Method for winding a motor rotor

Abstract

The invention relates to a wound rotor (20), in particular for an electric machine (30), the wound rotor (20) comprising a shaft (21) having a main axis (A), the shaft (21) comprising a manifold (22), the wound rotor (20) comprising a winding wire (25) and n magnetic poles (1, 2, 3, …, n-2, n-1, n) ordered and wound in ascending numerical order by rotating around the main axis (A), in particular n wound magnetic poles (1, 2, 3, …, n-2, n-1, n) distributed radially around the main axis (A), the n magnetic poles being successively wound by the wire (25) in ascending numerical order, whereas the last magnetic pole (n) is not the last to be wound.

Description

Technical Field

[0001] This invention relates to a wound rotor for an electric motor. It also relates to an electric motor including such a wound rotor. Furthermore, it relates to a vehicle including such a wound rotor and / or such an electric motor. Finally, it relates to a method for obtaining such a wound rotor. Background Technology

[0002] Electric motors, especially traction motors for motor vehicles, may include wound rotors. Such wound rotors typically include a shaft, slip rings, and multiple magnetic poles wound with wire. The wire (usually enameled copper) is wound on a bundle or stack of sheets. To allow current to flow through the coil, the ends of the copper wire are connected to the slip rings by hooks. These slip rings allow electrical energy to pass between the stationary portion and the wound rotor (rotating portion).

[0003] The winding channel or path at the groove and / or to the vicinity of the connector of such shaft and / or such slip ring is critical.

[0004] Specifically, poor wiring from the winding wire to the connector can lead to incorrect wire positioning in the connector hook. This can then result in residual stress in the connector (tension in the wire and connector, typically caused by crimping the wire to the hook) and / or rotational mechanical stress (centrifugal force). Poor crimping of the wire can also cause the wire to slip out of the hook. Hook opening and / or wire breakage and / or connector hook breakage may also occur.

[0005] Furthermore, this winding channel needs to be compatible with the complex methods used to produce the coils. The winding channel must allow the two ends of the winding to be reliably crimped at two hooks for connection. The winding channel must provide the winding with mechanical integrity suitable for operating stresses, especially centrifugal forces and / or vibrations. Summary of the Invention

[0006] The object of this invention is to provide a method for obtaining a wound rotor that overcomes the aforementioned disadvantages. Specifically, this invention allows for ensuring the mechanical robustness of the connection between the winding wires and the shaft and / or slip rings of the wound rotor.

[0007] To achieve this objective, the present invention relates to a wound rotor, particularly a wound rotor for an electric motor, the wound rotor comprising a shaft having a main axis, the shaft optionally including slip rings, the wound rotor comprising winding wire and n wound magnetic poles ordered in ascending numerical order obtained by rotation about the main axis, particularly n wound magnetic poles radially distributed about the main axis, the n magnetic poles being wound sequentially turn by turn according to their ascending numerical order, however the last magnetic pole is not the last magnetic pole to be wound.

[0008] The penultimate magnetic pole can be wrapped around the last magnetic pole.

[0009] The third-to-last magnetic pole is wrapped around the last magnetic pole.

[0010] Upstream of the first magnetic pole, the wire can rest against the axis at a first non-zero angle around the main axis.

[0011] Downstream of the last magnetic pole to be wound, the wire is placed against the axis at a second non-zero angle.

[0012] The wound rotor may include pins designed to facilitate wire winding, particularly between two adjacent magnetic poles and / or between each magnetic pole and the shaft and / or slip ring, especially pins extending parallel to or substantially parallel to the main axis.

[0013] The present invention further relates to an electric motor, particularly a vehicle traction motor, especially for motor vehicles, the electric motor comprising a wound rotor as defined above.

[0014] The present invention further relates to a vehicle, particularly a motor vehicle, which includes a wound rotor as defined above and / or an electric motor as defined above.

[0015] The present invention further relates to a method for obtaining a wound rotor as defined above, the method comprising the step of continuously winding n magnetic poles in ascending numerical order with wire, turn by turn, wherein the last magnetic pole is not the last magnetic pole to be wound. Attached Figure Description

[0016] These objects, features, and advantages of the present invention will be set forth in detail in the following description of some embodiments given in a non-limiting manner with reference to the accompanying drawings, in which:

[0017] Figure 1 This is a schematic diagram of a vehicle including an electric motor according to one embodiment, the electric motor including a four-pole wound rotor.

