Stator module and stator for an electrical rotating machine

Abstract

The invention relates to a stator module and a stator of an electrical rotating machine, and to an electrical rotating machine per se. The stator module of the electrical rotating machine comprises a plurality of coils (1, 2, 3), which are assigned to a plurality of phases and are arranged along a circumference, wherein coils (1, 2, 3) of the stator module each form a multilayer winding (40) of a conductor material wound around a stator tooth (20), and a respective phase supply line (44) of these coils (1, 2, 3) is produced on a turn (46) of the respective coil (1, 2, 3) adjacent to the stator tooth (20). The stator module, the stator and electrical rotating machine proposed here, provide technical solutions that enable highly efficient operation in a simple, space-saving and cost-effective manner.

Description

[0001] Stator module and stator for an electric rotating machine

[0002] The invention relates to a stator module and a stator for an electrical rotary machine, such as an axial flux machine, as well as the electrical rotary machine itself.

[0003] Electric drive motors are known from the state of the art in many industrial applications, and are also increasingly being used in the automotive industry. Such a motor comprises a stator and a rotor that rotates relative to it. The rotor typically includes a rotor shaft, balancing plates, rotor cores, and magnets.

[0004] Especially for applications in electrically powered vehicles, there is a requirement to achieve the required power within the available installation space. Accordingly, the electric rotating machine is often designed as an axial flux machine.

[0005] In electrically powered motor vehicles, the situation may arise that the axial flux machine is operated at different charge states of a motor vehicle battery, for example between 900 V and 230 V.

[0006] To limit the currents required for the required power, there is a trend toward higher operating voltages. For example, 400 V system voltages are established, with a strong trend toward 800 V systems. Voltage fluctuations due to the battery charge state are superimposed on these system voltages, so that, for example, an 800 V system can have operating voltages between 230 V and 900 V.

[0007] Furthermore, so-called voltage overshoots can occur, causing voltage increases of approximately 20% to 100% of the base voltage. In extreme cases, this situation can occur simultaneously with high temperatures and / or low atmospheric pressure, such as at high altitudes, which promote uncontrolled partial discharges. Because coils arranged adjacently around a circumference are usually assigned to different phases, very high voltages can exist between the coils, especially in these extreme situations. The coil insulation material must ensure appropriate insulation.

[0008] Different designs of axial flux machines therefore require, in addition to the insulator material, phase separators between the coils and / or special insulator materials or even particularly thick insulator wall thicknesses. However, both a phase separator and particularly thick insulator materials reduce the copper fill factor of the winding, complicate cooling of the conductors, and / or increase material and manufacturing costs.

[0009] Based on this, the present invention is based on the object of providing a stator module, a stator and an electric rotary machine that enable highly efficient operation in a simple, space-saving and cost-effective manner.

[0010] This object is achieved by the stator module according to claim 1, the stator according to claim 7, and the electric rotary machine according to claim 10. Advantageous embodiments of the stator module are specified in subclaims 2-6. Advantageous embodiments of the stator are specified in subclaims 8 and 9. An advantageous embodiment of the electric rotary machine is specified in subclaim 11.

[0011] The features of the claims can be combined in any technically reasonable manner, whereby the explanations from the following description as well as features from the figures can also be used to comprise additional embodiments of the invention.

[0012] The invention relates to a stator module of an axial flux machine, comprising several

[0013] Coils which are assigned to a plurality of phases and are arranged along a circumference, wherein coils of the stator module each form a multi-layer winding of a conductor material wound around a stator tooth, and a respective phase supply line of these coils is realized on a winding of the respective coil which is adjacent to the stator tooth.

[0014] One embodiment provides that the stator module has a single-tooth winding.

[0015] The stator tooth can be formed by an iron core.

[0016] The stator module can form a stator or just a module of a stator, such as an axial stator side. The multi-layer winding design means that the winding forms several radially adjacent layers of conductor material.

[0017] A winding adjacent to the stator tooth can also be understood as a winding that has the smallest radial distance to the center of the stator tooth, even if there is an intermediate layer between the stator tooth and the winding.

[0018] In the context of the present invention, the radial position refers to a rotational axis of a rotor of an electrical rotary machine equipped with the stator module or the stator. In the case of an axial flux machine, the rotational axis runs parallel to the longitudinal axis of the stator tooth.

