Stator with cooling channel, and axial flux machine
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-05-02
- Publication Date
- 2026-04-08
AI Technical Summary
Existing stators in axial and radial flux machines face challenges with coolant gap tolerances, leading to high flow resistance and inefficient cooling due to the dependence on spacer elements that only provide support at certain points, resulting in manufacturing tolerances that are difficult to maintain.
The stator design features a winding arrangement where first and second turns of the winding are offset relative to each other, creating defined coolant channels between the winding and the stator tooth, eliminating the need for additional spacer elements and allowing for precise manufacturing of coolant channels with tight tolerances, thereby enhancing cooling efficiency.
This design ensures efficient cooling with reduced manufacturing tolerances and eliminates the need for additional spacer elements, improving the thermal management of stator teeth by creating a consistent and precise coolant channel system.
Smart Images
Figure DE2024100397_28112024_PF_FP_ABST
Abstract
Description
[0001] Stator with cooling channel and axial flux machine
[0002] The present disclosure relates to a stator having a plurality of adjacent stator teeth, wherein at least one stator tooth is completely wound by a winding, and the winding has at least one inner winding layer arranged in close proximity to the stator tooth or directly surrounding the stator tooth, and wherein the winding has a plurality of turns arranged side by side as viewed in the longitudinal direction of the stator tooth. The present disclosure further relates to an axial flux machine.
[0003] Corresponding stators are regularly used in an axial flux machine, particularly in an I-configuration. An axial flux machine is a disk-shaped electrical machine and has a preferably (circular) disk-shaped rotor surrounded by two, preferably ring-shaped stators. An air gap is provided between each stator and the rotor. The stator teeth are arranged in a ring-shaped manner as a circumferential ring and are integrally connected to one another. Between adjacent stator teeth, a winding slot is provided to accommodate the sections of adjacent windings extending in the radial direction (in an axial flux machine) (in the axial direction in a radial flux machine). A yoke (which is not present in axial flux machines in an H-arrangement), which magnetically connects the stator teeth, and the stator teeth together form a stator core. The yoke is mainly located on the back of the stator teeth, i.e.arranged on a side of the stator facing away from the rotor (and running along the outer circumference of the stator teeth). The corresponding winding extends along the outer circumference of each stator tooth. The windings of the stator teeth of the stators change polarity, setting permanent magnets attached to the rotor in motion, so that the axial flux machine rotates about its axis of rotation. Alternatively, corresponding stators can be used in a radial flux machine. The directions of the stator (of an axial flux machine and a radial flux machine) are based on the orientation of the axis of rotation: the axial direction of the stator runs along the axis of rotation, the radial direction of the stator runs perpendicular to the axis of rotation, and the circumferential direction corresponds to a direction of rotation of the stator about the axis of rotation. In an axial flux machine, a longitudinal direction of the stator teeth extends in the axial direction of the stator.In a radial flux machine, the longitudinal direction of the stator teeth extends in the radial direction of the stator. In other words, in axial flux machines and radial flux machines, the longitudinal direction of the stator teeth extends in the direction of the air gap between the rotor and stator.
[0004] The stator core of an axial flux machine preferably consists of electrical steel sheet wound in a ring shape in the circumferential direction, which thus forms multiple layers in the radial direction. The stator core is manufactured, for example, using the punch-winding process, as disclosed, for example, in EP 2 787 610 B1. In this process, a strip-shaped raw material, which forms the electrical steel sheet, is fed to a system. Before the electrical steel sheet is fed to the system, cutouts are punched into the initially strip-shaped electrical steel sheet using a tool. The electrical steel sheet is then wound in the system to form an annular stator core. The cutouts previously introduced into the electrical steel sheet form winding slots for accommodating windings when wound. Accordingly, each stator tooth is laterally surrounded by two winding slots. The winding slots extend in the radial direction.The winding slots, together with the radially first or outer edge and the radially second or inner edge of the respective stator tooth, define the circumference of the stator tooth (in an axial flux machine). A winding associated with the stator tooth extends along the entire circumference of each stator tooth.
[0005] Typically, each winding surrounding a corresponding stator tooth has an inner winding layer located in close proximity to the respective stator tooth, and an outer winding layer adjacent to the outer circumference of the inner winding layer. Typically, both the inner winding layer and the outer winding layer of the winding of each stator tooth have a plurality of turns or winding layers arranged one behind the other in the longitudinal direction of the stator teeth, or in the axial direction of the stator in the case of an axial flux machine. All sections of the turns that extend in the radial direction (in the case of an axial flux machine) (in the axial direction in the case of a radial flux machine) are spaced (in the circumferential direction) from the corresponding stator tooth. These spacings define a gap that is continuous in the longitudinal direction of the stator tooth (in the axial direction in the case of an axial flux machine) between the stator tooth and the inner winding layer.The continuous gap between the inner winding layer and the corresponding stator tooth forms a stator tooth-winding coolant channel. Single-layer windings are also available, which are then designed like the inner winding layer. In this case, the turns of the inner winding layer (as well as those of the outer winding layer) are aligned with each other across the entire winding, viewed in the longitudinal direction of the stator tooth (in the axial direction for axial flux machines).
[0006] Additionally or alternatively, a circumferential clearance is provided between each turn (of the outer winding layer) of the winding of a stator tooth and each turn (of the outer winding layer) of the winding of an adjacent stator tooth. These clearances also define a continuous gap in the longitudinal direction of the stator teeth (in the axial direction for axial flux machines) between the (outer winding layers of) the windings of two adjacent stator teeth. The continuous gap between the (outer winding layers of) the windings of two adjacent stator teeth forms an interwinding cooling channel.
[0007] The coolant channels ensure that all windings exhibit low thermal resistance to the coolant. The combination of the stator tooth winding coolant channel with the interwinding cooling channel offers advantages for efficient cooling not only for multi-layer windings, i.e., windings with inner and outer winding layers, but also for single-layer windings.
