Radial flow rotor and electrically excited synchronous machine for a motor vehicle

Abstract

A radial flux rotor (1) is provided for a current-excited synchronous machine (20). The radial flux rotor (1) comprises a rotor lamination stack (2) having several cavities and several electromagnet assemblies (3), each of which is accommodated in one of the several cavities.

Description

[0001] The present disclosure relates to a radial flux rotor, a current-excited synchronous machine having the radial flux 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 machines or as auxiliary drives. 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.

[0003] 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 motor vehicle.

[0004] Rotors can have permanent magnets or electromagnets for constant magnetization, which are usually arranged in or on the laminated cores of the rotors.

[0005] However, these different options for magnetizing the rotors lead to higher costs due to additional lamination stack variants, both in terms of acquisition and production. Furthermore, different drive machines often require different production facilities, which both increases manufacturing costs and requires additional production space for drive manufacturing.

[0006] CN 106411087 A describes a triangular rotor power generation system comprising an eccentric shaft, a triangular rotor, and a cylinder block. The triangular rotor has a cavity inside, the cavity being provided with a magnetic yoke, and a rotor wrapping around the magnetic yoke.

[0007] KR 2003-0024644 A describes a rotor comprising core elements, each having a magnetic installation hole and a coil-forming hole. The core elements are arranged so that they can be stacked. A rotor coil is formed together with the coil-forming hole and attached to the stacked core elements. A magnet with a shaft insertion hole is embedded in the magnetic installation hole, which is connected by the rotating coil. A rotating shaft with a cooling hole is inserted into the shaft insertion hole of the magnet.

[0008] CN 209709886 U describes an axial magnetic field motor comprising a rear cover, a field frame assembly bolted into the rear cover, and a rotor assembly in the center of the field frame assembly. The field frame assembly includes a stator housing, a winding module secured to the inner cavity of the stator housing by high-temperature melting of the stator housing, a winding module extending through the stator housing, and a rotor assembly including a magnetic shoe, a rotor disk, an axle, and a bearing.

[0009] 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.

[0010] 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.

[0011] The task is then solved by a radial flux rotor for a current-excited (or separately excited) synchronous machine.

[0012] The radial flux rotor comprises a rotor core which has several cavities (also: hollow spaces and / or receiving pockets).

[0013] The radial flux rotor comprises several electromagnet arrangements, each of which is housed in one of the several cavities.

[0014] A radial flux rotor is a rotor with a magnetic flux in the radial direction of the radial flux rotor (or the current-excited synchronous machine). The winding direction of the excitation coils of the electromagnet arrangements expediently runs in a longitudinal direction of the radial flux rotor (or the current-excited synchronous machine) (to generate the magnetic flux).

[0015] The radial flux motor described above offers a number of advantages. Among other things, it provides a topology for a radial flux rotor for a current-excited synchronous machine, which, for example, can correspond in its basic topology to a permanent magnet rotor of a permanent magnet synchronous machine. This allows the multiple cavities originally designed for permanent magnets to be used instead for the electromagnet assemblies. Accordingly, common methods for securing the permanent magnets can also be used for the electromagnet assemblies. Overall, this advantageously reduces the number of rotor variants, for example.

[0016] Possible further developments of the radial flux motor described above are explained in detail below.

[0017] The rotor core may have a topology for a permanent magnet rotor and / or be designed for a permanent magnet rotor.

[0018] The radial flux rotor may include a rotor shaft. The rotor core may have a central shaft receiving opening in which the rotor shaft can be accommodated.

[0019] The rotor core can be ring-shaped and / or designed as a ring cylinder.

[0020] The plurality of electromagnet assemblies can each have a metal core and an excitation coil wound around the metal core. The respective metal core can be an iron core and / or formed by a laminated core (electromagnet). The respective excitation coil can consist of a copper wire, for example.

[0021] The plurality of electromagnet assemblies may each have an electrically insulating sheath surrounding the respective excitation coil.

[0022] The plurality of electromagnet arrangements can each be designed as a plug-in cassette.

[0023] The plurality of cavities may each extend in the axial direction of the radial flow rotor and may be open or openable only at at least one axial end.

[0024] The plurality of cavities can be designed such that the plurality of electromagnet arrangements can be pushed into one of the plurality of cavities during assembly (optionally only) in the axial direction of the radial flux rotor.

[0025] The plurality of electromagnet arrangements can each be accommodated in the plurality of cavities without additional (axial) fixations (or without separate fixing elements, securing devices and / or anchors).

[0026] The plurality of cavities and / or the plurality of electromagnet arrangements can be aligned obliquely and / or tangentially to a rotational axis of the radial flux rotor in a cross section of the rotor core.

