Leg-shaped pole rotor and electrically excited synchronous machine for a motor vehicle

Abstract

A salient-pole rotor (1) for a current-excited synchronous machine (20) is provided. The salient-pole rotor (1) comprises a rotor yoke (2), several salient poles (3) formed circumferentially on the rotor yoke (2), each salient pole having a pole core (3.2) and a pole shoe (3.1), and several main excitation coils (10) wound around a pole core (3.2) of the several salient poles (3.1, 3.2). The salient pole rotor (1) comprises several secondary exciter arrangements (12), each having a metal core (12.1) and a first secondary exciter coil (12.2) wound around the metal core (12.1), wherein the respective pole shoe (3.1) of the several salient poles (3) each has at least one receiving pocket in which one of the several secondary exciter arrangements (12) is received.

Description

[0001] The present disclosure relates to a salient pole rotor, a current-excited synchronous machine having the salient pole rotor, and / or a motor vehicle having the current-excited synchronous machine.

[0002] Electric machines can be used in motor vehicles, for example, as traction motors. Various types of electric machines are known, such as synchronous motors. These include single-phase and three-phase synchronous machines in motor mode, in which a constantly magnetized rotor (or armature) is driven synchronously by a moving rotating magnetic field in the stator during normal operation. The energy provided by the magnetic interaction between the stator and the rotor can be tapped via the rotation of the rotor and used, for example, to drive the electrically powered motor vehicle or another machine in the vehicle.

[0003] In externally excited or current-excited electrical machines, the respective rotor also has rotor windings that can be supplied with current, whereby the rotor can, for example, be manufactured in a salient pole design, i.e. it has salient poles that project radially outwards and are wound by the rotor windings.

[0004] In a typical salient pole topology, the shaft (or pole core) of the salient pole is highly (magnetically) saturated during operation, so a higher magnetic flux through the rotor core would only be possible with a wider salient pole shaft. However, the width of the shaft is limited by the required number of turns of the excitation coil(s). This often requires, especially during high-load operation, the desired magnetic flux to be achieved by applying a disproportionately high current. This is only accompanied by significant electrical losses, which reduce efficiency in this operating range.

[0005] CN 113364156 A describes a brushless electromagnetic synchronous motor with an additional rotor yoke, wherein a stator part of the motor comprises a stator core and a stator armature winding, and wherein a rotor part of the motor comprises a rotor core, a rotating shaft, a rotor AC winding, a rotor DC excitation winding, a magnetic conduction bridge and a rotating rectifier.

[0006] WO 2021 / 067713 A1 describes a rotor for a wound-field synchronous machine, comprising a core with an annular cross-section extending between an outer surface and an inner surface defining a bore. The rotor also includes a plurality of field windings spaced at regular angular intervals, each extending around the base of the core, adjacent to the outer surface, and through the bore. The field windings of the rotor are arranged radially or spoke-like.

[0007] EP 2 784 918 A1 describes a rotating electric machine comprising a stator for generating a rotating magnetic field, a rotatable rotor, diode devices connected to coils, the coils being wound on the rotor and arranged to rotate with the rotor, and a cooling structure for cooling the diode devices by means of a cooling oil supplied from the inside in a radial direction with respect to the diode devices.

[0008] Against the background of this prior art, the object of the present disclosure is to provide a device and / or a method which are each suitable for enriching the prior art.

[0009] The problem is solved by the features of the independent claims. The subordinate claims and the dependent claims each contain optional developments of the disclosure.

[0010] The task is then solved by a salient pole rotor for a current-excited (or separately excited) synchronous machine.

[0011] The salient-pole rotor comprises a rotor yoke and a plurality of salient poles formed on the rotor yoke (e.g., at regular intervals from one another) in the circumferential direction (e.g., of the rotor yoke and / or the salient-pole rotor). The plurality of salient poles each have a pole core and a pole shoe.

[0012] The salient pole rotor comprises several main excitation coils, each wound around a pole core of the several salient poles.

[0013] The salient-pole rotor comprises a plurality of auxiliary excitation assemblies, each having a metal core (e.g., an iron core) and a first auxiliary excitation coil wound around the metal core. The respective pole piece of the plurality of salient poles each has at least one receiving pocket in which one of the plurality of auxiliary excitation assemblies is accommodated.

[0014] The salient-pole rotor described above offers a number of advantages. Among other things, it provides a topology for a salient-pole rotor with a pole core-optimized design and an optimized configuration of the excitation coils, which leads to an increase in the performance and efficiency of the salient-pole rotor and thus also of the current-excited electrical machine during operation.

