3.

[0089] Figure 3h illustrates the winding obtained at the end of the process, in which each conductor Cl, C2, C3 has been represented with a different type of line. This winding is of the distributed, interlocking corrugated type. It can be seen that each phase winding PHI, PH2, PH3 associated with a corresponding conductor Cl, C2, C3 passes through two consecutive slots 15. This results in a winding with two slots per pole and per phase without any junctions between the turns, since a single continuous conductor Cl, C2, C3 has been used to form each phase winding PHI, PH2, PH3.

[0090] It should be noted that in this type of winding, two consecutive turns Spi, Spi+1 are separated by a change of winding direction Kl, K2. The number of changes of direction is therefore equal to the total number of turns in the winding minus one. Thus, in the previous example, making 4 turns involved 3 changes of winding direction Kl, K2.

[0091] In this example, the phase inputs E1-E3 and phase outputs S1-S3 of the winding are grouped in the same area. This simplifies their connection to the voltage converter. At least one phase end of each phase winding is electrically connected to the voltage converter to allow an electric current to flow through the stator winding 10. This makes it easy to connect the phase windings PHI, PH2, PH3 in delta, star, or a hybrid delta-star connection, or other configurations.

[0092] Various embodiments of the multi-slot winding per pole and per phase are possible. For example, [Fig. 4] illustrates the embodiment of a three-phase winding with 3 turns and 3 slots per pole and per phase. According to this embodiment, a basic slot pitch P_b is applied, equal to the number of slots per pole and per phase multiplied by the number of phases, i.e., a basic slot pitch P_b of 9 slots. The special slot pitches P_r used before a change of winding direction K1, K2 are respectively equal to the number of slots per pole and per phase multiplied by the number of phases minus 1, i.e., 8 slots, and the number of slots per pole and per phase multiplied by the number of phases minus 2, i.e., 7 slots.

[0093] Figure 5 illustrates the realization of a three-phase winding with 4 turns and 4 slots per pole and per phase. According to this realization, a basic slot pitch P_b is applied, equal to the number of slots per pole and per phase multiplied by the number of phases, i.e., a basic slot pitch P_b of 12 slots. The special slot pitches P_r used before a change of winding direction K1, K2 are respectively equal to the number of slots per pole and per phase multiplied by the number of phases minus 1, i.e., 11 slots; then the number of slots per pole and per phase multiplied by the number of phases minus 2, i.e., 10 slots; and finally the number of slots per pole and per phase multiplied by the number of phases minus 3, i.e., 9 slots.

[0094] Figure 6 illustrates the realization of a three-phase, four-turn winding with one slot plus two half-slots per pole and per phase. A half-slot is defined as a slot occupied by two conductors C1, C2, C3 associated with two different phase windings P1, PH2, PH3. According to this embodiment, a basic slot pitch P_b is applied, equal to two slots per pole and per phase multiplied by the number of phases, resulting in a basic slot pitch P_b of six slots. The special slot pitches P_r used before a change of winding direction Kl, K2 are respectively equal to the number of slots per pole and per phase multiplied by the number of phases minus 1, i.e. 5 slots, then the number of slots per pole and per phase multiplied by the number of phases plus 1, i.e. 7 slots, then the number of slots per pole and per phase multiplied by the number of phases plus 1, i.e. 7 slots.Such a winding configuration allows the electromotive force of the electric machine to be smoothed.

[0095] Figure 7 illustrates the realization of a three-phase, four-turn winding with four half-slots per pole and per phase. According to this realization, a basic slot pitch P_b is applied, equal to two slots per pole and per phase multiplied by the number of phases, i.e., a basic slot pitch P_b equal to six slots. The special slot pitches P_r used before a change of winding direction K1, K2 are respectively equal to the number of slots per pole and per phase multiplied by the number of phases plus one, i.e., seven slots; then the number of slots per pole and per phase multiplied by the number of phases minus one, i.e., five slots; and finally, the number of slots per pole and per phase multiplied by the number of phases plus one, i.e., seven slots.

[0096] Alternatively, it is possible to achieve the winding with several slots per pole and per phase by winding several turns of wire before applying a special slot pitch. In the example of a winding with 2 slots per pole and per phase, said winding can be achieved by forming a first coil on a support, then offsetting it by one slot pitch to apply the special slot pitch P_r, and finally winding a second coil. The two coils are connected by wire continuity and are inserted into the stator pack. In this In this case, the process includes a step of winding an integer number M of turns Spl-SpM of a continuous conductor Cl, C2, C3 in the first winding direction Kl to form a first coil 21.1. Then, the process includes a step of winding an integer number M' of turns Spl-SpM' in the second winding direction K2 to form a second coil 21.2. The number of turns M, M' of each coil 21.1, 21.2 may be equal or different. Each coil 21.1, 21.2 may have a number of turns, for example, between 2 and 10. The coils 21.1, 21.2 may be obtained by winding a continuous conductor Cl, C2 in the same winding direction Kl, K2 or in different directions. The first coil 21.1 and the second coil 21.2 form the phase winding PHI. This process is repeated for the other phases of the winding.