[0008] In other words, in axial-flux machines or radial-flux machines, so-called single-tooth windings (windings each wound around a stator tooth) are directly surrounded by liquid cooling. The single-tooth windings are designed in two layers (each with an inner and outer winding layer). To ensure that each winding layer has direct coolant contact, there are two additional coolant gaps in addition to the coolant gap between adjacent windings. These additional coolant gaps are located between the windings and the stator tooth around which they are wound.
[0009] For example, EP 3 108 574 B1 and EP 3 764 526 A1 each disclose a stator in which a coolant gap is provided between the windings of adjacent stator teeth. Furthermore, spacer elements are provided between each stator tooth and the associated winding, which selectively ensure the distance between the winding and the stator tooth over the entire circumference of the stator tooth. Adhesive dots are often used as spacer elements.
[0010] However, the spacers only ensure the distance between the stator tooth and the associated winding at specific points, so that only individual turns of the respective winding are supported. Support is provided both in the area of the winding slots and in the area of the winding overhangs (sections of the windings that extend in the circumferential direction). Neighboring windings are only indirectly supported (via the directly supported windings). Due to tolerances and elasticity between the windings, the resulting coolant gap or distance between the stator tooth and the associated winding is subject to significant tolerances.
[0011] However, due to the strong dependence of the flow resistance on the width of the coolant gap or the distance between the stator tooth and the associated winding (which is clearly disproportionate), close tolerances for the distance between the stator tooth and the associated winding, i.e. for the width of the coolant gap, should be maintained.
[0012] Against this background, the present disclosure aims to provide a stator that reduces or eliminates the disadvantages of the prior art. In particular, a stator or an axial flux machine with a corresponding stator is to be provided, which has coolant gaps / coolant channels, in particular on the sections of the stator teeth extending in the radial direction (in the case of an axial flux machine) (in the axial direction in the case of a radial flux machine), for the direct cooling of stator teeth, which are subject to only small manufacturing tolerances. In other words, the coolant gaps between the stator tooth and the winding and between the adjacent windings are to be designed very precisely / exactly. This object is achieved by the subject matter having the features of the independent patent claim and by the subject matter having the features of the co-ordinate patent claim. Advantageous embodiments are the subject matter of the subclaims.
[0013] The stator according to independent claim 1 has a plurality of mutually adjacent stator teeth. In particular, the stator is intended for use in an axial flux machine, but can alternatively be used in a radial flux machine. The entire circumference of at least one stator tooth, preferably each stator tooth, is / at least one, in particular each, stator tooth is completely wound by (each) a (single-tooth) winding. Preferably, the sections of the windings of adjacent stator teeth extending in the radial direction (in an axial flux machine) (in the axial direction in a radial flux machine) face each other. In particular, the stator has a yoke / laminated core that magnetically and preferably mechanically connects the stator teeth to one another.The yoke is preferably arranged on a side of the stator facing away from the rotor and in particular covers the rear side and also a section of the stator teeth extending in the circumferential direction. Each winding has at least one inner winding layer which is arranged in the immediate vicinity of the respective stator tooth or, to put it another way, surrounds the stator directly, i.e. without another winding layer in between, and preferably an outer winding layer which bears against the outer circumference of the inner winding layer. (Both) the inner winding layer (and the outer winding layer) of each winding has a large number of turns arranged one behind the other or next to the other in the longitudinal direction of the stator tooth (in the axial direction of the stator in the case of an axial flux machine and in the radial direction in the case of a radial flux machine). In an axial flux machine, the longitudinal direction of the stator tooth orof the stator teeth in a direction between the yoke and the air gap (between the rotor and stator). In at least one stator tooth, preferably in at least two adjacent stator teeth, in particular in each stator tooth, the turns of the winding of a stator tooth are (respectively) divided into first turns and second turns, wherein the first turns, in particular of the inner winding layer, of the winding are arranged free of cavities relative to the associated stator tooth or closer to the associated stator core than the second turns, i.e. a tolerance-independent, mechanical support of the first turns of the winding is supported on the associated stator tooth or on an intermediate component, e.g. a base insulation, and between the second turns, in particular of the outer winding layer, of the winding and the associated stator tooth, a stator tooth winding cavity is formed in each case, which forms a stator tooth winding coolant channel.
[0014] The first windings are arranged offset relative to the second windings in the circumferential direction. Thus, a plurality of stator tooth-winding coolant channels are arranged between the inner winding layer of the winding of a stator tooth and the associated stator tooth.
[0015] The offset or different arrangement of the first and second windings relative to each other has the advantage that the stator tooth winding cavities, each of which forms a coolant channel for cooling the stator teeth or their windings, can be manufactured with very tight tolerances due to the dependence on the winding geometry (wire geometry) and the position of the windings relative to each other. In this way, the stator tooth winding coolant channels in such a stator are clearly predefined and enable efficient stator cooling.
[0016] Furthermore, the disclosed design of the stator, with its absence of cavities between the first windings and the stator tooth, has the advantage that no additional spacers are required between the first windings and the stator tooth. Thus, no elevations or additional elements need to be provided on the stator tooth or on an associated intermediate element, such as base insulation. Thus, the winding is supported on the associated stator tooth via the first windings in the form of a linear support, rather than merely point-supported.
[0017] The stator according to the disclosure is advantageously constructed, apart from the properties according to the disclosure, like a stator known from the prior art, in particular a stator for an axial flux machine, which was described above in connection with the prior art. Preferably, the first turns and second turns of a winding are only offset from one another in the sections of the winding extending in the width direction of the stator teeth (in the radial direction in the case of an axial flux machine; in the axial direction in the case of a radial flux machine). In other words, there is no offset between the first turns and the second turns in the region of the winding overhangs, i.e. they are aligned with one another at this point. In other words, the offset orthe different arrangement of first windings and second windings relative to one another, in particular exclusively, is provided in the sections of the winding which extend in the width direction of the stator teeth (in the radial direction in an axial flux machine; in the axial direction in a radial flux machine).
