ELECTRIC MACHINE ROTOR, PARTICULARLY FOR MOTOR VEHICLES

Abstract

The invention relates to an electric machine rotor, comprising at least one armature having a plurality of poles (10), a wire of a winding (18) wound on each pole (10) and distributed over a span (20) of length (L) of said pole (10) in layers (CN) of turns superimposed one on top of the other, each of these superimposed layers (CN) being of a level (N) determined moving away from said pole (10) and having a number (n) of ranks (Rn) of turns determined along said pole (10), wherein: at least the first level layer (C1) extends along the entire length of the pole (10), from a determined layer (C3), the superimposed layers (CN) of subsequent increasing levels have a decreasing number (n) of ranks (Rn). Figure 4 for the abstract.

Description

Title of the invention: ELECTRIC MACHINE ROTOR, PARTICULARLY FOR MOTOR VEHICLES Technical field of the invention

[0001] The invention relates to an electric machine rotor and an electric machine comprising such a rotor. It will find applications, in particular, in motor vehicles. Technical background

[0002] An electric machine rotor consists of an armature and a rotor shaft, which is integral with said armature and which enables the mechanical coupling of the electric machine.

[0003] The armature functionally delimits a central hub, which is coupled to the rotor shaft, and poles extending from this hub, and which are distributed substantially regularly around this hub. These poles receive a winding, consisting of one or more windings made on these poles.

[0004] The winding is wound around the rotor poles according to a predefined pattern.

[0005] Conventionally, this winding is carried out over a span of determined length on each pole, using a determined number of layers of turns, each having the same determined number of rows corresponding to a total length of the span between a foot and a head of the pole. The winding therefore has a substantially regular overall shape around each pole.

[0006] In a known manner, the adjacent poles are separated by a space that is configured to allow the winding process and the installation of a wedge. This space extends at least radially at the right-hand side of a determined clearance between the feet of adjacent poles.

[0007] Consequently, given the configuration mentioned above, the diameter of the winding of the coil around each pole is necessarily limited by the imperative that it must not interfere with this space in the vicinity of the feet of the poles.

[0008] It follows that, moving away from the feet of the poles and towards the heads of the poles, a considerable part of the volume between poles is not occupied by the winding, whereas a greater number of turns would increase the magnetic efficiency of the winding.

[0009] Furthermore, increasing the width of the rotor poles improves the compactness of the motor. However, such an increase necessarily entails a reduction in the space between the poles and the aforementioned clearance.

[0010] There is therefore a real need for a winding configuration of the coil which allows a maximum number of turns to be wound around each pole, without interfering with the space and the determined clearance mentioned above. Summary of the invention

[0011] The invention satisfies this need by proposing a winding configuration having a truncated conical shape near the feet of the poles.

[0012] To this end, the invention proposes an electric machine rotor, comprising at least one winding armature having a central hub with axis A around which is arranged a plurality of poles, a winding wire wound on each pole and distributed over a determined length between a foot and a head of said pole at least in layers of turns superimposed one on the other, said superimposed layers, each of said superimposed layers being at a determined level moving away from said pole and having a determined number of rows of turns along said pole,

[0013] in which: - at least the first-level layer extends along the entire length of the pole, - starting from a given layer, the superimposed layers of subsequent increasing levels have a decreasing number of ranks.

[0014] This winding configuration allows a maximum number of turns to be arranged around each pole without interfering with the space which is configured to allow the passage of a winding needle and / or the placement of a shim, which makes it possible to improve overall the efficiency of the magnetic circuit of the rotor, and consequently of the electric machine.