[0097] The special notch pitch P_r is applied between the first coil 21.1 and the second coil 21.2 of the phase winding PHI, PH2, PH3. The first coil 21.1 and the second coil 21.2 of a given phase winding PHI, PH2, PH3 are continuously connected to each other by the continuous conductor Cl, C2, C3.

[0098] According to a particular embodiment, as illustrated by [Fig.8], each coil 21.1, 21.2 can in a first assembly step be formed flat, that is to say that the turns Spl-SpM; Spl-SpM' each extend in a plane substantially perpendicular to the axis A.

[0099] Each coil 21.1, 21.2 comprises a superposition of identical turns in the shape of regular stars with axis A, axis A being coaxial with the X-axis of the machine. The turns Spl-SpM; Spl-SpM' of each coil 21.1, 21.2 are formed according to the basic slot pitch P_b. The two coils 21.1, 21.2 are continuously connected to each other since the same continuous conductor Cl, C2, C3 is used to make both coils. The portion 22 thus corresponds to the portion of the continuous conductor Cl, C2, C3 providing the continuous electrical connection between the two coils 21.1, 21.2.

[0100] In a second assembly step, the phase winding PHI, PH2, PH3 is mounted on the stator body 11 by deformation. More precisely, the winding is positioned in the slots 15 of the body 11 by progressively twisting the axial strands 18 axially from front to back and by simultaneously tilting all the axial strands 18 from a direction perpendicular to the axis A to a direction parallel to said axis A. This deformation is obtained, for example, by sliding an insertion block not shown here.

[0101] The insertion is carried out so that the two coils 21.1, 21.2 are inserted into different slots 15. The connecting portion 22 allows the offset between the slots of the two coils 21.1, 21.2 to be obtained by applying the special slot pitch P_r. It will thus be possible to easily obtain a wound stator 10 to two notches per pole and per phase by an offset obtained by applying a special notch pitch P_r between the two coils 21.1, 21.2.

[0102] These assembly steps are then repeated so as to insert the other phase windings to form the electrical winding.

[0103] The phase windings can thus be mounted successively one after the other in the stator body 11. However, the invention is also applicable to mounting methods in which at least two windings, or even all the windings, are mounted simultaneously in the stator body 11.

[0104] A coil 21.1, 21.2 can be made in simple wave as shown in [Fig.8], i.e. the connecting strands are arranged alternately on either side of the stator body 11. Alternatively, it is possible to make a winding of the "distributed wave" type in which the turns of the same coil 21.1, 21.2 are waved in opposition, as illustrated by [Fig.9]. Thus, the upper connecting strands 19a and the lower connecting strands 19b of the same coil 21.1, 21.2 are angularly offset around the axis A. The angular offset is carried out in such a way that each connecting strand 19a, 19b comes to be placed in the free space between two successive connecting strands 19a, 19b of a previous undulation of a conductor Cl, C2, C3.

[0105] The winding steps described above can be carried out in situ directly on the stator body 11. Alternatively, the winding steps can be carried out on a spindle and then the winding obtained on the spindle is transferred inside the slots 15 of the stator body 11.

[0106] The present invention finds advantageous applications in the field of stators for alternators or reversible machines, but it could also be applied to any type of rotating machine.

[0107] Of course, the preceding description has been given by way of example only and does not limit the scope of the present invention, which would remain within the scope of the invention even if the various elements were replaced by any other equivalents. For example, the invention is an application to an electrical winding comprising more than three phases, such as five, six, or seven phases. Thus, increasing or decreasing the number of phases of the stator 10 would not depart from the scope of the invention.

Claims

Demands

1. A method for winding a multi-slot, multi-phase, multi-slot stator (10) per pole and per phase, said stator (10) having slots (15) for receiving conductors (C1, C2, C3) of a winding, said winding comprising a number N of phase windings (P1, PH2, PH3), characterized in that said method comprises at least the following steps for making each phase winding: - a first winding step of at least a portion of at least one first turn (Spl) of a DC conductor (C1, C2, C3) of a phase winding (P1, PH2, PH3) following a basic slot pitch (P_b), so as to leave at least one slot free between two slots (15) intended to be filled by two DC conductors (C1, C2, C3) of two phase windings (P1, PH2, PH3 ... PH3) adjacent, - a step of applying a special notch pitch (P_r) different from the basic notch pitch (P_b), so that the continuous conductor (Cl, C2,C3) of said phase winding (PHI, PH2, PH3) is inserted inside a free slot (15) adjacent to a slot (15) in which said continuous conductor (Cl, C2, C3) of said phase winding (PHI, PH2, PH3) is also inserted, - then a second winding step of at least a portion of at least a second turn (Sp2) of said continuous conductor (Cl, C2, C3) following the basic slot pitch (P_b), - said at least a first turn (Spl) and said at least a second turn (Sp2) of said phase winding (PHI, PH2, PH3) being continuously connected to each other by said continuous conductor (Cl, C2, C3).