[0018] In particular, it is provided that each turn, in the case of a single-layer winding, consists only of an inner section of the inner winding layer, or, in the case of a two-layer winding, consists of an inner section of the inner winding layer and an outer section of the outer winding layer. The inner section and the outer section are located at the same height in the axial direction.
[0019] It is further preferred if, in the stator, as in the prior art, a winding groove is provided between adjacent stator teeth in each case, in which the sections of adjacent windings of these stator teeth extending in the width direction of the stator teeth (in the radial direction in the case of an axial flux machine; in the axial direction in the case of a radial flux machine) are received.
[0020] Furthermore, it can be provided that the first turns and the second turns of the winding of a stator tooth are arranged alternately with one another in the longitudinal direction of the stator tooth (in the axial direction in an axial flux machine). This has the advantage that for every second turn, namely between the second turns and the stator tooth, a stator tooth winding cavity is provided as a corresponding coolant channel. In this way, a large number of stator tooth winding coolant channels are provided, so that the cooling of the stator tooth or its windings is particularly efficient. It would also be conceivable for two second turns and two first turns to always follow each other in the winding of each stator tooth (as viewed in the axial direction in an axial flux machine).
[0021] It is also conceivable for the individual turns of the winding of a stator tooth to be arranged in alignment with one another in the region of a radially first or outer winding overhang, which (in the case of an axial flux machine) extends along a radially first or outer edge of the stator tooth in the circumferential direction, and for the individual turns of the winding of the same stator tooth to be arranged in alignment with one another in the region of a radially inner winding overhang, which (in the case of an axial flux machine) extends along a radially inner edge of the stator tooth in the circumferential direction. In other words, the individual turns of the winding of a stator tooth are not offset from one another in the radial edge regions of the respective stator tooth. Thus, all turns of a winding have a continuous gap in the region of the winding overhangs to the respective stator tooth.In the area of the winding ends, a flow in the longitudinal direction of the stator teeth (in the axial direction in an axial flux machine) is desired, which would be impeded by the offset of the windings at this point. This would lead to an unnecessary reduction in the flow cross-section. In this respect, this design of the stator improves its cooling efficiency.
[0022] In addition, it can be provided that the first turns of the respective windings of adjacent stator teeth, which are each arranged at the same height in relation to the longitudinal direction of the stator tooth (in the axial direction of the stator in the case of an axial flux machine and in the radial direction in the case of a radial flux machine), form an inter-winding cavity (or spacing) between them, which forms an inter-winding coolant channel, and the second turns of the respective windings of adjacent stator teeth, which are each arranged at the same height in the longitudinal direction of the stator teeth (in the axial direction in the case of an axial flux machine), lie directly against one another without a spacing from one another in the circumferential direction or lie against one another with a spacing from one another in the circumferential direction that is smaller than a dimension of the inter-winding cavity.In other words, an inter-winding cavity or inter-winding coolant channel is provided between the first turns of two adjacent windings, and no inter-winding cavity or inter-winding coolant channel is provided between the second turns of adjacent windings, or only an inter-winding cavity or inter-winding coolant channel is provided that is smaller than the inter-winding cavity or inter-winding coolant channel between the first turns of the two adjacent windings. Thus, not only are a plurality of coolant channels provided between each winding and the associated stator tooth, but a plurality of coolant channels are also provided between adjacent windings. In this way, the cooling of the stator is efficiently improved.In this case, the first turns of a winding are arranged at the same height in the longitudinal direction of the stator teeth (in the axial direction in an axial flux machine) as the first turns of an adjacent winding. The second turns of a winding are also arranged at the same height in the longitudinal direction of the stator teeth (in the axial direction in an axial flux machine) as the second turns of an adjacent winding. Thus, the inter-winding coolant channels (through the second turns of the adjacent windings) are clearly demarcated from one another. This has the advantage that a coolant flows in a defined manner between two adjacent windings and can thus efficiently cool the stator.
[0023] Alternatively, it may be useful to provide an inter-winding cavity in the circumferential direction between the second turns of a winding of a stator tooth and the first turns of a winding of the adjacent stator tooth, which are arranged at the same height in the longitudinal direction of the stator teeth (in the axial direction in an axial flux machine) (and vice versa). In this case, the first turns of a winding (namely all of them) are at the same height in the longitudinal direction of the stator teeth (in the axial direction in an axial flux machine) as the (all) second turns of the adjacent winding. An inter-winding cavity is present between all first turns and second turns of adjacent windings, which are arranged at the same height in the longitudinal direction of the stator teeth (in the axial direction in an axial flux machine). This increases the number of coolant channels in the stator and thus improves the stator's cooling efficiency.
[0024] Furthermore, it is particularly useful if the stator tooth-winding coolant channel and, if applicable, the interwinding coolant channel each extend in the width direction of the stator teeth (in the radial direction for an axial flux machine; in the axial direction for a radial flux machine). This has the advantage that the stator tooth and its associated winding can be cooled along their entire radial extent.
[0025] Preferably, the inter-winding cavities between all first turns and second turns of adjacent windings at the same height in the longitudinal direction of the stator teeth (in the axial direction in an axial flux machine) form a gap that is continuous in the longitudinal direction of the stator teeth (in the axial direction in an axial flux machine), in which gap a phase separator is arranged. In addition to providing electrical insulation between the adjacent windings, the phase separator also forms a mechanical web so that the second turns (in the case of a two-layer winding, the second turns of the outer winding layers) of adjacent windings can each be supported on the phase separator. The phase separator can be supported on the first turns (of the outer winding layers) of adjacent windings, slightly offset in the longitudinal direction of the stator teeth (in the axial direction in an axial flux machine).The offset of the support points in the longitudinal direction of the stator teeth (in the axial direction in the case of an axial flux machine) of the phase separator also ensures a certain additional elasticity in the circumferential direction, so that tolerances of the windings can be cushioned.