[0015] For example, the (first) auxiliary excitation coils can each be arranged along a magnetic flux path in the salient poles, with the division of the main and auxiliary excitation coils leading, for example, to a reduction in the number of windings of the main excitation coils around the pole cores. This makes it possible, for example, to design pole cores wider than in conventional salient-pole rotors, so that a desired magnetic flux can be advantageously adjusted with a lower current than in conventional salient-pole rotors. Accordingly, electrical losses can be reduced and the power efficiency of the salient-pole rotor or the electrical machine with the salient-pole rotor can be increased.

[0016] Furthermore, the distribution of the excitation coils along the path of the magnetic flux can advantageously enable a larger-area cooling of the excitation coils.

[0017] Possible further developments of the salient pole rotor described above are explained in detail below.

[0018] The rotor yoke and the multiple salient poles may be formed by a laminated core. The respective metal core of each of the multiple secondary excitation assemblies may be a magnetically conductive core (e.g., an iron core), which may be constructed in one piece or from many individual laminations and / or from a soft magnetic compound (SMC).

[0019] The rotor yoke can be ring-shaped and / or have a (central) shaft receiving opening (for receiving a rotor shaft).

[0020] The respective receiving pocket can extend in the axial direction of the salient pole rotor and can be open or openable only at at least one axial end of the receiving pocket.

[0021] The respective receiving pocket can be designed such that one of the several secondary excitation arrangements can be pushed into the receiving pocket during assembly (optionally only) in the axial direction of the salient pole rotor.

[0022] The multiple secondary excitation assemblies can each be accommodated in the respective receiving pocket without additional fixations (or without separate fixing elements). It is conceivable that the multiple secondary excitation assemblies can each be clamped (or accommodated in a clamped manner) in the respective receiving pocket.

[0023] The respective pole piece can have (optionally exactly) two receiving pockets, which can be mirror-symmetrical to each other with respect to a central axis of the pole piece. The central axis can run in the radial direction of the salient pole rotor.

[0024] Two of the multiple auxiliary excitation arrangements can be accommodated in the respective pole piece, which can be arranged mirror-symmetrically to each other with respect to the central axis of the pole piece. The two of the multiple auxiliary excitation arrangements can be arranged obliquely to the central axis (e.g., in a cross-section of the salient pole rotor).

[0025] The respective pole piece can have two end sections that protrude beyond the respective pole core in the circumferential direction of the salient pole rotor (optionally on both sides and / or on opposite sides of the pole piece). A receiving pocket can be formed at least partially in each of the two end sections and / or one of the multiple secondary excitation arrangements can be accommodated at least partially.

[0026] The plurality of main excitation coils and the first secondary excitation coils of the plurality of secondary excitation arrangements may be DC coils and / or may each be supplied with a DC current.

[0027] The salient-pole rotor may comprise a plurality of second auxiliary excitation coils, each of which may be wound around the rotor yoke between two of the plurality of salient poles. The plurality of second auxiliary excitation coils may be DC coils and / or each capable of receiving a direct current.

[0028] The plurality of second auxiliary excitation coils can each partially overlap at least one of the plurality of main excitation coils in the radial direction of the salient pole rotor and / or be arranged at least partially in front of at least one of the plurality of main excitation coils.

[0029] Furthermore, it is conceivable that the salient pole rotor may comprise a plurality of third auxiliary excitation coils, each of which is wound around the pole piece of one of the plurality of salient poles.

[0030] Exactly two of the secondary excitation arrangements can be accommodated in each of the plurality of salient poles. Exactly one of the plurality of second secondary excitation coils can be arranged between each two of the plurality of salient poles, and / or exactly one of the plurality of second secondary excitation coils can be arranged in all gaps formed by each two of the plurality of salient poles.

[0031] The first secondary excitation coils can each have a width and height (in a cross-section of the salient pole rotor) that are at least a factor of 2, optionally at least a factor of 4, smaller than a respective width and height of the main excitation coils (in the cross-section of the salient pole rotor).

[0032] The above description can be summarized in other words and in a possible more concrete embodiment of the disclosure as described below, whereby the following description is not to be interpreted as limiting the disclosure.

[0033] (Secondary) excitation coils can be arranged along a magnetic flux path in the salient-pole rotor. Distributing the excitation coils can reduce the number of turns around the shaft regions (or pole cores) of the salient pole. This can make it possible to make the shaft regions (or pole cores) of such a salient-pole topology as wide as possible. Additional secondary excitation coils can be wound around the respective head of the salient pole, i.e., around the pole piece, or around the yoke of the rotor core. A further advantage of this distribution of the excitation coils along the magnetic flux path can be that it allows for larger-area cooling of the excitation coils.

[0034] Furthermore, a current-excited synchronous machine (SSM for short) for a motor vehicle is provided, which comprises the salient pole rotor described above.

[0035] The current-excited synchronous machine may comprise a stator which surrounds the salient pole rotor at least circumferentially or in the circumferential direction.