[0018] Figure 2 This is a schematic diagram of a six-pole wound rotor according to another embodiment.

[0019] Figure 3 This is a schematic diagram of an eight-pole wound rotor according to another embodiment. Detailed Implementation

[0020] Figure 1 A vehicle, such as a motor vehicle 40, is schematically illustrated according to one embodiment. According to one embodiment, the vehicle includes a motor 30, such as an electric motor providing traction and / or propulsion for the vehicle. According to one embodiment, the motor 30 includes a wound rotor 20. The wound rotor 20 includes a shaft 21 having a main axis A and a slip ring 22 (also referred to as a sliding ring). The slip ring 22 and the shaft 21 are assembled coaxially or substantially coaxially along the main axis A of rotation about which the wound rotor 20 is intended to rotate.

[0021] like Figure 1 , Figure 2 and Figure 3 The wound rotor 20 shown includes winding wire 25. Wire 25 is made of copper, for example (e.g., enameled copper).

[0022] More specifically, the wound rotor 20 includes n wound magnetic poles 1, 2, 3, ..., n-2, n-1, n. The n magnetic poles are preferably ordered in ascending numerical order obtained by rotating about the main axis A. Preferably, as shown in the figure, the n wound magnetic poles 1, 2, 3, ..., n-2, n-1, n are numbered, marked, or identified by assigning an increasing numerical order around the axis A clockwise, with each pole associated with a single number in the numerical order. Further, the n magnetic poles are distributed radially or substantially radially about the main axis A. The n magnetic poles are wound sequentially, turn by turn, in their ascending numerical order; however, the last magnetic pole n is not the last pole to be wound, as will be explained below.

[0023] Therefore, the first magnetic pole is associated with the number 1 in numerical order. The second magnetic pole is associated with the number 2 in numerical order. The third-to-last magnetic pole is associated with the number n-2 in numerical order. The second-to-last magnetic pole is associated with the number n-1 in numerical order. The last magnetic pole is associated with the number n in numerical order.

[0024] Therefore, the topological order of the magnetic poles defined above is different from the temporal order in which the magnetic poles are wound, as will be explained in more detail below.

[0025] Note that before winding, the first end 28 of the wire 25 is first secured to the first connecting device 26 arranged on the shaft 21 and / or slip ring 22.

[0026] Preferably, as shown in the figure, the first connecting device 26 is arranged on the side of the main axis A opposite to the magnetic pole 1. In other words, the first connecting device 26 is positioned near the magnetic pole that is positioned from the other side of the main axis A toward or substantially toward the magnetic pole 1.

[0027] The first connecting device 26 is, for example, a hook. Preferably, the first end 28 of the wire 25 is fixed to the first connecting device 26 or fixed at the first connecting device by heat pressing or cold pressing.

[0028] For example, the penultimate magnetic pole n-1 is wrapped around the last magnetic pole n. Therefore, for example, as... Figure 1 As shown, for a four-pole wound rotor with magnetic poles 1, 2, 3, and 4, magnetic pole 1 is wound first, then magnetic pole 2, then magnetic pole 4, and finally magnetic pole 3. Therefore, for example, as... Figure 2As shown, for a six-pole rotor with magnetic poles 1, 2, 3, 4, 5, and 6, magnetic pole 1 is wound first, then magnetic pole 2, then magnetic pole 3, then magnetic pole 4, then magnetic pole 6, and finally magnetic pole 5.

[0029] Alternatively, the penultimate magnetic pole n-2 is wound around, for example, after the last magnetic pole n (this is not shown).

[0030] Alternatively, the penultimate magnetic pole n-2 and the penultimate magnetic pole n-1 are wound around, for example, before the last magnetic pole n (this is not shown).

[0031] As a preferred option, especially in Figure 1 and Figure 3 As shown, before the wire reaches the first magnetic pole 1 to be wound at that pole, that is, upstream of the first magnetic pole 1 according to the winding direction, the wire 25 is supported against the shaft 21 and / or slip ring 22. In other words, before the first magnetic pole 1, the wire is supported on a portion 10 of the circumference of the shaft 21 and / or slip ring 22 (in... Figure 3 (Indicated by dashed lines). It rests at a first non-zero angle α about the main axis A, and the magnitude of this angle depends on the number of magnetic poles of the rotor. For example, as... Figure 3 The angle shown is greater than 45°. Contact needs to be provided, and then maximized.