[0015] According to various additional features of the structural panel according to the invention, which may be taken together or separately and which constitute so many embodiments of the invention:

[0016] - the rows of turns extend contiguously from one end of the range turned towards the head of the pole,

[0017] - from said determined layer, from a layer superimposed on a layer superimposed on the next higher level, the number of ranks decreases by a constant ratio,

[0018] - from said determined layer, from a layer superimposed on a layer superimposed on the immediately higher level, the number of ranks decreases arithmetically by said constant common ratio,

[0019] - said reason is one,

[0020] - the rotor comprises a so-called terminal layer extending a final layer superimposed, said terminal layer comprising: • a first part extending from the top of the pole, continuing the last superimposed layer, resting on said last superimposed layer and having a number of ranks lower than said last superimposed layer, • a second part extending the first part, facing towards the base of the pole, and comprising at least two rows resting on at least two superimposed layers of levels lower than said last superimposed layer, - the second part of the terminal layer of the winding of one of the poles is connected to the first first-level layer of another of the poles or to the outside of the poles. - said other pole is a neighbouring pole, in particular an adjacent pole. - the rotor includes: • two superimposed layers of first and second levels extending along the entire length of the pole, • at least three superimposed higher-level layers with a number of ranks decreasing by a factor of one from the second-level layer, • the terminal layer, the second part of which comprises at least four rows resting on at least three of the superimposed layers of levels lower than the last superimposed layer,

[0021] - said wound poles define a specific space configured to allow the passage of a winding needle to the base of said poles,

[0022] - said space extends at least radially at the right of a determined gap between the feet of the poles,

[0023] - a shim is arranged between the windings of each pair of adjacent poles,

[0024] - the wedge is configured to be inserted axially between the poles,

[0025] - the wedge extends radially to the hub,

[0026] - the wedge has, near the base of the poles, a summit having a shape substantially complementary to a gap between the windings,

[0027] - the shape is an outgrowth wider than the determined set,

[0028] - the number of levels and the reason for rank decrease are configured for that each winding be at a distance from said space,

[0029] - each winding is of the orthocyclic type, each turn being arranged in staggered with at least two other turns in contact with said turn,

[0030] - the poles are regularly distributed angularly around the hub.

[0031] The invention also aims to protect an electrical machine, comprising a rotor of the type described above. Brief description of the figures

[0032] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent in the course of the detailed explanatory description which follows, of at least one embodiment of the invention given by way of purely illustrative and non-limiting example, with reference to the accompanying schematic drawings, among which:

[0033] The [Fig. 1] is a detailed cross-sectional view of an electrical machine armature;

[0034] Fig. 2 is a detailed cross-sectional view of a wound pole of a rotor of an electrical machine according to the invention;

[0035] The [Fig.3] is a detailed cross-sectional view of two wound poles close to the rotor of the electric machine of the [Fig.2];

[0036] Fig. 4 is a cross-sectional detail view of a wound half-pole of the rotor of the electric machine of Fig. 2. Detailed description of the invention

[0037] A cross-section of a rotor 12 of an electric machine with poles 10 is shown in [Fig.1]. In the remainder of this description, a rotor 12 of an electric machine with axis A according to the invention will only be shown partially in the vicinity of one or more of its poles 10, but it will be understood that the invention applies to the whole of the rotor 12 and therefore to all of its poles 10.

[0038] The rotor 12 comprises at least one winding armature 14 having a central hub 16 of axis A around which a plurality of poles 10 are arranged. The poles 10 are regularly distributed angularly around the hub 16. The armature 14 receives a winding 18, as shown in figures 2 to 4.

[0039] A wire of the winding 18 is wound on each pole 10 around a radial direction R. As illustrated in [Fig.3], this wire is distributed over a span 20 of length L determined between a foot 22 and a head 24 of said pole 10.

[0040] The winding wire 18 is, as illustrated in [Fig.4], arranged at least in layers CN of turns superimposed one on top of the other, called superimposed layers, the index N in the designation of each superimposed layer corresponding to a level N determined by moving away from the pole 10. Thus, in the example of [Fig.4], we distinguish by way of example the layers Ci, C2, C3, C4, C5 as they move away from the span 20 of the pole 10 and approach the outside of the pole 10.

