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), each wound around a pole core (3.2) of the several salient poles (3). The salient-pole rotor (1) comprises several secondary excitation assemblies (11), each having a metal core (11.1) and a secondary excitation coil (11.2) wound around the metal core (11.1), each salient pole (3.1, 3.2) having a receiving pocket in which one of the several secondary excitation assemblies (11) 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] DE 11 2015 001 950 T5 describes a rotating electric machine comprising a plurality of salient poles on a rotor projecting toward a stator and receiving an additional current to generate a torque to rotate the rotor relative to the stator, and a plurality of auxiliary poles on the rotor arranged between the salient poles along the rotation direction of the salient poles to generate an additional current, thereby causing the salient poles to generate a torque.

[0006] DE 10 2020 129 142 A1 describes a rotor for a permanent magnet-free synchronous machine, with a magnetic unit which has a base body and is designed to provide alternating magnetic poles in the circumferential direction on the air gap side, wherein each magnetic pole is assigned a winding section of an excitation winding of the rotor arranged on the base body.

[0007] DE 10 2021 121 626 A1 describes a rotor for an electrical machine, with at least one rotor laminated core having at least one coil receiving opening, with at least one coil device arranged in the at least one coil receiving opening and with at least one holding device joined to the rotor laminated core and preventing a centrifugal force-induced movement of the at least one coil device outwards and out of the at least one coil receiving opening in the radial extension direction of the rotor during use of the electrical machine.

[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 multiple salient poles. The respective main excitation coils can be conveniently combined in a wiring unit and thus electrically connected. This creates a rotor winding that can then be electrically energized.

[0013] The salient-pole rotor comprises a plurality of secondary excitation assemblies, each having a metal core (e.g., an iron core) and a secondary excitation coil wound around the metal core. The plurality of salient poles each have a receiving pocket in which one of the plurality of secondary 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 auxiliary excitation coils can be used to handle low-load operation, at least to a certain extent, using the auxiliary excitation coils alone. The reduced conductor length of the auxiliary excitation coils can advantageously result in lower electrical losses, for example. In other words, the main excitation coils can be designed so that the synchronous machine is optimally efficient, but the (high) torque requirements can also be met via the additional auxiliary excitation coils.

[0016] Possible further developments of the salient pole rotor described above are explained in detail below.

[0017] The rotor yoke and the multiple salient poles can be formed by a laminated core. The respective metal core of each of the multiple secondary excitation assemblies can be formed by a (secondary excitation) laminated core. The respective metal core can be a magnetically conductive core, e.g., an iron core constructed from a single piece or from many individual laminations, or from a soft magnetic compound (SMC).

[0018] The rotor yoke can be ring-shaped and / or have a (central) shaft receiving opening (for receiving a rotor shaft).

[0019] The main excitation coils and the secondary excitation coils can be DC coils and / or can be supplied with a DC current.

[0020] The respective receiving pocket can extend in the axial direction of the salient pole rotor. It is conceivable for the respective receiving pockets to 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 multiple auxiliary excitation arrangements can each be arranged mirror-symmetrically to a central axis of one of the multiple salient poles (in which the respective one of the multiple auxiliary excitation arrangements is accommodated). The central axis can run in the radial direction of the salient pole rotor.

[0024] The plurality of auxiliary excitation arrangements may each have a winding direction of the respective auxiliary excitation coil, which may be oriented perpendicular to the central axis of one of the plurality of salient poles (in which the respective one of the plurality of auxiliary excitation arrangements is accommodated), wherein the central axis may extend in the radial direction of the salient pole rotor.

[0025] The plurality of secondary excitation arrangements can each be accommodated in a transition region of the respective pole core and pole shoe and / or in the respective pole shoe.

[0026] The multiple auxiliary excitation arrangements can be dimensioned for loss-optimized control of the main excitation coils and auxiliary excitation coils.

[0027] The multiple main excitation coils can be designed to optimize the efficiency of the current-excited synchronous machine. Torque requirements of the current-excited synchronous machine can also be covered by the auxiliary excitation coils.

[0028] Exactly one of the secondary excitation arrangements can be accommodated in each of the several salient poles.

[0029] The 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).

[0030] 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.

[0031] An additional excitation coil can be placed in the core of each salient pole. This coil can be wound around a separate iron core, which can be inserted into the laminated core from the outside, i.e., axially or along the rotor axis. The optimal dimensioning of this coil can be such that loss-optimized control of the respective coils (main excitation coil around the pole shaft or pole core and secondary excitation coil in the salient pole) is possible. For example, low-load operation can be handled, at least to a large extent, by the secondary coil alone. The advantage is that the reduced conductor length can result in lower electrical losses.

[0032] Furthermore, a current-excited synchronous machine (SSM for short) for a motor vehicle is provided, which comprises the salient pole rotor described above.

[0033] The current-excited synchronous machine may comprise a stator which surrounds the salient pole rotor at least circumferentially or in the circumferential direction.