[0032] Note that after winding n magnetic poles, the second end 29 of the wire 25 is attached to the second connecting device 27 arranged on the shaft 21 and / or slip ring 22.

[0033] Preferably, the second connecting device 27 is arranged on the side of the main axis A opposite to the first connecting device 26. In other words, the first connecting device 26 and the second connecting device 27 are arranged symmetrically or substantially symmetrically about the main axis A. Therefore, preferably, the second connecting device 27 is positioned near the magnetic pole 1.

[0034] The second connecting device 27 is, for example, a hook. Preferably, the second end 29 of the wire 25 is attached to the second connecting device 27 or attached to the second connecting device by heat or cold pressing.

[0035] Preferably, after the last wound magnetic pole and before reaching the second connecting device 27, i.e., downstream of the last wound magnetic pole along the winding direction, the wire 25 is rested against the shaft 21 and / or slip ring 22. In other words, after the last wound magnetic pole, the wire rests on a portion 11 of the circumference of the shaft 21 and / or slip ring 22 (in... Figure 3 (Indicated by dashed lines). The rest is located at a second non-zero angle β about the main axis A, and the magnitude of this angle depends on the number of magnetic poles the rotor has.

[0036] Advantageously, such as Figure 3 As shown, the rotor 20 includes pins 23 specifically designed to facilitate the winding of the wire 25. For example, at least one pin 23 is arranged between two adjacent magnetic poles and / or at least one pin 23 is arranged between each magnetic pole and the shaft 21 and / or slip ring 22. For example, as Figure 3 In the illustrated embodiment, two pins 23 are positioned near each magnetic pole, between each magnetic pole and shaft 21 and / or slip ring 22. Preferably, the pins 23 extend parallel to or substantially parallel to the main axis A.

[0037] The method used to obtain will now be described. Figure 3 One implementation of the method of the wound rotor 20 shown in the figure.

[0038] First, an unwound rotor with n magnetic poles and a winding wire 25 including a first end 28 and a second end 29 are obtained. The unwound rotor is pre-assembled with a shaft 21 having a main axis of rotation A and / or a slip ring 22. The unwound rotor is also provided with a first connecting device 26 and a second connecting device 27.

[0039] First, the first end 28 of the wire 25 is attached to the first connecting device 26 (e.g., by crimping). Then, the wire 25 is positioned against the shaft 21 and / or slip ring 22 at the angle portion 10 by bringing it close to the magnetic pole 1. In other words, the wire is brought to the opposite side of the first connecting device 26 relative to the main axis A. Preferably, in the case of a rotor equipped with a pin 23, the wire 25 is passed against at least one pin, for example, to orient the wire in a direction suitable for winding the magnetic pole 1, so that the magnetic pole will be wound around the wire 25.

[0040] Then, the step of winding the wire 25 around magnetic pole 1 is performed. The next process is the step of winding magnetic pole 2, which may be performed after the wire 25 has passed against one or more pins 23, such that the wire is oriented for winding magnetic pole 2 and / or for winding away from magnetic pole 1. The next process is the step of winding magnetic pole 3, which may be performed after the wire 25 has passed against one or more pins 23, such that the wire is oriented for winding magnetic pole 3 and / or for winding away from magnetic pole 2. The next process is the step of winding magnetic pole 4, which may be performed after the wire 25 has passed against one or more pins 23, such that the wire is oriented for winding magnetic pole 4 and / or for winding away from magnetic pole 3. The next process is the step of winding magnetic pole 5, which may be performed after the wire 25 has passed against one or more pins 23, such that the wire is oriented for winding magnetic pole 5 and / or for winding away from magnetic pole 4. The next process is the step of winding magnetic pole 6, which may be performed after the wire 25 has passed against one or more pins 23, such that the wire is oriented for winding magnetic pole 6 and / or for winding away from magnetic pole 5. The next process is the winding of the magnetic pole 8, which may be achieved after the wire 25 has passed against one or more pins 23, such that the wire is oriented for winding the magnetic pole 8 and / or for winding away from the magnetic pole 6. The next process is the winding of the magnetic pole 7, which may be achieved after the wire 25 has passed against one or more pins 23, such that the wire is oriented for resting against the shaft 21 and / or the slip ring 22 and / or for winding away from the magnetic pole 7.