[0041] The layers have a number of rows Rn of turns determined along the pole 10, between the foot and the head of the pole, that is to say at the span 20.

[0042] By way of example, the ranks Ri to Ri9 on layer Ci are shown in [Fig. 4], then the ranks R20 to R38 of layer C2, with rank R20 being adjacent to rank R9 of layer Cp

[0043] Layer C2 extends to rank R38 at the other end of layer C2, rank R38 being adjacent to rank R39 of layer C3.

[0044] The C3 layer extends to rank R56 at the other end of the C3 layer, this rank R56 being adjacent to rank R57 of the C4 layer.

[0045] Layer C4 extends to rank R7[ at the other end of layer C4> this rank R7i being adjacent to rank R72 of layer C5, which extends to rank R85.

[0046] The rows n follow one another in ascending order, including when changing layers of turns. It will also be understood that, while the number n of rows always increases, the progression of the winding during its winding changes direction when passing from one layer of turns to the next, since each layer is wound on the previous one, extending in the opposite direction.

[0047] In the case of a winding with radial axis R, as is the case here, the winding of the wire of the coil 18 around each pole 10 is generally carried out by means of a needle. As illustrated by the dashed lines in [Fig. 3], this needle (not shown), whose trace T can be seen, is inserted radially between the adjacent poles 10 and is moved around the poles 10, that is to say in front of, behind, and between the poles 10 in a space E which is configured to allow the passage of this winding needle. This space E extends at least radially at the right-hand side of a determined gap J between the feet 22 of the neighboring poles 10, this gap J representing the minimum distance between the poles 10 which is suitable for allowing the passage of the winding needle.

[0048] A conventional winding (not shown) is formed on the span 20 with a predetermined number of layers of turns, each having the same predetermined number of rows Rn corresponding to the total length L of the winding span 20. The winding of the wire therefore has, in a conventional winding, a generally regular tubular shape around each pole 10.

[0049] Consequently, given the configuration mentioned above, in the context of a conventional winding, the diameter of the winding of the wire of the winding 18 around each pole 10 is necessarily limited by the imperative that it must not interfere with this space E.

[0050] Furthermore, as illustrated in [Fig. 2], once the windings 18 have been formed, a protective spacer 17 is arranged between the windings of each pair of adjacent poles 10. This spacer 17 is configured to be inserted axially between the poles 10, parallel to the direction A.

[0051] Increasing the number of poles of a rotor improves the compactness of the motor. However, such an increase necessarily entails a reduction in the spacing E between the poles 10, and in the aforementioned backlash J. Consequently, increasing the number of poles 10 of a rotor limits the number of turns in the winding.

[0052] The invention overcomes this drawback by proposing a winding of the wire of the coil 18 having a non-tubular and partly frustoconical shape, allowing it to adapt to a reduced inter-pole spacing E in order to improve the magnetic efficiency of the coil. This winding also makes it possible to offer a radially longer spacer 17 extending to the hub 14.

[0053] To this end, the invention proposes a rotor 12 of the type described above, in which: - at least the first-level layer Ci extends along the entire length L of pole 10, - starting from a given layer, the superimposed layers of subsequent increasing levels N have a decreasing number n of ranks.

[0054] This configuration has been illustrated by way of example in [Fig. 4]. As has been seen, the first-level layer Ci extends along the entire length L of the pole 10 between the pole foot and the pole head and has 18 rows from Ri to Ri9. The second-level layer C2 also extends along the entire length L of the pole 10 and has 18 rows from R20 to R38. According to the invention, starting with the third-level layer C3, the superimposed layers of subsequent increasing levels N have a decreasing number n of rows.

[0055] According to the invention, the Rnde turns extend contiguously from an end 20a of the span 20 facing the head 24 of the pole 10. In other words, from the determined layer, here the third level C3 layer, the CN layers of turns have their turns grouped on the side of the end 20a of the span 20 facing the head 24 of the pole 10, while these layers are progressively sparse on the side of an end 20b of the span 20 facing the foot 22 of the pole 10, as the index N of these layers is increasing.