[0026] Preferably, the phase separator has phase separator contours at its opposite axial ends. This can advantageously extend the creepage distances.
[0027] In the case where the inter-winding cavities between the first turns of the respective winding of adjacent stator teeth and the inter-winding cavities between the second turns of the respective windings of adjacent stator teeth form a gap that is continuous in the longitudinal direction of the stator teeth (in the axial direction in the case of an axial flux machine), the second turns of the winding of a stator tooth are at the same height in the longitudinal direction of the stator teeth (in the axial direction in the case of an axial flux machine) as the first turns of the winding of the adjacent stator tooth. In this way, the turns of adjacent windings that are at the same height in the longitudinal direction of the stator teeth (in the axial direction in the case of an axial flux machine) are each offset from one another in the same direction. Thus, the inter-winding cavities (orThe cooling medium channels of the adjacent windings are no longer at the same axial height, but offset by one turn (or several turns, depending on the "knitting pattern"). The adjacent windings alternate around the circumference, so that the adjacent windings must have the first and second turns offset from each other.
[0028] Preferably, all turns of a winding are mechanically fixed to each other, for example by gluing, casting or by placing connecting elements around the turns of the respective winding.
[0029] Furthermore, it can be advantageous if a base insulation is arranged between a winding, in particular at least between the first turns, and the associated stator tooth. The base insulation forms electrical insulation between the stator tooth and the associated winding. It thus prevents a short circuit between the stator tooth and the associated winding.
[0030] In addition, the windings of each stator tooth can have two different winding configurations.
[0031] In a first winding configuration, it can be provided that if there is a first turn on one side of the stator tooth in the circumferential direction (e.g. left side), there is a second turn arranged with this first turn at the same height in the longitudinal direction of the stator tooth on the other side of the same stator tooth (e.g. right side) (in the axial direction of the stator in the case of an axial flux machine and in the radial direction in the case of a radial flux machine), and if there is a second turn on one side of the stator tooth in the circumferential direction, there is a first turn arranged with this second turn at the same height in the longitudinal direction of the stator tooth on the other side of the same stator tooth.In other words, the winding of a stator tooth has a plurality of winding layers arranged next to one another in the longitudinal direction of the stator tooth, each of which is composed of the windings belonging to the respective stator tooth, arranged to the left and right of the stator tooth and arranged at the same height in the longitudinal direction of the stator tooth. There are first winding layers, in which there is a first winding to the left of the stator tooth and a second winding to the right of the stator tooth, arranged at the same height as the first winding in the longitudinal direction of the stator tooth. There are also second winding layers, in which there is a second winding to the left of the stator tooth and a first winding to the right of the stator tooth, arranged at the same height as the second winding in the longitudinal direction of the stator tooth. The first and second winding layers of a stator tooth have the same outer diameter and are arranged to the right and left of each other in the circumferential direction.offset to the left. This has the advantage that only one type of winding is required for all stator teeth.
[0032] In a second winding configuration, it can be provided that if there is a first turn on one side of the stator tooth in the circumferential direction, there is a first turn on the other side of the same stator tooth arranged at the same height in the longitudinal direction of the stator tooth as this first turn, and if there is a second turn on one side of the stator tooth in the circumferential direction, there is a second turn on the other side of the same stator tooth arranged at the same height in the longitudinal direction of the stator tooth as this second turn. In other words, the first turn layers here are designed such that there are first turns to the left and right of the respective stator tooth at the same height in the longitudinal direction of the stator tooth. The second turn layers are then designed such that there are second turns to the left and right of the respective stator tooth at the same height in the longitudinal direction of the stator tooth.Thus, the first winding layers each have a smaller outer diameter than the second winding layers.
[0033] Since the first winding configuration requires only one type of winding for all stator teeth, the first winding configuration is preferred over the second winding configuration.
[0034] Furthermore, the above-defined object is achieved by an axial flux machine, preferably in an I-configuration, which has at least one stator according to the disclosure and a rotor, in particular a disk-shaped rotor. If two stators are provided, the rotor is arranged between the two stators. This axial flux machine has the advantages associated with the stator(s) according to the disclosure.
[0035] In other words, the present disclosure relates to a stator in which the windings are wound around the respective stator tooth such that, in the (two) winding slots surrounding the respective stator tooth, the windings (conductors) alternately run near the stator tooth and near the windings (conductors) of the adjacent winding / adjacent winding. In this way, a coolant channel is alternately formed for each winding on the side facing the stator tooth and a coolant channel is alternately formed on the side facing the adjacent winding. A coolant channel is thus delimited in the longitudinal direction of the stator teeth (in the axial direction in an axial flux machine) by the adjacent windings (with the exception of the windings at the edge). The formation of geometrically defined cooling channels, which alternately form with respect to the stator tooth or the adjacent winding, is important.By offsetting the winding turns relative to each other, cavities are created that can be used as coolant channels. These cavities can be manufactured with very tight tolerances due to the dependence of the winding geometry / wire geometry and the position of the windings relative to each other.
[0036] The stator tooth winding coolant channels / “coolant channels to the stator tooth” are limited by inner winding layers of a first winding around a first stator tooth (or a second winding adjacent to the first winding around a second stator tooth that is adjacent to the first stator tooth) of the second turns / “turns at a distance from the stator tooth”, by the stator tooth or by the base insulation on the stator tooth, and by the first turns adjacent to the stator teeth in the longitudinal direction (in the axial direction in the case of an axial flux machine) / “turns adjacent to the stator tooth” of the inner winding layers of the first winding (or the second winding).