[0041] Preferably, the "out" wire leaving the coil is offset from the "in" wire that begins winding the next coil in a direction parallel to or substantially parallel to the main axis A. For example, a low wall is constructed close to the side of the coil to ensure the distance between the "out" and "in" wires. Thus, preferably, the portions of the wire do not contact each other due to the offset at the locations where these portions leave and enter the coil. For example, the wire leading to the connection or hook crosses over other portions of the wire.

[0042] The wire 25 is then positioned such that it rests against the shaft 21 and / or slip ring 22 on the angled portion 11, thereby bringing the wire 25 closer to the magnetic pole 1, or in other words, closer to the side of the second connecting device 27. The next process is (e.g., using crimping) attaching the second end 29 of the wire 25 to the second connecting device 27.

[0043] Thus, the n magnetic poles are wound in ascending numerical order, one turn after another; however, the last magnetic pole n( Figure 3 In this case, magnetic pole 8) is not the last coil to be wound, but the second to last. The last magnetic pole to be wound is the second to last magnetic pole n-1.

[0044] For example, the winding of n magnetic poles is performed sequentially, one turn after another, in ascending numerical order, with the third-to-last magnetic pole n-2 being wound after the last magnetic pole n (not shown). For example, the winding of n magnetic poles is performed sequentially, one turn after another, in ascending numerical order, with magnetic pole n-3 being wound after the last magnetic pole n (not shown).

[0045] Through this invention, it is possible to obtain a six-pole rotor having six magnetic poles wound in the following magnetic pole order: 1, 2, 3, 4, 6, 5 or 1, 2, 3, 5, 6, 4 or 1, 2, 3, 6, 5, 4.

[0046] Through this invention, it is possible to obtain an eight-pole rotor having magnetic poles wound in the following magnetic pole order: 1, 2, 3, 4, 5, 6, 8, 7 or 1, 2, 3, 4, 5, 8, 6, 7 or 1, 2, 3, 4, 5, 8, 7, 6.

[0047] Generally, it is possible to obtain an n-pole rotor with magnetic poles wound in the following order: 1, 2, ..., n-2, n, n-1 or 1, 2, ..., n-3, n, n-1, n-2 or 1, 2, ..., n-3, n-1, n, n-2.

[0048] In summary, this solution allows the winding scheme to be modified to allow the wire to be tangent to the shaft and / or slip ring, or to increase the contact area, when the wire 25 leaves the first connector 26 and when the wire 25 reaches the second connector 27. For example, changing the winding order of the magnetic poles provides an angular return of approximately 45 degrees around the main axis A (that is, a counterclockwise return, where the magnetic poles are numbered clockwise), for the wire 25 to reach the second connector 27. Preferably, as previously stated, instead of simply being tangent to the shaft and / or slip ring, the resulting contact is tangent to the angular contact portion 10 when the wire leaves the first connector 26 and the angular contact portion 11 when the wire reaches the second connector 27.

[0049] Preferably, the contact of wire 25 at the angle portions 10, 11 is direct contact with the slip ring, particularly with the insulating portion of the slip ring (e.g., coated with plastic and / or made of plastic). Alternatively or additionally, an insulating sheath may be provided on the wire (particularly along the relevant length of the wire) to provide such insulation.

[0050] Furthermore, the opposing configuration of the connecting devices 26 and 27 relative to axis A results in a longer length of line 25 resting against the shaft or slip ring before and after winding.

[0051] Therefore, this solution significantly reduces the load on each angle support section 10, 11, ensuring mechanical robustness at each connection between the line and the slip ring and / or shaft.

[0052] This solution allows for the avoidance of relying on overmolding, a time-consuming, costly, and risky process. Specifically, during operation, if the overmolding material breaks, the thread may be cut.

[0053] This solution can be applied to motors with different polarities, for example, motors whose rotors include six magnetic poles, or even more than eight magnetic poles. Figure 1 As demonstrated, the solution is also compatible with motors including four-pole rotors to increase the contact area with the slip rings when necessary.