[0027] The plurality of cavities and / or the plurality of electromagnet assemblies can be arranged in pairs. Two of the plurality of cavities and / or the plurality of electromagnet assemblies (forming a pair) can be arranged mirror-symmetrically to each other with respect to an axis extending in the radial direction of the radial flux rotor.

[0028] The radial flux rotor can comprise at least one permanent magnet accommodated in one of the plurality of cavities. The radial flux rotor can comprise a plurality of permanent magnets, each of which is accommodated in one of the plurality of cavities. One of the plurality of electromagnet assemblies or the at least one permanent magnet (or one of the plurality of permanent magnets) can be accommodated in each of the plurality of cavities. The radial flux rotor can, for example, have at least one pole with the at least one permanent magnet and poles with the plurality of electromagnet assemblies.

[0029] A combination of electromagnets and permanent magnets offers the advantage that the number of poles in the rotor can be controlled by controlling the electromagnets, resulting in increased efficiency, especially during low-load operation. Additionally, a boost function can be enabled, increasing the number of poles and thus significantly increasing the torque that can be generated, for example.

[0030] The multiple cavities can be of the same design.

[0031] The plurality of electromagnet arrangements and the at least one permanent magnet may have the same cross-section (and / or the same external dimensions).

[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] The present disclosure relates, among other things, to a topology for an SSM rotor (SSM: current-excited synchronous machine), which can correspond in its basic topology to a PSM rotor (PSM: permanent magnet synchronous machine). For example, an electromagnet can generate a magnetic flux and thus replace a permanent magnet. Sheet metal packages (wrapped with copper wire) can also be introduced into the cavities for a permanent magnet and generate a magnetic flux, allowing an electrical machine to operate.

[0034] For this purpose, coils can be wound around an iron core and coated with a layer to form an electrical insulation layer. This component can be considered a type of plug-in cassette.

[0035] These insert cassettes can be inserted into the cavities of a rotor core and secured using common methods (known from PSM technology). The power supply for the individual coils can be implemented in a similar way to the well-known SSM technology. This technology can take advantage of the fact that PSM rotors often have very large cavities, which can be used for the coils.

[0036] The advantage of this configuration can be that the same rotor lamination can be used as in a PSM configuration, thus reducing the number of rotor variants. Furthermore, it can be possible to join and fix the plug-in cassettes using the same (automated) system for joining and fixing the magnets. This saves production space and thus costs and enables flexible production. Due to the generally low installation height, this SSM rotor topology is primarily suitable for auxiliary drives that are used only as an additional drive.

[0037] Furthermore, a current-excited synchronous machine (SSM for short) for a motor vehicle is provided, which comprises the radial flux rotor described above.

[0038] The current-excited synchronous machine may comprise a stator which surrounds the radial flux rotor at least circumferentially or in the circumferential direction.

[0039] The stator may have electrical windings (or coils) that can be supplied with alternating current and / or three-phase current to drive the radial flux rotor.

[0040] What has been described above with reference to the radial flux rotor also applies analogously to the current-excited synchronous machine and vice versa.

[0041] Furthermore, a motor vehicle is provided which comprises the above-described current-excited synchronous machine and / or the above-described radial flux rotor.

[0042] The motor vehicle can be at least partially electrically driven, e.g., a mobile vehicle. The current-excited synchronous machine can be designed as an auxiliary drive (or power take-off) of the motor vehicle.

[0043] 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.

[0044] The electrical source can be designed to supply the excitation coils with electrical energy and / or with a direct current.

[0045] The motor vehicle may be a passenger car, in particular an automobile, or a commercial vehicle, such as a truck.

[0046] What has been described above with reference to the current-excited synchronous machine and the radial flux rotor also applies analogously to the motor vehicle and vice versa.

[0047] 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 radial flux rotor.

[0048] Fig. Figure 1 shows only a schematic and partial view of the current-excited synchronous machine 20, 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.

[0049] The current-excited synchronous machine 20 can be designed as a drive machine, e.g. as an additional drive, of a motor vehicle.

[0050] The current-excited synchronous machine 20 comprises the radial flux rotor 1 and the stator 5, with the stator 5 circumferentially surrounding the radial flux rotor 1. For the purposes of the present disclosure, the radial flux rotor 1 may constitute an independent protected object independent of the current-excited synchronous machine 20.

[0051] The radial flux rotor 1 comprises a rotor core 2 having a plurality of cavities and a plurality of electromagnet assemblies 3, each of which is housed in one of the plurality of cavities. The rotor core 2 is annular or formed as a ring cylinder.