[0037] The inter-winding coolant channels / "center coolant channels" are offset by one turn and are limited by the outer winding layers of the first winding of the "windings adjacent to the stator tooth", by the outer winding layers of the second winding of the "windings adjacent to the stator tooth", and by the "windings spaced from the stator tooth" adjacent in the longitudinal direction of the stator teeth (in the axial direction for an axial flux machine). The position of the "windings adjacent to the stator tooth" is defined by the short distance to the stator tooth. The position of the "windings spaced from the stator tooth" is defined by the support to the respective neighboring winding (e.g. outer winding layer of the first winding and outer winding layer of the second winding), by the radial support in the winding overhangs, and by the fixation to the neighboring windings of the "windings adjacent to the stator tooth".
[0038] Preferably, the turns of a winding are mechanically fixed to each other, for example by gluing, casting or by using other connecting elements.
[0039] Alternatively, other "patterns" can be created, i.e., different / different arrangements of first and second turns of the same winding. For example, two adjacent turns spaced from the stator tooth could be alternated with two adjacent turns "adjacent to the stator tooth." It is important to create geometrically defined cooling channels, which alternate with the stator tooth or the adjacent winding.
[0040] Another advantage is that the offset of turns only occurs in radially running areas of the windings in the winding slot. In the areas of the winding overhangs, this offset between adjacent turns in the longitudinal direction of the stator teeth (in the axial direction in an axial flux machine) is not present. This is important so that the layer jump can be carried out efficiently in these areas. Furthermore, in the areas of the winding overhangs, a flow in the longitudinal direction of the stator teeth (in the axial direction in an axial flux machine) is desired, which would be hindered by the offset of the turns (unnecessary reduction of the flow cross-section). Furthermore, it can be seen that the transition between the conductor path with offset (in the slot) and the conductor path without offset (in the winding overhang) occurs in the bending area.
[0041] Viewed in the longitudinal direction of the stator teeth (in the axial direction in an axial flux machine), the turns of a first winding "A" are offset around a first stator tooth and of an adjacent winding "B" around a second stator tooth adjacent to the first stator tooth in the same direction. In this case, an offset in the direction of a first stator tooth and in the direction of a second stator tooth adjacent to the first stator tooth alternate in the longitudinal direction of the stator teeth (in the axial direction in an axial flux machine).
[0042] Thus, the "center coolant channels" of windings "A" and "B" are no longer opposite each other (at the same axial height), but offset by one turn (or several turns depending on the "knitting pattern"). Around the circumference, windings "A" and "B" alternate depending on the adjacent stator tooth, so two different windings (type "A" and type "B") are required.
[0043] It is also advantageous if the windings have a first winding configuration. In this case, the windings (or their respective turns) are all wound with approximately the same size. The cooling channels are formed by winding the turns alternately offset to the left and right relative to the adjacent turns. In the first winding configuration, the individual windings each consist of several winding layers and one or more winding layers (e.g., one outer and one inner winding layer).
[0044] The windings of a first winding layer are, for example, offset to the right (first windings), so that to the left of the outer winding layer of a first winding, in a first winding slot, there is a coolant channel to the phase separator (inter-winding cavity). To the left of the inner winding layer of the first winding, in a second winding slot, there is a coolant channel to the (iron core of the) stator tooth(s) (stator tooth winding cavity). To the left of the outer winding layer of the second winding, in the second winding slot, there is a coolant channel to the phase separator (inter-winding cavity). To the left of the inner winding layer of the second winding, in a third winding slot, there is a coolant channel to the (iron core of the) stator tooth(s) (stator tooth winding cavity).
[0045] The reverse applies to the second winding layers, which are arranged directly below the first winding layer. Further winding layers are designed similarly to the first two winding layers. The first winding layers (winding layers with an odd numbering index, i.e., first, third, etc. winding layer) have a similar orientation to one another. Accordingly, the second winding layers (winding layers with an even numbering index, i.e., second, fourth, etc. winding layer) also have a similar orientation to one another, although this orientation differs from the first winding layers.
[0046] It is also possible for the offset to change with the winding layer. However, the "knitting pattern" can also be designed differently, for example, by staggering two or more adjacent winding layers in blocks relative to the adjacent blocks of winding layers.
[0047] In addition to providing electrical insulation between adjacent windings, the phase separator also forms a mechanical bridge, allowing the outer layers of winding "A" to rest on the phase separator, which rests slightly offset along the longitudinal direction of the stator teeth (in the axial direction in an axial flux machine) against the outer winding layers of winding "B." The phase separator has contours at its axial ends to increase creepage distances.
[0048] The offset of the support points in the longitudinal direction of the stator teeth (in the axial direction in the case of an axial flux machine) of the phase separator can also ensure a certain additional elasticity in the circumferential direction, so that tolerances of the coils can be cushioned.
[0049] Furthermore, adjacent windings can also be glued together to create a ring-shaped component in which all windings / coils are connected.
[0050] The phase separator between adjacent windings can also be omitted (e.g., by gluing / casting adjacent windings together, etc.). This has the following advantages:
[0051] Slightly enlarged cooling surface to the conductors,
[0052] Minimal tolerance influences on the cross-sections of the cooling surfaces, resulting in minimal variation in the cooling performance of the individual turns / windings. The disclosure is explained below with the help of drawings. They show:
[0053] Fig. 1 is a cross-sectional view of two adjacent stator teeth with associated winding in a second winding configuration in an arrangement according to a first embodiment;
[0054] Fig.2 is a cross-sectional view of two adjacent windings in an arrangement according to a second embodiment;
[0055] Fig. 3 is a perspective view of adjacent windings between which a phase separator is arranged;
[0056] Fig. 4 is a perspective sectional view of the radially outer end of a stator tooth with associated outer winding head;
[0057] Fig. 5 is a cross-sectional view of two adjacent stator teeth with associated winding in a first winding configuration in an arrangement according to a second embodiment; and
[0058] Fig. 6 is a perspective sectional view of adjacent windings according to the first winding configuration.