[0054] This solution avoids any improper wire positioning in the wiring relative to the connectors (first and second connectors). Residual stresses in the connectors (e.g., tension in the wire and connectors when the wire is attached to the hook by crimping) and / or rotational mechanical stresses (centrifugal force) are reduced, even if they cannot be eliminated. Since the wire positioning within each hook is optimal for the crimping operation, arbitrary slippage of the wire from the hook during crimping is prevented. This avoids any hook opening and / or wire breakage and / or connector hook breakage. Specifically, the angle at which the wire reaches the second connector 27 ensures that the wire remains at the closed end of the hook throughout the crimping process, which is crucial for crimp quality.

[0055] The winding method combined with part 11 provides improved repeatability of the winding position of the wire leaving the last magnetic pole being wound, especially due to the departure angle θ (in Figure 3 (As shown in the image) is smaller compared to the winding performed on the last magnetic pole that is being wound.

[0056] The winding solution provides the winding wire with mechanical integrity capable of withstanding operational stresses, particularly centrifugal forces associated with rotor rotation and / or vibration. Specifically, especially during rotor operation (i.e., rotation), the mechanical tension in the wire at the connectors is reduced. This is particularly achieved due to the wire contacting the slip ring before reaching the connecting device 27 for the second end 29 of the wire. Furthermore, the vibration behavior of the wire between the connectors 26, 27 and the pin 23 and / or the nearest winding is improved due to the support portions 10, 11. This results in reduced vibration transmission of the wire 25 at the connectors 26, 27, thereby eliminating the risk of wire breakage at the connection point.

[0057] Note that the solution according to the invention thus achieves the desired objective of ensuring the mechanical robustness of the connection between the winding wires and the shaft and / or slip rings of the wound rotor, and provides the following advantages:

[0058] - The cost is particularly low because the winding method is achieved with minimal or no modification to the wound rotor;

[0059] - The surrounding components are unaffected.

Claims

1. A wound rotor (20) comprising a shaft (21) having a main axis (A), the shaft (21) including slip rings (22), the wound rotor (20) including winding wires (25) and n magnetic poles (1, 2, 3, ..., n-2, n-1, n) ordered in ascending numerical order obtained by rotation about the main axis (A). Its features are, The n magnetic poles are wound sequentially, turn by turn, according to their ascending numerical order, but the last magnetic pole (n) is not the last magnetic pole to be wound.

2. The wound rotor (20) as described in claim 1, characterized in that, The penultimate magnetic pole (n-1) is wrapped around the last magnetic pole (n).

3. The wound rotor (20) as described in claim 1 or 2, characterized in that, The third-to-last magnetic pole (n-2) is wrapped around the last magnetic pole (n).

4. The wound rotor (20) as described in claim 1 or 2, characterized in that, Upstream of the first magnetic pole (1), the winding wire (25) rests against the axis (21) at a first non-zero angle (α) around the main axis (A).

5. The wound rotor (20) as described in claim 1 or 2, characterized in that, Downstream of the last magnetic pole (n-1, n-2) to be wound, the winding wire (25) rests against the axis (21) at a second non-zero angle (β) around the main axis (A).

6. The wound rotor (20) as described in claim 1 or 2, characterized in that, The wound rotor includes pins (23) for aiding in the winding of the winding wire (25).

7. The wound rotor (20) as described in claim 6, characterized in that, The pin (23) is arranged between two adjacent magnetic poles and / or between each magnetic pole and the shaft (21) and / or the slip ring (22).

8. The wound rotor (20) as described in claim 6, characterized in that, The pin (23) extends substantially parallel to the main axis (A).

9. The wound rotor (20) as claimed in claim 1, characterized in that, The n magnetic poles (1, 2, 3, ..., n-2, n-1, n) are radially distributed around the main axis (A).

10. An electric motor (30), characterized in that, The motor includes a wound rotor (20) as described in any one of claims 1 to 9.

11. The motor (30) as claimed in claim 10, characterized in that, This motor is a vehicle traction motor.

12. The motor (30) as claimed in claim 10, characterized in that, This motor is used in motor vehicles (40).

13. A vehicle, characterized in that, The vehicle includes a wound rotor (20) as described in any one of claims 1 to 9 or an electric motor (30) as described in claim 10.

14. The vehicle as claimed in claim 13, characterized in that, The vehicle is a motor vehicle (40).

15. A method for obtaining a wound rotor (20) as described in any one of claims 1 to 9, characterized in that, The method includes the step of continuously winding the n magnetic poles in ascending numerical order with the winding wire (25) turn by turn, however the last magnetic pole (n) is not the last magnetic pole to be wound.

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