[0036] The stator may have electrical windings (or coils) that can be supplied with alternating current and / or three-phase current to drive the salient pole rotor.

[0037] What has been described above with reference to the salient pole rotor also applies analogously to the current-excited synchronous machine and vice versa.

[0038] Furthermore, a motor vehicle is provided which comprises the above-described current-excited synchronous machine and / or the above-described salient pole rotor.

[0039] The motor vehicle can be an electrically driven, e.g., mobile, motor vehicle. The current-excited synchronous machine can be designed as the motor vehicle's traction motor or traction machine.

[0040] The motor vehicle may comprise an electrical source, e.g. a traction battery, for supplying the stator (or the windings of the stator) with electrical energy and / or with an alternating current via at least one converter.

[0041] The electrical source may be configured to supply the main excitation coils and the (first and optionally second) secondary excitation coils with electrical energy and / or with a direct current.

[0042] The motor vehicle may be a passenger car, in particular an automobile, or a commercial vehicle, such as a truck.

[0043] What has been described above with reference to the current-excited synchronous machine and the salient pole rotor also applies analogously to the motor vehicle and vice versa.

[0044] Below is an optional embodiment with reference to Fig. 1 described. Fig. 1 schematically shows a (upper) cross-sectional half of a current-excited synchronous machine according to the disclosure with a salient pole rotor.

[0045] Fig. 1 shows only a schematic and partial view of the current-excited synchronous machine 20, e.g., for a motor vehicle, with only the upper cross-sectional half of the current-excited synchronous machine 20 being shown. The lower cross-sectional half can be designed analogously.

[0046] The current-excited synchronous machine 20 comprises the salient-pole rotor 1 and the stator 5, with the stator 5 circumferentially surrounding the salient-pole rotor 1. For the purposes of the present disclosure, the salient-pole rotor 1 may constitute an independent protected object independent of the current-excited synchronous machine 20.

[0047] The salient pole rotor 1 comprises a rotor yoke 2 and a plurality of salient poles 3, which are formed, for example, at regular intervals from one another, in the circumferential direction on the rotor yoke 2, wherein the plurality of salient poles 3 each have a pole core 3.2 and a pole shoe 3.1. As shown in Fig. 1, the salient pole rotor 1 shown comprises three salient poles 3 in the upper cross-sectional half, so that the salient pole rotor 1 can comprise, for example, six salient poles 3 in total.

[0048] The rotor yoke 2 can be ring-shaped or has a central shaft receiving opening 4 for receiving a rotor shaft (not shown).

[0049] The salient pole rotor 1 comprises several main excitation coils 10, each wound around a pole core 3.2 of the several salient poles. Fig. In Figure 1, the main excitation coils 10 are represented in simplified form by rectangles, with each rectangle representing a plurality of windings arranged side by side and / or one above the other and wound around the respective pole core 3.2. Accordingly, the two rectangles to the left and right of the respective pole core 3.2 represent the same main excitation coil 10.

[0050] The salient pole rotor 1 comprises a plurality of auxiliary excitation assemblies 12, each having a metal core 12.1, e.g., an iron core, and a first auxiliary excitation coil 12.2 wound around the metal core 12.1. The respective pole piece 3.1 of the plurality of salient poles 3 each has at least one receiving pocket in which one of the plurality of auxiliary excitation assemblies 12 is accommodated.

[0051] Similar to the main excitation coils 10, the secondary excitation coils 12.2 are in Fig. 1 is simplified by black rectangles, where the rectangles each represent a plurality of windings arranged side by side and / or one above the other and wound around the respective metal core 12.1. Accordingly, the two rectangles to the left and right of the respective metal core 12.1 represent the same secondary excitation coil 12.2.

[0052] The respective receiving pocket can extend in the axial direction of the salient pole rotor 1 and can be open or openable only at at least one axial end of the receiving pocket. In other words, the respective receiving pocket can be designed such that one of the plurality of auxiliary excitation assemblies 12 can be pushed into the receiving pocket during assembly in the axial direction of the salient pole rotor 1. Furthermore, the plurality of auxiliary excitation assemblies 12 can each be accommodated in the respective receiving pocket without additional fixings.

[0053] As in Fig. As shown in Figure 1, the respective pole piece 3.1 of the plurality of salient poles 3 can each have two receiving pockets that are mirror-symmetrical to one another with respect to a central axis of the pole piece 3.1, which runs in the radial direction of the salient pole rotor 1. (Exactly) two of the plurality of secondary excitation assemblies 12 can be accommodated in the respective pole piece 3.1, which can be arranged mirror-symmetrically to one another with respect to the central axis of the pole piece 3.1.