[0019] The multiple layers of a winding have different distances from the iron core and from the neighboring coils. The radially innermost winding layer is located closest to the stator tooth and has the greatest distance from the neighboring coils. The adjacent and radially outermost winding layers have successively greater distances from the tooth and smaller distances from the neighboring coils. The radially outermost winding layer has the smallest distance from the neighboring coils.

[0020] Because the phase supply is made at the radially innermost winding layer, this winding layer also has the highest voltage potential. The subsequent winding layers have successively lower voltage potentials. The radially outermost winding layer therefore has the lowest voltage potential relative to the neighboring windings or coils.

[0021] Accordingly, the voltage between adjacent turns of two coils is minimized. This offers the possibility of using no phase separator or only a thin one, and / or reducing the wall thickness of the wire insulation or using cost-effective materials. A phase derivation of the respective coil can be implemented at the radially outermost turn of the coils.

[0022] Conductive material from turns of adjacent coils can be arranged in the same groove in some areas.

[0023] To further minimize the voltage between adjacent coils, coils of the same phase can be connected in parallel to at least one voltage source.

[0024] This can also be achieved by connecting these coils to phase outputs of an inverter.

[0025] Furthermore, at least one coil of each phase can be connected with its radially outermost turn to the star point of a star connection.

[0026] The windings can have insulation with a maximum thickness of 40 μm. In an advantageous embodiment, this thickness is a maximum of 30 μm, possibly only a maximum of 25 μm. The stator module can be designed for an operating voltage of 400 V or more.

[0027] The insulation material can be polyamide-imide. This means that the conductors can have thin wire insulation made of a cost-effective polyamide-imide.

[0028] Another aspect of the present invention is a stator of an electric rotary machine comprising at least one stator module constructed according to the above description.

[0029] This stator can, for example, comprise two described stator modules, wherein it is configured such that a rotor of the axial flux machine can be arranged axially between the stator modules, or such that the two stator modules are aligned on two opposite axial sides, so that the stator teeth point in opposite axial directions, and two rotors of the axial flux machine can be arranged axially on either side of the stator. The latter alternative refers to a so-called H-arrangement. Each of the stator modules can, for example, have coils with 42 to 62 turns each, such as 52 turns, which are separately connected to at least one voltage source.

[0030] Accordingly, no series connection is implemented in this embodiment. The potential of the outer windings is always close to the star point potential. Accordingly, a phase separator between adjacent coils is not necessary.

[0031] According to the present invention, an axial flux machine is further provided which has at least one stator module or a stator described above.

[0032] This axial flux machine can be designed for operating voltages in the range of 400 V or more.

[0033] The invention described above will be explained in detail below against the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention is in no way limited by the purely schematic drawings, and it should be noted that the embodiments shown in the drawings are not limited to the dimensions shown. It is shown in

[0034] Figure 1 : a schematic representation of the coil arrangement on a stator of an axial flux machine, and

[0035] Figure 2: a schematic representation of three adjacent coils coupled to different phases.

[0036] Figure 1 shows the general structure of the coil arrangement of the stator of an axial flux machine. It can be seen that along a circumference, several coils of the first phase 1, several coils of the second phase 2 and several coils of the third phase 3 are each combined in a coil group, wherein this coil group is arranged multiple times along the circumference, so that each coil 1, 2, 3 assigned to a phase is present six times in the embodiment shown here. In the embodiment shown here, phase separators 10 are arranged between coils 1, 2, 3 adjacent to one another along the circumference in order to prevent the occurrence of impermissible or undesired partial discharges between the coils 1, 2, 3.

[0037] Figure 2 shows a coil group comprising a first phase coil 1, a second phase coil 2 and a third phase coil 3.

[0038] For simplicity, these coils 1, 2, and 3 are not arranged along a curved circumference, but are shown linearly one behind the other. The structure of a coil is explained below using the coil of the first phase 1 as an example. The coil of the first phase 1 is formed by a winding 40 wound around a stator tooth 20, which can also be referred to as a stator tooth.

[0039] The longitudinal axis 21 of the stator tooth 20 extends perpendicular to the image plane shown.

[0040] The winding 40 shown here comprises three turns, namely a first turn 41, a second turn 42, and a third turn 43, although the stator module according to the invention is not limited to this number of turns. The first turn 41 is a turn 46 adjacent to the stator tooth 20 and thus forms the radially innermost turn 47 or radially innermost winding layer. The third turn 43 forms the radially outermost turn 48 or radially outermost winding layer.