[0056] Preferably, from a CN layer superimposed on a CN+isuperimposed layer of the immediately higher level, starting from the determined layer, here the third-level C3 layer, the number of ranks n decreases by a constant common ratio. It will be understood here that from a CN layer superimposed on a CN+isuperimposed layer of the immediately higher level, the number of ranks decreases arithmetically by said constant common ratio.

[0057] Preferably, and without limiting the invention, said reason is one. Thus, from the determined layer, here the third-level C3 layer, each layer has one fewer row of turns than the previous layer.

[0058] Preferably, the poles do not consist solely of so-called superimposed layers. At the end of the winding of each pole, as illustrated in [Fig. 4], the rotor 12 has a so-called terminal layer CT extending from a final superimposed layer. In the example shown here, the terminal layer CT extends from the final superimposed layer C5.

[0059] This CT layer comprises a first part CTa extending from the head of pole 10, and continuing the last superimposed layer, here layer C5, and resting on said last superimposed layer C5. As one of the superimposed layers, this first part CTa of the terminal layer CT has fewer ranks than the last superimposed layer C5. Here, the CTa layer of the terminal layer CT has 13 ranks, from rank R86 to rank R98, while the last superimposed layer C5 has 14, from rank R72 to rank R85.

[0060] It should be noted that the terminal layer CT here has one less rank than the last superimposed layer C5, but this configuration is not limiting of the invention and it could thus have an even lower number of ranks compared to the last superimposed layer C5.

[0061] Extending this first part CTa, the layer CT comprises a second part CTb extending the first part CTa, which is turned towards the foot 22 of the pole 10. The second part CTb comprises at least two rows distributed and resting on at least two superimposed layers of levels lower than the last superimposed layer, here layer C5.

[0062] Here, the CT layer therefore comprises a second part Cn, extending the first part CTa. This second part CTb comprises four ranks R99, Ri00, Riou, and R102 resting on three superimposed layers C4, C3, and C2 of lower levels than the last superimposed layer C5. The distribution of the ranks of the second part CTb on the superimposed layers of lower levels depends on the available space, but in any case, it is desirable that the last rank, here rank R102, be as close as possible to the end 20b of the span 20, which is located near the foot 22 of the pole 10.

[0063] In other words, in the illustrated example, in said second part CTb, the rows of the terminal layer are at a different level from the rows of the first part CTa, and are not all at the same level with each other. Thus, in said second part CTb, the turns follow one another, approaching radially and axially the foot 22 of pole 10, with each turn and / or group of turns, the last turn resting, for example, on the superimposed second-level layer, adjacent to the last turn of the superimposed third-level layer.

[0064] Indeed, the second part CTb of the terminal layer CT of the winding of one pole is connected to the first layer Ci of the first level of another pole or to the outside of the poles. In the case of another pole 10, the other pole 10 is preferably a neighboring pole 10, and in particular an adjacent pole 10.

[0065] In the case where the wire passes from one pole 10 to another, as the first layer Ci of the first level of another pole has its first row close to the side of the foot 22 of the pole 10, it is desirable that the last row of the winding, here the row R102, also be close to the side of the foot 22 of the pole in order to minimize the wire lengths between the poles 10.

[0066] In the case where the wire comes out of the pole 10, it is also desirable that the last row of the winding also be close to the side of the foot 22 of the pole in order to allow the wire to exit as close as possible to the axis of the rotor, in order to allow its connection to a rotating collector (not shown) fitted onto the axis of the rotor.

[0067] Such a winding allows for optimal use of the number of layers and the number of rows per layer in order to maximize the number of turns and thus increase the efficiency of the rotor 12's magnetic circuit. It will be understood that the number N of levels CN and the decay ratio Rn are configured so that each winding is at a distance from the space E, this therefore depending on the number of poles. In particular, the arithmetic difference in decay may be greater than 1 if the geometric configurations so require.