[0054] Alternatively, or additionally, the respective pole shoe 3.1 can have two end sections which project beyond the respective pole core 3.2 on both sides in the circumferential direction of the salient pole rotor 1, wherein a receiving pocket can be formed at least in sections in each of the two end sections and / or one of the plurality of secondary excitation arrangements 12 can be accommodated at least in sections.

[0055] In addition to the first auxiliary excitation coils 12.1, the salient-pole rotor 1 can comprise a plurality of second auxiliary excitation coils 13, each of which can be wound around the rotor yoke 2 between two of the plurality of salient poles 3. The plurality of second auxiliary excitation coils 13 can, for example, each partially overlap at least one of the plurality of main excitation coils 10 in the radial direction of the salient-pole rotor 1.

[0056] The plurality of main excitation coils 10, the first auxiliary excitation coils 12.2 of the plurality of auxiliary excitation arrangements 12 and the plurality of second auxiliary excitation coils 13 may be DC coils. List of reference symbols 1 salient pole rotor 2 rotor yoke 3 salient poles 3.1 Pole shoes of the salient poles 3.2 Pole cores of the salient poles 4 Shaft receiving opening of the rotor yoke 5 Stator 10 main excitation coils 12 auxiliary excitation arrangements 12.1 Metal cores of the secondary excitation arrangements 12.2 (first) secondary excitation coils of the secondary excitation arrangements 13 second auxiliary excitation coils 20 current-excited synchronous machines QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] CN 113364156 A

[0005] WO 2021 / 067713 A1

[0006] EP 2 784 918 A1

[0007]

Claims

[1] Salient pole rotor (1) for a current-excited synchronous machine (20), the salient pole rotor (1) comprising: - a rotor yoke (2); - a plurality of salient poles (3) formed in the circumferential direction on the rotor yoke (2), wherein the plurality of salient poles (3) each have a pole core (3.2) and a pole shoe (3.1); and - several main excitation coils (10), each wound around a pole core (3.2) of the several salient poles (3), characterized by that the salient pole rotor (1) comprises: - a plurality of auxiliary excitation arrangements (12), each having a metal core (12.1) and a first auxiliary excitation coil (12.2) wound around the metal core (12.1), wherein the respective pole shoe (3.1) of the plurality of salient poles (3) each has at least one receiving pocket in which one of the plurality of auxiliary excitation arrangements (12) is received. [2] Salient pole rotor (1) according to claim 1, characterized by , that - the respective receiving pocket extends in the axial direction of the salient pole rotor (1) and is open or openable only at at least one axial end of the receiving pocket, and / or - the respective receiving pocket is designed such that one of the plurality of secondary excitation arrangements (12) can be pushed into the receiving pocket during assembly in the axial direction of the salient pole rotor (1). [3] Salient pole rotor (1) according to claim 1 or 2, characterized by that the plurality of secondary excitation arrangements (12) are each accommodated in the respective receiving pocket without additional fixings. [4] Salient pole rotor (1) according to one of claims 1 to 3, characterized by , that - the respective pole shoe (3.1) has two receiving pockets which are mirror-symmetrical to one another with respect to a central axis of the pole shoe (3.1) which runs in the radial direction of the salient pole rotor (1); and / or - two of the plurality of secondary excitation arrangements (12) are accommodated in the respective pole shoe (3.1), which are arranged mirror-symmetrically to one another with respect to the central axis of the pole shoe (3.1). [5] Salient pole rotor (1) according to one of claims 1 to 4, characterized by that the respective pole shoe (3.1) has two end sections which project beyond the respective pole core (3.2) in the circumferential direction of the salient pole rotor (1), wherein a receiving pocket is formed at least in sections in each of the two end sections and / or one of the plurality of secondary excitation arrangements (12) is received at least in sections. [6] Salient pole rotor (1) according to one of claims 1 to 5, characterized by that the plurality of main excitation coils (10) and the first secondary excitation coils (12.2) of the plurality of secondary excitation arrangements (12) are DC coils. [7] Salient pole rotor (1) according to one of claims 1 to 6, characterized bythat the rotor yoke (2) is ring-shaped and the salient pole rotor (1) comprises: - a plurality of second secondary excitation coils (13), each wound around the rotor yoke (2) between two of the plurality of salient poles (3). [8] Salient pole rotor (1) according to claim 7, characterized by that the plurality of second auxiliary excitation coils (13) each partially overlap at least one of the plurality of main excitation coils (10) in the radial direction of the salient pole rotor (1). [9] Current-excited synchronous machine (20) for a motor vehicle, characterized by that the current-excited synchronous machine (20) comprises the salient pole rotor (1) according to one of claims 1 to 8. [10] Motor vehicle, characterized by that the motor vehicle comprises the current-excited synchronous machine (20) according to claim 9.

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