[0059] The figures are merely schematic and serve only to clarify the invention. The same elements are designated by the same reference numerals.
[0060] Fig. 1 is a cross-sectional view of a stator 1 for an axial flux machine with two adjacent stator teeth 2, 3. The first stator tooth 2 is completely wound by a first winding 4. The first radial section of this winding is shown in Fig. 1 on the left side of the first stator tooth 2 and the second radial section of this winding is shown in Fig. 1 on the right side of the first stator tooth 2. The second stator tooth 3 is also completely wound by a second winding 5. The first radial section of this winding is shown in Fig. 1 on the left side of the second stator tooth 3 and the second radial section of this winding is shown in Fig. 1 on the right side of the second stator tooth 3. In the area in which the first stator tooth 2 and the second stator tooth 3 face each other, the first winding 4 is arranged adjacent to the second winding 5.The first winding 4 faces the adjacent second winding 5 and is in partial contact with the second winding 5.
[0061] A yoke 6 magnetically connects the stator teeth 2, 3 and all other stator teeth of stator 1 (not shown here). The dashed line JS shows the dividing line between yoke 6 and stator teeth 2, 3.
[0062] The first winding 4 has an inner winding layer 4.1, which is arranged in the immediate vicinity of the first stator tooth 2. The first winding 4 has an outer winding layer 4.2, which rests on the outer circumference of the inner winding layer 4.1. This structure also applies to the second winding 5 (and all further windings). The second winding 5 has an inner winding layer 5.1, which is arranged in the immediate vicinity of the second stator tooth 3. The second winding 5 has an outer winding layer 5.2, which rests on the outer circumference of the inner winding layer 5.1. The outer winding layer 5.2 on the right side of the second stator tooth 3 is only partially shown here. Accordingly, the outer winding layer 4.2 or 5.3 is located further away from the corresponding stator tooth 2 or 3 in the circumferential direction U than the corresponding inner winding layer 4.1 or 5.1. It can be seen that the outer winding layers 4.2, 5.2 adjacent windings 4, 5 face each other (and also touch each other in sections).
[0063] Both the inner winding layer 4.1 or 5.1 and the outer winding layer 4.2 or 5.2 of each winding 4, 5 (and also of every other winding) have a plurality of turns 7, 8 arranged next to one another, one behind the other, or one above the other, as viewed in the axial direction A of the stator 1. Here, the longitudinal direction of the stator teeth 2, 3 extends in the axial direction A of the stator 1. The turns of a winding are arranged one above the other in rows. Each row has either a first turn 7 consisting of a first turn section 7.1 and a second turn section 7.2, or a second turn consisting of a first turn section 8.1 and a second turn section 8.2. The first winding section 7.1 is a section of the first winding 7 of an inner winding layer 4.1, 5.1, and the second winding section 7.2 is a section of the first winding 7 of an outer winding layer 4.2, 5.2. The first winding section 8 is correspondingly.1 is a section of the second turn 8 of an inner winding layer 4.1, 5.1, and the second turn section 8.2 is a section of the second turn 8 of an outer winding layer 4.2, 5.2. The first turns 7, each arranged in a row, are composed of the first and second turn sections 7.1, 7.2 arranged at the same height in the axial direction A. The second turns 8, each arranged in a row, are composed of the first and second turn sections 8.1, 8.2 arranged at the same height in the axial direction A.
[0064] It can be seen that the first windings 7 do not form a hollow space between themselves and the corresponding stator tooth 2, 3. It can also be seen that the second windings 8 form a stator tooth winding hollow space 9 between themselves and the respective stator tooth 2, 3, which forms a stator tooth winding coolant channel. The adjacent windings 4, 5 are completely electrically insulated from the stator teeth 2, 3 and the yoke 6 by a base insulation 10. The base insulation 10 extends in the axial direction along the respective outer edge of the stator teeth 2, 3 and extends immediately adjacent thereto in the circumferential direction U along the yoke 6. In other words, the base insulation lines the slot base of each winding slot 11. In each winding slot 11, the windings of adjacent stator teeth are arranged next to one another.
[0065] In the present Fig. 1, the adjacent windings 4, 5 are arranged relative to one another according to a first embodiment. This means that the first turns 7 of the first winding 4 and the first turns 7 of the second winding 5 are each located at the same height in the axial direction. Thus, between the first turns 7 of the first winding 4 and the second winding 5, there is an inter-winding cavity 12, which forms a corresponding inter-winding coolant channel.
[0066] In Fig. 1, the lower edge shown faces a rotor (not shown).
[0067] The outermost turns of the adjacent windings (here the first turns 7), which face the rotor, are completely sealed in the axial direction A by a seal 13. The seal 13 thus extends in the circumferential direction U and insulates the windings from an air gap formed between the stator 1 and the rotor.
[0068] In Fig. 1, the windings 4, 5 are each shown in the second winding configuration. This means that the first winding 4 around the first stator tooth 2 and the second winding 5 around the second stator tooth 3 (alternating) each have first windings 7 in the first winding layers and second windings 8 in the second winding layers at the same height in the axial direction A.
[0069] The section of stator teeth 2, 3 and windings 4, 5 shown in Fig. 1 applies to the entire stator 1. For the sake of clarity, however, only a section of stator 1 is shown here.
[0070] Fig. 2 shows a cross-sectional view of two adjacent windings 4, 5 in an arrangement according to a second embodiment. The structure of the stator 1 shown in Fig. 2 is essentially similar to that of the stator 1 shown in Fig. 1. The differences from the stator 1 shown in Fig. 1 are described below.