[0041] A phase supply line 44 for the coil of the first phase 1 is formed on the first winding 41 or the winding 46 adjacent to the stator tooth, which forms the radially innermost winding 47.

[0042] At the third winding 43, which forms the radially outermost winding 48, a phase derivation 45 of the coil of the first phase 1 is formed. This means that a first three-phase current is applied to the coil of the first phase 1 at the radially innermost winding 47. The highest voltage potential is present at the radially innermost winding 47.

[0043] The other two coils of the respective other phases 2, 3 are connected to their respective phases in a corresponding manner. Facing sections of the windings 41, 42, 43 of adjacent coils 1, 2, 3 run together in a respective groove 30. By implementing the phase supply line 44 at the radially innermost winding 47 and the phase discharge line 45 at the radially outermost winding 48, the respective radially outermost windings 48 of the coils 1, 2, 3, which are closest to one another, exhibit the smallest voltage potential differences. Accordingly, in a respective slot 30 there is only a low voltage U between adjacent coils 1, 2, 3, which makes it possible to arrange the line elements of the windings 40 of the coils 1, 2, 3 with only thin-walled insulation and / or without phase separators 10, whereby the copper fill factor of the stator or the axial flux machine can be increased and thus the efficiency.

[0044] In the embodiment shown in Figure 2, the phase leads 45 of the coils 1, 2, 3 are connected in a star connection to a common star point 50. Accordingly, no series connection of the coils 1, 2, 3 is implemented here, which additionally reduces the voltage U between adjacent coils 1, 2, 3 and thus further makes it possible to dispense with or reduce the need for insulation or phase separation measures.

[0045] The stator module, the stator and the electric rotary machine proposed here provide technical solutions that enable highly efficient operation in a simple, space-saving and cost-effective manner.

[0046] List of reference symbols

[0047] 1 first phase coil

[0048] 2 Second phase coil

[0049] 3 Third phase coil

[0050] 10 phase separators

[0051] 20 stator teeth

[0052] 21 Longitudinal axis of the stator tooth

[0053] 30 grooves

[0054] 40 windings

[0055] 41 first turn

[0056] 42 second turn

[0057] 43 third turn

[0058] 44 phase supply line

[0059] 45 Phase derivation

[0060] 46 winding adjacent to the stator tooth

[0061] 47 radial innermost turn

[0062] 48 radial outermost turn

[0063] 50 star point

[0064] U Voltage between two adjacent coils

Claims

Patent claims 1. Stator module for an electrical rotary machine, comprising a plurality of coils (1, 2, 3) which are assigned to a plurality of phases and are arranged along a circumference, wherein coils (1, 2, 3) of the stator module each form a multi-layer winding (40) of a conductor material wound around a stator tooth (20), and a respective phase supply line (44) of these coils (1, 2, 3) is realized on a turn (46) of the respective coil (1, 2, 3) which is adjacent to the stator tooth (20).

2. Stator module according to claim 1, characterized in that a phase derivation (45) of the respective coil is realized on the radially outermost turn (48) of the coils (1, 2, 3).

3. Stator module according to one of the preceding claims, characterized in that conductor material of windings of adjacent coils (1, 2, 3) are arranged in regions in the same groove (30).

4. Stator module according to one of the preceding claims, characterized in that the coils of the same phase are connected in parallel to at least one voltage source.

5. Stator module according to one of the preceding claims, characterized in that at least one coil (1, 2, 3) of each phase is connected with its radially outermost turn (48) to the star point (50) of a star connection.

6. Stator module according to one of the preceding claims, characterized in that the windings (40) have an insulation which has a maximum thickness of 40 pm.

7. Stator of an electric rotary machine, wherein the stator comprises at least one stator module according to one of claims 1 to 6.

8. Stator according to claim 7, wherein the stator is designed as a stator of an axial flux machine and the axial flux machine comprises two stator modules according to one of claims 1 to 6, wherein i) a rotor of the axial flux machine can be arranged axially between the stator modules, or ii) the two stator modules are aligned to two opposite axial sides and two rotors of the axial flux machine can be arranged axially on both sides of the stator.

9. Stator according to claim 7, characterized in that each of the stator modules has coils with 42 to 62 turns each, which are separately connected to at least one voltage source.

10. An electric rotary machine comprising at least one stator module according to one of claims 1 to 6 or a stator according to one of claims 7 to 9.

11. Electric rotary machine according to claim 9, characterized in that the electric rotary machine is designed for operating voltages of 400 V or more.

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