[0068] Advantageously, as illustrated in [Fig. 2], with such a winding, the wedge 17 extends radially to the hub 14 and, near the base of the poles, has a vertex 19 with a shape 21 substantially complementary to a gap between the windings 18 of two adjacent poles 10. This shape 21 is a protrusion wider than the determined clearance J, which allows for optimal stabilization of the wedge 17 between the poles 10, since the wedge 17 is contained between the windings 18 and since it extends to the hub 14.

[0069] In other words, the wedge 17 has a first, substantially trapezoidal cross-section opposite the first part Ta of the terminal layer and, extending from said first cross-section, a second, substantially rectangular cross-section and / or flaring out towards the hub 16, opposite said second part Tb of the terminal layer. This second section has an added thickness in the form of an annular ring opposite a hollow between two of the turns.

[0070] In the preferred embodiment of the invention, each winding is of the orthocyclic type, that is to say that each turn is arranged in a staggered fashion with at least two other turns in contact with said turn, which ensures optimal holding of each turn between at least two other turns.

[0071] The invention is applicable to any rotor 12 of an electrical machine, and to any electrical machine comprising such a rotor.

Claims

Demands

1. An electric machine rotor (12) comprising at least one winding armature (14) having a central hub (16) with axis A around which are arranged a plurality of poles (10), a wire of a winding (18) wound on each pole (10) and distributed over a span (20) of determined length (L) between a foot (22) and a head (24) of said pole (10) at least in layers (CN) of turns superimposed one on the other, said superimposed layers (CN), each of said superimposed layers (CN) being of a level (N) determined moving away from said pole (10) and having a number (n) of rows (Rn) of turns determined along said pole (10), in which: - at least the first-level layer (Ci) extends along the entire length of the pole (10), - from a determined layer (C3), the layers (CN) superimposed of successive increasing levels have a decreasing number (n) of ranks (Rn).

2. Electric machine rotor (12) according to the preceding claim, wherein the rows (Rn) of turns extend contiguously from one end (20a) of the span (20) turned towards the head (24) of the pole (10).

3. Electric machine rotor (12) according to any one of the preceding claims, wherein, from the determined layer (C3), from a layer (CN) superimposed to a layer (CN+i) superimposed of level (N+1) immediately above, the number (n) of ranks is decreasing by a constant ratio.

4. Electric machine rotor (12) according to the preceding claim, wherein said reason is one.

5. Rotor (12) of an electric machine according to any one of the preceding claims, comprising a terminal layer (CT) extending from a last superimposed layer, said terminal layer (CT) comprising: - a first part (CTa) extending from the head 24 of the pole 10, extending the last superimposed layer (C5), resting on said last superimposed layer (C5) and having a number of ranks less than said last superimposed layer (C5), - a second part (CTb) extending the first part (CTa), turned towards the foot (22) of the pole (10), and comprising at least two rows resting on at least two superimposed layers (C2, C3, C4) of levels lower than said last superimposed layer (C5).

6. Electric machine rotor (12) according to any one of the preceding claims, wherein said wound poles (10) define a definite space (E) configured to permit the passage of a winding needle to the foot (22) of said poles (10).

7. Rotor (12) of an electric machine according to the preceding claim, wherein said space (E) extends at least radially at the right of a determined clearance (J) between the feet (22) of the poles (10).

8. Electric machine rotor (12) according to any one of claims 6 or 7 taken in combination with claims 3 and 5, wherein the number (N) of levels and the rank decay ratio (Rn) are configured so that each winding (18) is at a distance from said space (E).

9. Rotor (12) of an electric machine according to any one of the preceding claims, wherein each winding (18) is of the orthocyclic type, each turn being arranged in a staggered fashion with at least two other turns in contact with said turn.

10. Electric machine, comprising a rotor according to any one of claims 1 to 9.

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