[0052] The radial flux rotor 1 further comprises a rotor shaft 4, which is received in a central shaft receiving opening of the rotor core 2

[0053] The plurality of electromagnet assemblies 3 each comprise a metal core 3.1 and an excitation coil 3.2 wound around the metal core 3.1 in the longitudinal direction of the radial flux rotor 1. The plurality of electromagnet assemblies 3 may further comprise an electrically insulating sheath surrounding the respective excitation coil 3.2.

[0054] The plurality of electromagnet arrangements 3 can further be designed, for example, as a plug-in cassette, ie as a pre-assembled module that can be pushed into one of the plurality of cavities.

[0055] The plurality of cavities can each extend in the axial direction of the radial flux rotor 1 and be open or openable only at at least one axial end. In other words, the plurality of cavities can be configured such that the plurality of electromagnet assemblies 3 can be pushed into one of the plurality of cavities during assembly in the axial direction of the radial flux rotor 1.

[0056] As in Fig.1, the plurality of cavities and / or the plurality of electromagnet arrangements 3 in the shown cross-section of the rotor core 2 can be aligned obliquely and / or tangentially to a rotational axis of the radial flux rotor 1. Alternatively, or additionally, the plurality of cavities and / or the plurality of electromagnet arrangements 3 can be arranged in pairs, wherein two of the plurality of cavities and / or the plurality of electromagnet arrangements 3 forming a pair can be arranged mirror-symmetrically to one another with respect to an axis running in the radial direction of the radial flux rotor 1.

[0057] It is conceivable that not all of the plurality of cavities contain one of the plurality of electromagnet arrangements 3, but the radial flux rotor 1 further comprises at least one permanent magnet which is accommodated in one of the plurality of cavities.

[0058] The plurality of electromagnet arrangements 3 and the at least one permanent magnet can have the same dimensions or at least the same cross-section in order to be able to be accommodated in the plurality of, for example, identically designed, cavities. List of reference symbols 1 radial flux rotor 2 rotor lamination pack 3 electromagnet arrangements 3.1 Metal cores of the electromagnet arrangements 3.2 Excitation coils of the electromagnet arrangements 4 Rotor shaft 5 Stator 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 106411087 A

[0006] KR 2003-0024644 A

[0007] CN 209709886 U

[0008]

Claims

[1] Radial flux rotor (1) for a current-excited synchronous machine (20), the radial flux rotor (1) comprising: - a rotor lamination stack (2) having a plurality of cavities; characterized by that the radial flux rotor (1) comprises: - a plurality of electromagnet arrangements (3), each of which is accommodated in one of the plurality of cavities. [2] Radial flux rotor (1) according to claim 1, characterized by that the plurality of electromagnet arrangements (3) each have: - a metal core (3.1); - an excitation coil (3.2) wound around the metal core (3.1); and - an electrically insulating sheath surrounding the respective excitation coil (3.2). [3] Radial flux rotor (1) according to claim 2, characterized by that the plurality of electromagnet arrangements (3) are each designed as a plug-in cassette. [4] Radial flux rotor (1) according to one of claims 1 to 3, characterized by , that - the plurality of cavities each extend in the axial direction of the radial flow rotor (1) and are open or openable only at at least one axial end, and / or - the plurality of cavities are designed such that the plurality of electromagnet arrangements (3) can be pushed into one of the plurality of cavities during assembly in the axial direction of the radial flux rotor (1). [5] Radial flux rotor (1) according to one of claims 1 to 4, characterized by that the plurality of cavities and / or the plurality of electromagnet arrangements (3) in a cross section of the rotor core (2) - are aligned obliquely and / or tangentially to a rotational axis of the radial flux rotor (1), and / or - are arranged in pairs, wherein two of the plurality of cavities and / or the plurality of electromagnet arrangements (3) are arranged mirror-symmetrically to one another with respect to an axis which runs in the radial direction of the radial flux rotor (1). [6] Radial flux rotor (1) according to one of claims 1 to 5, characterized by that the radial flux rotor (1) comprises: - at least one permanent magnet which is accommodated in one of the plurality of cavities, wherein one of the plurality of electromagnet arrangements (3) or the at least one permanent magnet is accommodated in each of the plurality of cavities. [7] Radial flux rotor (1) according to claim 6, characterized by that the plurality of cavities are of identical design and / or the plurality of electromagnet arrangements (3) and the at least one permanent magnet have the same cross-section. [8] Current-excited synchronous machine (20) for a motor vehicle, characterized bythat the current-excited synchronous machine (20) comprises the radial flux rotor (1) according to one of claims 1 to 7. [9] Motor vehicle, characterized by that the motor vehicle comprises the current-excited synchronous machine (20) according to claim 8. [10] Motor vehicle according to claim 9, characterized by that the current-excited synchronous machine (20) is designed as an additional drive of the motor vehicle.

Images