[0071] The stator 1 according to Fig. 2 differs from the stator 1 according to Fig. 1 in the arrangement of the adjacent windings 4, 5 relative to one another. In the second embodiment, the second windings 8 of the first winding 4 are located at the same height in the axial direction A as the first windings 7 of the second winding 5. This means that the windings 7, 8 of the adjacent windings 4, 5 located in a row are offset in the same direction. Thus, all of the windings 7, 8 of the adjacent windings 4, 5 located in a row enclose an inter-winding cavity 12 between them. The inter-winding cavities 12 arranged one behind the other, one above the other, or next to one another in the axial direction A thus form a gap that is continuous in the axial direction A. In the present example, a phase separator 14 is arranged in this gap. The phase separator 14 thus separates the outer winding layers 4.2, 5.2 of the adjacent windings 4, 5 from each other.In addition, the phase separator 14 has phase separator contours 15 at its opposite axial ends. This can advantageously extend the creepage distances. Fig. 3 shows a perspective view of adjacent windings 4, 5, between which a phase separator 14 is arranged. The phase separator 14 is arranged between the adjacent windings 4, 5 along the entire radial extent of the latter. The phase separator contour 15 (only one shown in this view) overlaps the outer turns of the two adjacent windings 4, 5, as viewed in the axial direction A.
[0072] The radially outer ends of the windings 4, 5, i.e., their outer winding heads 4.3, 5.3, are completely wrapped by a fixing element 16. The radially inner ends of the windings 4, 5, i.e., their inner winding heads 4.4, 5.4, are also completely wrapped by a fixing element 16. The fixing elements 16 fix the individual turns 7, 8 of a winding 4, 5 to one another and prevent or reduce slippage of the turns 7, 8 of a winding 4, 5 relative to one another.
[0073] Fig. 4 shows a perspective sectional view of the radially outer end of the stator teeth 2, 3 with the associated outer winding overhang 4.3, 5.3. Here, the stator teeth 2, 3 are shown from their rear view, which are concealed by the yoke 6. Nevertheless, for easier understanding, the stator teeth 2, 3 are shown, even though at least the stator tooth 3 is completely concealed by the yoke 6 here. The section in the radial direction R is taken through the first stator tooth 2. It can be seen that the turns of the inner winding layer 4.1 and the outer winding layer 4.2, which are arranged in a row, are aligned with one another across the entire axial direction A. This means that in the outer winding overhang 4.3 of the first winding 4 (and also in all other windings), there is no offset between turns arranged in series. Preferably, this is also provided in the inner winding head 4.4 (which is not shown here) of the winding 4 (and also in all other windings).In order, on the one hand, to provide for an offset of the turns arranged in series in their sections extending in the radial direction for the windings and, on the other hand, to avoid an offset of the turns arranged in series in their sections extending in the circumferential direction U, a compensation of the offset of the sections of the windings extending in the radial direction is provided in the radius region, i.e. in the transition region between sections of the windings extending in the radial direction R and sections of the windings extending in the circumferential direction U.
[0074] Fig. 5 is a cross-sectional view of a stator 1 for an axial flux machine 1 with two adjacent stator teeth 2, 3. Essentially, Fig. 5 is constructed similarly to Fig. 1. Only the differences between Fig. 5 and Fig. 1 are explained below.
[0075] First of all, it can be seen that in Fig. 5, in contrast to Fig. 1, the adjacent windings 4, 5 are arranged relative to one another in the second embodiment. This means that the second turns 8 of the first winding 4 are at the same height in the axial direction A as the first turns 7 of the second winding 5. This means that the turns 7, 8 of the adjacent windings 4, 5 located in a row are offset in the same direction. Thus, all of the turns 7, 8 of the adjacent windings 4, 5 located in a row enclose an inter-winding cavity 12 between them. A phase separator 14 is arranged in this inter-winding cavity 12. However, this can optionally be omitted.
[0076] A further difference between Fig. 5 and Fig. 1 is that the windings 4, 5 are arranged in the first winding configuration. This means that the first winding 4 and the second winding 5, in all first winding layers, have first windings 7 to the left of the stator tooth 2, 3 and second windings 8 to the right of the stator tooth 2, 3 at the same height in the axial direction A (the right side of the stator tooth 3 is omitted). In all second winding layers, second windings 8 are arranged to the left of the stator tooth 2, 3 and first windings 7 to the right of the stator tooth 2, 3 at the same height in the axial direction A (the right side of the stator tooth 3 is omitted). The first and second winding layers are arranged alternately (directly one after the other) in the axial direction A.
[0077] Fig. 6 is a perspective sectional view of adjacent windings 4, 5 according to the first winding configuration. Thus, in the first winding layers, the left section of the windings 4, 5 contains first turns 7, and in the right section of the windings 4, 5, the second turns 8 are arranged at the same height in the axial direction A. In the second winding layers, the left section of the windings 4, 5 contains second turns 8, and in the right section of the windings 4, 5, the first turns 7 are arranged at the same height in the axial direction A.
[0078] In Fig. 6, it can also be seen that the second turns 8 of the first winding 4 are located at the same height in the axial direction A as the first turns 7 of the second winding 5 adjacent to the first winding 4 (second embodiment). The phase separator contour 15 can also be seen between the adjacent windings 4, 5. The radially inner ends of the windings 4, 5, i.e., their inner winding heads 4.4, 5.4, are each completely wrapped by a fixing element 16.
[0079] It should be noted that even if only one or two stator teeth 2, 3 of an axial flux machine with associated winding 4, 5 are shown in the figures above, the corresponding structure described above applies to all stator teeth or their windings.