[0034] 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.

[0035] What has been described above with reference to the salient pole rotor also applies analogously to the current-excited synchronous machine and vice versa.

[0036] Furthermore, a motor vehicle is provided which comprises the above-described current-excited synchronous machine and / or the above-described salient pole rotor.

[0037] 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.

[0038] 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.

[0039] The electrical source may be designed to supply the main excitation coils and the secondary excitation coils with electrical energy and / or with a direct current.

[0040] The motor vehicle may be a passenger car, in particular an automobile, or a commercial vehicle, such as a truck.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] The rotor yoke 2 can be ring-shaped or has a central shaft receiving opening 4 for receiving a rotor shaft (not shown).

[0047] 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.

[0048] The respective main excitation coils 10 are combined in a wiring unit and thereby electrically connected, creating a rotor winding which can then be electrically energized.

[0049] The salient pole rotor 1 further comprises a plurality of auxiliary excitation assemblies 11, each having a metal core 11.1, e.g., an iron core, and a auxiliary excitation coil 11.2 wound around the metal core 11.1. The plurality of salient poles 3 each have a receiving pocket in which one of the plurality of auxiliary excitation assemblies 11 is accommodated. Thus, exactly one of the auxiliary excitation assemblies 11 can be accommodated in each of the plurality of salient poles 3.

[0050] Similar to the main excitation coils 10, the secondary excitation coils 11.2 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 11.1. Accordingly, the two rectangles to the left and right of the respective metal core 11.1 represent the same secondary excitation coil 11.2.

[0051] As in Fig.As shown in Figure 1, the plurality of auxiliary excitation arrangements 11 can each be arranged mirror-symmetrically to a central axis of the salient pole 3, which extends in the radial direction of the salient pole rotor 1 and in which the respective auxiliary excitation arrangement 11 is accommodated. Alternatively, or additionally, the winding direction of the respective auxiliary excitation coil 11.2 can be oriented perpendicular to the central axis.

[0052] The plurality of secondary excitation arrangements 11 can each be accommodated in a transition region of the respective pole core 3.2 and pole shoe 3.1 and / or in the respective pole shoe 3.1.

[0053] It is conceivable that the multiple auxiliary excitation arrangements 11 can be dimensioned for loss-optimized control of the main excitation coils 10 and auxiliary excitation coils 11.2. Alternatively, or additionally, the multiple main excitation coils 10 can be designed for optimized efficiency of the current-excited synchronous machine 20, whereby torque requirements of the current-excited synchronous machine 20 can also be covered via the auxiliary excitation coils 11.2.

[0054] The respective receiving pocket can extend in the axial direction of the salient pole rotor 1. In other words, the respective receiving pocket can be designed such that one of the plurality of auxiliary excitation assemblies 11 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 11 can each be accommodated in the respective receiving pocket without additional fixings. 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 11 secondary excitation arrangements 11.1 Metal cores of the secondary excitation arrangements 11.2 Auxiliary excitation coils of the auxiliary excitation arrangements 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] DE 11 2015 001 950 T5

[0005] DE 10 2020 129 142 A1

[0006] DE 10 2021 121 626 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 (11), each comprising a metal core (11.1) and a auxiliary excitation coil (11.2) wound around the metal core (11.1), - wherein the plurality of salient poles (3) each have a receiving pocket in which one of the plurality of secondary excitation arrangements (11) 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 / or - the respective receiving pocket is designed such that one of the plurality of secondary excitation arrangements (11) 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 (11) 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 plurality of secondary excitation arrangements (11) are each arranged mirror-symmetrically to a central axis of one of the plurality of salient poles (3.1, 3.2), which runs in the radial direction of the salient pole rotor (1). [5] Salient pole rotor (1) according to one of claims 1 to 4, characterized bythat the plurality of secondary excitation arrangements (11) each have a winding direction of the respective secondary excitation coil (11.2) which is oriented perpendicular to a central axis of one of the plurality of salient poles (3), which runs in the radial direction of the salient pole rotor (1). [6] Salient pole rotor (1) according to one of claims 1 to 5, characterized by , that - the plurality of secondary excitation arrangements (11) are each accommodated in a transition region of the respective pole core (3.2) and pole shoe (3.1) and / or in the respective pole shoe (3.1) and / or - the plurality of main excitation coils (11) are designed for optimized efficiency of the current-excited synchronous machine (20), wherein torque requirements of the current-excited synchronous machine (20) are also covered via the secondary excitation coils (11.2). [7] Salient pole rotor (1) according to one of claims 1 to 6, characterized bythat the plurality of secondary excitation arrangements (11) are dimensioned for loss-optimized control of the main excitation coils (10) and secondary excitation coils (11.2). [8] Salient pole rotor (1) according to one of claims 1 to 7, characterized by that exactly one of the secondary excitation arrangements (11) is accommodated in each of the plurality of salient poles (3). [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.

Images