2. Method according to claim 1, characterized in that at least a portion of at least a first turn (Spl) of a continuous conductor (Cl, C2, C3) is wound in a first winding direction (Kl) and at least a portion of at least a second turn (Sp2) of said continuous conductor (Cl, C2, C3) is wound in a second winding direction (K2) opposite to the first winding direction (Kl).

3. Method according to claim 1 or 2, characterized in that to carry out each phase winding (PHI, PH2, PH3): - the first winding step comprises winding an integer number M of turns of the direct conductor (Cl, C2, C3) to form a first coil (21.1), - the second winding stage involves winding an integer number M' of turns of said continuous conductor (Cl, C2, C3) to form a second coil (21.2), - the special notch pitch (P_r) being applied between the first coil (21.1) and the second coil (21.2) of the phase winding (PHI, PH2, PH3), - said first coil (21.1) and said second coil (21.2) of said phase winding (PHI, PH2, PH3) being continuously connected to each other by said continuous conductor (Cl, C2, C3).

4. A method according to any one of the preceding claims, characterized in that the phase windings (PHI, PH2, PH3) are wound simultaneously or one after the other.

5. A method according to any one of the preceding claims, characterized in that it comprises several steps of applying a special notch pitch (P_r) and several winding steps following the basic notch pitch (P_b), each application step being preceded by a winding step and followed by another winding step, the turns of said phase winding (PHI, PH2, PH3) obtained by the winding steps being continuously connected to each other by said continuous conductor (Cl, C2, C3).

6. A method according to the preceding claim, characterized in that the special notch pitch (P_r) is equal to the basic notch pitch (P_b) less k or to the basic notch pitch (P_b) plus k, k being an integer greater than or equal to 1.

7. A method of any one of claims 5 or 6, characterized in that the special notch pitch (P_r) is identical for all application steps.

8. The method according to claim 5, characterized in that: - the special notch pitch (P_r) is decreasing such that the first special notch pitch is equal to the basic notch pitch (P_b) less k and the subsequent special notch pitches are respectively equal to the previous special notch pitch less k, or - the special notch pitch (P_r) is progressive such that the first special notch pitch is equal to the basic notch pitch (P_b) plus k and the subsequent special notch pitches are respectively equal to the previous special notch pitch plus k, - k being an integer greater than or equal to 1.

9. A method according to claim 5, characterized in that at least one step special notch pitch (P_r) is equal to basic notch pitch (P_b) minus k and in that at least one other special notch pitch (P_r) is equal to basic notch pitch (P_b) plus k, k being an integer greater than or equal to 1.

10. A method according to any one of claims 6 to 9, characterized in that k is equal to 1.

11. A method according to any one of the preceding claims, characterized in that the number of winding steps is equal to the number of turns in the winding.

12. A method according to any one of claims 1 to 11, characterized in that a continuous conductor (Cl, C2, C3) of a phase winding (PHI, PH2, PH3) is formed by a single continuous wire or by a bundle of at least two continuous wires.

13. A multi-slot, multi-phase stator (10) per pole and per phase, said stator (10) comprising a winding comprising a number N of phase windings (PHI, PH2, PH3) and being wound according to the winding method according to any one of the preceding claims, and slots (15) receiving conductors (Cl, C2, C3) of the winding, said winding comprising for each phase winding: - at least a portion of at least one first turn (Spl) wound from a continuous conductor (Cl, C2, C3) of a phase winding (PHI, PH2, PH3) following a basic slot pitch (P_b), - a special slot pitch (P_r) different from the basic slot pitch (P_b), such that the continuous conductor (Cl, C2, C3) of said phase winding (PHI, PH2, PH3) is housed inside a free notch (15) adjacent to a notch (15) in which is also housed said continuous conductor (Cl, C2, C3) of said phase winding (PHI, PH2, PH3),- at least a portion of at least a second turn (Sp2) of said continuous conductor (Cl, C2, C3) wound according to the basic slot pitch (P_b), - said at least a first turn (Spl) and said at least a second turn (Sp2) of said phase winding (PHI, PH2, PH3) being continuously connected to each other by said continuous conductor (Cl, C2, C3).

14. Stator (10) according to the preceding claim, characterized in that the winding has at least one slot (15) receiving continuous conductors (C1, C2, C3) belonging to several phase windings (PHI, PH2, PH3) or in that all the slots (15) of the winding house only continuous conductors (Cl, C2, C3) belonging to the same phase winding (PHI, PH2, PH3).

15. Rotating electrical machine comprising a stator as defined according to claim 13 or 14.

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