[0080] List of reference symbols
[0081] 1 stator
[0082] 2 first stator tooth
[0083] 3 second stator tooth
[0084] 4 first winding
[0085] 4.1 inner winding layer of the first winding
[0086] 4.2 outer winding layer of the first winding
[0087] 4.3 outer winding head of the first winding
[0088] 4.4 inner winding head of the first winding 5 second winding 5.1 inner winding layer of the second winding 5.2 outer winding layer of the second winding
[0089] 5.3 outer winding head of the second winding
[0090] 5.4 inner winding head of the second winding 6 yoke
[0091] 7 first turns
[0092] 7.1 first turns of the inner winding layer
[0093] 7.2 first turns of the outer winding layer 8 second turns
[0094] 8.1 second turns of the inner winding layer
[0095] 8.2 second turns of the outer winding layer 9 Stator tooth winding cavity / coolant channel
[0096] 10 Basic insulation
[0097] 11 Winding groove
[0098] 12 Inter-winding cavity / coolant channel
[0099] 13 Sealing
[0100] 14 phase separators
[0101] 15 phase separator contours
[0102] 16 Fixing elements A Axial direction R Radial direction U Circumferential direction
Claims
Patent claims 1. Stator (1) with a plurality of mutually adjacent stator teeth (2, 3), wherein at least one stator tooth (2, 3) is completely wound by a winding (4, 5) and the winding (4, 5) has at least one inner winding layer (4.1, 5.1 ) which is arranged in the immediate vicinity of the stator tooth (2, 3) or directly surrounds the stator tooth (2, 3), and wherein the winding (4, 5) has a plurality of turns (7, 8) arranged next to one another as viewed in the longitudinal direction of the stator tooth (2, 3), characterized in that the turns (7, 8) of the winding (4, 5) of a stator tooth (2, 3) are each divided into first turns (7) and second turns (8), wherein the first turns (7) of the winding (4, 5) are arranged free of cavities relative to the associated stator tooth (2, 3) or closer to the associated stator tooth (2, 3) than the second turns (8), and a stator tooth-winding coolant channel is formed between the second turns (8) of the winding (4, 5) and the associated stator tooth (2, 3). is.
2. Stator (1) according to claim 1, characterized in that the first windings (7) or respective groups of the first windings (7) and the second windings (8) or respective groups of the second windings (8) of the winding (4, 5) of a stator tooth (2, 3) are arranged alternately with one another as viewed in the axial direction (A).
3. Stator (1) according to claim 1 or 2, characterized in that the individual turns (7, 8) of the winding (4, 5) of a stator tooth (2, 3) are each arranged in alignment with one another in the region of an outer winding head (4.3, 5.3), which extends along a radially outer edge of the stator tooth (2, 3) in the circumferential direction (U), and / or the individual turns (7, 8) of the winding (4, 5) of the same stator tooth (2, 3) are each arranged in alignment with one another in the region of an inner winding head (4.4, 5.4), which extends along a radially inner edge of the stator tooth (2, 3) in the circumferential direction (U).
4. Stator (1) according to one of claims 1 to 3, characterized in that the first turns (7) of the respective windings (4, 5) of mutually adjacent stator teeth (2, 3), which are each arranged at the same height with respect to the longitudinal direction of the stator tooth (2, 3), each form an inter-winding cavity (12) between them, which forms an inter-winding coolant channel, and the second turns (8) of the respective windings (4, 5) of mutually adjacent stator teeth (2, 3), which are each arranged at the same height with respect to the longitudinal direction of the stator tooth (2, 3), directly abut one another without a distance in the circumferential direction (U) from one another or abut one another with a distance in the circumferential direction (U) from one another that is smaller than a dimension of the inter-winding cavity (12).
5. Stator (1) according to one of claims 1 to 3, characterized in that between the first turns (7) of a winding (4) of a stator tooth (2) and the second turns (8) of a winding (5) of the adjacent stator tooth (3), each arranged at the same height in the longitudinal direction of the stator tooth (2, 3), an inter-winding cavity (12) forming an inter-winding coolant channel is provided in the circumferential direction (U), and between the second turns (8) of a winding (4) of a stator tooth (2) and the first turns (7) of a winding (5) of the adjacent stator tooth (3), each arranged at the same height in the longitudinal direction of the stator tooth (2, 3), an inter-winding cavity (12) forming an inter-winding coolant channel is provided in the circumferential direction (U) is provided.
6. Stator (1) according to one of claims 1 to 5, characterized in that each stator tooth winding coolant channel (9) and optionally each inter-winding coolant channel (12) each extends in the width direction of the stator tooth (2, 3).
7. Stator (1) according to claim 4 or 5, characterized in that the inter-winding cavities (12) form a gap which is continuous in the longitudinal direction of the stator tooth (2, 3), in which gap a phase separator (14) is arranged which prevents a coolant flow in the inter-winding coolant channel.
8. Stator (1) according to one of claims 1 to 7, characterized in that, if a first turn (7) is present on one side of the stator tooth (2, 3) in the circumferential direction (U), on the other side of the same stator tooth (2, 3) there is a second turn (8) arranged with this first turn (7) at the same height in the longitudinal direction of the stator tooth (2, 3), and if a second turn (8) is present on one side of the stator tooth (2, 3) in the circumferential direction (U), on the other side of the same stator tooth (2, 3) there is a first turn (7) arranged with this second turn (8) at the same height in the longitudinal direction of the stator tooth (2, 3).
9. Stator (1) according to one of claims 1 to 7, characterized in that, if a first turn (7) is present on one side of the stator tooth (2, 3) in the circumferential direction (U), on the other side of the same stator tooth (2, 3) there is a first turn (7) arranged with this first turn (7) at the same height in the longitudinal direction of the stator tooth (2, 3), and if a second turn (8) is present on one side of the stator tooth (2, 3) in the circumferential direction (U), on the other side of the same stator tooth (2, 3) there is a second turn (8) arranged with this second turn (8) at the same height in the longitudinal direction of the stator tooth (2, 3).
10. Axial flux machine comprising at least one stator (1) according to one of the preceding claims and a rotor, wherein in the case of two stators (1) the rotor is arranged between the two stators (1).